2,658 research outputs found
TESTING FOR DIFFERENTIAL EFFECTS OF FOREST FIRES ON HIKING AND MOUNTAIN BIKING DEMAND AND BENEFITS
Surveys of visitors to National Forests in Colorado were conducted to determine whether different fire ages and presence of crown fires have different effects on hiking and mountain biking recreation visits and benefits. Actual and intended behavior data were combined using a count-data travel cost model. The intended behavior trip questions asked about changes in number of trips due to the presence of a high-intensity crown fire, prescribed fire, and a 20-year-old high-intensity fire at the area respondents were visiting. Using the estimated recreation demand function, years since a non-crown fire had statistically significant positive effect on the trip demand of hikers. In contrast, presence of crown fires had no statistically significant effect on the quantity of hiker trips, but had a significant and negative effect on mountain biking trips. Crown fires also had a large effect on the value per trip, with crown fires increasing the value per hiking trip but lowering the value per mountain biking trip.Resource /Energy Economics and Policy,
Mobile Personal Healthcare System for Non-Invasive, Pervasive and Continuous Blood Pressure Monitoring: A Feasibility Study
Background: Smartphone-based blood pressure (BP) monitor using photoplethysmogram (PPG) technology has emerged as a promising approach to empower users with self-monitoring for effective diagnosis and control ofhypertension (HT).
Objective: This study aimed to develop a mobile personal healthcare system for non-invasive, pervasive, and continuous estimation of BP level and variability to be user-friendly to elderly.
Methods: The proposed approach was integrated by a self-designed cuffless, calibration-free, wireless and wearable PPG-only sensor, and a native purposely-designed smartphone application using multilayer perceptron machine learning techniques from raw signals. We performed a pilot study with three elder adults (mean age 61.3 ± 1.5 years; 66% women) to test usability and accuracy of the smartphone-based BP monitor.
Results: The employed artificial neural network (ANN) model performed with high accuracy in terms of predicting the reference BP values of our validation sample (n=150). On average, our approach predicted BP measures with accuracy \u3e90% and correlations \u3e0.90 (P \u3c .0001). Bland-Altman plots showed that most of the errors for BP prediction were less than 10 mmHg.
Conclusions: With further development and validation, the proposed system could provide a cost-effective strategy to improve the quality and coverage of healthcare, particularly in rural zones, areas lacking physicians, and solitary elderly populations
Interfacial Self-Assembly to Spatially Organize Graphene Oxide Into Hierarchical and Bioactive Structures
Multicomponent self-assembly holds great promise for the generation of complex and functional biomaterials with hierarchical microstructure. Here, we describe the use of supramolecular co-assembly between an elastin-like recombinamer (ELR5) and a peptide amphiphile (PA) to organise graphene oxide (GO) flakes into bioactive structures across multiple scales. The process takes advantage of a reaction – diffusion mechanism to enable the incorporation and spatial organization of GO within multiple ELR5/PA layers. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ImageJ software were used to demonstrate the hierarchical organisation of GO flakes within the ELR5/PA layers and the distribution profiles of GO throughout the ELR5/PA membranes. Furthermore,atomic force microscopy (AFM) revealed improved Young’s moduli of the ELR5/PA/GOmembranes compared to the ELR5/PA membranes. Lastly, we investigated biocompatibility of the ELR5/PA/GO membrane via various cell culture methods
Spatial Transferability of an Agent‑Based Model to Simulate Taenia solium control interventions
Background
Models can be used to study and predict the impact of interventions aimed at controlling the spread of infectious agents, such as Taenia solium, a zoonotic parasite whose larval stage causes epilepsy and economic loss in many rural areas of the developing nations. To enhance the credibility of model estimates, calibration against observed data is necessary. However, this process may lead to a paradoxical dependence of model parameters on location-specific data, thus limiting the model’s geographic transferability. Methods
In this study, we adopted a non-local model calibration approach to assess whether it can improve the spatial transferability of CystiAgent, our agent-based model of local-scale T. solium transmission. The calibration dataset for CystiAgent consisted of cross-sectional data on human taeniasis, pig cysticercosis and pig serology collected in eight villages in Northwest Peru. After calibration, the model was transferred to a second group of 21 destination villages in the same area without recalibrating its parameters. Model outputs were compared to pig serology data collected over a period of 2 years in the destination villages during a trial of T. solium control interventions, based on mass and spatially targeted human and pig treatments. Results
Considering the uncertainties associated with empirical data, the model produced simulated pre-intervention pig seroprevalences that were successfully validated against data collected in 81% of destination villages. Furthermore, the model outputs were able to reproduce validated pig seroincidence values in 76% of destination villages when compared to the data obtained after the interventions. The results demonstrate that the CystiAgent model, when calibrated using a non-local approach, can be successfully transferred without requiring additional calibration. Conclusions
