Multiple stressors in a top predator seabird: potential ecological consequences of environmental contaminants, population health and breeding conditions

Environmental contaminants may have impacts on reproduction and survival in wildlife populations suffering from multiple stressors. This study examined whether adverse effects of persistent organic pollutants (POPs) increased with poor population health and breeding conditions in three colonies (60–74°N) of great skua (Stercorarius skua) in the north-eastern Atlantic (Shetland, Iceland and Bjørnøya [Bear Island]). POPs (organochlorines [OCs] and polybrominated diphenyl ethers [BDEs]) were measured in plasma of incubating birds (n = 222), concentrations differing nearly tenfold among colonies: Bjørnøya (2009) > Bjørnøya (2010) > Iceland (2009) > Shetland (2009). Reproductive success (hatching success and chick survival) showed that breeding conditions were favourable in Shetland and at Bjørnøya (2010), but were very poor in Iceland and at Bjørnøya (2009). Biomarkers indicated that health was poor in the Shetland population compared to the other populations. Females whose chicks hatched late had high POP concentrations in all colonies except at Bjørnøya (2010), and females losing their eggs at Bjørnøya (2009) tended to have higher concentrations than those hatching. Moreover, there was a negative relationship between female POP concentrations and chick body condition at hatching in Iceland and at Bjørnøya (2010). Supplementary feeding experiments were conducted, and in Iceland where feeding conditions were poor, significant negative relationships were found between female POP concentrations and daily growth-rate in first-hatched chicks of control nests, but not in food supplemented nests. This suggests that negative impacts of POPs were mitigated by improved feeding conditions. For second-chicks, there was a strong negative relationship between the female POP concentrations and growth-rate, but no effects of supplementary feeding. Lowered adult return-rate between breeding seasons with increasing POP loads were found both at Bjørnøya (2009) and in Shetland, especially related to BDEs. This indicates stronger fitness consequences of POPs following seasons with very poor breeding conditions and/or high reproductive effort. This study suggests that the impacts of POPs may differ depending on population health and breeding conditions, and that even low concentrations of POPs could have ecological consequences during adverse circumstances. This is important with regard to risk assessment of biomagnifying contaminants in marine ecosystems

Parametrized spaces model locally constant homotopy sheaves

We prove that the homotopy theory of parametrized spaces embeds fully and faithfully in the homotopy theory of simplicial presheaves, and that its essential image consists of the locally homotopically constant objects. This gives a homotopy-theoretic version of the classical identification of covering spaces with locally constant sheaves. We also prove a new version of the classical result that spaces parametrized over X are equivalent to spaces with an action of the loop space of X. This gives a homotopy-theoretic version of the correspondence between covering spaces over X and sets with an action of the fundamental group of X. We then use these two equivalences to study base change functors for parametrized spaces.Comment: 26 pages; exposition improve

Nursing staff’s knowledge and attitudes towards Dementia in an Indian nursing home: A qualitative interview study

Background: Despite the increased prevalence of dementia in India, there is reported to be little awareness of the disease. This could lead to a late diagnosis, a reduced number of choices regarding future care, and misinterpretation of the symptoms or neglect. Taking into consideration that most nurses caring for older people in the future will work with people with dementia, there is concern that they may not be able to meet the needs of this group of patients unless they have the necessary knowledge and a positive attitude. Aim: To explore the knowledge about and attitude towards dementia among nursing staff working in residential care facilities for older people in India. Method: An explorative and descriptive qualitative design was used. Two semistructured focus group interviews were conducted with nursing staff working in 6 nursing homes in India. Qualitative content analysis was used. Ethical approval was granted by the Norwegian Social Science Data Services. Findings: The participants highlighted the following 3 dimensions in relation to their knowledge of and attitudes toward dementia in residential care facilities in India: (1) people with dementia – a walking mystery; (2) we need to go along with them, but it is challenging; and (3) if we know, we can care for them in a better way. Conclusion: The findings revealed a wide range of differences in attitude towards and inadequate knowledge of dementia among nursing staff. However, their overall attitudes toward people with dementia was positive.publishedVersio

