373 research outputs found

    Anuran artifacts of preservation: 27 years later

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    Measurements made on preserved anuran specimens are often used in studies of systematics, ecology and evolution. Here, we examine the effect of preservation on one of the most common measurement of frogs, snout-urostyle length (SUL). Preservation had significanteffects on the SUL of 13 of the 14 species of North American frogs included in this study, with all species decreasing in SUL by 0.31-5.62%. Smaller frog species did not shrink proportionally more or less than larger species. Absolute shrinkage was correlated with SUL and was greater in larger species. Within species, percent shrinkage was not significantly correlated with SUL in 10 species, but significantly greater for larger individuals in 3 species, and decreased with size in 1 species. Absolute shrinkage was statistically greater for larger individuals in 4 species. Our results agree with studies of morphological permutations in fish which show that most preservation-related changes take place within the first few months after initial preservation. We suggest that the potential consequences of using preserved specimens in research must be considered and that future studies continue to examine preservation effects, not only on frogs, but on all preserved specimens used in scientific investigations

    Artefatos de preservação em anuros: 27 anos depois

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    Measurements made on preserved anuran specimens are often used in studies of systematics, ecology and evolution. Here, we examine the effect of preservation on one of the most common measurement of frogs, snout-urostyle length (SUL). Preservation had significant effects on the SUL of 13 of the 14 species of North American frogs included in this study, with all species decreasing in SUL by 0.31-5.62%. Smaller frog species did not shrink proportionally more or less than larger species. Absolute shrinkage was correlated with SUL and was greater in larger species. Within species, percent shrinkage was not significantly correlated with SUL in 10 species, but significantly greater for larger individuals in 3 species, and decreased with size in 1 species. Absolute shrinkage was statistically greater for larger individuals in 4 species. Our results agree with studies of morphological permutations in fish which show that most preservation-related changes take place within the first few months after initial preservation. We suggest that the potential consequences of using preserved specimens in research must be considered and that future studies continue to examine preservation effects, not only on frogs, but on all preserved specimens used in scientific investigations.Medidas tomadas em espécimes preservados são frequentemente usadas em estudos de sistemática, ecologia e evolução. Examinamos aqui o efeito da preservação sobre uma das medidas mais comumente feitas em anuros, o comprimento rostro-clocal (CRC). A preservação teve efeitos significativos sobre o CRC de 13 das 14 espécies de anuros norteamericanos incluídas no estudo, com uma diminuição de 0,31 a 5,62% em todas as espécies. As espécies de menor porte não encolheram proporcionalmente mais nem menos que as espécies maiores. A redução absoluta de tamanho mostrou-se correlacionada com o CRC, tendo sido maior em espécies de maior porte. Dentro de cada espécie, a porcentagem de redução de tamanho não se mostrou significativamente correlacionada com o CRC em 10 espécies, mas foi significativamente maior para os indivíduos de maior porte em três espécies e diminuiu com o tamanho em uma espécie. A redução absoluta de tamanho foi estatisticamente maior para os indivíduos maiores em quatro espécies. Nossos resultados concordam com os dados obtidos em estudos de permutações morfológicas em peixes, que mostraram que a maioria das modificações relacionadas à preservação ocorre durante os primeiros meses após a preservação. Sugerimos que as consequências potenciais do uso de espécimes preservados na pesquisa devem ser consideradas, e que estudos futuros continuem a examinar os efeitos da preservação, não apenas em anuros, mas em todos os espécimes preservados utilizados em investigações científicas

    Performance of the Halex in Logitudinal Studies of Older Adults

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    Goal: The Halex is an indicator of health status that combines self-rated health and activity limitations, which has been used by NCHS to predict future years of healthy life. The scores for each health state were developed based on strong assumptions, notably that a person in excellent health with ADL disabilities is as healthy as a person in poor health with no disabilities. Our goal was to examine the performance of the Halex as a longitudinal measure of health for older adults, and to improve the scoring if necessary. Methods: We used data from the Cardiovascular Health Study (CHS) to compare the relationship of baseline health to health 2 years later. Subject ages ranged from 65 to 103 (mean age 75). A total of 40,827 transitions were available for analysis. We examined whether Halex scores at time 0 were related monotonically to scores two years later, and iterated the original scores to improve the fit over time. Findings: The original Halex scores were not consistent over time. Persons in excellent health with ADL limitations were much healthier 2 years later than people in poor health with no limitations, even though they had been assumed to have identical health. People with ADL limitations had higher scores than predicted. The assumptions made in creating the Halex were not upheld in the data. Conclusions: The new iterated scores are specific to older adults, are appropriate for longitudinal data, and are relatively assumption-free. We recommend the use of these new scores for longitudinal studies of older adults that use the Halex health states

