718 research outputs found

    Helpers and egg investment in the cooperatively breeding acorn woodpecker: testing the concealed helper effects hypothesis

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    In cooperatively breeding acorn woodpeckers (Melanerpes formicivorus), helper males have a large positive effect on fledging success in good acorn crop years but only a small positive effect in poor acorn crop years, while helper females exhibit the opposite pattern. Based on these findings, we tested the “concealed helper effects” hypothesis, which proposes that laying females reduce investment in eggs (with respect to their size, number, or quality) in a way that confounds helper effects and results in an absence of a relationship between helpers and breeding success. Results generally failed to support the hypothesis. Mean egg size was positively related to temperatures during the 10 days prior to egg-laying and negatively related to the food supply as indexed by the prior fall’s acorn crop, but there were no significant differences vis-à-vis helpers except for interactions with the acorn crop that only partly corresponded to those predicted. With respect to clutch size, females laid larger clutches when assisted by female helpers, opposite the pattern predicted. Although our results suggest that egg size is adjusted to particular ecological circumstances, we conclude that neither egg nor clutch size is adjusted in a way that confounds the apparent effects of helpers, as proposed by the concealed helper effects hypothesis

    Applying human factors methods to explore ‘Work as Imagined’ and ‘Work as Done’ in the Emergency Department’s response to chemical, biological, radiological, and nuclear events

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    The Emergency Department (ED) is a complex, hectic, and high-pressured environment. Chemical, Biological, Radiological, and Nuclear (CBRN) events are multi-faceted emergencies and present numerous challenges to ED staff (first receivers) with large scale trauma, consequently requiring a combination of complex responses. Human Factors and Ergonomics (HF/E) methods such as Hierarchical Task Analysis (HTA) have been used in healthcare research. However, HF/E methods and theory have not been combined to understand how the ED responds to CBRN events. This study aimed to compare Work as Imagined (WAI) and Work as Done (WAD) in the ED CBRN response in a UK based hospital. WAI was established by carrying out document analyses on a CBRN plan and WAD by exploring first receivers response to CBRN scenario cards. The responses were converted to HTAs and compared. The WAI HTAs showed 4-8 phases of general organizational responsibilities during a CBRN event. WAD HTAs placed emphasis on diagnosing and treating presenting conditions. A comparison of WAI and WAD HTAs highlighted common actions and tasks. This study has identified three key differences between WAI and WAD in the ED CBRN response: 1) documentation of the CBRN event 2) treating the patient and 3) diagnosing the presenting complaint. Findings from this study provide an evidence base which can be used to inform future clinical policy and practice in providing safe and high quality care during CBRN events in the ED

    Does the majority always know best? Young children's flexible trust in majority opinion

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    Copying the majority is generally an adaptive social learning strategy but the majority does not always know best. Previous work has demonstrated young children's selective uptake of information from a consensus over a lone dissenter. The current study examined children's flexibility in following the majority: do they overextend their reliance on this heuristic to situations where the dissenting individual has privileged knowledge and should be trusted instead? Four- to six- year-olds (N = 103) heard conflicting claims about the identity of hidden drawings from a majority and a dissenter in two between-subject conditions: in one, the dissenter had privileged knowledge over the majority (he drew the pictures); in the other he did not (they were drawn by an absent third party). Overall, children were less likely to trust the majority in the Privileged Dissenter condition. Moreover, 5- and 6- year-olds made majority-based inferences when the dissenter had no privileged knowledge but systematically endorsed the dissenter when he drew the pictures. The current findings suggest that by 5 years, children are able to make an epistemic-based judgment to decide whether or not to follow the majority rather than automatically following the most common view

    Nest Usurping Occurrence Of The Piratic Flycatcher (Legatus Leucophaius) In Southwestern Costa Rica

