939 research outputs found
Effect of Scoring and Termination Rules on Test–Retest Variability of a Novel High-Pass Letter Acuity Chart
Reliability of Peak Treadmill Exercise Tests in Mild Alzheimer Disease
This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Neuroscience on August 2011, available online: http://www.tandfonline.com/10.3109/00207454.2011.574762.The prevalence of Alzheimer disease (AD) doubles every 5 years after the age of 65, reaching nearly 50% after age 85 (Evans et al., 1989). This, along with an unprecedented growth in the elderly population, is leading to dramatic increases in the incidence of AD. Thus, effective strategies for promoting healthy brain aging and preventing AD are increasingly important. One strategy that appears promising in promoting healthy brain aging is exercise and physical activity. Evidence is accumulating that endurance exercise is beneficial to brain health (Laurin, Verreault, Lindsay, MacPherson, & Rockwood, 2001), and increased cardiorespiratory fitness is associated with increased brain volume in subjects with very mild to mild AD (Burns et al., 2008).
While enhancing cardiorespiratory fitness may be a strategy for preventing cognitive decline in AD, there is limited information available on the validity and reliability of cardiorespiratory fitness measures in this population. The gold standard measure of cardiorespiratory fitness is maximum oxygen consumption (VO2max) (Frankin, 2001), the highest rate of oxygen uptake attainable during maximal or exhaustive exercise (American College of Sports Medicine, 2005). If the subject becomes exhausted and ends the test prior to reaching the physiologic VO2max, the end of the test is called peak oxygen consumption (VO2peak). It is unknown if advanced age and cognitive difficulties in people with AD would limit their ability to fully participate in a standard graded exercise test to reliably assess VO2max or VO2peak.
Treadmill exercise testing has been found to be reliable in subjects with traumatic brain injury and mental retardation, although these subjects were very young (Fernhall, Millar, Tymeson, & Burkett, 1990; Mossberg & Greene, 2005). Traumatic brain injury and mental retardation are different disease processes than AD and would be expected to result in static rather than progressive cognitive symptoms. With AD, memory is impaired as is the ability to follow commands, however patients in the earliest stages of AD would be expected to respond to prompting and reminders to follow testing procedures. To our knowledge, no studies have assessed the reliability of peak treadmill exercise testing in subjects with AD. In our previous research on patients with very mild to mild AD (Burns, et al., 2008), we have found them to be capable of ambulating on a treadmill and completing peak treadmill exercise testing with 3 participants out of 74 (126 total peak exercise tests) identified as having EKG changes during testing. All 3 participants had negative follow-up testing in cardiology. The purpose of this study was to investigate the reliability of a graded peak treadmill exercise test in elderly people with early AD
Can screening and brief intervention lead to population-level reductions in alcohol-related harm?
A distinction is made between the clinical and public health justifications for screening and brief intervention (SBI) against hazardous and harmful alcohol consumption. Early claims for a public health benefit of SBI derived from research on general medical practitioners' (GPs') advice on smoking cessation, but these claims have not been realized, mainly because GPs have not incorporated SBI into their routine practice. A recent modeling exercise estimated that, if all GPs in England screened every patient at their next consultation, 96% of the general population would be screened over 10 years, with 70-79% of excessive drinkers receiving brief interventions (BI); assuming a 10% success rate, this would probably amount to a population-level effect of SBI. Thus, a public health benefit for SBI presupposes widespread screening; but recent government policy in England favors targeted versus universal screening, and in Scotland screening is based on new registrations and clinical presentation. A recent proposal for a national screening program was rejected by the UK National Health Service's National Screening Committee because 1) there was no good evidence that SBI led to reductions in mortality or morbidity, and 2) a safe, simple, precise, and validated screening test was not available. Even in countries like Sweden and Finland, where expensive national programs to disseminate SBI have been implemented, only a minority of the population has been asked about drinking during health-care visits, and a minority of excessive drinkers has been advised to cut down. Although there has been research on the relationship between treatment for alcohol problems and population-level effects, there has been no such research for SBI, nor have there been experimental investigations of its relationship with population-level measures of alcohol-related harm. These are strongly recommended. In this article, conditions that would allow a population-level effect of SBI to occur are reviewed, including their political acceptability. It is tentatively concluded that widespread dissemination of SBI, without the implementation of alcohol control measures, might have indirect influences on levels of consumption and harm but would be unlikely on its own to result in public health benefits. However, if and when alcohol control measures were introduced, SBI would still have an important role in the battle against alcohol-related harm
