997,003 research outputs found

    Evolution of complex flowering strategies: an age- and size-structured integral projection model

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    We explore the evolution of delayed age- and size-dependent flowering in the monocarpic perennial Carlina vulgaris, by extending the recently developed integral projection approach to include demographic rates that depend on size and age. The parameterized model has excellent descriptive properties both in terms of the population size and in terms of the distributions of sizes within each age class. In Carlina the probability of flowering depends on both plant size and age. We use the parameterized model to predict this relationship, using the evolutionarily stable strategy (ESS) approach. Despite accurately predicting the mean size of flowering individuals, the model predicts a step-function relationship between the probability of flowering and plant size, which has no age component. When the variance of the flowering-threshold distribution is constrained to the observed value, the ESS flowering function contains an age component, but underpredicts the mean flowering size. An analytical approximation is used to explore the effect of variation in the flowering strategy on the ESS predictions. Elasticity analysis is used to partition the agespecific contributions to the finite rate of increase (u) of the survival-growth and fecundity components of the model. We calculate the adaptive landscape that defines the ESS and generate a fitness landscape for invading phenotypes in the presence of the observed flowering strategy. The implications of these results for the patterns of genetic diversity in the flowering strategy and for testing evolutionary models are discussed. Results proving the existence of a dominant eigenvalue and its associated eigenvectors in general size- and age-dependent integral projection models are presented

    Service delivery interventions to increase uptake of voluntary medical male circumcision for HIV prevention: A systematic review.

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    BackgroundVoluntary medical male circumcision (VMMC) remains an essential component of combination HIV prevention services, particularly in priority countries in sub-Saharan Africa. As VMMC programs seek to maximize impact and efficiency, and to support World Health Organization guidance, specific uptake-enhancing strategies are critical to identify.MethodsWe systematically reviewed the literature to evaluate the impact of service delivery interventions (e.g., facility layout, service co-location, mobile outreach) on VMMC uptake among adolescent and adult men. For the main effectiveness review, we searched for publications or conference abstracts that measured VMMC uptake or uptake of HIV testing or risk reduction counselling within VMMC services. We synthesized data by coding categories and outcomes. We also reviewed studies assessing acceptability, values/preferences, costs, and feasibility.ResultsFour randomized controlled trials and five observational studies were included in the effectiveness review. Studies took place in South Africa, Tanzania, Uganda, Zambia, and Zimbabwe. They assessed a range of service delivery innovations, including community-, school-, and facility-based interventions. Overall, interventions increased VMMC uptake; some successfully improved uptake among age-specific subpopulations, but urban-rural stratification showed no clear trends. Interventions that increased adult men's uptake included mobile services (compared to static facilities), home-based testing with active referral follow-up, and facility-based HIV testing with enhanced comprehensive sexual education. Six acceptability studies suggested interventions were generally perceived to help men choose to get circumcised. Eleven cost studies suggested interventions create economies-of-scale and efficiencies. Three studies suggested such interventions were feasible, improving facility preparedness, service quality and quantity, and efficiencies.ConclusionsInnovative changes in male-centered VMMC services can improve adult men's and adolescent boys' VMMC uptake. Limited evidence on interventions that enhance access and acceptability show promising results, but evidence gaps persist due to inconsistent intervention definition and delivery, due in part to contextual relevance and limited age disaggregation

    Gestational dating by metabolic profile at birth: a California cohort study.

