bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling data from different sites, times or studies: weighted vs. unweighted regression
Authors: Fletcher David , Dixon Philip M. 
Published: July 2011

Summary1. We consider the use of weighted regression when modelling data from different sites, times or studies. Our primary focus is on the coverage rate of the 95% confidence interval for the slope parameter when we have a single predictor variable. We use simulation to assess this coverage rate for both weighted and unweighted regression, across a range of scenarios likely to be encountered in ecology.2. Our results are surprising: unweighted regression will often be more reliable than weighted regression. The well‐known advantages of weighted regression are offset by having to estimate the process error variance. Although unweighted regression involves assuming that the measurement error variances are equal, the coverage rate is remarkably robust to departures from this assumption. Unweighted regression will often be more robust because it does not make use of potentially poor information on the measurement error variances. The only situation in which unweighted regression will perform poorly is when there is a strong relationship between the precision of an estimate and its leverage in the regression. We propose a simple diagnostic tool to assess when this might be the case.3. The implications of our results are important in a management context as they indicate the benefits obtained from using a simple, readily understood approach to combining information.
Structure de poids à la Bondarko sur les motifs de Beilinson
Authors: Hébert David 
Published: July 2011

AbstractBondarko defines and studies the notion of weight structure and he shows that there exists a weight structure over the category of Voevodsky motives with rational coefficients (over a field of characteristic 0). In this paper we extend this weight structure to the category of Beilinson motives (for any scheme of finite type over a base scheme which is excellent of dimension at most two) introduced and studied by Cisinsky and Déglise. We also check the weight exactness of the Grothendieck operations.
Algèbres simplicialesS1-équivariantes, théorie de de Rham et théorèmes HKR multiplicatifs
Authors: Toën Bertrand , Vezzosi Gabriele 
Published: July 2011

AbstractThis work establishes a comparison between functions on derived loop spaces (Toën and Vezzosi,Chern character, loop spaces and derived algebraic geometry, inAlgebraic topology: the Abel symposium 2007, Abel Symposia, vol. 4, eds N. Baas, E. M. Friedlander, B. Jahren and P. A. Østvær (Springer, 2009), ISBN:978-3-642-01199-3) and de Rham theory. IfAis a smooth commutativek-algebra andkhas characteristic 0, we show that two objects,S1⊗Aand ϵ(A), determine one another, functorially inA. The objectS1⊗Ais theS1-equivariant simplicialk-algebra obtained by tensoringAby the simplicial groupS1:=Bℤ, while the object ϵ(A) is the de Rham algebra ofA, endowed with the de Rham differential, and viewed as aϵ-dg-algebra(see the main text). We define an equivalence φ between the homotopy theory of simplicial commutativeS1-equivariantk-algebras and the homotopy theory of ϵ-dg-algebras, and we show the existence of a functorial equivalence ϕ(S1⊗A)∼ϵ(A) . We deduce from this the comparison mentioned above, identifying theS1-equivariant functions on the derived loop spaceLXof a smoothk-schemeXwith the algebraic de Rham cohomology of X/k. As corollaries, we obtainfunctorialandmultiplicativeversions of decomposition theorems for Hochschild homology (in the spirit of Hochschild–Kostant–Rosenberg) for arbitrary semi-separatedk-schemes. By construction, these decompositions aremoreovercompatible with theS1-action on the Hochschild complex, on one hand, and with the de Rham differential, on the other hand.
Cell 2-representations of finitary 2-categories
Authors: Mazorchuk Volodymyr , Miemietz Vanessa 
Published: July 2011

AbstractWe study 2-representations of finitary 2-categories with involution and adjunctions by functors on module categories over finite-dimensional algebras. In particular, we define, construct and describe in detail (right) cell 2-representations inspired by Kazhdan–Lusztig cell modules for Hecke algebras. Under some natural assumptions we show that cell 2-representations are strongly simple and do not depend on the choice of a right cell inside a two-sided cell. This reproves and extends the uniqueness result on categorification of Kazhdan–Lusztig cell modules for Hecke algebras of type A from [V. Mazorchuk and C. Stroppel, Categorification of (induced) cell modules and the rough structure of generalised Verma modules, Adv. Math. 219 (2008), 1363–1426].
Extremely efficient and deterministic approach to generating optimal ordering of diffusion MRI measurements
Authors: Koay Cheng Guan , Hurley Samuel A. , Meyerand M. Elizabeth 
Published: July 2011

