1,538 research outputs found

    Effects of Perceived Discrimination on the School Satisfaction of Brazilian High School Graduates

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    This paper analyzes the consequences of peer victimization for the satisfaction with schooling (“happiness”) of college-bound high school graduates in Brazil.  Several types of victimization are explored including discrimination due to race/ethnicity, socioeconomic status, gender, sexual orientation, religious affiliation, and disability. We compare the satisfaction with their schooling of students planning to head to college straight from high school and older students applying for college later in life (“nontraditional students”). We conclude that students who perceived that they had been discriminated against were more dissatisfied with their school experience than those who did not, ceteris paribus, and we relate level of dissatisfaction to type of discrimination. The older student evidence reveals that this dissatisfaction wanes with time and age, however. Our conclusions are based upon ordered logistic analyses of data for 2.4 million current high school seniors and 78.7 thousand older students drawn from the Exame Nacional do Ensino Médio questionnaire (ENEM)

    dartR v2: An accessible genetic analysis platform for conservation, ecology and agriculture

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    Innumerable approaches to analyse genetic data are now available to guide conservation, ecological and agricultural projects. However, streamlined and accessible tools are needed to bring these approaches within the reach of a broader user base. dartR was released in 2018 to lessen the intrinsic complexity of analysing single nucleotide polymorphisms (SNPs) and dominant markers (presence/absence of amplified sequence tags) by providing user-friendly data quality control and marker selection functions. dartR users have grown steadily since its release and provided valuable feedback on their interaction with the package allowing us to enhance dartR capabilities. Here, we present Version 2 of dartR. In this version, we substantially increased the number of available functions from 45 to 144. In addition to improved functionality, we focused on enhancing the user experience by extending plot customisation, function standardisation, increasing user support and function speed. dartR provides functions for various stages in analysing genetic data, from data manipulation to reporting. dartR provides many functions for importing, exporting and linking to other packages, to provide an easy-to-navigate conduit between data generation and analysis options already available via other packages. We also implemented simulation functions whose results can be analysed seamlessly with several other dartR functions. As more methods and approaches mature to inform conservation, we envision that accessible platforms to analyse genetic data will play a crucial role in translating science into practice

    Quenched Spin Tunneling and Diabolical Points in Magnetic Molecules: II. Asymmetric Configurations

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    The perfect quenching of spin tunneling first predicted for a model with biaxial symmetry, and recently observed in the magnetic molecule Fe_8, is further studied using the discrete phase integral (or Wentzel-Kramers-Brillouin) method. The analysis of the previous paper is extended to the case where the magnetic field has both hard and easy components, so that the Hamiltonian has no obvious symmetry. Herring's formula is now inapplicable, so the problem is solved by finding the wavefunction and using connection formulas at every turning point. A general formula for the energy surface in the vicinity of the diabolo is obtained in this way. This formula gives the tunneling apmplitude between two wells unrelated by symmetry in terms of a small number of action integrals, and appears to be generally valid, even for problems where the recursion contains more than five terms. Explicit results are obtained for the diabolical points in the model for Fe_8. These results exactly parallel the experimental observations. It is found that the leading semiclassical results for the diabolical points appear to be exact, and the points themselves lie on a perfect centered rectangular lattice in the magnetic field space. A variety of evidence in favor of this perfect lattice hypothesis is presented.Comment: Revtex; 4 ps figures; follow up to cond-mat/000311

    First Documented Pathologies in Tenontosaurus tilletti with Comments on Infection in Non-Avian Dinosaurs

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    In 2001, a nearly complete sub-adult Tenontosaurus tilletti was collected from the Antlers Formation (Aptian-Albian) of southeastern Oklahoma. Beyond its exceptional preservation, computed tomography (CT) and physical examination revealed this specimen has five pathological elements with four of the pathologies a result of trauma. Left pedal phalanx I-1 and left dorsal rib 10 are both fractured with extensive callus formation in the later stages of healing. Left dorsal rib 7 (L7) and right dorsal rib 10 (R10) exhibit impacted fractures compressed 26 mm and 24 mm, respectively. The fracture morphologies in L7 and R10 indicate this animal suffered a strong compressive force coincident with the long axis of the ribs. All three rib pathologies and the pathological left phalanx I-1 are consistent with injuries sustained in a fall. However, it is clear from the healing exhibited by these fractures that this individual survived the fall. In addition to traumatic fractures, left dorsal rib 10 and possibly left phalanx I-1 have a morphology consistent with post-traumatic infection in the form of osteomyelitis. The CT scans of left metacarpal IV revealed the presence of an abscess within the medullary cavity consistent with a subacute form of hematogenous osteomyelitis termed a Brodie abscess. This is only the second reported Brodie abscess in non-avian dinosaurs and the first documented occurrence in herbivorous dinosaurs. The presence of a Brodie abscess, known only in mammalian pathological literature, suggest mammalian descriptors for bone infection may be applicable to non-avian dinosaurs.We thank R. Cifelli, S. Westrop, and N. Czaplewski for reviewing early drafts of this manuscript. This research was funded by grants awarded to R. L. Cifelli by the American Chemical Society, Petroleum Research Fund (ACS-PRF#38572-AC8) and the National Science Foundation (DEB 9870173). Open Access Fees paid for whole or in part by the University of Oklahoma Libraries Open Initiatives.Ye