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    BackgroundAccurate gestational dating is a critical component of obstetric and newborn care. In the absence of early ultrasound, many clinicians rely on less accurate measures, such as last menstrual period or symphysis-fundal height during pregnancy, or Dubowitz scoring or the Ballard (or New Ballard) method at birth. These measures often underestimate or overestimate gestational age and can lead to misclassification of babies as born preterm, which has both short- and long-term clinical care and public health implications.ObjectiveWe sought to evaluate whether metabolic markers in newborns measured as part of routine screening for treatable inborn errors of metabolism can be used to develop a population-level metabolic gestational dating algorithm that is robust despite intrauterine growth restriction and can be used when fetal ultrasound dating is not available. We focused specifically on the ability of these markers to differentiate preterm births (PTBs) (<37 weeks) from term births and to assign a specific gestational age in the PTB group.Study designWe evaluated a cohort of 729,503 singleton newborns with a California birth in 2005 through 2011 who had routine newborn metabolic screening and fetal ultrasound dating at 11-20 weeks' gestation. Using training and testing subsets (divided in a ratio of 3:1) we evaluated the association among PTB, target newborn characteristics, acylcarnitines, amino acids, thyroid-stimulating hormone, 17-hydroxyprogesterone, and galactose-1-phosphate-uridyl-transferase. We used multivariate backward stepwise regression to test for associations and linear discriminate analyses to create a linear function for PTB and to assign a specific week of gestation. We used sensitivity, specificity, and positive predictive value to evaluate the performance of linear functions.ResultsAlong with birthweight and infant age at test, we included 35 of the 51 metabolic markers measured in the final multivariate model comparing PTBs and term births. Using a linear discriminate analyses-derived linear function, we were able to sort PTBs and term births accurately with sensitivities and specificities of ≥95% in both the training and testing subsets. Assignment of a specific week of gestation in those identified as PTBs resulted in the correct assignment of week ±2 weeks in 89.8% of all newborns in the training and 91.7% of those in the testing subset. When PTB rates were modeled using the metabolic dating algorithm compared to fetal ultrasound, PTB rates were 7.15% vs 6.11% in the training subset and 7.31% vs 6.25% in the testing subset.ConclusionWhen considered in combination with birthweight and hours of age at test, metabolic profile evaluated within 8 days of birth appears to be a useful measure of PTB and, among those born preterm, of specific week of gestation ±2 weeks. Dating by metabolic profile may be useful in instances where there is no fetal ultrasound due to lack of availability or late entry into care

    Orbital parameters and evolutionary status of the highly-peculiar binary system HD 66051

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    The spectroscopic binary system HD 66051 (V414 Pup) consists of a highlypeculiar CP3 (HgMn) star and an A-type component. It also shows out-of-eclipsevariability that is due to chemical spots. This combination allows thederivation of tight constraints for the testing of time-dependent diffusionmodels. We analysed radial velocity and photometric data using two differentmethods to determine astrophysical parameters and the orbit of the system.Appropriate isochrones were used to derive the age of the system. The orbitalsolution and the estimates from the isochrones are in excellent agreement withthe estimates from a prior spectroscopic study. The system is very close to thezero-age main sequence and younger than 120 Myr. HD 66051 is a most importantspectroscopic binary system that can be used to test the predictions of thediffusion theory explaining the peculiar surface abundances of CP3 stars.Fil: Paunzen, E.. Masaryk University; República ChecaFil: Fedurco, M.. Masaryk University; República ChecaFil: Helminiak, K.G.. Masaryk University; República ChecaFil: Pintado, Olga Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentin

    Modelling the demographic impact of HIV/AIDS in South Africa and the likely impact of interventions

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    This paper describes an approach to incorporating the impact of HIV/AIDS and the effects of HIV/AIDS prevention and treatment programmes into a cohort component projection model of the South African population. The modelled HIV-positive population is divided into clinical and treatment stages, and it is demonstrated that the age profile and morbidity profile of the HIV-positive population is changing significantly over time. HIV/AIDS is projected to have a substantial demographic impact in South Africa. Prevention programmes - social marketing, voluntary counselling and testing, prevention of mother-to-child transmission and improved treatment for sexually transmitted diseases - are unlikely to reduce AIDS mortality significantly in the short term. However, more immediate reductions in mortality can be achieved when antiretroviral treatment is introduced.antiretroviral treatment, demographic impact, HIV/AIDS prevention, simulation model, South Africa

    INTELLECTUAL CAPITAL DISCLOSURE IN BANKING COMPANY AT INDONESIA STOCK EXCHANGE

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    Intellectual capital is one of intangible asset’s component that can provide an added value to the company. Intellectual capital disclosure in the company’s annual reports can help to provide a complete information for investors in predicting the performance of the company for making an economic decisions. In addition, intellectual capital disclosure can also show the good performance of a company to attract investors. Intellectual capital disclosure can be affected by several factors, such as leverage, profitability, company age, and listing age. This study aims to obtain empirical evidence and analyze the effect of leverage, profitability, company age, and listing age on intellectual capital disclosure. The sample used in this study are banking companies listed in Indonesia Stock Exchange. The number of samples in this study are 95 companies and selected using purposive sampling. Hypothesis testing are using multiple linear regression analysis. Based on the results of the hypothesis testing, the results of this study show that profitability, company age, and listing age have a significant positive effect on intellectual capital disclosure, while leverage have no significant effect on intellectual capital disclosure

    Archaeological Testing of Site 41BL301 Bell County, Texas

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    Testing of Site 41BL301 on FM 3467 in Bell County, Texas, was undertaken in May 1986 to assess the site\u27s potential for nomination as a State Archeological Landmark, and to determine site depth, cultural context and archaeological significance. The site is located along a second terrace on the south side of Nolan Creek in the western outskirts of Belton, Texas. The majority of the site lies outside the highway right-of-way along the terrace system. Results of the testing indicate that those portions of the site within the project limit contain a minimal prehistoric component--probably a lithic procurement source--of unknown age which is largely limited to the present ground surface. Subsurface testing with a hand-excavated unit and a Gradal1 failed to locate buried components

