38,909 research outputs found

    Computed tomography and magnetic resonance diagnosis of variations in the anatomical location of the major salivary glands in 1680 dogs and 187 cats

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    During assessment of routine clinical magnetic resonance imaging (MRI) of the heads of dogs, variations in the location of mandibular and zygomatic salivary glands (SGs) were observed incidentally. The aims of this retrospective study were to describe anatomical variations of the major SGs found on MRI and computed tomography (CT) studies of the head in dogs and cats and to investigate possible clinical relevancy. No anatomical variation of the SGs was seen in cats, but in dogs, although variation of the parotid SG was not identified, that of the mandibular SG was found in 33/1680 animals (2%), either unilaterally (6/33 right-sided, 13/33 left-sided) or bilaterally (14/33). The Border terrier breed (19/33, 58%) was over-represented. Each atypically located mandibular SG was positioned medial to the digastric muscle and rostral to the retropharyngeal lymph node. The sublingual glands were difficult to delineate from the mandibular glands. Anatomical variation of one zygomatic gland (3/4 left-sided) was identified in four small-breed dogs (0.2%). Each atypically located zygomatic gland was tilted at the ventrorostral aspect of the masseter muscle underneath the skin surface. MRI and CT characteristics were not different between typically and atypically located SGs. None of the dogs had clinical signs related with SG disease. It was concluded that, with suspected breed predispositions, incidental unilateral or bilateral anatomical variations of mandibular and zygomatic SGs can be encountered in dogs and an awareness of these possible variations may be important in pre-surgical planning

    Beyond the RCT: Integrating Rigor and Relevance to Evaluate the Outcomes of Domestic Violence Programs

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    Programs for domestic violence (DV) victims and their families have grown exponentially over the last four decades. The evidence demonstrating the extent of their effectiveness, however, often has been criticized as stemming from studies lacking scientific rigor. A core reason for this critique is the widespread belief that credible evidence can derive only from research grounded in randomized control trials (RCTs). Although the RCT method has its strengths, we argue that it is rarely an optimal—or even a possible—approach for evaluating multifaceted DV programs. This article reviews the reasons that RCT is a poor fit for such programs and argues that a more inclusive conceptualization of credible evidence is critical to expanding our knowledge base about how DV programs affect survivors’ safety and well-being

    Elastic, Viscous, and Mass Load Effects on Poststroke Muscle Recruitment and Co-contraction During Reaching: A Pilot Study

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    Background: Resistive exercise after stroke can improve strength (force-generating capacity) without increasing spasticity (velocity-dependent hypertonicity). However, the effect of resistive load type on muscle activation and co-contraction after stroke is not clear. Objective: The purpose of this study was to determine the effect of load type (elastic, viscous, or mass) on muscle activation and co-contraction during resisted forward reaching in the paretic and nonparetic arms after stroke. Design: This investigation was a single-session, mixed repeated-measures pilot study. Methods: Twenty participants (10 with hemiplegia and 10 without neurologic involvement) reached forward with each arm against equivalent elastic, viscous, and mass loads. Normalized shoulder and elbow electromyography impulses were analyzed to determine agonist muscle recruitment and agonist-antagonist muscle co-contraction. Results: Muscle activation and co-contraction levels were significantly higher on virtually all outcome measures for the paretic and nonparetic arms of the participants with stroke than for the matched control participants. Only the nonparetic shoulder responded to load type with similar activation levels but variable co-contraction responses relative to those of the control shoulder. Elastic and viscous loads were associated with strong activation; mass and viscous loads were associated with minimal co-contraction. Limitations: A reasonable, but limited, range of loads was available. Conclusions: Motor control deficits were evident in both the paretic and the nonparetic arms after stroke when forward reaching was resisted with viscous, elastic, or mass loads. The paretic arm responded with higher muscle activation and co-contraction levels across all load conditions than the matched control arm. Smaller increases in muscle activation and co-contraction levels that varied with load type were observed in the nonparetic arm. On the basis of the response of the nonparetic arm, this study provides preliminary evidence suggesting that viscous loads elicited strong muscle activation with minimal co-contraction. Further intervention studies are needed to determine whether viscous loads are preferable for poststroke resistive exercise programs

    Self-contained breathing apparatus

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    A self-contained breathing apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level

    Strong convergence rates of probabilistic integrators for ordinary differential equations

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    Probabilistic integration of a continuous dynamical system is a way of systematically introducing model error, at scales no larger than errors introduced by standard numerical discretisation, in order to enable thorough exploration of possible responses of the system to inputs. It is thus a potentially useful approach in a number of applications such as forward uncertainty quantification, inverse problems, and data assimilation. We extend the convergence analysis of probabilistic integrators for deterministic ordinary differential equations, as proposed by Conrad et al.\ (\textit{Stat.\ Comput.}, 2017), to establish mean-square convergence in the uniform norm on discrete- or continuous-time solutions under relaxed regularity assumptions on the driving vector fields and their induced flows. Specifically, we show that randomised high-order integrators for globally Lipschitz flows and randomised Euler integrators for dissipative vector fields with polynomially-bounded local Lipschitz constants all have the same mean-square convergence rate as their deterministic counterparts, provided that the variance of the integration noise is not of higher order than the corresponding deterministic integrator. These and similar results are proven for probabilistic integrators where the random perturbations may be state-dependent, non-Gaussian, or non-centred random variables.Comment: 25 page

    Standard model explanation of a CDF dijet excess in Wjj

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    We demonstrate the recent observation of a peak in the dijet invariant mass of the Wjj signal observed by the CDF Collaboration can be explained as the same upward fluctuation observed by CDF in single-top-quark production. In general, both t-channel and s-channel single-top-quark production produce kinematically induced peaks in the dijet spectrum. Since CDF used a Monte Carlo simulation to subtract the single-top backgrounds instead of data, a peak in the dijet spectrum is expected. The D0 Collaboration has a small upward fluctuation in their published t-channel data; and hence we predict they would see at most a small peak in the dijet invariant mass spectrum of Wjj if they follow the same procedure as CDF.Comment: 3 pg., 2 figs, revtex, minor clarifications, to appear in Phys. Rev.
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