Are Autistic Traits in the General Population Related to Global and Regional Brain Differences?
Koolschijn, P. Cédric M. P.; Geurts, Hilde M.; van der Leij, Andries R.; Scholte, H. Steven
2015-01-01
There is accumulating evidence that autistic-related traits in the general population lie on a continuum, with autism spectrum disorders representing the extreme end of this distribution. Here, we tested the hypothesis of a possible relationship between autistic traits and brain morphometry in the general population. Participants completed the…
Differences in social relations between persons with type 2 diabetes and the general population
DEFF Research Database (Denmark)
Hempler, Nana Folmann; Ekholm, Ola; Willaing, Ingrid
2013-01-01
with type 2 diabetes. The aim of this study was to investigate whether persons with type 2 diabetes have poorer social relations than the general population. Methods: We conducted a cross-sectional survey in three settings: a specialist diabetes clinic (SDC) (n = 1084), a web panel (WP) consisting.......08-1.41). Conclusions: Our findings suggest that persons with type 2 diabetes have poorer social relations than the general population. From a public health point of view, special attention is needed with regards to strengthening existing networks and establishing alternative networks among persons with type 2 diabetes.......Aims: Poor social support and lack of social network are well-established risk factors for morbidity and mortality in general populations. Good social relations, such as social support and network contacts, are associated with better self-management and fewer psychosocial problems in persons...
Aging-related trajectories of lung function in the general population-The Doetinchem Cohort Study.
van Oostrom, Sandra H; Engelfriet, Peter M; Verschuren, W M Monique; Schipper, Maarten; Wouters, Inge M; Boezen, Marike; Smit, Henriëtte A; Kerstjens, Huib A M; Picavet, H Susan J
2018-01-01
The objective of this study was to explore trajectories of lung function decline with age in the general population, and to study the effect of sociodemographic and life style related risk factors, in particular smoking and BMI. For this purpose, we used data from the Doetinchem Cohort Study (DCS)
International Nuclear Information System (INIS)
Kenyon, I.R.
1990-01-01
General relativity is discussed in this book at a level appropriate to undergraduate students of physics and astronomy. It describes concepts and experimental results, and provides a succinct account of the formalism. A brief review of special relativity is followed by a discussion of the equivalence principle and its implications. Other topics covered include the concepts of curvature and the Schwarzschild metric, test of the general theory, black holes and their properties, gravitational radiation and methods for its detection, the impact of general relativity on cosmology, and the continuing search for a quantum theory of gravity. (author)
Differences in social relations between persons with type 2 diabetes and the general population.
Hempler, Nana Folmann; Ekholm, Ola; Willaing, Ingrid
2013-06-01
Poor social support and lack of social network are well-established risk factors for morbidity and mortality in general populations. Good social relations, such as social support and network contacts, are associated with better self-management and fewer psychosocial problems in persons with type 2 diabetes. The aim of this study was to investigate whether persons with type 2 diabetes have poorer social relations than the general population. We conducted a cross-sectional survey in three settings: a specialist diabetes clinic (SDC) (n = 1084), a web panel (WP) consisting of persons with type 2 diabetes (n = 1491) and a sample from the 2010 Danish Health and Morbidity Survey, representative of the general population (n = 15,165). We compared social relations using multivariate logistic regression. Compared to the general population, persons with type 2 diabetes more often lived without a partner (SDC, OR 1.75, 95% CI 1.49-2.06; WP, OR 1.64, 95% CI 1.43-1.87), met with family less than once a month (SDC, OR 1.78, 95% CI 1.40-2.27; WP, OR 2.35, 95% CI 1.94-2.84) and were less certain they could count on help from others in case of illness (WP, OR 1.23, 95% CI 1.08-1.41). Our findings suggest that persons with type 2 diabetes have poorer social relations than the general population. From a public health point of view, special attention is needed with regards to strengthening existing networks and establishing alternative networks among persons with type 2 diabetes.
Kim, Young Ae; Yun, Young Ho; Chang, Yoon Jung; Lee, Jongmog; Kim, Moon Soo; Lee, Hyun-Sung; Zo, Jae Ill; Kim, Jhingook; Choi, Yong Soo; Shim, Young Mog; Yoon, Seok-Jun
2014-03-01
To investigate the employment status of lung cancer survivors and the work-related problems they face. Although the number of lung cancer survivors is increasing, little is known about their employment and work-related issues. We enrolled 830 lung cancer survivors 12 months after lung cancer curative surgery (median time after diagnosis, 4.11 years) and 1000 volunteers from the general population. All participants completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Core 30-item and a questionnaire that included items relating to their jobs. We used logistic regression analysis to identify independent predictors of unemployment. The employment rate of lung cancer survivors decreased from 68.6% at the time of diagnosis to 38.8% after treatment, which was significantly lower than the employment rate of the general population (63.5%; adjusted odds ratio = 2.31, 95% confidence interval: 1.66-3.22). The posttreatment unemployment rate was higher for women than for men. Among survivors, employment was inversely associated with older age, household income, number of comorbidities, and poor social functioning. Fatigue (78.6%) was the most common work-related problem reported by survivors. Lung cancer survivors experienced more difficulties in employment than did the general population. Age, monthly household income, number of comorbidities, and social functioning appear to be important factors influencing employment status. These findings suggest that lung cancer survivors need support to cope with the financial impact of cancer.
Straumann, Norbert
2013-01-01
This book provides a completely revised and expanded version of the previous classic edition ‘General Relativity and Relativistic Astrophysics’. In Part I the foundations of general relativity are thoroughly developed, while Part II is devoted to tests of general relativity and many of its applications. Binary pulsars – our best laboratories for general relativity – are studied in considerable detail. An introduction to gravitational lensing theory is included as well, so as to make the current literature on the subject accessible to readers. Considerable attention is devoted to the study of compact objects, especially to black holes. This includes a detailed derivation of the Kerr solution, Israel’s proof of his uniqueness theorem, and a derivation of the basic laws of black hole physics. Part II ends with Witten’s proof of the positive energy theorem, which is presented in detail, together with the required tools on spin structures and spinor analysis. In Part III, all of the differential geomet...
International Nuclear Information System (INIS)
Gourgoulhon, Eric
2013-01-01
The author proposes a course on general relativity. He first presents a geometrical framework by addressing, presenting and discussion the following notions: the relativistic space-time, the metric tensor, Universe lines, observers, principle of equivalence and geodesics. In the next part, he addresses gravitational fields with spherical symmetry: presentation of the Schwarzschild metrics, radial light geodesics, gravitational spectral shift (Einstein effect), orbitals of material objects, photon trajectories. The next parts address the Einstein equation, black holes, gravitational waves, and cosmological solutions. Appendices propose a discussion of the relationship between relativity and GPS, some problems and their solutions, and Sage codes
A General Method for QTL Mapping in Multiple Related Populations Derived from Multiple Parents
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Yan AO
2009-03-01
Full Text Available It's well known that incorporating some existing populations derived from multiple parents may improve QTL mapping and QTL-based breeding programs. However, no general maximum likelihood method has been available for this strategy. Based on the QTL mapping in multiple related populations derived from two parents, a maximum likelihood estimation method was proposed, which can incorporate several populations derived from three or more parents and also can be used to handle different mating designs. Taking a circle design as an example, we conducted simulation studies to study the effect of QTL heritability and sample size upon the proposed method. The results showed that under the same heritability, enhanced power of QTL detection and more precise and accurate estimation of parameters could be obtained when three F2 populations were jointly analyzed, compared with the joint analysis of any two F2 populations. Higher heritability, especially with larger sample sizes, would increase the ability of QTL detection and improve the estimation of parameters. Potential advantages of the method are as follows: firstly, the existing results of QTL mapping in single population can be compared and integrated with each other with the proposed method, therefore the ability of QTL detection and precision of QTL mapping can be improved. Secondly, owing to multiple alleles in multiple parents, the method can exploit gene resource more adequately, which will lay an important genetic groundwork for plant improvement.
Age-related differences in internalizing psychopathology amongst the Australian general population.
Sunderland, Matthew; Slade, Tim; Carragher, Natacha; Batterham, Philip; Buchan, Heather
2013-11-01
Two methodological criticisms have limited the reliability and validity of findings from previous studies that seek to examine change across the life span in levels of internalizing psychopathology using general population surveys. The first criticism involves the potential influence of cohort effects that confound true age-related changes whereas the second criticism involves the use of a single form of assessment to measure and compare levels of internalizing psychopathology. This study seeks to address these criticisms by modeling age-related change using multiple measures and multiple surveys. Data from 2 epidemiological surveys conducted 10 years apart in the Australian general population were combined and used for the current study. The latent construct of internalizing psychopathology was modeled using a combination of Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) depression and anxiety diagnoses as well as items from the Kessler Psychological Distress scale (K10; Kessler et al., 2002). Confirmatory factor analysis (CFA) indicated that a single internalizing dimension provided good model fit to the data. Multigroup CFA indicated that strict measurement invariance of the model can be assumed across survey administrations and age bands, justifying comparisons of mean differences in latent trait levels. Significant changes in mean levels of latent internalizing psychopathology were evident between respondents aged 30-39 years old in 1997 and respondents aged 40-49 years old in 2007, suggesting a minor but significant increase in psychopathology across middle age. By contrast, a minor but significant decrease in psychopathology was noted when transitioning from late middle age (50-59 years old) to old age (60-69 years old). The majority of individuals in the general population will experience constant levels of internalizing psychopathology as they age, suggesting that the construct is relatively
Energy Technology Data Exchange (ETDEWEB)
Yang, Jae-Ho; Kim, Sun-Young; Shin, Im-Hee [Catholic Univ. of Daegu, School of Medicine, Dept. of Pharmacology/Toxicology, Daegu (Korea); Kannan, K. [Wardsworth Center, New York State Dept. of Health and Dept. of Env. Health and Tox., SUNY, Albany, NY (United States)
2004-09-15
Perfluorooctanesulfonate (PFOS) was found to be widespread in human populations and wildlife Major applications of these POSF-based products have included surfactants in: specialty paper and packaging products, carpet, upholstery, and textile products and in certain insecticide formulation. Depending on the specific functional derivatization or the degree of polymerization, such POSF based products may degrade or metabolize to PFOS, a stable and persistent end product that has the potential to bioaccumulate in the food chain. The mechanisms and pathways leading to the presence of PFOS in human blood are not well characterized but likely involve environmental and dietary exposure to PFOS or to precursor molecules of PFOS. PFOS and related perfluorinated compounds have recently been detected at low parts per billion (nanogram per milliliter) concentrations in the general population from 10 different countries including Korea. In the present report, the levels of perfluoroalkylated compounds in the general population from Korea were analyzed with respect to occupation, smoking status, sex, age and socio-economic status. The degree of association between the four target fluorochemicals measured in this study (PFOS, PFHxS, PFOA, and PFOSA) were also analyzed by linear regression to determine the potential association between their sources of exposure.
Rodríguez-Míguez, Eva; Mosquera Nogueira, Jacinto
To estimate the intangible effects of alcohol misuse on the drinker's quality of life, based on general population preferences METHODS: The most important effects (dimensions) were identified by means of two focus groups conducted with patients and specialists. The levels of these dimensions were combined to yield different scenarios. A sample of 300 people taken from the general Spanish population evaluated a subset of these scenarios, selected by using a fractional factorial design. We used the probability lottery equivalent method to derive the utility score for the evaluated scenarios, and the random-effects regression model to estimate the relative importance of each dimension and to derive the utility score for the rest of scenarios not directly evaluated. Four main dimensions were identified (family, physical health, psychological health and social) and divided into three levels of intensity. We found a wide variation in the utilities associated with the scenarios directly evaluated (ranging from 0.09 to 0.78). The dimensions with the greatest relative importance were physical health (36.4%) and family consequences (31.3%), followed by psychological (20.5%) and social consequences (11.8%). Our findings confirm the benefits of adopting a heterogeneous approach to measure the effects of alcohol misuse. The estimated utilities could have both clinical and economic applications. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
Sources of dietary protein in relation to blood pressure in a general Dutch population.
