ARTICLE | doi:10.20944/preprints202205.0285.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: El Salvador; Cervical cancer; Human papilloma virus (HPV); screen-and-treat; cervical precancer; HPV vaccine
Online: 23 May 2022 (05:15:50 CEST)
Cervical cancer is preventable through vaccination, early detection, and treatment of precancerous lesions. However, global inequalities mean that the disease remains a leading cause of cancer death around the world, with over 80% of new cases and 90% of deaths occurring in low and middle-income countries (LMICs). In El Salvador, joint efforts between the Ministry of Health (MoH) and the non-profit organization Basic Health International (BHI) have been in place since 2008 with the goal of reducing the country’s disease burden. While the World Health Organization’s (WHO) call to action to eliminate cervical cancer provided worldwide momentum to implement new public health initiatives, the COVID-19 pandemic disrupted ongoing programs and jeopardized plans for the future. The purpose of this manuscript is to describe the progress that El Salvador has achieved in improving cervical cancer prevention, the impact of the pandemic on current strategies, and potential solutions that can help the country meet the WHO’s strategic targets by 2030 to accelerate the elimination of cervical cancer.
ARTICLE | doi:10.20944/preprints202301.0358.v1
Subject: Earth Sciences, Geology Keywords: Landslide susceptibility; Multivariate Adaptive Regression Splines (MARS); GIS; earthquake; earthquake-induced landslides; rainfall-induced landslides; El Salvador; Central America
Online: 19 January 2023 (11:54:14 CET)
In January and February 2001, El Salvador was hit by two strong earthquakes that triggered thousands of landslides, causing 1,259 fatalities and extensive damage. The analysis of aerial and SPOT-4 satellite images taken a few days after the events allowed us to map 6,491 coesismic landslides, which occurred in 14 study areas extending for about 400 km2. Four different Multivariate Adaptive Regression Splines (MARS) models were produced by using different covariate sets and landslide inventories, the latter containing the slope failures triggered by an extreme rainfall event of November 2009 and those induced by the earthquakes of 2001. Moreover, two validation scenarios were employed, including the 25% and 95% of the mapped landslides, respectively. The results of our experiment revealed that: (i) MARS algorithm provides reliable predictions of coesismic landslides; (ii) models calibrated with rainfall-induced landslides predict with acceptable accuracy landslides caused by deep earthquakes and distributed over vast areas; (iii) the best accuracy is achieved by models trained with both preparatory and trigger variables; (iv) a small portion of the landslides produced by an earthquake can be used to calibrate MARS predictive models that help to identify slopes where yet unreported landslides may have occurred.
ARTICLE | doi:10.20944/preprints201809.0239.v2
Subject: Earth Sciences, Environmental Sciences Keywords: El Nino Southern Oscillation; ENSO, El Nino extreme events;
Online: 7 November 2018 (16:30:41 CET)
Observed ENSO statistics exhibits a non-gaussian behavior, which is indicative of the presence of nonlinear processes. In this paper we use the Recharge Oscillator model (ROM), a largely used Low-Order Model (LOM) of ENSO, as well as methodologies borrowed from the field of statistical mechanics to identify which aspects of the system may give rise to nonlinearities that are consistent with the observed ENSO statistics. In particular, we are interested in understanding whether the nonlinearities reside in the system dynamics or in the fast atmospheric forcing. Our results indicate that one important dynamical nonlinearity often introduced in the ROM cannot justify a non-gaussian system behavior, while the nonlinearity in the atmospheric forcing can instead produce a statistics similar to the observed. The implications of the non-Gaussian character of ENSO statistics for the frequency of extreme El Nino events is then examined.
ARTICLE | doi:10.20944/preprints202001.0260.v1
Subject: Earth Sciences, Environmental Sciences Keywords: ENSO; El Nino; La Nina; Crop Yield; Climate change
Online: 22 January 2020 (09:44:40 CET)
This study was conducted to investigate the impact of El Niño Southern Oscillation on rainfall distribution and productivity of major Agricultural crops in the Kembta Tembaro Zone of Southern Ethiopia over the past 30 years. Precipitation and temperature data were obtained from the National Meteorology Agency, crop data from the Central Statistical Agency of Ethiopia, and the Sea Surface Temperature data from the NOAA website. The rainfall trend had shown decreasing trend with high variability at all the stations (p<0.05). Over the same period, El Niño and La Niña event were observed and highly affected rainfall distribution. It was found that Coefficient Variation was greater than 30%, which indicates the area was prone to drought episodes. The impacts of the ENSO events on the yield of Maize, Wheat, Barely, Sorghum and Enset were assessed. Wheat and Maize were highly affected by the ENSO events. Enset was found to be more resistant crop to the influence of ENSO. Barely and Sorghum were affected at varying magnitude. Among the five chosen crop for this investigation two of the crops were seriously affected during the two extremes, i.e. El Niño and La Niña. From this investigation it is conclude that the overall cereal crop productivity was decreased and precipitation variability was noticed. So, having the information about ENSO phase in advance can be used to forecast ENSO and select crop types and varieties to maximize agricultural rain fed cereal crop productivity while minimizing the crop risk associated with seasonal rainfall and ENSO phases.
