ARTICLE | doi:10.20944/preprints201805.0211.v1
Subject: Biology, Anatomy & Morphology Keywords: gap junction; connexin; annular gap junction vesicle; mitochondria; lysosome
Online: 15 May 2018 (08:39:33 CEST)
It is becoming clear that in addition to gap junctions, playing a role in cell-cell communication, gap junction proteins, connexins, located in cytoplasmic-compartments may have other important functions. Mitochondrial connexin 43 (Cx43) is increased after ischemic preconditioning and has been suggested to play a protective role in the heart. How Cx43 traffics to the mitochondria and the interactions of mitochondria with other Cx43-containing structures are unknown. In this study, immunocytochemical, super-resolution and transmission electron microscopy were used to detect cytoplasmic Cx43-containing structure and to demonstrate their interactions with other cytoplasmic organelles. The most prominent cytoplasmic Cx43-containing structures, annular gap junctions, were demonstrated to form intimate associations with lysosomes as well as with mitochondria. Surprisingly, the frequency of associations between mitochondria and annular gap junctions was greater than that between lysosomes and annular gap junctions. The benefits of annular gap junction/mitochondrial associations are not known. However, it is tempting to suggest that the contact between annular gap junction vesicles and mitochondria facilitates Cx43 deliver to the mitochondria. Furthermore, it points to the need for investigating trafficking of Cx43 to cytoplasmic compartments and annular gap junction as more than only a vesicle destined for degradation.
REVIEW | doi:10.20944/preprints201812.0333.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: gap junction; connexin; angiogenesis; cell mechanics; cell migration; cellular stiffness
Online: 28 December 2018 (05:19:52 CET)
Angiogenesis, the sprout and growth of new blood vessels from existing vasculature, is an important process of tumor development for the supply of oxygen and nutrition to cancer cells. Endothelial cell is a critical player in angiogenic process by modulating cell proliferation, cell motility, and cell morphology in the response to pro-angiogenic factors and environments provided by tumor and cancer cells. Recent in vivo and in vitro studies have revealed that gap junction of endothelial cells also participates in the promotion of angiogenesis. Pro-angiogenic factors modulate gap junction function and connexins expression in endothelial cells, whereas endothelial connexins involve in angiogenic tube formation and cell migration of endothelial cells via both gap junction channel function dependent or independent mechanisms. In particular, connexin might have the potential to regulate cell mechanics such as cell morphology, cell migration, and cellular stiffness that are dynamically changed during angiogenic processes. Here, we review the implication for endothelial gap junction and cellular mechanics in vascular angiogenesis.
ARTICLE | doi:10.20944/preprints201902.0109.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: connexins; Cx43; gap junctions; lung cancer; immunohistochemistry; prognosis; nuclear
Online: 13 February 2019 (10:30:49 CET)
Direct intercellular communication, mediated by gap junctions formed by the connexin transmembrane protein family, is frequently dysregulated in cancer. Connexins have been described as tumour suppressors, but emerging evidence suggests that they can also act as tumour promoters. This feature is connexin- and tissue-specific and may be mediated by complex signalling pathways through gap junctions or hemichannels or by completely junction-independent events. Lung cancer is the number one cancer in terms of mortality worldwide, and novel biomarkers and therapeutic targets are urgently needed. Our objective was to gain a better understanding of connexins in this setting. We used several in silico tools to analyse TCGA data in order to compare connexin mRNA expression between healthy lung tissue and lung tumours and correlated these results with gene methylation patterns. Using Kaplan-Meier plotter tools, we analysed a microarray dataset and an RNA-seq dataset of non-small cell lung tumours in order to correlate connexin expression with patient prognosis. We found that connexin mRNA expression is frequently either upregulated or downregulated in lung tumours. This correlated with both good and poor prognosis (overall survival) in a clear connexin isoform-dependent manner. These associations were strongly influenced by the histological subtype (adenocarcinoma versus squamous cell carcinoma). We present an overview of all connexins but particularly focus on four isoforms implicated in lung cancer: Cx26, Cx30.3, Cx32 and Cx43. We further analysed the protein expression and localization of Cx43 in a series of 72 human lung tumours. We identified a subset of tumours that exhibited a unique strong nuclear Cx43 expression pattern that predicted worse overall survival (p=0.014). Upon sub-stratification, the prognostic value remained highly significant in the adenocarcinoma subtype (p=0.002) but not in the squamous carcinoma subtype (p=0.578). This finding highlights the importance of analysis of connexin expression at the protein level, particularly the subcellular localization. Elucidation of the underlying pathways regulating Cx43 localization may provide for novel therapeutic opportunities.
ARTICLE | doi:10.20944/preprints201808.0238.v1
Subject: Engineering, Construction Keywords: building information modelling (BIM); mixed reality; energy performance gap; knowhow gap; prefab buildings
Online: 14 August 2018 (03:52:39 CEST)
At present European buildings typically consume two to five times more energy than predicted at the design stage. An important cause of this performance gap is the discrepancies between the design specification and the As-Built condition. Such discrepancies are mainly due to the gaps in knowhow between design, production and construction professionals. Design is more and more contained into a virtual environment and loses touch with the physical production and construction sites. As the construction sector enters the Industry 4.0 era, Building Information Modelling (BIM) based Mixed Reality can intertwine virtual and real worlds to bridge the knowhow gaps.
ARTICLE | doi:10.20944/preprints202206.0313.v1
Online: 22 June 2022 (10:02:33 CEST)
In the sugar industry, dextran generates difficulties in the manufacturing process. Crude dextranase (EC 184.108.40.206) to eliminate dextran in sugar is an effective practice. In this study, a synthetic dextranase encoding gene of the filamentous fungus Talaromyces minioluteus, lacking its putative native signal peptide (1-20 amino acids) and the next 30 amino acids (r-TmDEX49A-ΔSP-ΔN30), was fused to the Saccharomyces cerevisiae prepro -factor (MF-2) signal sequence and expressed in Komagataella phaffii under the constitutive GAP promoter. K. phaffii DEX49A-ΔSP-ΔN30, constitutively producing and secreting the truncated dextranase was obtained. The specific activity of the truncated variant resulted nearly the same in relation to the full-length mature enzyme (900-1000 U.mg-1 of protein). At shaker scale (100 mL) in YPG medium, the enzymatic activity was 273 U.mL-1. The highest production level was achieved in a fed-batch culture (30 h) at 5 L fermenter scale using the FM21-PTM1 culture medium. The enzymatic activity in the culture supernatant reached 1614 U.mL-1 and the productivity was 53800 U.L-1.h-1 (53.8 mg.L-1.h-1), the highest reported so far for a DEX49A variant. Dextran decreased r-TmDEX49A-ΔSP-ΔN30 mobility in affinity gel electrophoresis, providing evidence of carbohydrate-protein interactions. K. phaffii DEX49A-ΔSP-ΔN30 shows great potential as a methanol-free, commercial dextranase production system.
ARTICLE | doi:10.20944/preprints202105.0571.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: Business intelligence; gender gap; information technology.
Online: 24 May 2021 (13:31:05 CEST)
In the early 1990s, cyberfeminism emerged as an area of knowledge to discuss the connection between gender and technology. According to UNESCO, women are underrepresented in the field of science, technology, engineering, and mathematics and less than a third of women worldwide work in scientific research and development. However, this number has grown and this reality is constantly changing. In this context, using business intelligence techniques, this study analyzes data from the computer and information and communication technology market to characterize the impact of the performance of women in these areas. It is expected to show that this performance in the highlighted fields is still a challenge in Brazil.
ARTICLE | doi:10.20944/preprints202011.0151.v1
Subject: Biology, Anatomy & Morphology Keywords: gap junctions; innexins; soma-germline interactions
Online: 3 November 2020 (14:01:49 CET)
In C. elegans, gap junctions couple cells of the somatic gonad with the germline to support germ cell proliferation and gametogenesis. We previously characterized a strong loss-of-function mutation (T239I) affecting the second extracellular loop (EL2) of the somatic INX-8 hemichannel subunit. These mutant hemichannels form non-functional gap junctions with germline-expressed innexins. Here we describe the characterization of mutations that restore germ cell proliferation in the T239I EL2 mutant background. We recovered seven intragenic mutations located in diverse domains of INX-8 but not the EL domains. These second-site mutations compensate for the original channel defect to varying degrees, from nearly complete wild-type rescue, to partial rescue of germline proliferation. One suppressor mutation (E350K) supports the innexin cryo-EM structural model that the channel pore opening is surrounded by a cytoplasmic dome. Two suppressor mutations (S9L and I36N) may form leaky hemichannels that support germline proliferation but cause the demise of somatic sheath cells. Phenotypic analyses of three other suppressors reveal an equivalency in the rescue of germline proliferation and comparable delays in gametogenesis but a graded rescue of fertility. These latter mutations may be useful to probe interactions with the biochemical pathways that produce the molecules transiting through soma-germline gap junctions.
ARTICLE | doi:10.20944/preprints202209.0382.v1
Subject: Materials Science, General Materials Science Keywords: ZnO; sol gel; temperature; band gap; simulation
Online: 26 September 2022 (07:42:25 CEST)
ZnO was synthesized by Sol gel method using zinc nitrate as precursor at different calcination temperatures. Nucleation of ZnO crystallites and their growth with rise in temperature was observed. Exciton bands and lattice imperfections affected the absorption spectra. The decrease in band gap with temperature was due to the formation of defect energy levels. Phonon assisted non-radiative transitions caused broadening of the peaks. The possibility of tuning the band gap of ZnO by changing the temperature was explored. Simulation studies showed transition to single phase with rise in temperature.
ARTICLE | doi:10.20944/preprints202012.0524.v3
Subject: Physical Sciences, Acoustics Keywords: Mass Gap Problem, Planck-Einstein relation, time, superfluid quantum space, bijectivity.
Online: 24 February 2021 (10:07:24 CET)
A given problem in physics can be solved if it is well formulated. Well formulated means that it has a bijective correspondence to physical reality. Mass Gap Problem has no bijective correspondence with the physical reality and is that’s why not solvable mathematically. It can be solved in the frame of quantum mechanics by the formulation of the photon’s mass accordingly to the Planck-Einstein relation.
ARTICLE | doi:10.20944/preprints201804.0174.v1
Subject: Chemistry, Electrochemistry Keywords: Perovskite materials; energy; band-gap; photo-efficiency.
