78 research outputs found

    Land Cover and Rainfall Interact to Shape Waterbird Community Composition

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    Human land cover can degrade estuaries directly through habitat loss and fragmentation or indirectly through nutrient inputs that reduce water quality. Strong precipitation events are occurring more frequently, causing greater hydrological connectivity between watersheds and estuaries. Nutrient enrichment and dissolved oxygen depletion that occur following these events are known to limit populations of benthic macroinvertebrates and commercially harvested species, but the consequences for top consumers such as birds remain largely unknown. We used non-metric multidimensional scaling (MDS) and structural equation modeling (SEM) to understand how land cover and annual variation in rainfall interact to shape waterbird community composition in Chesapeake Bay, USA. The MDS ordination indicated that urban subestuaries shifted from a mixed generalist-specialist community in 2002, a year of severe drought, to generalist-dominated community in 2003, of year of high rainfall. The SEM revealed that this change was concurrent with a sixfold increase in nitrate-N concentration in subestuaries. In the drought year of 2002, waterbird community composition depended only on the direct effect of urban development in watersheds. In the wet year of 2003, community composition depended both on this direct effect and on indirect effects associated with high nitrate-N inputs to northern parts of the Bay, particularly in urban subestuaries. Our findings suggest that increased runoff during periods of high rainfall can depress water quality enough to alter the composition of estuarine waterbird communities, and that this effect is compounded in subestuaries dominated by urban development. Estuarine restoration programs often chart progress by monitoring stressors and indicators, but rarely assess multivariate relationships among them. Estuarine management planning could be improved by tracking the structure of relationships among land cover, water quality, and waterbirds. Unraveling these complex relationships may help managers identify and mitigate ecological thresholds that occur with increasing human land cover

    The relationship between acculturation preferences and prejudice:Longitudinal evidence from majority and minority groups in three European countries

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    A longitudinal field survey tested the reciprocal effects of acculturation preferences and prejudice among ethnic minorities and majorities. Data were collected at two points in time from 512 members of ethnic minorities and 1143 majority members in Germany, Belgium and England. Path analyses yielded not only the lagged effects of prejudice on acculturation preferences but also the reverse for both majority and minority members. The mutual longitudinal effects between prejudice and desire for culture maintenance were negative, and the mutual effects between prejudice and desire for culture adoption were positive for majority members. The reverse was the case for minority participants. Moreover, the two acculturation dimensions interacted in their effect on prejudice for majority participants but not for minority participants. The effect of desire for culture adoption on prejudice was moderated by perceived intergroup similarity. Theoretical and practical implications of the findings are discussed. Copyright © 2014 John Wiley & Sons, Ltd

    TRAIL inhibits angiogenesis stimulated by VEGF expression in human glioblastoma cells

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    Tumour growth is tightly related to new blood vessel formation, tissue remodelling and invasiveness capacity. A number of tissular factors fuel the growth of glioblastoma multiforme, the most aggressive brain neoplasm. In fact, gene array analyses demonstrated that the proapoptotic cytokine tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) inhibited mRNA expression of VEGF, along with those of matrix metalloproteinase-2 (MMP-2), its inhibitor tissue inhibitor of matrix metalloproteinases-2 (TIMP-2), as well as the tumour invasiveness-related gene secreted protein acid rich in cysteine (SPARC) in different human glioblastoma cell lines. Particularly, VEGF mRNA and protein expression and release from glioblastoma cells were also inhibited by TRAIL. The latter also exerted antimitogenic effects on human umbilical vein endothelial cells (HUVECs). With the same cells, TRAIL inhibited new vessel formation in the in vitro matrigel model, as well as it exerted powerful inhibition of blood vessel formation induced by an angiogenic cocktail administered in subcutaneous pellets in vivo in the C57 mouse. Moreover, the expression of MMP-2, its inhibitor TIMP-2 and the tumour invasiveness-related protein SPARC were effectively inhibited by TRAIL in glioblastoma cell lines. In conclusion, our data indicate that TRAIL inhibits the orchestra of factors contributing to glioblastoma biological aggressiveness. Thus, the TRAIL system could be regarded as a molecular target to exploit for innovative therapy of this type of tumour

    DNA methylation levels in candidate genes associated with chronological age in mammals are not conserved in a long-lived seabird

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    © 2017 De Paoli-Iseppi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most seabirds do not have any outward identifiers of their chronological age, so estimation of seabird population age structure generally requires expensive, long-term banding studies. We investigated the potential to use a molecular age biomarker to estimate age in short-tailed shearwaters (Ardenna tenuirostris). We quantified DNA methylation in several A. tenuirostris genes that have shown age-related methylation changes in mammals. In birds ranging from chicks to 21 years of age, bisulphite treated blood and feather DNA was sequenced and methylation levels analysed in 67 CpG sites in 13 target gene regions. From blood samples, five of the top relationships with age were identified in KCNC3 loci (CpG66: R2 = 0.325, p = 0.019). In feather samples ELOVL2 (CpG42: R2 = 0.285, p = 0.00048) and EDARADD (CpG46: R2 = 0.168, p = 0.0067) were also weakly correlated with age. However, the majority of markers had no clear association with age (of 131 comparisons only 12 had a p-value < 0.05) and statistical analysis using a penalised lasso approach did not produce an accurate ageing model. Our data indicate that some age-related signatures identified in orthologous mammalian genes are not conserved in the long-lived short tailed shearwater. Alternative molecular approaches will be required to identify a reliable biomarker of chronological age in these seabirds

