Multi-responsive hydrogels based on N-isopropylacrylamide and sodium alginate

Hydrogels consisting of sodium alginate and N-isopropylacrylamide covalently crosslinked with N,N′-methylenebisacrylamide were prepared. The mixed-interpenetrated networks obtained were characterized using elemental analysis, Fourier transform infrared and Raman spectroscopy, swelling measurements and environmental scanning electron microscopy. The thermo- and pH-responsive properties of these hydrogels were evidenced by their swelling behaviour, which depended also on the amount of crosslinking agent and hydrogel composition.

A genome-wide association meta-analysis identifies new childhood obesity loci

Multiple genetic variants have been associated with adult obesity and a few with severe obesity in childhood; however, less progress has been made in establishing genetic influences on common early-onset obesity. We performed a North American, Australian and European collaborative meta-analysis of 14 studies consisting of 5,530 cases (≥95th percentile of body mass index (BMI)) and 8,318 controls (<50th percentile of BMI) of European ancestry. Taking forward the eight newly discovered signals yielding association with P < 5 × 10(-6) in nine independent data sets (2,818 cases and 4,083 controls), we observed two loci that yielded genome-wide significant combined P values near OLFM4 at 13q14 (rs9568856; P = 1.82 × 10(-9); odds ratio (OR) = 1.22) and within HOXB5 at 17q21 (rs9299; P = 3.54 × 10(-9); OR = 1.14). Both loci continued to show association when two extreme childhood obesity cohorts were included (2,214 cases and 2,674 controls). These two loci also yielded directionally consistent associations in a previous meta-analysis of adult BMI(1).

Meta-analysis of the INSIG2 association with obesity including 74,345 individuals: does heterogeneity of estimates relate to study design?

The INSIG2 rs7566605 polymorphism was identified for obesity (BMI> or =30 kg/m(2)) in one of the first genome-wide association studies, but replications were inconsistent. We collected statistics from 34 studies (n = 74,345), including general population (GP) studies, population-based studies with subjects selected for conditions related to a better health status ('healthy population', HP), and obesity studies (OB). We tested five hypotheses to explore potential sources of heterogeneity. The meta-analysis of 27 studies on Caucasian adults (n = 66,213) combining the different study designs did not support overall association of the CC-genotype with obesity, yielding an odds ratio (OR) of 1.05 (p-value = 0.27). The I(2) measure of 41% (p-value = 0.015) indicated between-study heterogeneity. Restricting to GP studies resulted in a declined I(2) measure of 11% (p-value = 0.33) and an OR of 1.10 (p-value = 0.015). Regarding the five hypotheses, our data showed (a) some difference between GP and HP studies (p-value = 0.012) and (b) an association in extreme comparisons (BMI> or =32.5, 35.0, 37.5, 40.0 kg/m(2) versus BMI<25 kg/m(2)) yielding ORs of 1.16, 1.18, 1.22, or 1.27 (p-values 0.001 to 0.003), which was also underscored by significantly increased CC-genotype frequencies across BMI categories (10.4% to 12.5%, p-value for trend = 0.0002). We did not find evidence for differential ORs (c) among studies with higher than average obesity prevalence compared to lower, (d) among studies with BMI assessment after the year 2000 compared to those before, or (e) among studies from older populations compared to younger. Analysis of non-Caucasian adults (n = 4889) or children (n = 3243) yielded ORs of 1.01 (p-value = 0.94) or 1.15 (p-value = 0.22), respectively. There was no evidence for overall association of the rs7566605 polymorphism with obesity. Our data suggested an association with extreme degrees of obesity, and consequently heterogeneous effects from different study designs may mask an underlying association when unaccounted for. The importance of study design might be under-recognized in gene discovery and association replication so far.

Six new loci associated with body mass index highlight a neuronal influence on body weight regulation

Common variants at only two loci, FTO and MC4R, have been reproducibly associated with body mass index (BMI) in humans. To identify additional loci, we conducted meta-analysis of 15 genome-wide association studies for BMI (n > 32,000) and followed up top signals in 14 additional cohorts (n > 59,000). We strongly confirm FTO and MC4R and identify six additional loci (P < 5 x 10(-8)): TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2 and NEGR1 (where a 45-kb deletion polymorphism is a candidate causal variant). Several of the likely causal genes are highly expressed or known to act in the central nervous system (CNS), emphasizing, as in rare monogenic forms of obesity, the role of the CNS in predisposition to obesity.