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    El Mosquerito Pirata (Legatus leucophaius) roba nidos colgantes o en forma de domo hechos principalmente por tiranidos o icteridos, sin embargo la frecuencia con la cual este mosquero se roba los nidos de otras especies es poco conocido. El Mosquerito Pirata robó nidos terminados de los Mosqueros Social (Myiozetetes similis) y Cabezigris (M. granadensis), construidos en sitios abiertos entre 5 – 9 m de alto. Nidos de otras especies con características similares pero menos abundantes o defendidos agresivamente, no fueron robados por el Mosquerito Piratas. A lo largo de su distribución reproductiva, son registrados usurpaciones de nidos por el Mosquerito Pirata en especies de al menos de cinco familias de aves.The Piratic Flycatcher (Legatus leucophaius) usurps pensile or domed nests mainly of other flycatchers (Tyrannidae) and icterids (Icteridae), but the frequency of nest parasitism is little known. In our study in south-west Costa Rica, the Piratic Flycatcher took over the finished domed nests of the Social (Myiozetetes similis) and the Gray-capped Flycatcher (M. granadensis), constructed in open sites between 5–9 m height. Nests of other species with similar characteristics, but less abundant or defended more aggressively, were not parasitized by the Piratic Flycatcher. Throughout its breeding range, nest usurpations by the Pyratic Flycatcher have been recorded for species belonging to at least five bird families.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

    Religiosity and decreased risk of substance use disorders: is the effect mediated by social support or mental health status?

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    The negative association between religiosity (religious beliefs and church attendance) and the likelihood of substance use disorders is well established, but the mechanism(s) remain poorly understood. We investigated whether this association was mediated by social support or mental health status. We utilized cross-sectional data from the 2002 National Survey on Drug Use and Health (n = 36,370). We first used logistic regression to regress any alcohol use in the past year on sociodemographic and religiosity variables. Then, among individuals who drank in the past year, we regressed past year alcohol abuse/dependence on sociodemographic and religiosity variables. To investigate whether social support mediated the association between religiosity and alcohol use and alcohol abuse/dependence we repeated the above models, adding the social support variables. To the extent that these added predictors modified the magnitude of the effect of the religiosity variables, we interpreted social support as a possible mediator. We also formally tested for mediation using path analysis. We investigated the possible mediating role of mental health status analogously. Parallel sets of analyses were conducted for any drug use, and drug abuse/dependence among those using any drugs as the dependent variables. The addition of social support and mental health status variables to logistic regression models had little effect on the magnitude of the religiosity coefficients in any of the models. While some of the tests of mediation were significant in the path analyses, the results were not always in the expected direction, and the magnitude of the effects was small. The association between religiosity and decreased likelihood of a substance use disorder does not appear to be substantively mediated by either social support or mental health status

    Temporal reliability of cytokines and growth factors in EDTA plasma

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    Background. Cytokines are involved in the development of chronic diseases, including cancer. It is important to evaluate the temporal reproducibility of cytokines in plasma prior to conducting epidemiologic studies utilizing these markers. Findings. We assessed the temporal reliability of CRP, 22 cytokines and their soluble receptors (IL-1α, ILβ-1, IL-1RA, IL-2, sIL-2R, IL-4, IL-5, IL-6, sIL-6R, IL-7, IL-8, IL-10, IL-12p40, IL-12p70, IL-13, IL-15, IL-17, TNFα, sTNF-R1, sTNF-R2, IFNα, IFNγ) and eight growth factors (GM-CSF, EGF, bFGF, G-CSF, HGF, VEGF, EGFR, ErbB2) in repeated EDTA plasma samples collected an average of two years apart from 18 healthy women (age range: 42-62) enrolled in a prospective cohort study. We also estimated the correlation between serum and plasma biomarker levels using 18 paired clinical samples from postmenopausal women (age range: 75-86). Twenty-six assays were able to detect their analytes in at least 70% of samples. Of those 26 assays, we observed moderate to high intra-class correlation coefficients (ICCs)(ranging from 0.53-0.89) for 22 assays, and low ICCs (0-0.47) for four assays. Serum and plasma levels were highly correlated (r > 0.6) for most markers, except for seven assays (r < 0.5). Conclusions. For 22 of the 31 biomarkers, a single plasma measurement is a reliable estimate of a woman's average level over a two-year period. © 2010 Clendenen et al; licensee BioMed Central Ltd

