665 research outputs found

    No difference in variability of unique hue selections and binary hue selections

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    If unique hues have special status in phenomenological experience as perceptually pure, it seems reasonable to assume that they are represented more precisely by the visual system than are other colors. Following the method of Malkoc et al. (J. Opt. Soc. Am. A22, 2154 [2005]), we gathered unique and binary hue selections from 50 subjects. For these subjects we repeated the measurements in two separate sessions, allowing us to measure test-retest reliabilities (0.52≀ρ≀0.78; pâ‰Ș0.01). We quantified the within-individual variability for selections of each hue. Adjusting for the differences in variability intrinsic to different regions of chromaticity space, we compared the within-individual variability for unique hues to that for binary hues. Surprisingly, we found that selections of unique hues did not show consistently lower variability than selections of binary hues. We repeated hue measurements in a single session for an independent sample of 58 subjects, using a different relative scaling of the cardinal axes of MacLeod-Boynton chromaticity space. Again, we found no consistent difference in adjusted within-individual variability for selections of unique and binary hues. Our finding does not depend on the particular scaling chosen for the Y axis of MacLeod-Boynton chromaticity space

    A new autoregressive time series model in exponential variables (NEAR(1))

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    A new time series model for exponential variables having first order autoregressive structure is presented. Unlike the recently studied standard autoregressive model in exponential variables (EAR(1)), runs of constantly scaled values are avoidable, and the two parameter structure allows some adjustment of time nonreversibility effects in sample path behavior. The model is further developed by the use of cross-coupling and antithetic ideas to allow negative dependency. Joint distributions and autocorrelations are investigated. A transformed version of the model has a uniform marginal distribution and its correlation and regression structures are also obtained. Estimation aspects of the models are briefly considered. (Author)Naval Postgraduate School, Monterey, CAhttp://archive.org/details/newautoregressiv00lawrN0001480WR0005

    A moving average exponential point process (EMA1)

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    A construction is given for a stationary sequence of random variables the set (X sub i) which have exponential marginal distributions and are random linear combinations of order one of an i.i.d. exponential sequence the set (epsilon sub i). The joint and trivariate exponential distributions of (X sub (i-1), (X sub i) and (X sub (i + 1)) are studied, as well as the intensity function, point spectrum and variance time curve for the point process which has the set (X sub i) sequence for successive times between events. Initial conditions to make the point process count stationary are given, and extensions to higher order moving averages and Gamma point processes are discussedsupported in part by the Office of Naval Research, the National Science Foundation and the United Kingdom Science Research Councilhttp://archive.org/details/movingaverageexp00lawrN

    Holographic Technidilaton and LHC searches

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    We analyze in detail the phenomenology of a model of dynamical electroweak symmetry breaking inspired by walking technicolor, by using the techniques of the bottom-up approach to holography. The model admits a light composite scalar state, the dilaton, in the spectrum. We focus on regions of parameter space for which the mass of such dilaton is 125 GeV, and for which the bounds on the precision electroweak parameter S are satisfied. This requires that the next-to-lightest composite state is the techni-rho meson, with a mass larger than 2.3 TeV. We compute the couplings controlling the decay rates of the dilaton to two photons and to two (real or virtual) Z and W bosons. For generic choices of the parameters, we find a suppression of the decay into heavy gauge bosons, in respect to the analog decay of the standard-model Higgs. We find a dramatic effect on the decay into photons, which can be both strongly suppressed or strongly enhanced, the latter case corresponding to the large-N regime of the dual theory. There is a correlation between this decay rate of the dilaton into photons and the mass splitting between the techni-rho meson and its axial-vector partner: if the decay is enhanced in respect to the standard-model case, then the heavy spin-1 resonances are nearly degenerate in mass, otherwise their separation in mass is comparable to the mass scale itself.Comment: Very minor typos corrected. References adde

    Chromosomal ampC mutations in cefpodoxime-resistant ESBL-negative uropathogenic escherichia coli

