Nitrogen Deposition Effects on Soil Properties, Microbial Abundance, and Litter Decomposition Across Three Shrublands Ecosystems From the Mediterranean Basin

Atmospheric nitrogen (N) inputs in the Mediterranean Basin are projected to increase due to fossil fuel combustion, fertilizer use, and the exacerbation of agricultural production processes. Although increasing N deposition is recognized as a major threat to ecosystem functioning, little is known about how local environmental conditions modulate ecosystem function response to N addition, particularly in the context of Mediterranean-Basin ecosystems. Here, we assess how N addition affects important ecosystem properties associated with litter decomposition, soil physical-chemical properties, soil extracellular enzymatic activity and microbial abundance across three long-term N addition experimental sites in the Mediterranean Basin. Sites were located in El Regajal (Madrid, Spain), Capo Caccia (Alghero, Italy), and Arrábida (Lisbon, Portugal) and are all representative of Mediterranean shrublands. No common pattern for litter decomposition process or other studied variables emerged among the control plots of the studied sites. Nitrogen supply only affected soil pH, a major driver of decomposition, in two out of three experimental sites. Moreover, when we explored the role of N addition and soil pH in controlling litter decay, we found that the effects of these factors were site-dependent. Our results point out to local ecosystem features modulating N addition effects in controlling litter decomposition rates in Mediterranean ecosystems, suggesting that the responses of soil functioning to N deposition are site-dependent. These findings provide further knowledge to understand contrasting ecosystem responses to N additions based on a single field experiments

Nitrogen addition drives decomposition rates in Mediterranean ecosystems via changes in soil properties and microbial attributes

Abstract de la comunicación oral presentada en 20th EGU General Assembly, EGU2018, Proceedings from the conference held 4-13 April, 2018 in Vienna, Austria, p.14022.- Enlace online https://ui.adsabs.harvard.edu/abs/2018EGUGA..2014022M/abstractAlthough anthropogenic nitrogen (N) deposition has been identified as a major threat to biodiversity and ecosystem functioning in Mediterranean environments, little is known on the role of soil properties and microbial attributes in mediating the response of soil organic matter (SOM) decomposition to N inputs. Here, we used Structural Equation Modeling (SEM) to evaluate the direct and indirect effects of N inputs on SOM decomposition rates across different N loads and three Mediterranean semi-arid ecosystems. Our SEM showed that soil ammonium availability decreases soil pH leading to a reduction of the fungi/bacteria ratio and to an increase in soil enzymatic activity, whereas it also has a negative direct and mayor effect on soil decomposition rate. This increase in soil enzymatic activity, which was conditioned not only by soil pH but also by the fungi/bacteria ratio and inorganic N content, had a positive direct effect on the soil decomposition rate. Together, our results suggest that changes in soil properties and microbial attributes linked to N additions can affect the SOM decomposition rates across three regions from the Mediterranean Basin. These findings improve our understanding of the links between soil chemical properties, microbial communities and function in Mediterranean ecosystems, especially in the context of anthropogenic N enrichment.N

Finding benchmark brown dwarfs to probe the IMF as a function of time

Using a simulated disk brown dwarf (BD) population, we find that new large area infrared surveys are expected to identify enough BDs covering wide enough mass--age ranges to potentially measure the mass function down to ~0.03Mo, and the BD formation history out to 10 Gyr, at a level capable of establishing if BD formation follows star formation. We suggest these capabilities are best realised by spectroscopic calibration of BD properties (Teff, g and [M/H]) which, when combined with a measured luminosity and an evolutionary model can give BD mass and age relatively independent of BD atmosphere models. Such calibration requires an empirical understanding of how BD spectra are affected by variations in these properties, and thus the identification and study of "benchmark BDs" whose age and composition can be established independently. We identify the best sources of benchmark BDs as young open cluster members, moving group members, and wide (>1000AU) BD companions to both subgiant stars and high mass white dwarfs (WDs). We have used 2MASS to measure a wide L dwarf companion fraction of 2.7(+0.7/-0.5)%, which equates to a BD companion fraction of 34(+9/-6)% for an alpha~1 companion mass function. Using this value we simulate populations of wide BD binaries, and estimate that 80(+21/-14) subgiant--BD binaries, and 50(+13/-10) benchmark WD--BD binaries could be identified using current and new facilities. The WD--BD binaries should all be identifiable using the Large Area Survey component of UKIDSS combined with Sloan. Discovery of the subgiant--BD binaries will require a NIR imaging campaign around a large (~900) sample of Hipparcos subgiants. If identified, spectral studies of these benchmark brown dwarfs could reveal the spectral sensitivities across the Teff, g and [M/H] space probed by new surveys.Comment: 18 pages, 12 figures, accepted for publication in MNRA

