193 research outputs found

    An Investigation of Wing-Body Junction Flows

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    Junction flows are a phenomenon frequently encountered in a variety of fields with a diversity of applications. Junction flows, with its individual components, is a complex, coupled, and interacting flow field. While there exists some understanding of its individual component such as the horseshoe vortices and corner separations present in these flows, there is very little predictive understanding of the entire interacting flow mechanism which is the focus of this research. Utilizing a NACA 2415 wing section in tandem with various flow visualization techniques, it was discovered that the horseshoe vortex is invariant in its presence, while the corner separation was highly dependent on the angle of attack and placement of the wing section in the flow. The sizing of both depended primarily on the angle of attack of the wing. Further research should focus on corroborating these results, correct inconsistencies in flow visualization seeding, possible misidentification of the flow mechanisms and vary the flow field condition

    Chronic Daily Headache in Children and Adolescents: A Multi-Faceted Syndrome

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    AbstractChronic daily headache (CDH) is a multi-faceted, often complex pain syndrome in children and adolescents. Chronic daily headache may be primary or secondary. Chronic migraine and chronic tension-type are the most frequent subtypes. Chronic daily headache is co-morbid with adverse life events, anxiety and depressive disorders, possibly with other psychiatric disorders, other pain syndromes and sleep disorders; these conditions contribute to initiating and maintaining CDH. Hence, early management of episodic headache and treatment of associated conditions are crucial to prevention. There is evidence for the benefit of psychological therapies, principally relaxation and cognitive behavioral, and promising information on acupuncture for CDH. Data on drug treatment are based primarily on open label studies. The controversies surrounding CDH are discussed and proposals for improvement presented. The multifaceted nature of CDH makes it a good candidate for a multi-axial classification system. Such an approach should facilitate biopsychosocial management and enhance consistency in clinical research

    Non-statistical intermolecular energy transfer from vibrationally excited benzene in a mixed nitrogen-benzene bath.

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    A chemical dynamics simulation was performed to model experiments [N. A. West et al., J. Chem. Phys. 145, 014308 (2016)] in which benzene molecules are vibrationally excited to 148.1 kcal/mol within a N2-benzene bath. A significant fraction of the benzene molecules are excited, resulting in heating of the bath, which is accurately represented by the simulation. The interesting finding from the simulations is the non-statistical collisional energy transfer from the vibrationally excited benzene C6H6 * molecules to the bath. The simulations find that at ∼10-7 s and 1 atm pressure there are four different final temperatures for C6H6 * and the bath. N2 vibration is not excited and remains at the original bath temperature of 300 K. Rotation and translation degrees of freedom of both N2 and C6H6 in the bath are excited to a final temperature of ∼340 K. Energy transfer from the excited C6H6 * molecules is more efficient to vibration of the C6H6 bath than its rotation and translation degrees of freedom, and the final vibrational temperature of the C6H6 bath is ∼453 K, if the average energy of each C6H6 vibration mode is assumed to be RT. There is no vibrational equilibration between C6H6 * and the C6H6 bath molecules. When the simulations are terminated, the vibrational temperatures of the C6H6 * and C6H6 bath molecules are ∼537 K and ∼453 K, respectively. An important question is the time scale for complete energy equilibration of the C6H6 * and N2 and C6H6 bath system. At 1 atm and 300 K, the experimental V-T (vibration-translation) relaxation time for N2 is ∼10-4 s. The simulation time was too short for equilibrium to be attained, and the time for complete equilibration of C6H6 * vibration with translation, rotation, and vibration of the bath was not determined

    Infrastructural Speculations: Tactics for Designing and Interrogating Lifeworlds

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    This paper introduces “infrastructural speculations,” an orientation toward speculative design that considers the complex and long-lived relationships of technologies with broader systems, beyond moments of immediate invention and design. As modes of speculation are increasingly used to interrogate questions of broad societal concern, it is pertinent to develop an orientation that foregrounds the “lifeworld” of artifacts—the social, perceptual, and political environment in which they exist. While speculative designs often imply a lifeworld, infrastructural speculations place lifeworlds at the center of design concern, calling attention to the cultural, regulatory, environmental, and repair conditions that enable and surround particular future visions. By articulating connections and affinities between speculative design and infrastructure studies research, we contribute a set of design tactics for producing infrastructural speculations. These tactics help design researchers interrogate the complex and ongoing entanglements among technologies, institutions, practices, and systems of power when gauging the stakes of alternate lifeworlds

    Recombinant pro-CTSD (cathepsin D) enhances SNCA/α-Synuclein degradation in α-Synucleinopathy models

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    Parkinson disease (PD) is a neurodegenerative disorder characterized by the abnormal intracellular accumulation of SNCA/α-synuclein. While the exact mechanisms underlying SNCA pathology are not fully understood, increasing evidence suggests the involvement of autophagic as well as lysosomal deficiencies. Because CTSD (cathepsin D) has been proposed to be the major lysosomal protease involved in SNCA degradation, its deficiency has been linked to the presence of insoluble SNCA conformers in the brain of mice and humans as well as to the transcellular transmission of SNCA aggregates. We here postulate that SNCA degradation can be enhanced by the application of the recombinant human proform of CTSD (rHsCTSD). Our results reveal that rHsCTSD is efficiently endocytosed by neuronal cells, correctly targeted to lysosomes and matured to an enzymatically active protease. In dopaminergic neurons derived from induced pluripotent stem cells (iPSC) of PD patients harboring the A53T mutation within the SNCA gene, we confirm the reduction of insoluble SNCA after treatment with rHsCTSD. Moreover, we demonstrate a decrease of pathological SNCA conformers in the brain and within primary neurons of a CTSD-deficient mouse model after dosing with rHsCTSD. Boosting lysosomal CTSD activity not only enhanced SNCA clearance, but also restored endo-lysosome and autophagy function in human and murine neurons as well as tissue. Our findings indicate that CTSD is critical for SNCA clearance and function. Thus, enzyme replacement strategies utilizing CTSD may also be of therapeutic interest for the treatment of PD and other synucleinopathies aiming to decrease the SNCA burden.authorsversionepub_ahead_of_prin

    Parkinson’s disease mouse models in translational research

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    Animal models with high predictive power are a prerequisite for translational research. The closer the similarity of a model to Parkinson’s disease (PD), the higher is the predictive value for clinical trials. An ideal PD model should present behavioral signs and pathology that resemble the human disease. The increasing understanding of PD stratification and etiology, however, complicates the choice of adequate animal models for preclinical studies. An ultimate mouse model, relevant to address all PD-related questions, is yet to be developed. However, many of the existing models are useful in answering specific questions. An appropriate model should be chosen after considering both the context of the research and the model properties. This review addresses the validity, strengths, and limitations of current PD mouse models for translational research

    On the interpretation of removable interactions: A survey of the field 33 years after Loftus

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    In a classic 1978 Memory &Cognition article, Geoff Loftus explained why noncrossover interactions are removable. These removable interactions are tied to the scale of measurement for the dependent variable and therefore do not allow unambiguous conclusions about latent psychological processes. In the present article, we present concrete examples of how this insight helps prevent experimental psychologists from drawing incorrect conclusions about the effects of forgetting and aging. In addition, we extend the Loftus classification scheme for interactions to include those on the cusp between removable and nonremovable. Finally, we use various methods (i.e., a study of citation histories, a questionnaire for psychology students and faculty members, an analysis of statistical textbooks, and a review of articles published in the 2008 issue of Psychology andAging) to show that experimental psychologists have remained generally unaware of the concept of removable interactions. We conclude that there is more to interactions in a 2 × 2 design than meets the eye
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