bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wrench capabilities of planar parallel manipulators. Part I: Wrench polytopes and performance indices
Authors: Firmani Flavio , Zibil Alp , Nokleby Scott B. , Podhorodeski Ron P. 
Published: April 2008

SUMMARYThis paper is organized in two parts. In Part I, the wrench polytope concept is presented and wrench performance indices are introduced for planar parallel manipulators (PPMs). In Part II, the concept of wrench capabilities is extended to redundant manipulators and the wrench workspace of different PPMs is analyzed. The end-effector of a PPM is subject to the interaction of forces and moments. Wrench capabilities represent the maximum forces and moments that can be applied or sustained by the manipulator. The wrench capabilities of PPMs are determined by a linear mapping of the actuator output capabilities from the joint space to the task space. The analysis is based upon properly adjusting the actuator outputs to their extreme capabilities. The linear mapping results in a wrench polytope. It is shown that for non-redundant PPMs, one actuator output capability constrains the maximum wrench that can be applied (or sustained) with a plane in the wrench space yielding a facet of the polytope. Herein, the determination of wrench performance indices is presented without the expensive task of generating polytopes. Six study cases are presented and performance indices are derived for each study case.
Internet-Based Self-Help Training for Children and Adolescents with Recurrent Headache: A Pilot Study
Authors: Trautmann Ellen , Kröner-Herwig Birgit 
Published: April 2008

AbstractWe report the results of a randomized controlled trial that compared the efficacy of an internet-based self-help treatment for paediatric headache including chat communication (cognitive-behavioural treatment, CBT) with an internet-based psychoeducation intervention (EDU). In the CBT group, significant pre- to post-treatment decreases were found for headache frequency and pain catastrophizing, but not for headache intensity or duration. In the EDU group none of the variables (frequency, intensity, duration, pain catastrophizing) showed improvement. No significant between group differences were found for headache variables and pain catastrophizing at post-treatment. The patients reported high satisfaction with the internet-based training and a good patient-trainer-alliance. Results were maintained at 6-month follow-up. Due to the small sample size, no general conclusions can be drawn regarding the efficacy of the internet-based training regarding the outcome variables, but the training was well accepted by patients. Further research is necessary to evaluate the therapeutic potential of such interventions.
Association of BMI and nutritional habits with hypertension in the adult population of Croatia
Authors: Uhernik Ana Ivičević , Erceg Marijan , Milanović Sanja Musić 
Published: April 2008

AbstractObjectiveThe purpose of the present study was to investigate the distribution of hypertension, its nutritional and other determinants and their association in Croatia.DesignPopulation-based, cross-sectional study.SettingCroatia.SubjectsRepresentative random sample of 9070 adults (18 years and older) from all Croatian regions, selected using multistage sampling.ResultsOverall prevalence of hypertension (arterial blood pressure ≥140/90 mmHg) in Croatia was 45·5 %, of which 40 % were newly diagnosed hypertensives. There was no difference in the percentage of hypertensives between the continental and Mediterranean parts of Croatia. Newly diagnosed hypertension was found to be positively associated with increased BMI, age and alcohol consumption in the total sample and with moderate consumption of coffee in women, as well as inversely associated with regular consumption of fruits and vegetables in the total sample and high consumption of coffee in the total sample and in men. No association with newly diagnosed hypertension was recorded for use of animal fat, consumption of whole milk, smoked meat products, for adding salt, smoking and leisure-time physical activity.ConclusionsHypertension is a major public health problem in both continental and Mediterranean parts of Croatia. Maintenance of normal body mass, its reduction if already increased, and regular consumption of fruits and vegetables are proposed as priorities for primary prevention of hypertension in Croatia.
AGU Mass Media Fellow Discovers “Wow” Factor
Authors: Larson Ben 
Published: April 2008

I clearly remember the first time I realized that something was amiss with my perception of science.It was the summer of 2001. I was a second‐year graduate student studying hydrothermal chemistry at the University of Washington, in Seattle. At the moment of my realization, I was in New York exploring an exhibit about hydrothermal vents at the American Museum of Natural History. As I was inspecting an intricate diorama of a remotely operated vehicle diving on a vent field, my younger brother, fascinated by the setup, asked, “How come when you talk about this stuff, it always sounds so complicated and boring?” I didn't have a good answer.
Promoting Space Weather Studies in Eastern Europe and Western Asia
Authors: Crosby Norma B. , Babayev Elchin S. 
Published: April 2008

