Livestock management and dam removal allowed the recovery of an aquatic habitat for endangered frog and fish species in Argentinian Patagonia

Fil: Arellano, María Luz. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Vertebrados; ArgentinaFil: Velasco, Melina Alicia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Vertebrados; ArgentinaFil: Quiroga, Sofía. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Kass, Camila Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Vertebrados; ArgentinaFil: Kass, Nicolas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Vertebrados; ArgentinaFil: Kacoliris, Federico Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Vertebrados; Argentin

Inventário da herpetofauna do Parque Nacional Talampaya, Patrimônio da Humanidade, na Argentina

Talampaya National Park (TNP) was designated a UNESCO World Heritage Site, together with Ischigualasto Provincial Park in 2000, but there is no list with updated information from reptiles and amphibians eighteen years after its creation. Therefore, we listed a complete inventory of the herpetofauna of TNP with the information obtained from bibliography, data from Argentina National Parks Administration (ranger reports and the species listed in their database) and fieldwork using pitfall traps, active search transects and pictures/material collected in the site. We confirm the occurrence of 35 species of herpetofauna in the TNP, including 29 reptiles and 6 amphibians. Some species found in TNP are of great value because their national conservation status is vulnerable (Chelonoidis chilensis, Liolaemus anomalus, Liolaemus riojanus) or even endangered (Boa constrictor occidentalis). Therefore, priority areas for conservation of these species should be proposed inside the park. Keywords: amphibians, conservation area, list of species, reptiles.O Parque Nacional Talampaya (TNP) foi declarado Patrimônio da Humanidade pela UNESCO, juntamente com o Parque Provincial Ischigualasto, em 2000, mas não há lista com informações atualizadas de répteis e anfíbios 18 anos após sua criação. Portanto, listamos um inventário completo da herpetofauna do TNP com as informações obtidas na bibliografia, dados da Administração de Parques Nacionais da Argentina (relatórios de guardas florestais e as espécies listadas em seu banco de dados) e trabalho de campo usando armadilhas de queda, transecções de pesquisa ativa e fotos/material coletado no site. Confirmamos a presença de 35 espécies da herpetofauna no TNP, incluindo 29 répteis e 6 anfíbios. Algumas espécies encontradas no TNP são de grande importância, pois seu estado de conservação nacional é vulnerável (Chelonoidis chilensis, Liolaemus anomalus, Liolaemus riojanus), ou mesmo em perigo (Boa constrictor occidentalis). Assim, áreas prioritárias para a conservação dessas espécies devem ser propostas para o parque.Palavras-chave: anfíbios, lista de espécies, répteis, unidade de conservação

Segundo encuentro de becarios y tesistas de la Facultad de Ciencias Naturales y Museo

El II Encuentro de Becarios/as y Tesistas de la FCNyM”, representa la continuación del “I EByT FCNyM” que fue realizado de forma virtual en el año 2020. Este encuentro es una iniciativa de becarios, becarias y tesistas doctorales con lugar de trabajo en la Facultad de Ciencias Naturales y Museo, y tiene el objetivo de generar un espacio permanente de diálogo y discusión. En esta nueva edición, realizada en forma híbrida (presencial y virtual) en el mes de octubre de 2022, se continuó con la visibilización de nuestro trabajo y con el intercambio de miradas y perspectivas. Asimismo, se extendió la invitación a participar a egresados/as recientes y a estudiantes de todas las carreras de posgrado de la FCNyM.El encuentro se dividió en tres módulos, cada uno con objetivos particulares. El primer módulo consistió en la exposición de temas de investigación y trabajos específicos que realicen los participantes, en este módulo se presentaron diez trabajos, que abarcaron temáticas de antropología, biología, paleontología y geología. El segundo módulo consistió en la exposición de dos conferencias magistrales, una relacionada a la salud mental de las personas tesistas o becadas, y otra relacionada al uso del software libre “R”. El último módulo consistió en un plenario donde se discutieron problemáticas que nos interpelan como doctorandos. Por lo anteriormente expresado, consideramos que este encuentro fue muy enriquecedor,fomentó la interacción entre pares y la interdisciplinariedad de quienes se encuentran transitando esta etapa fundamental de la formación profesional en investigación. El documento que se presenta es una compilación de los resúmenes de los trabajos y conferencias presentadas, junto con una breve síntesis gráfica de las exposiciones que tuvieron lugar durante la jornada. Agradecemos a todos su participación y compromiso.

Cytokine Combination Therapy with Erythropoietin and Granulocyte Colony Stimulating Factor in a Porcine Model of Acute Myocardial Infarction

PurposeErythropoietin (EPO) and granulocyte colony stimulating factor (GCSF) have generated interest as novel therapies after myocardial infarction (MI), but the effect of combination therapy has not been studied in the large animal model. We investigated the impact of prolonged combination therapy with EPO and GCSF on cardiac function, infarct size, and vascular density after MI in a porcine model.MethodsMI was induced in pigs by a 90 min balloon occlusion of the left anterior descending coronary artery. 16 animals were treated with EPO+GCSF, or saline (control group). Cardiac function was assessed by echocardiography and pressure-volume measurements at baseline, 1 and 6 weeks post-MI. Histopathology was performed 6 weeks post-MI.ResultsAt week 6, EPO+GCSF therapy stabilized left ventricular ejection fraction, (41 ± 1% vs. 33 ± 1%, p < 0.01) and improved diastolic function compared to the control group. Histopathology revealed increased areas of viable myocardium and vascular density in the EPO+GCSF therapy, compared to the control. Despite these encouraging results, in a historical analysis comparing combination therapy with monotherapy with EPO or GCSF, there were no significant additive benefits in the LVEF and volumes overtime using the combination therapy.ConclusionOur findings indicate that EPO+GCSF combination therapy promotes stabilization of cardiac function after acute MI. However, combination therapy does not seem to be superior to monotherapy with either EPO or GCSF

A simulation study on the effects of neuronal ensemble properties on decoding algorithms for intracortical brain-machine interfaces

Background: Intracortical brain-machine interfaces (BMIs) harness movement information by sensing neuronal activities using chronic microelectrode implants to restore lost functions to patients with paralysis. However, neuronal signals often vary over time, even within a day, forcing one to rebuild a BMI every time they operate it. The term "rebuild" means overall procedures for operating a BMI, such as decoder selection, decoder training, and decoder testing. It gives rise to a practical issue of what decoder should be built for a given neuronal ensemble. This study aims to address it by exploring how decoders' performance varies with the neuronal properties. To extensively explore a range of neuronal properties, we conduct a simulation study. Methods: Focusing on movement direction, we examine several basic neuronal properties, including the signal-to-noise ratio of neurons, the proportion of well-tuned neurons, the uniformity of their preferred directions (PDs), and the non-stationarity of PDs. We investigate the performance of three popular BMI decoders: Kalman filter, optimal linear estimator, and population vector algorithm. Results: Our simulation results showed that decoding performance of all the decoders was affected more by the proportion of well-tuned neurons that their uniformity. Conclusions: Our study suggests a simulated scenario of how to choose a decoder for intracortical BMIs in various neuronal conditions

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters