365 research outputs found

    Caching and Interpolated Likelihoods: Accelerating Cosmological Monte Carlo Markov Chains

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    We describe a novel approach to accelerating Monte Carlo Markov Chains. Our focus is cosmological parameter estimation, but the algorithm is applicable to any problem for which the likelihood surface is a smooth function of the free parameters and computationally expensive to evaluate. We generate a high-order interpolating polynomial for the log-likelihood using the first points gathered by the Markov chains as a training set. This polynomial then accurately computes the majority of the likelihoods needed in the latter parts of the chains. We implement a simple version of this algorithm as a patch (InterpMC) to CosmoMC and show that it accelerates parameter estimatation by a factor of between two and four for well-converged chains. The current code is primarily intended as a "proof of concept", and we argue that there is considerable room for further performance gains. Unlike other approaches to accelerating parameter fits, we make no use of precomputed training sets or special choices of variables, and InterpMC is almost entirely transparent to the user.Comment: v2 Trivial Latex change. Source code: http://easther.physics.yale.edu/interpmc.htm

    Primary Caregivers of Children Affected by Disorders of Sex Development: Mental Health and Caregiver Characteristics in the Context of Genital Ambiguity and Genitoplasty

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    Purpose. To determine the relationship between having a child with a DSD including ambiguous external genitalia, as well as the decision of whether or not to have early genitoplasty for that child, on the mental health and parenting characteristics of caregivers. Materials and Methods. Caregivers were recruited from centers that specialize in DSD medicine and completed the Beck Depression Inventory 2nd Edition (BDI-2), Beck Anxiety Index (BAI), Parent Protection Scale (PPS), Child Vulnerability Scale (CVS) and Parenting Stress Index/Short Form (PSI/SF). Results and Conclusions. Sixty-eight caregivers provided informed consent and completed the study. Among female caregivers whose children never received genitoplasty, greater parenting stress was reported (F(1, 40) = 5.08, p = .03). For male caregivers, those whose children received genitoplasty within the first year of life reported more overprotective parenting and parenting stress than those whose children received genitoplasty later than 12 months of age (F(1, 13) = 6.16, p = 0.28); F(1, 15) = 6.70, p = .021), respectively)

    Long‐term monitoring and experimental manipulation of a Chihuahuan desert ecosystem near Portal, Arizona (1977–2013)

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    Desert ecosystems have long served as model systems in the study of ecological concepts (e.g., competition, resource pulses, top‐down/bottom‐up dynamics). However, the inherent variability of resource availability in deserts, and hence consumer dynamics, can also make them challenging ecosystems to understand. Study of a Chihuahuan desert ecosystem near Portal, Arizona began in 1977. At this site, 24 experimental plots were established and divided among controls and experimental manipulations. Experimental manipulations over the years include removal of all or some rodent species, all or some ants, seed additions, and various alterations of the annual plant community. This dataset includes data previously available through an older data publication and adds 11 years of data. It also includes additional ant and weather data not previously available. These data have been used in a variety of publications documenting the effects of the experimental manipulations as well as the response of populations and communities to long‐term changes in climate and habitat. Sampling is ongoing and additional data will be published in the future.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146431/1/ecy1360.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146431/2/ecy1360_am.pd

    Researching Intimacies and New Media:Methodological Opportunities and Challenges

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    Researching intimacies and new media encompasses a wide variety of intersecting practices and relationships. This special issue presents contributions from researchers who are investigating practices of intimacy mediated either wholly or in part through new media in which a variety of different methodological opportunities and challenges are highlighted and discussed. Existing research has addressed different combinations of new media, intimacy, and methodology, but there remains space for a dedicated focus on the ways in which these areas are interrelated and entangled. The articles in this special issue build up a conversation around this particular intersection from a range of directions, from reflections on specific technological devices/apps and their promotion of particular forms of intimacies that may lead to (dis)comfort and (dis)connection, to the intimate—and sometimes risky—investments in research processes and fieldwork, as well as the ethical frameworks and decision-making processes guiding the research

