1,068 research outputs found

    Multinational tagging efforts illustrate regional scale of distribution and threats for east pacific green turtles (Chelonia mydas agassizii).

    Get PDF
    Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from Public Library of Science via the DOI in this record.To further describe movement patterns and distribution of East Pacific green turtles (Chelonia mydas agassizii) and to determine threat levels for this species within the Eastern Pacific. In order to do this we combined published data from existing flipper tagging and early satellite tracking studies with data from an additional 12 satellite tracked green turtles (1996-2006). Three of these were tracked from their foraging grounds in the Gulf of California along the east coast of the Baja California peninsula to their breeding grounds in Michoacán (1337-2928 km). In addition, three post-nesting females were satellite tracked from Colola beach, Michoacán to their foraging grounds in southern Mexico and Central America (941.3-3020 km). A further six turtles were tracked in the Gulf of California within their foraging grounds giving insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Turtles tracked within foraging grounds showed that foraging individuals typically ranged up to 691.6 km (maximum) from release site location. Additionally, we carried out threat analysis (using the cumulative global human impact in the Eastern Pacific) clustering pre-existing satellite tracking studies from Galapagos, Costa Rica, and data obtained from this study; this indicated that turtles foraging and nesting in Central American waters are subject to the highest anthropogenic impact. Considering that turtles from all three rookeries were found to migrate towards Central America, it is highly important to implement conservation plans in Central American coastal areas to ensure the survival of the remaining green turtles in the Eastern Pacific. Finally, by combining satellite tracking data from this and previous studies, and data of tag returns we created the best available distributional patterns for this particular sea turtle species, which emphasized that conservation measures in key areas may have positive consequences on a regional scale.The work was supported by Earthwatch Institute, David and Lucile Packard Foundation, Wallace Research Foundation, PADI Foundation and the Arizona-Sonora Desert Museum. C. E. H. received a Masters degree bursary from the University of Exeter and the European Social Fund and would like to thank Consejo Nacional de Ciencia y Tecnología (Mexico) for support through a PhD scholarship. W. J. N. was supported by a Fulbright Fellowship and a Marshall Fellowship during the period field research in Baja California was conducted. B. J. G. is supported by the Darwin Initiative, European Social Fund and The Natural Environment Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    La formación del profesorado de ciencias de nivel medio superior en la provincia de México

    Get PDF
    El presente trabajo muestra los programas de formación docente de educación en ciencias que la Coordinación de Formación Docente de la Secretaría de Extensión Académica de la Facultad de Química de la Universidad Nacional Autónoma de México ofrece a los profesores de nivel medio superior de los diferentes estados de la República Mexicana con la finalidad de contribuir a mejorar la calidad de la enseñanza y del aprendizaje. Los programas están organizados en diplomados de 180 horas de clase, que constan de una conferencia inaugural motivacional, 8 módulos y una presentación de trabajos finales donde se aplican los conocimientos disciplinares y los enfoques pedagógico-didácticos y socio-filosófico aprendidos en el Diplomado

    Spinal neurons bursting in phase with fictive scratching are not related to spontaneous cord dorsum potentials

    Get PDF
    Spontaneous cord dorsum potentials (spontaneous CDPs) are produced by the activation of dorsal horn neurons distributed along the L4 to S1 spinal cord segments, in Rexed's laminae III-VI, in the same region in which there are interneurons rhythmically bursting during fictive scratching in cats. An interesting observation is that spontaneous CDPs are not rhythmically superimposed on the sinusoidal CDPs generated during fictive scratching episodes, thus suggesting that the interneurons producing both types of CDPs belong to different spinal circuits. In order to provide experimental data to support this hypothesis, we recorded unitary activity of neurons in the L6 spinal cord segment. We found that the neurons firing rhythmically during the sinusoidal CDPs associated with the extensor, flexor or intermediate phases of scratching were not synchronized with the spontaneous CDPs. Moreover, we found that the neurons firing during the spontaneous CDPs were not synchronized with the sinusoidal CDPs. These results suggest that the neurons involved in the occurrence of spontaneous CDPs are not part of the spinal cord central pattern generators (CPGs). This study will be relevant for understanding the relationships between the spinal cord neuronal populations firing spontaneously and the CPGs, in the intact and injured spinal cord. © 2014 IBRO