    Intimate partner violence among women with HIV infection in rural Uganda: critical implications for policy and practice

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    <p>Abstract</p> <p>Background</p> <p>Intimate partner violence (IPV) is a major public health problem in Africa and worldwide. HIV infected women face increased IPV risk. We assessed the prevalence and factors associated with IPV among HIV infected women attending HIV care in Kabale hospital, Uganda.</p> <p>Methods</p> <p>This cross-sectional study was conducted among 317 HIV infected women attending Kabale regional hospital HIV treatment centre, from March to December 2010. Participants were interviewed using an interviewer-administered questionnaire. Data was collected on socio-demographic variables, social habits, and IPV (using the abuse assessment screen and the Severity of Violence against Women Scale to identify physical, sexual and psychological violence). Characteristics of the participants who reported IPV were compared with those who did not. Multivariate logistic-regression analysis was conducted to analyze factors that were independently associated with IPV.</p> <p>Results</p> <p>The mean age of 317 respondents was 29.7 years. Twenty two (6.9%) were adolescents and 233 (73.5%) were married or cohabiting. The mean age of the spouse was 33.0 years.</p> <p>One hundred and eleven (35.0%) were currently on antiretroviral therapy. Lifetime prevalence of IPV (physical or sexual) was 36.6%. In the preceding 12 months, IPV (any type) was reported by 93 respondents (29.3%). This was physical for 55 (17.6%), and sexual /psychological for 38 (12.1%). On multivariate multinomial logistic regression analysis, there was a significant but inverse association between education level and physical partner violence (adjusted relative risk (ARR) 0.50, confidence limits (95% CI) 0.31-0.82, p-value = 0.007). There was a significant but inverse association between education level of respondent and sexual/psychological violence (ARR 0.47 95%CI (0.25-0.87), p-value = 0.017) Likewise, there was a significant inverse association between the education level of the spouse and psychological/sexual violence (ARR 0.57, 95% CI 0.25-0.90, p-value = 0.018). Use of antiretroviral therapy was associated with increased prevalence of any type of violence (physical, sexual or psychological) with ARR 3.04 (95%CI 1.15-8.45, p-value = 0.032).</p> <p>Conclusion</p> <p>Almost one in three women living with HIV had suffered intimate partner violence in the preceding 12 months. Nearly one in five HIV patients reported physical violence, and about one in every seven HIV patients reported sexual/psychological violence. Likewise, women who were taking antiretroviral drugs for HIV treatment were more likely to report any type of intimate partner violence (physical, sexual or psychological). The implication of these findings is that women living with HIV especially those on antiretroviral drugs should be routinely screened for intimate partner violence.</p

    Genomic and biological characterization of chiltepin yellow mosaic virus, a new tymovirus infecting Capsicum annuum var. aviculare in Mexico.

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    The characterization of viruses infecting wild plants is a key step towards understanding the ecology of plant viruses. In this work, the complete genomic nucleotide sequence of a new tymovirus species infecting chiltepin, the wild ancestor of Capsicum annuum pepper crops, in Mexico was determined, and its host range has been explored. The genome of 6,517 nucleotides has the three open reading frames described for tymoviruses, putatively encoding an RNA-dependent RNA polymerase, a movement protein and a coat protein. The 5′ and 3′ untranslated regions have structures with typical signatures of the tymoviruses. Phylogenetic analyses revealed that this new virus is closely related to the other tymoviruses isolated from solanaceous plants. Its host range is mainly limited to solanaceous species, which notably include cultivated Capsicum species. In the latter, infection resulted in a severe reduction of growth, indicating the potential of this virus to be a significant crop pathogen. The name of chiltepin yellow mosaic virus (ChiYMV) is proposed for this new tymovirus
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