Complicações dos portadores de lesões traumato- ortopédicas das vítimas de acidente motociclístico / Complications of traumate-orthopedic injury holders of motocyclistic accident victims

Introdução: O índice de lesões traumáticas incapacitantes decorrentes a acidentes motociclísticos vem aumentando continuamente, caracterizando-se assim um problema grave de saúde pública, pois seus efeitos implicam na elevada demanda de leitos hospitalares, incapacidade física temporária ou definitiva das vítimas e até mesmo o óbito. Objetivo: O presente estudo teve como objetivo avaliar as complicações dos portadores de lesões traumato-ortopédicas das vítimas de acidente motociclístico. Métodos: Foi realizada uma pesquisa de natureza exploratória e descritiva, através de abordagem quantitativa, no setor de ortopedia e traumatologia do Hospital Otávio de Freitas na cidade do Recife. Foi aprovado pelo Comitê de Ética e Pesquisa, e também houve a autorização da instituição pesquisada. Utilizou-se como instrumento de coleta de dados dois questionários estruturados com questões fechadas e abertas, onde foi captada uma amostra de 80 pacientes vítimas de acidente motociclístico. Resultados: Observou-se que a faixa etária prevalente das vítimas é de 18 a 30 anos, equivalente a 52,5%, sendo 95% do sexo masculino, o que corresponde a 76 entrevistados. A maioria possuía apenas o ensino fundamental II completo, o que representa 45%. Dos pesquisados, em relação ao tipo de colisão, prevalece aquelas envolvidas com carro, ônibus ou caminhão, o que corresponde a 50%. No que diz respeito às complicações pós-traumáticas, 95% das vítimas apresentaram dor apesar do uso de medicações prescritas para controle, 94% apresentaram incapacidade funcional e 78% desenvolveram lesões infectadas, o que contribui para complicações crônicas como osteomielite, aumentando o período de internação. Conclusão: Este estudo permitiu o conhecimento do perfil epidemiológico dos pacientes, bem como as complicações desenvolvidas após o acidente, interferindo na qualidade de vida dos mesmos. A identificação dessas particularidades proporciona ao enfermeiro planejar sua assistência possiblitando o planejamento do cuidado especializado a essas vítimas, e implementando ações que visem a diminuição das complicações com o objetivo de auxiliar na recuperação precoce dos pacientes.

Nitrogen deposition effects on soil properties, microbial abundance, and litter decomposition across three shrublands ecosystems from the Mediterranean Basin

Atmospheric nitrogen (N) inputs in the Mediterranean Basin are projected to increase due to fossil fuel combustion, fertilizer use, and the exacerbation of agricultural production processes. Although increasing N deposition is recognized as a major threat to ecosystem functioning, little is known about how local environmental conditions modulate ecosystem function response to N addition, particularly in the context of Mediterranean-Basin ecosystems. Here, we assess how N addition affects important ecosystem properties associated with litter decomposition, soil physical-chemical properties, soil extracellular enzymatic activity and microbial abundance across three long-term N addition experimental sites in the Mediterranean Basin. Sites were located in El Regajal (Madrid, Spain), Capo Caccia (Alghero, Italy), and Arrábida (Lisbon, Portugal) and are all representative of Mediterranean shrublands. No common pattern for litter decomposition process or other studied variables emerged among the control plots of the studied sites. Nitrogen supply only affected soil pH, a major driver of decomposition, in two out of three experimental sites. Moreover, when we explored the role of N addition and soil pH in controlling litter decay, we found that the effects of these factors were site-dependent. Our results point out to local ecosystem features modulating N addition effects in controlling litter decomposition rates in Mediterranean ecosystems, suggesting that the responses of soil functioning to N deposition are sitedependent. These findings provide further knowledge to understand contrasting ecosystem responses to N additions based on a single field experiments

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

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson