1,093 research outputs found
Mechanical Demands of the Hang Power Clean and Jump Shrug: A Joint-level Perspective
The purpose of this study was to investigate the joint- and load-dependent changes in the mechanical demands of the lower extremity joints during the hang power clean (HPC) and the jump shrug (JS). Fifteen male lacrosse players were recruited from an NCAA DI team, and completed three sets of the HPC and JS at 30%, 50%, and 70% of their HPC 1-Repetition Maximum (1-RM HPC) in a counterbalanced and randomized order. Motion analysis and force plate technology were used to calculate the positive work, propulsive phase duration, and peak concentric power at the hip, knee, and ankle joints. Separate three-way analysis of variances were used to determine the interaction and main effects of joint, load, and lift type on the three dependent variables. The results indicated that the mechanics during the HPC and JS exhibit joint-, load-, and lift-dependent behavior. When averaged across joints, the positive work during both lifts increased progressively with external load, but was greater during the JS at 30% and 50% of 1-RM HPC than during the HPC. The JS was also characterized by greater hip and knee work when averaged across loads. The joint-averaged propulsive phase duration was lower at 30% than at 50% and 70% of 1-RM HPC for both lifts. Furthermore, the load-averaged propulsive phase duration was greater for the hip than the knee and ankle joint. The jointaveraged peak concentric power was the greatest at 70% of 1-RM for the HPC and at 30% to 50% of 1-RM for the JS. In addition, the joint-averaged peak concentric power of the JS was greater than that of the HPC. Furthermore, the load-averaged peak knee and ankle concentric joint powers were greater during the execution of the JS than the HPC. However, the loadaveraged power of all joints differed only during the HPC, but was similar between the hip and knee joints for the JS. Collectively, these results indicate that compared to the HPC the JS is characterized by greater hip and knee positive joint work, and greater knee and ankle peak concentric joint power, especially if performed at 30 and 50% of 1-RM HPC. This study provides important novel information about the mechanical demands of two commonly used exercises and should be considered in the design of resistance training programs that aim to improve the explosiveness of the lower extremity joints
First Passage Times for Continuous Quantum Measurement Currents
The First Passage Time (FPT) is the time taken for a stochastic process to
reach a desired threshold. It finds wide application in various fields and has
recently become particularly important in stochastic thermodynamics, due to its
relation to kinetic uncertainty relations (KURs). In this letter we address the
FPT of the stochastic measurement current in the case of continuously measured
quantum systems. Our approach is based on a charge-resolved master equation,
which is related to the Full-Counting statistics of charge detection. In the
quantum jump unravelling we show that this takes the form of a coupled system
of master equations, while for quantum diffusion it becomes a type of quantum
Fokker-Planck equation. In both cases, we show that the FPT can be obtained by
introducing absorbing boundary conditions, making their computation extremely
efficient. The versatility of our framework is demonstrated with two relevant
examples. First, we show how our method can be used to study the tightness of
recently proposed KURs for quantum jumps. Second, we study the homodyne
detection of a single two-level atom, and show how our approach can unveil
various non-trivial features in the FPT distribution.Comment: 8 pages, 2 figure
Inflammatory gene expression profiles in sporadic, familial and TREM2 variant Alzheimer's disease
Atomistic Studies of Defect Nucleation during Nanoindentation of Au (001)
Atomistic studies are carried out to investigate the formation and evolution
of defects during nanoindentation of a gold crystal. The results in this
theoretical study complement the experimental investigations [J. D. Kiely and
J. E. Houston, Phys. Rev. B, v57, 12588 (1998)] extremely well. The defects are
produced by a three step mechanism involving nucleation, glide and reaction of
Shockley partials on the {111} slip planes noncoplanar with the indented
surface. We have observed that slip is in the directions along which the
resolved shear stress has reached the critical value of approximately 2 GPa.