    Newborn screening for Pompe disease in Illinois: Experience with 684,290 infants

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    Statewide newborn screening for Pompe disease began in Illinois in 2015. As of 30 September 2019, a total of 684,290 infants had been screened and 395 infants (0.06%) were screen positive. A total of 29 cases of Pompe disease were identified (3 infantile, 26 late-onset). While many of the remainder were found to have normal alpha-glucosidase activity on the follow-up testing (234 of 395), other findings included 62 carriers, 39 infants with pseudodeficiency, and eight infants who could not be given a definitive diagnosis due to inconclusive follow-up testing

    Stellar Spin-Orbit Misalignment in a Multiplanet System

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    Stars hosting hot Jupiters are often observed to have high obliquities, whereas stars with multiple co-planar planets have been seen to have low obliquities. This has been interpreted as evidence that hot-Jupiter formation is linked to dynamical disruption, as opposed to planet migration through a protoplanetary disk. We used asteroseismology to measure a large obliquity for Kepler-56, a red giant star hosting two transiting co-planar planets. These observations show that spin-orbit misalignments are not confined to hot-Jupiter systems. Misalignments in a broader class of systems had been predicted as a consequence of torques from wide-orbiting companions, and indeed radial-velocity measurements revealed a third companion in a wide orbit in the Kepler-56 system.Comment: Accepted for publication in Science, published online on October 17 2013; PDF includes main article and supplementary materials (65 pages, 27 figures, 7 tables); v2: small correction to author lis

    Contacts and behaviours of university students during the COVID-19 pandemic at the start of the 2020/2021 academic year

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    University students have unique living, learning and social arrangements which may have implications for infectious disease transmission. To address this data gap, we created CONQUEST (COroNavirus QUESTionnaire), a longitudinal online survey of contacts, behaviour, and COVID-19 symptoms for University of Bristol (UoB) staff/students. Here, we analyse results from 740 students providing 1261 unique records from the start of the 2020/2021 academic year (14/09/2020–01/11/2020), where COVID-19 outbreaks led to the self-isolation of all students in some halls of residences. Although most students reported lower daily contacts than in pre-COVID-19 studies, there was heterogeneity, with some reporting many (median = 2, mean = 6.1, standard deviation = 15.0; 8% had ≥ 20 contacts). Around 40% of students’ contacts were with individuals external to the university, indicating potential for transmission to non-students/staff. Only 61% of those reporting cardinal symptoms in the past week self-isolated, although 99% with a positive COVID-19 test during the 2 weeks before survey completion had self-isolated within the last week. Some students who self-isolated had many contacts (mean = 4.3, standard deviation = 10.6). Our results provide context to the COVID-19 outbreaks seen in universities and are available for modelling future outbreaks and informing policy

    Refractory testicular germ cell tumors are highly sensitive to the second generation DNA methylation inhibitor guadecitabine

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    Testicular germ cell tumors (TGCTs) are the most common cancers of young males. A substantial portion of TGCT patients are refractory to cisplatin. There are no effective therapies for these patients, many of whom die from progressive disease. Embryonal carcinoma (EC) are the stem cells of TGCTs. In prior in vitro studies we found that EC cells were highly sensitive to the DNA methyltransferase inhibitor, 5-aza deoxycytidine (5-aza). Here, as an initial step in bringing demethylation therapy to the clinic for TGCT patients, we evaluated the effects of the clinically optimized, second generation demethylating agent guadecitabine (SGI-110) on EC cells in an animal model of cisplatin refractory testicular cancer. EC cells were exquisitely sensitive to guadecitabine and the hypersensitivity was dependent on high levels of DNA methyltransferase 3B. Guadecitabine mediated transcriptional reprogramming of EC cells included induction of p53 targets and repression of pluripotency genes. As a single agent, guadecitabine completely abolished progression and induced complete regression of cisplatin resistant EC xenografts even at doses well below those required to impact somatic solid tumors. Low dose guadecitabine also sensitized refractory EC cells to cisplatin in vivo. Genome-wide analysis indicated that in vivo antitumor activity was associated with activation of p53 and immune-related pathways and the antitumor effects of guadecitabine were dependent on p53, a gene rarely mutated in TGCTs. These preclinical findings suggest that guadecitabine alone or in combination with cisplatin is a promising strategy to treat refractory TGCT patients
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