Online: 13 April 2018 (06:41:48 CEST)
In a world where conventional sources of energy are fast depleting, the quest for alternative energy sources may hold the key for the survival of humanity. In the present work, emphasis has been given to the idea of producing energy from perovskite based solar cells. In order to bring this idea into fruition, a unique and novel nano structured perovskite material n-propyl ammonium lead chloride (C3H7NH3+PbCl3⁻) was prepared through a unique co-precipitation route using n-propyl amine (n-C3H7NH2) and hydrochloric acid as the starting precursors with aqueous solution of Pb(CH3COO)23H2O. Finally acetic acid was added to the solution and this solution was allowed to concentrate and then gradually cooled down to room temperature. After math, the synthesized material was spin-coated on TiO2 film to fabricate the solar cell. The device was then undergone systematic analysis using XRD, SEM, UV and Photo Conversion to get a transparent idea regarding its structural, electrical and optical properties. When experimentally applied, this perovskite-based solar cell has shown energy conversion efficiency (η) of around 6.01 % which is noticeably good. Thus it can be concluded that this material is promising for fabrication of vastly efficient solar cells. This technology can be tried in large scale as an alternative of conventional energy in the near future.
REVIEW | doi:10.20944/preprints202109.0041.v1
Subject: Life Sciences, Molecular Biology Keywords: connexin; gap junction; hemichannel; pannexin; peptide; cell signaling
Online: 2 September 2021 (13:38:54 CEST)
Gap junctions (GJ) and connexins play integral roles in cellular physiology and have been found to be involved in multiple pathophysiological states from cancer to cardiovascular disease. Studies over the last 60 years have demonstrated the utility of altering GJ signaling pathways in experimental models, which has led to them being attractive targets for therapeutic intervention. A number of different mechanisms have been proposed to regulate GJ signaling, including channel blocking, enhancing channel open state, and disrupting protein-protein interactions. The primary mechanism for this has been through the design of numerous peptides as therapeutics, that are either currently in early development or are in various stages of clinical trials. Despite over 25 years of research into connexin targeting peptides, the overall mechanisms of action are still poorly understood. In this overview, we discuss published connexin targeting peptides, their reported mechanisms of action and the potential for these molecules in the treatment of disease.
ARTICLE | doi:10.20944/preprints202007.0682.v1
Subject: Social Sciences, Economics Keywords: Business fluctuations; financial stability; output gap; weighted maturity
Online: 28 July 2020 (12:34:23 CEST)
Many countries have been facing the problem of bank insolvency across the globe. Asset deterioration is one of the main reasons for insolvency of banks. The objective of the paper is to ascertain the determinants of nonperforming loans (NPLs) in the banking sector of Pakistan for the period 2006-16. Other than the bank specific and macro variables proposed by the literature, the roles of weighted maturity and output gap are for the first time examined. We find significant impact of output gap on NPLs however weighted maturity has insignificant role in shaping the future NPLs. Bank specific drivers of NPLs include bank size and capital adequacy ratio.
ARTICLE | doi:10.20944/preprints201901.0306.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: Mental disorder, treatment gap, health system, Madhya Pradesh.
Online: 30 January 2019 (09:25:43 CET)
Background: India has one-fifth of the world's population and the number of people suffering from mental illness is assumed to be huge considering the contribution of mental disorders to the overall burden of the disease being 13.9 %. Objectives of Study: To estimate prevalence and patterns of mental illnesses to assess the current mental health services and systems in the Madhya Pradesh. Material and Methods: Multi-stage, stratified, random cluster sampling technique, with random selection based on probability proportionate to size at each stage. A total of 3240 individuals aged 18 years and above were interviewed. Both quantitative and qualitative methods were employed. A set of 10 instruments including Mini International Neuro-psychiatric Interview were utilized. Results: The overall weighted prevalence for any mental illness was 16.7% lifetime and 13.9% current. Treatment-gap for all mental health problems is as high as 91% in the state along with huge socioeconomic impact of mental illness. Conclusions: This huge burden of mental, behavioural and substance use disorders, in Madhya Pradesh, calls for immediate attention of political leaders, policy makers, health professionals, opinion-makers and society at large. It is hoped that the data from the study will inform mental health policy and legislation and help shape mental health care delivery systems in the country.
ARTICLE | doi:10.20944/preprints201901.0296.v1
Subject: Medicine & Pharmacology, Behavioral Neuroscience Keywords: episodic memory, apolipoprotein, dementia, biomarkers, anion gap, inflammation
Online: 29 January 2019 (16:52:14 CET)
Background: The Apolipoprotein E4 (ApoE4) genotype is strongly associated with Alzheimer’s disease (AD), although the presence of the ApoE4 allele alone is not sufficient to explain AD. The pathophysiology of amnestic mild cognitive impairment (aMCI) remains unclear. This study aims to examine associations between peripheral blood biomarkers coupled with ApoE4 and episodic and semantic memory. Methods: The CERAD battery was completed and various biomarkers were assayed in 60 subjects with aMCI, 60 with AD and 62 healthy controls. Results: Deficits in semantic and episodic memory were significantly predicted by anion gap and bicarbonate, albumin and glucose coupled with Apo E4. Furthermore, these peripheral biomarkers interacted with ApoE to predict greater memory impairments. Conclusions: Peripheral blood biomarkers may interact with pathways related to ApoE4 to predict greater semantic and episodic memory impairments, thus contributing to the pathophysiology of aMCI and AD. Our data suggest that the transition from aMCI to AD could at least in some cases be associated with significant interactions between ApoE4 and those peripheral blood biomarkers.
ARTICLE | doi:10.20944/preprints201807.0220.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: Synthesis, Crystal growth, Optical band gap, electrical susceptibility.
Online: 12 July 2018 (15:56:11 CEST)
A good optical quality crystal of 2-aminopyridine (2AP) metal complex crystals was grown by slow evaporation technique at room temperature. The transparent and defect less bulk size of 2-aminopyridine potassium dihydrogen orthophosphate metal complex crystals have been grown by solution growth method. The molecular structure and morphology of grown crystals was drawn and planes are indexed using WINXMORPH software. A optical absorption spectrum, the UV cut-off wavelength, Band gap (Eg), Reflectance (R), Refractive Index (n), Extinction coefficient (K) and Electrical susceptibility (χc) are calculated for 2AP metal complex crystals.
ARTICLE | doi:10.20944/preprints201612.0143.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Band-gap voltage reference; voltage reference; circuit design
Online: 29 December 2016 (15:47:33 CET)
By using 0.35-um CMOS process, this work achieves a design of analogous band-gap reference voltage circuit with low temperature coefficient. The proposed circuit operates at 3V and generates a reference current of 44 uA. The HSPICE simulation results show the temperature coefficient of this circuit is 23 ppm/℃ at range of -10 ℃ to 100 ℃, and the line regulation (the ratio of output current variation to supply voltage variation) is estimated as 1.95 uA/V from supply voltage variation of 3 V to 5 V. The experimental chip is fabricated and measured. The circuit provides adjustable capability for output voltage among temperature variation of -10 - 100 ℃. The chip area is 534 × 695 um^2. In this new design, the operational amplifier is not necessary. The chip design effort can be great reduced.
ARTICLE | doi:10.20944/preprints202107.0201.v1
Subject: Social Sciences, Accounting Keywords: Internet use; social capital; income gap between farmers; mechanism
Online: 8 July 2021 (13:26:17 CEST)
Based on 2010, 2013 and 2015 CGSS data, the impact of Internet use and social capital on the income gap among farmers in the past five years is assessed at three time points using the OLS method and a quantile regression method. The study finds that (1) the income gap among farmers increases continuously in the five-year period, while Internet use plays a positive impact on farmers’ income growth in all five quartiles; the coefficient differences are all significantly negative, indicating that Internet use plays a positive role in alleviating the income gap between high-income and low-income farmer subgroups, and (2) social capital plays a positive role in moderating the income gap among farmers and that Internet use by farmers expands the boundary of social capital, which in turn increases the income level of and alleviates the income gap among farmers.
Online: 22 October 2019 (15:40:00 CEST)
We use a random gap model to describe a metal-insulator transition in three-dimensional semiconductors due to doping and find a conventional phase transition, where the effective scattering rate is the order parameter. Spontaneous symmetry breaking results in metallic behavior, whereas the insulating regime is characterized by the absence of spontaneous symmetry breaking. The transition is continuous for the average conductivity with critical exponent equal to 1. Away from the critical point the exponent is roughly 0.6, which may explain experimental observations of a crossover of the exponent from 1 to 0.5 by going away from the critical point.
ARTICLE | doi:10.20944/preprints201909.0126.v1
Subject: Earth Sciences, Environmental Sciences Keywords: soil moisture; remote sensing; geostatistics; gap-filling; midwestern USA
Online: 12 September 2019 (03:32:21 CEST)
Soil moisture plays a key role in the Earth’s water and carbon cycles, but acquisition of continuous (i.e., gap-free) soil moisture measurements across large regions is a challenging task due to limitations of currently available point measurements. Satellites offer critical information for soil moisture over large areas on a regular basis (e.g., ESA CCI, NASA SMAP), however, there are regions where satellite-derived soil moisture cannot be estimated because of certain circumstances such as high canopy density, frozen soil, or extreme dry conditions. We compared and tested two approaches--Ordinary Kriging (OK) interpolation and General Linear Models (GLM)--to model soil moisture and fill spatial data gaps from the European Space Agency Climate Change Initiative (ESA CCI) version 3.2 (and compared them with version 4.4) from January 2000 to September 2012, over a region of 465,777 km2 across the Midwest of the USA. We tested our proposed methods to fill gaps in the original ESA CCI product, and two data subsets, removing 25% and 50% of the initially available valid pixels. We found a significant correlation coefficient (r = 0.523, RMSE = 0.092 m3m-3) between the original satellite-derived soil moisture product with ground-truth data from the North American Soil Moisture Database (NASMD). Predicted soil moisture using OK also had significant correlation coefficients with NASMD data, when using 100% (r = 0.522, RMSE = 0.092 m3m-3), 75% (r = 0.526, RMSE = 0.092 m3m-3) and 50% (r = 0.53, RMSE = 0.092 m3m-3) of available valid pixels for each month of the study period. GLM had lower but significant correlation coefficients with NASMD data (average r = 0.478, RMSE = 0.092 m3m-3) when using the same subsets of available data (i.e., 100%, 75%, 50%). Our results provide support for OK as a technique to gap-fill spatial missing values of satellite-derived soil moisture products across the Midwest of the USA.