Landscape context outweighs local habitat quality in its effects on herbivore dispersal and distribution
Past studies with spatially structured herbivore populations have emphasized the primacy of intrinsic factors (e.g., patch quality), patch geometry (e.g., patch size and isolation), and more recently landscape context (e.g., matrix composition) in affecting local population abundance and dispersal rate. However, few studies have examined the relative importance of each factor, or how they might interact to affect herbivore abundance or dispersal. Here, we performed a factorial field experiment to examine the independent and interactive effects of patch quality (plant biomass, leaf protein, leaf phenolics) and matrix composition [mudflat or non-host grass (Bromus inermis)] on planthopper (Prokelisia crocea) emigration from host-plant patches (prairie cordgrass, Spartina pectinata). In addition, a field survey was conducted to examine the relative importance of patch quality, geography, and matrix composition on planthopper occupancy and density. In the experiment, we found that rates of emigration from low and intermediate quality patches were, on average, 21% percent higher for patches embedded in brome than mudflat. In contrast, the emigration rate was unaffected by matrix composition in nutrient-rich patches. Within matrix types, plant quality had little effect on emigration. In the survey, planthopper density and the patch occupancy rate of planthoppers increased nonadditively with increasing patch size and the percentage of the surrounding matrix composed of mudflat. This study suggests that landscape-level factors, such as the matrix, may be more important than factors intrinsic to the patches. © 2006 Springer-Verlag
Des Moines Area Community College Creative Writing Contest 1976-2001
Award-Winning Works For the Academic Year · 2000-2001https://openspace.dmacc.edu/creativewriting/1002/thumbnail.jp
Cardiorespiratory fitness and preserved medial temporal lobe volume in Alzheimer's Disease
This is not the final published version.Exercise and cardiorespiratory (CR) fitness may moderate age-related regional brain changes in nondemented older adults (ND). The relationship of fitness to Alzheimer's disease (AD) related brain change is understudied, particularly in the hippocampus which is disproportionately affected in early AD. The role of apolipoprotein E4 (apoE4) genotype in modulating this relationship is also unknown. Nondemented (n=56) and early-stage AD subjects (n=61) over age 65 had MRI and CR fitness assessments. Voxel-based morphometry (VBM) techniques were utilized to identify AD-related atrophy. We analyzed the relationship of CR fitness with white and gray matter within groups, assessed fitness-related brain volume change in areas most affected by AD-related atrophy, and then analyzed differential fitness-brain relationships between apoE4 carriers. Atrophy was present in the medial temporal, temporal, and parietal cortices in subjects with mild AD. There was a significant positive correlation of CR fitness with parietal and medial temporal volume in AD subjects. ND subjects did not have a significant relationship between brain volume and CR fitness in the global or SVC analyses. There was not a significant interaction for fitness Ă— apoE4 genotype in either group. In early-stage AD, cardiorespiratory fitness is associated with regional brain volumes in the medial temporal and parietal cortices suggesting that maintaining cardiorespiratory fitness may modify AD-related brain atrophy
Characterization of Glycosylation Profiles of HIV-1 Transmitted/Founder Envelopes by Mass Spectrometry
This is the published version, also available here: http://dx.doi.org/10.1128/JVI.05053-11.The analysis of HIV-1 envelope carbohydrates is critical to understanding their roles in HIV-1 transmission as well as in binding of envelope to HIV-1 antibodies. However, direct analysis of protein glycosylation by glycopeptide-based mass mapping approaches involves structural simplification of proteins with the use of a protease followed by an isolation and/or enrichment step before mass analysis. The successful completion of glycosylation analysis is still a major analytical challenge due to the complexity of samples, wide dynamic range of glycopeptide concentrations, and glycosylation heterogeneity. Here, we use a novel experimental workflow that includes an up-front complete or partial enzymatic deglycosylation step before trypsin digestion to characterize the glycosylation patterns and maximize the glycosylation coverage of two recombinant HIV-1 transmitted/founder envelope oligomers derived from clade B and C viruses isolated from acute infection and expressed in 293T cells. Our results show that both transmitted/founder Envs had similar degrees of glycosylation site occupancy as well as similar glycan profiles. Compared to 293T-derived recombinant Envs from viruses isolated from chronic HIV-1, transmitted/founder Envs displayed marked differences in their glycosylation site occupancies and in their amounts of complex glycans. Our analysis reveals that the glycosylation patterns of transmitted/founder Envs from two different clades (B and C) are more similar to each other than they are to the glycosylation patterns of chronic HIV-1 Envs derived from their own clades
Lessons Learned during the Transition to Online Learning in a University Nutrition and Exercise Department