Subject: Earth Sciences, Other Keywords: El Niño; La Niña; statistical indices; climate change adaptation; Ethiopia
Online: 3 September 2020 (15:33:05 CEST)
El Niño is warming of the sea surface temperature of the Pacific Ocean. Extreme flooding, drought, lack of potable water for livestock and domestic use, food insecurity and market imbalance are associated with El Niño and La Niña in Ethiopia. Drought following El Niño caused 50 to 90% crop failure, in the eastern parts of Ethiopia. El Niño episodes are detected using different statistical indices such as Oceanic Nino Index (ONI), Agricultural Stress Index System (ASIS) and the Southern Oscillation Index (SOI), with magnitude ranging from weak to strong. Identifying the El Niño and La Niña seasons it is very important to adopt suitable adaptation strategies, which can resolve and/or reduce the negative impacts. Early warning and immediate support to the impacted areas have been carried out to minimize risks from El Niño animal feed for livestock from other areas has been transported to the vulnerable areas. Planting early maturing and drought resistant crops, supplementary irrigation, early waning information on weather and climate have been exercised as climate change adaptation strategies, early warning mechanisms by the government of Ethiopia. El Niño and La Niña are natural phenomena; however, it is necessary to study the occurrence and distribution of El Niño and La Niña episodes to enable early warning and identify suitable adaptation strategies and policy implications in the country.
REVIEW | doi:10.20944/preprints201807.0015.v1
Subject: Earth Sciences, Atmospheric Science Keywords: El Niño Southern Oscillation, ENSO, health, climatic variability, climate-sensitive disease
Online: 2 July 2018 (16:13:56 CEST)
El Niño Southern Oscillation (ENSO) is an important of mode of climatic variability that through altering climate patterns exerts a discernible impact on ecosystems and society. For this reason, ENSO has attracted much interest in the climate and health science community with many analysts investigating ENSO health links through considering the degree of dependency of the incidence of a range of climate diseases on the occurrence of El Niño events. Because of the mounting interest in the relationship between ENSO as a major mode of climatic variability and health this paper presents an overview of the basic characteristics of the ENSO phenomenon and its climate impacts, discusses the use of ENSO indices in climate and health research and outlines the present understanding of ENSO health associations. Also touched upon are ENSO-based seasonal health forecasting and the possible impacts of climate change on ENSO and the implications this holds for future assessments of ENSO health associations. The review concludes that there is still some way to go before a thorough understanding of the association between ENSO and health is achieved with a need to move beyond analyses undertaken through a purely statistical lens with due acknowledgement that ENSO as a complex non-canonical phenomenon and that simple ENSO health associations should not be expected.
ARTICLE | doi:10.20944/preprints201806.0202.v1
Subject: Engineering, Construction Keywords: marble cutting waste; stabilized clay bricks; hydrated lime; Shaq El-Thoban
Online: 13 June 2018 (05:23:31 CEST)
This study evaluates the feasibility of stabilizing clay bricks with marble cutting waste (MCW). This waste currently discarded in huge quantities as a sludge resulted from sawing the marble blocks to slabs, grinding and polishing of marble processes to the landfills located around the marble processing factories located in the Shaq El-Thoban industrial zone, Cairo governorate, Egypt causing negative impacts on the environment, health and sustainable development. Experimental investigations were carried out to explore the effect of addition of the MCW in different clay-base mixes at different percentages up to 25% at the expense of the hydrated lime. Cement, hydrated lime and MCW are the three types of solidification agents used, clay and sand were also added in the formulations of the unfired clay brick specimens. Laboratory cylindrical stabilized and compressed specimens were made, and then they were cured in a humidity chamber for 2 and 4 weeks, then after were air dried, tested and evaluated according to the Egyptian code for the building by the stabilized and compressed earth soil (ECBS, 2016). To enhance the durability of the cured specimens, transparent silicon – based paint was used for this purpose. The laboratory results demonstrate high potential usage of MCW based additives up to 15% incorporating HL. In addition, the used paint could be an effective treatment way for the use of stabilized bricks in a wet environment. The use of eco-friendly building materials will be a great contribution for the environmental advantages and suggest a remarkable economical alternative to the fired building units.