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Wieke Altorf-van der Kuil
Full Text Available BACKGROUND: Little is known about the relation of different dietary protein types with blood pressure (BP. We examined whether intake of total, plant, animal, dairy, meat, and grain protein was related to BP in a cross sectional cohort of 20,820 Dutch adults, aged 20-65 y and not using antihypertensive medication. DESIGN: Mean BP levels were calculated in quintiles of energy-adjusted protein with adjustment for age, sex, BMI, education, smoking, and intake of energy, alcohol, and other nutrients including protein from other sources. In addition, mean BP difference after substitution of 3 en% carbohydrates or MUFA with protein was calculated. RESULTS: Total protein and animal protein were not associated with BP (p(trend = 0.62 and 0.71 respectively, both at the expense of carbohydrates and MUFA. Systolic BP was 1.8 mmHg lower (p(trend36 g/d than in the lowest (<27 g/d quintile of plant protein. This inverse association was present both at the expense of carbohydrates and MUFA and more pronounced in individuals with untreated hypertension (-3.6 mmHg than in those with normal (+0.1 mmHg or prehypertensive BP (-0.3 mmHg; p(interaction<0.01. Meat and grain protein were not related to BP. Dairy protein was directly associated with systolic BP (+1.6 mmHg, p(trend<0.01, but not with diastolic BP (p(trend = 0.24. CONCLUSIONS: Total protein and animal protein were not associated with BP in this general untreated Dutch population. Plant protein may be beneficial to BP, especially in people with elevated BP. However, because high intake of plant protein may be a marker of a healthy diet and lifestyle in general, confirmation from randomized controlled trials is warranted.
Gender-related dimensions of childhood adversities in the general population.
Coêlho, Bruno M; Santana, Geilson L; Viana, Maria C; Andrade, Laura H; Wang, Yuan-Pang
2018-06-11
Childhood adversities (CAs) comprise a group of negative experiences individuals may suffer in their lifetimes. The goal of the present study was to investigate the cluster discrimination of CAs through psychometric determination of the common attributes of such experiences for men and women. Parental mental illness, substance misuse, criminality, death, divorce, other parental loss, family violence, physical abuse, sexual abuse, neglect, physical illness, and economic adversity were assessed in a general-population sample (n=5,037). Exploratory and confirmatory factor analysis determined gender-related dimensions of CA. The contribution of each individual adversity was explored through Rasch analysis. Adversities were reported by 53.6% of the sample. A three-factor model of CA dimensions fit the data better for men, and a two-factor model for women. For both genders, the dimension of family maladjustment - encompassing physical abuse, neglect, parental mental disorders, and family violence - was the core cluster of CAs. Women endorsed more CAs than men. Rasch analysis found that sexual abuse, physical illness, parental criminal behavior, parental divorce, and economic adversity were difficult to report in face-to-face interviews. CAs embrace sensitive personal information, clustering of which differed by gender. Acknowledging CAs may have an impact on medical and psychiatric outcomes in adulthood.
Gender-related dimensions of childhood adversities in the general population
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Bruno M. Coêlho
2018-06-01
Full Text Available Objective: Childhood adversities (CAs comprise a group of negative experiences individuals may suffer in their lifetimes. The goal of the present study was to investigate the cluster discrimination of CAs through psychometric determination of the common attributes of such experiences for men and women. Methods: Parental mental illness, substance misuse, criminality, death, divorce, other parental loss, family violence, physical abuse, sexual abuse, neglect, physical illness, and economic adversity were assessed in a general-population sample (n=5,037. Exploratory and confirmatory factor analysis determined gender-related dimensions of CA. The contribution of each individual adversity was explored through Rasch analysis. Results: Adversities were reported by 53.6% of the sample. A three-factor model of CA dimensions fit the data better for men, and a two-factor model for women. For both genders, the dimension of family maladjustment – encompassing physical abuse, neglect, parental mental disorders, and family violence – was the core cluster of CAs. Women endorsed more CAs than men. Rasch analysis found that sexual abuse, physical illness, parental criminal behavior, parental divorce, and economic adversity were difficult to report in face-to-face interviews. Conclusion: CAs embrace sensitive personal information, clustering of which differed by gender. Acknowledging CAs may have an impact on medical and psychiatric outcomes in adulthood.
Age-related changes in abdominal fat distribution in Japanese adults in the general population.
Sugihara, Masako; Oka, Rie; Sakurai, Masaru; Nakamura, Koshi; Moriuchi, Tadashi; Miyamoto, Susumu; Takeda, Yoshiyu; Yagi, Kunimasa; Yamagishi, Masakazu
2011-01-01
Early studies have indicated that body fat shifts from peripheral stores to central stores with aging. The objective of this study was to investigate age-related changes in abdominal fat distribution of Japanese men and women of the general population over a wide range of body mass indices (BMI). A total of 2,220 non-diabetic, apparently healthy Japanese adults (1,240 men and 980 women; age range 40-69 years) were included in the study sample. All subjects underwent a CT scan at the level of the umbilicus, and the areas of visceral adipose tissue (AT) and subcutaneous AT were quantified. When the subjects were stratified by BMI into 18.5-23.0 kg/m(2), 23.0-27.5 kg/m(2), and 27.5 kg/m(2) or higher, visceral AT was positively correlated with age in all of the BMI strata in both genders (pabdominal fat distribution, women retained the subcutaneous-dominant type of fat distribution up to 70 years.
Holvoet, Lien; Huys, Wim; Coppens, Violette; Seeuws, Jantien; Goethals, Kris; Morrens, Manuel
2017-01-01
Abstract: Background Bondage and discipline, dominance and submission, and sadism and masochism (BDSM) is gaining popularity through the mainstream media. Nevertheless, very little is known about the prevalence of BDSM-related fantasies and activities in the general population. Aim To determine the prevalence of BDSM fantasies and behavioral involvement in four different age groups of the general population in Belgium. Methods By use of a cross-sectional survey questionnaire, the level of int...
Lukács, Liza; Murányi, István; Túry, Ferenc
2007-02-01
Pathological eating attitudes and extreme weight control practices occur most commonly in certain female populations. In some young male occupation groups, such as in the armed forces, the appearance of physical strength and muscularity has particular importance. We studied body and eating attitudes and the prevalence of bodybuilding and steroid abuse in 480 military college and 752 general college male students. The Eating Disorder Inventory was used for all subjects. General college students had higher body mass index values than did military students. The prevalence of bodybuilding and steroid abuse was significantly greater in the military population. Comparisons between the study groups and within groups showed significantly different scores on certain Eating Disorder Inventory subscales. The study revealed that male military college students have some protective factors against the psychopathological features of eating disorders.