In the spring semester of 2020, the COVID-19 pandemic led to an unprecedented shift from face-to-face learning to an instantaneous online learning environment. At the time, the department of Human Nutrition, Foods, and Exercise (HNFE) at Virginia Tech had few online class offerings. Twenty-nine Spring 2020 HNFE classes were transitioned from traditional face-to-face offerings to online delivery models. Many members of the HNFE faculty have strong pedagogical training, but the immediate pedagogical shift in the middle of the semester gave little time for adequate course design geared toward online learning. As such, the purpose of this study was to evaluate student perceptions of the transition to online learning. A departmental survey employing quantitative and qualitative questions was used to assess students’ learning experiences in the spring of 2020 and then re-employed at the conclusion of the Fall 2020 semester to re-assess students’ online course experience and identify if the department was improving in online course delivery. An additional component of the survey specifically evaluated students’ self-perceived motivation for learning. Examples of educational and logistical strategies in online learning environments implemented by instructors and findings of students’ experiences from both surveys will be shared
Scoping studies: advancing the methodology
Abstract
Background
Scoping studies are an increasingly popular approach to reviewing health research evidence. In 2005, Arksey and O'Malley published the first methodological framework for conducting scoping studies. While this framework provides an excellent foundation for scoping study methodology, further clarifying and enhancing this framework will help support the consistency with which authors undertake and report scoping studies and may encourage researchers and clinicians to engage in this process.
Discussion
We build upon our experiences conducting three scoping studies using the Arksey and O'Malley methodology to propose recommendations that clarify and enhance each stage of the framework. Recommendations include: clarifying and linking the purpose and research question (stage one); balancing feasibility with breadth and comprehensiveness of the scoping process (stage two); using an iterative team approach to selecting studies (stage three) and extracting data (stage four); incorporating a numerical summary and qualitative thematic analysis, reporting results, and considering the implications of study findings to policy, practice, or research (stage five); and incorporating consultation with stakeholders as a required knowledge translation component of scoping study methodology (stage six). Lastly, we propose additional considerations for scoping study methodology in order to support the advancement, application and relevance of scoping studies in health research.
Summary
Specific recommendations to clarify and enhance this methodology are outlined for each stage of the Arksey and O'Malley framework. Continued debate and development about scoping study methodology will help to maximize the usefulness and rigor of scoping study findings within healthcare research and practice
Screening and brief interventions for hazardous and harmful alcohol use in primary care: a cluster randomised controlled trial protocol
A large number of randomised controlled trials in health settings have consistently reported positive effects of brief intervention in terms of reductions in alcohol use. However,although alcohol misuse is common amongst offenders, there is limited evidence of alcohol brief interventions in the criminal justice field. This factorial pragmatic cluster randomised controlledtrial with Offender Managers (OMs) as the unit of randomisation will evaluate the effectiveness and cost-effectiveness of different models of screening to identify hazardous and harmful drinkers in probation and different intensities of brief intervention to reduce excessive drinking in probation clients.
Ninety-six OMs from 9 probation areas across 3 English regions (the NorthEast Region (n = 4) and London and the South East Regions (n = 5)) will be recruited. OMs will berandomly allocated to one of three intervention conditions: a client information leaflet control condition (n = 32 OMs); 5-minute simple structured advice (n = 32 OMs) and 20-minute brieflifestyle counselling delivered by an Alcohol Health Worker (n = 32 OMs). Randomisation will be stratified by probation area. To test the relative effectiveness of different screening methods all OMs will be randomised to either the Modified Single Item Screening Questionnaire (M-SASQ) orthe Fast Alcohol Screening Test (FAST). There will be a minimum of 480 clients recruited into the trial. There will be an intention to treat analysis of study outcomes at 6 and 12 months postintervention. Analysis will include client measures (screening result, weekly alcohol consumption,alcohol-related problems, re-offending, public service use and quality of life) and implementation measures from OMs (the extent of screening and brief intervention beyond the minimum recruitment threshold will provide data on acceptability and feasibility of different models of brief intervention). We will also examine the practitioner and organisational factors associated with successful implementation.The trial will evaluate the impact of screening and brief alcohol intervention in routine probation work and therefore its findings will be highly relevant to probation teams and thus the criminal justice system in the UK
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