571 research outputs found

    Short-term variations of Icelandic ice cap mass inferred from cGPS coordinate time series

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    As the global climate changes, understanding short-term variations in water storage is increasingly important. Continuously operating Global Positioning System (cGPS) stations in Iceland record annual periodic motion—the elastic response to winter accumulation and spring melt seasons—with peak-to-peak vertical amplitudes over 20 mm for those sites in the Central Highlands. Here for the first time for Iceland, we demonstrate the utility of these cGPS-measured displacements for estimating seasonal and shorter-term ice cap mass changes. We calculate unit responses to each of the five largest ice caps in central Iceland at each of the 62 cGPS locations using an elastic half-space model and estimate ice mass variations from the cGPS time series using a simple least squares inversion scheme. We utilize all three components of motion, taking advantage of the seasonal motion recorded in the horizontal. We remove secular velocities and accelerations and explore the impact that seasonal motions due to atmospheric, hydrologic, and nontidal ocean loading have on our inversion results. Our results match available summer and winter mass balance measurements well, and we reproduce the seasonal stake-based observations of loading and melting within the 1 math formula confidence bounds of the inversion. We identify nonperiodic ice mass changes associated with interannual variability in precipitation and other processes such as increased melting due to reduced ice surface albedo or decreased melting due to ice cap insulation in response to tephra deposition following volcanic eruptions, processes that are not resolved with once or twice-yearly stake measurements

    An algebra and a logic for NC1

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    Presented here are an algebra and a logic characterizing the complexity class NC1, which consists of functions computed by uniform families of polynomial size, log depth circuits. In both characterizations, NC1 functions are regarded as functions from one class of finite relational structures to another. In the algebraic characterization a recursion scheme called upward tree recursion is applied to a class of simple functions. In the logical characterization, first-order logic is augmented by an operator for defining relations by primitive recursion where it is assumed that every structure has an underlying relation BIT giving the binary representations of integers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28501/1/0000298.pd

    Dipoles in the Sky

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    We perform observational tests of statistical isotropy using data from large-scale structure surveys spanning a wide range of wavelengths. Using data from 2MASS, 2MRS, and NVSS galaxies, and BATSE gamma-ray bursts, we constrain the amplitude and direction of dipolar modulations in the number count of sources projected along the line of sight. We pay particular attention to the treatment of systematic errors and selection effects, and carefully distinguish between different sources of dipole signal previously considered in the literature. Dipole signals detected in these surveys are consistent with the standard, statistically isotropic expectation, except for the NVSS result, which is likely biased by remaining systematics in the data. We place constraints on the amplitude of any intrinsic dipole driven by novel physics in the early universe.Comment: 36 pages, 20 figures. v3: minor additions to theory section; matches the published MNRAS versio

    Agreeableness, antagonism, and mental health across cultures

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    This chapter reviews evidence about Agreeableness and antagonism and their association with mental health across cultures. Agreeableness is a personality dimension defined in a Western context, but which corresponds to a reasonable degree with indigenous dimensions found in other cultural settings. Studies translating Western measures into other languages have found similar factor structures, but not evidence for scalar measurement invariance, which would allow for reliable comparison of scores across cultural and linguistic settings. Interestingly, however, lower average scores for men versus women appear to be more pronounced in industrialized nations with greater gender equity. Agreeableness appears to increase with age across cultures, in particular around the time of taking on adult financial responsibilities. The symptoms and disorders associated with antagonism, including conduct disorder, aggression, psychopathy, antisocial personality disorder, substance use disorders, and borderline personality disorder, generally appear to be globally comprehensible and diagnosable. However, specific symptom patterns can vary considerably, and rates of aggressive behavior and related symptoms appear to be more common in individualistic, industrialized cultures

    Rural Primary Care Providers’ Experiences and Knowledge Regarding LGBTQ Health in a Midwestern State

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    PurposeHealth disparities among LGBTQ people have been documented across various settings and recent research has indicated that many disparities are heightened in the context of rurality. Among these disparities is the decreased rate of primary care utilization by rural LGBTQ individuals. Understanding and addressing provider knowledge and attitudes related to LGBTQ health provides a relevant avenue for addressing underutilization.MethodsThe study presented was a mail‐out survey regarding rural primary care providers’ knowledge and experiences regarding LGBTQ health. Publicly available records were compiled to recruit a total sample of 113 primary care providers, at a response rate of 19.8%.FindingsA majority of respondents reported experience providing care to LGBTQ patients, while only slightly over half had received LGBTQ health education. Data analyses revealed significant associations between reported experiences and patient characteristics including religion, religiousness, age, length of time practicing in current provider role, and gender identity. Provider knowledge of LGBTQ health varied greatly across the items assessed. Provider profession (physician, nurse practitioner, physician assistant) and length of current county residence were significantly predictive of LGBTQ knowledge scores.ConclusionResults provide insight into rural health care for LGBTQ people. Preeminent findings were: (1) an existing need for LGBTQ health education, (2) variation in knowledge across content areas, and (3) association between knowledge, profession, and length of current county residence. Promotion of rural LGBTQ health may benefit by addressing identified gaps in current care.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149681/1/jrh12322.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149681/2/jrh12322_am.pd

