Institution
Universidad Centroccidental Lisandro Alvarado
Education•Barquisimeto, Venezuela•
About: Universidad Centroccidental Lisandro Alvarado is a education organization based out in Barquisimeto, Venezuela. It is known for research contribution in the topics: Population & Context (language use). The organization has 1553 authors who have published 1477 publications receiving 12706 citations. The organization is also known as: UCLA.
Topics: Population, Context (language use), Genotype, Convex function, Cancer
Papers published on a yearly basis
Papers
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TL;DR: Analyzing the motion of approximately 1500 pedestrian groups under natural condition shows that social interactions among group members generate typical group walking patterns that influence crowd dynamics, demonstrating that crowd dynamics is not only determined by physical constraints induced by other pedestrians and the environment, but also significantly by communicative, social interaction among individuals.
Abstract: Human crowd motion is mainly driven by self-organized processes based on local interactions among pedestrians. While most studies of crowd behaviour consider only interactions among isolated individuals, it turns out that up to 70% of people in a crowd are actually moving in groups, such as friends, couples, or families walking together. These groups constitute medium-scale aggregated structures and their impact on crowd dynamics is still largely unknown. In this work, we analyze the motion of approximately 1500 pedestrian groups under natural condition, and show that social interactions among group members generate typical group walking patterns that influence crowd dynamics. At low density, group members tend to walk side by side, forming a line perpendicular to the walking direction. As the density increases, however, the linear walking formation is bent forward, turning it into a V-like pattern. These spatial patterns can be well described by a model based on social communication between group members. We show that the V-like walking pattern facilitates social interactions within the group, but reduces the flow because of its "non-aerodynamic" shape. Therefore, when crowd density increases, the group organization results from a trade-off between walking faster and facilitating social exchange. These insights demonstrate that crowd dynamics is not only determined by physical constraints induced by other pedestrians and the environment, but also significantly by communicative, social interactions among individuals.
950 citations
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Pablo de Olavide University1, King Juan Carlos University2, Northern Arizona University3, Colorado State University4, University of Córdoba (Spain)5, Instituto Potosino de Investigación Científica y Tecnológica6, University of La Serena7, University of Jaén8, University of Sfax9, State University of Feira de Santana10, University of New South Wales11, Universidad Técnica Particular de Loja12, National University of San Juan13, University of the Bío Bío14, Central University of Venezuela15, National University of La Pampa16, Virginia Tech College of Natural Resources and Environment17, Northeast Normal University18, Ohio State University19, Université du Québec à Montréal20, International Potato Center21, University of New England (Australia)22, Universidad Centroccidental Lisandro Alvarado23, Agricultural Research Organization, Volcani Center24, Office of Environment and Heritage25
TL;DR: Any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P, suggesting the provision of key services provided by these ecosystems could be negatively affected.
Abstract: The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.
667 citations
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TL;DR: The well diffusion test is simple, easy to reproduce, inexpensive, easy both to read and interpret, and has a good correlation to the reference NCCLS microdilution test and may represent an alternative method for antifungal drug susceptibility testing of Candida spp.
501 citations
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TL;DR: The prevalence of hypertension mirrored the world average in 3 cities but was lower in the rest of the countries, and hypercholesterolemia was highly prevalent even in countries of different socioeconomic levels.
400 citations
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TL;DR: The recent development of a cell culture system for A. marginale provides a potential source of antigen for the development of improved killed and live vaccines, and the availability of cell culture-derived antigen would eliminate the use of cattle in vaccine production.
Abstract: Anaplasmosis, a tick-borne cattle disease caused by the rickettsia Anaplasma marginale, is endemic in tropical and subtropical areas of the world. The disease causes considerable economic loss to both the dairy and beef industries worldwide. Analyses of 16S rRNA, groESL, and surface proteins have resulted in the recent reclassification of the order Rickettsiales. The genus Anaplasma, of which A. marginale is the type species, now also includes A. bovis, A. platys, and A. phagocytophilum, which were previously known as Ehrlichia bovis, E. platys, and the E. phagocytophila group (which causes human granulocytic ehrlichiosis), respectively. Live and killed vaccines have been used for control of anaplasmosis, and both types of vaccines have advantages and disadvantages. These vaccines have been effective in preventing clinical anaplasmosis in cattle but have not blocked A. marginale infection. Thus, persistently infected cattle serve as a reservoir of infective blood for both mechanical transmission and infection of ticks. Advances in biochemical, immunologic, and molecular technologies during the last decade have been applied to research of A. marginale and related organisms. The recent development of a cell culture system for A. marginale provides a potential source of antigen for the development of improved killed and live vaccines, and the availability of cell culture-derived antigen would eliminate the use of cattle in vaccine production. Increased knowledge of A. marginale antigen repertoires and an improved understanding of bovine cellular and humoral immune responses to A. marginale, combined with the new technologies, should contribute to the development of more effective vaccines for control and prevention of anaplasmosis.
384 citations
Authors
Showing all 1581 results
Name | H-index | Papers | Citations |
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Gabriel Grimaldi | 36 | 93 | 5137 |
Hooman Momen | 34 | 91 | 3660 |
Alberto Paniz-Mondolfi | 29 | 131 | 5461 |
Manuel Velasco | 25 | 185 | 2121 |
Miguel Angel Chiurillo | 18 | 68 | 1071 |
Ramfis Nieto-Martínez | 18 | 39 | 11317 |
Rafael Hernández-Hernández | 17 | 50 | 1354 |
Juan C. Piña-Crespo | 15 | 33 | 1476 |
Rafael Hernández Hernández | 13 | 30 | 594 |
Carlos Vásquez | 13 | 69 | 675 |
Rafael Bonfante-Cabarcas | 13 | 41 | 933 |
Maria Eugenia Marante | 12 | 25 | 361 |
Eunice Ugel | 12 | 33 | 4512 |
Jesús F. Torres-Peraza | 12 | 13 | 832 |
Frank Mendoza | 11 | 20 | 403 |