520 research outputs found

    The impact of significant input of fine sediment on benthic fauna at tributary junctions: a case study of the Bermejo-Paraguay River confluence, Argentina

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    This study examines the morphological features, suspended sediment inputs and hydraulic conditions within a large river in association with ecological patterns before and after a tributary confluence. In order to examine these effects, the macroinvertebrate distributions from three reaches of the Paraguay and Bermejo Rivers (Paraguay-Argentina) are investigated. The Bermejo River is a tributary that supplies significant quantities of fine sediment to the Paraguay River, primarily in suspension. Two reaches were examined on the Paraguay River, upstream and downstream of the Bermejo River junction, with the third study reach located on the Bermejo River, upstream of the confluence with the Paraguay River. The results provide clear evidence that a significantly increased loading of fine sediment at a river confluence has effects on the distribution and potential movement of benthic invertebrates in the lotic environment by representing physical barriers at affected sites. These effects may be important at both local and regional scales, and such increases in suspended sediment (especially associated with anthropogenic change) may thus pose a major threat to ecosystem integrity that has been historically underestimated

    Reply to Cleveland et al.’s “Detecting (trans)gene flow to landraces in centers of crop origin: lessons from the case of maize in Mexico”

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    Cleveland et al. (2005, Environ. Biosafety Res. 4: 197–208) offer useful suggestions for monitoring transgenes in landraces of maize, but we disagree with their statement that the scientific conclusions of our paper (Ortiz-García et al., 2005, Proc. Natl. Acad. Sci. USA 102: 12338–12343) are not justified. First, contrary to their perception, our survey was not designed to evaluate transgenes in the whole State of Oaxaca, but rather to monitor a specific portion of the District of Ixtlán de Juárez where the presence of transgenes had been reported previously by Quist and Chapela (2001, Nature 414: 541–543). Second, our paper described two methods for estimating frequencies of undetected transgenic seeds, while Cleveland et al. recommend a third approach that explicitly estimates effective population size. They argue that the effective population size of our seed samples is smaller than we assumed, leading to false claims about our detection accuracy. However, we employed a robust statistical approach to compensate for possible bias by using numbers of maternal plants, in addition to numbers of seeds, to provide a conservative estimate of the minimum number of independent samples. When we re-analyzed our 2004 data using effective population sizes, our conclusion that transgenic seeds were “absent or extremely rare” did not change, nor did the general range of possible frequencies of undetected transgenic seeds. Unlike Cleveland et al., we advocate using combined probability tests to analyze data across localities. Third, our critics argue that we accepted the null hypothesis that transgenes were absent. Actually, we assumed that transgenes were present in local landraces, and we used parameter estimation methods to calculate the probability of failing to detect transgenic individuals at a range of frequencies. In agreement with Cleveland et al., we reiterate that there is a clear need for additional surveys with rigorous sampling methods to provide estimates of transgene frequencies over broad geographic areas in Mexico

    A GLOBAL ANALYSIS OF THE INFLUENCE OF GOVERNANCE ON IMPROVING TOURISM COMPETITIVENESS

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    Objective: The objective of the study was to identify the influence of governance on tourism competitiveness as measured by tourism GDP per capita, using structural equation modeling.Methodology: The study was descriptive correlational and applied quantitative documentary approach. Data from secondary sources from the World Bank and The World Travel & Tourism were used to obtain measures of governance and tourism GDP for 172 countries during the year 2021.Results: Governance was found to have a significant influence on tourism competitiveness, with government effectiveness, regulatory quality and rule of law emerging as the main predictors of governance. It was also found that most countries with high tourism performance have good governance, especially those countries that are small and specialized in tourism. Developed countries enjoy a high governance index, but do not lead the ranking in tourism GDP per capita.  Countries with low tourism performance have poor governance.Conclusions: Governance is a crucial factor in the success or failure of the tourism sector, and the positive and significant relationship between governance and tourism competitiveness has important implications for the formulation of policies and strategies to promote sustainable tourism development

