13 research outputs found

    Improvements to the X-ray Spectrometer at the Aerosol Laboratory, Instituto de Física, UNAM

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    Due to the demands of better (accurate and precise) analytical results using X-ray Fluorescence (XRF) at the Aerosol Laboratory, Instituto de Física, UNAM, it was necessary to carry out improvements in instrumentation and analytical procedures in the x-ray spectrometer located in this facility. A new turbomolecular vacuum system was installed, which allows reaching the working pressure in a shorter time. Characteristic x-rays are registered with a Silicon Drift Detector, or SDD, (8 mm thick Be window, 140 eV at 5.9 keV resolution), working directly in a high-vacuum, permitting the detection of x-rays with energies as low as 1 keV (Na Ka) and higher counting rates than in the past. Due to the interference produced by the Rh L x-rays emitted by the tube normally used for atmospheric and food analysis with Cl K x-rays, another tube with a W anode was mounted in the spectrometer to avoid this interference, with the possibility to select operation with any of these tubes. Examples of applications in atmospheric aerosols and other samples are presented, to demonstrate the enhanced function of the spectrometer. Other future modifications are also explained

    Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.

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    BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    How does diet influence the reproductive seasonality of tropical freshwater fish?: A case study of a characin in a tropical mountain river

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    Seasonal breeding of tropical freshwater fish may be synchronized with periods of high food consumption. We explored this hypothesis by studying the relationship between diet and reproductive activity of Creagrutus guanes (Teleostei, Characidae). Our results showed that C. guanes had a generalist and omnivorous diet dominated by aquatic insects (mainly Diptera larvae) and seeds. Creagrutus guanes did not show intersexual or ontogenetic variation in diet. Peaks of feeding activity during rainy months were not synchronized with breeding in dry months. Our results do not support the hypothesis that the reproductive season has to be synchronized with high food consumption. We discussed the hypothesis fat reserves may be an important factor for the desynchronization of peaks of feeding and reproduction as explanation of seasonal breeding of this species

    Current threats faced by Neotropical parrot populations

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    Made available in DSpace on 2018-12-11T16:49:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-01Consejo Nacional de Investigaciones Científicas y TécnicasAgencia Nacional de Promoción Científica y TecnológicaPsittaciformes (parrots, cockatoos) are among the most endangered birds, with 31% of Neotropical species under threat. The drivers of this situation appear to be manifold and mainly of anthropogenic origin. However, this assessment is based on the last extensive consultation about the conservation situation of parrots carried out in the 1990s. Given the rapid development of anthropogenic threats, updated data are needed to strategize conservation actions. Using a population approach, we addressed this need through a wide-ranging consultation involving biologists, wildlife managers, government agencies and non-governmental conservation organizations. We gathered up-to-date information on threats affecting 192 populations of 96 Neotropical parrot species across 21 countries. Moreover, we investigated associations among current threats and population trends. Many populations were affected by multiple threats. Agriculture, Capture for the Pet Trade, Logging, each of them affected > 55% of the populations, suggesting a higher degree of risk than previously thought. In contrast to previous studies at the species level, our study showed that the threat most closely associated with decreasing population trends is now Capture for the local Pet Trade. Other threats associated with decreasing populations include Small-holder Farming, Rural Population Pressure, Nest Destruction by Poachers, Agro-industry Grazing, Small-holder Grazing, and Capture for the international Pet Trade. Conservation actions have been implemented on < 20% of populations. Our results highlight the importance of a population-level approach in revealing the extent of threats to wild populations. It is critical to increase the scope of conservation actions to reduce the capture of wild parrots for pets.Instituto Multidisciplinario sobre Ecosistemas y Desarrollo Sustentable CONICET—Universidad Nacional del Centro de la Provincia de Buenos AiresJustus-Liebig-Universität Giessen Department of Animal Ecology and SystematicsTexas A&M University Schubot Exotic Bird Health Center Department of Veterinary Pathobiology College of Veterinary MedicineSociedade de Pesquisa em Vida Selvagem e Educação AmbientalUniversidade Federal de SergipePrograma Lapa Verde Centro Científico TropicalFacultad de Ciencias Naturales y Museo Universidad Nacional de La PlataArea de Conservación Pacífico Central ACOPAC Programa de Vida SilvestreWildlife Conservation SocietyAarhus UniversityGrupo de Ecología Conservación de Islas A.C. (GECI)University of California Department of Environment Science Policy & ManagementUniversidad Nacional Federico VillarrealUniversidade Federal de GoiásInstituto Venezolano de Investigaciones CientíficasProyecto Selva de Pino ParanáUnidos por las Guacamayas A. C.SELVA: Investigación para la conservación en el NeotrópicoInstituto Nacional de Tecnología AgropecuariaUniversity of BrasíliaUniversidade Federal da Paraíba Centro de Ciências Exatas e da NaturezaCentro Nacional de Pesquisa e Conservação de Aves Silvestres/ICMBioUniversidade Federal do Pará Instituto de Ciências BiológicasGuyra ParaguayUniversity of Colorado Department of Integrative BiologyThe World Parrot TrustBirdsCaribbeanFundacion del RioUniversitat de BarcelonaSociedad Conservacionista Audubon de VenezuelaUniversidad de Sancti Spíritus ¨José Martí Pérez¨Estación Biológica de Doñana CSICFundación Pro-BosqueCompañeros en Vuelo PIF-SVInstituto de Investigaciones Marinas y Costeras CONICET—Universidad Nacional de Mar del PlataUniversity of North Texas Biological SciencesOne Earth ConservationInstituto Espaço SilvestreUniversidade do Estado do AmazonasNational Aviary Conservation and Field ResearchUniversity of Cape TownBirdlife InternationalPaso PacíficoUniversidade de Passo FundoBiola UniversityMinisterio del Ambiente y los Recursos Naturales (MARENA)Universidad Michoacana de San Nicolas de HidalgoFundação Universidade Federal de Mato Grosso do SulAQUASISFundación Botánica y Zoológica de BarranquillaProvitaCIT Jujuy CONICET—UNJuFundación de Ciencias para el Estudio y la Conservación de la Biodiversidad (INCEBIO)UNESP Instituto de Biociências de BotucatuUniversidad Nacional Autónoma de México Estación Biología Chamela Instituto de BiologíaVinculación Interdisciplinaria para el Desarrollo Ambiental y lo SocialMesserli Research Institute University of Veterinary MedicineMuseo Noel Kempff MercadoGobierno Autónomo Departamental de Santa CruzUniversidad Autónoma de SinaloaMuseu de Zoologia da Universidade de Sao Paulo (MZUSP)University of Freiburg Evolutionary Biology and Animal EcologyMuseu de História Natural Capão da ImbuiaFundação Neotropica do BrasilCEMAVE: Centro Nacional de Pesquisa para a Conservação das Aves SilvestresCORBIDIAsociación Fauna ForeverUniversity of San Francisco Xavier de ChuquisacaUniversidad Nacional Autónoma de México Museo de Zoología Facultad de CienciasU.S. Fish and Wildlife Service Puerto Rican Parrot Recovery ProgramEcho Parrots and PeopleCátedra de Ecología General y Recursos Naturales Universidad Nacional Arturo JauretcheFundación para la Investigación y Conservación de los Loros en Bolivia (CLB)Instituto de Bio y Geociencias del NOA CONICETLaboratorio Nacional de Análisis y Síntesis Ecológica Universidad Nacional Autónoma de MéxicoDepto. de Estudios Ambientales Universidad Simón BolívarUNESP Instituto de Biociências de BotucatuConsejo Nacional de Investigaciones Científicas y Técnicas: CONICET-PIP 112-201501-0598Agencia Nacional de Promoción Científica y Tecnológica: FONCyT-PICT 2015-228