Purpose:Diffusion MRI measurements are typically acquired sequentially with unit gradient directions that are distributed uniformly on the unit sphere. The ordering of the gradient directions has significant effect on the quality of dMRI‐derived quantities. Even though several methods have been proposed to generate optimal orderings of gradient directions, these methods are not widely used in clinical studies because of the two major problems. The first problem is that the existing methods for generating highly uniform and antipodally symmetric gradient directions are inefficient. The second problem is that the existing methods for generating optimal orderings of gradient directions are also highly inefficient. In this work, the authors propose two extremely efficient and deterministic methods to solve these two problems.Methods:The method for generating nearly uniform point set on the unit sphere (with antipodal symmetry) is based upon the notion that the spacing between two consecutive points on the same latitude should be equal to the spacing between two consecutive latitudes. The method for generating optimal ordering of diffusion gradient directions is based on the idea that each subset of incremental sample size, which is derived from the prescribed and full set of gradient directions, must be as uniform as possible in terms of the modified electrostatic energy designed for antipodally symmetric point set.Results:The proposed method outperformed the state‐of‐the‐art method in terms of computational efficiency by about six orders of magnitude.Conclusions:Two extremely efficient and deterministic methods have been developed for solving the problem of optimal ordering of diffusion gradient directions. The proposed strategy is also applicable to optimal view‐ordering in three‐dimensional radial MRI.
An investigation into the effects of smoking on physical fitness parameters in adolescents
Authors: Saxena Shobhit , McBean Douglas 
Published: July 2011

Smoking is associated both prognostically and aetiologically with numerous diseases of the respiratory system. Tobacco smoking is a major cause of an accelerated decline in ventilatory function and physical fitness. As most of the people take to smoking when they are young, it will be informative to study the effects of smoking on lungs in the initial stages. The aims of this study were to investigate the effects of smoking on forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and maximal oxygen consumption (VO2max) in adolescent smokers.MethodsAn experimental study subject design was carried out on 15 smoking and 15 non-smoking volunteers within the age group of 18–30 years who were recruited from the college campus. The non-smokers formed the control group. All the subjects underwent spirometric analysis and maximal treadmill test (Bruce protocol) for the estimation of VO2max. Appropriate statistical tests were performed to study the effects 30 min after smoking a cigarette.ResultsThere was a statistically significant difference in the mean spirometric values of FVC/FEV1of the smokers and the non-smokers; however, there was no statistically significant difference in the mean VO2max value in smokers and non-smokers. There was a statistically significant difference in the mean FVC/FEV1of the smokers before and 30 min after smoking a cigarette. Again there was no statistically significant difference in the mean VO2max values before and after smoking a cigarette in the smokers.ConclusionCigarette smoking does have a significant effect on the spirometric values of FVC/FEV1; however, its effect on the maximal oxygen consumption (VO2max) could not be ascertained accurately in adolescent smokers.
Measurement precision: it does matter where you take the skinfolds
Authors: Marfell-Jones Michael J , Hume Patria 
Published: July 2011

IntroductionFor an assessment to have value, it must measure the parameter of interest and be reliable enough to detect small differences. To minimise TEM differences between repeat skinfold measures, measurement sites and measurement techniques have been defined by the International Society for the Advancement of Kinanthropometry (ISAK). The aim of this study, therefore, was to examine the significance of accurate skinfold measurement site location in order to confirm or relax the specific protocols that ISAK has defined.MethodsNine measurements, in a 1-cm grid pattern, centred on each of the eight ISAK-specified skinfold sites, were taken three times at each grid point by each of the two ISAK criteria (level 4) measurers using Harpenden skinfold callipers, on 12 healthy participants (11 males and 1 female; 27.1 ± 6.5 years; 177.3 ± 7.4 cm; 77.8 ± 12.7 kg).ResultsSkinfolds taken at the eight peripheral grid points were generally different (45 out of 64 = 70%) from the skinfolds taken at the central ISAK grid point. The effect was multidirectional. The subscapular was the most robust site in terms of least effect with deviation away from the central point. All other skinfold sites showed some variation with most care needed in marking the biceps and triceps sites.Discussion/conclusionMeasuring 1 cm away from a defined ISAK site produced significant differences in the majority of skinfold measurement values obtained. No site was totally free from this variation. Therefore, adherence to identifying, marking and measuring at the defined site is essential.
A comparative study on body composition of male and female national level sub-junior volleyball players
Authors: Mridha Sanjib 
Published: July 2011

IntroductionBody composition is an important aspect of health for every individual. It influences sport performance to a great extent. There is almost no difference in body composition of males and females in the early childhood but as they advance in age that differences becomes insidious. The purpose of this study was to compare the body composition of male and female national level sub-junior volleyball players.MethodsMale (N = 67) and female (N = 42) sub-junior that is, under 17 years (U-17), volleyball players from six states of India were the subjects of this study. Body composition of the two groups were understood by height, weight, body mass index (BMI), percentage body fat (BF%), fat mass (FM), lean body mass (LBM) and waist-to-hip ratio (WHR). Data of each variable of male and female groups were compared (independent t test) and the level of significance was set at p <0.05 level.ResultsSignificant difference between the two groups was observed in height, weight, BF%, FM, LBM and WHR. Male group was superior in height, weight, LBM and WHR, and female group was superior in BF% and FM than the other group. No difference was observed in BMI of the two groups. Thus the study was concluded as, except BMI, there was difference in body composition of male and female national level sub-junior volleyball players. Female group tend to have greater adiposity than male group and the male group was superior in other body composition variables.
Effect of cocoa supplementation on athlete's blood coagulation factors after an incremental exhaustive exercise
Authors: Soleimani Mehdey , Aghaei Fariba , Atashak Sirvan , Mehdivand Ayub 
Published: July 2011