    COVID-19: Can we treat the mother without harming her baby?

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    First published online: 25 January 2021Medical care is predicated on ‘do no harm’, yet the urgency to find drugs and vaccines to treat or prevent COVID-19 has led to an extraordinary effort to develop and test new therapies. Whilst this is an essential cornerstone of a united global response to the COVID-19 pandemic, the absolute requirements for meticulous efficacy and safety data remain. This is especially pertinent to the needs of pregnant women; a group traditionally poorly represented in drug trials, yet a group at heightened risk of unintended adverse materno-fetal consequences due to the unique physiology of pregnancy and the life course implications of fetal or neonatal drug exposure. However, due to the complexities of drug trial participation when pregnant (be they vaccines or therapeutics for acute disease), many clinical drug trials will exclude them. Clinicians must determine the best course of drug treatment with a dearth of evidence from either clinical or preclinical studies, where at least in the short term they may be more focused on the outcome of the mother than of her offspring.Michael D. Wiese, Mary J. Berry, Pravin Hissaria, Jack R.T. Darby, and Janna L. Morriso

    Sun exposure behaviour, seasonal vitamin D deficiency, and relationship to bone health in adolescents

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    YesContext: Vitamin D is essential for bone health in adolescence, where there is rapid bone mineral content accrual. As cutaneous sun-exposure provides vitamin D, there is no recommended oral intake for UK adolescents. Objective: Assess seasonal vitamin D status and its contributors in white Caucasian adolescents, and examine bone health in those found deficient. Design: Prospective cohort study. Setting: Six schools in Greater Manchester, UK. Participants: 131 adolescents, 12–15 years. Intervention(s): Seasonal assessment of circulating 25-hydroxyvitamin D (25OHD), personal sunexposure and dietary vitamin D. Adolescents deficient (25OHD <10 ng/mL/25 nmol/L) in ≥one season underwent dual-energy X-ray absorptiometry (lumbar spine, femoral neck), with bone mineral apparent density (BMAD) correction for size, and peripheral quantitative computed tomography (distal radius) for volumetric (v)BMD. Main Outcome Measure: Serum 25OHD; BMD. Results: Mean 25OHD was highest in September: 24.1 (SD 6.9) ng/mL and lowest in January: 15.5 (5.9) ng/mL. Over the year, 16% were deficient in ≥one season and 79% insufficient (25OHD <20 ng/mL/50 nmol/L) including 28% in September. Dietary vitamin D was low year-round while personal sun-exposure was seasonal and predominantly across the school week. Holidays accounted for 17% variation in peak 25OHD (p<0.001). Nineteen adolescents underwent bone assessment, which showed low femoral neck BMAD versus matched reference data (p=0.0002), 3 with Z≤ -2.0 distal radius trabecular vBMD. Conclusions: Sun-exposure levels failed to provide adequate vitamin D, ~one-quarter adolescents insufficient even at summer-peak. Seasonal vitamin D deficiency was prevalent and those affected had low BMD. Recommendations on vitamin D acquisition are indicated in this age-group.The Bupa Foundation (Grant number TBF-M10-017)

    Higher bone resorption excretion in South Asian women vs. White Caucasians and increased bone loss with higher seasonal cycling of vitamin D: Results from the D-FINES cohort study