ARTICLE | doi:10.20944/preprints201809.0334.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Adhesive, Dentin, Composite, Adaptation, Tooth, Optical coherence tomography, Gap
Online: 18 September 2018 (08:52:54 CEST)
Objectives: The current study aimed to compare the adaptation of the restored class-I cavities with two self-etch adhesives bonded to two resin composite using cross-polarization optical coherence tomography (CP-OCT). Materials and Methods: Cylindrical class-I cavities were prepared on twenty, extracted human premolars. Two self-etch adhesives; Clearfil SE bond 2 (SE; Kuraray Noritake Dental, Japan) and Bond Force (Palfique Bond) adhesive (PL; Tokuyama Dental, Japan) were used in this study that were bonded to either resin composites materials; Herculite XRV microhybrid dental composite (HRV; Kerr, Italy) or Estelite Alpha composite (ESA; Tokuyama Dental, Japan). The specimens were divided into four groups (n=5); SE-HRV, SE-ESA, PL-HRV and PL-ESA. All specimens were varnished and stored in distilled water for 24h. Then, they were submerged in a contrasting medium. After that, all groups were optically imaged under CP-OCT at every 250 µm interval distance. Later, image binarization and gap quantification were carried out using Image analysis software. Result: There was a significant difference between all the groups except between SE-ESA and PL-ESA (p = 0.51). The highest median gap % was seen in PL-HRV group followed by SE-ESA, PL-ESA and SE-HRV. Conclusion: Other than composite filler loading and adhesive formula, the interactions of the adhesive and composite copolymers have great influence on composite adaptation.
ARTICLE | doi:10.20944/preprints201805.0331.v1
Subject: Chemistry, Electrochemistry Keywords: conjugated polymer; selenophene; fluorine; carbazole band; gap; Suzuki coupling
Online: 24 May 2018 (05:32:43 CEST)
In this study, two donor-acceptor (D-A) type conjugated polymers namely PQSeCz and PQSeFl were designed and synthesized. Selenophene was incorporated as a π -bridge, quinoxaline as an acceptor unit while carbazole and fluorene were used as the donor units. Polymers were synthesized via palladium catalyzed Suzuki polymerization reaction. All molecules were characterized by 1H and 13C NMR Spectroscopy. The weight and number average molecular weights of the two polymers were determined by gel permeation chromatography (GPC). Electrochemical and spectroelectrochemical characterizations of the polymers were performed to investigate their optoelectronic properties. Oxidation potentials were 1.15 V/ 0.82 V and 1.11 V/ 0.82 V for PQSeCz and PQSeFl respectively, while reduction potentials were -1.26 V /-1.14 V and -1.48 V/ -1.23 V, respectively. In the visible region, maximum absorption wavelengths for the two polymers were 551 nm and 560 nm, respectively. Optical band gaps (Egop) were found from the lowest energy π – π∗ transition onsets as 1.71 eV and 1.58 eV, respectively. Both polymers showed good solubility in common solvents.
REVIEW | doi:10.20944/preprints201803.0168.v1
Subject: Life Sciences, Biochemistry Keywords: connexins; gap junctions; transcription; translation; post-translational modifications; trafficking
Online: 20 March 2018 (05:27:38 CET)
Connexins are tetraspan transmembrane proteins that form gap junctions and facilitate direct intercellular communication, a critical feature for the development, function and homeostasis of tissues and organs. In addition, a growing number of gap junction-independent functions are being ascribed to these proteins. The connexin gene family is under extensive regulation at the transcriptional and post-transcriptional level, and undergoes numerous modifications at the protein level, including phosphorylation, which ultimately affects their trafficking, stability and function. Here, we summarize these key regulatory events, with emphasis on how these affect their multi-functionality in health and disease.
ARTICLE | doi:10.20944/preprints201712.0180.v1
Subject: Social Sciences, Education Studies Keywords: computer science; tertiary education; course selection; performance; gender gap
Online: 26 December 2017 (02:30:21 CET)
The aim of the present study is to investigate both the performance and preferences of males and females Computer Science (CS) graduates. In order to attain the above goal, a quantitative case study was conducted regarding 89 degrees, acquired from 2006 to 2012, from the Department of Computer Science and Technology, University of Peloponnese, Greece. The analysis of the data revealed that in terms of performance, no significant differences between the mean grades of males and females exist, in almost most of the courses included in the curriculum of the aforementioned CS department. Any statistically significant differences in performances were present in almost equal number of courses in favor of males and females. It seems also, that females performed better in the courses they selected more than males. Regarding preferences, in CS courses, it seems that gender differences are existent. Males preferred more than females did core programming courses and advanced topics of Software Systems, computer networks, computer engineering, robotics and mathematics, whereas females preferred more the study of algorithms and security issues, computer fractals, data management, computer architecture, and mobile communication. In addition, females preferred courses in reference with humanities and social sciences, CS terminology, and career opportunities. Yet, females did not select any of programming lab-based courses, computer engineering, computer network issues and robotics.
ARTICLE | doi:10.20944/preprints202009.0304.v2
Subject: Earth Sciences, Atmospheric Science Keywords: COVID-19; waste generation; waste collection; gap assessment; emergency plans
Online: 23 June 2021 (11:39:27 CEST)
The nationwide lockdown imposed to control the spread of novel coronavirus induced dramatic alterations in different sectors of the Nepalese governance, including Solid Waste Management (SWM) practices. The study identifies SW collection gaps in seven major cities of Nepal and highlights the municipal and public households on SW management practices before and during the lockdown to emphasize the linkage between COVID-19 and SWM. It includes information on solid waste status, collection frequency and coverage, workers safety practices, types of vehicles operated for collection and alternative methods adopted by households to manage SW during the lockdown. For this, 1329 households survey and key informant interviews were conducted in seven cities of Nepal during the lockdown. It was found that although the coverage of the collection service was similar during the pandemic, there was a drastic decrease in the collection frequency leading to a collection gap of around 570 tons/day. More than 50% of the surveyed households adopted no proper alternative measures as they claimed that they stored solid waste with proper management so that municipal authorities can take it. The study reveals poor occupational health and safety practices among the solid waste workers due to the unavailability of safety gears and equipment despite being aware of the modes of transmission of the virus. The pandemic exacerbated the challenges of smooth SWM as it is an essential and needy service. This study highlights the need for a timely strategic management framework to be developed by the government to continue the smooth SWM practices during the lockdown.
ARTICLE | doi:10.20944/preprints202104.0626.v1
Subject: Social Sciences, Accounting Keywords: Sexism; social networks; adolescence; digital gender gap, emotional well-being
Online: 23 April 2021 (10:01:04 CEST)
Despite gender equality being present in the social and political sphere, we still encounter aspects that are characteristic of sexism. Such aspects impact upon gender inequality and different types of violence towards women. The present article aims to examine the behaviour of adolescents from Huelva with regards to ambivalent sexism towards women on social networks and their influence on health. Further, we seek to uncover adolescent’s perceptions with regards to gender differences in the use of social networks, the relationship between sexism and women's emotional well-being was observed. The study sample was formed by young people aged between 14 and 16 years who were residing in rural and urban zones in the south of Spain. A mixed methods approach was taken. At a quantitative level, a sample of 400 young people was recruited. These were administered a questionnaire about sexism which was composed of two scales and has been validated at a national and international level. At a qualitative level, the study counted on 33 young people who participated in in-depth discussions via interviews and discussion groups. The results showed that sexism emerges in adolescence in the analysed sample from the south of Spain. This favoured a digital gender gap and was reinforced through social networks such as Instagram and Snapchat. Rising awareness and a critical view of the aforementioned sexism was shown on the behalf of females, particularly those from urban backgrounds.
ARTICLE | doi:10.20944/preprints202010.0273.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: data-driven optimization; climate change; harvest planning; optimality gap; forest
Online: 13 October 2020 (10:46:56 CEST)
Forest planners have traditionally used expected growth and yield coefficients to predict future merchantable timber volumes. However, because climate change affects forest growth, the typical forest planning methods using expected value of forest growth can lead to sub-optimal harvest decisions. We proposed in this paper to formulate the harvest planning with growth uncertainty due to climate change problem as a multistage stochastic optimization problem and use sample average approximation (SAA) as a tool for finding the best set of forest units that should be harvested in the first period even though we have a limited knowledge of what future climate will be. The objective of the harvest planning model is to maximize the expected value of the net present value (NPV) considering the uncertainty in forest growth and thus in revenues from timber harvest. The proposed model was tested on a small forest with 89 stands and the numerical results showed that the approach allows to have superior solutions in terms of net present value and robustness in face of different climate scenarios compared to the approach using the expected growth and yield. The SAA methods requires to generate samples from the distribution of the random parameter. Our results suggested that a sampling scheme that focuses on generating high number of samples in distant future stages is favorable compared to having large sample sizes for the near future stages. Finally, we demonstrated that, depending on the level of forest growth change, ignoring this uncertainty can negatively affect forest resources sustainability.
REVIEW | doi:10.20944/preprints201912.0171.v1
Subject: Social Sciences, Law Keywords: animal welfare legislation; animal cruelty; law enforcement; Australia; enforcement gap
Online: 12 December 2019 (10:07:56 CET)
Enforcement of animal welfare statutes are the primary protection given for the maintenance of animal welfare and prevention of cruelty. It is speculated that animal law enforcement in Australia has a number of weakness in the enforcement model. These weaknesses create a gap between the goals of animal law enforcement and the reality of the animal law justice system. This gap is defined as the ‘enforcement gap’. This paper identifies and investigates the causes of this gap. The hypothesized causes discussed are (1) the impact the public can have on reporting animal cruelty, (2) the reliance on charitable organizations as enforcement bodies, (3) the inconsistencies in animal welfare legislation, and (4) the role of the sentencing courts. Thus, the causes of the enforcement gap are multifactorial; derived from all stages of the enforcement process. Further research is needed to investigate the concepts raised in this paper. However, it is likely that a combination of structural change to enforcement agencies, legislative reform and public education is required to reduce the enforcement gap.
ARTICLE | doi:10.20944/preprints201806.0327.v1
Subject: Earth Sciences, Atmospheric Science Keywords: Gap filling, M-SSA, Monte Carlo test, Time series, LST
Online: 20 June 2018 (16:25:07 CEST)
Land Surface Temperature (LST) is a basic parameter in energy exchange between the land and atmosphere and is frequently used in many sciences such as climatology, hydrology, agriculture, ecology, etc. LST time series data have usually deficient, missing and unacceptable data caused by the presence of clouds in images, presence of dust in atmosphere and sensor failure. In this study, Singular Spectrum Analysis (SSA) algorithm was used to resolve the problem of missing and outlier data caused by cloud cover. The region studied in the present research included an image frame of MODIS with horizontal number 22 and vertical number 05 (h22v05). This image involved a large part of Iran and Turkmenistan and Caspian Sea. In this study, MODIS LST sensor (MOD11A1) was used during 2015 with 1×1 Km spatial resolution and day/night LST data (daily temporal resolution). The results of the data quality showed that cloud cover caused 36.37% of missing data in the studied time series with 730 day/night LST images. Further, the results of SSA algorithm in reconstruction of LST images indicated the Root Mean Square Error (RMSE) of 2.95 K between the original and reconstructed data in LST time series in the study region. In general, the findings showed that SSA algorithm using spatio-temporal interpolation in LST time series can be effectively used to resolve the problem of missing data caused by cloud cover.