Cardiovascular disease (CVD) is the main indicator of cardiac arrests and mortality (Willoughby and Holmes 2002).Disruption of the normal rheological properties of blood is considered an independent risk factor for CVD (Douglas and Hein 1998). Platelets play an important role in the pathophysiology of CVD and its associated risk factors (El-sayed 2005). In addition, current evidence implicates fibrinogen (Fib) in the pathogenesis of atherosclerotic vascular diseases and as an independent cardiovascular risk factor (Lars 2003). Also, haemoglobin (Hb) and haematocrit (Htc) factors have the key and important role in whole blood viscosity (El-sayed 2005). Habitual, regular physical activity has been postulated to reduce the incidence of CVD (Johansson and Sundquist 1999). However, high intensity exercise may precipitate acute cardiac events and sudden cardiac death through an occlusive platelet-rich thrombus (Bartsch 1999). However, it has been shown that flavanol-rich foods, such as cocoa promote health and attenuate, or delay the onset of CVD (Murphy 2003). The present study designed to evaluate if cocoa attenuate the effect of an incremental exhaustive exercise on platelet count (Plt), Fib, Hb and Htc. Twenty athlete (football player) male (mean age: 22±1.3 years; body mass: 71.1±4.5 kg; BF%: 22.5±1.2; VO2max: 54.6±2.4 ml/kg/min) provided written informed consent. Bruce exercise test was performed as an incremental exhaustive protocol on two occasions, 1 week apart. In a double-blind design, each participant received either a volume of cocoa solution or flavoured solution based on his body mass before exercise trial. Venous blood samples were collected 2-h prior to exercise (baseline), pre-, post- and 1-h after completion of each trial. Differences were examined using a two-factor analysis of variance with repeated measures as appropriate. Platelet counts, Fib, Hb and Htc decreased significantly (p<0.001) after exercise compared with before exercise in cocoa trials (Plt: from 280.30±31.20 to 206.00±21.13; Fib: from 231±2.20 to 200±1.13; Hb: from 16.80±0.58 to 14.36±1.22; Htc: from 49.60±1.97 to 44.36±2.42). Fib were unaffected by condition and did not differ at any time after exercise protocol (p>0.05).This study showed that increased platelet activity in response to an incremental exercise could be decreased with oral supplementation of cocoa that is line with Murphyet al(2003) and Reinet al(2000). In addition, very little is known about cocoa and it's effecting on Fib, Hb and Htc levels. However, the findings showed that cocoa supplementation decreased Fib, Hb and Htc levels. In conclusion, short-term cocoa supplementation decreased blood coagulation in response to an incremental exhaustive exercise.
The effect of different levels of contextual interference on learning of volleyball passes
Authors: Karimian Maryam , Kashefolhagh Fateme , Dadashi Mohammad Sadegh , Chharbaghi Zahra 
Published: July 2011

IntroductionThe purpose of the present study was to investigate the effect of different levels of contextual interference on the learning of volleyball pass.MethodSixty novice students (age range: 22–24) that were participated voluntarily, according to their records in 10 pretest trails and depend on locale doing pass assigned into four group involve: blocked practice; little contextual interference; medium contextual interference; high contextual interference. The stage of acquisition involves three practice sessions and any session were 10 blocks and any block involving 10 trails. Participants on the blocked practice pass only from one point but another groups (depend on levels contextual interference) pass from different points. Participants then participate in retention and transfer test after a week without practice.ResultsResults indicated that there is a significant interaction between levels of contextual interference and performance. The participants of blocked practice were meaningfully better from another group in acquisition stage but the participants of high and medium contextual interference were meaningfully better from participants of blocked practice in retention and transfer tests.
Constraints of Indian women participation in games and sports
Authors: Rao Nalluri Srinivasa 
Published: July 2011

