ARTICLE | doi:10.20944/preprints201908.0075.v1
Subject: Computer Science And Mathematics, Information Systems Keywords: subcarrier level spectrum sensing；spectrum utilization
Online: 6 August 2019 (12:20:09 CEST)
Abstract: As the massive deployment of the heterogeneous IoT devices in the coexisting environment such as smart homes，Traditional channel-based spectrum sharing algorithms such as CSMA has great limitations to further optimize spectrum utilization. Therefore, exploring more efficient spectrum sensing algorithm becomes hot topic these years. This paper proposes Subcarrier-Sniffer, which utilizes Channel State Information (CSI) to sense the subcarrier-level detailed status of the spectrum. In order to evaluate the performance of Subcarrier-Sniffer, we implemented Subcarrier-Sniffer by USRP B200min, and the experimental results show that when the distance between Subcarrier-Sniffer and the monitored devices is not great than 7 m, the accuracy of subcarrier-level spectrum sensing could achieve 100% in our settings.
ARTICLE | doi:10.20944/preprints202206.0319.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: Cognitive Radio; MATLAB; WSN; Spectrum; Radio Frequency
Online: 23 June 2022 (03:48:36 CEST)
The vast rise in the number of Internet-connected devices necessitates a more accessible spectrum. As a result, Cognitive Radio was already proposed as a solution to the problem of restricted spectrum resources by utilizing available spectrum which is assigned to primary users. This method allows the secondary user to utilize the spectrum whenever the primary user is not using it, and it does so without intruding with the primary user. Whenever the secondary user detects the spectrum, it faced some issues, such as complexity in sensing leading to a lack of noise value, and the primary user is hidden to all secondary users. In order to tackle these challenges, an adaptive threshold matched filter detector and a cooperative matched filter detector are utilized in this paper to detect the spectrum. The probability of detection (Pd), probability of miss detection (Pm), and probability of false alarm (Pf) are the metrics used to assess sensing accuracy. To simulate suggested detectors, the MATLAB R2020a software was utilized. In comparison to earlier studies, the simulation conclusions reveal that the detection process starts with lower SNR values.
ARTICLE | doi:10.20944/preprints202307.2084.v1
Subject: Computer Science And Mathematics, Signal Processing Keywords: cognitive radio; dynamic spectrum access; spectrum sensing; embedding parameters; false nearest neighbours; recurrence quantification analysis
Online: 31 July 2023 (10:08:43 CEST)
This paper addresses the problem of non-cooperative spectrum sensing in very low signal noise ratio (SNR) conditions. In our approach, detecting an unoccupied bandwidth consists to detect the presence or absence of a communication signal on this bandwidth. Major well known communication signals may contain hidden periodicities, we use the Recurrence Quantification Analysis (RQA) to reveal the hidden periodicities. RQA is very sensitive to a reliable estimation of the phase space dimension m or the time delay τ. In view of the limitations of algorithms proposed in the literature, we have proposed a new algorithm to estimate simultaneously the optimal values of m and τ. The new proposed optimal values allow the states reconstruction of the observed signal and then the estimation of the distance matrix. This distance matrix has particular properties which we have exploited to propose the Recurrence Analysis based Detector (RAD). RAD can detect a communication signal in a very low SNR condition. Using Receiver Operating Characteristic curves, our experimental results corroborate the robustness of our proposed algorithm comparing to classical widely used algorithms.
ARTICLE | doi:10.20944/preprints201712.0179.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: cognitive radio; cognitive vehicular networks; spectrum sensing; sensing/reporting channel; correlated rayleigh fading channel; hard fusion
Online: 25 December 2017 (10:42:53 CET)
An explosive growth in vehicular wireless services and applications gives rise to spectrum resource starvation. Cognitive radio has been used to vehicular networks to mitigate the impending spectrum starvation problem by allowing vehicles to fully exploit spectrum opportunities unoccupied by licensed users. Efficient and effective detection of licensed user is a critical issue to realize cognitive radio applications. However, spectrum sensing in vehicular environments is a very challenging task due to vehicles mobility. For instance, vehicle mobility has a large effect on the wireless channel, thereby impacting the detection performance of spectrum sensing. Thus, gargantuan efforts have been made in order to analyze the fading properties of mobile radio channel in vehicular environments. Indeed, numerous studies have demonstrated that the wireless channel in vehicular environments can be characterized by a temporally correlated Rayleigh fading. In this paper, we focus on energy detection for spectrum sensing and a counting rule for cooperative sensing based on Neyman-Pearson criteria. Further, we go into the effect of the sensing and reporting channels condition on spectrum sensing performance under temporally correlated Rayleigh sensing channel. For local and cooperative sensing, we derive some alternative expressions for average probability of miss detection. The pertinent numerical and simulating results are provided to further validate our theoretical analyses under a variety of scenarios.
ARTICLE | doi:10.20944/preprints202112.0450.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: polymerization catalysis; machine learning; nanoclusters; DFT; Raman spectrum; IR spectrum; Lewis bases
Online: 28 December 2021 (14:04:10 CET)
Understanding the structure and properties of MgCl2/TiCl4/ID nanoclusters is a key to uncover the origin of Ziegler-Natta catalysis. In this work MgCl2/TiCl4 nanoplatelets derived by machine learning and DFT calculations have been used to model the interaction with ethyl-benzoate EB (as internal donor) with available exposed sites of binary TixCly/MgCl2 systems. The influence of vicinal Ti2Cl8 and coadsorbed TiCl4 on energetic, structural and spectroscopic behaviour of EB has been considered. The adsorption of homogeneous-like TiCl4EB and TiCl4(EB)2 at the various surface sites have been also simulated. Calculations have been carried out by employing B3LYP-D2 and M06 functionals. The adducts have been characterized by computing IR and Raman spectra that have been found to provide specific fingerprints useful to identify surface species; IR spectra have been successfully compared to available experimental data.
ARTICLE | doi:10.20944/preprints202011.0238.v1
Subject: Engineering, Automotive Engineering Keywords: cognitive radio; deep learning; multidimensions; real-world spectrum measurement; spectrum occupancy prediction
Online: 6 November 2020 (10:33:22 CET)
In cognitive radio systems, identifying spectrum opportunities is fundamental to efficiently use the spectrum. Spectrum occupancy prediction is a convenient way of revealing opportunities based on previous occupancies. Studies have demonstrated that usage of the spectrum has a high correlation over multidimensions which includes time, frequency, and space. Accordingly, recent literature uses tensor-based methods to exploit the multidimensional spectrum correlation. However, these methods share two main drawbacks. First, they are computationally complex. Second, they need to re-train the overall model when no information is received from any base station for any reason. Different than the existing works, this paper proposes a method for dividing the multidimensional correlation exploitation problem into a set of smaller sub-problems. This division is achieved through composite two-dimensional (2D)-long short-term memory (LSTM) models. Extensive experimental results reveal a high detection performance with more robustness and less complexity attained by the proposed method. The real-world measurements provided by one of the leading mobile network operators in Turkey validate these results.
ARTICLE | doi:10.20944/preprints202102.0360.v1
Subject: Physical Sciences, Fluids And Plasmas Physics Keywords: turbulence; capillary wave; spectrum; anisotropy
Online: 17 February 2021 (09:59:01 CET)
We consider the developed turbulence of capillary waves on shallow water. Analytic theory shows that an isotropic cascade spectrum is unstable with the respect to small angular perturbations, in particular, to spontaneous breakdown of the reflection symmetry and generation of nonzero momentum. By computer modeling we show that indeed a random pumping, generating on average zero momentum, produces turbulence with a nonzero total momentum. A strongly anisotropic large-scale pumping produces turbulence whose degree of anisotropy decreases along a cascade. It tends to saturation in the inertial interval and then further decreases in the dissipation interval. Surprisingly, neither the direction of the total momentum nor the direction of the compensated spectrum anisotropy is locked by our square box preferred directions (side or diagonal) but fluctuate.
ARTICLE | doi:10.20944/preprints202106.0507.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: spectrum sharing, collaborative spectrum sharing, policy-based sharing, transmission opportunities, rendezvous channels, policy interpreter
Online: 21 June 2021 (11:35:10 CEST)
This paper describes some of the challenges that need to be addressed in order to develop collaborative spectrum sharing systems. The importance of these challenges stems from the assumption that rules for spectrum sharing can change after the deployment of radio networks and the whole system must be able to adapt to them. To address such a requirement, we used a policy-based approach in which transmissions are controlled by a policy interpreter system, and the policies can be modified during system operation. Our primary goal was to develop a prototype of such a system. In this paper, we outline the implementation of policy interpretation, automatic generation of transmission opportunities in case a request for transmission is denied by the policy reasoner, and the generation of rendezvous channels for the synchronization of otherwise asynchronously running software defined radios.
ARTICLE | doi:10.20944/preprints202310.0899.v1
Subject: Physical Sciences, Applied Physics Keywords: betatron radiation; LWFA; self injection; spectrum
Online: 13 October 2023 (11:42:20 CEST)
X-rays production through betatron radiation emission from electron bunches is a valuable resource for several research fields. The EuAPS (EuPRAXIA Advanced Photon Sources) project, within the framework of the EuPRAXIA project, aims to provide 1-10 keV photons (soft X-rays) developing a compact plasma-based system designed to exploit self-injection processes that occur in highly nonlinear laser-plasma interaction (LWFA) to drive electron betatron oscillations. Since the emitted radiation spectrum, intensity, angular divergence, and possible coherence strongly depend on the properties of the self-injected beam, accurate preliminary simulations of the process are necessary to evaluate the optimal diagnostic device specifications. Dedicated tools for these tasks are under development: electron trajectories from particle-in-cell (PIC) simulations are currently undergoing numerical analysis through the calculation of retarded fields and spectra for various plasma and laser parameter combinations. At the same time, an analytical approach is being examined to obtain an expression for the emitted spectrum, assuming linear or quadratic electron energy variation. Code structure and some trajectories analysis results are presented.
ARTICLE | doi:10.20944/preprints202307.1224.v1
Subject: Engineering, Telecommunications Keywords: 6G; Licensed spectrum distribution; Blockchain; Fairness
Online: 18 July 2023 (14:16:00 CEST)
Spectrum distribution is a classical licensed spectrum accessing method in mobile communication networks. The licensed idle spectrum resources are authorized and distributed from spectrum owners to mobile users. However, the exponential growth of user capacity brings excessive load pressure on the traditional centralized network architecture. As lack of sufficient supervision and penalty measures, dishonest behaviors of spectrum owners and spectrum users will lead to the unfair status in the distribution process. As a result, the honest participants’ interest will be harmed. As an important supporting infrastructure of Internet of things technology, 6G cannot completely follow the existing spectrum distribution method. Towards 6G network spectrum distribution, an blockchain based licensed spectrum fair distribution method is proposed. A lightweight consensus mechanism named as proof of trust (PoT) is applied to reduce computational power consumption and consensus time overhead. We deploy the method on the Ethereum test chain, theoretical analysis and experimental results demonstrate the fairness, effectiveness and security of the method.
REVIEW | doi:10.20944/preprints202305.1435.v1
Subject: Medicine And Pharmacology, Anatomy And Physiology Keywords: Autism spectrum disorder; microbiota; meta-analysis
Online: 19 May 2023 (10:54:34 CEST)
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with high heterogeneity and has a prevalence of 0.7% to 3.2% in children. Gut microbiota are a collection of microorganisms that inhabit in human guts, which can produce various metabolites that affect the homeostasis and functions of nervous and endocrine systems. There are many studies on the relationship between various gut microbiota and ASD, but the alteration pattern of microbial profiles in ASD children is not conclusive. In order to more robustly describe the deregulations of gut microbiota compositions in ASD, a meta-analysis was performed. The related investigations from PubMed, Embase and Web of Science were collected and manually reviewed. By procedure, 26 eligible studies until 2023, with a total of 1021 ASD and 951 typically developed children and adolescents, were included for the meta-analysis. RevMan5.4 was used to assess the overall effect of 8 microbes at the phylum level and 19 microbes at the genus level. Results demonstrated relatively up-regulated abundance of Bacteroidetes, Verrucomicrobia, Bacteroides, Clostridium, Dorea and Sutterella, and down-regulated abundance of Proteobacteria, Bifidobacterium, Coprococcus, and Akkermansia in ASD children, indicating partly agreement in the ASD-associated microbes, albeit the heterogeneity of ASD.
ARTICLE | doi:10.20944/preprints202311.0956.v1
Subject: Computer Science And Mathematics, Hardware And Architecture Keywords: embedded system; FPGA; Z80; ZX Spectrum+
Online: 15 November 2023 (10:35:30 CET)
The ZX Spectrum was a popular 8-bit home computer by Sinclair Research in the 80s. Even though some of these computers may still work, the audio tapes, the TV with an analog tuner and the micro-switch joystick, used with the original ZX Spectrum, nowadays are outdated and hard to find in good working order or replicate. Since many other old closed systems are also very difficult to update to support modern peripherals, there is a necessity to provide a methodology to adapt such systems to support new peripherals while being compatible with existing software. The work proposed in this paper is focused on recreating a ZX Spectrum+/48k computer and interface it with modern peripherals on an FPGA. This is accomplished by adding a co-processor to assist with the control of the new peripherals which would either require to complex architectural changes to the original system and in the end it would perform poorly due to the low performance of the Z80 CPU. This work distances from previous ones on emulating a ZX Spectrum since it focuses on the use of different upgraded peripherals and the use of a NIOS II soft-processor as a co-processor to manage the SD Card accesses. A demonstration of the proposed modernized architecture was made by successfully running a diagnostics ROM and playing original ZX Spectrum games from an SD card for game with a PS/2 keyboard and a pair of joysticks.
REVIEW | doi:10.20944/preprints202308.1236.v1
Subject: Computer Science And Mathematics, Signal Processing Keywords: wearable technology; autism spectrum disorder; physiological signals
Online: 17 August 2023 (12:59:38 CEST)
Research on wearable solutions for individuals with autism spectrum disorder (ASD) has been conducted to detect stress. However, studies on stress detection for an individual with ASD have been limited, especially on how it should design for individuals with ASD. Wearable solutions may be a tool for parents and caregivers for emotional monitoring for individuals with ASD who have a high risk of experiencing very stressful. However, wearable solutions for individuals with ASD may differ from those without ASD. Individuals with ASD have sensory sensitiveness; therefore, they do not tolerate any accessory type or discomfort to use. We used the Scopus, PubMed, WoS, and IEEE-Xplore databases to answer different research questions related to wearable solutions for individuals with ASD, physiological parameters, and algorithms of artificial intelligence used for stress detection studies found from 2013 to 2023. Our review found 34 articles; not all the studies considered individuals with ASD or were out of the scope.
ARTICLE | doi:10.20944/preprints202307.0629.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Microalgae culture; Pigments; Absorption spectrum; Dunaliella; Anabaena
Online: 10 July 2023 (12:10:39 CEST)
(1) Background: Microalgae cultures are greatly facilitated if growers can easily and economically ascertain the quantitative and qualitative status of the culture continuously with satisfactory ac-curacy. (2) Methods: The locally isolated microalgae Dunaliella sp. and Anabaena sp. were cultured in small volumes with 2 intensities of white light (2000 and 8000 lux) and with green, blue and red light and the increase of their biomass and pigments was studied. Pigment analyses, continuous recordings of absorption spectra and calibration curves were performed. (3) Results: The intensity of 8000 lux white light yielded the highest increase in biomass, chlorophylls and carotenoids in Dunaliella sp. while 2000 lux and green light caused the greatest increase in biomass and phy-cocyanin in Anabaena sp. From the examination of the absorption spectra, the evolution of the pigment content can be estimated and both pigments and biomass are correlated very satisfactorily with the wavelength of 750 nm. (4) Conclusions: The use of absorption spectra as an easy, fast and economical method can be a useful tool for a good approximation of the state of the microalgae culture. This is clearly shown when the spectra of the culture under different lighting colors are compared which have a catalytic effect on the level of the pigments leading to the increase in carotenoids and phycocyanin of the green light.