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Völzke Henry
2006-02-01
Full Text Available Abstract Background Little is known about proportions of smokers who maintain smoking after they are aware of a circulatory disorder. The goal was to analyze the extent to which the number of circulatory disorders may be related to being a current smoker. Methods Cross-sectional survey study with a probability sample of residents in Germany investigated in health examination centers. Questionnaire data of 3,778 ever smoking participants aged 18 – 79 were used, questions included whether the respondent had ever had hypertension, myocardial infarction, other coronary artery disease, heart failure, stroke, other cerebrovascular disease, peripheral vascular disease, and venous thrombosis. Logistic regression was calculated for circulatory disorders and their number with current smoking as the dependent variable, and odds ratios (OR are presented adjusted for physician contact, inpatient treatment, smoking cessation counseling, heavy smoking, exercise, overweight and obesity, school education, sex and age. Results Among ever smokers who had 1 circulatory disorder, 52.1 % were current smokers and among those who reported that they had 3 or more circulatory disorders 28.0 % were current smokers at the time of the interview. The adjusted odds of being a current smoker were lower for individuals who had ever smoked in life and had 2 or more central circulatory disorders, such as myocardial infarction, heart failure or stroke, than for ever smokers without central circulatory disorder (2 or more disorders: adjusted OR 0.6, 95 % confidence interval, CI, 0.4 to 0.8. Conclusion Among those with central circulatory disorders, there is a substantial portion of individuals who smoke despite their disease. The data suggest that only a portion of smokers among the general population seems to be discouraged from smoking by circulatory disorders or its accompanying cognitive or emotional processes.
The Relation of Moderate Alcohol Consumption to Hyperuricemia in a Rural General Population
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Zhao Li
2016-07-01
Full Text Available Background: although alcohol abuse is known to increase serum uric acid, the relation between moderate drinking and uric acid have remained poorly understood. We performed this study to evaluate whether different alcohol consumption level has different effects on the risk of hyperuricemia based on a rural general population. Method: multi-stage cluster sampling method was used to select a representative sample of individuals aged 35 years or older. Participants were asked to provide information about their alcohol consumption. Data regarding the demographic and lifestyle characteristics and the blood biochemical indexes of these participants were collected by well-trained personnel. Results: in total, 11,039 participants aged 35 years or older were included (4997 men and 6042 women. The prevalence of hyperuricemia in the different male alcohol consumption groups was 11.9% in non-drinkers, 12.6% in moderate drinkers, and 16.3% in heavy drinkers (p < 0.001. In females, the rates were 6.3% in non-drinkers, 8.1% in moderate drinkers, and 6.6% for heavy drinkers (p = 0.818. In males, multivariate logistic regression analyses shows heavy drinkers had an approximately 1.7-fold higher risk of hyperuricemia (OR: 1.657, 95% CI: 1.368 to 2.007, p < 0.001 than non-drinkers; moderate drinkers did not experience a significant increase in risk (OR: 1.232, 95% CI: 0.951 to 1.596, p = 0.114. Multivariate logistic regression analyses of females showed that, compared with non-drinkers, neither moderate nor heavy drinkers had a significantly increased risk of hyperuricemia (OR: 1.565, 95% CI: 0.521 to 4.695, p = 0.425 for heavy drinkers; OR: 0.897, 95% CI: 0.117 to 6.855, p = 0.916 for moderate drinkers. Conclusions: heavy alcohol consumption increased the risk of hyperuricemia for males but not for females. Among both males and females, moderate alcohol consumption did not increase the risk of hyperuricemia.
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Alireza Khosravi
2010-12-01
Full Text Available Abstract BACKGROUND: Enhancement of albumin exertion in urine increases the risk of renal and ischemic heart diseases (IHD. We assessed the association of urine albumin and sub-clinical IHD in a random sample of Iranian general population. METHODS: The random sample in general population in Isfahan County was recruited to the cross-sectional study. From the all sample blood pressure and lipid profile were assessed and morning urine spot was measured for albumin and Creatinine. Microalbuminuria was defined either Albumin-Creatinine Ratio (ACR was 30-300mg. Also, the standard 12 lead electrocardiogram (ECG was carried out for all participants. The ECG pattern was divided to two categories; normal or ECG with ischemia. The logistic regression model was determined the odds of albuminuria for ischemic changes in ECG. RESULTS: 999 subjects, age 35-70 years, participated to study. From all, 40.8% were male. Microalbuminuria was detected in 8% and sub-clinical ECG ischemic changes were found in 23.4%. The most frequent ischemic change was T wave inversion. The mean urine albumin levels in subjects with normal ECG was 9.6±14.6 mg/ml and in ischemic group was 8.5±12.2 mg/ml and they did not have statistically different. The odds ratios of neither Albumin-Creatinine ratio nor microalbuminuria were in significant range for risk to ischemic changes in ECG of apparently healthy participants. They was consecutively OR=0.9 (0.51-1.6, OR=0.99 (0.98-1.004. CONCLUSION: Our finding didn’t declare any association between ACR and IHD. Because of showing this association in the other study; it needs more exploration regarding to association between microalbuminuria and cardiovascular diseases incidence. Keywords: Ischemic heart diseases, electrocardiogram, Albumin-Creatinine Ratio, Urine Albumin
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Juliana dos Santos Müller
2016-05-01
Full Text Available Quality of life is an indicator of how well one perceives that he/she is functioning physically and mentally. The aim of this paper is to determine the health-related quality of life (HRQOL of artisanal fisherwomen/shellfish gatherers from the Saubara municipality in Bahia, Brazil in comparison to the general population. A structured questionnaire was administered to a sample of 209 artisanal fisherwomen selected at random. The HRQOL questionnaire, known as the 36-Item Short-Form Health Survey version 1 (SF-36v01, was also used, having been translated and verified cross-culturally for the Brazilian population. Sociodemographic, lifestyle and comorbidity information was also collected. Chronic diseases and indicators of musculoskeletal disorders (MSDs were self-reported. The study population consisted primarily of individuals between 30 and 45 years of age (78%, of self-classified races black or brown (96.2%, with no more than an elementary school education (77% and married (64.6%. In all the SF-36v01 dimensions, the values in the sample were lower than in the general population of Brazil, which was used as the reference population. In the “Physical Health” domain (Physical Functioning; Physical Role Limitations; Bodily Pain; General Health Perception a tendency toward a lower health-related quality of life was observed among those who were older, had a lower education level, and had a prevalence of MSDs, hypertension or arthritis. The interference of health conditions linked to the fisherwomen’s work activities may contribute to lower HRQOL in all analyzed aspects, in comparison to the general population. In light of these findings, public health policies must consider these informal workers who contribute greatly to Brazil’s economy and food system.
