298 research outputs found

    The b -> s gamma decay revisited

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    In this work we compute the leading logarithmic corrections to the b -> s gamma decay in a dimensional scheme which does not require any definition of the gamma5 matrix. The scheme does not exhibit unconsistencies and it is therefore a viable alternative to the t'Hooft Veltman scheme, particularly in view of the next-to-leading computation. We confirm the recent results of Ciuchini et al.Comment: 11 pages RevTeX + 2 EPSF figures, report IFUP-TH 2/94, HUTP-93/A038. PostScript file or hardcopy available from the authors upon reques

    Impaired Differentiation of Osteoclasts in TREM-2–deficient Individuals

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    TREM-2 is an immunoglobulin-like cell surface receptor associated with DAP12/KARAP that activates monocyte-derived dendritic cells (DCs) in vitro. Recently, it has been shown that genetic defects of human DAP12/KARAP and TREM-2 result in a rare syndrome characterized by bone cysts and presenile dementia called Nasu-Hakola disease. This observation suggests that TREM-2 may function in myeloid cells other than DCs, most probably osteoclasts (OCs) and microglial cells, which are involved in bone modeling and brain function. Consistent with this prediction, here we show that OC differentiation is dramatically arrested in TREM-2–deficient patients, resulting in large aggregates of immature OCs that exhibit impaired bone resorptive activity. These results demonstrate a critical role for TREM-2 in the differentiation of mononuclear myeloid precursors into functional multinucleated OCs

    Avoidant Coping and Self-efficacy Mediate Relationships between Perceived Social Constraints and Symptoms among Long-term Breast Cancer Survivors

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    Objective Many breast cancer survivors feel constrained in discussing their cancer experience with others. Limited evidence suggests that social constraints (e.g., avoidance and criticism) from loved ones may negatively impact breast cancer survivors' global health, but research has yet to examine relationships between social constraints and common physical symptoms. Informed by social cognitive processing theory, this study examined whether perceived social constraints from partners and healthcare providers (HCPs) were associated with fatigue, sleep disturbance, and attentional functioning among long-term breast cancer survivors (N = 1052). In addition, avoidant coping and self-efficacy for symptom management were examined as potential mediators of these relationships. Methods Long-term breast cancer survivors (mean years since diagnosis = 6) completed questionnaires assessing social constraints from partners and HCPs, avoidant coping, self-efficacy for symptom management, and symptoms (i.e., fatigue, sleep disturbance, and attentional functioning). Structural equation modeling was used to evaluate the hypothesized relationships among variables in two models: one focused on social constraints from partners and one focused on social constraints from HCPs. Results Both models demonstrated good fit. Consistent with theory and prior research, greater social constraints from both partners and HCPs were associated with greater symptom burden (i.e., greater fatigue and sleep disturbance, poorer attentional functioning). In addition, all relationships were mediated by avoidant coping and self-efficacy for symptom management. Conclusions Findings are consistent with social cognitive processing theory and suggest that symptom management interventions may be enhanced by addressing the impact of social constraints from survivors' partners and HCPs on their coping and self-efficacy

    The Relationship Between Depressive Symptoms and Social Cognitive Processing in Partners of Long-Term Breast Cancer Survivors