ARTICLE | doi:10.20944/preprints202301.0393.v1
Subject: Computer Science And Mathematics, Analysis Keywords: Pseudo-prime spectrum; Zariski topology; spectral hyperspace
Online: 23 January 2023 (02:25:32 CET)
In this study, we define the concept of pseudo-prime subhypermodules of hypermodules as a generalization of the prime hyperideal of commutative hyperrings in . Firstly we examine the spectrum of the Zariski topology, which we built on the element of the pseudo-prime subhypermodules of a class of hyper-modules, then we give some relevant properties of the hypermodule in this topological hyperspace.
REVIEW | doi:10.20944/preprints202206.0212.v1
Subject: Social Sciences, Language And Linguistics Keywords: pitch perception; autism spectrum disorder; meta-analysis
Online: 15 June 2022 (05:41:36 CEST)
Purpose: Pitch plays an important role in auditory perception of music and language. This study provides a systematic review with meta-analysis to investigate whether individuals with autism spectrum disorder (ASD) have enhanced pitch processing ability and identify the potential factors associated with processing differences between ASD and neurotypicals. Method: We conducted a systematic search through six major electronic databases focusing on the studies that used nonspeech stimuli to provide a qualitative and quantitative assessment across existing studies on pitch perception in autism. We identified potential participant- and methodology-related moderators and conducted meta-regression analyses using mixed-effects models. Results: On the basis of 22 studies with a total of 464 participants with ASD, we obtained a small-to-medium positive effect size (0.26) in support of enhanced pitch perception in ASD.Moreover, the mean age and non-verbal IQ of participants were found to significantly moderate the between-studies heterogeneity. Conclusion: Our study provides the first meta-analysis on auditory pitch perception in ASD and demonstrates the existence of different developmental trajectories between individuals with ASD and neurotypicals. Non-verbal ability can be a significant contributor to the lower-level/ local processing bias in ASD. We highlight the need for further investigation of pitch perception in ASD under challenging listening conditions. Future neurophysiological and brain imaging research studies with a longitudinal design are also needed to better understand the nature of the atypical processing in ASD to obtain new insights into the underlying neural mechanisms and to help guide auditory-based interventions for improving language and social functioning.
ARTICLE | doi:10.20944/preprints202201.0296.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: microbiome; autism spectrum disorders; CRISPR-Cas; protospacer
Online: 20 January 2022 (10:28:07 CET)
Human gut microbiome is associated with various diseases, including autism spectrum disorders (ASD). Variations of the taxonomical composition in the gut microbiome of children with ASD have been observed repeatedly. However, features and parameters of the CRISPR-Cas systems in the gut microbiome of children with ASD have not been investigated yet. Here we demonstrate such an analysis in comparison with the healthy microbiome. For the identification of CRISPR-Cas systems, we used a combination of the publicly available tools suited for completed genomes with subsequent filtrations. In all considered datasets, the microbiomes of children with ASD contained fewer arrays per Gb of assembly, than the control group, but the arrays included more spacers on average. These patterns were observed systematically in our datasets, although their statistical significance hardly matched the thresholds. CRISPR arrays from the microbiomes of children with ASD differed from the control group neither in the fractions of spacers with protospacers from known genomes, nor in the sets of known bacteriophages providing protospacers. The majority of bacterial protospacers of the gut microbiome systems for both children with ASD and the healthy ones was located in the prophage islands.
REVIEW | doi:10.20944/preprints202110.0232.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: twice exceptionality; autism spectrum disorder; neuroimaging; MRI
Online: 15 October 2021 (16:17:13 CEST)
There is a long-standing association between exceptional cognitive abilities, of various sorts, and neuropsychiatric illness, but it has historically largely been investigated in an exploratory and non-systematic way. One group in which this association has been investigated with more rigor is in subjects who have been identified as twice exceptional; an educational term describing subjects who are both gifted and diagnosed with a neuropsychiatric disability. This term covers multiple conditions, but is of specific interest in particular in the study of autism spectrum disorder. Recent findings have led to the development of a hypothesis that a certain degree of the neurobiology associated with autism might even be advantageous for individuals and could lead to high giftedness, while becoming disadvantageous, once a certain threshold is surpassed. In this model, the same neurobiological mechanisms confer an increasing advantage up to a certain threshold, but become pathological past that point. Twice-exceptional individuals would be exactly at the inflection point, being highly gifted, but also symptomatic at the same time. Here, we review how existing neuroimaging literature on autism spectrum disorder can inform research on twice exceptionality specifically. We propose to study key neural networks with a robust implication in ASD to identify the neurobiology underlying twice-exceptionality. A better understanding of the neural mechanisms of twice exceptionality should help to better understand resilience and vulnerability to neurodevelopmental disorders and tofurther support affected individuals.
ARTICLE | doi:10.20944/preprints202101.0529.v1
Subject: Engineering, Automotive Engineering Keywords: radio frequency; microwave; spectrum analyzer; integrated; photonic
Online: 26 January 2021 (09:57:01 CET)
We report an all-optical radio-frequency (RF) spectrum analyzer with a bandwidth greater than 5 terahertz (THz), based on a 50-cm long spiral waveguide in a CMOS-compatible high-index doped silica platform. By carefully mapping out the dispersion profile of the waveguides for different thicknesses, we identify the optimal design to achieve near zero dispersion in the C-band. To demonstrate the capability of the RF spectrum analyzer, we measure the optical output of a femtosecond fiber laser with an ultrafast optical RF spectrum in the terahertz regime.
Subject: Social Sciences, Cognitive Science Keywords: amplitude spectrum; image statistics; complexity; aesthetics; phase
Online: 23 October 2020 (20:47:00 CEST)
Within the spectrum of a natural image, the amplitude of modulation decreases with spatial frequency. The speed of such an amplitude decrease, or the amplitude spectrum slope, of an image affects the perceived aesthetic value. Additionally, a human observer would consider a symmetric image more appealing than they do an asymmetric one. We investigated how these two factors jointly affect aesthetic preferences by manipulating both the amplitude spectrum slope and the symmetric level of images to assess their effects on aesthetic preference on a 6-point Likert scale. Our results showed that the preference ratings increased with the symmetry level but had an inverted U-shape relation to amplitude spectrum slope. In addition, a strong interaction existed between symmetry level and amplitude spectrum slope on preference rating, in that symmetry can amplify the amplitude spectrum slope’s effects. Such effects can be described by a quadratic function of the spectrum slope. That is, preference is an inverted U-shape function of spectrum slope whose intercept is determined by the number of symmetry axis. In addition, the interaction between the two factors is manifested as the modulation depth of the quadratic function.
ARTICLE | doi:10.20944/preprints202006.0271.v1
Subject: Social Sciences, Behavior Sciences Keywords: ERPs; Autism Spectrum Quotient; face perception; emotion
Online: 21 June 2020 (14:04:53 CEST)
This study explored the electrocortical correlates of conscious and nonconscious perceptions of emotionally laden faces in neurotypical adult women with varying levels of autistic-like traits (Autism Spectrum Quotient - AQ). Event-related potentials (ERPs) were recorded during the viewing of backward-masked images for happy, neutral, and sad faces presented either below (16 ms - subliminal) or above the level of visual conscious awareness (167 ms - supraliminal). Sad compared to happy faces elicited larger frontal-central N1, N2, and occipital P3 waves. We observed larger N1 amplitudes to sad faces than to happy and neutral faces in High-AQ (but not Low-AQ) scorers. Additionally, High-AQ scorers had a relatively larger P3 at the occipital region to sad faces. Regardless of the AQ score, subliminal perceived emotional faces elicited shorter N1, N2, and P3 latencies than supraliminal faces. Happy and sad faces had shorter N170 latency in the supraliminal than subliminal condition. High-AQ participants had a longer N1 latency over the occipital region than Low-AQ ones. In Low-AQ individuals (but not in High-AQ ones), emotional recognition with female faces produced a longer N170 latency than with male faces. N4 latency was shorter to female faces than male faces. These findings are discussed in view of their clinical implications and extension to autism.
ARTICLE | doi:10.20944/preprints201906.0168.v1
Subject: Physical Sciences, Optics And Photonics Keywords: optical antenna; radiation pattern; transmission spectrum; reconfiguration
Online: 18 June 2019 (05:52:29 CEST)
We propose a novel plasmon nano-optical antenna that consists of three vertically superimposed discs with different materials. Two symmetrical nanometer-scale Yagi antenna elements with gold-material are embedded into the surface of the middle disc with silicon dioxide. Based on plasmon theory and Yagi antenna principle, we explore the properties of the far-field radiation and near-field transmission of the antenna in near infrared band. It is found that the pattern of the xoy plane in the antenna can be adjusted in arbitrary direction. The far-field pattern and near-field transmission spectrum can be reconfigured by changing the angle a of the Yagi antenna elements in the middle disc. Moreover, we also discuss the influences of the widths and lengths of the elements on the near-field transmission spectrum when a is fixed at 0 degree.
ARTICLE | doi:10.20944/preprints202311.1008.v1
Subject: Public Health And Healthcare, Nursing Keywords: autism spectrum disorder; fatigue; parents; social support; spirituality
Online: 15 November 2023 (13:47:07 CET)
The high demands of caring for and raising a child with autism spectrum disorder on a daily basis fatally lead parents to the appearance of physical and mental fatigue. This study aimed to assess the effect of social support and spirituality on the fatigue of parents with children with autistic spectrum disorder. A cross-sectional study with a convenience sample was conducted in Schools of Special Education in Attica (Greece). The sample consisted of 123 parents who completed The Fatigue Assessment Scale (FAS), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Functional Assessment of Chronic Illness Therapy Spiritual Well-Being Scale (FACIT Sp-12) to measure the levels of fatigue, social support, and spirituality, respectively. Demographic data were, also, recorded. Data analysis was applied using IBM SPSS 21.0. The mean age was 47.3 years old, 81.3% were women, and 38.9% stated much / very much religious. The mean of total FAS was 28.4 (SD±7.5), of total FACIT Sp-12 was 31.5 (SD±8.7), and of total MSPSS 5.1 (SD±1.1). Higher levels of total MSPSS and FACIT Sp-12 were associated with lower total FAS (r= -0.50, p <0.001 and r= -0.49, p<0.001 respectively). Social support and spirituality are significant predictors of fatigue.
ARTICLE | doi:10.20944/preprints202310.1947.v1
Subject: Physical Sciences, Atomic And Molecular Physics Keywords: Cold atom; Ramsey spectrum; virtual instrument; sequential control
Online: 31 October 2023 (04:30:41 CET)
In this paper, a study was conducted on the Ramsey interference and spectral line locking techniques based on rubidium-87 cold atoms. Using sequential control technique, the timing design of a three-dimensional magneto-optical trap (MOT), cold atoms’ free fall, Ramsey microwave interference, and two-level fluorescence detection was realized, achieving the state preparation of cold atoms and clock transitions. By designing an automatic peak-finding algorithm, numerical integration was performed on the time-of-flying (TOF) signal, and narrow linewidth cold atom Ramsey interference fringes were obtained. Based on this, a frequency-hopping method was used to lock the frequency of the 10MHz oven-controlled crystal oscillator (OCXO) in a closed loop, achieving a linewidth of 38Hz. This preliminary result verifies the feasibility of the system design.
ARTICLE | doi:10.20944/preprints202309.1498.v1
Subject: Biology And Life Sciences, Other Keywords: Floristic composition; Biological Spectrum; Sultan Khail Valley; Pakistan
Online: 22 September 2023 (08:32:26 CEST)
The present study was conducted to explore the floristic composition, life form, and leaf size spectrum of vegetation, seasonality, and habitat condition of the Sultan Khail valley, Hindu Kush range, Pakistan. Regular trips were arranged during 2017–2019 to collect plant specimens and prepare a checklist of the flora of the area. The life form and leaf size spectrum of vegetation were determined. The plant species were also classified based on their habitat. The area is home to 332 species belonging to 234 genera and 96 families. Asteraceae (32 species) was the dominant family in the area, followed by Rosaceae (28 species) and Lamiaceae (21 species). Therophytes were found to be dominant in the area, followed by phanerophytes, while microphylls were the dominant leaf size class, followed by nanophylls. Seasonal variation in life forms showed that the spring, autumn, and winter seasons' flora was dominated by phanerophytes, while therophytes were dominant in the summer season. Seasonal variation in leaf size spectra showed that microphylls were dominant in the spring and summer, while in the autumn and winter seasons, nanophylls were dominant. The highest numbers of species were found in dry places, followed by forests. The flora of the study area is diverse. The habitat condition of the area is dry. The area's phytoclimate is thero-phanerophytic. The flora of the area is subjected to severe anthropogenic stress and needs proper conservation.
CASE REPORT | doi:10.20944/preprints202308.1404.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: molar pregnancy; cervical pregnancy; placenta accreta spectrum; hysterectomy
Online: 21 August 2023 (10:37:19 CEST)
Background: Coexisting monozygotic twin molar pregnancies with a living second fetus are known in the literature, with various outcomes and treatment options. Methods: Clinical praesentation of two separate throphoblastic diseases that became directly conditioned. Results: A 33-year-old nuliparous woman, after autolog insemination one blastocysts with extremely high MoM free BHCG, and in the 17th week of pregnancy, bled profusely where ultrasound found a dilated cervix filled with a mass similar to molar tissue with intact second gestational sac. The gynecologists decided on a laparotomy, so they performed a corporeal hysterotomy at the 19th week of pregnancy. A year later, the patient became pregnant spontaneously with an orderly course of pregnancy until the 30th week. Due to the acute abdomen, an emergency caesarean section is indicated, and after the laparotomy, 1000 mL of fresh blood and clots are found with a 5 cm zone of cicatricial percretism. A freshly dead male newborn 1530 g/ 44 cm, without the effect of the resuscitation procedure. With regard to cicatricial percretism, the gynecologist on duty decides on a supracervical hysterectomy.; Conclusions: The treatment approach to molar pregnancy that influenced the outcome of the second pregnancy and the overall poor reproductive outcome is discussed.
ARTICLE | doi:10.20944/preprints202307.2050.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Autism spectrum; neurodevelopmental disorder; refractive surgery; myopia; hyperopia
Online: 31 July 2023 (11:29:16 CEST)
Children with autism spectrum disorder (ASD) may have impaired vision from high refractive errors: near-sighted-myopia or far-sighted-hyperopia and aversion to spectacles or contact lenses. Refractive surgery can restore sharp vision and eliminate the need for spectacles or contact lenses. Restoration of sharp vision may improve ASD behaviors. Data were collated retrospectively for 267 children with refractive errors and neurodevelopmental disorders (NDD) diagnosed as ASD alone or NDD with ASD-like behaviors. Surgery was either laser photo-refractive keratectomy (PRK; 131 children), implantation of a phakic intra ocular lens (pIOL; 129 children) or removal of the crystalline lens and implantation of an IOL (refractive lens exchange, RLE; 21 children) under general anesthesia. Median age was 10.9 yrs. and median follow-up 3.1 yrs. Pre-operative refractive errors ranged from a mean +7.5 ± 0.9 D to -14.3. ± 4.8 D. Surgery corrected 87% to normal focal length (± 1 D). Visual acuity improved an average 0.6 logMAR. Social interactions and ASD behaviors improved in 55% (146/267) of the treated children (p < .01), including school performance; motor skills; depth perception; repetitive or stereotyped movements; anxiety/fear; and attention. Refractive surgery improves both visual function and behaviors in the majority of highly near-sighted or far-sighted children with ASD.
