1,301 research outputs found

    Conjunctival tumors in children: histopathologic diagnosis in 165 cases

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    ABSTRACT Purpose: Conjunctival tissue tumors have a varied presentation, and few series studies on pediatric patients have been published. The objective of this paper is to report the histopathologic diagnoses (spanning over 1988-2013) of conjunctival tumors in children younger than 14 years. Methods: We conducted a retrospective, descriptive, and observational study by reviewing the database of all children in whom a conjunctival tumor was surgically removed at Hospital de Ojos y Oídos "Dr. Rodolfo Robles V.," Benemérito Comité Pro Ciegos y Sordos de Guatemala. The data pertaining to gender, age, and histopathologic diagnosis of all cases was collected. The same ocular pathologist made all diagnoses. Results: One hundred sixty-five cases were found, with a mean age of 7.88 years, being 91 (55.15%) male subjects. Melanocytic lesions were the most common tumors found (30.91% of cases), with only one case (0.60%) being malignant. Conclusions: Melanocytic lesions were the most common tumors found, and of all the cases, only one was malignant; this was in a patient with xeroderma pigmentosum. These findings are consistent with those reported in other studies regarding the frequencies of the histopathology of conjunctival tumors in the pediatric population

    Long-term Occupancy (1900–2015) of an Egyptian Vulture Nest

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    Exploring spatial–temporal dynamics of fire regime features in mainland Spain

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    This paper explores spatial–temporal dynamics in fire regime features, such as fire frequency, burnt area, large fires and natural- and human-caused fires, as an essential part of fire regime characterization. Changes in fire features are analysed at different spatial – regional and provincial/NUTS3 – levels, together with summer and winter temporal scales, using historical fire data from Spain for the period 1974–2013. Temporal shifts in fire features are investigated by means of change point detection procedures – Pettitt test, AMOC (at most one change), PELT (pruned exact linear time) and BinSeg (binary segmentation) – at a regional level to identify changes in the time series of the features. A trend analysis was conducted using the Mann–Kendall and Sen's slope tests at both the regional and NUTS3 level. Finally, we applied a principal component analysis (PCA) and varimax rotation to trend outputs – mainly Sen's slope values – to summarize overall temporal behaviour and to explore potential links in the evolution of fire features. Our results suggest that most fire features show remarkable shifts between the late 1980s and the first half of the 1990s. Mann–Kendall outputs revealed negative trends in the Mediterranean region. Results from Sen's slope suggest high spatial and intra-annual variability across the study area. Fire activity related to human sources seems to be experiencing an overall decrease in the northwestern provinces, particularly pronounced during summer. Similarly, the Hinterland and the Mediterranean coast are gradually becoming less fire affected. Finally, PCA enabled trends to be synthesized into four main components: winter fire frequency (PC1), summer burnt area (PC2), large fires (PC3) and natural fires (PC4)

    Understanding wildfires in mainland Spain. A comprehensive analysis of fire regime features in a climate-human context

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    Understanding fire regime is a crucial step towards better knowledge of the wildfire phenomenon. However, the concept itself, in spite of its widespread use, still lacks a clear, widely accepted definition and there is no general agreement on which features define it best. In this paper we provide an in-depth characterization and description of fire regimes in three regions – Northwest, Hinterland and Mediterranean – comprising the whole of mainland Spain, to identify their key features. Data on number of fires, burned area, fire season and cause are retrieved from historical fire records for the period 1974–2010. Specifically, fire frequency, burned area, number of natural/human-caused fires, burned area from natural/human-caused fires, number of large fires (=500 ha), and burned area from large fires were examined for each region and fire season. We used a multi-group Principal Components Analysis approach to determine the importance of each fire regime feature. Next, climate and socioeconomic variables were explored using Multidimensional Scatterplots and Generalized Additive Models to find the extent to which fire regimes are controlled by either environmental, human, or both factors. Results revealed differences among regions and seasons in terms of the characteristics of their respective fire regimes. However, several common features have been identified as key components of fire regimes, regardless of region or fire season: fire frequency, number of large fires, and burned area from natural fires. In addition, results confirm that fire regime in the Northwest area mainly depends on human activity, especially during winter, in contrast to the Mediterranean region