    Germline SDHx variants modify breast and thyroid cancer risks in Cowden and Cowden-like syndrome via FAD/NAD-dependant destabilization of p53

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    Cowden syndrome (CS), a Mendelian autosomal-dominant disorder, predisposes to breast, thyroid and other cancers. Germline mutations in phosphatase and tensin homolog (PTEN) have been recently reported in 23% of a large series of classic CS. Here, we validated our small (n = 10) pilot study in a large patient series that germline variations in succinate dehydrogenase genes (SDHx) occur in 8% (49/608) of PTEN mutation-negative CS and CS-like (CSL) individuals (SDHvar+). None of these SDHx variants was found in 700 population controls (P < 0.0001). We then found that SDHx variants also occur in 6% (26/444) of PTEN mutation-positive (PTENmut+) CS/CSL individuals (PTENmut+/SDHvar+). Of 22 PTENmut+/SDHvar+ females, 17 had breast cancers compared with 34/105 PTENmut+ (P < 0.001) or 27/47 SDHvar+ patients (P = 0.06). Notably, individuals with SDHvar+ alone had the highest thyroid cancer prevalence (24/47) compared with PTENmut+ patients (27/105, P = 0.002) or PTENmut+/SDHvar+ carriers (6/22, P = 0.038). Patient-derived SDHvar+ lymphoblastoid cells had elevated cellular reactive oxygen species, highest in PTENmut+/SDHvar+ cells, correlating with apoptosis resistance. SDHvar+ cells showed stabilized and hyperactivated hypoxia inducible factor (HIF)1α signaling. Most interestingly, we also observed the loss of steady-state p53 in the majority of SDHvar+ cells. This loss of p53 was regulated by MDM2-independent NADH quinone oxidoreductase 1-mediated protein degradation, likely due to the imbalance of flavin adenine dinucleotide/nicotinamide adenine dinucleotide in SDHvar+ cells. Our data suggest the potential regulation of HIF1α, p53 and PTEN signaling by mitochondrial metabolism in CS/CSL tumorigenesis. Together, our findings suggest the importance of considering SDHx as candidate predisposing and modifier genes for CS/CSL-related malignancy risks, and a mechanism which suggests ways of therapeutic reversal or prevention

    Physics, Astrophysics and Cosmology with Gravitational Waves

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    Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version <http://www.livingreviews.org/lrr-2009-2

    Has Motivational Interviewing fallen into its own Premature Focus Trap?

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    Since the initial conception of the behaviour change method Motivational Interviewing, there has been a shift evident in epistemological, methodological and practical applications, from an inductive, process and practitioner-focussed approach to that which is more deductive, research-outcome, and confirmatory-focussed. This paper highlights the conceptual and practical problems of adopting this approach, including the consequences of assessing the what (deductive outcome-focussed) at the expense of the how (inductively process-focussed). We encourage a return to an inductive, practitioner and client-focussed MI approach and propose the use of Computer Assisted Qualitative Data Analysis Systems such as NVivo in research initiatives to support this aim

    Scoring of senescence signalling in multiple human tumour gene expression datasets, identification of a correlation between senescence score and drug toxicity in the NCI60 panel and a pro-inflammatory signature correlating with survival advantage in peritoneal mesothelioma

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    Background: Cellular senescence is a major barrier to tumour progression, though its role in pathogenesis of cancer and other diseases is poorly understood in vivo. Improved understanding of the degree to which latent senescence signalling persists in tumours might identify intervention strategies to provoke "accelerated senescence" responses as a therapeutic outcome. Senescence involves convergence of multiple pathways and requires ongoing dynamic signalling throughout its establishment and maintenance. Recent discovery of several new markers allows for an expression profiling approach to study specific senescence phenotypes in relevant tissue samples. We adopted a "senescence scoring" methodology based on expression profiles of multiple senescence markers to examine the degree to which signals of damage-associated or secretory senescence persist in various human tumours. Results: We first show that scoring captures differential induction of damage or inflammatory pathways in a series of public datasets involving radiotherapy of colon adenocarcinoma, chemotherapy of breast cancer cells, replicative senescence of mesenchymal stem cells, and progression of melanoma. We extended these results to investigate correlations between senescence score and growth inhibition in response to similar to 1500 compounds in the NCI60 panel. Scoring of our own mesenchymal tumour dataset highlighted differential expression of secretory signalling pathways between distinct subgroups of MPNST, liposarcomas and peritoneal mesothelioma. Furthermore, a proinflammatory signature yielded by hierarchical clustering of secretory markers showed prognostic significance in mesothelioma. Conclusions: We find that "senescence scoring" accurately reports senescence signalling in a variety of situations where senescence would be expected to occur and highlights differential expression of damage associated and secretory senescence pathways in a context-dependent manner
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