ARTICLE | doi:10.20944/preprints201809.0534.v1
Subject: Social Sciences, Geography Keywords: syndemic; El Niño; infectious disease; diarrhea; malaria; respiratory; cholera; spatial cluster; GIS
Online: 27 September 2018 (06:04:08 CEST)
El Niño is a quasi-periodic pattern of climate variability and extremes often associated with hazards and disease. While El Niño links to individual diseases have been examined, less is known about the cluster of multi-disease risk referred to as an ecosyndemic, which emerges during extreme events. The objective of this study was to explore a mapping approach to represent the spatial distribution of ecosyndemics in Piura, Peru at the district-level during the first few months of 1998. Using geographic information systems and multivariate analysis, two methodologies were employed to map disease overlap of 7 climate-sensitive diseases and construct an ecosyndemic index, which was then mapped and applied to another El Niño period as proof of concept. The main findings showed that many districts across Piura faced multi-disease risk over several weeks in the austral summer of 1998. The distribution of ecosyndemics were spatially clustered in western Piura among 11 districts. Furthermore, the ecosydemic index in 1998 when compared to 1983 showed a strong positive correlation, demonstrating the utility of the index. The study supports PAHO efforts to develop multi-disease based and interprogrammatic approaches to control and prevention, particularly for climate and poverty-related infections in Latin America and the Caribbean.
ARTICLE | doi:10.20944/preprints202105.0325.v1
Subject: Engineering, Automotive Engineering Keywords: Stochastic modelling; Climate change; Streamflow; El Nino/Southern Oscillation (ENSO), Extreme events modelling
Online: 14 May 2021 (11:43:06 CEST)
Water is essential to all life-forms including various ecological, geological, hydrological, and climatic processes/activities. With changing climate, associated El Nino/Southern Oscillation (ENSO) events appear to stimulate highly uncertain patterns of precipitation (P) and evapotranspiration (EV) processes across the globe. Changes in P and EV patterns are highly sensitive to temperature variation and thus also affecting natural streamflow processes. This paper presents a novel suite of stochastic modelling approaches for associating streamflow sequences with climatic trends. The present work is built upon a stochastic modelling framework HMM_GP that integrates a Hidden Markov Model with a Generalised Pareto distribution for simulating synthetic flow sequences. The GP distribution within HMM_GP model is aimed to improve the model's efficiency in effectively simulating extreme events. This paper further investigated the potentials of Generalised Extreme Value Distribution (EVD) coupled with an HMM model within a regression-based scheme for associating impacts of precipitation and evapotranspiration processes on streamflow. The statistical characteristic of the pioneering modelling schematic has been thoroughly assessed for their suitability to generate/predict synthetic river flows sequences for a set of future climatic projections. The new modelling schematic can be adapted for a range of applications in the area of hydrology, agriculture and climate change.
ARTICLE | doi:10.20944/preprints202008.0362.v1
Subject: Biology, Ecology Keywords: Astyanax; Spelaeomysis; Troglomexicanus; Speocirolana; Toro cave; Sierra de El Abra; troglomorphy; troglobite; stygobite
Online: 17 August 2020 (10:28:27 CEST)
The Astyanax species complex has two morphs: a blind, depigmented morph which inhabits caves in México and an eyed, pigmented surface-dwelling morph. The eyed morph can also be found in caves, sometimes hybridizing with the cave morph. This species complex has arguably become the most prominent model system among cave organisms for the study of evolutionary development and genomics. Before this study, 32 caves were known to be inhabited by the cave morph, 30 of them within the El Abra region. The purpose of this study was to conduct new surveys of the area and to assess some unconfirmed reports of caves presumably inhabited by troglomorphic fish. We describe two new localities, Sótano del Toro #2 and Sótano de La Calera. These two caves make a single hydric system together with the previously described cave of Sótano del Toro. The system is inhabited by a mixed population of troglomorphic, epigeomorphic and presumably hybrid fish. Furthermore, Astyanax cavefish and the mysid shrimp Spelaeomysis quinterensis show a phylogeographic convergence that supports the notion that the central Sierra de El Abra is a biogeographical region that has influenced the evolutionary history of its aquatic community across species. The presumptive location of its boundaries, which may limit cave-to-cave or surface-to-cave gene flow, are identified.
