3,878 research outputs found
In vivo validation of whole body composition estimates from dual-energy X-ray absorptiometry
No full text Prior, Barry M., Kirk J. Cureton, Christopher M. Modlesky, Ellen M. Evans, Mark A. Sloniger, Michael Saunders, and Richard D. Lewis. In vivo validation of whole body composition estimates from dual-energy X-ray absorptiometry. J. Appl. Physiol. 83(2): 623–630, 1997.—We validated whole body composition estimates from dual-energy X-ray absorptiometry (DEXA) against estimates from a four-component model to determine whether accuracy is affected by gender, race, athletic status, or musculoskeletal development in young adults. Measurements of body density by hydrostatic weighing, body water by deuterium dilution, and bone mineral by whole body DEXA were obtained in 172 young men ( n = 91) and women ( n = 81). Estimates of body fat (%Fat) from DEXA (%FatDEXA) were highly correlated with estimates of body fat from the four-component model [body density, total body water, and total body mineral (%Fatd,w,m); r = 0.94, standard error of the estimante (SEE) = 2.8% body mass (BM)] with no significant difference between methods [mean of the difference ± SD of the difference = −0.4 ± 2.9 (SD) % BM, P = 0.10] in women and men. On the basis of the comparison with %Fatd,w,m, estimates of %FatDEXA were slightly more accurate than those from body density ( r = 0.91, SEE = 3.4%; mean of the difference ± SD of the difference = −1.2 ± 3.4% BM). Differences between %FatDEXA and %Fatd,w,m were weakly related to body thickness, as reflected by BMI ( r= −0.34), and to the percentage of water in the fat-free mass ( r = −0.51), but were not affected by race, athletic status, or musculoskeletal development. We conclude that body composition estimates from DEXA are accurate compared with those from a four-component model in young adults who vary in gender, race, athletic status, body size, musculoskeletal development, and body fatness. </jats:p
Book Review: Grimwood, M and McHanwell, S. (2024) Evidencing Teaching Achievements in Higher Education. Critical Publishing.
No full textBook Review: Grimwood, M and McHanwell, S. (2024) Evidencing Teaching Achievements in Higher Education. Critical Publishing.
Christopher Little
Manchester Metropolitan University
Corresponding author: [email protected]
A Mixed-Method Approach for Quantifying Illegal Fishing and Its Impact on an Endangered Fish Species
No full textIllegal harvest is recognized as a widespread problem in natural resource management. The use of multiple methods for quantifying illegal harvest has been widely recommended yet infrequently applied. We used a mixed-method approach to evaluate the extent, charac- ter, and motivations of illegal gillnet fishing in Lake Hovsgol National Park, Mongolia and its impact on the lake’s fish populations, especially that of the endangered endemic Hovsgol grayling (Thymallus nigrescens). Surveys for derelict fishing gear indicate that gillnet fishing is widespread and increasing and that fishers generally use 3–4 cm mesh gillnet. Interviews with resident herders and park rangers suggest that many residents fish for subsistence during the spring grayling spawning migration and that some residents fish commercially year-round. Interviewed herders and rangers generally agree that fish population sizes are decreasing but are divided on the causes and solutions. Biological monitoring indicates that the gillnet mesh sizes used by fishers efficiently target Hovsgol grayling. Of the five species sampled in the monitoring program, only burbot (Lota lota) showed a significant decrease in population abundance from 2009–2013. However, grayling, burbot, and roach (Rutilus ruti- lus) all showed significant declines in average body size, suggesting a negative fishing impact. Data-poor stock assessment methods suggest that the fishing effort equivalent to each resident family fishing 50-m of gillnet 11–15 nights per year would be sufficient to over- exploit the grayling population. Results from the derelict fishing gear survey and interviews suggest that this level of effort is not implausible. Overall, we demonstrate the ability for a mixed-method approach to effectively describe an illegal fishery and suggest that these methods be used to assess illegal fishing and its impacts in other protected areas.Peer reviewe
Teacher formative assessment: the missing link in response to intervention