    Current threats faced by Neotropical parrot populations

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    Berkunsky I, Quillfeldt P, Brightsmith DJ, et al. Current threats faced by Neotropical parrot populations. Biological Conservation. 2017;214:278-287.Psittaciformes (parrots, cockatoos) are among the most endangered birds, with 31% of Neotropical species under threat. The drivers of this situation appear to be manifold and mainly of anthropogenic origin. However, this assessment is based on the last extensive consultation about the conservation situation of parrots carried out in the 1990s. Given the rapid development of anthropogenic threats, updated data are needed to strategize conservation actions. Using a population approach, we addressed this need through a wide-ranging consultation involving biologists, wildlife managers, government agencies and non-governmental conservation organizations. We gathered up-to-date information on threats affecting 192 populations of 96 Neotropical parrot species across 21 countries. Moreover, we investigated associations among current threats and population trends. Many populations were affected by multiple threats. Agriculture, Capture for the Pet Trade, Logging, each of them affected > 55% of the populations, suggesting a higher degree of risk than previously thought. In contrast to previous studies at the species level, our study showed that the threat most closely associated with decreasing population trends is now Capture for the local Pet Trade. Other threats associated with decreasing populations include Small-holder Farming, Rural Population Pressure, Nest Destruction by Poachers, Agro-industry Grazing, Small-holder Grazing, and Capture for the international Pet Trade. Conservation actions have been implemented on < 20% of populations. Our results highlight the importance of a population-level approach in revealing the extent of threats to wild populations. It is critical to increase the scope of conservation actions to reduce the capture of wild parrots for pets

    Toward next-generation primate neuroscience: A collaboration-based strategic plan for integrative neuroimaging

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    Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently devel-oped a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience

    Rivaroxaban with or without aspirin in stable cardiovascular disease

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    BACKGROUND: We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. METHODS: In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after a mean follow-up of 23 months. RESULTS: The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; P<0.001; z=−4.126), but major bleeding events occurred in more patients in the rivaroxaban-plus-aspirin group (288 patients [3.1%] vs. 170 patients [1.9%]; hazard ratio, 1.70; 95% CI, 1.40 to 2.05; P<0.001). There was no significant difference in intracranial or fatal bleeding between these two groups. There were 313 deaths (3.4%) in the rivaroxaban-plus-aspirin group as compared with 378 (4.1%) in the aspirin-alone group (hazard ratio, 0.82; 95% CI, 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025). The primary outcome did not occur in significantly fewer patients in the rivaroxaban-alone group than in the aspirin-alone group, but major bleeding events occurred in more patients in the rivaroxaban-alone group. CONCLUSIONS: Among patients with stable atherosclerotic vascular disease, those assigned to rivaroxaban (2.5 mg twice daily) plus aspirin had better cardiovascular outcomes and more major bleeding events than those assigned to aspirin alone. Rivaroxaban (5 mg twice daily) alone did not result in better cardiovascular outcomes than aspirin alone and resulted in more major bleeding events
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