1,273 research outputs found

    Sediment pollution impacts sensory ability and performance of settling coral-reef fish

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    © 2015, Springer-Verlag Berlin Heidelberg. Marine organisms are under threat globally from a suite of anthropogenic sources, but the current emphasis on global climate change has deflected the focus from local impacts. While the effect of increased sedimentation on the settlement of coral species is well studied, little is known about the impact on larval fish. Here, the effect of a laterite “red soil” sediment pollutant on settlement behaviour and post-settlement performance of reef fish was tested. In aquarium tests that isolated sensory cues, we found significant olfaction-based avoidance behaviour and disruption of visual cue use in settlement-stage larval fish at 50 mg L−1, a concentration regularly exceeded in situ during rain events. In situ light trap catches showed lower abundance and species richness in the presence of red soil, but were not significantly different due to high variance in the data. Prolonged exposure to red soil produced altered olfactory cue responses, whereby fish in red soil made a likely maladaptive choice for dead coral compared to controls where fish chose live coral. Other significant effects of prolonged exposure included decreased feeding rates and body condition. These effects on fish larvae reared over 5 days occurred in the presence of a minor drop in pH and may be due to the chemical influence of the sediment. Our results show that sediment pollution of coral reefs may have more complex effects on the ability of larval fish to successfully locate suitable habitat than previously thought, as well as impacting on their post-settlement performance and, ultimately, recruitment success

    Island rule and bone metabolism in fossil murines from Timor

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    Skeletal growth rates reconstructed from bone histology in extinct insular hippopotamids, elephants, bovids and sauropods have been used to infer dwarfism as a response to island conditions. Limited published records of osteocyte lacunae densities (Ot.Dn), a proxy for living osteocyte proliferation, have suggested a slower rate of bone metabolism in giant mammals. Here, we test whether insularity might have affected bone metabolism in a series of small to giant murine rodents from Timor. Ten adult femora were selected from a fossil assemblage dated to the Late Quaternary (~5000–18 000 years old). Femur morphometric data were used in computing phylogenetically informed body mass regressions, although the phylogenetic signal was very low (Pagel’s λ = 0.03). Estimates of body weight calculated from these femora ranged from 75 to 1188 g. Osteocyte lacunae densities from histological sections of the midshaft femur were evaluated against bone size and estimated body weight. Statistically significant (P < 0.05) and strongly negative relationships between Ot.Dn, femur size and estimated weight were found. Larger specimens were characterized by lower Ot.Dn, indicating that giant murines from Timor might have had a relatively slow pace of bone metabolic activity, consistent with predictions made by the island rule

    The holistic phase model of early adult crisis

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    The objective of the current study was to explore the structural, temporal and experiential manifestations of crisis episodes in early adulthood, using a holistic-systemic theoretical framework. Based on an analysis of 50 interviews with individuals about a crisis episode between the ages of 25 and 35, a holistic model was developed. The model comprises four phases: (1) Locked-in, (2) Separation/Time-out, (3) Exploration and (4) Rebuilding, which in turn have characteristic features at four levels—person-in-environment, identity, motivation and affect-cognition. A crisis starts out with a commitment at work or home that has been made but is no longer desired, and this is followed by an emotionally volatile period of change as that commitment is terminated. The positive trajectory of crisis involves movement through an exploratory period towards active rebuilding of a new commitment, but ‘fast-forward’ and ‘relapse’ loops can interrupt Phases 3 and 4 and make a positive resolution of the episode less likely. The model shows conceptual links with life stage theories of emerging adulthood and early adulthood, and it extends current understandings of the transitional developmental challenges that young adults encounter

    Academic Performance and Behavioral Patterns

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    Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students

    What do young adolescents think about taking part in longitudinal self-harm research?: findings from a school-based study