A regional network and an international refereed scientific journal have been established to promote space weather studies in southeastern and east central Europe and in the Caucasus region. The main impetus behind establishing the Balkan, Black Sea, and Caspian Sea Regional Network on Space Weather Studies is to strengthen activities in the region in the field of space science—especially space weather‐related studies—under the umbrella of the International Heliophysical Year (IHY).The network promotes bilateral and multilateral joint projects and collaborations among network countries; the training of young scientists from network countries at participating institutions; and the organizing of annual regional summer/winter schools and colloquia on solar‐terrestrial physics and network meetings in different network countries. In addition, the network promotes activities to popularize the knowledge of solar‐terrestrial physics through network member‐written popular scientific articles published on the network's Web site and in other network country publications. The network also promotes school competitions for proposals for joint/collaborative astrophysical observations. It also promotes “astronomy olympiads,” a competition to test young people on their knowledge of astronomy that remains popular in former Soviet block countries.
Hominin Environments in the East African Pliocene: An Assessment of the Faunal Evidence
Authors: Ruddiman William 
Published: April 2008

This volume grew out of two workshops (Tempe, Ariz., in 2003, and Washington, D.C., in 2004) that brought together scientists who have explored the East African environmental context during the millions of years in which hominins—including our ancestors—evolved. The community of people doing this kind of work is relatively small, in part because it requires long intervals of walking under a tropical Sun looking for outcrops that contain suitable numbers of fossils.Few sites are excavated because the density of fossil remains in undisturbed sedimentary rock is usually too low to make such an effort worthwhile. Nature comes to the fossil hunter's aid by concentrating bones in sites favored by erosion. The most promising of these sites are then explored by surface grid surveys that carefully document the overall context in which the fossils occur, in order to determine the physical (sedimentary), geochemical, and biotic processes that left the deposits. In the end, this meticulous work yields vital clues to critical questions: When and where did our species evolve? And how?
Six‐Month Treatment of Obesity with Sibutramine 15 mg; A Double‐Blind, Placebo‐Controlled Monocenter Clinical Trial in a Hispanic Population
Authors: Cuellar Guillermina Elisa Martínez , Ruiz Alberto Martínez , Monsalve Maria Cristina Revilla , Berber Arturo 
Published: April 2008

AbstractObjective: To evaluate the safety and efficacy of sibutramine 15 mg by mouth once per day in obese patients over a period of 6 months.Research Methods and Procedures: A monocenter, double‐blind, placebo controlled, parallel, prospective clinical trial was carried out. Sixty‐nine male and female obese patients (body mass index [BMI] > 30 kg/m2) aged 16 to 65 years entered the trial.Results: 22 of 35 patients in the sibutramine group and 9 of 34 patients in the placebo group completed the trial. The high dropout rate in the sibutramine group was due to adverse events in 3 cases, lack of efficacy (as judged by patients) in 7, loss to follow‐up in 2, and an orthopedic device being worn in 1; in the placebo group the dropouts were ascribed to lack of efficacy (as judged by patients) in 17 cases and to loss to follow‐up in 8 cases. Using the method of last observation carried forward, the weight loss in the sibutramine group was 10.27 kg (95% confidence intervals [95% CI] 7.66; 13.07) and 1.26 kg (95% CI 0.3; 2.23) in the placebo group. The BMI loss was 4.17 kg/m2 (95% CI 3.11; 5.22) in the sibutramine group and 0.53 kg/m2 (95% CI 0.13; 0.92) in the placebo group. The waist circumference reduction was 12.51 cm (95% CI 9.25; 15.77) in the sibutramine group and 3.26 cm (95% CI 1.38; 5.14) in the control group (p < 0.05 by paired Student's t test for all the intragroup comparisons). Twenty‐three sibutramine patients had 34 adverse events, the most frequent adverse events in the sibutramine group were upper respiratory tract infections (n = 6) and constipation (n = 6); 16 placebo patients had 21 adverse events. Three sibutramine patients withdrew their informed consent when they had adverse events.Discussion: The results show that sibutramine induces significant loss of body weight and waist circumference. Cardiovascular function was not significantly affected by sibutramine. Sibutramine was well tolerated by most of the patients.
The Expression of Peroxisome Proliferator‐Activated Receptor γ in Pig Fetal Tissue and Primary Stromal‐Vascular Cultures
Authors: Kim Hyun‐Sook , Hausman Gary J. , Hausman Dorothy B. , Martin Roy J. , Dean Roger G. 
Published: April 2008

