90 research outputs found

    No Correlation Between Host Galaxy Metallicity and Gamma-Ray Energy Release for Long-Duration Gamma-Ray Bursts

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    We compare the redshifts, host galaxy metallicities, and isotropic (E_gamma,iso) and beaming-corrected (E_gamma) gamma-ray energy release of 16 long-duration gamma-ray bursts (LGRBs) at z < 1. From this comparison, we find no statistically significant correlation between host metallicity and redshift, E_gamma,iso, or E_gamma. These results are at odds with previous theoretical and observational predictions of an inverse correlation between gamma-ray energy release and host metallicity, as well as the standard predictions of metallicity-driven wind effects in stellar evolutionary models. We consider the implications that these results have for LGRB progenitor scenarios, and discuss our current understanding of the role that metallicity plays in the production of LGRBs.Comment: 13 pages, 1 figure; accepted to Astrophysical Journa

    Understanding the Antiproliferative Activity of Plant Extracts

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    Many plants possess medicinal properties. Some, such as the Pacific yew, have yielded chemotherapeutic drugs (taxanes). Scientists report that other extracts such as the leaves of Calendula officinalis (marigold), Vinca rosea (periwinkle), Viscum cruciatum (mistletoe), and Rosmarinus officinalis (rosemary) have anti-tumor activity. In most cases, the chemical components responsible for antiproliferative activity have not been identified and it is unclear if any individual components are as effective in isolation as they are in the context of the whole extract. Furthermore, in most cases, there are no data indicating whether these extracts have synergistic effects or cause negative reactions when used with other drugs. We are using HeLa (adenocarcinoma), RAW 264.7 (leukemia), HepG2 (hepatoma), MDA-MB-231 (adenocarcinoma), and human foreskin fibroblasts (HFF, non-tumorigenic) to test the antiproliferative activity of several plant extracts. We identified five extracts, grapeseed, guava, yew, juniper berry, and Vinca, that slow the growth of all five cell lines in a dose-dependent manner. We are using a variety of methods to understand the mechanism by which these extracts are blocking cell growth

    Associations of prenatal maternal depressive symptoms with cord blood glucocorticoids and child hair cortisol levels in the project viva and the generation R cohorts:a prospective cohort study

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    Background: Prior studies have reported conflicting results regarding the association of prenatal maternal depression with offspring cortisol levels. We examined associations of high levels of prenatal depressive symptoms with child cortisol biomarkers. Methods:In Project Viva (n = 925, Massachusetts USA), mothers reported their depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, cord blood glucocorticoids were measured at delivery, and child hair cortisol levels were measured in mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In the Generation R Study (n = 1644, Rotterdam, The Netherlands), mothers reported depressive symptoms using the Brief Symptom Inventory (BSI) during pregnancy, and child hair cortisol was measured at a mean (SD) age of 6.0 (0.5) years. We used cutoffs of ≥ 13 for the EPDS and &gt; 0.75 for the BSI to indicate high levels of prenatal depressive symptoms. We used multivariable linear regression models adjusted for child sex and age (at outcome), and maternal pre-pregnancy BMI, education, social support from friends/family, pregnancy smoking status, marital status, and household income to assess associations separately in each cohort. We also meta-analyzed childhood hair cortisol results from both cohorts. Results: 8.0% and 5.1% of women respectively experienced high levels of prenatal depressive symptoms in Project Viva and the Generation R Study. We found no associations between high levels of maternal depressive symptoms during pregnancy and child cortisol biomarkers in either cohort. Conclusions: The present study does not find support for the direct link between high levels of maternal depressive symptoms and offspring cortisol levels.</p

    Effectiveness of a symptom-clinic intervention delivered by general practitioners with an extended role for people with multiple and persistent physical symptoms in England:the Multiple Symptoms Study 3 pragmatic, multicentre, parallel-group, individually randomised controlled trial

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    BACKGROUND: People with multiple and persistent physical symptoms have impaired quality of life and poor experiences of health care. We aimed to evaluate the effectiveness of a community-based symptom-clinic intervention in people with multiple and persistent physical symptoms, hypothesising that this symptoms clinic plus usual care would be superior to usual care only.METHODS: The Multiple Symptoms Study 3 was a pragmatic, multicentre, parallel-group, individually randomised controlled trial conducted in 108 general practices in the UK National Health Service in four regions of England between Dec 6, 2018, and June 30, 2023. Participants were individually randomised (1:1) to the symptom-clinic intervention plus usual care or to usual care only via a computer-generated, pseudo-random list stratified by trial centre. Allocation was done by the trial statistician and concealed with a centralised, web-based randomisation system; masking participants was not possible due to the nature of the intervention. The symptom-clinic intervention was a sequence of up to four medical consultations that aimed to elicit a detailed clinical history, fully hear and validate the participant, offer rational explanations for symptoms, and assist the participant to develop ways of managing their symptoms; it was delivered by general practitioners with an extended role. The primary outcome was Patient Health Questionnaire-15 (PHQ-15) score 52 weeks after randomisation, analysed by intention to treat. The trial is registered on the ISRCTN registry (ISRCTN57050216).FINDINGS: 354 participants were randomly assigned; 178 (50%) were assigned to receive the community-based symptoms clinic plus usual care and 176 (50%) were assigned to receive usual care only. At the primary-outcome point of 52 weeks, PHQ-15 scores were 14·1 (SD 3·7) in the group receiving usual care and 12·2 (4·5) in the group receiving the intervention. The adjusted between-group difference of -1·82 (95% CI -2·67 to -0·97) was statistically significantly in favour of the intervention group (p&lt;0·0001). There were 39 adverse events in the group receiving usual care and 36 adverse events in the group receiving the intervention. There were no statistically significant between-group differences in the proportion of participants who had non-serious adverse events (-0·03, 95% CI -0·11 to 0·05) or serious adverse events (0·02, -0·02 to 0·07). No serious adverse event was deemed to be related to the trial intervention.INTERPRETATION: Our symptom-clinic intervention, which focused on explaining persistent symptoms to participants in order to support self-management, led to sustained improvement in multiple and persistent physical symptoms.FUNDING: UK National Institute for Health and Care Research.</p