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    Background: Research about self-harm in adolescence is important given the high incidence in youth, and strong links to suicide and other poor outcomes. Clarifying the impact of involvement in school based self-harm studies on young adolescents is an ethical priority given heightened risk at this developmental stage. Methods: Here, 594 school-based students aged mainly 13-14 years completed a survey on self-harm at baseline and again 12-weeks later. Change in mood following completion of each survey, ratings and thoughts about participation, and responses to a mood-mitigation activity were analysed using a multi-method approach. Results: Baseline participation had no overall impact on mood. However, boys and girls reacted differently to the survey depending on self-harm status. Having a history of self-harm had a negative impact on mood for girls, but a positive impact on mood for boys. In addition, participants rated the survey in mainly positive/neutral terms, and cited benefits including personal insight and altruism. At follow-up, there was a negative impact on mood following participation, but no significant effect of gender or self-harm status. Ratings at follow-up were mainly positive/neutral. Those who had self-harmed reported more positive and fewer negative ratings than at baseline: the opposite pattern of response was found for those who had not self-harmed. Mood mitigation activities were endorsed. Conclusions: Self-harm research with youth is feasible in school settings. Most young people are happy to take part and cite important benefits. However, the impact of participation in research appears to vary according to gender, self-harm risk and method/time of assessment. The impact of repeated assessment requires clarification. Simple mood-elevation techniques may usefully help to mitigate distress

    Illness perceptions and explanatory models of viral hepatitis B & C among immigrants and refugees: a narrative systematic review.

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    © 2015 Owiti et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Hepatitis B and C (HBV, HCV) infections are associated with high morbidity and mortality. Many countries with traditionally low prevalence (such as UK) are now planning interventions (screening, vaccination, and treatment) of high-risk immigrants from countries with high prevalence. This review aimed to synthesise the evidence on immigrants' knowledge of HBV and HCV that might influence the uptake of clinical interventions. The review was also used to inform the design and successful delivery of a randomised controlled trial of targeted screening and treatment. METHODS: Five databases (PubMed, CINHAL, SOCIOFILE, PsycINFO & Web of Science) were systematically searched, supplemented by reference tracking, searches of selected journals, and of relevant websites. We aimed to identify qualitative and quantitative studies that investigated knowledge of HBV and HCV among immigrants from high endemic areas to low endemic areas. Evidence, extracted according to a conceptual framework of Kleinman's explanatory model, was subjected to narrative synthesis. We adapted the PEN-3 model to categorise and analyse themes, and recommend strategies for interventions to influence help-seeking behaviour. RESULTS: We identified 51 publications including quantitative (n = 39), qualitative (n = 11), and mixed methods (n = 1) designs. Most of the quantitative studies included small samples and had heterogeneous methods and outcomes. The studies mainly concentrated on hepatitis B and ethnic groups of South East Asian immigrants residing in USA, Canada, and Australia. Many immigrants lacked adequate knowledge of aetiology, symptoms, transmission risk factors, prevention strategies, and treatment, of hepatitis HBV and HCV. Ethnicity, gender, better education, higher income, and English proficiency influenced variations in levels and forms of knowledge. CONCLUSION: Immigrants are vulnerable to HBV and HCV, and risk life-threatening complications from these infections because of poor knowledge and help-seeking behaviour. Primary studies in this area are extremely diverse and of variable quality precluding meta-analysis. Further research is needed outside North America and Australia

    Maternal corticotropin-releasing hormone is associated with LEP DNA methylation at birth and in childhood: an epigenome-wide study in Project Viva

