Impaired Hyperemic Response to Exercise Post Stroke

Individuals with chronic stroke have reduced perfusion of the paretic lower limb at rest; however, the hyperemic response to graded muscle contractions in this patient population has not been examined. This study quantified blood flow to the paretic and non-paretic lower limbs of subjects with chronic stroke after submaximal contractions of the knee extensor muscles and correlated those measures with limb function and activity. Ten subjects with chronic stroke and ten controls had blood flow through the superficial femoral artery quantified with ultrasonography before and immediately after 10 second contractions of the knee extensor muscles at 20, 40, 60, and 80% of the maximal voluntary contraction (MVC) of the test limb. Blood flow to the paretic and non-paretic limb of stroke subjects was significantly reduced at all load levels compared to control subjects even after normalization to lean muscle mass. Of variables measured, increased blood flow after an 80% MVC was the single best predictor of paretic limb strength, the symmetry of strength between the paretic and non-paretic limbs, coordination of the paretic limb, and physical activity. The impaired hemodynamic response to high intensity contractions was a better predictor of lower limb function than resting perfusion measures. Stroke-dependent weakness and atrophy of the paretic limb do not explain the reduced hyperemic response to muscle contraction alone as the response is similarly reduced in the non-paretic limb when compared to controls. These data may suggest a role for perfusion therapies to optimize rehabilitation post stroke

Searching speeds and the energetic feasibility of an obligate whale-scavenging fish

Two recently published models reach opposite conclusions on the energetic feasibility of a scavenging fish that specialises oil whale carcasses. We argue that the key difference between these models lies in their estimate of the likely searching speed of such a hypothetical scavenger. Neither of the previous models considers that although faster searching will allow food sites to be found more quickly, it will also reduce the time between meals that the fish can survive on its reserves. Hence, we present a novel model that encapsulates this trade-off, and use this model to predict the optimal searching speed for Such a hypothetical scavenger. The model predicts that the optimal speed should increase with mass and be in the range 0.1-0.2 m s(-1) for fish of the range of sizes found for the ubiquitous grenadier Coryphaenoides armatus. These values accord with most estimates of the swimming speeds for this species. Hence, we conclude that rejection of a whale-carcass feeding specialist fish on energetic grounds is premature. Although, we see no reason to dismiss Such a specialist oil energetic grounds, we argue that such a fish will be unlikely oil ecological grounds, although a deep-sea fish that gathered much of its energy from scavenging at relatively large food packages oil the ocean floor should be feasible

Stabilizing the surface morphology of Si1–x–yGexCy/Si heterostructures grown by molecular beam epitaxy through the use of a silicon-carbide source

Si1–x–yGexCy/Si superlattices were grown by solid-source molecular beam epitaxy using silicon carbide as a source of C. Samples consisting of alternating layers of nominally 25 nm Si1–x–yGexCy and 35 nm Si for 10 periods were characterized by high-resolution x-ray diffraction, transmission electron microscopy (TEM), and Rutherford backscattering spectrometry to determine strain, thickness, and composition. C resonance backscattering and secondary ion mass spectrometries were used to measure the total C concentration in the Si1–x–yGexCy layers, allowing for an accurate determination of the substitutional C fraction to be made as a function of growth rate for fixed Ge and substitutional C compositions. For C concentrations close to 1%, high-quality layers were obtained without the use of Sb-surfactant mediation. These samples were found to be structurally perfect to a level consistent with cross-sectional TEM (< 10^7 defects/cm^2) and showed considerably improved homogeneity as compared with similar structures grown using graphite as the source for C. For higher Ge and C concentrations, Sb-surfactant mediation was found to be required to stabilize the surface morphology. The maximum value of substitutional C concentration, above which excessive generation of stacking fault defects caused polycrystalline and/or amorphous growth, was found to be approximately 2.4% in samples containing between 25 and 30% Ge. The fraction of substitutional C was found to decrease from roughly 60% by a factor of 0.86 as the Si1–x–yGexCy growth rate increased from 0.1 to 1.0 nm/s

Effective zero-thickness model for a conductive membrane driven by an electric field

The behavior of a conductive membrane in a static (DC) electric field is investigated theoretically. An effective zero-thickness model is constructed based on a Robin-type boundary condition for the electric potential at the membrane, originally developed for electrochemical systems. Within such a framework, corrections to the elastic moduli of the membrane are obtained, which arise from charge accumulation in the Debye layers due to capacitive effects and electric currents through the membrane and can lead to an undulation instability of the membrane. The fluid flow surrounding the membrane is also calculated, which clarifies issues regarding these flows sharing many similarities with flows produced by induced charge electro-osmosis (ICEO). Non-equilibrium steady states of the membrane and of the fluid can be effectively described by this method. It is both simpler, due to the zero thickness approximation which is widely used in the literature on fluid membranes, and more general than previous approaches. The predictions of this model are compared to recent experiments on supported membranes in an electric field.Comment: 14 pages, 5 figure

Can Red Clay Go Green? Adapting Law and Policy in the Face of Climate Change, 20th Annual Red Clay Conference

Program for the 20th Annual Red Clay Conference held Friday, April 4, 2008 at the University of Georgia School of Law\u27s Dean Rusk Hall

Generalized Lévy walks and the role of chemokines in migration of effector CD8+ T cells.