Data-driven treatment selection for seamless phase II/III trials incorporating early-outcome data

Seamless phase II/III clinical trials are conducted in two stages with treatment selection at the first stage. In the first stage, patients are randomized to a control or one of k > 1 experimental treatments. At the end of this stage, interim data are analysed, and a decision is made concerning which experimental treatment should continue to the second stage. If the primary endpoint is observable only after some period of follow-up, at the interim analysis data may be available on some early outcome on a larger number of patients than those for whom the primary endpoint is available. These early endpoint data can thus be used for treatment selection. For two previously proposed approaches, the power has been shown to be greater for one or other method depending on the true treatment effects and correlations. We propose a new approach that builds on the previously proposed approaches and uses data available at the interim analysis to estimate these parameters and then, on the basis of these estimates, chooses the treatment selection method with the highest probability of correctly selecting the most effective treatment. This method is shown to perform well compared with the two previously described methods for a wide range of true parameter values. In most cases, the performance of the new method is either similar to or, in some cases, better than either of the two previously proposed methods.

A comparison of methods for treatment selection in seamless phase II/III clinical trials incorporating information on short-term endpoints

In an adaptive seamless phase II/III clinical trial interim analysis, data are used for treatment selection, enabling resources to be focused on comparison of more effective treatment(s) with a control. In this paper, we compare two methods recently proposed to enable use of short-term endpoint data for decision-making at the interim analysis. The comparison focuses on the power and the probability of correctly identifying the most promising treatment. We show that the choice of method depends on how well short-term data predict the best treatment, which may be measured by the correlation between treatment effects on short- and long-term endpoints.

Flexible selection of a single treatment incorporating short-term endpoint information in a phase II/III clinical trial

Seamless phase II/III clinical trials in which an experimental treatment is selected at an interim analysis have been the focus of much recent research interest. Many of the methods proposed are based on the group sequential approach. This paper considers designs of this type in which the treatment selection can be based on short-term endpoint information for more patients than have primary endpoint data available. We show that in such a case, the familywise type I error rate may be inflated if previously proposed group sequential methods are used and the treatment selection rule is not specified in advance. A method is proposed to avoid this inflation by considering the treatment selection that maximises the conditional error given the data available at the interim analysis. A simulation study is reported that illustrates the type I error rate inflation and compares the power of the new approach with two other methods: a combination testing approach and a group sequential method that does not use the short-term endpoint data, both of which also strongly control the type I error rate. The new method is also illustrated through application to a study in Alzheimer's disease. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Global change pressures on soils from land use and management

Soils are subject to varying degrees of direct or indirect human disturbance, constituting a major global change driver. Factoring out natural from direct and indirect human influence is not always straightforward, but some human activities have clear impacts. These include land use change, land management, and land degradation (erosion, compaction, sealing and salinization). The intensity of land use also exerts a great impact on soils, and soils are also subject to indirect impacts arising from human activity, such as acid deposition (sulphur and nitrogen) and heavy metal pollution. In this critical review, we report the state-of-the-art understanding of these global change pressures on soils, identify knowledge gaps and research challenges, and highlight actions and policies to minimise adverse environmental impacts arising from these global change drivers. Soils are central to considerations of what constitutes sustainable intensification. Therefore, ensuring that vulnerable and high environmental value soils are considered when protecting important habitats and ecosystems, will help to reduce the pressure on land from global change drivers. To ensure that soils are protected as part of wider environmental efforts, a global soil resilience programme should be considered, to monitor, recover or sustain soil fertility and function, and to enhance the ecosystem services provided by soils. Soils cannot, and should not, be considered in isolation of the ecosystems that they underpin and vice versa. The role of soils in supporting ecosystems and natural capital needs greater recognition. The lasting legacy of the International Year of Soils in 2015 should be to put soils at the centre of policy supporting environmental protection and sustainable development.