    Job satisfaction of public workers in Northern Peru during the COVID-19 pandemic

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    Objective: The objective of the study was to determine the job satisfaction of public workers in the provincial municipalities of the Tumbes region (Peru).Method:The method used was a descriptive, non-experimental cross-sectional design. The sample consisted of 319 male and female workers from the 3 provincial municipalities. A sociodemographic questionnaire and the Job Satisfaction Questionnaire were used as data collection instruments. Results: The results showed that only 10% of the participants had high job satisfaction. Within the dimensions, the majority showed low satisfaction (67%) with the remuneration received. No significant differences were found between men and women with respect to job satisfaction, and those with permanent employment status had lower levels than those who work on a temporary basis. Conclusions: It is concluded that most of the personnel working in the provincial municipalities of the Tumbes region have low levels ofjob satisfaction, so it is important to develop programs aimed at strengthening the bond and favorable attitude of workers with the institution where they work

    The earliest bird-line archosaurs and the assembly of the dinosaur body plan

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    © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology

    The Late Triassic Ischigualasto Formation at Cerro Las Lajas (La Rioja, Argentina): fossil tetrapods, high-resolution chronostratigraphy, and faunal correlations

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    Present knowledge of Late Triassic tetrapod evolution, including the rise of dinosaurs, relies heavily on the fossil-rich continental deposits of South America, their precise depositional histories and correlations. We report on an extended succession of the Ischigualasto Formation exposed in the Hoyada del Cerro Las Lajas (La Rioja, Argentina), where more than 100 tetrapod fossils were newly collected, augmented by historical finds such as the ornithosuchid Venaticosuchus rusconii and the putative ornithischian Pisanosaurus mertii. Detailed lithostratigraphy combined with high-precision U–Pb geochronology from three intercalated tuffs are used to construct a robust Bayesian age model for the formation, constraining its deposition between 230.2 ± 1.9 Ma and 221.4 ± 1.2 Ma, and its fossil-bearing interval to 229.20 + 0.11/− 0.15–226.85 + 1.45/− 2.01 Ma. The latter is divided into a lower Hyperodapedon and an upper Teyumbaita biozones, based on the ranges of the eponymous rhynchosaurs, allowing biostratigraphic correlations to elsewhere in the Ischigualasto-Villa Unión Basin, as well as to the Paraná Basin in Brazil. The temporally calibrated Ischigualasto biostratigraphy suggests the persistence of rhynchosaur-dominated faunas into the earliest Norian. Our ca. 229 Ma age assignment to Pi. mertii partially fills the ghost lineage between younger ornithischian records and the oldest known saurischians at ca. 233 Ma.Fil: Desojo, Julia Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Fiorelli, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Ezcurra, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Ramezani, Jahandar. Massachusetts Institute of Technology; Estados UnidosFil: Da Rosa, Átila. A. S.. Universidade Federal de Santa Maria; BrasilFil: von Baczko, Maria Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Trotteyn, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Montefeltro, Felipe C.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Ezpeleta, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Langer, Max C.. Universidade de Sao Paulo; Brasi

    Attitudes towards research in medical residents of a public pediatric hospital

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    Introduction: Research is an intentional process of constructing new knowledge and ideas, promoting the transformation of society. Health professionals must develop positive attitudes towards research since this will improve their professional performance and therefore improve the quality of patient care. Objective: Identify the attitudes towards research in resident doctors of a public pediatric hospital. Methods: The study was descriptive cross-sectional; 200 resident doctors were included. The "Research Attitudes Scale (EACIN)" of 39 items was applied. The T-Student test for independent samples was used to determine the difference in the scores of research attitudes, and the variables sex, type of specialty and work experience, while the Mann Whitney U test was used for the weekly work hours variable. Results: 58.5 % were female, 25 % (48) showed a positive affective attitude, 98 % (196) a positive cognitive attitude, 94 % (188) a positive behavioral attitude. In general, 96 % (192) had a positive attitude and 4 % (8) had a neutral attitude. The score obtained by resident physicians who performed surgical specialties was higher than that of those who performed clinical specialties (115.69 ± 6.02 versus 113.29 ± 5.93; p= 0.012). Conclusions: Most resident doctors have positive attitudes towards research, which could be beneficial to implement training programs and/or activities related to research in the hospital
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