This feature allows the model to simulate both baseline pre-intervention transmission conditions and the outcomes of control interventions across villages that form geographically homogeneous regions, providing a basis for developing large-scale models representing T. solium transmission at a regional level
GPS Tracking of Free-Ranging Pigs to Evaluate Ring Strategies for the Control of Cysticercosis/Taeniasis in Peru
Background Taenia solium, a parasitic cestode that affects humans and pigs, is the leading cause of preventable epilepsy in the developing world. T. solium eggs are released into the environment through the stool of humans infected with an adult intestinal tapeworm (a condition called taeniasis), and cause cysticercosis when ingested by pigs or other humans. A control strategy to intervene within high-risk foci in endemic communities has been proposed as an alternative to mass antihelminthic treatment. In this ring strategy, antihelminthic treatment is targeted to humans and pigs residing within a 100 meter radius of a pig heavily-infected with cysticercosis. Our aim was to describe the roaming ranges of pigs in this region, and to evaluate whether the 100 meter radius rings encompass areas where risk factors for T. solium transmission, such as open human defecation and dense pig activity, are concentrated. Methodology/Principal Findings In this study, we used Global Positioning System (GPS) devices to track pig roaming ranges in two rural villages of northern Peru. We selected 41 pigs from two villages to participate in a 48-hour tracking period. Additionally, we surveyed all households to record the locations of open human defecation areas. We found that pigs spent a median of 82.8% (IQR: 73.5, 94.4) of their time roaming within 100 meters of their homes. The size of home ranges varied significantly by pig age, and 93% of the total time spent interacting with open human defecation areas occurred within 100 meters of pig residences. Conclusions/Significance These results indicate that 100 meter radius rings around heavily-infected pigs adequately capture the average pig’s roaming area (i.e., home range) and represent an area where the great majority of exposure to human feces occurs
Factores domiciliarios asociados con la presencia de hidatidosis humana en tres comunidades rurales de JunÃn, Perú
Introduction. Hydatid disease, a zoonosis caused by the larval stage of the parasite Echinococcus granulosus, is a public health problem at national level, especially in those regions dedicated to raising livestock. By now, there are many factors, at individual level, that have been associated to the infection by E. granulosus; nevertheless there is not any previous report that explore the association between household characteristics and the presence of the disease among household members. Objective. To explore the association between household characteristics and the presence of hydatid disease among household members. Material and methods. We performed a cross-sectional study in the households of 3 rural communities located in JunÃn, we evaluated the association between household characteristics and the presence of hydatid disease by multiple logistic regression (MLR). Results. from 417 evaluated households, 56 (13%) of them had at least one positive case among its members. Multivariate analysis showed that households with three or more members, located in the community with the lowest quintile of poverty, that reported raising livestock, and with evaluation coverage greater than 25% were more likely to have at least one positive case among its members. Conclusion. The observed characteristics be taken into account in the preliminary definition of high-risk subgroups, optimizing the use of resources and improving the effectiveness of screening programs. Introducción. La hidatidosis, zoonosis producida por el estadio larvario de la taenia Echinococcus granulosus, es un problema de salud pública a nivel nacional, en especial en aquellas regiones dedicadas a la crianza de ganado. A la fecha, se han descrito factores, a nivel individual, asociados con la infección por E. granulosus; sin embargo, no se encontró reporte previo que explore la asociación entre caracterÃsticas de la vivienda y la presencia de esta enfermedad en alguno de sus miembros. Objetivos. Explorar la asociación entre las caracterÃsticas de la vivienda y la presencia de hidatidosis entre las personas que la habitan. Materiales y métodos. Se realizó un estudio transversal en viviendas de tres comunidades rurales de JunÃn. Se evaluó el grado de asociación entre las caracterÃsticas de la vivienda y la presencia de hidatidosis en el hogar mediante un análisis de regresión logÃstica múltiple (RLM). Resultados. De un total de 417 viviendas evaluadas, 56 (13%) de ellas tenÃan al menos un caso positivo entre sus miembros; luego del análisis de RLM se observó que aquellas viviendas con más de tres miembros, localizadas en la comunidad con quintil de pobreza más bajo, que refirieron crianza de animales, y con una cobertura de evaluación mayor al 25% presentaron una mayor probabilidad de tener al menos un caso de positivo entre sus miembros. Conclusión. Las caracterÃsticas observadas deben ser tomadas en cuenta para la determinación preliminar de subgrupos de alto riesgo, optimizando asà el uso de los recursos y mejorando la eficacia de los programas de despistaje