ARTICLE | doi:10.20944/preprints201910.0080.v1
Subject: Physical Sciences, Particle & Field Physics Keywords: neutrino; neutrino’s flavor; neutrino oscillation; many-body interactions; superconducting energy gap; a quantized space-time; zero-point energy; lepton; Fermi’s golden rule; mass gap
Online: 8 October 2019 (08:47:19 CEST)
We herein described an investigation of a theory, which describes the energies of neutrinos and the source of neutrino oscillations. A series of experiments were conducted to show evidences of the existence a neutrino mass. We also applied theories to explain the reason for the extremely small energy of a neutrino, mainly by employing a vacuum-derived superconducting energy gap from the Bardeen–Cooper–Schrieffer ground state. Moreover, we succeeded in obtaining the transition probabilities of neutrinos’ flavors (i.e., in terms of neutrino oscillation). We focused on the fact that up- and down-quantized space pairs combine by the Lorentz forces, undertake Bose-Einstein condensation, and then create a superconducting energy gap at the energy level of the vacuum with quantum mechanics fluctuation. Eventually, the superconducting energy gap vanishes to form a real body of the neutrino. Furthermore, assuming that the speed of the neutrino is near the speed of light and exhibits Planck’s blackbody emissions, we derived many-body interactions of neutrinos and applied them in Fermi’s golden rule. As a result, the neutrino energy we calculated agreed well within the realms of the experimental results. The calculated transition probabilities of neutrino’s flavor also explain the experiment results very well.
ARTICLE | doi:10.20944/preprints202205.0261.v1
Subject: Social Sciences, Organizational Economics & Management Keywords: environmental behavior; financial industry; employee survey; behavioral acceptance; intention-behavior-gap
Online: 19 May 2022 (11:39:40 CEST)
The financial sector, too, is developing innovative services and products that have the potential to make a more positive impact on global environmental goals. However, research sheds little light on environmental attitudes and behavioral patterns of employees in this sector. There are multiple factors promoting or inhibiting environmental behavior. Those factors may be rooted in individual or subjective norms, but also social influence and to some extent financial incentives and benefits. A survey concerning the intention to improve and actually show ‘green behavior’ was developed based on widely used acceptance models which differentiate between desirable behavior and the intention to show such behavior. Employees are predominately responsive towards environmental behavior: 20% are convinced of the need to act in a “green” and sustainable manner, only 5% are hard to win over or are not accessible at all. Financial loss or benefits combined with social motives contribute to sustainable living whereas financial benefits alone actually hinder such behavior. The study underlines the existence of a intention-behavior gap: The intention to behave sustainably is built somewhat separately from various influences. There are moderating factors like sex, age and family status that influence the decisions. This then leads to a gap between intention and actual behavior.
ARTICLE | doi:10.20944/preprints202110.0455.v1
Subject: Life Sciences, Biophysics Keywords: connexin hemichannel; gap junction; oxidative stress; Inflammatory receptors; Fasudil; Y-27632.
Online: 29 October 2021 (13:12:44 CEST)
Connexin 43 (Cx43) is expressed in kidneys and constitutes a feedforward mechanism leading to inflammation in other tissues where they form hemichannels and gap junction channels. However, the possible functional relationship between these membrane channels and their role in damaged renal cells remains unknown. Here, analyses of ethidium uptake and thiobarbituric acid reactive species revealed that TNF-α plus IL-1β increase Cx43 hemichannel activity and oxidative stress in MES-13 cells, a cell line derived from mesangial cells. The latter also was accompanied by a reduction in gap junctional communication, whereas western blotting analysis showed a progressive increase of phosphorylated MYPT (a substrate of RhoA/ROCK) and Cx43 upon TNF-α/IL-1β treatment. Additionally, inhibition of RhoA/ROCK strongly diminished the TNF-α/IL-1β-induced activation of Cx43 hemichannels and reduction in gap junctional coupling. We propose that activation of Cx43 hemichannels and inhibition of cell coupling during pro-inflammatory conditions could contribute to oxidative stress and damage of mesangial cells via the RhoA/ROCK pathway.
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: motion capture; neural networks; reconstruction; gap filling; FFNN; LSTM; BILSTM; GRU
Online: 3 August 2021 (11:52:46 CEST)
Optical motion capture is a mature contemporary technique for the acquisition of motion data, alas it is non-error-free. Due to technical limitations and occlusions of markers, gaps might occur in such recordings. The article reviews various neural network architectures applied for gap filling problem in motion capture sequences within FBM framework providing the representation for body kinematic structure. The results are compared with interpolation and matrix completion methods. We found out, that for longer sequences simple linear feedforward neural networks can outperform the other, sophisticated architectures. We were also able to identify, that acceleration and monotonicity of input sequence are the parameters that have a notable impact on the obtained results.
ARTICLE | doi:10.20944/preprints202102.0051.v1
Subject: Materials Science, Biomaterials Keywords: Metal-Organic Framework; Photocatalysis; Band-Gap modulation; Strain Engineering; Catalyst Selectivity.
Online: 1 February 2021 (15:00:06 CET)
In recent years, the class of metal-organic framework (MOF) materials emerged. These materials' unique properties can be assigned to their structure, containing inorganic nodes connected with organic linkers. Due to their porosity and flexibility, MOFs have become suitable for various energy-related applications, including gas storage, hydrogen production and heterogeneous catalysis, and photocatalysis. Using DFT+U calculations, we show that the substitution of metal centers in inorganic nodes and the strain engineering of UiO-66 alters the electronic and optical properties of this material. We show that applying mechanical strain on UiO-66 enables the control of absorption coefficient in the UV-Vis spectrum and the photocatalytic processes' selectivity when reactants for several photocatalytic processes are present. The presented findings could lead to general strategies for designing novel MOFs for sustainable energy conversion applications.
ARTICLE | doi:10.20944/preprints201912.0191.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: nickelate superconductors; infinite-layer superconductors; London penetration depth; superconducting gap symmetry
Online: 15 December 2019 (14:02:04 CET)
Recently Li et al (2019 Nature 572 624) discovered a new type of oxide superconductor Nd0.8Sr0.2NiO2 with Tc = 14 K. To classify superconductivity in this infinite-layer nickelate experimental upper critical field, Bc2(T), and the self-field critical current densities, Jc(sf,T), reported by Li et al (2019 Nature 572 624), are analysed in assumption of s-, d-, and p-wave pairing symmetries and single- and multiple-band superconductivity. Based on deduced the ground-state superconducting energy gap, Δ(0), the London penetration depth, λ(0), the relative jump in electronic specific heat at Tc, ΔC/C, and the ratio of 2Δ(0)/kBTc, we conclude that Nd0.8Sr0.2NiO2 is type-II high-κ weak-coupled single-band s-wave superconductor.
ARTICLE | doi:10.20944/preprints201701.0077.v1
Subject: Engineering, Other Keywords: leaf area index; smartphone camera sensor; conifer forest; canopy gap fraction
Online: 17 January 2017 (09:59:36 CET)
Plant leaf area index (LAI) is a key characteristic affecting field canopy microclimate. In addition to traditional professional measuring instruments, smartphone camera sensors have been used to measure plant LAI. However, when smartphone methods were used to measure conifer forest LAI, very different performances were obtained depending on whether the smartphone was held at the zenith angle or at a 57.5° angle. To validate further the potential of smartphone sensors for measuring conifer LAI and to find the limits of this method, this paper reports the results of a comparison of two smartphone methods with an LAI-2000 instrument. It is shown that both methods can be used to reveal the conifer leaf-growing trajectory. However, the method with the phone oriented vertically upwards always produced better consistency in magnitude with LAI-2000. The bias of the LAI between the smartphone method and the LAI-2000 instrument was explained with regard to four aspects that can affect LAI: gap fraction, leaf projection ratio, sensor field of view (FOV), and viewing zenith angle (VZA). It was concluded that large FOV and large VZA cause the 57.5° method to overestimate the gap fraction and hence underestimate conifer LAI, especially when tree height is greater than 2.0 m. For the vertically upward method, the bias caused by the overestimated gap fraction is compensated for by an underestimated leaf projection ratio.
ARTICLE | doi:10.20944/preprints202012.0792.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Boreal forest; Multi-temporal LiDAR remote sensing; Crown Closure Monitoring; Tree Density; Gap Fraction; Vertical canopy cover; Gap probability; Spatial Autocorrelation; Height threshold; Spatial grid resolution
Online: 31 December 2020 (11:55:01 CET)
Monitoring crown closure evolution using multi-temporal Light Detection and Ranging (LiDAR) surveys is a method that we expect to be increasingly adopted given the availability of LiDAR sensors and the accumulating survey archives. However, little attention was devoted to comparing crown closure estimates from independent surveys. Although survey parameters cannot be modified after the data collection, we speculate that the error associated to crown closure estimates comparison can be reduced by selecting optimal post-survey parameters. In this study, we compared crown closure estimates of three airborne LiDAR surveys from 2018 (40 pt/m²) used as a reference, and two lower-density surveys from 2016 (4.5 pt/m²) and 2018 (2 pt/m²). We studied the effect of the height threshold used to separate canopy points and the grid resolution, using skewness and variance of lagged difference of crown closure. Crown closure estimates using low height thresholds were more different across surveys, resulting in higher root mean squared error (RMSE), bias and more different variograms. Results show that optimal height threshold was 3 m and grid resolution was 25 m, although there was room for decision (RMSE of 7% and 5%, and bias of 4% and 0% for 2016 and 2018 low-density surveys).
ARTICLE | doi:10.20944/preprints202205.0150.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: Pechini method; TiO2; CuO; anatase; tenorite; band gap; absorbance; diffuse reflectance; XPS
Online: 11 May 2022 (08:54:56 CEST)
High purity TiO2 and CuO powders were synthesized by the Pechini method, an inexpensive and easy-to-implement procedure to synthetize metal oxides. The variables of synthesis were the ethylene glycol:citric acid molar ratio and the pH. High reproducibility of the anatase and tenorite phase was obtained for all synthesis routes. The degree of purity of the powders was confirmed by XRD, FTIR, UV-vis absorption and XPS spectra. SEM and TEM images revealed the powders are composed by micrometer grains that can have a spherical shape (only in the TiO2) or formed by a non-compacted nanocrystalline conglomerate. FTIR spectra only vibrational modes associated to the TiO2 or CuO with a nanoparticle behavior. UV-vis absorption spectra revealed the values of maximum absorbance percentage of both systems are reached in the ultraviolet region, with percentages above 83 % throughout the entire visible light spectrum for the CuO system, a relevant result for solar cell applications. Finally, XPS experiments allow the observation of the valence bands and the calculation of the energy bands of all oxides.