    Obesity and overweight among the poor and marginalized in rural Mexico: impact analysis of the effect of school breakfasts on children aged five to eleven

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    This article estimates the effect of the School Breakfast Program (SBP) on overweight and obese Mexican children aged five to eleven living in a poor and marginalized rural context during 2012-2019. Using data from the 2012, 2016, 2018, and 2019 National Health and Nutrition Surveys (ENSANUT), as well as propensity score matching techniques, this research compares the usual food intake of a group of children enrolled on the SBP with a control group that were not. The results indicate that SBP recipients include more overweight children, and that these consume unhealthy foods, including sugary drinks, snacks, sweets, and desserts, more frequently than those in the control group. There was no significant difference in the children’s obesity between the two groups. These findings highlight the need for a more comprehensive school breakfast program, that is connected to the food and nutritional security approach and is designed and implemented according to each Mexican region’s specific alimentary requirements and socioeconomic needs.En este artículo, se analiza el efecto del Programa Desayunos Escolares en niños mexicanos de cinco a once años con sobrepeso y obesidad que viven en un contexto rural pobre y marginado durante 2012 a 2019. Utilizando datos de la Encuesta Nacional de Salud y Nutrición (Ensanut) de 2012, 2016, 2018 y 2019, así como técnicas de emparejamiento por puntaje de propensión, en esta investigación, se compara la ingesta habitual de un grupo de niños inscritos en Programa Desayunos Escolares con otro de control que no lo era. Los resultados indican que, entre los receptores de los Desayunos, se incluyen a más niños con sobrepeso, y que estos consumen alimentos poco saludables, incluidas bebidas azucaradas, bocadillos, dulces y postres, con mayor frecuencia que los del grupo de control. No constó diferencia significativa, sin embargo, en la obesidad de los niños entre los dos grupos. Tales hallazgos resaltan la necesidad de un programa de desayuno escolar más integral, vinculado al enfoque de la seguridad alimentaria y nutricional, y a que se diseñe e implemente de acuerdo con los requerimientos alimentarios y socioeconómicos de cada región de México

    Genetic analysis of post‐epizootic amphibian chytrid strains in Bolivia: Adding a piece to the puzzle

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    The evolutionary history and dispersal pattern of Batrachochytrium dendrobatidis (Bd), an emergent fungal pathogen responsible for the decline and extinctions of many species of amphibians worldwide, is still not well understood. In South America, the tropical Andes are known as an important site for amphibian diversification, but also for being a place where hosts are at greater risk of chytridiomycosis. In an attempt to understand the history and the geographic pattern of Bd‐associated amphibian declines in Bolivia, we isolated Bd from hosts at two locations that differ in their chronology of Bd prevalence and host survival outcome, the cloud forests of the Amazonian slopes of the Andes and Lake Titicaca in the altiplano. We genotyped Bd from both locations and sequenced the genome from the cloud forest isolate and then compared them to reference sequences of other Bd strains across the world. We found that the Bolivian chytrid isolates were nearly genotypically identical and that they belong to the global panzootic lineage (Bd‐GPL). The Bolivian Bd strain grouped with other tropical New World strains but was closest to those from the Brazilian Atlantic Forest. Our results extend the presence of Bd‐GPL to the central Andes in South America and report this hypervirulent strain at Lago Titicaca, where Bd has been detected since 1863, without evidence of amphibian declines. These findings suggest a more complex evolutionary history for this pathogen in Bolivia and may point to the existence of an old lineage of Bd that has since been extirpated following the arrival of the panzootic Bd‐GPL or that the timing of Bd‐GPL emergence is earlier than generally acknowledged.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162756/2/tbed13568_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162756/1/tbed13568.pd

    Testing Data Transformations in MapReduce Programs

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    MapReduce is a parallel data processing paradigm oriented to process large volumes of information in data-intensive applications, such as Big Data environments. A characteristic of these applications is that they can have different data sources and data formats. For these reasons, the inputs could contain some poor quality data that could produce a failure if the program functionality does not handle properly the variety of input data. The output of these programs is obtained from a number of input transformations that represent the program logic. This paper proposes the testing technique called MRFlow that is based on data flow test criteria and oriented to transformations analysis between the input and the output in order to detect defects in MapReduce programs. MRFlow is applied over some MapReduce programs and detects several defect
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