3,086 research outputs found
Enhanced Understanding of Infectious Diseases by Fusing Multiple Datasets: A Case Study on Malaria in the Western Brazilian Amazon Region
BACKGROUND: A common challenge to the study of several infectious diseases consists in combining limited cross-sectional survey data, collected with a more sensitive detection method, with a more extensive (but biased) syndromic sentinel surveillance data, collected with a less sensitive method. Our article describes a novel modeling framework that overcomes this challenge, resulting in enhanced understanding of malaria in the Western Brazilian Amazon. METHODOLOGY/PRINCIPAL FINDINGS: A cohort of 486 individuals was monitored using four cross-sectional surveys, where all participants were sampled regardless of symptoms (aggressive-active case detection), resulting in 1,383 microscopy and 1,400 polymerase chain reaction tests. Data on the same individuals were also obtained from the local surveillance facility (i.e., passive and active case detection), totaling 1,694 microscopy tests. Our model accommodates these multiple pathogen and case detection methods. This model is shown to outperform logistic regression in terms of interpretability of its parameters, ability to recover the true parameter values, and predictive performance. We reveal that the main infection determinant was the extent of forest, particularly during the rainy season and in close proximity to water bodies, and participation on forest activities. We find that time residing in Acrelandia (as a proxy for past malaria exposure) decreases infection risk but surprisingly increases the likelihood of reporting symptoms once infected, possibly because non-naïve settlers are only susceptible to more virulent Plasmodium strains. We suggest that the search for asymptomatic carriers should focus on those at greater risk of being infected but lower risk of reporting symptoms once infected. CONCLUSIONS/SIGNIFICANCE: The modeling framework presented here combines cross-sectional survey data and syndromic sentinel surveillance data to shed light on several aspects of malaria that are critical for public health policy. This framework can be adapted to enhance inference on infectious diseases whenever asymptomatic carriers are important and multiple datasets are available
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Geographical Distribution of Fungal Plant Pathogens in Dust Across the United States
As the world's population grows, global food production will need to increase. While food production efficiency has increased in recent decades through pathogen control, climate change poses new challenges in crop protection against pathogens. Understanding the natural geographical distribution and dispersal likelihood of fungal plant pathogens is essential for forecasting disease plant spread. Here we used cultivation-independent techniques to identify fungal plant pathogens in 1,289 near-surface dust samples collected across the United States. We found that overall fungal pathogen community composition is more related to environmental conditions (in particular soil pH, precipitation and frost) than to agricultural hosts and practices. We also delimited five susceptibility geographical areas in the United States where different sets of pathogens tend to occur.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Thermomechanical characterization of an amylose-free starch extracted from cassava (Manihot esculenta, Crantz)
The aim of this study was to determine and compare the melting (Tm), glass transition (Tg) and mechanical relaxation (Tα) temperatures of a new waxy cassava starch. Thermal transitions measurements were obtained by Differential Scanning Calorimetry (DSC) and Dynamical Mechanical Thermal Analysis (DMTA). The experimental data showed a high correlation between water volume fraction and melting temperature (Tm) indicating that the Flory-Huggins theory can be used to describe the thermal behavior of this starch. The Tm of waxy cassava starch-water mixes were lower than a waxy corn starch-water reference system, but differences were not statistically significant. The mechanical relaxation temperatures taken at tan δ peaks were found 29–38 °C larger than Tg. The Tα and Tg measured for waxy cassava starch exhibited similar properties to the ones of waxy corn starch, implying that waxy cassava starch can be used in food and materials industry
Presupuesto y Programación para la construcción del Auditorio del SILAIS- Managua, Ubicado detrás del Hospital Alemán Nicaragüense, en la ciudad de Managua
Presupuesta la construcción de la obra del auditorio del SILAIS-Mangua, ubicado detrás del Hospital Alemán Nicaragüense, departamento de Managua, calcula los volúmenes de obra del proyecto, determina los costos unitarios de cada una de las etapas y sub etapas del proyecto, identifica el costo base de la obra, elabora la programación dela obra según las etapas y sub etapa
Development of virtual environments using technological tools and resources to achieve meaningful Teaching-learning process for Foreign Languages