ARTICLE | doi:10.20944/preprints202011.0525.v1
Subject: Engineering, Automotive Engineering Keywords: flexible functional device; thin film coating; slot-die; surface tension; coating gap
Online: 20 November 2020 (07:08:12 CET)
Slot-die coatings are advantageous when used for coating large-area flexible devices; in particular, the coating width can be controlled, and simultaneous multi-layer coatings can be processed. Till date, the effects of ink widening and coating gap on the coating thickness have only been considered in a few studies. To this end, we developed two mathematical models to accurately estimate the coating width and thickness considering these two effects. We used root mean square deviation (RMSD) to experimentally verify the developed method. The coating width was seen to increase and the coating thickness was seen to decrease when the coating gap was increased. Experimental results showed that the estimation performances of the coating width and thickness models were as high as 98.46 % and 95.8 %, respectively. We believe that the developed models can be useful for determining the coating conditions according to the ink properties to coat a functional layer with user-defined widths and thicknesses in both lab- and industrial-scale roll-to-roll slot-die coating processes.
ARTICLE | doi:10.20944/preprints202008.0567.v1
Subject: Materials Science, General Materials Science Keywords: Wide band gap semiconductor; Elastic modulus; Optic-electronic properties; Ab–initio calculations
Online: 26 August 2020 (08:57:57 CEST)
The electronic structure and some of its derived properties of Li2CaGeO4 compound have been investigated. The calculations have been performed using the full-potential linearized augmented plane wave plus local orbitals method and ultra-soft pseudo-potentials . The optimized lattice parameters are found to be ingood accord with experiment. Features such as bulk modulus and its pressure derivative, electronic band structure and density of states are reported. The elastic anisotropy of the crystal is discussed and visualized. Moreover, the optical properties reveal that Li2CaGeO4 compound are suitable candidates for optoelectronic devices in the visible and ultraviolet (UV) regions.
Subject: Mathematics & Computer Science, Analysis Keywords: lacunary function; gap function; centered polygonal numbers; Natural boundary; singularities; broom topology
Online: 19 February 2020 (11:43:50 CET)
This work investigates centered polygonal lacunary functions restricted from the unit disk onto symmetry angle space which is defined by the symmetry angles of a given centered polygonal lacunary function. This restriction allows for one to consider only the p-sequences of the centered polygonal lacunary functions which are bounded, but not convergent, at the natural boundary. The periodicity of the $p$-sequences naturally gives rise to a convergent subsequence, which can be used as a grounds for decomposition of the restricted centered polygonal lacunary functions. A mapping of the unit disk to the sphere allows for the study of the line integrals of restricted centered polygonal that includes analytic progress towards closed form representations. Obvious closures of the domain obtained from the spherical map lead to four distinct topological spaces of the "broom topology'' type.
ARTICLE | doi:10.20944/preprints201903.0006.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Forest hydrology; Canopy filtering; trace metal; throughfall; gap edge canopy; closed canopy.
Online: 1 March 2019 (11:29:55 CET)
Trace metals can enter some natural regions with low human disturbance from atmospheric circulation, but little information is available regarding how the canopy can retained trace metals. Therefore, a representative sub-alpine spruce plantation was selected to investigate the net throughfall fluxes of eight trace metals (Fe, Mn, Cu, Zn, Al, Pb, Cd and Cr) of closed canopy and gap-edge canopy from August 2015 to July 2016. Over a one-year observational period, the annual fluxes of Al, Zn, Fe, Mn, Cu, Cd, Cr and Pb were 7.29 kg·ha-1, 2.30 kg·ha-1, 7.02 kg·ha-1, 0.16 kg·ha-1, 0.19 kg·ha-1, 0.06 kg·ha-1, 0.56 kg·ha-1 and 0.24 kg·ha-1, respectively, in the deposited precipitation. The annual net throughfall fluxes of these trace metals were 1.73 kg·ha-1, 0.9 kg·ha-1, 1.68kg·ha-1, -0.032 kg·ha-1, 0.04 kg·ha-1, 0.018 kg·ha-1, 0.093 kg·ha-1 and 0.087kg·ha-1, respectively, in the gap-edge canopy and -1.6 kg·ha-1, 1.13 kg·ha-1, 1.65 kg·ha-1, -0.10 kg·ha-1, 0.05 kg·ha-1, 0.03 kg·ha-1, 0.26 kg·ha-1 and 0.15 kg·ha-1, respectively, in the closed canopy. The closed canopy displayed a greater filter effect on the trace metals from precipitation than did the gap-edge canopy in the sub-alpine forest. In the rainy season, the net filtering ratio of trace metals ranged from -66%-89% in the closed canopy and from -52% to 25% in the gap-edge canopy. However, the net filtering ratio of all trace metals was greater than 50% in the closed canopy in the snowy season. Therefore, the results suggested that the most trace metals moving through the forest canopy are taken up rather than by rainfall leaching; moreover, the closed canopy can efficiently take up trace metals in the snowy season.
ARTICLE | doi:10.20944/preprints201710.0190.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: mast cells; angiogenesis; endothelial cells; tube formation assay; co-culture; gap junction
Online: 31 October 2017 (03:51:50 CET)
Angiogenesis is a complex process that involves interactions between endothelial cells and various other cell types as well as the tissue microenvironment. Several previous studies have demonstrated that mast cells accumulate at angiogenic sites. In spite of the evidence suggesting a relationship between mast cells and angiogenesis, the association of mast cells and endothelial cells remains poorly understood. The present study aims to investigate the relationship between mast cells and endothelial cells during in vitro angiogenesis. When endothelial cells were co-cultured with mast cells, angiogenesis was stimulated. Furthermore, there was direct intercellular communication via gap junctions between the two cell types. In addition, the presence of mast cells stimulated endothelial cells to release angiogenic factors. Moreover, conditioned medium from the co-cultures also stimulated in vitro angiogenesis. The results from this investigation demonstrate that mast cells have both direct and indirect proangiogenic effects and provide new insights into the role of mast cells in angiogenesis.
ARTICLE | doi:10.20944/preprints201710.0043.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: BaxSr1-xTiO3 films; boltzmann modelling; optical band gap; deposition rate; stoichiometric content
Online: 9 October 2017 (05:20:59 CEST)
Thin films (100-400 nm) of BaxSr1-xTiO3 (0≤x≤1) deposited in RF-magnetron co-sputtering equipment are presented in this research work. The change of deposition rate, gap energy, and resistivity as a function of temperature- applied power change in the growth parameters was studied through the ISO colour-code lines constructed with MATLAB: By analysing the trend information and take into account the influence of the calculated "x" parameter with the Boltzmann profile fitting is proposed a method to allow a controlled set up of the RF-magnetron co-sputtering system and predict the Eg and resistivity values in the BaxSr1-xTiO3 solid solution with 0≤x≤1 for amorphous and crystalline phases. Also, a versatile tool to optimise the deposition process and material properties.
REVIEW | doi:10.20944/preprints202106.0048.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: SSCM; Mathematical Model; Systematic Literature Review; SSCM Modules; Sustainable Development Goals; Gap analysis
Online: 2 June 2021 (07:19:32 CEST)
The main purpose of this paper is to present a comprehensive view of the application mathematical models in the designing and implementing SSCM beside to solving problems and making decision. The research questions are: what mathematical models are used for designing and implementing sustainable supply chain management, how to use them, which industries implemented in, what modules of SSCM depth in and finally finding the gaps of researches. The methodology of research is Systematic Literature review through peer review papers which are published in high ranking journals. In this paper, First, we search all papers through scientific data bases like Scopus, science direct, MDPI, Springer, Google Scholar, then, screening papers based on the criteria such as subject of paper, journals impact factor which is published in-should be peer review journal- and relative content of the papers. Finally, we selected 245 papers with three steps screening through 2806 papers that they have enough quality and relative to our research goals for context analysis. Through context analysis, first we categorized the information of the papers and drew the current situation of researches in the framework of our topic. Then, we evaluate and compare the goals of sustainability and current situation and found the gapes, then, offered new suggestions like implementing SSCMs models in pollutant industries like casting industry, Heavy industry, coal Industry and so on. On the other hand, there are gaps in researches in some modules of SSCM such as packaging, designing products, etc.
ARTICLE | doi:10.20944/preprints202103.0391.v2
Subject: Physical Sciences, Particle & Field Physics Keywords: Neutron black holes; dark matter black holes; black hole mass gap; universe evolution
Online: 18 March 2021 (10:52:30 CET)
The origins of the stellar mass neutron black holes and supermassive dark matter black holes without the singularities are reported based on the 4-D Euclidean space. The neutron black holes with the mass of mBH = 5 – 15 msun are made by the 6-quark merged states (N6q) of two neutrons with the mass (m(N6q) = 10 m(n)) of 9.4 GeV/c2 that gives the black hole mass gap of mBH = 3 – 5 msun. Also, the supermassive black holes with the mass of mSMBH = 106 – 1011 msun are made by the merged 3-D states (J(B1B2B3)3 particles) of the dark matters. The supermassive black hole at the center of the Milky way galaxy has the mass of mSMBH = 4.1 106 msun that is consistent with mSMBH = 2.08 - 6.23 106 msun calculated from the 3-D states (J(B1B2B3)3 particles) of the dark matters with the mass of m(J) = 1.95 1015 eV/c2. In other words, this supports the existence of the B1, B2 and B3 dark matters with the proposed masses. The first dark matter black hole (primary black hole) was created at the big bang. This first dark matter black hole decayed to the supermassive dark matter black holes through the secondary dark matter black holes that are explained by the merged states of the J(B1B2B3)3 particles. The universe evolution is closely connected to the decaying process of the dark matter black holes since the big bang. The dark matter cloud states are proposed at the intermediate mass black hole range of mIMBH = 102 – 105 msun. This can explain why the dark matter black holes are not observed at the intermediate mass black hole range of mIMBH = 102 – 105 msun.
