1,721,002 research outputs found
Historical biogeography of the Late Cretaceous vertebrates of India : Comparison of geophysical and paleontological data
No full textFil: Verma, Omkar. Geology Discipline Group. School of Sciences. Indira Gandhi National Open University. New Delhi; IndiaFil: Khosla, Ashu. Department of Geology. Centre for Advanced Studies. Panjab University. Chandigarh; IndiaFil: Goin, Francisco Javier. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Kaur, Jasdeep. Department of Geology. Centre for Advanced Studies. Panjab University. Chandigarh; Indi
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Forearm vascular blood flow and conductance responses in Hispanic-White individuals
Full text linkHispanic-White Americans (HW) individuals have the highest prevalence, mortality, and diabetic complications when compared to other racial and ethnic groups. The underlying mechanisms for this disproportionately high incidence of T2D in HW individuals remains unknown. Impaired vascular dysfunction and a lack of NO bioavailability is a well-known hallmark of T2D; yet few studies have investigated vascular function and NO bioavailability in the HW population. Equivocal results have been previously reported using flow-mediated dilation (FMD) in the HW population, a measure of endothelium-dependent, nitric oxide-mediated vasodilation through a non-exercise-based stimulus. However, exercise-based reactive hyperemia using a rhythmic handgrip exercise (RHG) protocol has been shown to be a valid assessment of vascular function and bioactive NO, having been used to show racial and ethnic differences in vascular function previously. Therefore, we aim to extend the previous findings by evoking a stepwise increase in shear stress during three exercise workloads to investigate the vascular function in young, healthy HW during exercise. We tested the hypothesis that HW individuals would exhibit an attenuated forearm blood flow (FBF) and forearm vascular conductance (FVC) compared to non-Hispanic White (NHW) individuals during rhythmic handgrip exercise (RHG). FBF, heart rate, and mean arterial pressure (MAP) were measured in young, healthy HW (n = 18 (10M/8F)) as well as in young, healthy NHW (n = 18 (8M/10F)) during three trials of RHG performed at 15%, 30%, and 45% of their maximum voluntary contraction (MVC). In men, baseline FBF and FVC (calculated as FBF/MAP, p < 0.01), was lower in HW. Normalized FBF to forearm fat-free mass through DEXA was also significantly lower in HW (p <0.01) However, MAP and MVCs (p = 0.65, p = 0.23) were not different between groups. Similarly, in women, baseline FBF (p = 0.34), MAP (p = 0.50), FVC (p = 0.43), and MVC (p = 0.54) were not significantly different between groups. In men, an intensity-dependent increase in FVC and FBF was observed, with HW men possessing a higher relative FVC increase from baseline when compared to the NHW men (e.g., %Δ FVC 45%MVC: 406 ± 32 in HW men, 290 ± 24 in NHW men; intensity effect: p < 0.01, ethnicity effect: p < 0.05, interaction effect: p = 0.16). However, MAP increase was not significant in men. (e.g., DMAP at 45% MVC: +12 ± 4 mmHg in HW men, +10 ± 2 mmHg in NHW men, p = 0.60) In women, a similar intensity-dependent increase in FVC and FBF was observed (e.g., %Δ FVC 45%MVC: 374 ± 44 in HW women, 392 ± 58 in NHW women; intensity effect: p < 0.01, ethnicity effect: p = 0.97, interaction effect: p = 0.87). Increase in MAP was also not significant in women. (e.g., ΔMAP 45%MVC + 7 ± 3 mmHg in HW women, + 12 ± 2 mmHg in NHW women, p = 0.16) in young, healthy HW during exercise. We tested the hypothesis that HW individuals would exhibit an attenuated forearm blood flow (FBF) and forearm vascular conductance (FVC) compared to non-Hispanic White (NHW) individuals during rhythmic handgrip exercise (RHG). FBF, heart rate, and mean arterial pressure (MAP) were measured in young, healthy HW (n = 18 (10M/8F)) as well as in young, healthy NHW (n = 18 (8M/10F)) during three trials of RHG performed at 15%, 30%, and 45% of their maximum voluntary contraction (MVC). In men, baseline FBF and FVC (calculated as FBF/MAP, p < 0.01), was lower in HW. Normalized FBF to forearm fat-free mass through DEXA was also significantly lower in HW (p <0.01) However, MAP and MVCs (p = 0.65, p = 0.23) were not different between groups. Similarly, in women, baseline FBF (p = 0.34), MAP (p = 0.50), FVC (p = 0.43), and MVC (p = 0.54) were not significantly different between groups. In men, an intensity-dependent increase in FVC and FBF was observed, with HW men possessing a higher relative FVC increase from baseline when compared to the NHW men (e.g., %Δ FVC 45%MVC: 406 ± 32 in HW men, 290 ± 24 in NHW men; intensity effect: p < 0.01, ethnicity effect: p < 0.05, interaction effect: p = 0.16). However, MAP increase was not significant in men. (e.g., DMAP at 45% MVC: +12 ± 4 mmHg in HW men, +10 ± 2 mmHg in NHW men, p = 0.60) In women, a similar intensity-dependent increase in FVC and FBF was observed (e.g., %Δ FVC 45%MVC: 374 ± 44 in HW women, 392 ± 58 in NHW women; intensity effect: p < 0.01, ethnicity effect: p = 0.97, interaction effect: p = 0.87). Increase in MAP was also not significant in women. (e.g., ΔMAP 45%MVC + 7 ± 3 mmHg in HW women, + 12 ± 2 mmHg in NHW women, p = 0.16) These findings indicate that FBF and FVC responses during rhythmic handgrip exercise is preserved in young Hispanic-white men and women compared to their non-Hispanic-white counterparts.Kinesiology and Health Educatio
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The effects of exercise on type II diabetes mellitus