Holvoet, Lien; Huys, Wim; Coppens, Violette; Seeuws, Jantien; Goethals, Kris; Morrens, Manuel
2017-09-01
Bondage and discipline, dominance and submission, and sadism and masochism (BDSM) is gaining popularity through the mainstream media. Nevertheless, very little is known about the prevalence of BDSM-related fantasies and activities in the general population. To determine the prevalence of BDSM fantasies and behavioral involvement in four different age groups of the general population in Belgium. By use of a cross-sectional survey questionnaire, the level of interest in several BDSM-related activities was investigated in a sample representative of the general Belgian population (N = 1,027). The questionnaire evaluated interest in 54 BDSM activities and 14 fetishes. Self-identification as BDSM practitioner, situational context of BDSM practice, age at awareness of these interests, and transparency to others were queried. Individual item scores and summary scores on four BDSM categories were included in the analyses. A high interest in BDSM-related activities in the general population was found because 46.8% of the total sample had ever performed at least one BDSM-related activity and an additional 22% indicated having (had) fantasies about it. Interestingly, 12.5% of the total population indicated performing at least one BDSM-related activity on a regular basis. When asked whether they saw themselves as being interested in BDSM, 26% stated this to be the case and 7.6% self-identified as BDSM practitioners. Interests in dominant and submissive activities were comparable and, remarkably, were highly intercorrelated. BDSM and fetish interests were significantly higher in men than in women. The older group (48-65 years) had significantly lower BDSM scores compared with their younger peers. Of participants with a BDSM interest, 61.4% became aware of it before 25 years of age. There is a high level of interest in BDSM in the general population, which strongly argues against stigmatization and pathologic characterization of these interests. This is the first thorough study
Prevalence of pelvic organ prolapse and related factors in a general female population
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Hakan Aytan
2014-09-01
Full Text Available Objective: The aim of this study was to assess the prevalence and the related factors of pelvic organ prolapse (POP in a female population to whom health care services are offered. Materials and Methods: 1354 of the 3000 women admitted to the outpatient clinic between June 2008 and December 2008 were enrolled as they accepted to participate to the study. 34 of these patients with a history of previous hysterectomy and/or any kind of pelvic reconstructive surgery were excluded. Baseline characteristics, as well as medical and obstetric history of the patients were recorded. All women underwent vaginal examination to determine the degree of prolapse by pelvic organ prolapse quantification (POPQ system. POP-Q stages ≥2 were defined as prolapse. Women with and without prolapse were compared. Regression analysis was used in order to determine the independent predictors. Results: Prolapse (stage ≥2 was detected in 358 patients (27.1%. Patients with prolapse were found to be significantly older and heavier. They had a higher waist to hip ratio and had a higher parity. Compared to women without prolapse, cesarean rate was significantly lower in women with prolapse (10.6% vs. 20.8%; p<0.001, and the mean birth weight of the babies of the women with prolapse was significantly higher (3584±574 vs. 3490±389 g, p=0.004. Prevalence of prolapse was found to be decreased as the level of education increased. Waist to hip ratio (OR: 46.2, CI: 3.3-655, p=0.005, parity (OR: 1.5, CI: 1.3-1.7, p<0.001, vaginal delivery (OR: 1.5, CI: 0.3-0.8, p=0.005, and menopausal status (OR: 1.2, CI: 1.1-1.4, p=0.005 were found to be independent predictors of development of POP. Conclusion: In the present study, POP was found to be associated with waist to hip ratio, parity, vaginal delivery, and menopausal status.
Old persons' contact with general practitioners in relation to health: a Danish population study
DEFF Research Database (Denmark)
Almind, G; Holstein, B E; Holst, E
1991-01-01
The study describes health, social situation, and contact with general practitioners in a random sample of non-institutionalized persons 70-95 years old in Denmark. There was a strong correlation between health and contact with general practitioners. A small group, 3% of the respondents, had...... no health problems, but had been in contact with a general practitioner within the previous month. This group was characterized by a strong social network and a high degree of life satisfaction. Another small group, including 3% of the respondents, had extensive health problems, but had nevertheless...
Zenger, Markus; Hinz, Andreas; Stolzenburg, Jens-Uwe; Rabenalt, Robert; Schwalenberg, Thilo; Schwarz, Reinhold
2009-01-01
The objective of this study was to examine the age-specific health-related quality of life (HRQOL) of prostate cancer patients (PCPs). 387 PCPs were asked to self-assess their HRQOL with the EORTC QLQ-C30 questionnaire. Patients' data were compared with those of the general German population. The reported global health/QOL scores of the study group and the general German population are nearly equal. However, most of the subdomains of HRQOL are negatively affected in PCPs, especially in younger patients (
Heartburn and related factors in general population in Tehran, capital of Iran.
Safaee, A; Moghimi-Dehkordi, B; Pourhoseingholi, M Ap; Habibi, M; Qafarnejad, F; Pourhoseingholi, A; Zali, M R
2010-06-01
Heartburn is a highly prevalent disorder and is one of the most common gastrointestinal (GI) symptoms encountered in clinical practice. Despite the increasing importance of the early diagnosis of heartburn, there are few studies available on the prevalence of the disease and its Symptoms. The aim of this study was to estimate the frequency of heartburn in the Iranian adult population and analyze its associations with possible confounding factors. This study was designed as an epidemiological, cross-sectional and population based study that was conducted during May to December 2006 in Firoozkou city of Iran. Participants were interviewed by using a questionnaire which included sociodemographic, health relevant life style and clinical factors and GI symptoms. Statistical analysis was performed by using chi-square test and logistic regression model. The frequency of heartburn was 28% and is different between men and women (P heartburn in univariate analysis (p heartburn. Heartburn is very frequent in Iranian population and has a considerable impact on everyday life. Many factors that may affect the prevalence of heartburn should be considered for prevention and control of this disease.
Sources of dietary protein in relation to blood pressure in a general Dutch population
Altorf-van der Kuil, W.; Engberink, M.F.; Vedder, M.M.; Boer, J.M.A.; Verschuren, W.M.M.; Geleijnse, J.M.