ARTICLE | doi:10.20944/preprints202112.0376.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Large-Scale Image Classification; Printed Chinese Character Recognition; Data Synthesis; GoogLeNet-GAP; Transfer Learning
Online: 22 December 2021 (16:31:53 CET)
In the field of computer vision, large-scale image classification tasks are both important and highly challenging. With the ongoing advances in deep learning and optical character recognition (OCR) technologies, neural networks designed to perform large-scale classification play an essential role in facilitating OCR systems. In this study, we developed an automatic OCR system designed to identify up to 13,070 large-scale printed Chinese characters by using deep learning neural networks and fine-tuning techniques. The proposed framework comprises four components, including training dataset synthesis and background simulation, image preprocessing and data augmentation, the process of training the model, and transfer learning. The training data synthesis procedure is composed of a character font generation step and a background simulation process. Three background models are proposed to simulate the factors of the background noise and anti-counterfeiting patterns on ID cards. To expand the diversity of the synthesized training dataset, rotation and zooming data augmentation are applied. A massive dataset comprising more than 19.6 million images was thus created to accommodate the variations in the input images and improve the learning capacity of the CNN model. Subsequently, we modified the GoogLeNet neural architecture by replacing the FC layer with a global average pooling layer to avoid overfitting caused by a massive amount of training data. Consequently, the number of model parameters was reduced. Finally, we employed the transfer learning technique to further refine the CNN model using a small number of real data samples. Experimental results show that the overall recognition performance of the proposed approach is significantly better than that of prior methods and thus demonstrate the effectiveness of proposed framework, which exhibited a recognition accuracy as high as 99.39% on the constructed real ID card dataset.
ARTICLE | doi:10.20944/preprints202110.0449.v1
Subject: Physical Sciences, Applied Physics Keywords: bismuth manganite; ceramics; composite; lead titanate; optical energy gap; surface morphology; Vis-NIR reflectance
Online: 29 October 2021 (10:13:45 CEST)
This work shows a correlation between light reflectance, absorption, and morphologies of series of (1-x) BM–x PT, (x = 0.0, 0.02, 0.04, 0.08, 0.12, 0.16, 0.24) ceramics composite. The (1-x) BM–x PT showed features of a black mirror with a low optical energy gap. The measured Vis-NIR diffused reflectance enabled the calculation of the energy gap using the modified Kubelka-Munk function. The estimated energy gap was lower than 1.5 eV related to low reflectance in the Vis-NIR range. Moreover, obtained histograms of grains, using scanning electron microscope, enabled the correlation between grains size and amount of lead titanate. We deduced from the ceramics surface morphology that marked porosity also induced reflectivity of low magnitude. We correlated the magnitude of the energy gap with phases of the BM-PT composite and with the electrical conductivity activation energy reported in the literature. Our results findings opened prospect studied materials for optical applications.
ARTICLE | doi:10.20944/preprints202107.0537.v1
Subject: Engineering, Automotive Engineering Keywords: engineering education; Forth Industrial Revolution; 4IR; skills gap; future of work; e-learning; didactics
Online: 23 July 2021 (10:50:42 CEST)
We are calling for a paradigm shift in engineering education. In times of the Fourth Industrial Revolution (“4IR”), a myriad of potential changes is affecting all industrial sectors leading to increased ambiguity that makes it impossible to predict what lies ahead of us. Thus, incremental culture change in education is not an option any more. The vast majority of engineering education and training systems, having remained mostly static and underinvested in for decades, are largely inadequate for the new 4IR labor markets. Some positive developments in changing the direction of the engineering education sector can be observed. Novel approaches of engineering education already deliver distinctive, student centered curricular experiences within an integrated and unified educational approach. We must educate engineering students for a future whose main characteristics are volatility, uncertainty, complexity and ambiguity. Talent and skills gaps across all industries are poised to grow in the years to come. The authors promote an engineering curriculum that combine timeless didactic tradition, such as Socratic inquiry, project-based learning and first-principles thinking with novel elements (e.g. student centered active and e-learning by focusing on the case study and apprenticeship pedagogical methods) as well as a refocused engineering skillset and knowledge. These capabilities reinforce engineering students’ perceptions of the world and the subsequent decisions they make. This 4IR engineering curriculum will prepare engineering students to become curious engineers and excellent communicators better navigating increasingly complex multistakeholder ecosystems.
ARTICLE | doi:10.20944/preprints202010.0554.v1
Subject: Physical Sciences, Nuclear & High Energy Physics Keywords: hadrons; baryons; mesons; quarks; gluons; QCD; hadronization; quark-gluon plasma; Yang-Mills mass gap
Online: 27 October 2020 (12:28:24 CET)
The rank-3 antisymmetric tensors which are the magnetic monopoles of SU(N) Yang-Mills gauge theory dynamics, unlike their counterparts in Maxwell’s U(1) electrodynamics, are non-vanishing, and do permit a net flux of Yang-Mills analogs to the magnetic field through closed spatial surfaces. When electric source currents of the same Yang-Mills dynamics are inverted and their fermions inserted into these Yang-Mills monopoles to create a system, this system in its unperturbed state contains exactly 3 fermions due to the monopole rank-3 and its 3 additive field strength gradient terms in covariant form. So to ensure that every fermion in this system occupies an exclusive quantum state, the Exclusion Principle is used to place each of the 3 fermions into the fundamental representation of the simple gauge group with an SU(3) symmetry. After the symmetry of the monopole is broken to make this system indivisible, the gauge bosons inside the monopole become massless, the SU(3) color symmetry of the fermions becomes exact, and a propagator is established for each fermion. The monopoles then have the same antisymmetric color singlet wavefunction as a baryon, and the field quanta of the magnetic fields fluxing through the monopole surface have the same symmetric color singlet wavefunction as a meson. Consequently, we are able to identify these fermions with colored quarks, the gauge bosons with gluons, the magnetic monopoles with baryons, and the fluxing entities with mesons, while establishing that the quarks and gluons remain confined and identifying the symmetry breaking with hadronization. Analytic tools developed along the way are then used to fill the Yang-Mills mass gap.
ARTICLE | doi:10.20944/preprints202107.0143.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: finite element method; hybrid magnetic equivalent circuit; the air gap flux density distribution; rotor shape.
Online: 6 July 2021 (12:21:49 CEST)
Recently, the demand for electric vehicle is increasing worldwide due to eco-friendly policies and stricter emission regulations. As a traction motor for electric vehicle, interior permanent magnet synchronous motors are mainly used. For the design of the interior permanent magnet synchronous motor, the magnetic equivalent circuit method, which is a method of lumped constant circuit, and the finite element method, which is a method of distributed constant circuit, mainly are used. Magnetic equivalent circuit method is useful for simple design through fast and intuitive parameters, but it cannot derive the distribution of magnetic field. The finite element method can derive an accurate magnetic field distribution, but it takes a long time to analyze and it is difficult to analyze intuitive design parameters. In this paper, magnetic equivalent circuit method and Carter coefficient are mixed for rotor structure design. This design method will be called the hybrid magnetic equivalent circuit method. Intuitive design parameters are derived through this hybrid magnetic equivalent circuit method. We will derive the Air gap flux density distribution according to rotor shape, no-load induced voltage, and cogging torque, and compare and verify it with the finite element method.
ARTICLE | doi:10.20944/preprints202007.0023.v1
Subject: Social Sciences, Economics Keywords: coronavirus pandemic (2019+); cycle; Hodrick-Prescott filter; output gap; Polish economy; secular stagnation; sustainability; trend
Online: 3 July 2020 (08:46:44 CEST)
The research problem was formulated as a question: are demand-supply shocks affecting the opening up of a negative or positive output gap? The hypothesis was formulated: demand-supply shocks have a significant impact on the opening up and deepening of the negative output gap, thereby causing real GDP to shrink or potential GDP to grow. The spatial range applies to Poland and the time period - 2008:Q1-2019:Q4. The methodology consists of three stages: the first is the decomposition of the time series using the TRAMO/SEATS on the components: seasonality, trend-cycle, irregular; the second - the decomposition of the trend-cycle component using the Hodrick-Prescott filter into two separate components; the third is the calculation of the output gap; forecast with VECM and IRF approximation. The ouput gap is in the range of - 11% to +10%. After cleaning it, the shock elements are between -2.2% and 2%. Demand-supply shocks open up and widen the negative output gap. Based on forecasts, the output gap will be positive by the end of 2022, close to 0% (optimal scenario), rising to 5% (optimistic scenario) and negative, deepening to -4% (pessimistic scenario). Two of these scenarios point to a growing risk of secular stagnation.
ARTICLE | doi:10.20944/preprints201910.0090.v1
Subject: Biology, Ecology Keywords: alpine forest gap; freeze-thaw cycle; fungi to bacteria ratio; snow cover depth; total phenol
Online: 8 October 2019 (10:57:01 CEST)
Alpine forest gaps can distribute snowfall, solar radiation and rainfall, thus inducing a heterogeneous hydrothermal microenvironment between the inside and outside areas of forest gaps. Additionally, the characteristics of the heterogeneous microenvironment could vary greatly across the gap location properties during winter and the growing season. To determine the response of total phenol loss (TPL) from the litter to alpine forest gap disturbance during decomposition, we conducted a field litterbag experiment within a representative fir (Abies faxoniana Rehd.) forest based on the gap location properties. The TPL and abundances of fungi and bacteria from two typical shrub species (willow, Salix paraplesia Schneid., and bamboo, Fargesia nitida (Mitford) Keng f.) were measured during the following periods over two years: snow formation (SF), snow cover (SC) snow melting (ST), the early growing season (EG) and the later growing season (LG). At the end of the study, we found that the snow cover depth, frequencies of the freeze-thaw cycle and the fungal copy g-1 to bacterial copy g-1 ratio had significant effects on the litter TPL. The abundances of fungi and bacteria decreased from the gap center to the closed canopy during the two SF, SC, ST and LG periods and reversed during the two EG periods. The TPL closely followed the same trend as the microbial abundance during the first year of incubation. In addition, both species had larger TPLs in the gap center during the first winter, first year and entire two years. These findings suggest that alpine forest gap formation accelerates litter TPL and plays a dual role during specific critical periods by distributing abiotic and biotic factors directly and indirectly. In conclusion, reduced snow cover depth and duration during winter warming under current climate change scenarios or as gaps vanish may slow litter TPL in alpine biomes.
ARTICLE | doi:10.20944/preprints201906.0287.v1
Subject: Materials Science, General Materials Science Keywords: nanocomposite, metal-polymer-interface, multilayer, structure-function correlation, indirect band gap, GISAXS, GIWAXS, UV-Vis.
