622 research outputs found

    Neutrinoless Double Beta Decay, the Inverted Hierarchy and Precision Determination of theta(12)

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    Ruling out the inverted neutrino hierarchy with neutrinoless double beta decay experiments is possible if a limit on the effective mass below the minimal theoretically possible value is reached. We stress that this lower limit depends strongly on the value of the solar neutrino mixing angle: it introduces an uncertainty of a factor of 2 within its current 3 sigma range. If an experiment is not background-free, a factor of two in effective mass corresponds to a combined factor of 16 improvement for the experimental parameters running time, detector mass, background level and energy resolution. Therefore, a more precise determination of theta(12) is crucial for the interpretation of experimental results and the evaluation of the potential and requirements for future experiments. We give the required half-lifes to exclude (and touch) the inverted hierarchy regime for all double beta decay isotopes with a Q-value above 2 MeV. The nuclear matrix elements from 6 different groups and, if available, their errors are used and compared. We carefully put the calculations on equal footing in what regards various convention issues. We also use our compilation of matrix elements to give the reachable values of the effective mass for a given half-life value.Comment: 26 pages, 6 figures. v2: error corrected (misprint in paper we took a value from), slightly modifying the result

    Novel splice variants associated with one of the zebrafish dnmt3 genes

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    BACKGROUND: DNA methylation and the methyltransferases are known to be important in vertebrate development and this may be particularly true for the Dnmt3 family of enzymes because they are thought to be the de novo methyltransferases. Mammals have three Dnmt3 genes; Dnmt3a, Dnmt3b, and Dnmt3L, two of which encode active enzymes and one of which produces an inactive but necessary cofactor. However, due to multiple promoter use and alternative splicing there are actually a number of dnmt3 isoforms present. Six different dnmt3 genes have recently been identified in zebrafish. RESULTS: We have examined two of the dnmt3 genes in zebrafish that are located in close proximity in the same linkage group and we find that the two genes are more similar to each other than they are to the other zebrafish dnmt3 genes. We have found evidence for the existence of several different splice variants and alternative splice sites associated with one of the two genes and have examined the relative expression of these genes/variants in a number of zebrafish developmental stages and tissues. CONCLUSION: The similarity of the dnmt3-1 and dnmt3-2 genes suggests that they arose due to a relatively recent gene duplication event. The presence of alternative splice and start sites, reminiscent of what is seen with the human DNMT3s, demonstrates strong parallels between the control/function of these genes across vertebrate species. The dynamic expression levels of these genes/variants suggest that they may well play a role in early development and this is particularly true for dnmt3-2-1 and dnmt3-1. dnmt3-2-1 is the predominantly expressed form prior to zygotic gene activation whereas dnmt3-1 predominates post zygotic gene activation suggesting a distinct developmental role for each

    Analysis and Interpretation of Results Based on Patient-Reported Outcomes

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    AbstractThis article is part of a series of manuscripts dealing with the incorporation of patient-reported outcomes (PROs) into clinical trials. The issues dealt with in this manuscript concern the common pitfalls to avoid in statistical analysis and interpretation of PROs. Specifically, the questions addressed by this manuscript involve the analysis pitfalls with PRO data in clinical trials and how can they be avoided (e.g.,missing data, multiplicity, null results etc.). The manuscript provides key literature for existing resources and proposes new guidelines

    Interpreting and Reporting Results Based on Patient-Reported Outcomes

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    AbstractThis article deals with the incorporation of patient-reported outcomes (PROs) into clinical trials and focuses on issues associated with the interpretation and reporting of PRO data. The primary focus and context of this information relates to the evidentiary support and reporting for a labeling or advertising claim of a PRO benefit for a new or approved pharmaceutical product. This manuscript focuses on issues associated with assessing clinical significance and common pitfalls to avoid in presenting results related to PROs. Specifically, the questions addressed by this manuscript involve: What are the best methods to assess clinical significance for PROs? How should investigators present PRO data most effectively in a Food and Drug Administration (FDA) application? In labeling or in a scientific publication? Guidelinesfor interpreting clinical significance of PROs and for comprehensively reporting on the methods, measures and results of clinical trials that incorporate PROs are important for clinicians, regulatory agencies, and most of all to patients. Clear specifications for considering a finding on a PRO measure, as clinically meaningful, need to be determined by instrument developers and psychometricians; they need to be reported for all clinical trials involving PRO end points. Clinical trial reports need to be comprehensive, clear, and sufficient to enable any reader to understand the methods, PRO measures, statistical analysis, and results