Sociodemographic characteristics and food habits of organic consumers--a study from the Danish National Birth Cohort.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageTo develop a basis for building models that can examine the impact of organic food (OF) choices on maternal and offspring health, including identification of factors associated with OF consumption and underlying dietary patterns.Dietary intake was collected for the preceding month from an FFQ in mid-pregnancy and information on sociodemographic characteristics was collected from telephone interviews during pregnancy. From a question about OF consumption in the FFQ, including six food categories, an OF preference index was calculated. Latent variables that captured the variability in OF choices in relation to dietary intake were defined.The Danish National Birth Cohort (DNBC), 1996-2002.Pregnant women from DNBC (n 60,773).We found that frequent OF use was highly associated with age, occupational status, urbanization, smoking and vegetarianism. By principal components analysis we identified two eating patterns, a ‘Western dietary pattern’ and a ‘Prudent dietary pattern’, that explained 14.2% of the variability in data. Frequent OF users consumed a more ‘prudent’ diet compared with non-users and had significantly higher intakes of vegetables (167%), fibre (113%) and n-3 fatty acids (111%) and less saturated fat (28%).Frequent OF users seemed to have a healthier lifestyle than non-users. These findings highlight a major challenge in observational studies examining the impact of OF consumption on health due to potentially irremediable confounding factors.Danish Fund for Organic Agriculture European Union Integrated Research Project EARNEST/FOOD-CT-2005-007036 Danish Council for Strategic Research 09-067124 March of Dimes Birth Defects Foundation Danish Heart Association Danish Medical Research Council Sygekassernes Helsefond Danish National Research Foundation Danish Pharmaceutical Association Ministry of Health National Board of Health Statens Serum Institu

Sea trout Salmo trutta in the subarctic: home-bound but large variation in migratory behaviour between and within populations

publishedVersio

α,α-disubstituted β-amino amides eliminate Staphylococcus aureus biofilms by membrane disruption and biomass removal

Bacterial biofilms account for up to 80% of all infections and complicate successful therapies due to their intrinsic tolerance to antibiotics. Biofilms also cause serious problems in the industrial sectors, for instance due to the deterioration of metals or microbial contamination of products. Efforts are put in finding novel strategies in both avoiding and fighting biofilms. Biofilm control is achieved by killing and/or removing biofilm or preventing transition to the biofilm lifestyle. Previous research reported on the anti-biofilm potency of α,α-disubstituted β-amino amides A1, A2 and A3, which are small antimicrobial peptidomimetics with a molecular weight below 500 Dalton. In the current study it was investigated if these derivatives cause a fast disintegration of biofilm bacteria and removal of Staphylococcus aureus biofilms. One hour incubation of biofilms with all three derivatives resulted in reduced metabolic activity and membrane permeabilization in S. aureus (ATCC 25923) biofilms. Bactericidal properties of these derivatives were attributed to a direct effect on membranes of biofilm bacteria. The green fluorescence protein expressing Staphylococcus aureus strain AH2547 was cultivated in a CDC biofilm reactor and utilized for disinfectant efficacy testing of A3, following the single-tube method (American Society for Testing and Materials designation number E2871). A3 at a concentration of 90 μM acted as fast as 100 μM chlorhexidine and was equally effective. Confocal laser scanning microscopy studies showed that chlorhexidine treatment lead to fluorescence fading indicating membrane permeabilization but did not cause biomass removal. In contrast, A3 treatment caused a simultaneous biofilm fluorescence loss and biomass removal. These dual anti-biofilm properties make α,α-disubstituted β-amino amides promising scaffolds in finding new control strategies against recalcitrant biofilms

Political Party Mortality in Established Party Systems:A Hierarchical Competing Risks Approach

Existing scholarship offers few answers to fundamental questions about the mortality of political parties in established party systems. Linking party research to the organization literature, we conceptualize two types of party death, dissolution and merger, reflecting distinct theoretical rationales. They underpin a new framework on party organizational mortality theorizing three sets of factors: those shaping mortality generally and those shaping dissolution or merger death exclusively. We test this framework on a new data set covering the complete life cycles of 184 parties that entered 21 consolidated party systems over the last five decades, resorting to multilevel competing risks models to estimate the impact of party and country characteristics on the hazards of both types of death. Our findings not only show that dissolution and merger death are driven by distinct factors, but also that they represent separate logics not intrinsically related at either the party or systemic level

Two sword lengths apart: Credible commitment problems and physical violence in democratic national legislatures

Ideally, national legislatures in democracies should be venues for peacefully resolving conflicts between opposing groups. However, they can become places of physical violence. Such violence can be an indication that countries’ legislative institutions are functioning far from the democratic ideal of being venues for peaceful conflict reconciliation. In some cases, such as Ukraine prior to the 2014 outbreak of armed conflict in the country’s east and south, violence can indicate and possibly fuel deeper political divisions. In this first global study of legislative violence, I show that brawls are more likely when legislators find it difficult to credibly commit to follow peaceful bargains. Credible commitment problems are more acute in countries with new democracies and disproportionate electoral outcomes – that is, when electoral votes for parties do not closely correspond to the legislative seats they are given. I find robust support for this argument by first examining a case study of legislative violence in the antebellum United States Senate. Pro- and anti-slavery senators became increasingly unable to maintain credible commitments in the lead-up to the 1856 caning of Senator Charles Sumner as the allocation of seats in the legislative body became more disproportional. Second, I find further support for my argument in a new global dataset of contemporary instances of violence in national legislatures. In addition, I find strong evidence that violence is more likely in legislatures with small minority governments. Despite reasonable expectations, civil wars are not associated with more legislative violence