No full textResponse to Intervention (RtI) focuses on the assessment, intervention, and progress monitoring of student academic performance and social behavior. Despite requiring highly-qualified personnel for successful implementation, the implementation of Rtl has not focused on applying its foundational principles towards promoting teacher effectiveness through assessment, intervention, and progress monitoring of teacher classroom practice. Compounding this problem is the lack of availability of reliable and valid teacher assessments to apply in an Rtl model for teacher professional development. This chapter provides a rationale for applying RtI principles to teacher professional development and how teacher formative assessment can improve educator effectiveness, student learning, and social behaviors. The Classroom Strategies Scale (CSS, Reddy & Dudek, 2014), a new multidimensional assessment of instructional and behavioral management practices is discussed as an example of one promising tool for promoting teachers professional development within an Rtl model. We offer a synthesis of the theory, research, and evidence of reliability and validity of the CSS. The application of teacher formative assessment in job-embedded professional development/coaching models for schools is discussed. Finally, implications for practice and research are outlined.Peer reviewe
Oregon Justice Reinvestment Initiative: return on investment
No full textsubmitted to: Oregon Criminal Justice Commission ; principal investigator: Mauri Matsuda, Ph.D. ; co-investigators: Christopher Campbell, Ph.D., Christopher Dollar, M.S., Mark Leymon, Ph.D., Brian Renauer, Ph.D.This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references (pages 38-39).Funded by: Oregon Criminal Justice Commission.Mode of access: Internet from the Oregon Government Publications Collection.Text in English
Pannexin-1 and P2X7-Receptor Are Required for Apoptotic Osteocytes in Fatigued Bone to Trigger RANKL Production in Neighboring Bystander Osteocytes
No full textOsteocyte apoptosis is required to induce intracortical bone remodeling after microdamage in animal models, but how apoptotic osteocytes signal neighboring “bystander” cells to initiate the remodeling process is unknown. Apoptosis has been shown to open pannexin-1 (Panx1) channels to release adenosine diphosphate (ATP) as a “find me” signal for phagocytic cells. To address whether apoptotic osteocytes use this signaling mechanism, we adapted the rat ulnar fatigue-loading model to reproducibly introduce microdamage into mouse cortical bone and measured subsequent changes in osteocyte apoptosis, receptor activator of NF-kB ligand (RANKL) expression and osteoclastic bone resorption in wild-type (WT; C57Bl/6) mice and in mice genetically deficient in Panx1 (Panx1KO). Mouse ulnar loading produced linear microcracks comparable in number and location to the rat model. WT mice showed increased osteocyte apoptosis and RANKL expression at microdamage sites at 3 days after loading and increased intracortical remodeling and endocortical tunneling at day 14. With fatigue, Panx1KO mice exhibited levels of microdamage and osteocyte apoptosis identical to WT mice. However, they did not upregulate RANKL in bystander osteocytes or initiate resorption. Panx1 interacts with P2X7R in ATP release; thus, we examined P2X7R-deficient mice and WT mice treated with P2X7R antagonist Brilliant Blue G (BBG) to test the possible role of ATP as a find-me signal. P2X7RKO mice failed to upregulate RANKL in osteocytes or induce resorption despite normally elevated osteocyte apoptosis after fatigue loading. Similarly, treatment of fatigued C57Bl/6 mice with BBG mimicked behavior of both Panx1 KO and P2X7RKO mice; BBG had no effect on osteocyte apoptosis in fatigued bone but completely prevented increases in bystander osteocyte RANKL expression and attenuated activation of resorption by more than 50%. These results indicate that activation of Panx1 and P2X7R are required for apoptotic osteocytes in fatigued bone to trigger RANKL production in neighboring bystander osteocytes and implicate ATP as an essential signal mediating this process.Peer reviewe
The protective effect of a diet rich in fish oil in an amphetamine toxicity model of Parkinson’s disease
No full textParkinson’s disease is a neurodegenerative disorder that damages the dopaminergic neurons of the substantia nigra and their axonal projections to the striatum. This cell death results in significant motor deficits that include muscular rigidity, resting tremor, and akinesia. Although there is no known cure for Parkinson’s disease, evidence from epidemiological studies suggests that consumption of fish oil, which is rich in omega-3 polyunsaturated fatty acids (PUFAs), may help to reduce the risk of this debilitating disorder. Furthermore, research using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA) models of Parkinson’s disease supports this conclusion. Consequently, this dissertation examined the potential protective effect of fish oil in an amphetamine-toxicity model of Parkinson’s disease. In Experiment 1, mice were administered a diet rich in either corn oil or fish oil for one week and