ARTICLE | doi:10.20944/preprints202307.1069.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: pregnancy; photoplethysmography; harmonic analysis; pulse wave analysis; spectrum
Online: 17 July 2023 (07:23:02 CEST)
Background: During pregnancy, major physiological changes occur in every system. Understanding the hemodynamic changes in different stages of pregnancy can help to identify abnormal states during pregnancy. Harmonic analysis could be a useful tool in monitoring the state of the ventricular-arterial system during pregnancy. The aim of this study was to investigate the specific statistical relationships between changes in harmonic indices during different stages of pregnancy. Methods: A Total of 380 women (190 pregnant women and 190 age-matched non-pregnant women), with ages ranging from 20 to 45, were enrolled in the study. The visit measured the subject’s hemodynamic parameters including heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP) and photoplethysmography (PPG). SBP and DBP were evaluated by an automatic blood pressure monitor. PPG signal were continuously recorded for 12-seconds using a PPG sensor. Spectrum analysis of the PPG signal was performed to evaluate the first five harmonic components (C1 – C5) and harmonic phases (P1 – P5). Result: A comparison between pregnant women and non-pregnant women showed that the non-pregnant women had lower DBP, C3, C5 and P5 (p<0.05). Waist Circumference, Heart rate, C2, C4 and P2 were higher in pregnant women. Logistic regression analysis was used to determine the associations between pregnancy and harmonics indices. C2, C4 and P3 were positively and P1 and P4 were negatively associated with pregnancy after controlling age, BMI, waist circumference, heart rate, SBP and DBP. Conclusion: The results of this study provide information on the changes in the harmonic frequency components during various stages of pregnancy. The harmonic components of the PPG signal have independent predictive value for changes in a woman's physiology during pregnancy. Since non-invasive PPG measurements can be performed frequently and easily, in the future, it is possible that the hemodynamic changes from some pregnancy-related disorders could be studied by harmonic analysis.
ARTICLE | doi:10.20944/preprints202307.0875.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: autism spectrum disorder; food selectivity; sensory sensitivity; children
Online: 17 July 2023 (07:20:51 CEST)
Autism spectrum disorders (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by food selectivity in a significant portion of the population. The nature of this selectivity remains unclear, with hypotheses suggesting associations with sensory disorders or stereotypical and repetitive patterns of activity and interests. This study aimed to determine the prevalence and nature of food selectivity traits in individuals with ASD compared to the neurotypical population. The study involved 219 participants, with 115 diagnosed with autism and 92 without. 12 children undergoing diagnosis were excluded from the analyses. Findings revealed that food selectivity traits are more common in individuals with ASD, with differences in preferences mainly involving structure, color, taste, and serving method. Children with ASD had more food selectivity traits than those without, and certain food characteristics could alter intake as they grow. Selectivity occurred for both sensory and stereotypical reasons, but stereotypical features significantly differentiated neurotypical individuals from those with ASD.
REVIEW | doi:10.20944/preprints202007.0328.v3
Subject: Biology And Life Sciences, Other Keywords: Evolution; Speciation; Crossbreeding; Hybridization; Species spectrum; Polyploidization; Somatic cell hybridization; Mutation
Online: 3 March 2022 (10:25:51 CET)
Although Darwin‘s evolutionary mutation theory has been widely accepted, many endeavors have been tried to challenge it. With more and more observation of successful hybridization and hybrids, the sexual isolation between species has become vague. The mechanism of evolution has been expanded from the classical model of evolution to multiple routes of speciation. Furthermore, a fundamental crossbreeding theory has been raised and proved by two lines of evidences: paleopolyploidy and fan-shaped spectrum of species. Ancient genome duplications are widespread throughout eukaryotic lineages, particularly in plants. The genome polyploidization, especially in the somatic cell hybridization, can break through the sexual incompatibility between diploid counterparts to hybridize and produce new species. By comparing characteristics, all species in every taxon, both in the extinct fossil and extant organisms, can be arranged into fan-shaped spectrum according to their similarity: left primitive type-middle advanced type-right primitive type. The species are primitive at the two ends and advanced at the middle. The primitive two species always resemble two types of more primitive species that can be confirmed as their ancestors respectively, and the middle species is half similar to the two ancestors respectively. These suggest that the species in the spectrum come from two different ancestors by crossbreeding and gene combination. As a sum, advanced species originated from crossbreeding of two primitive ancestors, by major method of polyploidization, and proved by results of fan-shaped spectrum of species. Then, sex is the cause, force and opportunity for evolution.
ARTICLE | doi:10.20944/preprints202104.0340.v1
Subject: Social Sciences, Psychology Keywords: savouring; affect; anxiety; mothers; autism spectrum disorder; ASD
Online: 13 April 2021 (10:22:26 CEST)
Savouring is an emotion regulation strategy and intervention that focuses on the process of attending, intensifying and prolonging positive experiences and positive affect associated with these memories. Personal savouring involves a reflection on positive memories that are specific to the individual and do not involve others. In contrast, relational savouring entails reflecting on instances when people were responsive to the needs of their significant others. Such interventions hold potential to benefit parents of children with autism spectrum disorder (ASD). Mothers of children with ASD tend to experience higher anxiety, lower positive affect (PA) and more negative affect (NA) compared to mothers of neurotypical children, leading to a diminished overall well-being. Moreover, ASD has multiplied by up to four times in the recent decade. Thus, this paper investigates whether savouring may enhance the overall well-being of mothers of young children with ASD by increasing positive affect and decreasing negative affect. 52 mothers of neurotypical children and 26 mothers of children with ASD aged 3-7 years old were given a series of questionnaires and randomly assigned to either relational savouring or personal savouring conditions. In relational savouring, mothers were asked to reflect upon a shared positive experience with their child while in the personal savouring condition, a personal positive experience was recalled. Across mothers of children with ASD and neurotypical children, findings suggest that savouring leads to a decrease in NA (p < .01) but not increases in PA. Similarly, mothers with higher levels of anxiety experience a greater decrease in NA (p < .001) compared to mothers with lower levels of anxiety post-savouring. This study proposes that a brief savouring intervention may be effective among mothers of preschoolers. As lower levels of negative affect is linked to healthier psychological well-being, mothers might be able to engage in more effective and warm parenting after savouring exercises, which would cultivate positive mother-child relationships that benefit their children in the long-term.
ARTICLE | doi:10.20944/preprints202103.0156.v1
Subject: Social Sciences, Psychology Keywords: Mindfulness; Autism Spectrum Disorders; Parental Stress; Parent Anxiety
Online: 4 March 2021 (12:26:04 CET)
This study aims to develop a clinical trial to test the efficacy of a Mindfulness Based Stress Re-duction (MBSR) and Self Compassion (SC) Program on self-reported values of anxiety, depres-sion, and stress in parents of children with Autism Spectrum Disorder (ASD) in primary school, in order to assess their integration into the framework of community intervention programs in Spain. Methods: A brief 8-week training program using Mindfulness based intervention (MBSR) and self-compassion (SC) has been applied to ten parents from the Valencian ASD parents’. Partici-pants were assigned to two groups, both groups received the same treatment but at two different measurement moments. Depression, Anxiety, Stress, Satisfaction with Life and Mindful Atten-tion Awareness measurements were assessed, in all participants, in three testing moments. Results: Analysis of Variance results suggested that MBSR and SC training reduces stress and anxiety and increases Mindful Attention Awareness. No significant changes were found in Life Satisfaction measurements. Conclusions: The small number of participants prevents us from generalising the results found. More MBSR and SC clinical trials are needed in parents of ASD with results on anxiety, depression and stress in order to demonstrate the relevance of the inclusion of these programmes in community-based early intervention services.
REVIEW | doi:10.20944/preprints202103.0067.v1
Subject: Social Sciences, Psychology Keywords: Autism Spectrum Disorders; Diagnostic Tools; Sex; Differential Diagnostic.
Online: 2 March 2021 (10:05:57 CET)
Studies on the prevalence of Autism Spectrum Disorders show a gender disproportion. In the last years, there has been an increasing interest in the search for an explanation. There are two main lines of research; the first one looks for sex-related biological reasons that justifies the low prevalence of ASD in women (some protective factor related to hormones or immune system among others), and the second line of studies is related to the possible biases introduced in the diagnostic tools or procedures. In this article, a review of the latter line of research is made. Theoretical analysis following two objectives: a) Analysis of possible biases in diagnostic tools and b) Other non-biological explanations for gender differences in the prevalence of ASD. The literature analyzed provides contradictory results although it evidences the possible bias both in the construction of the diagnostic tools and in the assessment and determination of their standards. It is necessary to develop specific or complementary tools and diagnostic procedures differentiated by gender in order to control for this bias.
ARTICLE | doi:10.20944/preprints202003.0437.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: antivirals; broad-spectrum; CRISPR; Cas9; SARS; COVID-19
Online: 8 January 2021 (13:53:55 CET)
All RNA viruses deliver their genomes into target host cells through processes distinct from normal trafficking of cellular RNA transcripts. The delivery of viral RNA into most cells hence triggers innate antiviral defenses that recognize viral RNA as foreign. In turn, viruses have evolved mechanisms to subvert these defenses, allowing them to thrive in target cells. Therefore, drugs activating defense to exogenous RNA could serve as broad-spectrum antiviral drugs. Here we show that transcriptional signatures associated with cellular responses to the delivery of a non-viral exogenous RNA sequence into human cells predict small molecules with broad-spectrum antiviral activity. In particular, transcriptional responses to the delivery of Cas9 mRNA into human hematopoietic stem and progenitor cells (HSPCs) highly matches those triggered by small molecules with broad-spectrum antiviral activity such as emetine, homoharringtonine, pyrvinium pamoate and anisomycin, indicating that these drugs are potentially active against other RNA viruses. Furthermore, these drugs have been approved for other indications and could thereby be repurposed to novel viruses. We propose that the antiviral activity of these drugs to SARS-CoV-2 should therefore be determined as they have been shown as active against other coronaviruses including SARS-CoV-1 and MERS-CoV. Indeed, two of these drugs- emetine and homoharringtonine- were independently shown to inhibit SARS-CoV-2 as this article was in preparation. These drugs could also be explored as potential adjuvants to COVID-19 vaccines in development due to their potential effect on the innate antiviral defenses that could bolster adaptive immunity when delivered alongside vaccine antigens.
ARTICLE | doi:10.20944/preprints202007.0433.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: DFT calculations; unfolding band structure; optical spectrum; KCl
Online: 19 July 2020 (20:22:08 CEST)
The unfolded band structure and optical properties of Cu-doped KCl crystals were computed by first principles within the framework of density functional theory, implemented in the ABINIT electronic structure package utilizing pseudopotential approximation and a plane-wave basis set. From a theoretical point of view, Cu substitution into pristine KCl crystals requires calculation by the supercell (SC) method. This procedure shrinks the Brillouin zone, resulting in a folded band structure that is difficult to interpret. To solve this problem and gain insight into the effect of copper ions (Cu+) on electronic properties, the band structure of SC KCl:Cu was unfolded to make a direct comparison with the band structure of the primitive cell (PC) of pristine KCl. To understand the effect of Cu substitution on optical absorption, we calculated the imaginary part of the dielectric function of KCl:Cu through a sum-over-states formalism and broke it down into different band contributions by partially making an iterated cumulative sum (ICS) of selected valence and conduction bands. Consequently, we identified those interband transitions that give rise to the absorption peaks due to the Cu+ ion. These transitions involve valence and conduction bands formed by the Cu-3d and Cu-4s electronic states
ARTICLE | doi:10.20944/preprints201903.0018.v1
Subject: Physical Sciences, Optics And Photonics Keywords: Fast Forward Model, Infrared, Emissivity Spectrum, Satellite, Validation
Online: 4 March 2019 (08:42:15 CET)
Timely processing of observations from hyper-spectral imagers, such as SEVIRI (Spinning Enhanced Visible and Infrared Imager), largely depends on fast radiative transfer calculations. This paper mostly concerns the development and implementation of a new forward model for SEVIRI to be applied to real time processing of infrared radiances for the physical retrieval of surface temperature and emissivity. The new radiative transfer model improves computational time by a factor of ≈ 7 compared to the previous versions and makes it possible to process SEVIRI data at nearly real time. The new forward model has been applied for the simultaneous retrieval of surface temperature and emissivity in three infrared channels (8.7, 10.8, 12 μm). The inverse scheme relies on a Kalman filter approach, which allows us to exploit a sequential processing of SEVIRI observations. Based on the new forward model, the paper also presents a validation retrieval performed with in situ observations acquired during a field experiment carried out in 2017 at Gobabeb (Namib desert) validation station. Furthermore, a comparison with IASI (Infrared Atmospheric Sounder Interferometer) emissivity retrievals has been performed as well. It has been found that the retrieved emissivities are in good agreement with each other and with in situ observations, i.e. average differences are generally well below 0.01.
ARTICLE | doi:10.20944/preprints201808.0447.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: intelligent radio networks; spectrum sharing; coexistence; experimental evaluation
Online: 27 August 2018 (10:17:38 CEST)
The explosive emergence of wireless technologies and standards, covering licensed and unlicensed spectrum bands has triggered the appearance of a huge amount of wireless technologies, with many of them coexisting in the same band. Unfortunately, the wireless spectrum is a scarce resource, and the available frequency bands will not scale with the foreseen demand for new capacity. Certain parts of the spectrum, in particular the license-free ISM bands, are overcrowded, while other parts, mostly licensed bands, may be significantly underutilized. As such, there is a need to introduce more advanced techniques to access and share the wireless medium, either to improve the coordination within a given band, or to explore the possibilities of intelligently using unused spectrum in underutilized (licensed) bands. Therefore, in this paper, we present a SDR based framework that can be employed to devise disruptive techniques to optimize the sub-optimal use of radio spectrum that exists today. Additionally, we describe two use cases for the proposed framework.
ARTICLE | doi:10.20944/preprints202310.0844.v1
Subject: Engineering, Civil Engineering Keywords: soil anisotropy; ground motion characteristics; standard design response spectrum
Online: 13 October 2023 (08:31:13 CEST)
Soil transverse isotropy results in different stiffness characteristics in the horizontal and vertical directions. However, the effect is usually neglected in the seismic motion analysis. In this study, an equivalent linear anisotropic soil model was established based on the finite element method and investigated the impact of anisotropic parameters on ground motion at the site under various seismic wave inputs. It is found that the anisotropic parameters have a more significant effect for the seismic waves with the dominant frequency closer to the fundamental frequency of the site. As an example, the soil dynamic parameters in Shanghai Yangshan Port were calibrated by a series of bending elements, resonance columns, and cyclic triaxial tests. The influences of anisotropy on the peak ground acceleration (PGA) and response spectrum are studied for Yangshan Port. Addi-tionally, the standard design response spectra considering the soil anisotropy were provided. A comparison reveals that the existing isotropic design response spectrum may lead to dangerous seismic design for the structures at Yangshan port.
