Abundância de enquitreídeos estimada por diferentes métodos de coleta e extração num fragmento de Floresta Ombrófila Mista no Paraná.

Enquitreídeos (Enchytraeidae, Oligochaeta) são organismos da mesofauna edáfica encontrados no mundo inteiro, mas ainda pouco estudados no Brasil. A abundância desses organismos determinada por diferentes métodos de coleta e extração, bem como as vantagens e desvantagens de cada método são apresentadas neste trabalho. Os métodos de amostragem com formol e por escavação de monólitos seguidos de triagem manual foram comparados aos métodos de coleta com trado desmontável seguido de extração úmida fria por três dias e extração úmida quente por três horas, que são recomendados para amostragens quantitativas de enquitreídeos. As coletas foram realizadas em 8-9 pontos num fragmento de floresta ombrófila mista em Colombo, PR, em 1-3 ocasiões entre setembro 2011 e abril 2012. O número médio de indivíduos encontrados por metro quadrado (ind./ m2) através de cada método foi de aproximadamente 5, 90, 2.000-12.000 e 5.000-12.000 respectivamente. Os métodos de coleta e extração originalmente usados para as minhocas, formol e monólitos subestimaram grandemente a abundância de enquitreídeos, pois na triagem manual, as espécies de tamanho menor são ignoradas. Como esperado, a coleta com trado desmontável seguida de extração úmida é a mais adequada para estudos quantitativos de enquitreídeos, porém, a extração quente, além de ser mais rápida, causa menos dano aos espécimes coletados facilitando o processo de identificação taxonômica que deve ser feito in vivo. O número máximo obtido nesse estudo foi de aproximadamente 44.000 ind./ m2, um dos maiores valores relatados até hoje no Brasil.Resumo expandido

Systemic Risk and Default Clustering for Large Financial Systems

As it is known in the finance risk and macroeconomics literature, risk-sharing in large portfolios may increase the probability of creation of default clusters and of systemic risk. We review recent developments on mathematical and computational tools for the quantification of such phenomena. Limiting analysis such as law of large numbers and central limit theorems allow to approximate the distribution in large systems and study quantities such as the loss distribution in large portfolios. Large deviations analysis allow us to study the tail of the loss distribution and to identify pathways to default clustering. Sensitivity analysis allows to understand the most likely ways in which different effects, such as contagion and systematic risks, combine to lead to large default rates. Such results could give useful insights into how to optimally safeguard against such events.Comment: in Large Deviations and Asymptotic Methods in Finance, (Editors: P. Friz, J. Gatheral, A. Gulisashvili, A. Jacqier, J. Teichmann) , Springer Proceedings in Mathematics and Statistics, Vol. 110 2015

Sporormiella as a tool for detecting the presence of large herbivores in the Neotropics

The reliability of using the abundance of Sporormiella spores as a proxy for the presence and abundance of megaherbivores was tested in southern Brazil. Mud-water interface samples from nine lakes, in which cattle-use was categorized as high, medium, or low, were assayed for Sporormiella representation. The sampling design allowed an analysis of both the influence of the number of animals using the shoreline and the distance of the sampling site from the nearest shoreline. Sporormiella was found to be a reliable proxy for the presence of large livestock. The concentration and abundance of spores declined from the edge of the lake toward the center, with the strongest response being in sites with high livestock use. Consistent with prior studies in temperate regions, we find that Sporormiella spores are a useful proxy to study the extinction of Pleistocene megafauna or the arrival of European livestock in Neotropical landscapes