2012-01-01
Background - Little is known about the relation of different dietary protein types with blood pressure (BP). We examined whether intake of total, plant, animal, dairy, meat, and grain protein was related to BP in a cross sectional cohort of 20,820 Dutch adults, aged 20–65 y and not using
Directory of Open Access Journals (Sweden)
Le Qihua
2012-07-01
Full Text Available Abstract Background Dry eye syndrome (DES is a common ocular disorder occurring in general population. The purpose of this study is to evaluate the impact of DES on vision-related quality of life (QoL in a non-clinic-based general population. Methods This population-based cross-sectional study enrolled subjects older than 40 years, who took part in an epidemiological study on dry eye in Sanle Community, Shanghai. Apart from the collection of sociodemographics, dry eye symptoms, and other clinical data, a Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25 was administered to all subjects. Comparisons of the NEI VFQ-25 subscale item scores and composite score were made among subgroups divided according to the presence of dry eye symptoms or signs. Multivariate regression analysis was performed to investigate the relationship between the clinical variables and the VFQ-25 composite score. Results A total of 229 participants were enrolled in the study, with an average age of (60.7 ±10.1 years old. Majority of these participants were female (59.8 %, 137/229. The total DES symptom scores (TDSS in subjects either with definite DES or only with dry eye symptoms were significantly higher (F = 60.331, P Conclusions The symptoms of dry eye are associated with an adverse impact on vision-related QoL in non-clinic-based general population, which is mainly represented as more ocular pain and discomfort, and impaired mental health as well. Apart from clinical examination, it is also important to refer to subjective symptoms and QoL scores when assessing the severity of DES.
Visible Age-Related Signs and Risk of Ischemic Heart Disease in the General Population
DEFF Research Database (Denmark)
Christoffersen, Mette; Frikke-Schmidt, Ruth; Schnohr, Peter
2014-01-01
developed MI. Presence of frontoparietal baldness, crown top baldness, earlobe crease, and xanthelasmata was associated with increased risk of IHD or MI after multifactorial adjustment for chronological age and well-known cardiovascular risk factors. The risk of IHD and MI increased stepwise with increasing...... risk of IHD and MI increased with increasing number of visible age-related signs. CONCLUSIONS: Male pattern baldness, earlobe crease, and xanthelasmata-alone or in combination-associate with increased risk of ischemic heart disease and myocardial infarction independent of chronological age and other...
Oral manifestations of stress-related disorders in the general population of Ludhiana
Directory of Open Access Journals (Sweden)
Damanpreet Kaur
2016-01-01
Full Text Available Introduction: Oral diseases associated with psychological disorders have long been known in medicine. Emotional as well as psychological factors may act as significant risk factors in the initiation and progression of oromucosal diseases. Aims and Objectives: The aim of this study was to determine a correlation between stress and development of certain oral conditions such as lichen planus, myofacial pain dysfunction syndrome, xerostomia, bruxism, aphthous ulcers, and burning mouth syndrome. Materials and Methods: An observational comparative study was conducted among patients reporting to the Department of Oral Medicine and Radiology. A total of 130 patients gave a positive history of oral lesions, out of which 62 were stress related and the other 68 patients served as the control group (oral lesions with no history of stress. All these patients were subjected to routine systemic and oral examination. The results obtained were statistically compared using P value, t-test, and Chi-square test. Results: It was found that lichen planus and burning mouth syndrome were more common in females and myofacial pain dysfunction syndrome was prevalent in males. Xerostomia was found to increase with age. Conclusion: It was concluded that, though the etiology of most oral lesions is not known, the role of stress and other psychogenic factors cannot be ruled out in their occurrence.
Engelen, Lucien JLPG; Berben, Sivera AA; Teerenstra, Steven; Samsom, Melvin; Schoonhoven, Lisette
2013-01-01
Background Health care is increasingly featured by the use of Web 2.0 communication and collaborative technologies that are reshaping the way patients and professionals interact. These technologies or tools can be used for a variety of purposes: to instantly debate issues, discover news, analyze research, network with peers, crowd-source information, seek support, and provide advice. Not all tools are implemented successfully; in many cases, the nonusage attrition rates are high. Little is known about the preferences of the Dutch general population regarding the use of the Internet and social media in health care. Objective To determine the preferences of the general population in the Netherlands regarding the use of the Internet and social media in health care. Methods A cross-sectional survey was disseminated via a popular Dutch online social network. Respondents were asked where they searched for health-related information, how they qualified the value of different sources, and their preferences regarding online communication with health care providers. Results were weighed for the Dutch population based on gender, age, and level of education using official statistics. Numbers and percentages or means and standard deviations were presented for different subgroups. One-way ANOVA was used to test for statistical differences. Results The survey was completed by 635 respondents. The Internet was found to be the number one source for health-related information (82.7%), closely followed by information provided by health care professionals (71.1%). Approximately one-third (32.3%) of the Dutch population search for ratings of health care providers. The most popular information topics were side effects of medication (62.5%) and symptoms (59.7%). Approximately one-quarter of the Dutch population prefer to communicate with a health care provider via social media (25.4%), and 21.2% would like to communicate via a webcam. Conclusions The Internet is the main source of health-related
Van de Belt, Tom H; Engelen, Lucien J L P G; Berben, Sivera A A; Teerenstra, Steven; Samsom, Melvin; Schoonhoven, Lisette
2013-10-02
Health care is increasingly featured by the use of Web 2.0 communication and collaborative technologies that are reshaping the way patients and professionals interact. These technologies or tools can be used for a variety of purposes: to instantly debate issues, discover news, analyze research, network with peers, crowd-source information, seek support, and provide advice. Not all tools are implemented successfully; in many cases, the nonusage attrition rates are high. Little is known about the preferences of the Dutch general population regarding the use of the Internet and social media in health care. To determine the preferences of the general population in the Netherlands regarding the use of the Internet and social media in health care. A cross-sectional survey was disseminated via a popular Dutch online social network. Respondents were asked where they searched for health-related information, how they qualified the value of different sources, and their preferences regarding online communication with health care providers. Results were weighed for the Dutch population based on gender, age, and level of education using official statistics. Numbers and percentages or means and standard deviations were presented for different subgroups. One-way ANOVA was used to test for statistical differences. The survey was completed by 635 respondents. The Internet was found to be the number one source for health-related information (82.7%), closely followed by information provided by health care professionals (71.1%). Approximately one-third (32.3%) of the Dutch population search for ratings of health care providers. The most popular information topics were side effects of medication (62.5%) and symptoms (59.7%). Approximately one-quarter of the Dutch population prefer to communicate with a health care provider via social media (25.4%), and 21.2% would like to communicate via a webcam. The Internet is the main source of health-related information for the Dutch population
