217 research outputs found

    The fitness of dispersing spotted hyaena sons is influenced by maternal social status

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    Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring's and their own fitness. In many mammals, high-ranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fitness benefits during adulthood from such privileges (a 'silver spoon' effect) has rarely been examined. In this paper, we show that in the complex, female-dominated society of spotted hyaenas, high-born sons grew at higher rates, were more likely to disperse to clans offering the best fitness prospects, started reproducing earlier and had a higher reproductive value than did lower-born sons. This illustrates the evolutionary importance of maternal effects even in societies in which male size or fighting ability does not influence fitness. By demonstrating for the first time in a non-human mammal that maternal status influences immigration patterns, the study also advances our understanding of two key ecological and evolutionary processes, dispersal and habitat selection

    Supertwistor space for 6D maximal super Yang-Mills

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    6D maximal super Yang-Mills on-shell amplitudes are formulated in superspace using 6 dimensional twistors. The 3,4,5-point tree amplitudes are obtained by supersymmetrizing their bosonic counterparts and confirmed through the BCFW construction. In contrast to 4D this superspace is non-chiral, reflecting the fact that one cannot differentiate MHV from MHVˉ\bar{{\rm MHV}} in 6D. Combined with unitarity methods, this superspace should be useful for the study of multi-loop D dimensional maximal super Yang-Mills and gravity amplitudes. Furthermore, the non-chiral nature gives a natural framework for an off-shell construction. We show this by matching our result with off-shell D=4 N=4 super Yang-Mills amplitudes, expressed in projective superspace.Comment: 6 figures 28 pages. with better sign

    The importance of post-translocation monitoring of habitat use and population growth: insights from a Seychelles Warbler (Acrocephalus sechellensis) translocation

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    Translocations are a valuable tool within conservation, and when performed successfully can rescue species from extinction. However, to label a translocation a success, extensive post-translocation monitoring is required, ensuring the population is growing at the expected rate. In 2011, a habitat assessment identified Frégate Island as a suitable island to host a Seychelles Warbler (Acrocephalus sechellensis) population. Later that year, 59 birds were translocated from Cousin Island to Frégate Island. Here, we determine Seychelles Warbler habitat use and population growth on Frégate Island, assessing the status of the translocation and identifying any interventions that may be required. We found that territory quality, an important predictor of fledgling production on Cousin Island, was a poor predictor of bird presence on Frégate Island. Instead, tree diversity, middle-storey vegetation density, and broad-leafed vegetation density all predicted bird presence positively. A habitat suitability map based on these results suggests most of Frégate Island contains either a suitable or a moderately suitable habitat, with patches of unsuitable overgrown coconut plantation. To achieve the maximum potential Seychelles Warbler population size on Frégate Island, we recommend habitat regeneration, such that the highly diverse subset of broad-leafed trees and a dense middle storey should be protected and replace the unsuitable coconut. Frégate Island’s Seychelles Warbler population has grown to 141 birds since the release, the slowest growth rate of all Seychelles Warbler translocations; the cause of this is unclear. This study highlights the value of post-translocation monitoring, identifying habitat use and areas requiring restoration, and ultimately ensuring that the population is growing

    Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

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    Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the FST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species

    Effects of work ability and health promoting interventions for women with musculoskeletal symptoms: A 9-month prospective study

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    <p>Abstract</p> <p>Background</p> <p>Women working in the public human service sector in 'overstrained' situations run the risk of musculoskeletal symptoms and long-term sick leave. In order to maintain the level of health and work ability and strengthen the potential resources for health, it is important that employees gain greater control over decisions and actions affecting their health – a process associated with the concept of self-efficacy. The aim of this study was to describe the effects of a self-efficacy intervention and an ergonomic education intervention for women with musculoskeletal symptoms, employed in the public sector.</p> <p>Methods</p> <p>The design of the study was a 9-month prospective study describing the effects of two interventions, a comprehensive self-efficacy intervention (<it>n </it>= 21) and an ergonomic education intervention (<it>n </it>= 21). Data were obtained by a self-report questionnaire on health- and work ability-related factors at baseline, and at ten weeks and nine months follow-up. Within-group differences over time were analysed.</p> <p>Results</p> <p>Over the time period studied there were small magnitudes of improvements within each group. Within the self-efficacy intervention group positive effects in perceived work ability were shown. The ergonomic education group showed increased positive beliefs about future work ability and a more frequent use of pain coping strategies.</p> <p>Conclusion</p> <p>Both interventions showed positive effects on women with musculoskeletal symptoms, but in different ways. Future research in this area should tailor interventions to participants' motivation and readiness to change.</p

    Additional Haplogroups of Toxoplasma gondii out of Africa: Population Structure and Mouse-Virulence of Strains from Gabon

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    Prevalence of human toxoplasmosis in tropical African countries usually exceeds 50%. Its role as a major opportunistic infection of AIDS patients is regularly described. Due to the lack of investigation, congenital infection is certainly underestimated in Africa. Incidence of Toxoplasma ocular disease is higher in Africa and South America than in Europe. Severe cases in immunocompetent patients were described after infection acquired in Amazonia, but nothing is known about such cases in Africa. Several studies argued for a role of genotypes in the clinical expression of human toxoplasmosis, and for a geographical structuration of Toxoplasma across continents. Genetic data concerning isolates from Africa are scarce. Here, apart from the worldwide Type III, we described two main haplogroups, Africa 1 and 3. We detected genetic exchanges between urban centers favored by trade exchange and transportation. It shows how important human influence is, even in shaping the genetic structure of a zoonotic disease agent. Finding of identical haplogroups in South America suggested that these African and American strains share a common ancestor. As a higher pathogenicity in human of South American genotypes has been described, this similarity of genotypes should encourage further clinical studies with genotype analysis in Africa