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    AmpC beta-lactamase is an enzyme commonly produced by Escherichia coli that causes resistance to cephalosporins and penicillins. Enzyme production is controlled by the strength of the promoter encoded by the chromosomal ampC gene, with the level of production affected by the presence of certain mutations in this region. This study sets out to determine the prevalence of ampC promoter mutations present in a group of uropathogenic E. coli strains. A total of 50 clinical strains of E. coli were collected from urine samples between June 2011 and November 2011. Strains were investigated for the presence of mutations in the chromosomal ampC promoter region by amplification and sequencing of a 271 bp product. The presence of ampC-carrying plasmids derived from other species was also determined, to exclude these from further analysis. ampC-carrying plasmids were found in 10 of the 50 strains, all of which were of the CIT-type. Analysis of the chromosomal ampC promoter region in the 40 remaining strains showed mutations at 16 different positions, with 18 different genotype patterns detected overall. The most common ampC chromosomal mutation, present in 25 of 40 strains, was a T→A transition at position -32. This mutation has been shown by others to increase enzyme production by up to 46-fold. Altogether, three separate mutations (-32, -42 and -13ins) were present in 90% of the 40 non-plasmid strains, indicating a strong association with the resistance observed. It appears, therefore, that the majority of AmpC-mediated resistance in E. coli can be accounted for by just three point mutations in the chromosome

    Portmanteau tests for linearity of Stationary Time Series

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    This paper considers the problem of testing for linearity of stationary time series. Portmanteau tests are discussed which are based on generalized correlations of residuals from a linear model (that is, autocorrelations and cross-correlations of different powers of the residuals). The finite-sample properties of the tests are assessed by means of Monte Carlo experiments. The tests are applied to 100 time series of stock returns

    Developing global recommendations for action on climate change and mental health across sectors: a Delphi-style study

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    Climate change is causing far-reaching yet underappreciated worsening of outcomes across the mental health and wellbeing spectrum. Despite increasing attention to the mental health impacts of climate change, an absence of a clear, cross-sectoral agenda for action has held back progress against the dual and interconnected challenges of supporting human and planetary health. This study aims to serve as an essential first step to address this gap. Harnessing the expertise of a diverse panel of 61 participants, representing 24 nationalities, this study developed and prioritized recommendations for action on climate change and mental health across the relevant sectors of research, policy, healthcare and the third sector, and used a Delphi-style methodology to examine their feasibility and importance. Broadly, the prioritized recommendations highlighted the need to expand the evidence base, work collaboratively across sectors, and raise awareness. While broadly there was consensus on recommendation importance, there was greater variation in the reported feasibility of the recommendations, which differed across settings. Other common themes included the need for cultural and resource contextualization, raising awareness of and addressing mental health co-benefits via climate action, and working with communities with lived experience to develop and implement the findings. As there may be some interdependencies between the recommendations, further work needs to identify how best to implement them. The recommendations serve as a robust and evidence-based framework that can be used as a foundation to devise locally appropriate, concrete implementation strategies matching levels of need and resource. These also serve as a clear call to action for investment from leaders across sectors to ensure they are realized

    Comparison of the stand-alone Cox-Maze IV procedure to the concomitant Cox-Maze IV and mitral valve procedure for atrial fibrillation

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    BACKGROUND: The majority of patients undergoing surgical ablation for atrial fibrillation (AF) worldwide receive a concomitant mitral valve (MV) procedure. This study compared outcomes of the Cox-Maze IV (CMIV) in patients with lone AF to those with AF and MV disease. METHODS: A retrospective review of 335 patients receiving either a stand-alone CMIV for AF (n=151) or a CMIV with a MV procedure (n=184) was performed from January 2002 through December of 2012. Data were obtained at 3, 6, 12, 24, and 48 months and patients were evaluated for recurrence of AF. Twenty-four preoperative and perioperative variables were evaluated to identify predictors of AF recurrence at one year. RESULTS: The two groups differed in that stand-alone CMIV patients were younger, had AF of longer duration and had more failed catheter ablations, while patients with AF and MV disease had larger left atria and worse New York Heart Association class (P≀0.001). Operative mortality was higher in the concomitant MV group (1% vs. 5%, P=0.015). Freedom from AF and antiarrhythmic drugs at 12 and 24 months were similar between the two groups (73% and 76% at 12 months; 77% vs. 78% at 24 months). Predictors of recurrence included failure to use a box-lesion to isolate the pulmonary veins and posterior left atria, early recurrence of atrial tachyarrhythmias (ATAs) and the presence of a preoperative pacemaker (P=0.001). CONCLUSIONS: The efficacy of the CMIV procedure was similar in patients with and without co-existent MV pathology. Patients receiving a concomitant CMIV and MV procedure represented an older and sicker patient population and had higher mortality rates than those receiving a stand-alone CMIV procedure