    Collaborate With Whom? Clergy Responses to Psychologist Characteristics (Chapter 2 of Psychology and the Church)

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    Some clergy and psychologists are willing to collaborate in providing for people under their care and some are reticent. The purpose of this research is to see if clergy are more likely to collaborate with psychologists of a particular sex or training background. Six groups of clergy were given written descriptions of a psychologist that varied on these two dimensions-the institution from which the psychologist received training and sexand were then asked to rate how likely they would be to participate in 7 collaborative scenarios with the psychologist. No group differences were found. Furthermore, clergy characteristics were not significantly related to their likelihood of collaborating with psychologists. Differences were observed among the 7 collaborative scenarios, suggesting that clergy are more interested in some forms of collaboration than others. It appears that idiographic relational factors are ultimately more important than general demographic categories in establishing clergy-psychologist collaboration

    High Dimensional Classification of Structural MRI Alzheimer’s Disease Data Based on Large Scale Regularization

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    In this work we use a large scale regularization approach based on penalized logistic regression to automatically classify structural MRI images (sMRI) according to cognitive status. Its performance is illustrated using sMRI data from the Alzheimer Disease Neuroimaging Initiative (ADNI) clinical database. We downloaded sMRI data from 98 subjects (49 cognitive normal and 49 patients) matched by age and sex from the ADNI website. Images were segmented and normalized using SPM8 and ANTS software packages. Classification was performed using GLMNET library implementation of penalized logistic regression based on coordinate-wise descent optimization techniques. To avoid optimistic estimates classification accuracy, sensitivity, and specificity were determined based on a combination of three-way split of the data with nested 10-fold cross-validations. One of the main features of this approach is that classification is performed based on large scale regularization. The methodology presented here was highly accurate, sensitive, and specific when automatically classifying sMRI images of cognitive normal subjects and Alzheimer disease (AD) patients. Higher levels of accuracy, sensitivity, and specificity were achieved for gray matter (GM) volume maps (85.7, 82.9, and 90%, respectively) compared to white matter volume maps (81.1, 80.6, and 82.5%, respectively). We found that GM and white matter tissues carry useful information for discriminating patients from cognitive normal subjects using sMRI brain data. Although we have demonstrated the efficacy of this voxel-wise classification method in discriminating cognitive normal subjects from AD patients, in principle it could be applied to any clinical population

    Fall Risk Classification in Community-Dwelling Older Adults: Validation of PROMIS-PF and Performance-Based Outcomes

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    Purpose: To validate the use of the PROMIS-PF in its ability to screen and classify fall risk in Strong For Life exercise participants consistent with STEADI and FES-I classificatio

    Evolution of the Hepatitis E virus hypervariable region

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    The presence of a hypervariable (HVR) region within the genome of hepatitis E virus (HEV) remains unexplained. Previous studies have described the HVR as a proline-rich spacer between flanking functional domains of the ORF1 polyprotein. Others have proposed that the region has no function, that it reflects a hypermutable region of the virus genome, that it is derived from the insertion and evolution of host sequences or that it is subject to positive selection. This study attempts to differentiate between these explanations by documenting the evolutionary processes occurring within the HVR. We have measured the diversity of HVR sequences within acutely infected individuals or amongst sequences derived from epidemiologically linked samples and, surprisingly, find relative homogeneity amongst these datasets. We found no evidence of positive selection for amino acid substitution in the HVR. Through an analysis of published sequences, we conclude that the range of HVR diversity observed within virus genotypes can be explained by the accumulation of substitutions and, to a much lesser extent, through deletions or duplications of this region. All published HVR amino acid sequences display a relative overabundance of proline and serine residues that cannot be explained by a local bias towards cytosine in this part of the genome. Although all published HVRs contain one or more SH3-binding PxxP motifs, this motif does not occur more frequently than would be expected from the proportion of proline residues in these sequences. Taken together, these observations are consistent with the hypothesis that the HVR has a structural role that is dependent upon length and amino acid composition, rather than a specific sequence