Online: 27 June 2019 (11:11:33 CEST)
A new strategy to nanoengineer gold/fluorocarbon multilayer (ML) nanostructures is reported. We have investigated the morphological changes occuring at the metal-polymer interface in multilayer structures with varying volume fraction of gold (Au) and the kinetic growth aspect of the microscale properties of nano-sized Au in plasma polymer fluorocarbon (PPFC). Investigations were carried out at various temperatures and annealing time by means of grazing incidence small-angle and wide-angle X-ray scattering (GISAXS and GIWAXS). We have fabricated a series of multilayers with variying volume fraction (0.12, 0.27, 0.38) of Au and bilayer periodicity in ML structure. They show an interesting granular structure consisting of nearly spherical shaped nanoparticles within the polymer layer. The nanoparticle (NP) morphology changes due to the collective effects of NPs diffusion within ensembles in the in-plane vicinity and inter-layer with increasing temperature. The in-plane NPs size distinctly increases (from 1.9 to 4 nm) with increasing temperature. The NPs become more spherical thus reducing the surface energy. Linear growth of NPs with temperature and time shows diffusion-controled growth of NPs in the ML structure. The structural stability of the multilayer is controlled by the volume ratio of the metal in polymer. At room temperature UV-Vis shows a blueshift of the plasmon peak from 560 nm in ML Au/PTFE_1 to 437 nm in Au/PTFE_3. We have identified the fabrication and post-deposition annealing conditions to limit the Local Surface Plasmon resonance (LSPR) shift (from 〖∆λ〗_LSPR=180 nm (Au/PTFE_1) to 〖∆λ〗_LSPR=67 nm (Au/PTFE_3 ML)) and their optical response over a wide visible wavelength range. A variation in the dielectric constant of the polymer in precence of varying Au inclusion is found to be the main factor affecting the LSPR frequency. Our finding may provide insights in Nano engineering ML structure can be useful to systematically control the growth of NPs in polymer matrix.
ARTICLE | doi:10.20944/preprints201902.0108.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: semiconductor thin films; CSS; ion-exchange; XRD; SEM; p-type carriers; band gap; solar cell
Online: 13 February 2019 (10:24:01 CET)
Stabilized un-doped Zinc Telluride (ZnTe) thin films were grown on glass substrates under vacuum using closed space sublimation (CSS) technique. A dilute copper nitrate solution (0.1/100 ml) was prepared for copper doping known as ion exchange process in the matrix of ZnTe thin film. The reproducible polycrystalline cubic structure of undoped and Cu doped ZnTe thin films with preferred orientation (111) was confirmed by X-rays diffraction (XRD) technique. Lattice parameter analyses verified the expansion of unit cell volume after incorporation of Cu species into ZnTe thin films samples. The micrographs of scanning electron microscopy (SEM) were used to measure the variation in crystal sizes of samples. The energy dispersive X-rays was used to validate the elemental composition of undoped and Cu-doped ZnTe thin films. The bandgap energy 2.24 eV of ZnTe thin film decreased after doping Cu to 2.20 eV may be due to the introduction of acceptors states near to valance band. Optical studies showed that refractive index was measured from 2.18 to 3.24 whereas thicknesses varied between 220 nm to 320 nm for un-doped and Cu doped ZnTe thin film respectively using Swanepoel model. The oxidation states of Zn+2, Te+2 and Cu+1 through high resolution X-ray photoelectron spectroscopy (XPS) analyses was observed. The resistivity of thin films changed from ~107 Ω-cm for undoped ZnTe to ~1 Ω-cm for Cu-doped ZnTe thin film, whereas p-type carrier concentration increased from to respectively. These results predicted that Cu-doped ZnTe thin film can be used as an ideal, efficient and stable intermediate layer between metallic and absorber back contact for the heterojunction thin film solar cell technology.
ARTICLE | doi:10.20944/preprints202106.0306.v1
Subject: Chemistry, Analytical Chemistry Keywords: eutectic mixtures; hydrogen bond acceptor; hydrogen bond donor; design of experiments; Tauc plot; band gap energy
Online: 11 June 2021 (08:52:30 CEST)
Three ternary mixtures composed by choline chloride (ChCl), ethylene glycol (EG) and a second hydrogen bond donor (HBD) as ethanol (A), 2-propanol (B), and glycerol (C) were studied in terms of composition related to the band gap energy (BGE). A Design of Experiments (DoE) approach, and in particular a Simple Lattice three-components design, was employed for determining the variation of the BGE upon the composition of each system. UV-VIS analysis and subsequent Tauc plot methodology provided the data requested from the DoE and multivariate statistical analysis revealed a drop of the BGE in correspondence to specific binary compositions for systems A and B. In particular, a BGE of 3.85 eV was registered for the mixtures ChCl/EtOH (1:1), and ChCl/2-propanol (1:1), which represents one of the lowest values ever observed for these systems.
Subject: Physical Sciences, Nuclear & High Energy Physics Keywords: Multi-gap Resistive Plate Chamber; Time of Flight; particle identification; Time resolution; high energy physics experiments
Online: 16 July 2020 (13:06:13 CEST)
Multi-gap Resistive Plate Chamber has been attracting increasing attention and has been studied in recent decades because of its good efficiency, high time resolution and relatively low cost. It has become a new standard technology for the Time of Flight system in particle and high energy physics experiments. In this paper, we introduce the operation principle and structure of the MRPC detector and review the applications on the Time of Flight system in several famous experiments, such as STAR, CBM and SoLID. The performances including time resolution and particle identification are discussed in detail. Some recent advances and perspectives with regard to the future development of the next generation MRPC are also outlined.
REVIEW | doi:10.20944/preprints202112.0384.v1
Subject: Biology, Physiology Keywords: Gap junctions; Connexins; Connexons; Electrical coupling; Cx36; Coincidence detection; HCN channels; Neuronal synchronization; Lateral Excitation; Oscillatory activity
Online: 23 December 2021 (11:42:39 CET)
Electrical transmission between neurons is largely mediated by gap junctions. These junctions allow the direct flow of electric current between neurons, and in mammals are mostly composed of the protein connexin (Cx)36. Circuits of electrically coupled neurons are widespread in these animals, plus, experimental and theoretical evidence supports the notion that, beyond synchronicity, these circuits are able to perform sophisticated operations like lateral excitation and inhibition, noise reduction, as well as the ability to selectively respond upon coincident excitatory inputs. Although once considered stereotyped and unmodifiable, we now know that electrical synapses are subject to modulation and, by reconfiguring neural circuits, these modulations can alter relevant operations. The strength of electrical synapses depends on gap junction conductance, as well as on its functional interaction with the electrophysiological properties of coupled neurons. In particular, voltage dependent channels of the non-synaptic membrane critically determine the efficacy of transmission at these contacts. Consistently, modulatory actions on these channels have been shown to represent relevant mechanisms of plasticity of electrical synaptic transmission. Here we review recent evidence on the regulation of electrical synapses of mammals, the underlying molecular mechanisms, and the possible ways in which they affect circuit function.
ARTICLE | doi:10.20944/preprints202102.0533.v1
Subject: Physical Sciences, Optics Keywords: laser beam welding; welding with gap; keyhole dynamics; pore formation; multiphysical simulation; CFD; process optimization; mesh refinement
Online: 23 February 2021 (19:06:04 CET)
Keyhole laser beam welding (LBW) of stainless steel sheets with a gap in between is numerically simulated with a three-dimensional, transient multi-physical model for laser material processing. At first, the model’s ability to reproduce experimental results on a relatively coarse computational mesh within reasonable computing time, so as to serve as process optimization tool, is presented. An example of process optimization, where a given set of weld seam quality criteria is fulfilled by iteratively optimizing a secondary laser beam, is shown. The relatively coarse mesh, in combination with a good model calibration to the experimental conditions, allows for sufficiently fast simulations to use this approach for optimization tasks. Finally, using a finer spatial and temporal discretization, the dynamic processes in the vicinity of the keyhole leading to the formation of pores are investigated. The physical phenomena predicted by the simulation are coherent with experimental observations found in literature.
REVIEW | doi:10.20944/preprints201906.0118.v1
Subject: Chemistry, General & Theoretical Chemistry Keywords: beef tallow biodiesel; fatty acid esters; atomic charge; molecular dipole moment; HOMO-LUMO energy gap; electrostatic potential
Online: 13 June 2019 (09:37:39 CEST)
This study deals with computational analysis of dominant fatty acid ethyl esters characterized from the biodiesel produced from waste beef tallow by means of KOH catalyzed ethanol based transesterification. Ethyl palmitate, Ethyl Oleate, Ethyl Stearate and Ethyl Myristate were identified as dominant fatty acid esters and were computed for molecular analysis in Gaussian 09 software using Density Functional Theory (B3LYP method) with 6-31G* as basis set. Geometric parameters were in accordance with existing experimental values and population analysis exhibited negative charge for oxygen atoms, both positive & negative charge for carbon atoms in all ester molecules. The molecular dipole moment was higher for unsaturated ester molecule and quadruple moment proposed electronic dislocation in X+Y direction. Also, energy gap decreased slightly with increasing carbon chain but reduced drastically with increase in unsaturation. Electrostatic potential mapping displayed negative electrostatic potential for oxygen atoms in ester linkage of all ester molecules.
ARTICLE | doi:10.20944/preprints201709.0141.v1
Subject: Chemistry, General & Theoretical Chemistry Keywords: purine and рyrimidine bases; donor/acceptor properties; quantum-chemical calculations; frontier levels; middle energy gap; parameter φ
Online: 28 September 2017 (03:13:48 CEST)
We have studied the relative positions of the frontier levels determine the main electronic properties and reaction ability, there is important necessity to compare the MO of the purine and рyrimidine bases: adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U). The donor and acceptor properties are the fundamental characteristic of the conjugated molecules and can be quantitatively estimated by relative positions of the frontier molecular orbitals. The MO’s energies can be estimated experimentally or quantum-chemically. Analysis of the relative position of the frontier levels (calibrated by the energy gap) enables the investigation of the donor/acceptor properties of the RNA/DNA bases more detailed. The index φ0 is proposed for the quantitative quantum-chemical estimation of the donor ability of the conjugated molecules: it points on the shifting of the energy gap relative to the reference electron balanced system. The RNA/DNA bases divided strictly by two groups: predominantly donors (φ0 > 0.5) and predominantly acceptors (φ0 > 0.5). Each representative base of the first group forms the stable base pair the representative base of the second group the difference of indices Δφ0 should be optimal to enables the DNA replication.
ARTICLE | doi:10.20944/preprints202009.0192.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: connexin 43; gap junctions; cancer; intercellular communication; breast cancer; cell signaling; tunneling nanotubes; cell–cell communication; tumor microtubes
Online: 9 September 2020 (03:09:50 CEST)
Connexin 43 (Cx43) forms gap junctions that mediate the direct intercellular diffusion of ions and small molecules between adjacent cells. Cx43 displays both pro- and anti-tumorigenic properties, but the mechanisms underlying these characteristics are not fully understood. Tunneling nanotubes (TNTs) are long and thin membrane projections that connect cells, facilitating the exchange of not only small molecules, but also larger proteins, organelles, bacteria, and viruses. Typically, TNTs exhibit increased formation under conditions of cellular stress and are more prominent in cancer cells, where they are generally thought to be pro-metastatic and to provide growth and survival advantages. Cx43 has been described in TNTs, where it is thought to regulate small molecule diffusion through gap junctions. Here, we developed a high-fidelity CRISPR/Cas9 system to knockout (KO) Cx43. We found that loss of Cx43 expression was associated with significantly reduced TNT length and number in breast cancer cell lines. Notably, secreted factors present in conditioned medium stimulated TNTs more potently when derived from Cx43-expressing cells than from KO cells. Moreover, TNT formation was significantly induced by inhibition of several key cancer signaling pathways that both regulate Cx43 and are regulated by Cx43, including RhoA kinase (ROCK), protein kinase A (PKA), focal adhesion kinase (FAK), and p38. Intriguingly, drug-induced stimulation of TNTs was more potent in Cx43 KO cells than in wild-type cells. In conclusion, this work describes a novel non-canonical role for Cx43 in regulating TNTs, identifies key cancer signaling pathways that regulate TNTs in this setting, and provides mechanistic insight into a pro-tumorigenic role of Cx43 in cancer.