The effect of the unpredictable pandemic due COVID-19 caused that face-to-face classes stop in many academic institutions around the world, including El Salvador. As a result of that unexpected situation, the necessity of using technology when teaching appeared. But, how can virtual environments be prepared to teach? It is in that way that in this academic paper it is discussed the impact of the pandemic on the education, especially in El Salvador and how the University of El Salvador face it. In addition to that, as an answer to the need of changing to virtuality, it presents a compilation of theoretical model, such as Leflore’s theory presentations, to fundament virtual environments giving them the capacity to mediate the relationship between teachers, students and content achieving harmony in virtuality. Also, it describes educational applications and tools for the teaching of a foreign language, and design of didactic material in order to create the best conditions for teachers and students when using virtual spaces. The most important Learning Management Systems, virtual tools, and theories were analyzed and describe so the reader can find useful resources to achieve a meaningful teaching-learning process for foreign languages when using virtual environments
Matériaux à base de maïs : de la qualité finale à la sélection variétale via le procédé de mise en forme
Que les matériaux à base de maïs soient considérés comme des substituts des matériaux plastiques, ou qu'ils se présentent comme des produits alimentaires expansés (céréales petit-déjeuner, biscuits...), il est important de pouvoir évaluer leurs propriétés mécaniques, pour adapter les conditions de transformation, favoriser la sélection de la matière première et optimiser leur qualité. Par analogie avec le modèle des solides composites, l'analyse thermomécanique dynamique (DMA) montre que le comportement dépend fortement de l'adhésion entre amidon et particules protéiques. Les variations de viscosité élongationnelle avec la teneur en protéines et son lien avec le module élastique E', pour T>Tg+30°C, suggèrent que cette morphologie est fonction des mécanismes d'écoulement et d'expansion lors du procédé. En établissant les relations structure-procédé-propriétés, ces travaux ont favorisé la sélection variétale et la conception de produits céréaliers à la texture optimisée
Analysis of the Polarization of a Single-Mode VCSEL Subject to Parallel Optical Injection
International audienceWe investigate experimentally and theoretically the polarization switching found in single-transverse-mode vertical-cavity surface-emitting lasers (VCSELs) when subject to parallel optical injection. Our analysis focuses on a recently observed state in which injection locking of the parallel polarization and excitation of the free-running orthogonal polarization of the VCSEL are obtained. A simple nonlinear dependence between the power of both linear polarizations and the frequency detuning is found. Also, the total power emitted by the VCSEL is constant and independent of the injected optical power and the frequency detuning. We check these results experimentally for a variety of frequency detunings and bias currents applied to the device. We report experimental and theoretical stability maps in the injected power-frequency detuning plane for different bias currents, identifying the regions in which the state is observed. A simple analytical expression that describes the map boundary for large and negative frequency detunings is obtained. This provides a simple method to extract the linear dichroism of the device
Evaluación inicial de riesgos por puestos de trabajos de la empresa SOPROLIM, ubicada en la ciudad de Managua
En el presente trabajo se desarrollará un plan de acción en materia de Higiene y Seguridad Industrial para la prevención de los factores de riesgos que presenten en las diferentes áreas de estudios de la empresa SOPROLIM y a través de este plan tomar las correspondientes medidas preventivas y correctivas, dando cumplimiento a las disposiciones que especifica la ley general de higiene y seguridad del trabajo
The Cosmology Large Angular Scale Surveyor
The Cosmology Large Angular Scale Surveyor (CLASS) is a four telescope array
designed to characterize relic primordial gravitational waves from inflation
and the optical depth to reionization through a measurement of the polarized
cosmic microwave background (CMB) on the largest angular scales. The
frequencies of the four CLASS telescopes, one at 38 GHz, two at 93 GHz, and one
dichroic system at 145/217 GHz, are chosen to avoid spectral regions of high
atmospheric emission and span the minimum of the polarized Galactic
foregrounds: synchrotron emission at lower frequencies and dust emission at
higher frequencies. Low-noise transition edge sensor detectors and a rapid
front-end polarization modulator provide a unique combination of high
sensitivity, stability, and control of systematics. The CLASS site, at 5200 m
in the Chilean Atacama desert, allows for daily mapping of up to 70\% of the
sky and enables the characterization of CMB polarization at the largest angular
scales. Using this combination of a broad frequency range, large sky coverage,
control over systematics, and high sensitivity, CLASS will observe the
reionization and recombination peaks of the CMB E- and B-mode power spectra.
CLASS will make a cosmic variance limited measurement of the optical depth to
reionization and will measure or place upper limits on the tensor-to-scalar
ratio, , down to a level of 0.01 (95\% C.L.)
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