then were treated with either amphetamine or saline. After sacrifice 72 hours later, striatal tissue was assayed for neurochemical content using HPLC. It was determined that fish oil protects against amphetamine-induced depletions of dopamine and its metabolites. Given the role of oxidative stress in amphetamine toxicity, this protection may be a result of the antioxidant properties of fish oil. Experiment 2, in addition to successfully replicating this effect, extended the protective effect of fish oil to behavioral and physiological measures. More specifically, a diet rich in fish oil significantly altered amphetamine’s impact on behaviors including oral dyskinesia, self biting, stereotypy, and backwards walking; it also mitigated amphetamine-induced changes in dermal temperature. These results suggest that fish oil can moderate the elevated dopaminergic activity caused by amphetamine administration. Experiment 3 was designed to examine the time course of protection afforded by the fish oil-rich diet, and it was discovered that the protective effect of fish oil develops between 1 and 3 days of consumption. Experiment 4 was performed to determine if fish oil alters amphetamine-induced increases in oxidative stress and dopamine release. Fish oil did not impact these measures, indicating that other mechanisms may be responsible for the observed protection. Collectively, these findings indicate that the consumption of fish oil offers protection against amphetamine toxicity in a model of Parkinson’s disease.Ph. D.Includes bibliographical referencesIncludes vitaby Christopher M. Medveck
Serum 25 (OH)D Concentrations in girls aged 4 to 8 years living in the southeast USA
No full textBackground: Evidence suggests that adults and adolescents throughout the United States are at risk of poor vitamin D status. However, vitamin D concentrations in young American children have not been assessed.\ud
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Objective: The relations between serum 25-hydroxyvitamin D [25(OH)D] and bone were examined in prepubertal girls.\ud
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Design: In the present cross-sectional study, serum 25(OH)D concentration was assessed in 168 prepubertal girls aged 4–8 y living in the southeastern United States with the use of radioimmunoassay. Bone area, bone mineral content, and areal bone mineral density were measured from total body, lumbar spine, proximal femur, and forearm with dual-energy X-ray absorptiometry. Data were analyzed with analysis of variance, analysis of covariance, stepwise multiple regression, and partial correlations.\ud
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Results: The mean (±SD) serum 25(OH)D was 93.8 ± 28.1 nmol/L (range: 31.1–181.4 nmol/L). In a multiple regression analysis, race and season were the strongest predictors of vitamin D status. The black girls had lower mean 25(OH)D values than did the white girls (P < 0.01), and 25(OH)D values were significantly different in the total sample between the seasons (P < 0.001), ranging from 74.4 nmol/L during the winter months to 107 nmol/L during the summer. After adjustment for season, age, race, and body mass index, 25(OH)D values were negatively correlated with forearm bone mineral content (r = –0.18; P = 0.02).\ud
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Conclusions: Unlike prior reports of adults and adolescents living in the southeastern United States, vitamin D status was adequate in the children of the present study. 25(OH)D concentrations were not positively associated with higher bone mineral
Heritability and Linkage Analysis of Appendicitis Utilizing Age at Onset
No full textAppendicitis usually afflicts the young, but there is a large tail in the distribution of onset age. The genetics of this disease are still not well understood. A heritability analysis and genome wide linkage analysis of a large twin dataset was undertaken. Treating age of onset of appendicitis as a censored survival trait revealed a heritability of 0.21, and found evidence of linkage to Chromosome 1p37.3. Author(s): Christopher Oldmeadow 1 * | Kerrie Mengersen 2 | Nicholas Martin 3 | David L. Duffy
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Introduction
No full textByline: Charles B. Nemeroff, Christopher M. O'Connor Author Affiliation: Atlanta, Ga, and Durham, NC From the Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta; and Duke University Medical Center, Durham, NC Article Note: (footnote) [star] Reprint requests: Charles B. Nemeroff, MD, PhD, Psychiatry and Behavioral Sciences, Emory University School of Medicine,1639 Pierce Drive, Atlanta, GA 30322-4990. E-mail: [email protected], [star][star] Am Heart J 2000;140:S55-6.ProfessionalAcademi
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