AbstractObjective: This study was designed to determine when peroxisome proliferator‐activated receptor γ (PPARγ) is expressed in developing fetal adipose tissue and stromal‐vascular adipose precursor cells derived from adipose tissue. In addition we examined developing tissue for CCAAT/enhancer‐binding protein β (C/EBPβ) expression to see if it was correlated with PPARγ expression. Pituitary function and hormones involved with differentiation (dexamethasone and retinoic acid) were also tested for their effects on PPARγ expression to determine if hormones known to affect differentiation also effect PPARγ expression in vivo and in cell culture.Research Methods and Procedures: Developing subcutaneous adipose tissues from the dorsal region of the fetal pig were collected at different gestation times and assayed using Western blot analysis to determine levels of PPARγ and C/EBPβ. Hypophysectomy was performed on 75‐day pig fetuses and tissue samples were then taken at 105 days for Western blot analysis. Adipose tissue was also taken from postnatal pigs to isolate stromal‐vascular (S‐V) cells. These adipose precursor cells were grown in culture and samples were taken for Western blot analysis to determine expression levels of PPARγ.Results: Our results indicate that PPARγ is expressed as early as 50 days of fetal development in adipose tissue and continues through 105 days. Expression of PPARγ was found to be significantly enhanced in adipose tissue from hypophysectomized fetuses at 105 days of fetal development (p < 0.05). C/EBPβ was not found in 50‐ or 75‐day fetal tissues and was found only at low levels in 105‐day tissues. C/EBPβ was not found in hypophysectomized (hypoxed) 105‐day tissue where PPARγ was elevated. S‐V cells freshly isolated from adipose tissue of 5‐ to 7‐day postnatal pigs showed the expression of PPARγ1. When S‐V cells were cultured, both PPARγ1 and 2 were expressed after the first day and continued as cells differentiated. High concentrations of retinoic acid decreased PPARγ expression in early S‐V cultures (p < 0.05).Discussion: Our data indicate that PPARγ is expressed in fetal adipose tissue very early before distinct fat cells are observed and can be expressed without the expression of C/EBPβ. The increase in PPARγ expression after hypophysectomy may explain the increase in fat cell size under these conditions. Adipose precursor cells (S‐V cells) from 5‐ to 7‐day postnatal pigs also express PPARγ in the tissue before being induced to differentiate in culture. Thus S‐V cells from newborn pig adipose tissue are probably more advanced in development than the 3T3‐L1 cell model. S‐V cells may be in a state where PPARγ and C/EBPα are expressed but new signals or vascularization are needed before cells are fully committed and lipid filling begins.
Obesity and Physical and Emotional Well‐Being: Associations between Body Mass Index, Chronic Illness, and the Physical and Mental Components of the SF‐36 Questionnaire
Authors: Doll Helen A. , Petersen Sophie E. K. , Stewart‐Brown Sarah L. 
Published: April 2008