ARTICLE | doi:10.20944/preprints202310.0167.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Developmental Coordination Disorder; DCD; Genetics; Movement Disorders; Pathogenetic Spectrum.
Online: 4 October 2023 (07:48:17 CEST)
Developmental Coordination Disorder (DCD) is a neurodevelopmental condition characterized by non-progressive central motor impairments. Mild movement disorder features have been observed in DCD. Until now, the etiology of DCD remains unclear. Recent studies suggested a genetic substrate in some patients with DCD, but comprehensive knowledge about associated genes and underlying pathogenetic mechanisms is still lacking. In this study, we first identified genes described in literature in patients with a diagnosis of DCD according to the official diagnostic criteria. Second, we exposed the underlying pathogenetic mechanisms of DCD, by investigating tissue- and temporal gene expression patterns and brain-specific biological mech-anisms. Third, we explored putative shared pathogenetic mechanisms between DCD and frequent movement disorders with a known genetic component, including ataxia, chorea, dystonia, and myoclonus. We identified 12 genes associated with DCD in literature, which are ubiquitously expressed in the central nervous system throughout brain development. These genes are involved in cellular processes, neural signaling and nervous system development. There was a remarkable overlap (62%) in pathogenetic mechanisms between DCD-associated genes and genes linked with movement disorders. Our findings suggest that some patients might have a genetic etiology of DCD, which could be considered part of a pathogenetic movement disorder spectrum.
ARTICLE | doi:10.20944/preprints202308.1002.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: autism spectrum disorder; diagnostic yield; DNA sequencing; novel disorders
Online: 14 August 2023 (09:36:37 CEST)
Autism spectrum disorder (ASD) is a common condition with lifelong implications and a strong hereditary component suggesting genetic underpinnings. The last decade has seen dramatic improvements in DNA sequencing, bioinformatics, and databases. We analyzed the raw DNA sequencing files on the Variantyx® (Framingham, MA, USA) bioinformatics platform for the last 50 autism patients evaluated with trio whole genome sequencing (trio-WGS). “Qualified” variants were defined as coding, very rare, and evolutionarily conserved. Primary Diagnostic Variants (PDV) additionally were in genes directly linked to ASD. A PDV was identified in 34/50 (68%) of cases, including 25 (50%) heterozygous de novo, 3 X-linked, 4 autosomal recessive, 2 autosomal dominant, and 1 heteroplasmic mtDNA variants. De novo variants in genes associated with ASD were far more likely to be Qualified than non-Qualified (control group, P = 0.002), validating that most are indeed disease causal. Only 14/34 (41%) of PDV cases had the variant listed on the laboratory report, and reanalysis increased diagnostic yield from 28% to 68%. The “missed” cases predominately included genes with zero (14 cases) to ≤5 prior reported case reports. Many cases both with and without a PDV had inherited Qualifying variants in known ASD-associated genes, suggesting polygenic inheritance. Thirty-three participants (66%) had treatment recommendation(s) based on DNA analyses. Our results demonstrate high yield of trio-WGS for revealing molecular diagnoses in ASD that is greatly enhanced by re-analyzing DNA sequencing files. Many are de novo and represent un/under-published conditions.
ARTICLE | doi:10.20944/preprints202308.0830.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: febrile seizure; autism spectrum disorder; CA2 region; inflammation; gliosis
Online: 10 August 2023 (10:44:26 CEST)
Febrile seizure (FS), which occurs as a response to fever, is the most common seizure that occurs in infants and young children. FS is usually accompanied by diverse neuropsychiatric symptoms including impaired social behaviors; however, no causative link between FS and autism spectrum disorder (ASD) has yet been established. Here, we provide evidence linking FS occurrence with ASD pathogenesis in rats. We developed an FS juvenile rats model and found ASD-like abnormal behaviors including deficits in social novelty, repetitive behaviors, and hyperlocomotion. In addition, FS model juvenile rats showed enhanced levels of gliosis and inflammation in the hippocampal CA2 region and cerebellum. Furthermore, abnormal levels of social and repetitive behaviors persisted in adults FS model rats. These findings suggest that occurrence of FS in infants can cause behavioral endophenotypes of ASD.
ARTICLE | doi:10.20944/preprints202306.1817.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: Language and communication; sex/gender; Autism Spectrum Disorder; children
Online: 26 June 2023 (13:54:32 CEST)
Sex/gender (S/G) differences in ASD language profiles have been poorly investigated. The present study aims to explore whether male (M) and female (F) children with ASD and with normal non-verbal cognitive abilities differ in their linguistic profiles. A sample of 76 Italian children with ASD (range: 4.9 – 8 years), including 50 M and 26 F, was retrospectively recruited. Language profiles were analyzed using standardized tests for the evaluation of receptive and expressive vocabulary as well as grammar. Grammatical comprehension was the most impaired domain compared to the other language measures in both M and F children. Comparing language profiles between S/G, F showed significantly better scores than M in grammatical production (p=.002), and M showed better active negative sentences comprehension (p=.035). Moreover, comparing the language profiles between M and F with receptive disorder, F had significantly worse grammatical comprehension and better grammatical production than M. Even among children without receptive disorder, F had significantly higher grammatical production scores. The S/G differences in language profile, particularly better expressive language in F than M, can partially contribute to the delayed ASD diagnosis or underdiagnosis of F without intellectual disability. Finally, our results document the importance of accurately investigating both expressive and receptive abilities in children with ASD.
ARTICLE | doi:10.20944/preprints202306.1594.v1
Subject: Biology And Life Sciences, Aquatic Science Keywords: Keywords microalgae; pigments; Amphidinium; Isochrysis; Nephroselmis; Anabaena; absorption spectrum.
Online: 22 June 2023 (10:48:04 CEST)
(1) Background: Truing to find a fast and representative method for the approximate calculation of the culture density and the cell content of useful pigments, the examination of the absorption spectra of cultures of the dinoflagellate Amphidinium carterae, the haptophyte Isochrysis galbana, the chlorophyte Nephroselmis sp. and the filamentous cyanobacterium Anabaena sp. were chosen, as representative species of different taxa. (2) Methods: The experimental cultures were made in small volumes with the discontinuous method, under specific conditions each one and during the culture the absorption spectra, the density of the culture and the concentration in the pigments chlorophyll, total carotenoids and phycocyanin was recorded. (3) Results: The algal density can be quite precisely predicted as the regression equation of the correlation of the OD value of 750 nm drawn from each absorption spectrum and the measured algal biomass was very strong. The same applies also for the relevant correlations between OD 750 nm and the recorded pigments. (4) Conclusions: Absorption spectra of microalgal cultures can be an easy, low cost and non-invasive method to get the necessary information for predicting the right time to collect an ideal combination of maximum biomass and useful pigments, provided that the interpretation of the spectra is done considering that they are usefully applicable for that purpose in a case sensitive manner in terms of species and prevailing conditions.
ARTICLE | doi:10.20944/preprints202305.0535.v1
Subject: Computer Science And Mathematics, Robotics Keywords: Human-Robot Interaction; Autism Spectrum Disorder; User-Centered Design
Online: 8 May 2023 (11:57:31 CEST)
Children with Autism Spectrum Disorder have deficits in social interaction and expressing and understanding emotions. Many robots for children with ASD have been proposed. However, few studies were found about how to design a social robot for children with ASD. Studies reviewed employed non-experimental studies to evaluate a social robot, but the methodology to design a social robot is rare. This study proposes a design path for a social robot for emotional communi-cation for children with ASD, following User-Centered Design approach. This design path is ap-plied with a study case, evaluated with an expert group on psychologist, human-robot interaction, human-computer interaction, and parents of children with ASD. Results show than following the design path proposed to design a social robot to communication emotions for children ASD is favorable.
HYPOTHESIS | doi:10.20944/preprints202211.0407.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: Autism; autism spectrum disorder; autophagy; macrophage polarization; neurogenesis; taurine
Online: 22 November 2022 (05:46:47 CET)
Contemporary research has found that people with autism spectrum disorder (ASD) exhibit aberrant immunological function, with a shift toward increased cytokine production and unusual cell function. Microglia and astroglia were found to be significantly activated in immuno-cytochemical studies, and cytokine analysis revealed that the macrophage chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and transforming growth factor β-1 (TGFB-1), all generated in the neuroglia, constituted the most predominant cytokines in the brain. Taurine (2-aminoethanesulfonic acid) is a promising therapeutic molecule able to increase the activity of antioxidant enzymes and ATPase, which may be protective against aluminum-induced neurotoxicity. It can also stimulate neurogenesis, synaptogenesis, and reprogramming of proinflammatory M1 macrophage polarization by decreasing mitophagy (mitochondrial autophagy) and raising the expression of the markers of the anti-inflammatory and pro-healing M2 macrophages, such as macrophage mannose receptor (MMR, CD206) and IL-10, while lowering the expression of the M1 inflammatory factor genes. Taurine also induces autophagy, which is a mechanism that is impaired in microglia cells and is critically associated with the pathophysiology of the ASD. We hypothesize here that taurine could reprogram the metabolism of M1 macrophages that are overstimulated in the nervous system of people suffering from ASD, thereby decreasing the neuroinflammatory process, neuronal death, and improving cognitive functions. Therefore, we think that taurine can serve as an important lead for the development of novel drugs for the ASD treatment.
ARTICLE | doi:10.20944/preprints202103.0042.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: Modulus of elasticity; frequency spectrum; mic; Euler-Bernoulli equation
Online: 1 March 2021 (18:31:31 CET)
This paper presents the simplified and quick way to obtain an experimental measure of the modulus of elasticity(E) of a piece of metal rod using the Smartphone microphone and through the experimental configuration in mode of unsupport beam Euler-Bernoulli(E-B). To understand it, it is required to have knowledge about flexural vibration of E-B beams and to know the analysis of the spectogram of the audio signal. The methodology consists in measuring the flexural resonance frequency through an app installed on a Smartphone and using the E formula deduced from the E-B theoretical framework. The results of the experimental measurements have a discrepancy of less than 5% with respect to the factory value, for a carbon steel rod with circular cross section using the impact excitation technique. It describes the precision and accuracy of the experimental measurement. It is useful, because it helps to classify the materials in the Faculty of Engineering and it helps to make a more efficient quality control.
ARTICLE | doi:10.20944/preprints201906.0030.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: autism; autistic spectrum disorder; children; behavior; ultrasonography; prenatal; pregnancy
Online: 4 June 2019 (12:56:37 CEST)
For the past several decades, abdominal prenatal ultrasonography has been the most significant technology in obstetrics with a long-established application. However, the frequency, exposure time, thermal and cavitation exposure indices, and increased acoustic output of the ultrasonic waves may be harmful to the embryo/fetus and might increase susceptibility to Autism Spectrum Disorder (ASD). The increase in the prevalence of ASD is associated with an affluent ethnicity, high socioeconomic status, and high parental education where prenatal ultrasonography is readily available and affordable. Enhanced biophysical adverse effects may link the analogous increase in prenatal ultrasonography and autism, and prenatal ultrasonography may emerge as a risk factor for autism. Radiography usage provides historical evidence for this fact: the predominant past opinion was that exposure to X-rays during pregnancy caused no significant risk to a fetus. However, the association between X-ray exposure and childhood leukemia was only established 40 years after X-ray use began. This review focuses on excessive PUS usage and ASD development. Public Abstract Advancements in medical technology over the past several decades have made prenatal ultrasound more frequently accessible to expecting mothers during their pregnancy, especially for the affluent. A parallel development in health care is the increase in autism diagnoses (Autism Spectrum Disorder, or ASD) in children of affluent families. There is a general lack of studies of the impact of prenatal ultrasound on fetuses, especially around varying attributes such as frequency, duration of exposure, and thermal and cavitation indices. There is also a historical precedent set, where exposing fetuses to X-rays was not found to be harmful until it was linked to the development of childhood leukemia decades later. This paper seeks to establish a need to further study these attributes of prenatal ultrasound overuse and their possible impact on a developing fetus, with a special focus on the occurrence of Autism.
ARTICLE | doi:10.20944/preprints201801.0199.v1
Subject: Engineering, Civil Engineering Keywords: curved surface slider; elastic response spectrum; friction; optimization; sensitivity
Online: 22 January 2018 (10:33:23 CET)
The design of curved surface sliders (CSS) based on the elastic response spectrum is done by iteration to find the combination of friction coefficient and displacement capacity which satisfies the condition that the maximum horizontal CSS force is equal to the horizontal force of the structure. Although this CSS design is valid it does not necessarily minimize structural acceleration. This paper therefore describes the optimum CSS design for minimum structural acceleration. All valid CSS designs and the optimum CSS design are represented by their associated trajectory in the elastic response spectrum plane which visualizes the optimization problem. The results demonstrate that the optimum CSS design is not obtained at maximum tolerated effective damping ratio. The subsequent sensitivity analysis describes how much the structural acceleration increases if the actual friction coefficient of the real CSS deviates from its optimum design value. The analysis points out that the increase in structural acceleration is approximately one order of magnitude smaller than the deviation in friction. The sensitivity data may be used by structural engineer to determine tolerable deviations in friction coefficient which still results in acceptable structural accelerations.
REVIEW | doi:10.20944/preprints201712.0111.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: autism spectrum disorder; melatonin; fetal development; neuroprotection; circadian rhythm
Online: 17 December 2017 (08:41:18 CET)
Autism spectrum disorder (ASD) refers to the diverse range of neurodevelopmental disorders accompanying impairments in social interaction, difficulties in communication, and stereotyped or repetitive behaviors. Unlike the older term, autism, the newer term, ASD, better reflects the broad range of autistic symptoms and denotes a single diagnostic category of autism accompanied by numerous conditions. The pineal hormone melatonin is a well-known neuroprotectant and circadian entrainer. This hormone crosses the placenta and enters the fetal circulation, then conveys photoperiodic information to the fetus during pregnancy. These actions enable normal sleep patterns and circadian rhythms, followed by normal neurodevelopment. Melatonin also reduces oxidative stress, which is harmful to the central nervous system. Therefore, melatonin acts as a neuroprotectant and circadian entrainer, and may reduce the risk of neurodevelopmental disorders such as ASD.
ARTICLE | doi:10.20944/preprints201702.0030.v1
Subject: Physical Sciences, Optics And Photonics Keywords: optical spectrum analysis; optical sensors; optical filters; coherent optics
Online: 9 February 2017 (15:49:30 CET)
To achieve a narrow bandwidth optical filter with a wide swept range for new generation optical spectrum analysis (OSA), an optoelectronic equivalent narrowband filter (OENF) is investigated and a swept optical filter with bandwidth of several MHz and swept range of several ten nanometers is built using electric filters and a swept laser as local oscillator (LO). The principle of OENF is introduced and analysis of OENF system is presented. Two electric filters are optimized to be RBW filters for high and medium spectral resolution application. Both simulations and experiments are conducted to verify OENF principle and results show that power uncertainty is less than 1.2% and spectral resolution can reach 6 MHz. Then, a real-time wavelength calibration system consisting of HCN gas cell and FP etalon is proposed to guarantee a wavelength accuracy of ±0.4 pm at C-band and to reduce the influence of phase noise and nonlinear velocity of swept LO. Finally, experiments on OSA of actual spectra of various optical sensors using OENF system are conducted. Experimental results indicate that OENF system has an excellent capacity in analysis of fine spectrum structures.