The first yield occurs when the shear stresses reach this critical value on all
the {111} planes involved in the formation of the defect. The phenomenon of
strain hardening is observed due to the sessile stair-rods produced by the
zipping of the partials. The dislocation locks produced during the second yield
give rise to permanent deformation after retraction.Comment: 11 pages, 13 figures, submitted to Physical Review
Perspectives on Transitioning Uninsured Persons from an Emergency Department to Federally Qualified Health Centers in East Baltimore
Many people in the United States rely on the emergency department (ED) for their usual source of primary care. Linking these ED users to a source of longitudinal primary care could provide significant health benefits. To assess an intervention attempting to connect ED users to federally qualified health cents (FQHCs), we conducted semi-structured, in-depth interviews with volunteers, health facility providers, and a patient and a focus group with program volunteers. All sessions were digitally recorded, transcribed and analyzed to develop emergent themes highlighting the barriers and facilitating factors that affect the process of connecting patients to primary care. Themes included that 1) the ED is the preferred source of primary care over FQHCs, 2) there are limited links between EDs and FQHCs and 3) the evaluated intervention acts through and depends on patients’ prioritization of health and access to resources. Our findings suggest that, in addition to addressing individual needs, social services programs are well positioned to help increase communication between providers at FQHCs and EDs about both the services available to patients and patients’ medical care histories
Adam Smith and Colonialism
In the context of debates about liberalism and colonialism, the arguments of Adam Smith have been taken as illustrative of an important line of anti-colonial liberal thought. The reading of Smith presented here challenges this interpretation. It argues that Smith’s opposition to colonial rule derived largely from its impact on the metropole, rather than on its impact on the conquered and colonised; that Smith recognised colonialism had brought ‘improvement’ in conquered territories and that Smith struggled to balance recognition of moral diversity with a universal moral framework and a commitment to a particular interpretation of progress through history. These arguments have a wider significance as they point towards some of the issues at stake in liberal anti-colonial arguments more generally
Neuropathological features of genetically confirmed DYT1 dystonia: investigating disease-specific inclusions.
IntroductionEarly onset isolated dystonia (DYT1) is linked to a three base pair deletion (¿GAG) mutation in the TOR1A gene. Clinical manifestation includes intermittent muscle contraction leading to twisting movements or abnormal postures. Neuropathological studies on DYT1 cases are limited, most showing no significant abnormalities. In one study, brainstem intraneuronal inclusions immunoreactive for ubiquitin, torsinA and lamin A/C were described. Using the largest series reported to date comprising 7 DYT1 cases, we aimed to identify consistent neuropathological features in the disease and determine whether we would find the same intraneuronal inclusions as previously reported.ResultThe pathological changes of brainstem inclusions reported in DYT1 dystonia were not replicated in our case series. Other anatomical regions implicated in dystonia showed no disease-specific pathological intracellular inclusions or evidence of more than mild neuronal loss.ConclusionOur findings suggest that the intracellular inclusions described previously in DYT1 dystonia may not be a hallmark feature of the disorder. In isolated dystonia, DYT1 in particular, biochemical changes may be more relevant than the morphological changes
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Food fortification and biofortification as potential strategies for prevention of vitamin D deficiency
Hypovitaminosis D (vitamin D deficiency) is widespread throughout the world.
The cutaneous production of vitamin D through sunlight can be limited by
several factors (e.g. skin pigmentation, sunscreen usage and, increasingly, indoor
lifestyle). Thus, diet has become an important strategy to increase vitamin D
intake and status {blood 25-hydroxyvitamin D [25(OH)D]}. However, there are a
limited number of foods that naturally contain vitamin D, and concentrations
can vary significantly between and within species. The need for vitamin Dfortified
foods (including via direct fortification and biofortification) to support
the adequacy of vitamin D status is a corollary of several limitations to
synthesise vitamin D from sunlight. Ergocalciferol (vitamin D2) and
cholecalciferol (vitamin D3) can be found in some mushrooms and animalderived
foods, respectively. Evidence has shown vitamin D3 is more effective than
vitamin D2 at raising 25(OH)D blood concentrations. The vitamin D metabolite,
25(OH)D3, is present in animal-derived foods (e.g. meat, eggs and fish), and
several intervention trials have shown 25(OH)D3 to be more effective at raising
blood 25(OH)D concentrations than vitamin D3. In addition, 25(OH)D3
supplements may prove to be preferable to vitamin D3 for patients with certain
clinical conditions. However, there is limited evidence on the effects of 25(OH)
D3-fortified foods on human vitamin D status and health, both in the general
population and patients with certain conditions, and long-term randomised
controlled trials are needed in this area
17 ways to say yes:Toward nuanced tone of voice in AAC and speech technology
People with complex communication needs who use speech-generating devices have very little expressive control over their tone of voice. Despite its importance in human interaction, the issue of tone of voice remains all but absent from AAC research and development however. In this paper, we describe three interdisciplinary projects, past, present and future: The critical design collection Six Speaking Chairs has provoked deeper discussion and inspired a social model of tone of voice; the speculative concept Speech Hedge illustrates challenges and opportunities in designing more expressive user interfaces; the pilot project Tonetable could enable participatory research and seed a research network around tone of voice. We speculate that more radical interactions might expand frontiers of AAC and disrupt speech technology as a whole
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