    Resource dedication problem in a multi-project environment

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    There can be different approaches to the management of resources within the context of multi-project scheduling problems. In general, approaches to multiproject scheduling problems consider the resources as a pool shared by all projects. On the other hand, when projects are distributed geographically or sharing resources between projects is not preferred, then this resource sharing policy may not be feasible. In such cases, the resources must be dedicated to individual projects throughout the project durations. This multi-project problem environment is defined here as the resource dedication problem (RDP). RDP is defined as the optimal dedication of resource capacities to different projects within the overall limits of the resources and with the objective of minimizing a predetermined objective function. The projects involved are multi-mode resource constrained project scheduling problems with finish to start zero time lag and non-preemptive activities and limited renewable and nonrenewable resources. Here, the characterization of RDP, its mathematical formulation and two different solution methodologies are presented. The first solution approach is a genetic algorithm employing a new improvement move called combinatorial auction for RDP, which is based on preferences of projects for resources. Two different methods for calculating the projects’ preferences based on linear and Lagrangian relaxation are proposed. The second solution approach is a Lagrangian relaxation based heuristic employing subgradient optimization. Numerical studies demonstrate that the proposed approaches are powerful methods for solving this problem

    The risk of telling : a dyadic perspective on romantic partners' responses to child sexual abuse disclosure and their associations with sexual and relationship satisfaction

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    Essai prĂ©sentĂ© Ă  la FacultĂ© des arts et des sciences en vue de l'obtention du grade de Doctorat en psychologie clinique (D. Psy.)Les survivants d’agression sexuelle Ă  l’enfance (ASE) doivent souvent composer avec les consĂ©quences Ă  long terme de ce trauma. Toutefois, il existe une grande variabilitĂ© quant aux impacts individuels de l’ASE. Certains auteurs croient que la rĂ©ponse obtenue lors du dĂ©voilement de l’ASE aux proches du survivant, pourrait ĂȘtre l’un des dĂ©terminants de cette variabilitĂ©. Cependant, le dĂ©voilement Ă  l’ñge adulte, notamment au partenaire amoureux, a Ă©tĂ© peu Ă©tudiĂ©. La prĂ©sente Ă©tude examine les associations entre les rĂ©ponses des partenaires amoureux au dĂ©voilement, tels que perçues par les survivants, ainsi que la satisfaction sexuelle et conjugale des deux membres du couple, auprĂšs d’un Ă©chantillon de 70 couples de la communautĂ© ayant rapportĂ© une ASE et l’ayant dĂ©voilĂ©e Ă  leur partenaire. Les participants ont complĂ©tĂ© des questionnaires auto-rapportĂ©s en ligne. Les rĂ©sultats d’analyses de trajectoire au sein d’un modĂšle « Actor-Partner Interdependence Model » (APIM) indiquent que les rĂ©ponses de « soutien Ă©motionnel » de la part des partenaires durant le dĂ©voilement, telles que perçues par les survivants, Ă©taient positivement associĂ©es Ă  leur propre satisfaction sexuelle ainsi qu’à celle de leur partenaire. Les rĂ©ponses de « stigmatisation/se sentir traitĂ© diffĂ©remment » de la part des partenaires, telles que perçues par les survivants, Ă©taient associĂ©es Ă  une moins bonne satisfaction conjugale, Ă  la fois pour les survivants et leurs partenaires. Les rĂ©sultats suggĂšrent que les rĂ©ponses des partenaires au dĂ©voilement d’une ASE, tels que perçues par les survivants, peuvent avoir un impact positif autant que nĂ©gatif sur la satisfaction conjugale et sexuelle des deux partenaires.Survivors of childhood sexual abuse (CSA) often experience adverse trauma-related long term consequences, which vary widely among survivors. Some authors argued that this variability might be explained in part by the response of others to survivors’ disclosure of the CSA. However, disclosure during adulthood has received little empirical attention, in particular, disclosure to a romantic partner. Among 70 community couples who reported CSA and disclosure to their partner, this study examined associations between survivors’ perception of partner responses to their disclosure, and both partners’ sexual and relationship satisfaction. Participants completed self-report questionnaires online. Results of path analyses within an actor-partner interdependence model indicated that survivors’ perceived partner responses of emotional support to disclosure were associated with their own and their partners' higher sexual satisfaction. Survivors’ perceived responses of being stigmatized/treated differently by the partner were associated with their own and their partners’ poorer relationship satisfaction. Findings suggest that survivor-perceived partner responses to the disclosure of CSA can have both a positive and a negative impact on the sexual and relationship satisfaction of both partners
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