REVIEW | doi:10.20944/preprints202310.1217.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Plant-derived substances; Epigenetic modifications; virus; Broad-spectrum anti-viral
Online: 19 October 2023 (10:10:55 CEST)
Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to its inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The previous COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances when vaccination is not accessible or in individuals with compromised immune systems, drugs can give additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds including anti-viral. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Epigenetic modifications in the genome can affect gene expression without altering DNA sequence. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses have recruited cellular epi transcriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we are exploring the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing modulation processes and anti-viral effects on DNA and RNA viruses, and addressing future research objectives in this rapidly emerging field.
ARTICLE | doi:10.20944/preprints202310.0961.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: Autism spectrum disorder,; psychiatry; sedation; benzodiazepines; behavioural management; emergency medicine
Online: 16 October 2023 (10:33:52 CEST)
Adult patients with Autism Spectrum Disorder (ASD) exhibit a range of behaviours that can be disruptive to the medical care of themselves and other patients and as a result, are at higher risk of being sedated. The aim of the present study was to determine whether patients with ASD presenting to hospital for acute psychiatric crises re-ceive more sedative medications compared to similar patients without ASD. 43 adult patients with a previous di-agnosis of ASD who were referred to the mental health team at a single, large emergency department in metro-politan Victoria over the year of 2021 were identified and matched with an equal number of controls within the same cohort. Sedative medications were converted to diazepam and chlorpromazine equivalent doses and com-pared using repeated measures T-tests. Patients with ASD received 5.1mg more diazepam-equivalent benzodiaz-epines on average compared to matched controls (95%CI: 0.41-9.71). This difference was statistically significant (T=2.20, df=42, p=0.034). There was no significance difference in chlorpromazine-equivalent antipsychotic doses. Clinicians should be aware of the higher dose of sedatives, and consider other means of behavioural management in these patients.
ARTICLE | doi:10.20944/preprints202309.1543.v1
Subject: Social Sciences, Education Keywords: quality physical education; spectrum of teaching styles; student-teacher relation
Online: 22 September 2023 (08:51:26 CEST)
The enhancement of physical and sports literacy in school setting are prerogatives and development aim for the physical education (PE) teachers. Therefore, as part of the teaching of motor activities, the proposal of motor tasks through different organizational modes (individual tasks, in pairs, in small groups, circuits, relay, paths, team games, etc.) is functional to the achievement of the educational objectives set in the didactic learning units. The present study aims to assess PE teachers’ perception about the use of teaching styles during curricular lessons. The sample involved a total of 83 PE teachers (M= 41, F= 42, main age= 43,74±10,76) divided according to years of service (0-4 = 36%, 5-10 = 34%, and over 10 = 30%) and academic training (ISEF= 44% and master’s degree= 56%). Teachers complete a digitalized version of a self-produced questionnaire to assess how many times they use each teaching styles during the last month. Results can be summarized as follows: (a) academic training is significantly associated with the command, inclusion, and guided-discovery styles in PE; (b) command and practice Styles are often used by PE teachers, regardless of years of service and academic training, and (c) guided discovery and convergent/divergent Discovery Styles are most frequently used by graduate teachers, regardless of years of service. The preliminary results of the analysis of PE teachers’ perception of teaching styles reveals the prevalence of the use of some styles over others, and this presuppose not only a different (but similar) teacher’s behavior, but also limits children’s way of learning a certain motor task. Future research and analysis will investigate the perception of different teaching styles according to seniority, school grade and academic training to design training courses for teachers adapted to children’s needs.
ARTICLE | doi:10.20944/preprints202309.1244.v1
Subject: Engineering, Civil Engineering Keywords: frequency spectrum; theoretical analysis; moving vehicle; vehicle velocity; turbulent crosswinds
Online: 19 September 2023 (08:17:19 CEST)
Wind loads have become one of the key influence factors for the running safety of vehicles and comfort of passengers. Investigation on the wind speed spectrum characteristics of a moving vehicle under turbulent crosswinds is of great influence. Expressions of the wind speed spectrum of a moving vehicle was obtained from the von Kármán spectrum based on Taylor’s frozen flow hypothesis. The influence factors, including the ratio of the vehicle speed to the wind speed and the wind yaw angle from 15° to 175°, were analyzed. The maximum value of the wind speed spectrum and the corresponding frequency were studied as well. The results show that the maximum values of the wind speed spectrum of the moving vehicle were larger than those of the static vehicle. The maximum value of the wind speed spectrum corresponding to the moving vehicle first increased and then decreased as the wind yaw angle increased. Some of the frequencies corresponding to the longitudinal wind speed spectrum values of the moving vehicles were smaller than those of the static vehicle. For moving vehicles, the frequency values corresponding to the maximum values of the longitudinal wind speed spectrum first increased and then decreased as the ratio of the vehicle speed to the wind speed and the wind yaw angle increased.
REVIEW | doi:10.20944/preprints202304.0753.v2
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Lead Toxicity; Autism Spectrum Disorder; Microbiota; Gut-Brain Axis; Probiotics
Online: 12 September 2023 (02:53:37 CEST)
Autism Spectrum Disorder (ASD), a neurodevelopmental disorder characterized by persistent deficits in social interaction and communication manifests in early childhood and is followed by restricted and stereotyped behaviors, interests or activities in adolescence and adulthood (DSM-V). Although genetics and environmental factors have been implicated, the exact causes of ASD have yet to be fully characterized. New evidence suggests that dysbiosis or perturbation in gut microbiota (GM) and exposure to lead (Pb) may play important roles in ASD etiology. Pb is a toxic heavy metal that has been linked to a wide range of negative health outcomes including anemia, encephalopathy, gastroenteric diseases and more importantly cognitive and behavioral problems inherent to ASD. Pb exposure can disrupt GM, which is essential for maintaining overall health. GM, consisting of trillions of microorganisms, has been shown to play a crucial role in the development of various physiological and psychological functions. GM interacts with the brain in a bidirectional manner referred to as “Gut-Brain Axis (GBA).” In this review, following a general overview of ASD and GM, the interaction of Pb with GM in the context of ASD is emphasized. Potential exploitation of this interaction for therapeutic purposes is also touched upon.
ARTICLE | doi:10.20944/preprints202305.0713.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Autism Spectrum Disorder, Biomarker, Electrocardiograms, Machine Learning, Heart rate variability.
Online: 10 May 2023 (08:42:42 CEST)
In recent years, there has been a rise in the prevalence of autism spectrum disorder (ASD). The diagnosis of ASD requires behavioral observation and standardized testing completed by highly trained experts. Early intervention for ASD can begin as early as 1-2 years of age, but ASD diagnoses are not typically made until ages 2-5 years, thus delaying the start of intervention. There is an urgent need for non-invasive biomarkers to detect ASD in infancy. While previous research using physiological recordings has focused on brain-based biomarkers of ASD, this study investigated the potential of electrocardiogram (ECG) recordings as an ASD biomarker in 3-6-month-old infants. We recorded heart activity of infants at typical and elevated familial likelihood for ASD during naturalistic interactions with objects and caregivers. After obtaining the ECG signals, features such as heart rate variability (HRV) and sympathetic and parasympathetic activities were extracted from them. Then we evaluated the effectiveness of multiple machine learning classifiers for the classification of ASD likelihood. Our findings support our hypothesis that infant ECG signals contain a significant amount of information about ASD familial likelihood. Among the various machine learning algorithms tested, XGBoost performed best according to sensitivity (0.76±0.12), f1-score (0.75±0.12), precision (0.79±0. 12), classification accuracy (0.77±0.12, p-value = 0.01) and AUC (0.76±0.12, p-value = 0.02). These results suggest that ECG signals contains relevant information about the likelihood of an infant to develop ASD. Future studies should consider the potential of information contained in ECG, and other indices of autonomic control, for the development of biomarkers of ASD in infancy.
ARTICLE | doi:10.20944/preprints202304.0922.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: data acquisition; Orbitrap mass spectrometry; spectrum analysis; FPGA; FFT analysis
Online: 25 April 2023 (10:29:05 CEST)
Orbitrap mass spectrometers have been widely used in environmental component analysis . This paper presents an enhanced data acquisition system for in-situ detection of Orbitrap mass spectrometry, which enables in-suit real-time signal processing and analysis for atmospheric molecules with small mass numbers.During previous space atmospheric explorations, quadrupole mass spectrometry (QMS) was usually utilized for analyzing isotopic compositions and complicated compounds in the mixture. However, the inevitable ion scattering and drift during mass transfer, as well as the QMS attenuator loss, result in a relatively lower signal-to-noise ratio of the produced mass spectrum. In recent years, a novel mass spectrometer, called an Orbitrap mass spectrometer, has been gradually accepted and used because of its non-destructive detection ability, high mass resolution, and accuracy. Nevertheless, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is preferred over the Orbitrap mass spectrometry for ground applications, especially for detecting low-mass components (e.g. below 50 atomic mass units) due to the former’s superior resolution. As the mass number decreases, the detection system demands a higher sampling and processing rate. Additionally, in ground-based scenarios, mass spectrometry analysis software on computers is often employed to analyze the signals. Therefore, in order to achieve in-situ detection of the space atmospheric environment using the Orbitrap mass spectrometer, this paper proposes a real-time signal acquisition and processing system for mass spectrometry analysis. The system comprises of signal conditioning circuits, analog-to-digital conversion circuits, programmable logic circuits, and related software. These components perform spectrum analysis and process the signal in real-time on hardware components, allowing for high-speed acquisition and analysis of the signals produced by the Orbitrap mass spectrometer.
REVIEW | doi:10.20944/preprints202202.0056.v1
Subject: Social Sciences, Psychology Keywords: virtual reality; autism spectrum disorder; education; intervention; childhood and adolescence
Online: 3 February 2022 (15:17:12 CET)
Virtual reality (VR) technology gains theoretical support from rehabilitation and pedagogical theories and offers a variety of capabilities in educational and interventional contexts with affordable products. VR is attracting increasing attention in the medical and healthcare industry as it provides fully interactive three-dimensional simulations of real-world settings and social situations, which are particularly suitable for cognitive and performance training including social and interaction skills. The worldwide rising trend in the prevalence of autism spectrum disorder calls for innovative and efficacious techniques for assessment and treatment. The article offers a summary of current perspectives and evidence-based applications of VR technology as an educational and intervention tool for individuals with autism spectrum disorder, with a primary focus on social communication including social functioning, emotion recognition, and speech and language. Technology- and design-related limitations as well as the disputes over the application of virtual reality to autism research and therapy are discussed and future directions of this emerging field are highlighted with regards to application expansion and improvement, technology enhancement, and the development of brain-based research and theoretical models.
ARTICLE | doi:10.20944/preprints202201.0034.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: autistic spectrum disorder, male to female ratio, biases, young women.
Online: 5 January 2022 (10:57:39 CET)
The ratio of males to females with ASD is generally quoted as 4:1 though it is believed that there are biases preventing females being diagnosed and that the true ratio is lower. These biases have not been clearly identified or quantified. Starting with a clinical dataset of 1711 children <18 years old four different methods were employed in an inductive study to identify and quantify the biases and calculate the proportion of females missed. A mathematical model was constructed to compare the findings with current published data. The true male to female ratio appears to be 3:4. Eighty per cent of females remain undiagnosed at age 18 which has serious consequences for the mental health of young women.
ARTICLE | doi:10.20944/preprints202103.0709.v1
Subject: Engineering, Automotive Engineering Keywords: non-orthogonal multiple access; priority-ordering; spectrum sharing; time-division
Online: 29 March 2021 (16:57:37 CEST)
Non-orthogonal multiple access (NOMA) has been investigated to support massive connectivity for Internet-of-things (IoT) networks. However, since most IoT devices suffer from limited power and decoding capabilities, it is not desirable to pair a large number of devices simultaneously, which encourages two-user NOMA grouping. Additionally, most existing techniques have not considered the diversity in the target QoS of IoT devices, which may lead to spectrum inefficiency. Few investigations have partially considered that issue by using an order-based power allocation (OPA) approach, where the power is allocated according to the order to the user's target throughput within a priority-based NOMA (PNOMA) group. However, this does not fully capture the effects of diversity in the values of the users' target throughputs. In this work, we handle both problems by considering a throughput-based power allocation (TPA) approach, that captures the QoS diversity, within a three-users PNOMA group as a compromise between spectral efficiency and complexity. Specifically, we investigate the performance of a time-division PNOMA (TD-PNOMA) scheme, where the transmission time is divided into two-time slots with two-users per PNOMA group. The performance of such TD-PNOMA is compared with a fully PNOMA (F-PNOMA) scheme, where the three users share the whole transmission time, in terms of the ergodic capacity under imperfect successive interference cancellation (SIC). The results reveal the superiority of TPA compared with OPA approach in both schemes, besides that the throughput of both schemes can outperform each other under imperfect SIC based on the transmit signal-to-noise ratio and the deployment scenarios.
ARTICLE | doi:10.20944/preprints202102.0113.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: ion beam; copper oxide; chromatic change; photoemission spectrum; beam viewer
Online: 3 February 2021 (10:38:45 CET)
The color of a thin copper oxide layer formed on a copper plate was transformed from reddish-brown into blue-purple by irradiation with 5 keV Ar+ ions to a fluence as low as 1 1015 Ar+ cm–2. In the unirradiated copper oxide layer, the copper valence state of Cu2+ as well as Cu+ and/or Cu0 was included as indicated by the presence of a shake-up satellite line in a photoemission spectrum. While for the irradiated one, the satellite line decreased in intensity, indicating that irradiation resulted in the reduction from Cu2+ to Cu+ and/or Cu0. Furthermore, nuclear reaction analysis using a 16O(d, p)17O reaction with 0.85 MeV deuterons revealed a significant loss of oxygen (51015 O atoms cm–2) in the irradiated layer. Thus, the chromatic change observed in the present work originated in the irradiation-induced reduction of a copper oxide.
ARTICLE | doi:10.20944/preprints202012.0561.v2
Subject: Chemistry And Materials Science, Biomaterials Keywords: polyethylene; blend; long-chain branch; thermorheological complexity; activation energy spectrum
Online: 22 January 2021 (13:06:37 CET)
Long-chain branched metallocene-catalyzed high-density polyethylenes (LCB-mHDPE) were solution blended to obtain blends with varying degrees of branching. A high molecular LCB-mHDPE was mixed with low molecular LCB-mHDPE are varying concentrations, whose rheological behavior is similar but whose molar mass and molar mass distribution is significantly different. Those blends were characterized rheologically to study the effects of concentration, molar mass distribution, and long-chain branching level of the low molecular LCB-mHDPE. Owing to the ultra-long relaxation times of the high molecular LCB-mHDPE, the blends started behaving clearly more long-chain branched than the base materials. The thermorheological complexity showed an apparent increase in the activation energies Ea determined from G’, G”, and especially δ. Ea(δ), which for LCB-mHDPE is a peak function, turned out to produce even more pronounced peaks than observed for regular LCB-mPE and also LCB-mPE with broader molar mass distribution. Thus, it is possible to estimate the molar mass distribution from the details of the thermorheological complexity.