    Alcohol devaluation has dissociable effects on distinct components of alcohol behaviour

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    Rationale Substance-related behaviour is often viewed as an appetitive behaviour, motivated by the reinforcing effects of the drug. However, there are various indices of substance motivation (e.g. attentional bias, behavioural economic demand, craving) and it is unclear how these are related or whether they play an important role in all types of substance-related behaviour. Objectives (1) To determine the effect of alcohol devaluation on several indices of alcohol motivation and goal-directed and cue-elicited alcohol behaviour. (2) To investigate which components of motivation mediate any effect of devaluation on behaviour. Methods Sixty-two social drinkers gave baseline measures of alcohol craving, behavioural economic demand and choice for alcohol vs. soft drink. Participants tasted alcohol which was either unadulterated (control) or adulterated with a bitter solution (devaluation) before craving and demand were measured again. Alcohol choice was assessed in several phases: extinction (evaluating goal-directed behaviour), in the presence of drink cues (Pavlovian-to-instrumental transfer (PIT, cue-elicited behaviour)), and reacquisition. Attentional bias (AB) was measured by tracking eye movements towards the drink cues during novel PIT trials where both cues were presented. Finally, consumption was evaluated in a taste test. Results Alcohol devaluation reduced alcohol-related demand, AB, alcohol choice in all phases, and consumption. Alcohol cues presented during PIT increased alcohol choice above baseline irrespective of devaluation. AB and demand for alcohol fully mediated the effect of devaluation on alcohol choice during extinction, AB fully mediated the effect on cue-elicited (specific PIT) alcohol choice and alcohol consumption. Conclusions Alcohol behaviour in social drinkers is largely sensitive to devaluation, i.e. governed by current motivational value of the drug (suggesting goal-directed behaviour). However, a dissociable form of stimulus control can also drive alcohol-seeking independently of drug value (specific PIT). Mediation analyses suggests that AB may play a paradoxical role in both forms of alcohol seeking and consumption

    The role of teacher behavior management in the development of disruptive behaviors: an intervention study with the good behavior game

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    Abstract The role of teacher behavior management for children’s disruptive behavior development (hyperactive and oppositional behavior) was investigated using a universal classroom preventive intervention study. Five-hundred seventy children were followed from second to third grade of elementary school. Observations of teacher behavior management and children’s on-task and off-task classroom behavior and peer reports of hyperactive and oppositional behavior were available. Results showed that the reduced use of negative remarks of intervention teachers predicted children’s increase in on-task behavior and decrease in talking-out behavior. These improved children’s classroom behaviors in turn mediated the impact of the intervention on the development of hyperactive and oppositional behavior over the studied period. These results were similar for girls and boys. The results underscore the role of teachers’ classroom management strategies in improving children’s classroom behavior, which, in turn is an important component in the reduction of disruptive behavior development

    Perspectives on the use of transcriptomics to advance biofuels

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    As a field within the energy research sector, bioenergy is continuously expanding. Although much has been achieved and the yields of both ethanol and butanol have been improved, many avenues of research to further increase these yields still remain. This review covers current research related with transcriptomics and the application of this high-throughput analytical tool to engineer both microbes and plants with the penultimate goal being better biofuel production and yields. The initial focus is given to the responses of fermentative microbes during the fermentative production of acids, such as butyric acid, and solvents, including ethanol and butanol. As plants offer the greatest natural renewable source of fermentable sugars within the form of lignocellulose, the second focus area is the transcriptional responses of microbes when exposed to plant hydrolysates and lignin-related compounds. This is of particular importance as the acid/base hydrolysis methods commonly employed to make the plant-based cellulose available for enzymatic hydrolysis to sugars also generates significant amounts of lignin-derivatives that are inhibitory to fermentative bacteria and microbes. The article then transitions to transcriptional analyses of lignin-degrading organisms, such as Phanerochaete chrysosporium, as an alternative to acid/base hydrolysis. The final portion of this article will discuss recent transcriptome analyses of plants and, in particular, the genes involved in lignin production. The rationale behind these studies is to eventually reduce the lignin content present within these plants and, consequently, the amount of inhibitors generated during the acid/base hydrolysis of the lignocelluloses. All four of these topics represent key areas where transcriptomic research is currently being conducted to identify microbial genes and their responses to products and inhibitors as well as those related with lignin degradation/formation.clos

    Kinematics and dynamics of OH/IR stars

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