    Buffalo Reading List

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    This reading list gathers together literature focused on buffalo (also known as bison) to support ongoing efforts to restore this iconic species to its keystone cultural and ecological role. The books and articles compiled here are grounded in a wide range of academic disciplines and approaches, representing many distinct ways of thinking about buffalo within the realm of Western sciences. This is not intended to be an exhaustive account of what is known about buffalo, much of which is held in Indigenous knowledge systems and communities. This academic list is designed as a resource for those working towards buffalo restoration, including conservation practitioners, researchers, parks and government officials, and Tribal communities. It is divided into categories according to either discipline or thematic focus, each containing a subset of pertinent literature. Topics include the paleobiology of bison, histories of buffalo loss, relationships between Indigenous Peoples and buffalo, buffalo restoration and reintroduction, buffalo ecology, buffalo and climate change, governance and human dimensions of buffalo, bison and cattle, bison as livestock, and the genetics of bison. This list is intended as a living document to grow with the increasingly rich scholarship on buffalo, and will be updated regularly

    EFFECTS OF INTENSIVE DIET AND EXERCISE ON KNEE JOINT LOADS, INFLAMMATION, AND CLINICAL OUTCOMES AMONG OVERWEIGHT AND OBESE ADULTS WITH KNEE OSTEOARTHRITIS

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    Importance Knee osteoarthritis (OA), a common cause of chronic pain and disability, has biomechanical and inflammatory origins and is exacerbated by obesity. Objective To determine whether a ≥10% reduction in body weight induced by diet, with or without exercise, would improve mechanistic and clinical outcomes more than exercise alone. Design, Setting, and Participants Single-blind, 18-month, randomized clinical trial at Wake Forest University between July 2006 and April 2011. The diet and exercise interventions were center-based with options for the exercise groups to transition to a home-based program. Participants were 454 overweight and obese older community-dwelling adults (age ≥55 years with body mass index of 27-41) with pain and radiographic knee OA. Interventions Intensive diet-induced weight loss plus exercise, intensive diet-induced weight loss, or exercise. Main Outcomes and Measures Mechanistic primary outcomes: knee joint compressive force and plasma IL-6 levels; secondary clinical outcomes: self-reported pain (range, 0-20), function (range, 0-68), mobility, and health-related quality of life (range, 0-100). Results Three hundred ninety-nine participants (88%) completed the study. Mean weight loss for diet + exercise participants was 10.6 kg (11.4%); for the diet group, 8.9 kg (9.5%); and for the exercise group, 1.8 kg (2.0%). After 18 months, knee compressive forces were lower in diet participants (mean, 2487 N; 95% CI, 2393 to 2581) compared with exercise participants (2687 N; 95% CI, 2590 to 2784, pairwise difference [Δ]exercise vs diet = 200 N; 95% CI, 55 to 345; P = .007). Concentrations of IL-6 were lower in diet + exercise (2.7 pg/mL; 95% CI, 2.5 to 3.0) and diet participants (2.7 pg/mL; 95% CI, 2.4 to 3.0) compared with exercise participants (3.1 pg/mL; 95% CI, 2.9 to 3.4; Δexercise vs diet + exercise = 0.39 pg/mL; 95% CI, −0.03 to 0.81; P = .007; Δexercise vs diet = 0.43 pg/mL; 95% CI, 0.01 to 0.85, P = .006). The diet + exercise group had less pain (3.6; 95% CI, 3.2 to 4.1) and better function (14.1; 95% CI, 12.6 to 15.6) than both the diet group (4.8; 95% CI, 4.3 to 5.2) and exercise group (4.7; 95% CI, 4.2 to 5.1, Δexercise vs diet + exercise = 1.02; 95% CI, 0.33 to 1.71; Ppain = .004; 18.4; 95% CI, 16.9 to 19.9; Δexercise vs diet + exercise, 4.29; 95% CI, 2.07 to 6.50; Pfunction < .001). The diet + exercise group (44.7; 95% CI, 43.4 to 46.0) also had better physical health-related quality of life scores than the exercise group (41.9; 95% CI, 40.5 to 43.2; Δexercise vs diet + exercise = −2.81; 95% CI, −4.76 to −0.86; P = .005). Conclusions and Relevance Among overweight and obese adults with knee OA, after 18 months, participants in the diet + exercise and diet groups had more weight loss and greater reductions in IL-6 levels than those in the exercise group; those in the diet group had greater reductions in knee compressive force than those in the exercise group
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