ARTICLE | doi:10.20944/preprints201810.0184.v1
Subject: Social Sciences, Sociology Keywords: technology adoption; Lorenz curves; Gini coefficient; local-national gap; Georgia; NIMBY; solar energy; community development; soft cost reduction
Online: 9 October 2018 (10:23:08 CEST)
Despite a global push in the development and implementation of widespread alternative energy use, significant disparities exist across given nation-states. These disparities reflect both technical and economic factors, as well as the social, political, and ecological gaps between how communities see energy development and national/global policy goals. Known as the “local-national gap,” many nations struggle with fostering meaningful conversations about the role of alternative energy technologies within communities. Mitigation of this problem first requires understanding the distribution of existing alternative energy technologies at the local level of policymaking. Using the State of Georgia, U.S.A. as a case study, we present a model for analyzing how existing adoption trends enable/limit conversation at the scale of local governance (i.e., county governments). Leveraging existing work on the Gini Coefficient as a metric for measuring energy inequity, we argue these tools can be applied to analyze where gaps exist in ongoing solar adoption trends. As we demonstrate, communities that adopt solar tend to be concentrated in a few counties, indicating existing conversations are limited to a circumscribed set of social networks. This information and the model we demonstrate can enable focused qualitative analyses of existing solar trends, not only amongst high-adoption areas but within communities where little to no adoption has occurred.
ARTICLE | doi:10.20944/preprints202004.0053.v1
Subject: Life Sciences, Genetics Keywords: calcium signaling; chemokine signaling; gap junction; NOD-like receptor signaling; oli-neu cells; pannexin1; PI3K-Akt pathway; thyroid hormone pathway
Online: 6 April 2020 (12:36:20 CEST)
We profiled the transcriptomes of primary mouse cortical astrocytes cultured alone or co-cultured with immortalized precursor oligodendrocytes. The experimental set-up (insert systems) prevented formation of gap junction channels but allowed free exchange of the two culture media. The study complements our previously published reports that the genomic fabrics of major functional pathways in oligodendrocytes are substantially remodeled by the proximity of non-touching astrocytes. Here, we present new analysis indicating that the transcriptomic landscape of astrocytes likewise changes significantly in the proximity of non-touching oligodendrocytes. The research was stimulated by the reported transcriptomic similarity between the brains of Cx43KO and Cx32KO mice, both substantially different from that of the Cx36KO mice. Since the three connexins are expressed in different cell types (Cx43 in astrocytes, Cx32 in oligodendrocytes and Cx36 in neurons), altogether these findings support the idea of a “panglial transcriptomic syncytium” in the mouse brain. Going further, our results suggest that integration in a heterocellular tissue modulates not only the expression profile but also the expression control and networking of the genes in each cell phenotype.
ARTICLE | doi:10.20944/preprints201706.0113.v1
Subject: Engineering, Control & Systems Engineering Keywords: conceptual modeling; cyber-physical systems; cyber-physical gap; Object-Process Methodology; model-based systems engineering; Three Mile Island 2 Accident
Online: 26 June 2017 (04:59:29 CEST)
: The cyber-physical gap (CPG) is the difference between the 'real' state of the world and the way the system perceives it. This discrepancy often stems from the limitations of sensing and data collection technologies and capabilities, and is an inevitable issue in any cyber-physical system (CPS). Ignoring or misrepresenting such limitations during system modeling, specification, design, and analysis can potentially result in systemic misconceptions, disrupted functionality and performance, system failure, severe damage, and potential detrimental impacts on the system and its environment. We propose CPG-Aware Modeling & Engineering (CPGAME), a conceptual model-based approach for capturing, explaining, and mitigating the CPG, on top of and in sync with the conventional system model, and as an inherent systems engineering activity. This approach enhances the systems engineer’s ability to cope with CPGs, mitigate them by design, and prevent erroneous decisions, actions, and hazardous implications. CPGAME is a generic, conceptual approach, specified and demonstrated with Object Process Methodology (OPM). OPM is a holistic conceptual modeling paradigm for multidisciplinary, complex, dynamic systems, which is also ISO-19450. We analyze the 1979 Three Miles Island 2 nuclear accident as a prime example of the disastrous consequences of unmitigated CPGs in complex systems.
Subject: Physical Sciences, Condensed Matter Physics Keywords: high Tc cuprates; macroscopic Boson; many-body interactions; pseudo gap; critical temperature; anomaly metal phase; conservation of angular momentum; attractive force; Cooper pair
Online: 30 September 2021 (15:07:34 CEST)
This study describes all the properties of high Tc cuprates by introducing rotating holes that are created by angular momentum conservations on a 2D CuO2 surface, and which have a different mass from that of a normal hole because of the magnetic field energy induced by the rotation. This new particle called a macroscopic Boson describes the doping dependences of pseudo-gap temperature and the transition temperature at which an anomaly metal phase appears and describes the origin of the pseudo-gap. Furthermore, this study introduces a new model to handle many-body interactions, which results in a new statistic equation. This statistic equation describing many-body interactions accurately explains why high Tc cuprates have significantly high critical temperatures. Moreover a partition function of macroscopic Bosons describes all the properties of anomaly metal phase, which sufficiently agree with experiments, using the result from our previous study  that analytically describes the doping dependence of Tc. By introducing a macroscopic Boson and the new statistical model for many-body interactions, this study uncovered the mystery of high Tc cuprates, which have been a challenge for many researchers. An important point is that, in this study, pure analytical calculations are consistently conducted, which agree with experimental data well (i.e., they do not use numerical calculations or fitting methods but use many actual physical constants).
ARTICLE | doi:10.20944/preprints201911.0033.v2
Subject: Physical Sciences, Condensed Matter Physics Keywords: temperature-independent superconductivity; circuit-approached superconductivity; electron pair; Bose–Einstein condensation; large superconducting energy gap; London equation; Meissner effect; macroscopic wave function; critical current density; negative voltages
Online: 15 July 2020 (03:30:06 CEST)
This paper proposes a method to generate a new type of superconductivity that is temperature independent with a high critical current density. This study is significant because the method does not require refrigeration, specific setups, or specific substances. That is, the method for generating the superconductivity is very simple. Many conventional superconductor studies have not yet reached this point. Moreover, compared with our previously developed superconductivity (PNS) [1-3], the critical currents in this study are much larger, which is important for practical applications. In the theoretical approaches, even though the mechanism of pairing, and the Bose–Einstein condensation are the same in this study as in PNS, the present paper emphasizes the mechanism of the Meissner effect in addition to formulating the critical current density. Further, we establish a simulation method with an equivalent circuit that reveals the superconductivity properties in terms of the transport current and the electromagnetic characteristics.The principles of the presented system are as follows:First a voltage source, a current source and a load are connected in series.Then, the voltage of the voltage source is adjusted to balance the voltage of the load.Under this condition, the balance of the two voltages provides a zero voltage between the taps of the current source and the generated current from the voltage source becomes zero because of the internal infinite resistance of the current source.As a result, the electric power generated by the two sources is zero, and therefore, the load cannot generate Joule heating because of energy conservation.However, the current from the current source (not the voltage source) is not zero; therefore, we can predict that the resistance of the load must be zero.A summary of our theory and numerical calculations is as follows. First, the strong combination of a two-electron pair is demonstrated. Then, given that two electrons combine extremely strongly because of the spin magnetic attractive force, analytical calculations of the center-of-mass motion of the Hamiltonian of the pair eventually result in a macroscopic wave function. From this macroscopic wave function, we derive a London equation using the concept of an internal toroid. The key point is that, when a sample exhibits a Meissner effect, it should release the additional energy from the internal magnetic field as a discharge current, which involves a negative voltage. Based on the inductance of this toroid, an equivalent circuit is produced. Using this circuit, we simulate this phenomenon, which results in the generation of a negative voltage and evidence of the Meissner effect, in addition to zero voltages and non-zero currents for the sample.
ARTICLE | doi:10.20944/preprints201812.0194.v2
Subject: Physical Sciences, General & Theoretical Physics Keywords: Artificial magnetic monopole; new electromagnetic equations; superconducting loop; stationary wave; conservation of momentum; Lorentz conservation; magnetic potential; Dirac equation; energy gap in vacuum; pair of two Cooper pairs
Online: 6 September 2021 (14:21:23 CEST)
The purpose of this paper is to demonstrate the existence of an artificial magnetic monopole and to introduce new electromagnetic equations by altering an electric field and a magnetic field vectors.As a principle device, a cylindrical condenser is prepared, and a superconducting loop is inserted into it. By this conduction, radial electric fields take a role as the centripetal force and both counterclockwise and clockwise motions are induced. As a result, a stationery wave is formed in which the nodes take a part in creating a monopole as follows.First, employing the Lorentz conservations and because node of the stationary wave has no phases, the momentum k and the vector potential A vanish and instead a magnetic potential appears in order to maintain the Lorentz conservation. This magnetic potential has relationship with an electric potential, and thus consequently, a dependent relationship is obtained between an electric field and a magnetic field vectors. Using this conclusive dependent relationship, we can derive new Maxwell equation assembly which are created by altering the electric field and the magnetic field vectors. In this process, we derive a divergent equation of magnetic fields which is not zero, i.e., the existence of a magnetic monopole. Employing these newly derived Maxwell equation, an electromagnetic wave is derived whose speed is the same as one the existing Maxwell equations provide. As a monopole configuration, this paper discusses the energy gap of the vacuum, which is a result of the Dirac equation and describes a monopole as pairs between two Cooper pairs (i.e. four electrons) whose interaction is a photon. As mentioned, because the total momenta and phases are zero, this paper defines the wave function as the Dirac function and demonstrate the condensation, employing the Bloch’s theorem. Moreover, using the macroscopic basic equations, we retrace the creation of the divergent magnetic field in view of macroscopic phenomenon., which provides results in this paper.In Result section in this paper, we succeeded in demonstrating the distribution of the divergent magnetic field of monopole in terms of both microscopic and macroscopic scales. Furthermore, Discussion section describes properties a magnetic monopole should follow.