    Factors affecting the uptake of HIV testing among men: a mixed-methods study in rural burkina faso

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    Includes bibliographical references (page 13-15).Background This study aimed to explore factors shaping the decision to undergo Human Immunodeficiency Virus (HIV) testing among men in rural Burkina Faso. Methods The study took place in 2009 in the Nouna Health District and adopted a triangulation mixed methods design. The quantitative component relied on data collected through a structured survey on a representative sample of 1130 households. The qualitative component relied on 38 in-depth interviews, with men purposely selected to represent variation in testing decision, age, and place of residence. A two-part model was conducted, with two distinct outcome variables, i.e. “being offered an HIV test” and “having done an HIV test”. The qualitative data analysis relied on inductive coding conducted by three independent analysts. Result Of the 937 men, 357 had been offered an HIV test and 97 had taken the test. Younger age, household wealth, living in a village under demographic surveillance, and knowing that HIV testing is available at primary health facilities were all positively associated with the probability of being offered an HIV test. Household wealth and literacy were found to be positively associated, and distance was found to be negatively associated with the probability of having taken an HIV test. Qualitative findings indicated that the limited uptake of HIV testing was linked to poor knowledge on service availability and to low risk perceptions. Conclusion With only 10% of the total sample ever having tested for HIV, our study confirmed that male HIV testing remains unacceptably low in Sub-Saharan Africa. This results from a combination of health system factors, indicating general barriers to access, and motivational factors, such as one’s own knowledge of service availability and risk perceptions. Our findings suggested that using antenatal care and curative services as the exclusive entry points into HIV testing may not be sufficient to reach large portions of the male population. Thus, additional strategies are urgently needed to increase service uptake.Manuela De AllegriIsabelle AgierJustin TiendrebeogoValerie Renée LouisMaurice YéOlaf MuellerMalabika SarkerPublishe

    Archaeological Testing of Site 41BX679 Bexar County, Texas

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    Testing of Site 41BX679 along Farm to Market Highway 2696 in Bexar County, Texas, to determine eligibility for inclusion within the National Register of Historic Places, cultural context, and archaeological significance was undertaken in April 1985. The site is located along a slight rise between Cibolo Creek and Muesebach Creek in northern Bexar County. It has been disturbed by previous construction or cutting of fire lines along Camp Bullis military reservation. Results of testing indicate that 41BX679 contained a minimal prehistoric component of unknown age. An intact hearth was uncovered but associated lithic debitage was almost totally absent. Evidence recovered does not support a determination of eligibility for inclusion within the National Register of Historic Places

    The Orbit of the L dwarf + T dwarf Spectral Binary SDSS J080531.84+481233.0

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    [abridged] We report four years of radial velocity monitoring observations of SDSS J080531.84+481233.0 that reveal significant and periodic variability, confirming the binary nature of the source. We infer an orbital period of 2.02±\pm0.03 yr, a semi-major axis of 0.760.06+0.05^{+0.05}_{-0.06} AU, and an eccentricity of 0.46±\pm0.05, consistent with the amplitude of astrometric variability and prior attempts to resolve the system. Folding in constraints based on the spectral types of the components (L4±\pm0.7 and T5.5±\pm1.1), corresponding effective temperatures, and brown dwarf evolutionary models, we further constrain the orbital inclination of this system to be nearly edge-on (90o±^o\pm19o^o), and deduce a large system mass ratio (M2_2/M1_1 = 0.860.12+0.10^{+0.10}_{-0.12}), substellar components (M1_1 = 0.0570.014+0.016^{+0.016}_{-0.014} M_{\odot}, M2_2 = 0.0480.010+0.008^{+0.008}_{-0.010} M_{\odot}), and a relatively old system age (minimum age = 4.01.2+1.9^{+1.9}_{-1.2} Gyr). The measured projected rotational velocity of the primary (vsiniv\sin{i} = 34.1±\pm0.7 km/s) implies that this inactive source is a rapid rotator (period \lesssim 3 hr) and a viable system for testing spin-orbit alignment in very-low-mass multiples. The combination of well-determined component atmospheric properties and masses near and/or below the hydrogen minimum mass make SDSS J0805+4812AB an important system for future tests of brown dwarf evolutionary models.Comment: 15 pages, 11 figures, accepted for publication to Ap
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