AbstractObjective: To clarify the associations between obesity and health‐related quality of life by exploring the associations between physical and emotional well‐being in relation to obesity and the presence of other chronic illness.Research Methods and Procedures: The study data were collected as part of a postal‐survey within the old Oxford Regional Health Authority of England in 1997. Completed questionnaires were returned by 8889 of 13,800 randomly selected adults aged 18 to 64 years. The main outcome measures were body mass index in five categories (underweight, normal weight, overweight, moderately obese, morbidly obese); chronic illness status (any vs. none and number of such illnesses 0, 1 to 2, 3+); and mean SF‐36 questionnaire score in two summary component measures reflecting physical and emotional well‐being.Results: Of the subjects, 31% were overweight and an additional 11% were obese. Body mass index was significantly associated with health status, but the pattern varied according to whether the measure reflected physical or emotional well‐being. Physical, but not emotional, well‐being deteriorated markedly with increasing degree of overweight and was limited in subjects who were obese but had no other chronic condition; subjects with chronic illnesses other than obesity were compromised in both dimensions. In terms of the number of chronic illnesses reported, the additional presence of obesity was associated with a significant deterioration in physical but not emotional well‐being.Discussion: Overweight and obesity are associated with poor levels of subjective health status, particularly in terms of physical well‐being. The limitations in emotional well‐being that are reported here and in other studies may be a result of confounding by the presence of accompanying chronic illness.
Prevalence of Pre‐obesity and Obesity in Urban Adult Mexicans in Comparison with Other Large Surveys
Authors: Arroyo Pedro , Loria Alvar , Fernández Victoria , Flegal Katherine M. , Kuri‐Morales Pablo , Olaiz Gustavo , Tapia‐Conyer Roberto 
Published: April 2008

AbstractObjective: 1. To estimate the prevalence of pre‐obesity and obesity in a 1992 to 1993 national survey of the Mexican urban adult population. 2. To compare our findings with other national surveys and with data for Mexican Americans.Research Methods and Procedures: The national representative sample of the Mexican urban adult population included 8462 women and 5929 men aged 20 to 69 years from 417 towns of >2500 people. Body mass index (BMI), calculated from measured weight and height, was classified using the World Health Organization categories of underweight (BMI < 18.5 kg/m2), normal weight (BMI 18.5 to 24.9 kg/m2), pre‐obesity (PreOB = BMI 25 to 29.9 kg/m2) and obesity (OB = BMI 30+ kg/m2). Estimates for Mexican Americans were calculated from U.S. survey data.Results: Overall, 38% of the Mexican urban adult population were classified as pre‐obese and 21% as obese. Men had a higher prevalence of pre‐obesity than women did at all ages, but women had higher values of obesity. Both pre‐obesity and obesity increased with age up to the age range brackets of 40 to 49 or 50 to 59 years for both men and women. Both pre‐obesity and obesity prevalence estimates were remarkably similar to data for Mexican Americans from 1982 through 1984. Comparison with other large surveys showed that countries differed more in the prevalence of obesity than of pre‐obesity, leading to differences in the PreOB/OB ratio, and that countries also differed in the gender ratio (female/male) for both pre‐obesity and obesity.Discussion: Pre‐obesity and obesity were high in our population and increased with age. Our approach of characterizing large surveys by PreOB/OB and gender ratios appeared promising.
Familial Risk of Overweight and Obesity in the Canadian Population using the WHO/NIH Criteria
Authors: Katzmarzyk Peter T. , Pérusse Louis , Rao D. C. , Bouchard Claude 
Published: April 2008

AbstractObjective: To determine the familial risk of overweight and obesity in Canada.Research Methods and Procedures: The sample was comprised of 15,245 participants from 6377 families of the Canada Fitness Survey. The risk of overweight and obesity among spouses and first‐degree relatives of individuals classified as underweight, normal weight, pre‐obese, or obese (Class I and II) according to the WHO/NIH guidelines for body mass index (BMI) was determined using standardized risk ratios.Results: Spouses and first‐degree relatives of underweight individuals have a lower risk of overweight and obesity than the general population. On the other hand, the risk of Class I and Class II obesity (BMI 35 to 39.9 kg/m2) in relatives of Class I obese (BMI 30 to 34.9 kg/m2) individuals was 1.84 (95% CI: 1.27, 2.37) and 1.97 (95% CI: 0.67, 3.25), respectively, in spouses, and 1.44 (95% CI:1.10, 1.78) and 2.05 (95% CI: 1.37, 2.73), respectively in first‐degree relatives. Further, the risk of Class II obesity in spouses and first‐degree relatives of Class II obese individuals was 2.59 (95% CI: −0.91, 6.09) and 7.07 (95% CI: 1.48, 12.66) times the general population risk, respectively.Discussion: There is significant familial risk of overweight and obesity in the Canadian population using the BMI as an indicator. Comparison of risks among spouses and first‐degree relatives suggests that genetic factors may play a role in obesity at more extreme levels (Class II obese) more so than in moderate obesity.
Free Fatty Acids Are Involved in the Inverse Relationship between Hormone‐Sensitive Lipase (HSL) Activity and Expression in Adipose Tissue after High‐Fat Feeding or β3‐Adrenergic Stimulation
Authors: Berraondo Beatriz , Martínez J. Alfredo 
Published: April 2008