    Effects of Carpal Tunnel Syndrome on Dexterous Manipulation Are Grip Type-Dependent

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    Carpal tunnel syndrome (CTS) impairs sensation of a subset of digits. Although the effects of CTS on manipulation performed with CTS-affected digits have been studied using precision grip tasks, the extent to which CTS affects multi-digit force coordination has only recently been studied. Whole-hand manipulation studies have shown that CTS patients retain the ability to modulate multi-digit forces to object mass, mass distribution, and texture. However, CTS results in sensorimotor deficits relative to healthy controls, including significantly larger grip force and lower ability to balance the torques generated by the digits. Here we investigated the effects of CTS on multi-digit force modulation to object weight when manipulating an object with a variable number of fingers. We hypothesized that CTS patients would be able to modulate digit forces to object weight. However, as different grip types involve the exclusive use of CTS-affected digits (‘uniform’ grips) or a combination of CTS-affected and non-affected digits (‘mixed’ grips), we addressed the question of whether ‘mixed’ grips would reduce or worsen CTS-induced force coordination deficits. The former scenario would be due to adding digits with intact tactile feedback, whereas the latter scenario might occur due to a potentially greater challenge for the central nervous system of integrating ‘noisy’ and intact tactile feedback. CTS patients learned multi-digit force modulation to object weight regardless of grip type. Although controls exerted the same total grip force across all grip types, patients exerted significantly larger grip force than controls but only for manipulations with four and five digits. Importantly, this effect was due to CTS patients’ inability to change the finger force distribution when adding the ring and little fingers. These findings suggest that CTS primarily challenges sensorimotor integration processes for dexterous manipulation underlying the coordination of CTS-affected and non-affected digits

    Effects of Carpal Tunnel Syndrome on adaptation of multi-digit forces to object mass distribution for whole-hand manipulation

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    Background Carpal tunnel syndrome (CTS) is a compression neuropathy of the median nerve that results in sensorimotor deficits in the hand. Until recently, the effects of CTS on hand function have been studied using mostly two-digit grip tasks. The purpose of this study was to investigate the coordination of multi-digit forces as a function of object center of mass (CM) during whole-hand grasping. Methods Fourteen CTS patients and age- and gender-matched controls were instructed to grasp, lift, hold, and release a grip device with five digits for seven consecutive lifts while maintaining its vertical orientation. The object CM was changed by adding a mass at different locations at the base of the object. We measured forces and torques exerted by each digit and object kinematics and analyzed modulation of these variables to object CM at object lift onset and during object hold. Our task requires a modulation of digit forces at and after object lift onset to generate a compensatory moment to counteract the external moment caused by the added mass and to minimize object tilt. Results We found that CTS patients learned to generate a compensatory moment and minimized object roll to the same extent as controls. However, controls fully exploited the available degrees of freedom (DoF) in coordinating their multi-digit forces to generate a compensatory moment, i.e., digit normal forces, tangential forces, and the net center of pressure on the finger side of the device at object lift onset and during object hold. In contrast, patients modulated only one of these DoFs (the net center of pressure) to object CM by modulating individual normal forces at object lift onset. During object hold, however, CTS patients were able to modulate digit tangential force distribution to object CM. Conclusions Our findings suggest that, although CTS did not affect patients’ ability to perform our manipulation task, it interfered with the modulation of specific grasp control variables. This phenomenon might be indicative of a lower degree of flexibility of the sensorimotor system in CTS to adapt to grasp task conditions

    The Mayo Clinic Manuscript Series Relative to the Discussion, Dissemination, and Operationalization of the Food and Drug Administration Guidance on Patient-Reported Outcomes

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    AbstractPatient-reported outcomes (PROs) have become increasingly prevalent in clinical research and practice. On February 2, 2006, the Food and Drug Administration (FDA) released a draft guidance document with respect to incorporating PROs into clinical research endeavors which include FDA involvement. Researchers at the Mayo Clinic worked with FDA personnel and experts from academia, industry, clinical research, and clinical practice to facilitate discussion, dissemination, and operationalization of the FDA guidance document. This article introduces a manuscript series that resulted from this collective effort. Basic terms are definedand a précis of each article in the manuscript series is given. The ultimate conclusion to be drawn from this series is that, while the goals of assessing and analyzing PRO elements of clinical practice and research are challenging, there now exists a scientific foundation that makes achieving these goals feasible and the results credible. This is vitally important because after all, at the heart of all healthcare endeavors is the patient
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