ARTICLE | doi:10.20944/preprints201809.0598.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: irrigation scheduling; Solanum lycopersicum; El Niño; water stress; decision support system; climate variability
Online: 30 September 2018 (05:48:20 CEST)
Irrigation scheduling is used by growers to determine the right amount and timing of water application. In most parts of Mozambique, 90% of the total yearly precipitation occurs from November to March. The El Niño Southern Oscillation (ENSO) phenomenon influences the climate in Mozambique and affects the water demand for crop production. The objectives of this work were to quantify the effects of ENSO phenomenon on tomato crop water requirements, and to create the AgroClimate irrigation tool (http://mz.agroclimate.org/) to assist farmers in improving irrigation management. This study was based on daily grid-based climate information from 1983 to 2016 from the Climate Forecast System Reanalysis. Daily crop evapotranspiration was calculated by Hargreaves equation and crop coefficients. This tool is available online and considers different planting dates, ENSO phases, and crop growing season lengths. Irrigation needs varied from less than 250 mm per growing cycle during winter to 550 mm during spring. Both El Niño and La Niña influenced the irrigation scheduling, especially from November to March. El Niño periods were related with increased water demand due to drier and warmer conditions while the opposite was observed for La Niña. The ENSO information might be used to understand climate variability and improve tomato irrigation scheduling in Mozambique.
ARTICLE | doi:10.20944/preprints201807.0502.v1
Subject: Arts & Humanities, History Keywords: Ellacuría; liberation theology; El Salvador; Catholicism; central America; philosophy; martyrdom; catholic education; Jesuits; UCA
Online: 26 July 2018 (04:23:28 CEST)
The life and work of Ignacio Ellacuría, S.J. is of radical vision, and revolutionary change. His dynamic life and works accompanied El Salvador and the Universidad Centroamericana through perhaps the most tumultuous years of the country’s history, yet there has been limited work done to examine his contributions. This paper shows how Ellacuría viewed the role of a Christian intellectual, and a Christian university within his philosophical and theological framework. I argue that Ignacio Ellacuría held, similarly to his soteriological views, that the intellectual must also be willing to sacrifice all for the sake of his/her work in a pattern of discipleship/martyrdom prefigured by his exemplars Christ and Socrates. It was this dedication to praxis and theory that western theology and philosophy had respectfully lost since their foundations which he sought to restore to a central role. In conclusion, the Christian intellectual and institution, according to Ellacuría, must use its voice and life in service of the people even to the point of martyrdom; he would argue, the implicit reason for Christian martyrdom and the crucifixion of Christ himself.
ARTICLE | doi:10.20944/preprints201907.0327.v2
Subject: Earth Sciences, Geochemistry & Petrology Keywords: El Teniente Cu-Mo deposit; Andean magmatism; subduction erosion; mantle source region contamination; hafnium isotopes
Online: 8 September 2019 (17:22:48 CEST)
We have determined Hf isotopic compositions of 12 samples associated with the giant El Teniente Cu-Mo deposit, Chile. The samples range in age from ≥8.9 to 2.3 Ma and provide information about the temporal evolution of their magmatic sources from the Late Miocene to Pliocene. Together with previously published data, the new analysis indicate a temporal decrease of 10 εHf(t) units, from +11.6 down to +1.6, in the 12.7 m.y. from 15 to 2.3 Ma. These variations imply increasing incorporation of continental crust through time in the magmas that formed these rocks. The fact that the samples include mantle-derived olivine basalts and olivine lamprophyres suggests that these continental components were incorporated into their mantle source, and not by intra-crustal contamination (MASH). We attribute the increase, between the Middle Miocene and Pliocene, of crustal components in the subarc mantle source below El Teniente to be due to increased subduction erosion and transport of crust into the mantle. The deposit formed above a large, long-lived, vertically zoned magma chamber that developed due to compressive deformation and persisted between the period ~7 to 4.6 Ma. Progressively more hydrous mantle-derived mafic magmas feed this chamber from below, providing heat, H2O, S and metals, but no unique “fertile” Cu-rich magma was involved in the formation of the deposit. As the volume of these mantle-derived magmas decreased from the Late Miocene into the Pliocene, the chamber crystallized and solidified, producing felsic plutons and large metal-rich magmatic-hydrothermal breccias that emplaced Cu and S into the older (≥8.9 Ma) mafic host rocks of this megabreccia deposit.