Uma "ilha assombrada" na cidade : estudo etnográfico sobre cotidiano e memória coletiva a partir das narrativas de antigos moradores da Ilha Grande dos Marinheiros, Porto Alegre

Esta dissertação pretende apresentar uma etnografia realizada entre antigos moradores da Ilha Grande dos Marinheiros, em Porto Alegre. Enfocam-se suas lembranças na forma de narrativas orais em que contam sobre o cotidiano do lugar onde vivem e suas trajetórias sociais que conformam uma experiência diferenciada de habitar a cidade de Porto Alegre a partir do Bairro Arquipélago, com sua peculiar característica insular. Tomando o Arquipélago enquanto um “território-mito” da cidade, realiza-se a análise da “arte de dizer” desses narradores antigos e das constelações de imagens presentes ao repertório de narrativas míticas, contos fantásticos e lendários sobre desenterramentos de tesouros, aparições e assombrações, lobisomens e bruxaria que remetem, a partir da atual paisagem das ilhas, aos mitos de fundação da Cidade de Porto Alegre e ao trajeto antropológico de assimilação e acomodação da figura de um “Homem da Tradição” às margens da cidade.

Trabalho, meio ambiente e conflito : um estudo antropológico sobre a construção da identidade social dos pescadores do Parque Nacional da Lagoa do Peixe - RS

Esta pesquisa consiste em uma leitura da vida social de pescadores do Parque Nacional da Lagoa do Peixe, - RS, a partir da organização do trabalho na pesca, em um contexto de conflito com a política de Parques Nacionais, procurando apreender os significados deste conflito para esta comunidade de trabalho, assim como as representações que constituem sua identidade social.

Planeta Terra, cidade de Porto Alegre : uma etnografia entre internautas

Estudo de Antropologia Social elaborado a partir de uma pesquisa feita com um grupo que utiliza um chat de Internet como forma de sociabilidade. Reflete sobre a relação entre o homem e as Novas Tecnologias, assim como a cultura local e a Globalização. A sociabilidade virtual é vista em constante relação com a cidade de Porto Alegre. É investigada a relação da imagem digital com a interação social. A pesquisa também procura contribuir à reflexão sobre o papel da Antropologia diante de fenômenos sociais contemporâneos.

Ecos do subterrâneo : estudo antropológico do cotidiano e memória da comunidade de mineiros de carvão de Minas do Leão (RS)

Este trabalho consiste em um estudo etnográfico do cotidiano e da memória da comunidade de mineiros de carvão de Minas do Leão (RS). Por meio de suas representações, procuro desvendar a forma como se constitui sua identidade social, baseada no valor-trabalho, na sociabilidade, na afirmação da masculinidade, e no sentimento de heroísmo decorrente dos perigos enfrentados na mina subterrânea, desativada em 2002. Evidencio, nas narrativas, como o riso e as brincadeiras, estratégias usadas para afugentar o medo do acidente e da morte no subsolo, imprimiram sua marca na vida da comunidade.

"Fazer a Feira" : estudo etnográfico das "artes de fazer" de feirantes e fregueses da Feira Livre da Epatur no contexto da paisagem urbana de Porto Alegre

Esta dissertação trata de um estudo etnográfico sobre práticas cotidianas no contexto das feiras-livres em Porto Alegre (RS) a partir da análise das “artes de fazer”, formas de sociabilidade e performance de fregueses e feirantes da feira-Livre da Epatur. Este ato de “fazer a feira” encerra uma série de ações e gestos que evidenciam peculiaridades da “produção” do espaço urbano por certos habitantes da cidade. Em especial, estes gestos engendrados por feirantes e fregueses da feira-livre evocam formas específicas de habitar este território da cidade onde está situada a feira, o Bairro Cidade Baixa, configurando arranjos sociais particulares no que tange as trocais sociais de mercado que lá ocorrem. Enfatiza-se os atos de compra e venda de alimentos no mercado livre, as relações de sociabilidade que lá se estabelecem, a estética particular deste evento, sua ambiência –visual e sonora – como elementos que conformam este “espaço vivido” ao mesmo tempo em que tecem uma vivência particular da cidade de Porto Alegre. Neste estudo etnográfico analisa-se as “artes de nutrir” – gestos de manipulação da matéria – e “artes de dizer” – jocosidades, performances e jogos corporais para atrair clientes – respectivamente, como formas de estetizar o espaço da cidade a partir das práticas sociais de bairro.