Morphological and molecular evidence of Oslerus osleri (Nematoda: Filaroididae) in the Andean fox (Lycalopex culpaeus)
Oslerus osleri is a cosmopolitan filaroid nematode that parasitizes the respiratory system of domestic and wild canids. Natural infection by O. osleri is reported in the Andean fox (Lycalopex culpaeus) in this study. Nematodes, enclosed in small and compact fibrous nodules of 1 to 5 mm in diameter, were found on the surface of the trachea near the bronchial bifurcation on four Andean foxes during necropsy (one from Cuzco, Peru and three from Northwestern Patagonia in Argentina). The nematodes were identified as O. osleri by morphological and molecular methods. Ribosomal and mitochondrial DNA analyses were performed amplifying the second internal transcribed spacer region (ITS-2), the partial cytochrome c oxidase 1 (cox1), and the large subunit of nuclear ribosomal RNA (LSU rRNA) genes. Sequences of the ITS-2 and LSU rRNA had a genetic variation of 1.5% and 1.0%, respectively, with previous sequences of O. osleri registered in Genbank. This is the first amplification of the cox1 gene of O. osleri and demonstrated an identity of 92% to Perostrongylus falciformis (KY365437), and 90% to Angiostrongylus cantonensis (KY779735) and Angiostrongylus costaricensis (AP017675).Fil: Gomez Puerta, Luis A.. Universidad Nacional Mayor de San Marcos; PerúFil: Flores, Verónica Roxana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de ZoologÃa. Laboratorio de ParasitologÃa; ArgentinaFil: Vega, RocÃo Marisol. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de ZoologÃa. Laboratorio de ParasitologÃa; ArgentinaFil: Brugni, Norma Leonor. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de ZoologÃa. Laboratorio de ParasitologÃa; ArgentinaFil: Viozzi, Gustavo Pedro. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de ZoologÃa. Laboratorio de ParasitologÃa; ArgentinaFil: Lopez Urbina, Maria T.. Universidad Nacional Mayor de San Marcos; PerúFil: Gonzalez, Armando E.. Universidad Nacional Mayor de San Marcos; Per
Ocurrencia de cestodos anormales: hallazgo de Taenia multiceps trirradiado
Three atypical cestodes with abnormal morphology were found in a domestic dog. The cestodes had a scolex with six suction cups and a triradiate strobila. All parasites were gravid cestodes. In addition, the dog was infested with 324 normal cestodes. Both cestodes (normal and abnormal) were morphologically and molecularly identified as Taenia multiceps. The sequences of the cytochrome c oxidase subunit 1 gene of the triradiate cestode and normal cestodes were identical to each other and had more than 99% similarity with other published and recorded sequences for T. multiceps. These findings represent the first record of atypical cestodes and massive cestode infestation by T. multiceps in a dog from Peru.Tres cestodos atÃpicos con morfologÃa anormal fueron hallados en un perro doméstico. Los cestodos tenÃan un escólex con seis ventosas y un estróbilo trirradiado. Todos los parásitos fueron cestodos grávidos. Además, el perro estaba infestado con 324 cestodos normales. Ambos cestodos (normales y anormales) fueron morfológica y molecularmente identificados como Taenia multiceps. Las secuencias del gen citocromo c oxidasa subunidad 1 del cestodo trirradiado y de los cestodos normales eran idénticas entre sÃ, y tenÃan más de 99% de similitud con otras secuencias publicadas y registradas para T. multiceps. Estos hallazgos representan el primer registro de cestodos atÃpicos e infestación masiva de cestodos por T. multiceps en un perro de Perú
Diagnóstico morfológico y molecular de Cyclocoelum mutabile (Trematoda: Cyclocoelidae) en el Perú
Cyclocoelum mutabile, un digeneo de la familia Cyclocoelidae, fue hallado parasitando los sacos aéreos de una polla de agua común (Gallinula chloropus), proveniente de alrededores del Refugio de Vida Silvestre Pantanos de villa, localizada en el distrito de Chorrillos en Lima, Perú. Un total de 7 parásitos fueron colectados e identificados por métodos morfológicos como C. mutabile. El diagnóstico fue confirmado por análisis molecular, amplificando los genes mitocondriales citocromo c oxidasa subunidad 1 (cox1) y deshidrogenasa NADH subunidad 1 (nad1). Las secuencias de nucleótidos de los aislados se compararon con secuencias previas de GenBank, y mostraron una similitud entre ellas (> 96%). Este hallazgo constituye el primer registro de C. mutabile para el Perú. Además, el trabajo realiza una breve descripción del parásito, asà como la discusión de sus hospederos y distribución geográfica en Sudamérica
Pruebas de Software del Sitio www.olx.com.co
En el contenido de este documento del análisis del resultado de plan pruebas hace parte integral de la metodologÃa de pruebas, se encuentra fundamentado en estándares de calidad que no solo permiten el seguimiento y correcciones a tiempo del software, sino que además se encuentra definido por etapas, facilitando el seguimiento y control de los procesos del proyecto en desarrollo y proporcionando a garantizar la operatividad y funcionalidad del sistema.In the content of this document, the analysis of the test plan result is an integral part of the testing methodology, it is based on quality standards that not only allow the monitoring and timely corrections of the software, but it is also defined by stages. , facilitating the monitoring and control of the processes of the project under development and providing to guarantee the operability and functionality of the system
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