Are we selecting appropriate metrics to assess human impacts on biodiversity?

Biased and subjective choices in the variable selection processes used in ecological studies commonly lead researchers to reach misleading conclusions regarding patterns of biodiversity response to disturbances. Nevertheless, little attention has been given to these processes in the majority of studies published to date. Here, we assess the extent to which variables commonly employed in ecological studies correspond to those deemed to be most important by researchers of the same studies. Specifically, we examined both biodiversity (response) and environmental (explanatory) metrics from a comprehensive literature review and compared their use with their relative importance, according to a survey with the studies’ authors. We used the literature concerning land use change effects on dung beetles as our study case. Our results highlight marked disparities between researchers opinion and their choice of variables in published papers. We suggest that these disparities are due to the high costs of sampling and processing some variables, as well as to logistical constraints and researchers own bias. If current practices and these discrepancies persist then our understanding of the biodiversity consequences of land-use change will remain compromised, while further undermining our confidence in the results of ecological studies

Relato de caso de miastenia grave infantil / Case report of serious child miastenia

 Introdução : A Miastenia Grave ou Myasthenia Gravis ( MG ) é uma doença autoimune da junção neuromuscular na qual ocorre a produção de anticorpos que atuam contra os receptores nicotínicos da acetilcolina, localizados na membrana pós - sináptica da placa motora. Foi internado no Instituto da Saúde da Criança do Amazonas - ICAM com o quadro estável. Mantém as pálpebras semiabertas pela manhã, mas evolui com ptose palpebral e fadiga proeminentes ao final do dia. Ptose palpebral bilateral. Hipótese diagnóstica : Miastenia Grave. Resultados : Eletroneuromiografia compatível com Miastenia Grave de 06/10/2017 e Tomografia Computadorizada de Tórax com imagem nodular sugestivo de sombra tímica de 17/11/2017. Conclusão : A Miastenia Grave deve ser encarada como um problema de saúde pública, a investigação deve avançar na tentativa de se encontrar uma solução eficaz, segura, com um perfil de efeitos adversos favorável, que corrija especificamente as alterações imunitárias causadoras da doença, sem comprometer o restante sistema imunitário.

How pervasive is biotic homogenization in human‐modified tropical forest landscapes?

Land-cover change and ecosystem degradation may lead to biotic homogenization, yet our understanding of this phenomenon over large spatial scales and different biotic groups remains weak. We used a multi-taxa dataset from 335 sites and 36 heterogeneous landscapes in the Brazilian Amazon to examine the potential for landscape-scale processes to modulate the cumulative effects of local disturbances. Biotic homogenization was high in production areas but much less in disturbed and regenerating forests, where high levels of among-site and among-landscape β-diversity appeared to attenuate species loss at larger scales. We found consistently high levels of β-diversity among landscapes for all land cover classes, providing support for landscape-scale divergence in species composition. Our findings support concerns that β-diversity has been underestimated as a driver of biodiversity change and underscore the importance of maintaining a distributed network of reserves, including remaining areas of undisturbed primary forest, but also disturbed and regenerating forests, to conserve regional biota

Anthropogenic disturbance in tropical forests can double biodiversity loss from deforestation

© 2016 Macmillan Publishers Limited. All rights reserved. Concerted political attention has focused on reducing deforestation, and this remains the cornerstone of most biodiversity conservation strategies. However, maintaining forest cover may not reduce anthropogenic forest disturbances, which are rarely considered in conservation programmes. These disturbances occur both within forests, including selective logging and wildfires, and at the landscape level, through edge, area and isolation effects. Until now, the combined effect of anthropogenic disturbance on the conservation value of remnant primary forests has remained unknown, making it impossible to assess the relative importance of forest disturbance and forest loss. Here we address these knowledge gaps using a large data set of plants, birds and dung beetles (1,538, 460 and 156 species, respectively) sampled in 36 catchments in the Brazilian state of Pará. Catchments retaining more than 69-80% forest cover lost more conservation value from disturbance than from forest loss. For example, a 20% loss of primary forest, the maximum level of deforestation allowed on Amazonian properties under Brazil's Forest Code, resulted in a 39-54% loss of conservation value: 96-171% more than expected without considering disturbance effects. We extrapolated the disturbance-mediated loss of conservation value throughout Pará, which covers 25% of the Brazilian Amazon. Although disturbed forests retained considerable conservation value compared with deforested areas, the toll of disturbance outside Pará's strictly protected areas is equivalent to the loss of 92,000-139,000 km2 of primary forest. Even this lowest estimate is greater than the area deforested across the entire Brazilian Amazon between 2006 and 2015 (ref. 10). Species distribution models showed that both landscape and within-forest disturbances contributed to biodiversity loss, with the greatest negative effects on species of high conservation and functional value. These results demonstrate an urgent need for policy interventions that go beyond the maintenance of forest cover to safeguard the hyper-diversity of tropical forest ecosystems

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Search for a light pseudoscalar Higgs boson in the boosted mu mu tau tau final state in proton-proton collisions at root s=13 TeV

A search for a light pseudoscalar Higgs boson (a) decaying from the 125 GeV (or a heavier) scalar Higgs boson (H) is performed using the 2016 LHC proton-proton collision data at root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), collected by the CMS experiment. The analysis considers gluon fusion and vector boson fusion production of the H, followed by the decay H -> aa -> mu mu tau tau, and considers pseudoscalar masses in the range 3.6 aa -> mu mu tau tau, down to 1.5 (2.0)x10(-4) for m(H) = 125 (300) GeV. Model-dependent limits on B(H -> aa) are set within the context of two Higgs doublets plus singlet models, with the most stringent results obtained for Type-III models. These results extend current LHC searches for heavier a bosons that decay to resolved lepton pairs and provide the first such bounds for an H boson with a mass above 125 GeV.Peer reviewe