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    Few data exist on bone turnover in South Asian women and it is not well elucidated as to whether Western dwelling South Asian women have different bone resorption levels to that of women from European ethnic backgrounds. This study assessed bone resorption levels in UK dwelling South Asian and Caucasian women as well as evaluating whether seasonal variation in 25-hydroxyvitamin D [25(OH)D] is associated with bone resorption in either ethnic group. Data for seasonal measures of urinary N-telopeptide of collagen (uNTX) and serum 25(OH)D were analysed from n = 373 women (four groups; South Asian postmenopausal n = 44, South Asian premenopausal n = 50, Caucasian postmenopausal n = 144, Caucasian premenopausal n = 135) (mean (± SD) age 48 (14) years; age range 18–79 years) who participated in the longitudinal D-FINES (Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England) cohort study (2006–2007). A mixed between-within subjects ANOVA (n = 192) showed a between subjects effect of the four groups (P < 0.001) on uNTX concentration, but no significant main effect of season (P = 0.163). Bonferroni adjusted Post hoc tests (P ≤ 0.008) suggested that there was no significant difference between the postmenopausal Asian and premenopausal Asian groups. Season specific age-matched-pairs analyses showed that in winter (P = 0.04) and spring (P = 0.007), premenopausal Asian women had a 16 to 20 nmol BCE/mmol Cr higher uNTX than premenopausal Caucasian women. The (amplitude/mesor) ratio (i.e. seasonal change) for 25(OH)D was predictive of uNTX, with estimate (SD) = 0.213 (0.015) and 95% CI (0.182, 0.245; P < 0.001) in a non-linear mixed model (n = 154). This showed that individuals with a higher seasonal change in 25(OH)D, adjusted for overall 25(OH)D concentration, showed increased levels of uNTX. Although the effect size was smaller than for the amplitude/mesor ratio, the mesor for 25(OH)D concentration was also predictive of uNTX, with estimate (SD) = − 0.035 (0.004), and 95% CI (− 0.043, − 0.028; P < 0.001). This study demonstrates higher levels of uNTX in premenopausal South Asian women than would be expected for their age, being greater than same-age Caucasian women, and similar to postmenopausal Asian women. This highlights potentially higher than expected bone resorption levels in premenopausal South Asian women which, if not offset by concurrent increased bone formation, may have future clinical and public health implications which warrant further investigation. Individuals with a larger seasonal change in 25(OH)D concentration showed an increased bone resorption, an association which was larger than that of the 25(OH)D yearly average, suggesting it may be as important clinically to ensure a stable and steady 25(OH)D concentration, as well as one that is high enough to be optimal for bone health

    Hypovitaminosis D in dogs with spirocercosis

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    BACKGROUND : Spirocercosis in dogs is characterized by esophageal nodules that can undergo neoplastic transformation. Hypovitaminosis D has been associated with neoplasia formation. We hypothesized hypovitaminosis D in neoplastic spirocercosis and that it could be a risk factor for neoplastic transformation. OBJECTIVE : To measure and compare vitamin D status, assessed by serum 25-hydroxyvitamin D [25(OH)D] concentrations in non-neoplastic (n = 25) and neoplastic (n = 26) spirocercosis client-owned dogs and healthy dogs (n = 24). ANIMALS : Twenty-five non-neoplastic dogs, 26 neoplastic dogs, and 24 healthy dogs. METHODS : Fifty-one dogs were randomly selected from 119 dogs diagnosed with spirocercosis presenting to our hospital, and further divided into non-neoplastic or neoplastic groups. Exclusion criteria included dogs less than 1 year old, with concurrent diseases, received corticosteroids, or treated prophylactically for spirocercosis. Serum 25(OH)D concentration was measured by high-performance liquid chromatography. Spirocercosis dogs’ appetites were graded and compared. RESULTS : Serum 25(OH)D concentrations were significantly different among all groups (P < .001). 25-Hydroxyvitamin D concentrations were significantly lower in neoplastic group (median 30.7 nmol/L [range 14.7–62.2]) compared to nonneoplastic (median 52.7 nmol/L [range 19.1–129.7, P < .05]) and healthy groups (median 74.6 nmol/L [range 37.4–130.5, P < .005]). 25-hydroxyvitamin D concentrations were significantly lower in non-neoplastic spirocercosis dogs compared to healthy ones (P < .05). Neoplastic and non-neoplastic spirocercosis dogs had similar appetite scores (P = 1.0). 25- Hydroxyvitamin D concentrations were not significantly different between dogs with normal (P = .087) and abnormal (P = .125) appetites within neoplastic and non-neoplastic spirocercosis groups. CONCLUSIONS AND CLINICAL IMPORTANCE : Further studies are warranted to determine potential use of vitamin D treatment in spirocercosis and explore role of hypovitaminosis D in pathogenesis of malignant transformation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1939-1676hb2014mn201
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