REVIEW | doi:10.20944/preprints202011.0468.v1
Subject: Social Sciences, Psychology Keywords: Autism Spectrum Disorders; Early Intervention; Parent mediated intervention; Parental Training
Online: 18 November 2020 (11:04:07 CET)
The aim of this article is to analyze the evidence against the effectiveness of intervention programs based on the participation of parents of children with autism. To obtain the data, a systematic search was carried out in four databases (ProQuest-PsychArticles, ProQuest-ERIC, ProQuest-PubMed, and Scopus). These documents were refined under the inclusion/exclusion criteria and a total of 51 empirical studies were selected. They were classified, first, according to the function of the intervention objective and, later, by the methodology applied (19 studies based on comprehensive interventions, 11 focused on the nuclear symptoms of ASD, 12 focused on the promotion of positive parenting and 9 interactions focused on children play). Once all the documents have been analyzed, the evidence indicates scientific efficacy in most studies, mainly in those based on child development and the application of behavioral analysis principles. Also, the positive influence of parent participation in such programs was demonstrated.
TECHNICAL NOTE | doi:10.20944/preprints202004.0538.v1
Subject: Engineering, Control And Systems Engineering Keywords: CR-PNN; relation spectrum; system identification; system filters; transfer function
Online: 30 April 2020 (16:39:39 CEST)
We have presented a controllable and human-readable polynomial neural network (CR-PNN) that is the first human-readable neural network. One can imagine its influence on system identification. Subsequently, we developed a relation spectrum in a medical application, which is likely to stand alongside the Fourier spectrum. However, the system analysis methodology is incomplete in contrast to signal processing methodology. Here, we presented the system filters for the first time. In this paper, we used the simulation system to verify the availability of the system analysis methodology. The system analysis methodology showed great properties in system identification and filter. The contribution of this paper is the system analysis methodology: transform method (CR-PNN), relation spectrum, and system filter design.
ARTICLE | doi:10.20944/preprints202002.0212.v1
Subject: Social Sciences, Psychology Keywords: font; spatial periodicity; discomfort; reading speed; autocorrelation; Fourier amplitude spectrum
Online: 16 February 2020 (04:47:43 CET)
The speed with which text can be read is determined in part by the spatial regularity and similarity of vertical letter strokes as assessed by the height of the first peak in the horizontal autocorrelation of the text. The height of this peak was determined for two passages in 20 fonts. The peak was unaffected by the size of the text or its content but was influenced by the font design. Sans serif fonts usually had a lower peak than serif fonts because the presence of serifs resulted in a more even spacing of letter strokes. There were small effects of justification and font- dependent effects of font expansion and compression. The visual comfort of images can be estimated from the extent to which the Fourier amplitude spectrum conforms to 1/f. Students were asked to adjust iBooks to obtain their preferred settings of font and layout. The preference was predicted by the extent to which the Fourier amplitude spectrum approximated 1/f, which in turn was jointly affected by the design of the font, its weight and the ratio of x-height to line separation. The above algorithms can be usefully applied to any orthography to estimate likely speed and comfort of reading.
ARTICLE | doi:10.20944/preprints202002.0189.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: network monitoring; spectrum sharing; Wi-Fi tethering; sensing of misbehavior
Online: 14 February 2020 (04:54:35 CET)
Wi-Fi tethering using a mobile device (e.g., a smartphone or a tablet) as a hotspot for other devices has become a common practice. Despite the potential benefits of Wi-Fi tethering, the open source nature of mobile operating systems (e.g., Google Android) can be abused by a selfish device to manipulate channel-access parameters to gain an unfair advantage in throughput performance. This can cause serious performance problems within a well-planned Wi-Fi network due to an unauthorized selfish or misconfigured tethering device interfering with nearby well-planned access points (APs). In this paper, we demonstrate that the selfish behavior of a tethering node that adjusts the clear channel assessment (CCA) threshold has strong adverse effects in a multi-AP network, while providing the selfish node a high throughput gain. To mitigate this problem, we present a passive online detection scheme that identifies the network condition and detects selfish tethering nodes with high accuracy by exploiting the packet loss information of on-going transmissions. To the best of our knowledge, this is the first research to consider the problem of detecting a selfish tethering node in managed Wi-Fi networks.
REVIEW | doi:10.20944/preprints201910.0144.v6
Subject: Biology And Life Sciences, Virology Keywords: virus; antiviral drug; drug discovery; drug development; broad-spectrum antivirals
Online: 14 February 2020 (02:27:24 CET)
Viral diseases are one of the leading causes of morbidity and mortality in the world. Virus-specific vaccines and antiviral drugs are the most powerful tools to combat viral diseases. However, broad-spectrum antiviral agents (BSAAs, i.e. compounds targeting viruses belonging to two or more viral families) could provide additional protection of general population from emerging and re-emerging viral diseases reinforcing the arsenal of available antiviral options. Here, we reviewed discovery and development of BSAAs and summarized the information on 120 safe-in-man agents in freely accessible database (https://drugvirus.info/). Future and ongoing pre-clinical and clinical studies will increase the number of BSAAs, expand spectrum of their indications, and identify drug combinations for treatment of emerging and re-emerging viral infections as well as co-infections.
ARTICLE | doi:10.20944/preprints201909.0128.v1
Subject: Biology And Life Sciences, Virology Keywords: virus; broad-spectrum antiviral; antiviral agent; drug target; systems biology
Online: 12 September 2019 (08:55:23 CEST)
Viruses are the major causes of acute and chronic infectious diseases in the world. According to the World Health Organization, there is an urgent need for better control of viral diseases. Re-purposing existing antiviral agents from one viral disease to another could play a pivotal role in this process. Here we identified novel activities of obatoclax and emetine against herpes simplex virus type 2 (HSV-2), human immunodeficiency virus 1 (HIV-1), echovirus 1 (EV1), human metapneumovirus (HMPV) and Rift Valley fever virus (RVFV) in cell cultures. Moreover, we demonstrated novel activities of emetine against influenza A virus (FluAV), niclosamide against HSV-2, brequinar against HIV-1, and homoharringtonine against EV1. Our findings may expand the spectrum of indications of these safe-in-man agents and reinforce the arsenal of available antiviral therapeutics pending the results of further in vivo tests.
ARTICLE | doi:10.20944/preprints201812.0318.v1
Subject: Social Sciences, Behavior Sciences Keywords: Subjective sleep assessment; Autism spectrum disorder; REM sleep; NREM sleep
Online: 27 December 2018 (10:21:06 CET)
Sleep disturbances very common in children with autism. That is why it requires instruments that facilitate its evaluation. Goals: Perform the evaluation of sleep from a subjective prospect in a group of children with primary autism and compare to a control group, using the Sleep Habits in Children Survey (CSHQ), In order to determine sleep disturbances, according to the sub-scales results. Method: A prospective cross-sectional study of the sample was carried out. A group with primary Autism n = 21 was selected. For the assessment of the dream we chose (CSHQ). The differences between independent groups were calculated by applying a Mann Whitney U test (p <0.05). Results: The group of children with autism showed the highest values of the total scale (mean = 48.00) wish is congruent with a greate disfuntion of sleep, compared to the control group (mean = 36.47) for p = 0.00. Significant differences were found for all sub scales p = 0.00, with the exception of sub-scale number 7. Conclusions: There is a high presence of sleep disturbances in children with primary autism, which are related to multifactorial causes, with the exception of sleep breathing disorders that did not show statistically significant differences between groups.
ARTICLE | doi:10.20944/preprints201809.0560.v1
Subject: Physical Sciences, Atomic And Molecular Physics Keywords: Schrödinger equation; vibrational spectrum; collocation; inverse multiquadratic function; rectangular matrix
Online: 28 September 2018 (10:15:42 CEST)
We explore the use of inverse multiquadratic (IMQ) functions as basis functions when solving the vibrational Schrödinger equation with the rectangular collocation method. The quality of the vibrational spectrum of formaldehyde (in six dimensions) is compared to that obtained using Gaussian basis functions when using different numbers of width-optimized IMQ functions. The effects of the ratio of the number of collocation points to the number of basis functions and of the choice of the IMQ exponent are studied. We show that the IMQ basis can be used with parameters where the IMQ function is not integrable. We find that the quality of the spectrum with IMQ basis functions is somewhat lower that that with a Gaussian basis when the basis size is large and for a range of IMQ exponents. The IMQ functions are, however, advantageous when a small number of functions is used or with a small number of collocation points e.g. when using square collocation.
ARTICLE | doi:10.20944/preprints201806.0418.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: ice XIV; vibrational spectrum; hydrogen bond; CASTEP, first-principles; DFT
Online: 26 June 2018 (12:44:03 CEST)
It is always a difficult task to assign the peaks recorded from vibrational spectrum. Herein we explored a new pathway of density functional theory (DFT) simulation to present three kinds of spectra of ice XIV and can be referenced as inelastic neutron scattering (INS), IR, and Raman experimental spectrum. The INS spectrum is proportional to phonon density of states (PDOS) while the photon scattering signals reflect the normal vibration frequencies near the Brillouin zone (BZ) center. Based on good agreements with experimental data, we identified the relative frequency and made scientific assignments by normal vibration modes analysis. The debating two hydrogen bond (H-bond) peaks among ice phases from INS have been discussed and the dynamic process of H-bond vibrations were found to be classified into two basic modes. we deduce that two H-bond modes are a general rule among ice family and more works are ongoing to investigate this subject.
ARTICLE | doi:10.20944/preprints201805.0359.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: autism spectrum disorder; endocrine; estrogen; immune activation; melanin concentrating hormone
Online: 25 May 2018 (10:37:23 CEST)
The voluminous daily output of autism research has become increasingly disconnected, existing largely within highly specific subspecialty areas, and lacking cross-disciplinary linkages of context, theory, and findings to inform a unified body of knowledge. Robust syntheses of published research across the fields of psychiatry, cellular and molecular biology, neurology, endocrinology, immunology, behavioral and social sciences, and pedagogy may help clarify and extend current knowledge by guiding more efficient future research efforts investigating underlying causes, developmental divergences, novel treatments, and specific, sensitive biological markers in autism. This synthesis of interdisciplinary research indicates the hypothalamic-pituitary-adrenal (HPA) stress axis may be at the center of an interaction among sex steroids, immune function, signaling protein transcriptions, neurogenesis, and dysregulation of brain structures sending or receiving projections from the HPA stress axis. These interaction manifest observably as a range of sexually dimorphic behaviors and functional limitations often falling within the current diagnostic features of Autism Spectrum Disorder (ASD). The pathogenicity of endocrine dysregulation may serve as a valuable model for developing a cohesive theory of ASD by explaining how the HPA and connected brain areas respond to extreme conditions of dysregulated endocrine signaling to cause symptoms associated with autism.
REVIEW | doi:10.20944/preprints201703.0095.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: autism spectrum disorders; fragile X syndrome (FXS); sleep disorder; melatonin
Online: 15 March 2017 (07:40:49 CET)
Fragile X syndrome (FXS) is the most frequent monogenic form of autism spectrum disorder (ASD). Autistic FXS is caused by loss of the fmr1 gene product, the fragile X mental retardation protein (FMRP), triggering physiological and behavioral abnormalities. It is correlated with clock components for behavioral circadian rhythm. Mutation of this gene causes the disturbances in sleep patterns and circadian behavior commonly observed in patients with autistic FXS, accompanied by frequent dysregulation of melatonin synthesis and melatonin-dependent signaling. These changes impair vigilance, learning and memory, and are also linked to autistic behavior including the abnormal anxiety response. However, although several possible causes, symptoms, and clinical features of ASD have been investigated, the correlation between an altered circadian rhythm and autistic FXS has not been extensively studied. Recent works have highlighted the impact of melatonin on the nervous, immune, and metabolic systems. Even though utilization of melatonin for sleep disorder in ASD has been considered in clinical research, further studies should be aimed at its neuroprotective role in ASD during developmental period. In this review, we focus on the regulatory circuits involved in melatonin dysregulation and circadian system disruption in those with autistic FXS. Additionally, we discuss the neuroprotective effect of melatonin intervention. This may improve neuroplasticity and physical capability. We also review the underlying molecular mechanisms, and suggest that melatonin may be a useful novel treatment for autistic FXS, countering the adverse effects of circadian variation.
ARTICLE | doi:10.20944/preprints202309.1456.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: organic conductors; surface resistance derivative; resonances; oscillation spectrum; tilted magnetic field
Online: 21 September 2023 (12:02:46 CEST)
The resonance spectrum of surface resistance derivative in quasi-two dimensional layered organic conductors has been calculated numerically for the out-of-plane and in-plane magnetic field. Not all but some of the resonances in a given series of transitions are present in the spectra. They are observed at the positions corresponding to the maxima in the surface resistance derivative curve and are in a good agreement with previously calculated magnetic field resonance positions. For tilted magnetic fields, there are more resonances present in the spectrum than in the case of a non-tilted field. Apart from the resonances corresponding to the transitions between the adjacent surface states there also appear resonances involving the transitions between the more distant surface states. This is correlated with the specific topology of Fermi surface of the organic conductors. The presented calculations will allow correct interpretation of the experimental curves for the resonance spectrum, and also to obtain information on the surface properties of these materials for their possible implementation in fabrication of devices based on organic molecular conductors.
ARTICLE | doi:10.20944/preprints202309.1157.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Autism Spectrum Disorder; Deep learning; VGG16; Inception v3; ResNet50; DenseNet121; MobileNet
Online: 18 September 2023 (09:44:09 CEST)
Autism Spectrum Disorder (ASD) is a neuro developmental condition that impacts social interac-tion, communication, and behavior. It is called a spectrum because its symptoms and degrees of severity can vary greatly from one person to the next. Differentiations in brain structure and function have been observed between autistic and typically developing brains. Various aspects of brain function, including information processing, sensory perception, and the capacity to interpret and respond to social cues, may be affected by these differences. The signs and symptoms of ASD are readily apparent to parents in the first few years of their child’s life. The symptoms of ASD, it is said, first appear in early childhood and continue into maturity. Brain MRI analysis utilizing deep learning methods show encouraging findings in the study of ASD. In this study, we look at how well a customized VGG16 architecture compares models that have already been trained. Inception v3, ResNet50, DenseNet121, and MobileNet are used to identify and analyze ASD problems in a brain MRI dataset from people with ASD. The proposed methods have been vali-dated on the unlabeled ABIDE 1 dataset that is freely available to the public. After the unlabeled data has been clustered, five different Deep Learning (DL) methods are used and compared. The results are compared to those of other studies that have already been conducted.
REVIEW | doi:10.20944/preprints202308.2136.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: autism spectrum disorder; children; sleep apnea; sleep-disordered breathing; sleep quality
Online: 31 August 2023 (10:19:12 CEST)
Sleep-disordered breathing is a significant problem affecting the pediatric population. These conditions can affect sleep quality and significantly affect children's overall health and well-being. Difficulties in social interaction, communication, and repetitive behavioral patterns characterize autism spectrum disorder. Sleep disturbances are common in children with ASD. This literature review aims to gather and analyze available studies on the relationship between SDB and children with autism spectrum disorder. We comprehensively searched the literature using major search engines (PubMed, Scopus, and Web of Science). After removing duplicates, we extracted a total of 96 records. We selected 19 studies for inclusion after a thorough title and abstract screening process. A total of 7 articles were ultimately included. This review has analyzed the relationship between autism spectrum disorder and sleep-disordered breathing, particularly Obstructive Sleep Apnea, highlighting an intriguing web of complex associations. Some studies involving children have demonstrated a significant association between autism spectrum disorder and the presence of Obstructive Sleep Apnea. Furthermore, a heightened risk of developing sleep disturbances, including sleep-disordered breathing, has emerged in children with autism. The risk and prevalence of obesity are increasing in pediatric subjects with autism spectrum disorder. Obesity has been identified as a predictive factor for Sleep-disordered breathing, and Body Mass Index can directly correlate with Obstructive Sleep Apnea in these children. Adenotonsillectomy has proven to be pivotal in improving behavioral issues in autism spectrum disorder children with obstructive Sleep Apnea. In conclusion, this review underscores the complexity of the interplay between autism spectrum disorder and sleep-disordered breathing, emphasizing the importance of further research to understand underlying mechanisms and develop optimal therapeutic and preventative approaches to enhance sleep quality and overall health in children with autism spectrum disorder.