    Social Participation and Disaster Risk Reduction Behaviors in Tsunami Prone Areas

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    This paper examines the relationships between social participation and disaster risk reduction actions. A survey of 557 households in tsunami prone areas in Phang Nga, Thailand was conducted following the 2012 Indian Ocean earthquakes. We use a multivariate probit model to jointly estimate the likelihood of undertaking three responses to earthquake and tsunami hazards (namely, (1) following disaster-related news closely, (2) preparing emergency kits and/or having a family emergency plan, and (3) having an intention to migrate) and community participation.We find that those who experienced losses from the 2004 tsunami are more likely to participate in community activities and respond to earthquake hazards. Compared to men, women are more likely to prepare emergency kits and/or have an emergency plan and have a greater intention to migrate. Living in a community with a higher proportion of women with tertiary education increases the probability of engaging in community activities and carrying out disaster risk reduction measures. Individuals who participate in village-based activities are 5.2% more likely to undertake all three risk reduction actions compared to those not engaging in community activities. This implies that encouraging participation in community activities can have positive externalities in disaster mitigation

    Early life factors and being overweight at 4 years of age among children in Malmö, Sweden

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    <p>Abstract</p> <p>Background</p> <p>Rising rates of obesity and overweight is an increasing public health problem all over the world. Recent research has shown the importance of early life factors in the development of child overweight. However, to the best of our knowledge there are no studies investigating the potential synergistic effect of early life factors and presence of parental overweight on the development of child overweight.</p> <p>Methods</p> <p>The study was population-based and cross-sectional. The study population consisted of children who visited the Child Health Care (CHC) centers in Malmö for their 4-year health check during 2003-2008 and whose parents answered a self-administered questionnaire (n = 9009 children).</p> <p>Results</p> <p>The results showed that having overweight/obese parents was strongly associated with the child being overweight or obese. Furthermore, there was an association between unfavorable early life factors (i.e., mother smoking during pregnancy, presence of secondhand tobacco smoke early in life, high birth weight) and the development of child overweight/obesity at four years of age, while breastfeeding seemed to have a protective role. For example, maternal smoking during pregnancy was associated with an odds ratio (OR) of 1.47 (95% CI: 1.22, 1.76) for overweight and 2.31 (95% CI: 1.68, 3.17) for obesity. The results further showed synergistic effects between parental overweight and exposure to unfavourable early life factors in the development of child overweight.</p> <p>Conclusions</p> <p>The present study shows the importance of early life factors in the development of child overweight and obesity, and thus puts focus on the importance of early targeted interventions.</p

    Exercise training with dietary counselling increases mitochondrial chaperone expression in middle-aged subjects with impaired glucose tolerance

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    <p>Abstract</p> <p>Background</p> <p>Insulin resistance and diabetes are associated with increased oxidative stress and impairment of cellular defence systems. Our purpose was to investigate the interaction between glucose metabolism, antioxidative capacity and heat shock protein (HSP) defence in different skeletal muscle phenotypes among middle-aged obese subjects during a long-term exercise and dietary intervention. As a sub-study of the Finnish Diabetes Prevention Study (DPS), 22 persons with impaired glucose tolerance (IGT) taking part in the intervention volunteered to give samples from the <it>vastus lateralis </it>muscle. Subjects were divided into two sub-groups (IGTslow and IGTfast) on the basis of their baseline myosin heavy chain profile. Glucose metabolism, oxidative stress and HSP expressions were measured before and after the 2-year intervention.</p> <p>Results</p> <p>Exercise training, combined with dietary counselling, increased the expression of mitochondrial chaperones HSP60 and glucose-regulated protein 75 (GRP75) in the <it>vastus lateralis </it>muscle in the IGTslow group and that of HSP60 in the IGTfast group. In cytoplasmic chaperones HSP72 or HSP90 no changes took place. In the IGTslow group, a significant positive correlation between the increased muscle content of HSP60 and the oxygen radical absorbing capacity values and, in the IGTfast group, between the improved VO<sub>2max </sub>value and the increased protein expression of GRP75 were found. Serum uric acid concentrations decreased in both sub-groups and serum protein carbonyl concentrations decreased in the IGTfast group.</p> <p>Conclusion</p> <p>The 2-year intervention up-regulated mitochondrial HSP expressions in middle-aged subjects with impaired glucose tolerance. These improvements, however, were not correlated directly with enhanced glucose tolerance.</p

    Macrocheles species (Acari: Macrochelidae) associated with human corpses in Europe

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    The biology of macrochelid mites might offer new venues for the interpretation of the environmental conditions surrounding human death and decomposition. Three human corpses, one from Sweden and two from Spain, have been analysed for the occurrence of Macrochelidae species. Macrocheles muscaedomesticae females were associated with a corpse that was found in a popular beach area of southeast Spain. Their arrival coincides with the occurrence of one of their major carrier species, the filth fly Fannia scalaris, the activity of which peaks during mid-summer. M. glaber specimens were collected from a corpse in a shallow grave in a forest in Sweden at the end of summer, concurrent with the arrival of beetles attracted by odours from the corpse. M. perglaber adults were sampled from a corpse found indoors in the rural surroundings of Granada city, Spain. The phoretic behaviour of this species is similar to that of M. glaber, but being more specific to Scarabaeidae and Geotrupidae dung beetles, most of which favour human faeces. M. muscaedomesticae is known from urban and rural areas and poultry farms; M. glaber from outdoors, particularly the countryside; while M. perglaber from outdoor, rural, and remote, potentially mountainous locations. M. muscaedomesticae and M. perglaber are reported for the first time from the Iberian Peninsula. This is the first record of M. perglaber from human remains
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