Chemokines have a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. Here we track T cells using multi-photon microscopy to demonstrate that the chemokine CXCL10 enhances the ability of CD8+ T cells to control the pathogen Toxoplasma gondii in the brains of chronically infected mice. This chemokine boosts T-cell function in two different ways: it maintains the effector T-cell population in the brain and speeds up the average migration speed without changing the nature of the walk statistics. Notably, these statistics are not Brownian; rather, CD8+ T-cell motility in the brain is well described by a generalized Lévy walk. According to our model, this unexpected feature enables T cells to find rare targets with more than an order of magnitude more efficiency than Brownian random walkers. Thus, CD8+ T-cell behaviour is similar to Lévy strategies reported in organisms ranging from mussels to marine predators and monkeys, and CXCL10 aids T cells in shortening the average time taken to find rare targets

Scotland Registry for Ankylosing Spondylitis (SIRAS) – Protocol

Funding SIRAS was funded by unrestricted grants from Pfizer and AbbVie. The project was reviewed by both companies, during the award process, for Scientific merit, to ensure that the design did not compromise patient safety, and to assess the global regulatory implications and any impact on regulatory strategy.Publisher PD

A Student\u27s Perspective on the Utilization of Social Media for Scholarly Research

The research was conducted on the continuous advancements on the Airline Quality Rating (AQR) developed by Dr . Brent Bowen, and the benefactor of research from a student perspective . The general case study focus of this research is the AQR as it relates to the utilization of social media platforms, and thus having the ability to reach out to a broader worldwide presence . Media metrics consisting of social network platforms, and news releases to assist in broadening the viewership and utilization of research in meeting individuals needs in gaining qualitative and quantified information about the AQR . As a student researcher for the AQR research initiative, it has helped me grow exponentially through the utilization of applied research methods . Additionally, while writing towards a potential audience, it has enhanced my communication skills through the presentations to members of the conferences in which I have attended

Precipitation and Not Cover Crop Composition Influenced Corn Economic Optimal N Rate and Yield

The effects of single species cover crops on corn (Zea mays L.) N requirement and grain yield are well studied throughout the U.S. Midwest. However, comparing cover crop mixes that include different compositions of grass and broadleaf species is limited. Fourteen corn N response experiments were conducted in South Dakota from 2018 to 2021. Fall cover crops planted after small grain harvest were mixtures of dominantly grasses, broadleaves, a 50/50 grass/broadleaf mixture, and a no cover crop control. Compared to the control, including a cover crop led to no differences in economic optimal N rate (EONR) and yield at zero N (0N) and yield at EONR 44%, 62%, and 83% of the time, respectively. As spring cover crop/residue biomass and its C and N content increased, corn yield at EONR decreased and EONR increased when including cover crops (R2 = 0.36–0.56). Including cover crops reduced EONR and resulted in a similar yield when precipitation increased above 850 mm. When differences occurred with economic return from N, including a cover crop reduced economic return in 3 site-years (mean decrease of US$358 ha−1) and in only 1 site-year did including a grass cover crop increase economic return from N (+US$335 ha−1). Thus, in the first year of growing cover crops (i.e., grasses, broadleaves, or a grass/broadleaf mix) before corn, growers can normally expect some differences in EONR. However, with the appropriate rate of N, yield at EONR is maintained and any economic differences from N normally minimized

The Future of Social Media Usage for Scholarly Research

The research method for this project – examining the dissemination of research artifacts through social media as well as the impact social media can have on scholarly research – originated with Dr. Brent Bowen of Embry-Riddle Aeronautical University at the Prescott, Arizona campus and Dr. Dean E. Headley of Wichita State University. Drs. Bowen and Headley introduced the Airline Quality Rating (AQR) in early 1991 as an objective method for comparing and scoring airline performance in areas deemed to be important for consumers. Scores are calculated by defining 15-elements in four major areas, focusing on airline performance and the significance the factors to consumers of air travel in a given calendar year. The report is a summary and evaluation of month-by-month ratings for U.S. airlines, based on domestic performance data which these companies are required to publish. The general case study focus of this research is the AQR as it relates to the news of the AQR’s release as disseminated through social media platforms, the subsequent utilization of and references to the research by social media users, and the global reach of social media. We will examine social media metrics, based on traditional news releases. These news releases, when amplified by social media platforms, assist in broadening the viewership and the utilization of research. The AQR’s Visibility Reports evaluate four aspects of online traffic - Total Pickup, Traffic flow, Audience, and Engagement. We will discuss how the Airline Quality Rating has helped to facilitate a worldwide discussion on U.S. airlines and domestic air travel within the U.S