ARTICLE | doi:10.20944/preprints202307.1797.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: Sleep; Autism Spectrum Disorder; Quality of Life; Family Quality of Life
Online: 26 July 2023 (10:12:23 CEST)
Study Objectives: To (1) investigate the prevalence of sleep disorder symptoms in caregivers of children with autism spectrum disorder (ASD) and (2) the relationships between caregiver sleep problems and their health-related quality of life and family quality of life. Methods: Descriptive cross-sectional study of caregivers (N=62) of children ages 6 to 11 years old diagnosed with ASD receiving care at a regional autism research and resource center. Measurements and Results: Participants completed the Sleep Habits Questionnaire (SHQ), the Medical Outcomes Study (MOS) SF-12, and the Beach Center Family Quality of Life Scale (FQOL). Caregivers with longer sleep duration reported better mental health and better family quality of life. Caregivers who reported insomnia symptoms, non-restorative sleep, and insufficient sleep were more likely to report poorer mental health than caregivers who did not report these sleep disorder symptoms. Caregivers with obstructive sleep apnea and restless legs syndrome experienced worse physical quality of life. Conclusions: The physical and mental health of the primary caregiver is essential to the support of the child with ASD and to the functioning of the family. The study findings point to the importance of future research and interventions to enhance sleep health in order to improve quality of life for caregivers of children with ASD.
ARTICLE | doi:10.20944/preprints202307.1087.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Raman spectrum; Denoising; Variational mode decomposition; Empirical mode decomposition; Mode mixing
Online: 17 July 2023 (09:27:33 CEST)
As a fast and nondestructive spectroscopic analysis technique, Raman spectroscopy has been widely applied in chemistry. However, noise is usually unavoidable in Raman spectra. Hence, denoising is an important step before Raman spectral analysis. A novel spectral denoising method based on variational mode decomposition (VMD) was introduced to solve the above problem. The spectrum is decomposed into a series of modes (uk) by VMD. Then, the high frequency noise modes are removed and the remaining modes are reconstructed to obtain the denoised spectrum. The proposed method was verified by two artificial noised signals and two actual Raman spectra. As comparison, empirical mode decomposition (EMD), Savitzky-Golay (SG) smoothing and discrete wavelet transformation (DWT) are also investigated. At the same time, signal-to-noise ratio (SNR) was introduced as evaluation indicators to verify the performance of the proposed method. The results show that compared with EMD, VMD can significantly improve mode mixing and endpoint effect. Some information of the small sharp peak is lost after VMD denoising. However, VMD lost fewer information than that of EMD, SG smoothing and DWT. Moreover, the Raman spectrum by VMD denoising is more excellent than that of EMD, SG smoothing and DWT in terms of visualization and SNR. Therefore, VMD provides superior denoising capabilities for Raman spectra.
ARTICLE | doi:10.20944/preprints202305.1153.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: power line communication; modulation; spread spectrum; dc-dc converter; emi mitigation
Online: 16 May 2023 (10:38:05 CEST)
Interference on Power Line Communication (PLC), which is a wired communication technology that provides communication and data transmission over the existing electrical network, is examined in this paper. Many applications employ PLC technologies, which have the benefit of leveraging existing power connections for both power and data transfer, reducing cost and complexity. These interactions may be observed in contemporary smart grids and automobile power networks, where lengthy cables, switching power supplies, and communication links all work together but exacerbate electromagnetic interference problems. This research examines the effects of Spread Spectrum methods used to reduce EMI from power converters on PLC systems. Spread spectrum modulation and its three variants Sine, Random and Triangle are frequently employed to meet the requirements of electromagnetic compatibility, however there are some repercussions, that might be detrimental to the converter or the rest of the electrical network. These outcomes occur for various modulation algorithm settings and at various frequencies. Measurements are made utilising the Frame Error Rate value provided by the PLC link system to ascertain the interference produced by a SiC-based DC-DC converter in order to investigate these concerns and standardise an assessment approach.
ARTICLE | doi:10.20944/preprints202304.0692.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Emotion Recognition; smart bracelet; heart rate; wearable; Autism Spectrum Disorder (ASD)
Online: 21 April 2023 (08:38:45 CEST)
This paper presents a framework to recognize the affective state of children with Autism Spectrum Disorder (ASD) in an in-the-wild setting using Heart Rate (HR) information. Our algorithm classifies a child’s emotion into positive, negative, or neutral states by analyzing the heart rate signal. The HR signal is obtained from a smartwatch in real-time using our smartwatch application. The heart rate data is acquired when the child learns to code a robot while interacting with an avatar that assists the child in communications skills and programming the robot. In this paper, we also present a comparison of using HR data for the classification of emotions with classification based on features extracted from HR signals using Discrete Wavelet Transform (DWT). Our experimental results show that the proposed method produces a comparable performance with the state-of-the-art HR-based emotion recognition techniques, despite the fact that our experiments are performed in an uncontrolled setting as opposed to a lab environment. This work contributes to real-world affect analysis of children with ASD using HR information.
ARTICLE | doi:10.20944/preprints202301.0545.v1
Subject: Physical Sciences, Mathematical Physics Keywords: Energy polynomials; Energy spectrum; harmonic oscillator; orthogonal polynomials; tridiagonal matrix; wavefunction
Online: 30 January 2023 (07:09:26 CET)
We use a recently proposed formulation of quantum mechanics based, not on potential functions but rather, on orthogonal energy polynomials. In this context, the most important building block of a quantum mechanical system, which is the wavefunction at a given energy, is expressed as pointwise convergent series of square integrable functions in configuration space. The expansion coefficients of the series are orthogonal polynomials in the energy; they contain all physical information about the system. No reference is made at all to the usual potential function. We consider, in this new formulation, few representative problems at the level of undergraduate students who took at least two courses in quantum mechanics and are familiar with the basics of orthogonal polynomials. The objective is to demonstrate the viability of this formulation of quantum mechanics and its power in generating rich energy spectra illustrating the physical significance of these energy polynomials in the description of a quantum system. To assist students, partial solutions are given in an appendix as tables and figures.
ARTICLE | doi:10.20944/preprints202209.0331.v2
Subject: Physical Sciences, Mathematical Physics Keywords: Ramsey theory; complete graph; vibrational spectrum; eigenfrequency; selection rule; cyclic molecule; viscoelasticity; entropic elasticity
Online: 16 February 2023 (09:55:15 CET)
Ramsey theory influences the dynamics of mechanical systems, which may be described as abstract complete graphs. We address a mechanical system which is completely interconnected with the two kinds of ideal Hookean springs. The suggested system mechanically corresponds to the cyclic molecules, in which functional groups are interconnected with two kinds of chemical bonds, represented mechanically with two springs k1 and k2. In this paper, we consider a Cyclic system (molecule) built of six equal masses m and two kinds of springs. We pose the following question: what is the minimal number of masses in the such a system in which three masses are constrained to be connected with spring k1 or three masses to be connected with spring k2? The answer to this question is supplied by the Ramsey theory, and it is formally stated as follows: what is the minimal number R3,3? The result emerging from the Ramsey theory is R3,3=6. Thus, in the aforementioned interconnected mechanical system will be necessarily present the triangles (at least one triangle), built of masses and springs. This prediction constitutes the vibrational spectrum of the system. Thus, the Ramsey Theory supplies the selection rules for the vibrational spectra of the cyclic molecules. Symmetrical system built of six vibrating entities is addressed. The Ramsey approach works for 2D and 3D molecules, which may be described as abstract complete graphs. The extension of the proposed Ramsey approach to the systems, partially connected by ideal springs, viscoelastic systems and systems, in which elasticity is of an entropy nature is discussed. “Multi-color systems” built of three kinds of ideal springs are addressed. The notion of the inverse Ramsey network is introduced and analyzed.
COMMUNICATION | doi:10.20944/preprints202208.0039.v1
Subject: Biology And Life Sciences, Virology Keywords: Echovirus; enterovirus; broad-spectrum antiviral agent; antiviral drug combination; antiviral strategy
Online: 2 August 2022 (05:01:21 CEST)
Background: Enterovirus infections affect people around the world, causing a range of illnesses, from mild fevers to severe, potentially fatal conditions. There are no approved vaccines or treatments for enterovirus infections. Methods: We have tested our library of broad-spectrum antiviral agents (BSAs) against echovirus 1 (EV1) in human adenocarcinoma alveolar basal epithelial A549 cells. We also tested combinations of the most active compounds against EV1 in A549 and human immortalized retinal pigment epithelium RPE cells. Results: We confirmed anti-enteroviral activities of pleconaril, rupintrivir, cycloheximide, vemurafenib, remdesivir, emetine, and anisomycin and identified novel synergistic rupintrivir-vemurafenib, vemurafenib-pleconaril and rupintrivir-pleconaril combinations against EV1 infection. Conclusions: Because rupintrivir, vemurafenib, and pleconaril require lower concentrations to inhibit enterovirus replication in vitro when combined, their combinations may have fewer side effects in vivo and therefore should be further studied in pre- and clinical trials.
ARTICLE | doi:10.20944/preprints202108.0079.v1
Subject: Social Sciences, Psychology Keywords: autism; sleep; fetal alcohol spectrum disorders; nightmares; anxiety; executive function; behaviour
Online: 3 August 2021 (13:07:06 CEST)
Children with Fetal Alcohol Spectrum Disorders (FASD) and Autism Spectrum Disorders (ASD) experience significantly higher rates of sleep disturbances than their typically developing peers. Pre-sleep anxiety and waking emotional content is known to affect the content and frequency of nightmares, which can be distressing to children and caregivers. This is the first study to analyse nightmare frequency and content in FASD, and to assess its association with psychometric outcomes. We assessed reports from 277 caregivers of children with ASD (n=61), FASD (n=112), and TD children (n=104) using the Children’s Sleep Habits Questionnaire (CSHQ), the Child Behavior Checklist (CBCL), the Spence Children’s Anxiety Scale (SCAS) and the Behavior Rating Inventory for Executive Functioning (BRIEF). Within the ASD group, 40.3% of caregivers reported their children had nightmares. Within the FASD group, 73.62% of caregivers reported their children had nightmares and within the TD group, 21.36% of caregivers reported their children had nightmares. Correlation analysis revealed significant associations between anxiety and nightmares, maladaptive behaviour and nightmares, and executive functioning and nightmares in the TD and FASD groups, but not ASD group. This paper adds to the emerging body of work supporting the need for sleep interventions as part of clinical practice with regard to children with ASD and FASD. As a relatively niche but important area of study this warrants much needed further research.
ARTICLE | doi:10.20944/preprints202010.0272.v1
Subject: Social Sciences, Psychology Keywords: Gender Differences; Tic disorder; Selective Mutism; Trichotillomania; Autism Spectrum Disorder; Aggression
Online: 13 October 2020 (10:45:13 CEST)
Gender differences have been documented in the prevalence of psychological symptoms. Tic disorders and ASD are more common in male clinical samples, while selective mutism and trichotillomania are more common in female clinical samples. In a review of 84 published case studies of Japanese children, this study explores gender differences in the prevalence of four categories of symptoms and expressions made in therapy for tics, selective mutism, trichotillomania, and autism spectrum disorder (ASD). Case studies were evaluated using both qualitative coding and statistical analysis. The findings were mostly consistent with epidemiological surveys and empirical research on adults. The gender differences in symptom prevalence and their expression can be summarized as differences in more direct aggression for boys versus indirect aggression for girls. The objective and progress in the therapy are to control impulsive energy for boys and to express energy for girls.
ARTICLE | doi:10.20944/preprints202007.0171.v1
Subject: Computer Science And Mathematics, Computational Mathematics Keywords: energy cascade; modulational instability; Fourier power spectrum; Korteweg-de Vries equations
Online: 9 July 2020 (06:44:33 CEST)
In this study we investigate the formation of dynamical energy cascades in higher order KdV-type equations. In the beginning we recall what is known about the dynamic cascades for the classical KdV (quadratic) and mKdV (cubic) equations. Then, we investigate further the mKdV case by considering a richer set of initial perturbations in order to check the validity and persistence of various facts previously established for the narrow-banded perturbations. Afterwards we focus on higher order nonlinearities (quartic and quintic) which are found to be quite different in many respects from the mKdV equation. Throughout this study we consider both the direct and double energy cascades. It was found that the dynamic cascade is always formed, but its formation is not necessarily accompanied by the nonlinear stage of the modulational instability. Direct cascade structure remains invariant regardless the size of the spectral domain. In contrast, the double cascade shape can depend on the size of the spectral domain, even if the total number of cascading modes remains invariant. Results obtained in this study can be potentially applied to plasmas, free surface and internal wave hydrodynamics.
ARTICLE | doi:10.20944/preprints202003.0447.v1
Subject: Computer Science And Mathematics, Computational Mathematics Keywords: energy cascade; modulational instability; Fourier power spectrum; Korteweg-de Vries equations
Online: 31 March 2020 (09:46:20 CEST)
In this study, we investigate the formation of dynamical energy cascades in higher-order KdV-type equations. In the beginning, we recall what is known about the dynamic cascades for the classical KdV (quadratic) and mKdV (cubic) equations. Then, we investigate further the mKdV case by considering a richer set of initial perturbations in order to check the validity and persistence of various facts previously established for the narrow-banded perturbations. Afterwards, we focus on higher-order nonlinearities (quartic and quintic) which are found to be quite different in many respects from the mKdV equation. Throughout this study, we consider both the direct and double energy cascades. It was found that the dynamic cascade is always formed, but its formation is not necessarily accompanied by the nonlinear stage of the modulational instability. Direct cascade structure remains invariant regardless of the size of the spectral domain. In contrast, the double cascade shape can depend on the size of the spectral domain, even if the total number of cascading modes remains invariant. Results obtained in this study can be potentially applied to plasmas, free surface and internal wave hydrodynamics.
ARTICLE | doi:10.20944/preprints201810.0413.v3
Subject: Physical Sciences, Mathematical Physics Keywords: gravitational atom; quantum black hole; quantum levels; Schrodinger equation; mass spectrum
Online: 6 December 2019 (04:14:35 CET)
In this paper only one basic assumption has been made: if we try to describe black holes, their behavior should be understood in the same language as the one we use for particles; black holes should be treated just like atoms. They must be quantum forms of matter, moving in accordance with Schrödinger equations just like everything else. In particular, Rosen’s quantization approach to the gravitational collapse is applied in the simple case of a pressureless “star of dust” by finding the gravitational potential, the Schrödinger equation and the solution for the collapse’s energy levels. By applying the constraints for a Schwarzschild black hole (BH) and by using the concept of BH effective state, previously introduced by one of the authors (CC), the BH quantum gravitational potential, Schrödinger equation and the BH energy spectrum are found. Remarkably, such an energy spectrum is in agreement (in its absolute value) with the one which was conjectured by Bekenstein in 1974 and consistent with other ones in the literature. This approach also permits to find an interesting quantum representation of the Schwarzschild BH ground state at the Planck scale. Moreover, two fundamental issues about black hole quantum physics are addressed by this model: the area quantization and the singularity resolution. As regards the former, a result similar to the one obtained by Bekenstein, but with a different coefficient, has been found. About the latter, it is shown that the traditional classical singularity in the core of the Schwarzschild BH is replaced, in a full quantum treatment, by a two-particle system where the two components strongly interact with each other via a quantum gravitational potential. The two-particle system seems to be non-singular from the quantum point of view and is analogous to the hydrogen atom because it consists of a “nucleus” and an “electron”.