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    Purpose/Objectives: To determine 1) if depressive symptoms in partners of long-term breast cancer survivors (BCS) could be predicted by social cognitive processing theory, and 2) if partners of younger and older breast cancer survivors were differentially affected by the cancer experience. Design: A cross-sectional, descriptive study utilizing self-report questionnaires. Setting: Indiana University and 97 ECOG-ACRIN sites. Sample: Partners of breast cancer survivors (n=508) diagnosed 3-8 years prior. Methods: Secondary data mediation analyses were conducted to determine if cognitive processing mediated the relationship between social constraints and depressive symptoms. Age-related differences on all scales were tested. Main Research Variables: Depressive symptoms; secondary variables included social constraints, cognitive processing (avoidance and intrusive thoughts), and potentially confounding variables. Findings: Cognitive processing mediated the relationship between social constraints and depressive symptoms for partners (F(5,498)= 19.911, R2=.167, p<.001). Partners of young BCS reported worse outcomes on all measures than partners of older breast cancer survivors Conclusions: As predicted by the social cognitive processing theory, cognitive processing mediated the relationship between social constraints and depressive symptoms. Furthermore, partners of younger BCS fared worse on social constraints, intrusive thoughts and depressive symptoms than partners of older BCS. Implications for Nursing: Results provide support for using the social cognitive processing theory in intervention design with partners of long-term BCS to decrease depressive symptoms. Knowledge Translation: • Partners of long-term BCS report clinically significant depression. • Partners of younger BCS report higher levels of depressive symptoms than the national average and than partners of older survivors. • Addressing social constraints within the dyad may improve depressive symptoms.This study was coordinated by the ECOG-ACRIN Cancer Research Group (Robert L. Comis, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported in part by Public Health Service Grants CA189828, CA180795, CA37403, CA35199, CA17145 and CA49883, and from the National Cancer Institute, National Institutes of Health and the Department of Health and Human Services. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute. Research reported in this publication was supported by the National Institute of Nursing Research of the National Institutes of Health under Award Number F31NR013822, and by the National Cancer Institute of the National Institutes of Health under Award Numbers K05CA175048 and R25CA117865. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health, including the National Cancer Institute or the National Institute of Nursing Research

    Two-loop QCD corrections to charged-Higgs-mediated b→sγb\to s\gamma decay

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    The charged-Higgs-mediated contribution to the Wilson coefficient of the b→sγb\to s\gamma magnetic penguin is expected to be one of the more promising candidates for a supersymmetric effect in B physics, probably the only one in gauge-mediated models. We compute the two-loop QCD correction to it. With naive dimensional regularization and MSbar subtraction, for reasonable values of the charged Higgs mass and for mu-bar = m_top, we find a (10--20)% reduction of the corresponding one-loop effect.Comment: 10 pages, 2 figures. Misprints corrected. Comparison with hep-ph/9710335 adde

    Optimal detection of burst events in gravitational wave interferometric observatories

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    We consider the problem of detecting a burst signal of unknown shape. We introduce a statistic which generalizes the excess power statistic proposed by Flanagan and Hughes and extended by Anderson et al. The statistic we propose is shown to be optimal for arbitrary noise spectral characteristic, under the two hypotheses that the noise is Gaussian, and that the prior for the signal is uniform. The statistic derivation is based on the assumption that a signal affects only affects N samples in the data stream, but that no other information is a priori available, and that the value of the signal at each sample can be arbitrary. We show that the proposed statistic can be implemented combining standard time-series analysis tools which can be efficiently implemented, and the resulting computational cost is still compatible with an on-line analysis of interferometric data. We generalize this version of an excess power statistic to the multiple detector case, also including the effect of correlated noise. We give full details about the implementation of the algorithm, both for the single and the multiple detector case, and we discuss exact and approximate forms, depending on the specific characteristics of the noise and on the assumed length of the burst event. As a example, we show what would be the sensitivity of the network of interferometers to a delta-function burst.Comment: 21 pages, 5 figures in 3 groups. Submitted for publication to Phys.Rev.D. A Mathematica notebook is available at http://www.ligo.caltech.edu/~avicere/nda/burst/Burst.nb which allows to reproduce the numerical results of the pape