    Physical Activity, Mental Health and Wellbeing of Adults within and during the Easing of COVID-19 Restrictions, in the United Kingdom and New Zealand

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    Physical activity (PA) participation was substantially reduced at the start of the COVID-19 pandemic. The purpose of this study was to assess the association between PA, mental health, and wellbeing during and following the easing of COVID-19 restrictions in the United Kingdom (UK) and New Zealand (NZ). In this study, 3363 adults completed online surveys within 2–6 weeks of initial COVID-19 restrictions (April/May 2020) and once restrictions to human movement had been eased. Outcome measures included the International Physical Activity Questionnaire Short-Form, Depression Anxiety and Stress Scale-9 (mental health) and World Health Organisation-5 Wellbeing Index. There were no differences in PA, mental health or wellbeing between timepoints (p > 0.05). Individuals engaging in moderate or high volume of PA had significantly better mental health (−1.1 and −1.7 units, respectively) and wellbeing (11.4 and 18.6 units, respectively) than individuals who engaged in low PA (p < 0.001). Mental health was better once COVID-19 restrictions were eased (p < 0.001). NZ had better mental health and wellbeing than the UK (p < 0.001). Participation in moderate-to-high volumes of PA was associated with better mental health and wellbeing, both during and following periods of COVID-19 containment, compared to participation in low volumes of PA. Where applicable, during the current or future pandemic(s), moderate-to-high volumes of PA should be encouraged

    GRB 090426: The Environment of a Rest-Frame 0.35-second Gamma-Ray Burst at Redshift z=2.609

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    We present the discovery of an absorption-line redshift of z = 2.609 for GRB 090426, establishing the first firm lower limit to a redshift for a gamma-ray burst with an observed duration of <2 s. With a rest-frame burst duration of T_90z = 0.35 s and a detailed examination of the peak energy of the event, we suggest that this is likely (at >90% confidence) a member of the short/hard phenomenological class of GRBs. From analysis of the optical-afterglow spectrum we find that the burst originated along a very low HI column density sightline, with N_HI < 3.2 x 10^19 cm^-2. Our GRB 090426 afterglow spectrum also appears to have weaker low-ionisation absorption (Si II, C II) than ~95% of previous afterglow spectra. Finally, we also report the discovery of a blue, very luminous, star-forming putative host galaxy (~2 L*) at a small angular offset from the location of the optical afterglow. We consider the implications of this unique GRB in the context of burst duration classification and our understanding of GRB progenitor scenarios.Comment: Submitted to MNRA

    Theory and description in African Linguistics: Selected papers from the 47th Annual Conference on African Linguistics

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    The papers in this volume were presented at the 47th Annual Conference on African Linguistics at UC Berkeley in 2016. The papers offer new descriptions of African languages and propose novel theoretical analyses of them. The contributions span topics in phonetics, phonology, syntax, semantics, and pragmatics and reflect the typological and genetic diversity of languages in Africa. Four papers in the volume examine Areal Features and Linguistic Reconstruction in Africa, and were presented at a special workshop on this topic held alongside the general session of ACAL

    Theory and description in African Linguistics: Selected papers from the 47th Annual Conference on African Linguistics

    Get PDF
    The papers in this volume were presented at the 47th Annual Conference on African Linguistics at UC Berkeley in 2016. The papers offer new descriptions of African languages and propose novel theoretical analyses of them. The contributions span topics in phonetics, phonology, syntax, semantics, and pragmatics and reflect the typological and genetic diversity of languages in Africa. Four papers in the volume examine Areal Features and Linguistic Reconstruction in Africa, and were presented at a special workshop on this topic held alongside the general session of ACAL

    Theory and description in African Linguistics: Selected papers from the 47th Annual Conference on African Linguistics

    Get PDF
    The papers in this volume were presented at the 47th Annual Conference on African Linguistics at UC Berkeley in 2016. The papers offer new descriptions of African languages and propose novel theoretical analyses of them. The contributions span topics in phonetics, phonology, syntax, semantics, and pragmatics and reflect the typological and genetic diversity of languages in Africa. Four papers in the volume examine Areal Features and Linguistic Reconstruction in Africa, and were presented at a special workshop on this topic held alongside the general session of ACAL

    Theory and description in African Linguistics: Selected papers from the 47th Annual Conference on African Linguistics

    Get PDF
    The papers in this volume were presented at the 47th Annual Conference on African Linguistics at UC Berkeley in 2016. The papers offer new descriptions of African languages and propose novel theoretical analyses of them. The contributions span topics in phonetics, phonology, syntax, semantics, and pragmatics and reflect the typological and genetic diversity of languages in Africa. Four papers in the volume examine Areal Features and Linguistic Reconstruction in Africa, and were presented at a special workshop on this topic held alongside the general session of ACAL
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