ARTICLE | doi:10.20944/preprints201910.0115.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: cognitive radios; Collaborative Intelligent Radio Networks; spectrum sharing; coexistence; experimental evaluation
Online: 10 October 2019 (09:37:08 CEST)
DARPA, the Defense Advanced Research Projects Agency from the United States, has started the Spectrum Collaboration Challenge with the aim to encourage research and development of coexistence and collaboration techniques of heterogeneous networks in the same wireless spectrum bands. Team SCATTER has been participating in the challenge since its beginning, back in 2016. SCATTER’s open-source software-defined physical layer (SCATTER PHY) has been developed as a standalone application, with the ability to communicate with higher layers of SCATTER’s system via ZeroMQ, and uses USRP X310 software-defined radio devices to send and receive wireless signals. SCATTER PHY relies on USRP’s ability to schedule timed commands, uses both physical interfaces of the radio devices, utilizes the radio’s internal FPGA board to implement custom high-performance filtering blocks in order to increase its spectral efficiency as well as enable reliable usage of neighboring spectrum bands. This paper describes the design and main features of SCATTER PHY and showcases the experiments performed to verify the achieved benefits.
COMMUNICATION | doi:10.20944/preprints201901.0284.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: tridiagonal representation; orthogonal polynomials; potential functions; asymptotics; recursion relation; spectrum formula
Online: 29 January 2019 (04:37:49 CET)
Using an algebraic method for solving the wave equation in quantum mechanics, we encountered a new class of orthogonal polynomials on the real line. One of these is a four-parameter polynomial with a discrete spectrum. Another that appeared while solving a Heun-type equation has a mix of continuous and discrete spectra. Based on these results and on our recent study of the solution space of an ordinary differential equation of the second kind with four singular points, we introduce a modification of the hypergeometric polynomials in the Askey scheme. Up to now, all of these polynomials are defined only by their three-term recursion relations and initial values. However, their other properties like the weight function, generating function, orthogonality, Rodrigues-type formula, etc. are yet to be derived analytically. This is an open problem in orthogonal polynomials.
ARTICLE | doi:10.20944/preprints201809.0547.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: ice X; vibrational spectrum; first-principles DFT; Raman scattering; IR absorption
Online: 27 September 2018 (13:25:06 CEST)
A typical vibrational spectrum in the ice phase has four separate bands: translation, libration, bending and stretching. Ice X, the final ice phase under high pressure, shows an exotic vibrational spectrum. Theoretically, an ideal crystal of ice X only has one peak at 998 cm-1 for Raman scattering and two peaks at 450 cm-1 and 1507 cm-1 for infrared absorption in this work. These three characteristic peaks are indicators of the phase transition between ice VII/VIII and ice X. Despite much experimental and theoretical work on ice X, only this study has clearly indicated these characteristic peaks in the region of the IR band. The phonon density of states shows quite different features than ice VIII, which could be verified by inelastic neutron scattering in the future. The dynamic processes of 15 vibrational normal modes are discussed and the typical hydrogen bonds are missing.
ARTICLE | doi:10.20944/preprints201809.0366.v1
Subject: Computer Science And Mathematics, Geometry And Topology Keywords: Pisot substitution tilings; pure point spectrum; regular model set; algebraic coincidence
Online: 19 September 2018 (07:44:07 CEST)
We consider Pisot family substitution tilings in $\R^d$ whose dynamical spectrum is pure point. There are two cut-and-project schemes(CPS) which arise naturally: one from the Pisot family property and the other from the pure point spectrum respectively. The first CPS has an internal space $\R^m$ for some integer $m \in \N$ defined from the Pisot family property, and the second CPS has an internal space $H$ which is an abstract space defined from the property of the pure point spectrum. However it is not known how these two CPS's are related. Here we provide a sufficient condition to make a connection between the two CPS's. In the case of Pisot unimodular substitution tiling in $\R$, the two CPS's turn out to be same due to [5, Remark 18.5].
ARTICLE | doi:10.20944/preprints201809.0175.v1
Subject: Engineering, Automotive Engineering Keywords: Metal-halide lamp, quartz-halogen lamp, blue LED, TFT-LCD, spectrum
Online: 10 September 2018 (14:20:19 CEST)
Light sources tend to affect images captured in any automatic optical inspection (AOI) system. In this study, the effectiveness of metal-halide lamps, quartz-halogen lamps, and LEDs as the light sources in AOI systems for the detection of the 3rd and 4th layers electrodes of thin-film-transistor liquid crystal displays (TFT-LCDs) is examined experimentally. The results show that the performance of LEDs is generally comparable or better than that of metal-halide and quartz-halogen lamps. The best optical performance is by the blue LED due to its spectrum compatibility with the time-delay-integration charged-coupled device (TDI CCD) sensor and its better spatial resolution. The images revealed by the blue LED are sharper and more distinctive. Since current LEDs are more energy efficient and environmentally friendly, using LEDs as the light source for AOI is very beneficial. As the blue LED performs the best, it should be adopted for AOI using TDI CCD sensors.
ARTICLE | doi:10.20944/preprints201804.0148.v1
Subject: Physical Sciences, Acoustics Keywords: modal wave-number spectrum; match mode; horizontal line array; moving source
Online: 11 April 2018 (12:42:57 CEST)
In this study, a matched-mode autoregressive source depth estimation method (MMAR) based on autoregressive (AR) wavenumber estimation is proposed for a moving source in shallow water waveguides. The signal original frequency and the environmental parameters, namely, the sound speed profile and bottom properties are known as a prior knowledge. The mode wavenumbers are estimated by the AR modal wavenumber spectrum. On the basis of the mode wavenumber estimation, the mode amplitudes can be estimated by the wavenumber spectrum that is obtained by generalized Hankel transform. The source depth estimation is determined by the peak of source depth function wherein the data mode best matches the replica mode that is calculated using a propagation model. Compared with other methods of moving source depth estimation, the proposed method exhibits a better performance in source depth estimation under low signal-to-noise ratio or the small range span. The selection of horizontal line array depth is illustrated by simulation and normal mode theory in details.
ARTICLE | doi:10.20944/preprints201610.0032.v1
Subject: Computer Science And Mathematics, Computer Networks And Communications Keywords: internet of thing; IoT; cognitive sensor networks; forwarding; spectrum-availability; retransmission
Online: 10 October 2016 (12:17:22 CEST)
The widespread proliferation of sensor nodes in the era of Internet of Things (IoT) coupled with increasing usage of wireless spectrums especially the ISM band makes it difficult to deploy real-life IoT. Currently, the cognitive radio technology enables sensor nodes communicate with each other through the licensed spectrum bands as well as the free ISM bands. Cognitive radio networks (CRSNs) are considered as a promising solution to the problem of spectrum under utilization and artificial radio spectrum scarcity. The paradigm of dynamic spectrum access allows secondary users (SUs) to utilize wireless spectrum resources which belong to primary users (PUs) with minimal interference to PUs. Due to the dynamic spectrum availability and quality, routing for SUs in multi-hop CRSNs is a challenge. In this paper, we introduce novel routing metrics that estimate both the future spectrum availability and the average transmission time with the consideration of both the global statistical spectrum usage and local instant spectrum resources. In our novel routing metrics, one retransmission is allowed and considered to reduce the probability of rerouting upon PU's arrival. Then, we propose two routing algorithms for multi-hop CRSNs. Finally, we conduct simulations, whose results show that our proposed algorithms lead to a significant performance improvement over the reference algorithm.
ARTICLE | doi:10.20944/preprints202102.0586.v1
Subject: Engineering, Control And Systems Engineering Keywords: nonlinear spectrum distortions; signal exposition time; fiber Bragg grating; fiber Bragg sensors; fiber optic sensors; fiber optic interrogator; optical spectrum analyzer; charge-coupled device elements; CCD
Online: 25 February 2021 (13:50:46 CET)
Abstract: Nonlinear spectrum distortions are caused by the peculiarities of the operation of charge-coupled device elements (CCD), in which the signal exposition time (TINT) is one of the significant parameters. A change of TINT on a CCD leads to a nonlinear distortion of the resulting spectrum. Nonlinear distortion of the spectrum, in its turn, leads to errors in determining the central wavelength of Fiber Bragg Gratings (FBG) and spectrally sensitive sensors, which, in general, negatively affects the accuracy of measuring systems. The paper proposes an algorithm for correcting nonlinear distortions of the spectrum obtained on a spectrum analyzer using CCD as a receiver. It is shown that preliminary calibration of the optical spectrum analyzer with subsequent mathematical processing of the signal makes it possible to make corrections in the resulting spectrum, thereby leveling the errors caused by measurements at different TINT.
ARTICLE | doi:10.20944/preprints202310.0144.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: autism spectrum disorders; applied behavior analysis; parent training; joint attention; video modelling
Online: 3 October 2023 (10:35:14 CEST)
Social communication skills, especially eye contact and joint attention, are highly impaired in autism spectrum disorder (ASD) and predict functional outcomes. Applied Behavior Analysis is one of the best evidence-based treatments for ASD, but it is not accessible to most families in low- and middle-income countries (LMICs) as it is a costly and intensive and needs to be delivered by highly specialized professionals. Parental training has emerged as an effective alternative. The aim of this study was to test the efficacy of a parental intervention group via video modeling to acquire eye contact and joint attention. Four graded measures of eye contact and joint attention (full physical prompt, partial physical prompt, gestural prompt, and independent) were assessed in 34 children with ASD and intellectual disability (ID). There was a progressive reduction in the level of prompt required over time to acquire eye contact and joint attention, and a positive correlation between the time of exposure to the intervention and acquisition of the abilities. This parent training using video modelling to teach eye contact and joint attention skills to children with ASD and ID is a low-cost intervention that can be applied in low- resource settings.
ARTICLE | doi:10.20944/preprints202308.1625.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Autism spectrum disorders (ASD); antibiotics; penicillin; tetracycline; microbiome; gut-brain axis (GBA)
Online: 23 August 2023 (07:15:02 CEST)
Abstract: Autism spectrum disorders (ASDs) are complex, lifelong, neurodevelopmental conditions of largely unknown cause. The global prevalence of autism has increased twentyfold to thirtyfold since the earliest epidemiologic studies were conducted in the late 1960s and early 1970s. Recent reports agree on the association of ASD with the alteration of the microbiome (dysbiosis), which raises the possible role of external factors. Our study aimed at identifying antibiotic classes that might be associated with the development of ASD-related dysbiosis either promoting or inhibiting the process. Statistical comparison was made between the average yearly consumption of different antibiotic classes (1997-2020) and the number of individuals living with ASD estimated for 2023/100000 population in 30 European countries and the results were statistically analyzed. Tetracycline (J01A) showed significant positive (promoting) association with the prevalence of ASD (Pearson r: 0.373, p: 0.043. OR: 1.312, CI95%: 0.995-1.791, p: 0.065) and narrow-spectrum, beta-lactamase resistant penicillin (J01CF) (Pearson r: 0.524, p: 0.003, OR: 3.240, CI95%: 1.710-8.853, p: 0.004, Kruskal-Wallis p: 0.032). Mild, negative (inhibitory) association was observed with broad-spectrum, beta-lactamase sensitive penicillin (J01CA) (Pearson r: -0.278, p: 0.157, OR: 0.808, CI95%: 0649-0957, p: 0.028) and narrow-spectrum, beta-lactamase-sensitive penicillin (J01CE) (Pearson p: -0.032, r: 0.865, OR: 0.725, CI95%: 0.543-0.885, p: 0,009). Our findings strongly support the animal experiments when penicillin-exposed newborn mice developed "autism-like" behavior.
ARTICLE | doi:10.20944/preprints202307.1710.v1
Subject: Engineering, Mining And Mineral Processing Keywords: spodumene, combined collector, flotation, surface tension measurement, Zeta potential, infrared spectrum analysis
Online: 26 July 2023 (11:27:39 CEST)
The mechanism of anionic/cationic combination collector ST-8 for the efficient separation of spodumene and feldspar was investigated by flotation tests, surface tension measurements, zeta potential measurements and infrared spectroscopy analysis. The flotation results indicated that when the optimum molar combination of sodium oleate and dodecylamine was 6:1-10:1 and pH=8.5 or so, the recovery of spodumene reached a maximum of 80% and that of feldspar reached about 24.5%. Zeta potential measurements showed that the negative shift of the kinetic potential on the surface of spodumene was much stronger than that on the surface of feldspar, indicating that the adsorption capacity of the combined collector on spodumene surface and feldspar surface was greatly different. From the surface tension as well as the synergistic parameters, there was a strong mutual attraction between dodecylamine and sodium oleate, and there was a significant synergistic effect between them. Infrared spectroscopy indicated that the combined collector chemisorbed on the mineral surface, and the intensity of the absorption peak after the action of spodumene was much stronger than that after the action of feldspar. The solution chemistry of the combined collector revealed that at pH 8.5, the positively charged ions RNH3+ and (RNH3+)22+ in dodecylamine and the negatively charged RCOO- and (RCOO-)22- ions in oleic acid form highly reactive complexes to interact with the mineral surface by electrostatic gravitation, thus achieving efficient separation of spodumene and feldspar. Finally, from the closed circuit test results, a flotation index of 6.34% Li2O grade and 88.51% Li2O recovery was obtained.
REVIEW | doi:10.20944/preprints202306.1033.v3
Subject: Medicine And Pharmacology, Complementary And Alternative Medicine Keywords: Autism Spectrum Disorder (ASD); microbiota; epigallocatechin-3-gallate (EGCG); inflammation; oxidative stress
Online: 20 July 2023 (07:02:00 CEST)
Autism Spectrum Disorder (ASD) is characterized by varying degrees of difficulty in social interaction and communication. These deficits are often associated with gastrointestinal symptoms, indicating alterations in both intestinal microbiota composition and metabolic activities. The intestinal microbiota influences the function and development of the nervous system. In individuals with ASD, there is an increase in bacterial genera such as Clostridium, as well as species involved in the synthesis of branched-chain amino acids (BCAA) like Prevotella copri. Conversely, decreased amounts of Akkermansia muciniphila, and Bifidobacterium spp. are observed. Epigallocatechin gallate (EGCG) is one of the polyphenols with the greatest beneficial activity on microbial growth and its consumption is associated with reduced psychological distress. Therefore, the objective of this review is to analyze how EGCG and its metabolites can improve the microbial dysbiosis present in ASD and its impact on the pathology. The analysis reveals that EGCG inhibits the growth of pathogenic bacteria like Clostridium perfringens and Clostridium difficile. Moreover, it increases the abundance of Bifidobacterium spp. and Akkermansia spp. As a result, EGCG demonstrates efficacy in increasing the production of metabolites involved in maintaining epithelial integrity and improving brain function. This identifies EGCG as highly promising for complementary treatment in ASD.