Subic-Wrana, Claudia; Beutel, Manfred E; Brähler, Elmar; Stöbel-Richter, Yve; Knebel, Achim; Lane, Richard D; Wiltink, Jörg
2014-01-01
The Levels of Emotional Awareness Scale (LEAS) as a performance task discriminates between implicit or subconscious and explicit or conscious levels of emotional awareness. An impaired awareness of one's feeling states may influence emotion regulation strategies and self-reports of negative emotions. To determine this influence, we applied the LEAS and self-report measures for emotion regulation strategies and negative affect in a representative sample of the German general population. A short version of the LEAS, the Hospital Anxiety and Depression Scale (HADS) and the Emotion Regulation Questionnaire (ERQ), assessing reappraisal and suppression as emotion regulation strategies, were presented to N = 2524 participants of a representative German community study. The questionnaire data were analyzed with regard to the level of emotional awareness. LEAS scores were independent from depression, but related to self-reported anxiety. Although of small or medium effect size, different correlational patters between emotion regulation strategies and negative affectivity were related to implict and explict levels of emotional awareness. In participants with implicit emotional awareness, suppression was related to higher anxiety and depression, whereas in participants with explicit emotional awareness, in addition to a positive relationship of suppression and depression, we found a negative relationship of reappraisal to depression. These findings were independent of age. In women high use of suppression and little use of reappraisal were more strongly related to negative affect than in men. Our first findings suggest that conscious awareness of emotions may be a precondition for the use of reappraisal as an adaptive emotion regulation strategy. They encourage further research in the relation between subconsious and conscious emotional awareness and the prefarance of adaptive or maladaptive emotion regulation strategies The correlational trends found in a representative
Dyrbye, Liselotte N; West, Colin P; Satele, Daniel; Boone, Sonja; Tan, Litjen; Sloan, Jeff; Shanafelt, Tait D
2014-03-01
To compare the prevalence of burnout and other forms of distress across career stages and the experiences of trainees and early career (EC) physicians versus those of similarly aged college graduates pursuing other careers. In 2011 and 2012, the authors conducted a national survey of medical students, residents/fellows, and EC physicians (≤ 5 years in practice) and of a probability-based sample of the general U.S. population. All surveys assessed burnout, symptoms of depression and suicidal ideation, quality of life, and fatigue. Response rates were 35.2% (4,402/12,500) for medical students, 22.5% (1,701/7,560) for residents/fellows, and 26.7% (7,288/27,276) for EC physicians. In multivariate models that controlled for relationship status, sex, age, and career stage, being a resident/fellow was associated with increased odds of burnout and being a medical student with increased odds of depressive symptoms, whereas EC physicians had the lowest odds of high fatigue. Compared with the population control samples, medical students, residents/fellows, and EC physicians were more likely to be burned out (all P prevalence of burnout, depressive symptoms, and recent suicidal ideation are relatively small. At each stage, burnout is more prevalent among physicians than among their peers in the U.S. population.
Social-cultural factors of HIV-related stigma among the Chinese general population in Hong Kong.
Yeo, Tien Ee Dominic; Chu, Tsz Hang
2017-10-01
HIV-related stigma in the wider community compounds the suffering of people living with HIV (PLWH) and hampers effective HIV prevention and care. This study examines the level of public stigma toward PLWH in Hong Kong and associated social-cultural factors. A telephone survey was conducted in June-July 2016 with 1080 Chinese adults aged 18-94 randomly selected from the general population. The results indicate substantial degree of public stigma toward PLWH. Overall, 58.1% of the participants endorsed at least one statement indicating negative social judgment of PLWH. Over 40% attributed HIV infections to irresponsible behaviors and nearly 30% perceived most PLWH as promiscuous. About 20% considered HIV to be a punishment for bad behavior and believed that PLWH should feel ashamed of themselves. These statistics indicate that HIV-related stigma among the general Hong Kong population had no noticeable reduction in a decade but is lower than that among rural and urban populations in China. Our findings suggest that the lower stigma in Hong Kong may be linked to higher education levels rather than Hongkongers' more Westernized outlook. The results of a multiple regression analysis showed that education level (β = -.19), homophobia (β = .30), and conformity to norms (β = .14) were independent predictors of HIV-related stigma but not age, income, or cultural orientations. By differentiating between associated social-cultural factors, this study provides a more nuanced understanding of the layered nature of HIV-related stigma: not broadly grounded in religion or Chinese culture but stemming from more specific social-cultural beliefs - perceptions of norm violation and negative attitudes toward homosexuality, which were not mutually exclusive. These findings have implications for HIV-related stigma reduction by providing evidence for the importance of addressing homophobia. Existing HIV publicity activities should be re-examined for inadvertent contribution
Ridgely, Charles T.
2010-01-01
Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…
Theoretical general relativity: 1979
International Nuclear Information System (INIS)
Bergmann, O.
1979-01-01
The metric and field equations of Einstein's general relativity theory are written down. Solutions to the equations are discussed. Connection is made between relativity theory and elementary particle theory. Possibilities for a unified field theory are considered
Bozionelos, Nikos; Bozionelos, Giorgos; Kostopoulos, Konstantinos; Polychroniou, Panagiotis
2011-01-01
Purpose: This study aims to investigate the relationship of mentoring provided with career success and organizational commitment in the general managerial population. Design/methodology/approach: Participants were 194 native British who were employed in a variety of jobs, professions and industries in the United Kingdom. Findings: Mentoring…
Shanafelt, Tait D; Boone, Sonja; Tan, Litjen; Dyrbye, Lotte N; Sotile, Wayne; Satele, Daniel; West, Colin P; Sloan, Jeff; Oreskovich, Michael R
2012-10-08
Despite extensive data about physician burnout, to our knowledge, no national study has evaluated rates of burnout among US physicians, explored differences by specialty, or compared physicians with US workers in other fields. We conducted a national study of burnout in a large sample of US physicians from all specialty disciplines using the American Medical Association Physician Masterfile and surveyed a probability-based sample of the general US population for comparison. Burnout was measured using validated instruments. Satisfaction with work-life balance was explored. Of 27 276 physicians who received an invitation to participate, 7288 (26.7%) completed surveys. When assessed using the Maslach Burnout Inventory, 45.8% of physicians reported at least 1 symptom of burnout. Substantial differences in burnout were observed by specialty, with the highest rates among physicians at the front line of care access (family medicine, general internal medicine, and emergency medicine). Compared with a probability-based sample of 3442 working US adults, physicians were more likely to have symptoms of burnout (37.9% vs 27.8%) and to be dissatisfied with work-life balance (40.2% vs 23.2%) (P < .001 for both). Highest level of education completed also related to burnout in a pooled multivariate analysis adjusted for age, sex, relationship status, and hours worked per week. Compared with high school graduates, individuals with an MD or DO degree were at increased risk for burnout (odds ratio [OR], 1.36; P < .001), whereas individuals with a bachelor's degree (OR, 0.80; P = .048), master's degree (OR, 0.71; P = .01), or professional or doctoral degree other than an MD or DO degree (OR, 0.64; P = .04) were at lower risk for burnout. Burnout is more common among physicians than among other US workers. Physicians in specialties at the front line of care access seem to be at greatest risk.