Full text linkIn recent decades, there has been a drastic incline in numerous diseases such as obesity, hypertension, and type II diabetes mellitus. Type II diabetes mellitus (T2DM) is a chronic metabolic condition that affects over 37 million people in the United States every year. T2DM affects the body’s ability to respond to an increase in blood sugar, by either having a resistance to insulin, or no longer being able to produce insulin at all in type I and type II diabetes. Since T2DM is a such a widespread problem not just in the US but across the globe, there are many modalities in place that attempt to control a person’s diabetes or mitigate the potential consequences that arise from chronic hyperglycemia (excess glucose in the bloodstream). Among these modalities include behavioral changes, dietary changes, pharmacological interventions, and a modality that is often overlooked, exercise prescription. Exercise is prescribed to patients with T2DM with the intent to attenuate the body’s resistance to insulin through a number of physiological responses to both acute and chronic exercise. This report will outline what type II diabetes mellitus is, how it affects the body, common exercise prescription for patients with T2DM and what impact that exercise will have on the body by affecting several physiological processes.Kinesiology and Health Educatio
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Differences in vascular function in middle-aged Hispanic and non-Hispanic White adults
Full text linkHispanics in the United States experience increased risk for the development of cardiovascular disease and have the highest prevalence of type II diabetes in the country. It has yet to be fully understood the underlying mechanisms for this increased prevalence of cardiovascular disease. It has been previously shown that reduction in endothelial function may present themselves prior to the onset of cardiovascular disease symptoms. Prior studies investigating vascular function during rest and exercise have found equivocal results, and their generalizability is limited by their methods. No study has yet to measure vascular function during exercise in healthy middle aged Hispanic and Non-Hispanic White (NHW) adults. We hypothesized that with an increase in age, healthy middle aged Hispanic adults would demonstrate an attenuation in vascular function during exercise and rest compared to healthy middle aged non-Hispanic White adults. We recruited 12 healthy middle aged Hispanic adults (8 women) and 12 healthy middle aged non-Hispanic white adults (7 women). We measured vascular function during exercise, resting endothelial function, arterial stiffness, and sympathetic activation in our cohort of middle aged Hispanic and NHW adults. We found no statistical difference in vascular function in response to exercise (ex. ∆% Forearm Vascular Conductance at 45% maximum voluntary contraction: 541.80 ± 63.2 in NHW and 483 ± 53.1 in Hispanics, intensity effect p < 0.001, ethnicity effect: p = 0.91, interaction effect: p = 0.28). Our Hispanic cohort exhibited significantly higher resting endothelial function by flow mediated dilation compared to the NHW cohort (5.1 ± 0.9 in NHW and 8.66 ± 1.3 in Hispanics, p = 0.04). We found no statistical difference in sympathoexcitation to a non-exercise stimulus via the cold pressor test (∆ mean arterial pressure at 120s: 24 ± 3 in NHW and 26 ± 4 in Hispanics, time effect: p < 0.01, ethnicity effect: p = 0.38, interaction effect: p = 0.58). These findings indicate that contrary to our hypothesis, our cohort of middle-aged experienced a preservation in vascular function during exercise compared to middle aged non-Hispanic White participants.Kinesiology and Health Educatio
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The exercise pressor response and cardiac autonomic function in young healthy Hispanic adults
Full text linkHispanic population comprises 19.1% of the US population. It is the largest ethnic population in the United States and is predicted to comprise one third of US population by the year 2050. Incorporating the larger part of the US population, Hispanic population is at a high risk of developing various risk factors such as hypertension, obesity and type 2 diabetes overburdened by high incidence of uncontrolled hypertension, increasing the health concern in this population in the coming years. However, no studies have examined autonomic function and its influence in Hispanic population. The following two studies in this thesis are dedicated in examining the autonomic function in Hispanic adults. In the first study, we examined the exercise pressor response during static handgrip exercise, muscle metaboreflex activation during post exercise ischemia and cold pressor response in young healthy Hispanic/Latino adults and non-Hispanic White adults. We found that the exercise pressor response and muscle metaboreflex activation are preserved in young healthy Hispanic/Latino adults while cold pressor response is exaggerated in them. In the second study, we examined the baroreflex sensitivity by sequence method and heart rate variability in time and frequency domain in young healthy Hispanic/Latino and non-Hispanic White adults. In this study, we discovered the baroreflex sensitivity and heart rate variability to be preserved in young healthy Hispanic adults. Thorough examination of our two studies suggests that the augmented sympathoexcitation to non-exercise stimulus (cold pressor response) can be one of the possible mechanisms for the higher health issues in this population.Kinesiology and Health Educatio
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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