ARTICLE | doi:10.20944/preprints202008.0511.v1
Subject: Earth Sciences, Atmospheric Science Keywords: secular changes; sunspot cycles; Indian summer monsoon rainfall; droughts in India; medieval solar maximum; Maunder minima; El Nino
Online: 24 August 2020 (08:04:03 CEST)
We have defined M cycles as modified form of Gleissberg cycles to study the quasi-periodic secular changes in sunspot activity. Using direct and proxy observations for more than 1200 years we have provided evidence for the influence of the above M cyles on the monsoon rainfall variability and occurrences of major droughts in India. The solar cycle averages of All Indian summer monsoon rainfall (AISMR) and probability of observation of below or above normal AISMR is found to show correlated variations with changes in amplitude of sunspot cycles during the years 1901-2018 AD. Major droughts in India show a preference to occur during minima and declining phases of the M cycles during the years 650-2018 AD . We could generally find low probability of occurrence of droughts in India during the medieval solar maximum epoch ( 1100-1250 AD) and during most of the prolonged sunspot minima periods including the Maunder minima. The evolution of mean Indian summer monsoon rainfall during 650-1900 AD is studied using proxy data from multiple sources with maxima during the 12th century and minima during 14th and 19th centuries. The association of Indian droughts with El-Nino and the possibilities of long term prediction of Indian summer monsoon rainfall variability will be also discussed
ARTICLE | doi:10.20944/preprints201704.0097.v1
Subject: Physical Sciences, Other Keywords: entropy; natural time; complexity measures; seismic electric signals; Olami–Feder–Christensen model; electrocardiograms; El Nino/La Nina Southern Oscillation
Online: 17 April 2017 (10:26:18 CEST)
Natural time is a new time domain introduced in 2001. The analysis of time series associated with a complex system in natural time may provide useful information and may reveal properties that are usually hidden when studying the system in conventional time. In this new time domain, an entropy has been defined and complexity measures based on this entropy as well as its value under time-reversal have been introduced and found applications in various complex systems. Here, we review these applications in the electric signals that precede rupture, e.g., earthquakes, in the analysis of electrocardiograms, as well as in global atmospheric phenomena like the El Nino/La Nina Southern Oscillation.
REVIEW | doi:10.20944/preprints202210.0441.v1
Subject: Earth Sciences, Geology Keywords: Desert landscape; Coastal plain; Paleoflood record; El Niño proxies; Debris flow; Slack-water deposit; Braided streams; Desert pavement; Regolith denudation
Online: 28 October 2022 (07:09:58 CEST)
The coastal Peru, one of the driest deserts in the world, has recently experienced dramatic landscape changes and asset destruction during precipitation events due to El Niño. Nevertheless, catastrophic explanations for landscape variations and human responses to the so-called "Super" or "Mega" El Niños are recurrent in pre-Hispanic time, even if alternative hypotheses were provided in literature. A deeper understanding of the geological and archaeological record can improve the knowledge on the relationship between such a coupled atmosphere-ocean phenomenon and landscape processes. The bibliographic sources required for this purpose are scattered throughout various disciplines ranging from physical to human sciences, thus comprehensive databases were used to identify and screen the relevant studies. The results provide knowledge synthesis in order to identify critical gaps and suggest specific research goals. Inferred episodes of landscape change due to severe precipitations in late pre-Hispanic time are discussed and consistencies and inconsistencies exposed. Examples of variation in landscape response due to extensive human intervention are reported.
TECHNICAL NOTE | doi:10.20944/preprints202206.0078.v1
Subject: Engineering, Other Keywords: Climate and Weather; Climate Model; Heat Transport; Radiation Balance; Atmospheric circulation; sea surface temperature; Planetary boundary layer; El Niño-Southern Oscillation (ENSO)
Online: 6 June 2022 (09:38:23 CEST)
The study of long-term average weather patterns is known as climatology. It is a distinct field of study from meteorology and can be broken down into several subdivision. In order to predict the future, the knowledge of climatology is essential. In other words, with the help of climatology, we can figure out how likely it is that snow and hail will fall to the ground, and how much solar thermal radiation can reach a certain location etc. Climatology often focuses on how the climate has changed over time and how it has affected people and events. Both meteorology and climatology fall under the general term "meteorology", in particular, they are subdivision of research in the same field. In case of predicting the weather, meteorologists use variables such as humidity, air pressure, and temperature. This article's primary objective is to familiarize engineers with the fundamentals of climate and its processes so that they can effectively apply this knowledge to comprehend the climatic impact on water resources systems.