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    BackgroundCorticotropin-releasing hormone (CRH) plays a central role in regulating the secretion of cortisol which controls a wide range of biological processes. Fetuses overexposed to cortisol have increased risks of disease in later life. DNA methylation may be the underlying association between prenatal cortisol exposure and health effects. We investigated associations between maternal CRH levels and epigenome-wide DNA methylation of cord blood in offsprings and evaluated whether these associations persisted into mid-childhood.MethodsWe investigated mother-child pairs enrolled in the prospective Project Viva pre-birth cohort. We measured DNA methylation in 257 umbilical cord blood samples using the HumanMethylation450 Bead Chip. We tested associations of maternal CRH concentration with cord blood cells DNA methylation, adjusting the model for maternal age at enrollment, education, maternal race/ethnicity, maternal smoking status, pre-pregnancy body mass index, parity, gestational age at delivery, child sex, and cell-type composition in cord blood. We further examined the persistence of associations between maternal CRH levels and DNA methylation in children's blood cells collected at mid-childhood (n = 239, age: 6.7-10.3 years) additionally adjusting for the children's age at blood drawn.ResultsMaternal CRH levels are associated with DNA methylation variability in cord blood cells at 96 individual CpG sites (False Discovery Rate &lt;0.05). Among the 96 CpG sites, we identified 3 CpGs located near the LEP gene. Regional analyses confirmed the association between maternal CRH and DNA methylation near LEP. Moreover, higher maternal CRH levels were associated with higher blood-cell DNA methylation of the promoter region of LEP in mid-childhood (P &lt; 0.05, β = 0.64, SE = 0.30).ConclusionIn our cohort, maternal CRH was associated with DNA methylation levels in newborns at multiple loci, notably in the LEP gene promoter. The association between maternal CRH and LEP DNA methylation levels persisted into mid-childhood

    Future-oriented constructs and their role in suicidal ideation and enactment

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    Despite the heavy focus upon risk factors for suicide, the presence or absence of protective factors are also instrumental in individuals’ vulnerability for developing suicidal ideation and behaviours. Future oriented constructs, including future thinking, future orientation, hope and optimism have been associated with suicidal ideation and behaviour; individuals who are less able to generate positive thoughts about the future, and those are less hopeful and optimistic are more likely to think about or engage in suicidal behaviours. The content and expectations of future thoughts as achievable also play a key role in their protective capacity. Within this chapter we discuss the relationships between future orientated constructs and suicidal ideation and behaviour, as well as potential mediators of these relationships, within the context of the new generation of ideation-to-action frameworks of suicidal behaviour. We also highlight challenges and opportunities for future research and intervention development for suicidal thoughts and behaviours using future oriented constructs

    Ambient-aware continuous care through semantic context dissemination

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    Background: The ultimate ambient-intelligent care room contains numerous sensors and devices to monitor the patient, sense and adjust the environment and support the staff. This sensor-based approach results in a large amount of data, which can be processed by current and future applications, e. g., task management and alerting systems. Today, nurses are responsible for coordinating all these applications and supplied information, which reduces the added value and slows down the adoption rate. The aim of the presented research is the design of a pervasive and scalable framework that is able to optimize continuous care processes by intelligently reasoning on the large amount of heterogeneous care data. Methods: The developed Ontology-based Care Platform (OCarePlatform) consists of modular components that perform a specific reasoning task. Consequently, they can easily be replicated and distributed. Complex reasoning is achieved by combining the results of different components. To ensure that the components only receive information, which is of interest to them at that time, they are able to dynamically generate and register filter rules with a Semantic Communication Bus (SCB). This SCB semantically filters all the heterogeneous care data according to the registered rules by using a continuous care ontology. The SCB can be distributed and a cache can be employed to ensure scalability. Results: A prototype implementation is presented consisting of a new-generation nurse call system supported by a localization and a home automation component. The amount of data that is filtered and the performance of the SCB are evaluated by testing the prototype in a living lab. The delay introduced by processing the filter rules is negligible when 10 or fewer rules are registered. Conclusions: The OCarePlatform allows disseminating relevant care data for the different applications and additionally supports composing complex applications from a set of smaller independent components. This way, the platform significantly reduces the amount of information that needs to be processed by the nurses. The delay resulting from processing the filter rules is linear in the amount of rules. Distributed deployment of the SCB and using a cache allows further improvement of these performance results
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