‘Women in Sport’ has been a topic virtually ignored by most scholars and thus female sport participation has been a relatively undeveloped area of research. Sex role, stereotyping, male research bias and the reward structure of society have contributed to this neglect. Currently, sport for women represents a fast growing changing element in Indian culture, and recent trends have sparked a need for knowledge about the female sport participation.Statement of the problemThe problem under investigation was a study on the constraints of women participation in sports in India. The constraints referred to in the problem stated above will be confined to the study of parental, community, tradition, religion, college and personal constraints of women participation in sports in India.Significance of the StudyThis study has brought to light some new facts regarding women's non-participation in games and sports. The results may go a long way in removing some of these prejudices, thus, some hidden talents of women will be helpful to improve the level of participation and achievement at the national and international level.PopulationThe population under this study was college women who were studying Pre-Degree, Degree and PG Colleges in the Arts, Science and Professional Colleges in India.SampleThousand women of 25 colleges were selected from 12 states in India on a random sampling basis. They were the subjects for the present study and they were selected from selected states in India.ConclusionThere has been lack of encouragement from the parents and family members.The traditional way of living was a big hurdle for women taking part in games and sports.There was lack of sports orientation of the people living in the society. Taking part in games and sports for women has not been become a common phenomenon.There had not been a good leadership among physical education personnel and a proper motivating system.It has been clearly found that government college women had expressed more constraints compared to private college women.
Role of incentive marks in women's sports participation
Authors: Nandurkar P B , Nandurkar P P , Petkar H J 
Published: July 2011

In our Pride India, percentage ratio of men and women is 52.48 and percentage ratio for the literacy among the men and women is 70 and 48, respectively. Woman play vital role in development of India. Hence she should get the representation in all area like education, employment and sports. But even after the 62 years of the independence, women are still deprived in this male dominant culture and her participation is very negligible in sports. Even considering the ratio of men and women at Olympic it is 58:42. Also the numbers of games which are dedicated to men is more that the games that has been played by women. Even at local level like school level or intercollegiate level, women's participation in sports is very less as compare to men. The reasons for this less participation could be (1) less % of literacy, (2) male dominant culture, (3) family and social level abstraction, (4) less availability of women coach, (5) no independent games facilities for women, (6) child marriage, (7) low health conscience, (8) more emphasis on study, (9) cut through competition in education, (10) more emphasis on tuition classes, (11) less importance to sports at society level, (12) lack of government plans for sports person and (13) lack of incentive marks.It has been observed constantly that instead of overall development of students, parents are after the merit and percentage of their child. Now it is necessary to inculcate the feeling that the sport is also a part of education and plays vital role in life of individual. Especially for 10th class percentage, parents start the tuition classes from 9th class, from 9th to 12th std, the students become completely busy in tuition as well as in study, at the age of 15th, 16th, 17th and 18th and these students remain physically unfit due to lack of participation in sports. Even in girl students, the attraction towards the games and sports would be decreased due to this academic competitive environment. If one wants to be a good sports person then he/she needs to practice constantly 3–4 h daily for 4–5 years. But the view to look towards these facts are negative. Most of the parents think that only a single certificate would be the gain out of all these efforts. Instead of that it would be more prestigious to be a rank holder. Especially for the girl students, it is necessary to come forward and increase their participation in sports and games. Hence to increase the participation through the academic encouragement, the incentive marks can be enmarked in their mark statement. For the district level participation, 3 marks; for securing 1st, 2nd, 3rd position, 5 marks; for the state level participation, 10 marks; for securing 1st, 2nd, 3rd position, 15 marks, etc. If sports marks are allotted according to the level of participation then participation can be increased and in future it can be a good scenario in sports.
Effects of yoga on anxiety and depression in women
Authors: Rahimi Eskandar , Bavaqar Sosan 
Published: July 2011

PurposeThe purpose of this study was to examine the influence of yoga on anxiety and depression in Shirazian women. Anxiety and depression are illnesses that increasing in incidence worldwide. They have a profound effect on an individual's physical, emotional, mental and spiritual capacities. It seems that alternative medical systems such as yoga practice can be used for these disorders.MethodThirty-four Shirazian women age 34± volunteer participated in this study and were divided randomly in two control and experimental groups. Exercise protocol included 16 sessions Hata Yoga in the experimental group was carried out. The two training sessions a week and each session 90 M were performed. DASS questionnaire was used to assess anxiety and depression.ResultsOverall findings showed that anxiety and depression significant difference between pretest and post-test experimental group. Also, test anxiety and depression between the experimental and control groups at p <0.05 was a significant difference.ConclusionThe principle aim of this study was investigating the effect of Hata Yoga practices on anxiety and depression. Anxiety and depression are illnesses which are increasing in incidence worldwide, have a profound effect on an individual's physical, emotional, mental and spiritual capacities, and affect the community as a whole because of reduction persons, ability to perform. Not only does a person's ability to enjoy life decrease, but their ability to work, to fulfil their roles as spouse or parent, and to contribute to their community become impaired. As the result of this study and other similar studies yoga practice has benefits for the management of the symptoms of these illnesses, and can create balance in the physical, emotional, mental and spiritual capacities of individuals, so it can be used as alternative health practice to prevent depression and anxiety.