AbstractObjective: The hormone‐sensitive lipase (HSL) is the rate‐limiting enzyme in adipose tissue lipolysis. The aim of this experimental trial was to study the effects of a β3‐adrenergic agonist (Trecadrine) on plasma fatty acids, adipocyte HSL activity, and gene expression in control and cafeteria‐induced obese animals.Research Methods and Procedures: Control and cafeteria‐fed rats were treated with a placebo or Trecadrine during 35 days. Plasma fatty acids were measured by an enzymatic method, whereas HSL activity was assessed by using labeled triolein as substrate. Finally, HSL gene expression from white adipose tissue (WAT) was determined using a reverse transcription‐polymerase chain reaction method.Results: Trecadrine administration reduced plasma fatty acids and HSL mRNA levels in abdominal WAT, whereas HSL activity was significantly higher in the Trecadrine‐treated obese rats than in the obese nontreated rats. Also, abdominal WAT HSL activity significantly increased, whereas WAT HSL gene expression fell in control rats treated with β3‐adrenergic agonist as compared with control untreated animals.Discussion: In situations of fat accumulation (high‐fat feeding) or lipid mobilization (β3‐adrenergic stimulation), changes in HSL activity and HSL gene expression seem to follow a trend related to plasma fatty acids levels, as indicated by the positive correlation (r = 0.39, p < 0.05) between HSL mRNA levels and plasma fatty acids, and the negative correlation (r = −0.38, p < 0.05) between plasma fatty acids and HSL activity. Furthermore, a highly negative correlation (r = −0.59, p < 0.001) between HSL activity and HSL mRNA expression was found, in which plasma‐free fatty acids are apparently involved.
Prevalence of Sleep Apnea and Electrocardiographic Disturbances in Morbidly Obese Patients
Authors: Valencia‐Flores Matilde , Orea Arturo , Castaño Violeta A. , Resendiz Montserrat , Rosales María , Rebollar Verónica , Santiago Victoria , Gallegos José , Campos Rosa M. , González Jorge , Oseguera Jorge , García‐Ramos Guillermo , Bliwise Donald L. 
Published: April 2008

AbstractObjective: To determine the prevalence of sleep apnea in morbidly obese patients and its relationship with cardiac arrhythmias.Research Methods and Procedures: Fifty‐two consecutive morbidly obese (body mass index ≥ 40 kg/m2) outpatients from the Obesity Clinic of the National Institute of Nutrition Salvador Zubirán underwent two nights of polysomnography with standard laboratory techniques. Electrocardiographic polysomnography signals (Lead II) were evaluated by two experienced cardiologists, and sleep complaints were measured with a standard sleep questionnaire (Sleep Disorders Questionnaire). In order to make comparisons between groups with different severities of sleep‐disordered breathing, we classified the patients in four groups using the apnea‐hypopnea index (AHI): Group 1, AHI 5 < 15 (n = 10); Group 2, AHI 15 < 30 (n = 10); Group 3, AHI 30 < 65 (n = 14); Group 4, AHI ≥ 65 (n = 17).Results: A wide range of sleep‐disordered breathing, ranging from AHI of 2.5 to 128.9 was found. Ninety‐eight percent of the sample (n = 51) had an AHI ≥ 5 (mean = 51 ± 37), and 33% had severe sleep apnea with AHI ≥ 65 with a mean nocturnal desaturation time of <65% over 135 minutes. Electrocardiographic abnormalities were present in 31% of the patients. Cardiac rhythm alterations showed an association with the level of sleep‐disordered breathing and oxygen desaturation.Discussion: We conclude that there is a high prevalence of sleep apnea in morbidly obese patients and that the risk for cardiac arrhythmias increases in this population in the presence of a severe sleep apnea (AHI ≥ 65) with severe oxygen desaturation (Sao2 ≤ 65%).