Results suggest that the survival rate for cats requiring PPV may be lower than reported survival rates for dogs. Death was attributable to progressive respiratory failure, non-responsive hypotension, kidney failure, or neurologic impairment.

This report describes the clinical, histopathologic, and imaging findings of multifocal oligodendrogliomas from three canine patients. Clinical history varied but included seizure activity and behavior changes. Neurologic examination abnormalities included ataxia, proprioceptive deficits, cranial nerve deficits, and changes in mentation. MRI in one patient revealed multifocal brain lesions; however, the MRI was normal in another one of the patients. Histopathologic evaluation identified multifocal neoplastic infiltrates in all three patients involving the cerebral cortex, brainstem, and spinal cord, with leptomeningeal extension in two of the three patients. All three patients were euthanized due to progression of their neurologic condition and/or complications due to aspiration pneumonia. Oligodendrogliomas should be considered a differential diagnosis for patients with multifocal brain disease.

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The numerical simulation of many-particle systems (e.g., in molecular dynamics) often involves constraints of various forms. We present a symplectic integrator for mechanical systems with holonomic (bilateral) and unilateral contact constraints, the latter being in the form of a nonpenetration condition. The scheme is based on a discrete variant of Hamilton's principle in which both the discrete trajectory and the unknown collision time are varied (cf. [Fetecau et al., 2003, SIAM J. Applied Dynamical Systems, 2, pp. 381-416]). As a consequence, the collision event enters the discrete equations of motion as an unknown that has to be computed on-the-fly whenever a collision is imminent. The additional bilateral constraints are e ciently dealt with employing a discrete null space reduction (including a projection and a local reparametrisation step) which considerably reduces the number of unknowns and improves the condition number during each time-step as compared to a standard treatment with Lagrange multipliers. We illustrate the numerical scheme with a simple example from polymer dynamics, a linear chain of beads, and test it against other standard numerical schemes for collision problems.

The present study conducted a meta-analysis to examine the relation between grit and subjective well-being (SWB). The association between grit (i.e., overall grit, perseverance of effort, and consistency of interest) and SWB (i.e., positive affect, negative affect, happiness, depression, life satisfaction, job satisfaction, and school satisfaction) were synthesized across 83 studies and 66,518 participants. The results based on a random-effects model showed a substantial correlation between overall grit and SWB (ρ = .46, 95% confidence interval [CI] = [.43, .48]), followed by perseverance of effort (ρ = .38, 95% CI = [.33, .43]) and consistency of interest (ρ = .23, 95% CI = [.17, .28]). The moderator analysis indicated that the correlations between overall grit/consistency of effort and SWB become weaker as age increased, and these links were stronger in affective well-being than in cognitive well-being. Moreover, grit explained unique variance in SWB even after controlling for conscientiousness. Implications and directions for further research are discussed.

Abstract. Due to their high item difficulties and excellent psychometric properties, construction-based figural matrices tasks are of particular interest when it comes to high-stakes testing. An important prerequisite is that test preparation – which is likely to occur in this context – does not impair test fairness or item properties. The goal of this study was to provide initial evidence concerning the influence of test preparation. We administered test items to a sample of N = 882 participants divided into two groups, but only one group was given information about the rules employed in the test items. The probability of solving the items was significantly higher in the test preparation group than in the control group ( M = 0.61, SD = 0.19 vs. M = 0.41, SD = 0.25; t(54) = 3.42, p = .001; d = .92). Nevertheless, a multigroup confirmatory factor analysis, as well as a differential item functioning analysis, indicated no differences between the item properties in the two groups. The results suggest that construction-based figural matrices are suitable in the context of high-stakes testing when all participants are provided with test preparation material so that test fairness is ensured.

In this work, we optimally control the upright gait of a three-dimensional symmetric bipedal walking model with flat feet. The whole walking cycle is assumed to occur during a fixed time span while the time span for each of the cycle phases is variable and part of the optimization. The implemented flat foot model allows to distinguish forefoot and heel contact such that a half walking cycle consists of five different phases. A fixed number of discrete time nodes in combination with a variable time interval length assure that the discretized problem is differentiable even though the particular time of establishing or releasing the contact between the foot and the ground is variable. Moreover, the perfectly plastic contact model prevents penetration of the ground. The optimal control problem is solved by our structure preserving discrete mechanics and optimal control for constrained systems (DMOCC) approach where the considered cost function is physiologically motivated and the obtained results are analyzed with regard to the gait of humans walking on a horizontal and an inclined plane.

This work considers the optimal control of multibody systems being actuated with control forces which impact the system's motion directly. The goal is to find a dynamically feasible trajectory of states and control leading from an initial to a desired final state, while minimising an objective function. The optimal control problem is solved using a direct transcription method, i.e. boundary conditions and a discrete version of the equations of motion serve as constraints for the minimisation of a cost function with respect to the discrete state and control trajectory. Here, a particular time stepping scheme, an energy momentum integrator based on discrete derivatives is used. Corresponding to a constrained formulation of multibody systems, we develop an energy momentum consistent discrete force formulation that fits into the energy momentum integrator.