    Long-Term Fear of Recurrence in Young Breast Cancer Survivors and Partners

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    Background Fear of a breast cancer recurrence is the most prevalent and disruptive source of distress for long-term survivors and their partners. However, few studies have focused on predictors of fear of recurrence. The aim of this study is to test the efficacy of the Social Cognitive Processing Theory (SCPT) in predicting fear of recurrence in long-term breast cancer survivors diagnosed at age 45 years or younger and their partners. Methods In a large cross-sectional study, breast cancer survivors (n = 222) 3–8 years from diagnosis and their partners completed a survey assessing demographic characteristics, fear of recurrence, social constraints, and cognitive processing (intrusive thoughts and cognitive avoidance). Mediation analyses were conducted for survivors and partners separately to determine if cognitive processing would mediate the relationship between social constraints and fear of recurrence. Results Cognitive processing mediated the relationship between social constraints and fear of recurrence both for survivors [F(3,213) = 47.541, R2 = 0.401, p < 0.001] and partners [F(3,215) = 27.917, R2 = 0.280, p < 0.001). Demographic variables were not significant predictors of fear of recurrence. Conclusions As predicted, cognitive processing mediated the relationship between social constraints and fear of recurrence. Results expand the utility of the SCPT in long-term survivors and their partners by supporting its use in intervention design.Acknowledgement: This research was supported by an American Cancer Society grant: RSGPB-04-089-01-PBP. This study was coordinated by the ECOG-ACRIN Cancer Research Group (Robert L. Comis, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported in part by Public Health Service Grants CA189828, CA180795 and from the National Cancer Institute, National Institutes of Health and the Department of Health and Human Services. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute. Research reported in this publication was supported by the National Institute of Nursing Research of the National Institutes of Health under Award Number F31NR013822. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Research reported in this publication was supported by the National Cancer Institute of the National Institutes of Health under Award Number K05CA175048. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health

    Factors associated with depressive symptoms in young long-term breast cancer survivors

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    Purpose Long-term breast cancer survivors frequently report distress (i.e., depressive symptoms) that impacts their quality of life. Previous studies have found that negative social interactions (“social constraints”) from partners contribute to long-term, unresolved cycling of intrusive thoughts and cognitive avoidance, resulting in psychological distress. However, these relationships have not been tested in long-term breast cancer survivors. Furthermore, the effect of partners’ depressive symptoms on the survivors’ depressive symptoms has not been tested within the context of these relationships. Therefore, the purpose of this study was to test relationships between breast cancer survivors’ depressive symptoms and (1) social constraints, cognitive avoidance, and intrusive thoughts, and (2) partners’ depressive symptoms. Methods Data were from a cross-sectional descriptive study of breast cancer survivors (N = 222) 3–8 years post-diagnosis and their partners, who completed surveys assessing demographic characteristics, social constraints, intrusive thoughts, cognitive avoidance, and depressive symptoms. Structural equation modeling confirmatory path analyses were conducted to determine significant relationships between survivors’ depressive symptoms and all other variables. Results Our model fits the data well. Breast cancer survivors’ depressive symptoms were predicted by social constraints and intrusive thoughts. The relationship between survivors’ depressive symptoms and partners’ depressive symptoms was close but not significant. Conclusions As hypothesized, depressive symptoms were predicted by social constraints and intrusive thoughts. Further research is needed to understand the possible relationship between survivors’ long-term depressive symptoms and cognitive avoidance and partners’ depressive symptoms. Our findings highlight the negative impact of social constraints from partners on psychological outcomes in long-term breast cancer survivors

    Nanoscale molecular reorganization of the inhibitory postsynaptic density is a determinant of gabaergic synaptic potentiation

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    Gephyrin is a key scaffold protein mediating the anchoring of GABAA receptors at inhibitory synapses. Here, we exploited superresolution techniques combined with proximity-based clustering analysis and model simulations to investigate the single-molecule gephyrin reorganization during plasticity of inhibitory synapses in mouse hippocampal cultured neurons. This approach revealed that, during the expression of inhibitory LTP, the increase of gephyrin density at postsynaptic sites is associated with the promoted formation of gephyrin nanodomains. We demonstrate that the gephyrin rearrangement in nanodomains stabilizes the amplitude of postsynaptic currents, indicating that, in addition to the number of synaptic GABAA receptors, the nanoscale distribution of GABAA receptors in the postsynaptic area is a crucial determinant for the expression of inhibitory synaptic plasticity. In addition, the methodology implemented here clears the way to the application of the graph-based theory to single-molecule data for the description and quantification of the spatial organization of the synapse at the single-molecule level
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