1,282 research outputs found

    Muon g − 2 and related phenomenology in constrained vector-like extensions of the MSSM

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    We analyze two minimal supersymmetric constrained models with low-energy vector-like matter preserving gauge coupling unification. In one we add to the MSSM spectrum a pair 5+ 5¯ of SU(5), in the other a pair 10+ 10¯. We show that the muon g−2 anomaly can be explained in these models while retaining perturbativity up to the unification scale, satisfying electroweak and flavor precision tests and current LHC data. We examine also some related phenomenological features of the models, including Higgs mass, fine-tuning, dark matter and several LHC signatures. We stress that, at least for the 5+ 5¯ model, the parameter space consistent with g − 2 is entirely in reach of the LHC with a moderate increase in luminosity with respect to the current data set

    Constrained MSSM favoring new territories: The impact of new LHC limits and a 125 GeV Higgs boson

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    We present an updated and extended global analysis of the Constrained MSSM (CMSSM) taking into account new limits on supersymmetry from ~5/fb data sets at the LHC. In particular, in the case of the razor limit obtained by the CMS Collaboration we simulate detector efficiency for the experimental analysis and derive an approximate but accurate likelihood function. We discuss the impact on the global fit of a possible Higgs boson with mass near 125 GeV, as implied by recent data, and of a new improved limit on BR(B_s->\mu\mu). We identify high posterior probability regions of the CMSSM parameters as the stau-coannihilation and the A-funnel region, with the importance of the latter now being much larger due to the combined effect of the above three LHC results and of dark matter relic density. We also find that the focus point region is now disfavored. Ensuing implications for superpartner masses favor even larger values than before, and even lower ranges for dark matter spin-independent cross section, \sigma^{SI}_p<10^{-9} pb. We also find that relatively minor variations in applying experimental constraints can induce a large shift in the location of the best-fit point. This puts into question the robustness of applying the usual chisquare approach to the CMSSM. We discuss the goodness-of-fit and find that, while it is difficult to calculate a p-value, the g-2 constraint makes, nevertheless, the overall fit of the CMSSM poor. We consider a scan without this constraint, and we allow \mu\ to be either positive or negative. We find that the global fit improves enormously for both signs of \mu, with a slight preference for \mu<0 caused by a better fit to BR(b->s\gamma) and BR(B_s->\mu\mu).Comment: 24 pages, 17 figures. PRD-approved version; Higgs bounds case removed as obsolete in light of the Higgs discover

    Cowden syndrome and the associated Lhermitte-Duclos disease – Case presentation

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    We report a patient with features of Cowden syndrome (CS). A 35-year old woman has been suffering from headache, vertigo and mild imbalance since 2 years. Examination showed subtle mucocutaneous lesions: papillomatous papules on the gingival mucosa, a few verrucous acral skin lesions and macrocephaly. Magnetic resonance imaging (MRI) revealed a tumor of the left cerebellar hemisphere with “tiger-striped” pattern on T2-weighted image (T2WI), typical of Lhermitte-Duclos disease (LDD) – one of the pathognomonic but infrequent features of CS. A pathogenic de novo heterozygous PTEN mutation: c.49C&gt;T variant has been identified in exon 1 of the PTEN gene by sequencing

    Board governance and corporate performance

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    © 2017 The Authors. We examine the link between the monitoring capacity of the board and corporate performance of UK listed firms. We also investigate how firms use the flexibility offered by the voluntary governance regime to make governance choices. We find a strong positive association between the board governance index we construct and firm operating performance. Our results imply that adherence to the board-related recommendations of the UK Corporate Governance Code strengthens the board's monitoring capacity, potentially helping mitigate agency problems, but that investors do not value it correspondingly. Moreover, in contrast to prior UK findings suggesting efficient adoption of Code recommendations, we find that firms at times use the Code flexibility opportunistically, aiming to decrease the monitoring capacity of the board, which is followed by subsequent underperformance. This finding questions the effectiveness of the voluntary approach to governance regulation followed in the UK and in many countries around the world.Economic and Social Research Council. Grant Number: RES‐061‐25‐0416

    Plasma Neuronal Exosomal Levels of Alzheimer\u27s Disease Biomarkers in Normal Aging

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    Plasma neuronal exosomal levels of pathogenic Alzheimer\u27s disease (AD) proteins, cellular survival factors, and lysosomal proteins distinguish AD patients from control subjects, but changes in these exosomal proteins associated with normal aging have not been described for cognitively intact subjects. Plasma neuronal exosomal levels of P-T181-tau, P-S396-tau, Aβ1-42, cathepsin D, repressor element 1-silencing transcription factor, and neurogranin were quantified longitudinally in cognitively intact older adults using two samples collected at 3- to 11-year intervals. Except for P-S396-tau, exosomal protein levels changed significantly with aging, but were largely outside the range observed in AD patients

    Clinically Silent Alzheimer\u27s and Vascular Pathologies Influence Brain Networks Supporting Executive Function in Healthy Older Adults

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    Aging is associated with declines in executive function. We examined how executive functional brain systems are influenced by clinically silent Alzheimer’s disease (AD) pathology and cerebral white matter hyperintensities (WMHs). Twenty-nine younger adults and thirty-four cognitively normal older adults completed a working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Older adults further underwent lumbar cerebrospinal fluid (CSF) draw for assessment of AD pathology and FLAIR imaging for assessment of WMHs. Accurate working memory performance in both age groups was associated with high fronto-visual functional connectivity (fC). However, in older adults, higher expression of fronto-visual fC was linked with lower levels of clinically silent AD pathology. In addition, AD pathology and WMHs were each independently related to increased fMRI response in the left dorsolateral prefrontal cortex, a pattern associated with slower task performance. Our results suggest that clinically silent AD pathology is related to lower expression of a fronto-visual fC pattern supporting executive task performance. Further, our findings suggest that AD pathology and WMHs appear to be linked with ineffective increases in frontal response in CN older adults

    Edge-variational Graph Convolutional Networks for Uncertainty-aware Disease Prediction

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    There is a rising need for computational models that can complementarily leverage data of different modalities while investigating associations between subjects for population-based disease analysis. Despite the success of convolutional neural networks in representation learning for imaging data, it is still a very challenging task. In this paper, we propose a generalizable framework that can automatically integrate imaging data with non-imaging data in populations for uncertainty-aware disease prediction. At its core is a learnable adaptive population graph with variational edges, which we mathematically prove that it is optimizable in conjunction with graph convolutional neural networks. To estimate the predictive uncertainty related to the graph topology, we propose the novel concept of Monte-Carlo edge dropout. Experimental results on four databases show that our method can consistently and significantly improve the diagnostic accuracy for Autism spectrum disorder, Alzheimer's disease, and ocular diseases, indicating its generalizability in leveraging multimodal data for computer-aided diagnosis.Comment: Accepted to MICCAI 202
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