    Control of Visceral Leishmaniasis in Latin America—A Systematic Review

    Get PDF
    Visceral leishmaniasis is a vector-borne disease characterized by fever, spleen and liver enlargement, and low blood cell counts. In the Americas VL is zoonotic, with domestic dogs as main animal reservoirs, and is caused by the intracellular parasite Leishmania infantum (syn. Leishmania chagasi). Humans acquire the infection through the bite of an infected sand fly. The disease is potentially lethal if untreated. VL is reported from Mexico to Argentina, with recent trends showing a rapid spread in Brazil. Control measures directed against the canine reservoir and insect vectors have been unsuccessful, and early detection and treatment of human cases remains as the most important strategy to reduce case fatality. Well-designed studies evaluating diagnosis, treatment, and prevention/control interventions are scarce. The available scientific evidence reasonably supports the use of rapid diagnostic tests for the diagnosis of human disease. Properly designed randomized controlled trials following good clinical practices are needed to inform drug policy. Routine control strategies against the canine reservoirs and insect vectors are based on weak and conflicting evidence, and vector control strategies and vaccine development should constitute research priorities

    Search for resonances in the mass spectrum of muon pairs produced in association with b quark jets in proton-proton collisions at root 8 and 13 TeV

    Get PDF
    A search for resonances in the mass range 12-70 GeV produced in association with a b quark jet and a second jet, and decaying to a muon pair, is reported. The analysis is based on data from proton-proton collisions at center-of-mass energies of 8 and 13 TeV, collected with the CMS detector at the LHC and corresponding to integrated luminosities of 19.7 and 35.9 fb(-1), respectively. The search is carried out in two mutually exclusive event categories. Events in the first category are required to have a b quark jet in the central region (|| 2.4) and at least one jet in the forward region (|| > 2.4). Events in the second category are required to have two jets in the central region, at least one of which is identified as a b quark jet, no jets in the forward region, and low missing transverse momentum. An excess of events above the background near a dimuon mass of 28 GeV is observed in the 8 TeV data, corresponding to local significances of 4.2 and 2.9 standard deviations for the first and second event categories, respectively. A similar analysis conducted with the 13 TeV data results in a mild excess over the background in the first event category corresponding to a local significance of 2.0 standard deviations, while the second category results in a 1.4 standard deviation deficit. The fiducial cross section measurements and 95% confidence level upper limits on those for a resonance consistent with the 8 TeV excess are provided at both collision energies

    Search for supersymmetry in proton-proton collisions at 13 TeV using identified top quarks

    Get PDF
    A search for supersymmetry is presented based on proton-proton collision events containing identified hadronically decaying top quarks, no leptons, and an imbalance p(T)(miss) in transverse momentum. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). Search regions are defined in terms of the multiplicity of bottom quark jet and top quark candidates, the p(T)(miss) , the scalar sum of jet transverse momenta, and themT2 mass variable. No statistically significant excess of events is observed relative to the expectation from the standard model. Lower limits on the masses of supersymmetric particles are determined at 95% confidence level in the context of simplified models with top quark production. For a model with direct top squark pair production followed by the decay of each top squark to a top quark and a neutralino, top squark masses up to 1020 GeVand neutralino masses up to 430 GeVare excluded. For amodel with pair production of gluinos followed by the decay of each gluino to a top quark-antiquark pair and a neutralino, gluino masses up to 2040 GeVand neutralino masses up to 1150 GeVare excluded. These limits extend previous results.Peer reviewe

    Pseudorapidity distributions of charged hadrons in proton-lead collisions at root s(NN)=5:02 and 8.16 TeV

    Get PDF
    The pseudorapidity distributions of charged hadrons in proton-lead collisions at nucleon-nucleon center-of-mass energies root s(NN) = 5.02 and 8.16 TeV are presented. The measurements are based on data samples collected by the CMS experiment at the LHC. The number of primary charged hadrons produced in non-single-diffractive proton-lead collisions is determined in the pseudorapidity range vertical bar eta(lab)vertical bar vertical bar(vertical bar eta cm vertical bar) <0.5 are 17.1 +/- 0.01 (stat) +/- 0.59 (syst) and 20.10 +/- 0.01 (stat) +/- 0.5(syst) at root s(NN) = 5.02 and 8.16 TeV, respectively. The particle densities per participant nucleon are compared to similar measurements in proton-proton, proton-nucleus, and nucleus-nucleus collisions.Peer reviewe

    Search for Evidence of the Type-III Seesaw Mechanism in Multilepton Final States in Proton-Proton Collisions at root s=13 TeV

    Get PDF
    Peer reviewe

    Search for a light pseudoscalar Higgs boson produced in association with bottom quarks in pp collisions at root s=8 TeV

    Get PDF
    Peer reviewe

    Measurement of vector boson scattering and constraints on anomalous quartic couplings from events with four leptons and two jets in proton-proton collisions at root s=13 TeV

    Get PDF
    Peer reviewe
    corecore