Effective connectivity reveals strategy differences in an expert calculator

Mathematical reasoning is a core component of cognition and the study of experts defines the upper limits of human cognitive abilities, which is why we are fascinated by peak performers, such as chess masters and mental calculators. Here, we investigated the neural bases of calendrical skills, i.e. the ability to rapidly identify the weekday of a particular date, in a gifted mental calculator who does not fall in the autistic spectrum, using functional MRI. Graph-based mapping of effective connectivity, but not univariate analysis, revealed distinct anatomical location of “cortical hubs” supporting the processing of well-practiced close dates and less-practiced remote dates: the former engaged predominantly occipital and medial temporal areas, whereas the latter were associated mainly with prefrontal, orbitofrontal and anterior cingulate connectivity. These results point to the effect of extensive practice on the development of expertise and long term working memory, and demonstrate the role of frontal networks in supporting performance on less practiced calculations, which incur additional processing demands. Through the example of calendrical skills, our results demonstrate that the ability to perform complex calculations is initially supported by extensive attentional and strategic resources, which, as expertise develops, are gradually replaced by access to long term working memory for familiar material

Marginalization of end-use technologies in energy innovation for climate protection

Mitigating climate change requires directed innovation efforts to develop and deploy energy technologies. Innovation activities are directed towards the outcome of climate protection by public institutions, policies and resources that in turn shape market behaviour. We analyse diverse indicators of activity throughout the innovation system to assess these efforts. We find efficient end-use technologies contribute large potential emission reductions and provide higher social returns on investment than energy-supply technologies. Yet public institutions, policies and financial resources pervasively privilege energy-supply technologies. Directed innovation efforts are strikingly misaligned with the needs of an emissions-constrained world. Significantly greater effort is needed to develop the full potential of efficient end-use technologies

Growth and nutrition in children with Ataxia telangiectasia

Background: Ataxia telangiectasia (A-T) is a rare multisystem disease with high early mortality from lung disease and cancer. Nutritional failure adversely impacts outcomes in many respiratory diseases. Several factors influence nutrition in children with A-T. We hypothesised that children with A-T have progressive growth failure and that early gastrostomy tube feeding (percutaneous endoscopic gastrostomy, or PEG) is a favourable management option with good nutritional outcomes. Methods: Data were collected prospectively on weight, height and body mass index (BMI) at the national paediatric A-T clinic. Adequacy and safety of oral intake was assessed. Nutritional advice was given at each multidisciplinary review. Results: 101 children (51 girls) had 222 measurements (32 once, 32 twice, 24 thrice) between 2009 and 2016. Median (range) age was 9.3 (1.5 to 18.4) years. Mean (sd) weight, height and BMI Z-scores were respectively -1.03(1.57), -1.17 (1.18) and -0.36 (1.43). 35/101 children had weight Z-scores below -2 on at least one occasion. Weight, height and BMI Z-scores declined over time. Decline was most obvious after 8 years of age. 14/101 (13.9%) children had a PEG, with longitudinal data available for 12. In a nested case control study, there was a trend for improvement in weight in those with a PEG (p = 0.06). Conclusions: A-T patients decline in growth over time. There is an urgent need for new strategies, including an understanding of why growth falters. We suggest early proactive consideration of PEG from age 8 years onwards in order to prevent progressive growth failure

On encoding symbol degrees of array BP-XOR codes

Low density parity check (LDPC) codes, LT codes and digital fountain techniques have received significant attention from both academics and industry in the past few years. By employing the underlying ideas of efficient Belief Propagation (BP) decoding process (also called iterative message passing decoding process) on binary erasure channels (BEC) in LDPC codes, Wang has recently introduced the concept of array BP-XOR codes and showed the necessary and sufficient conditions for MDS [k + 2,k] and [n,2] array BP-XOR codes. In this paper, we analyze the encoding symbol degree requirements for array BP-XOR codes and present new necessary conditions for array BP-XOR codes. These new necessary conditions are used as a guideline for constructing several array BP-XOR codes and for presenting a complete characterization (necessary and sufficient conditions) of degree two array BP-XOR codes and for designing new edge-colored graphs. Meanwhile, these new necessary conditions are used to show that the codes by Feng, Deng, Bao, and Shen in IEEE Transactions on Computers are incorrect

Evaluating major curriculum change:the effect on student confidence

Aim: The aim of this study was to evaluate the effect of major curriculum change within a UK dental school on final-year student self-rated confidence levels. Methods: Final-year dental students graduating in each year between 2007 and 2012 completed the same course evaluation questionnaire, which assessed their confidence in relation to a range of clinical procedures using a Likert-type scale. This period spanned the introduction of a new curriculum and allowed analysis of differences in self-rated confidence between students graduating from the old (2007 and 2008) and new (2009–2012) curricula, across thirty key procedures. Results: New curriculum students showed significantly higher self-confidence ratings in nineteen of the thirty procedures, compared with those on the old curriculum. For the remaining eleven procedures there was no significant difference between the two curricula. The proportion of students on the outcomes-based curriculum rating themselves as 'confident” was statistically significantly higher in seven out of the thirty procedures, when compared with the traditional curriculum, and unchanged or nonsignificantly increased in the remainder. Discussion and conclusions: The relationship between specific curricular innovations and student confidence is considered, as is the usefulness of self-rated confidence in curriculum evaluation. Curriculum change appeared to have a positive effect on student confidence across a range of procedures

Localized microstimulation of primate pregenual cingulate cortex induces negative decision-making

The pregenual anterior cingulate cortex (pACC) has been implicated in human anxiety disorders and depression, but the circuit-level mechanisms underlying these disorders are unclear. In healthy individuals, the pACC is involved in cost-benefit evaluation. We developed a macaque version of an approach-avoidance decision task used to evaluate anxiety and depression in humans and, with multi-electrode recording and cortical microstimulation, we probed pACC function as monkeys performed this task. We found that the macaque pACC has an opponent process-like organization of neurons representing motivationally positive and negative subjective value. Spatial distribution of these two neuronal populations overlapped in the pACC, except in one subzone, where neurons with negative coding were more numerous. Notably, microstimulation in this subzone, but not elsewhere in the pACC, increased negative decision-making, and this negative biasing was blocked by anti-anxiety drug treatment. This cortical zone could be critical for regulating negative emotional valence and anxiety in decision-making.National Institutes of Health (U.S.) (Javits Merit Grant R01 NS025529)United States. Office of Naval Research (N000140710903)National Parkinson Foundation (U.S.) (Lynn Diamond Fellowship

How to distinguish starbursts and quiescently star-forming galaxies: The `bimodal' submillimetre galaxy population as a case study

In recent work (arXiv:1101.0002) we have suggested that the high-redshift (z ~ 2-4) bright submillimetre galaxy (SMG) population is heterogeneous, with major mergers contributing both at early stages, where quiescently star-forming discs are blended into one submm source (`galaxy-pair SMGs'), and late stages, where mutual tidal torques drive gas inflows and cause strong starbursts. Here we combine hydrodynamic simulations of major mergers with 3-D dust radiative transfer calculations to determine observational diagnostics that can distinguish between quiescently star-forming SMGs and starburst SMGs via integrated data alone. We fit the far-IR SEDs of the simulated galaxies with the optically thin single-temperature modified blackbody, the full form of the single-temperature modified blackbody, and a power-law temperature-distribution model. The effective dust temperature, T_dust, and power-law index of the dust emissivity in the far-IR, \beta, derived can significantly depend on the fitting form used, and the intrinsic \beta\ of the dust is not recovered. However, for all forms used here, there is a T_dust above which almost all simulated galaxies are starbursts, so a T_dust cut is very effective at selecting starbursts. Simulated merger-induced starbursts also have higher L_IR/M_gas and L_IR/L_FUV than quiescently star-forming galaxies and lie above the star formation rate-stellar mass relation. These diagnostics can be used to test our claim that the SMG population is heterogeneous and to observationally determine what star formation mode dominates a given galaxy population. We comment on applicability of these diagnostics to ULIRGs that would not be selected as SMGs. These `hot-dust ULIRGs' are typically starburst galaxies lower in mass than SMGs, but they can also simply be SMGs observed from a different viewing angle.Comment: 21 pages, 11 figures. Accepted for publication in MNRAS. Minor changes to text but otherwise identical to v