Li, Dongxue; Guo, Guanghong; Xia, Lili; Yang, Xinghua; Zhang, Biao; Liu, Feng; Ma, Jingang; Hu, Zhiping; Li, Yajun; Li, Wei; Jiang, Jiajia; Gaisano, Herbert; Shan, Guangliang; He, Yan
2018-01-01
Background: Absolute handgrip strength has been correlated with metabolic profile and metabolic disease. Whether relative handgrip strength is also associated with metabolic disease has not been assessed. This study aimed at assessing the association of relative handgrip strength with metabolic profile and metabolic disease in the general population in China. Methods: Data were derived from an ongoing cross-sectional survey of the 2013 National Physical and Health in Shanxi Province, which involved 5520 participants. Multiple linear regression or multiple logistic regression analysis were used to assess the association of absolute/relative handgrip strength with the metabolic profile, preclinical, and established stages of metabolic diseases. Results: This study revealed that relative handgrip strength, that is when normalized to BMI, was associated with: (1) in both genders for more favorable blood lipid levels of high-density lipoprotein cholesterol [males: b = 0.19 (0.15, 0.23); females: b = 0.22 (0.17, 0.28)], low-density lipoprotein cholesterol [males: b = -0.14 (-0.23, -0.05); females: b = -0.19 (-0.31, -0.18)], triglycerides [males: b = -0.58 (-0.74, -0.43); females: b = -0.55 (-0.74, -0.36)] and total cholesterol [males: b = -0.20 (-0.31, -0.10); females: b = -0.19 (-0.32, -0.06)]; and better serum glucose levels in males [ b = -0.30 (-0.46, -0.15)]. (2) lower risk of impaired fasting glucose in males {third quartile [OR = 0.66 (0.45-0.95)] and fourth quartile [OR = 0.46 (0.30-0.71)] vs. first quartile} and dyslipidemia in both genders {third quartile [males: OR = 0.65 (0.48-0.87); females: OR = 0.68 (0.53-0.86)] and fourth quartile [males: OR = 0.47 (0.35-0.64); females: OR = 0.47(0.36-0.61)] vs. first quartile}. (3) lower risk of hyperlipidemia in both genders third quartile [males: OR = 0.66 (0.50-0.87); females: OR = 0.57 (0.43-0.75)] and fourth quartile [males: OR = 0.35 (0.26-0.47); females: OR = 0.51 (0.38-0.70)] vs. first quartile. However, contrary
vanOverbeek, FM; UilDieterman, IGA; Mol, IW; KohlerBrands, L; Heymans, HSA; Mulder, CJJ
1997-01-01
Background: It has been suggested that the amount of gluten intake in populations offers an explanation for differences in the epidemiology of coeliac disease. Investigations into first-degree relatives of coeliac disease patients have often shown that relatives exhibit intermediate features of
Sar, Vedat; Alioğlu, Firdevs; Akyüz, Gamze
2014-01-01
This study sought to determine the prevalence of experiences of possession and paranormal phenomena (PNP) in the general population and their possible relations to each other and to traumatic stress and dissociation. The study was conducted on a representative female sample recruited from a town in central eastern Turkey. The Dissociative Disorders Interview Schedule, the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interviews for DSM-IV Axis-I and Personality Disorders, and the Childhood Abuse and Neglect Questionnaire were administered to 628 women. Of these, 127 (20.2%) women reported at least 1 type of PNP and 13 (2.1%) women reported possession. Women with a dissociative disorder reported all types of possession and PNP (except telepathy) more frequently than those without. Whereas women with a trauma history in childhood and adulthood or PTSD reported possession more frequently than those without, PNP were associated with childhood trauma only. Factor analysis yielded 4 dimensions: possession by and/or contact with nonhuman entities, extrasensory communications, possession by a human entity, and precognition. These factors correlated with number of secondary features of dissociative identity disorder and Schneiderian symptoms. Latent class analysis identified 3 groups. The most traumatized group, with predominantly dissociative and trauma-related disorders, had the highest scores on all factors. Notwithstanding their presence in healthy individuals, possession and PNP were associated with trauma and dissociation in a subgroup of affected participants. Both types of experience seem to be normal human capacities of experiencing that may be involved in response to traumatic stress. Given the small numbers, this study should be considered preliminary.
DEFF Research Database (Denmark)
Hietala, M; Hakonen, A; Aro, A R
1995-01-01
evaluated attitudes toward gene tests in general and also respondents' preparedness to undergo gene tests for predictive testing, carrier detection, prenatal diagnosis, and selective abortion, in theoretical situations. The results of the study indicate that both the Finnish population in general and family...... members of AGU patients have a favorable attitude toward genetic testing. However, a commonly expressed reason against testing was that test results might lead to discrimination in employment or insurance policies. Based on the responses, we predict that future genetic testing programs will most probably...
International Nuclear Information System (INIS)
Rosen, N.
1979-01-01
A modification of general relativity is proposed involving a second metric tensor describing a space-time of constant curvature and associated with the fundamental rest-frame of the universe. The theory generally agrees with the Einstein theory, but gives cosmological models without singularities which can account for present observation, including helium abundance
Jackson, A. T.
1973-01-01
Reviews theoretical and experimental fundamentals of Einstein's theory of general relativity. Indicates that recent development of the theory of the continually expanding universe may lead to revision of the space-time continuum of the finite and unbounded universe. (CC)
General relativity and experiment
Damour, T.
1994-01-01
The confrontation between Einstein's theory of gravitation and experiment is summarized. Although all current experimental data are compatible with general relativity, the importance of pursuing the quest for possible deviations from Einstein's theory is emphasized.
International Nuclear Information System (INIS)
Ridgely, Charles T
2010-01-01
Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.
Directory of Open Access Journals (Sweden)
Dongxue Li
2018-02-01
Full Text Available Background: Absolute handgrip strength has been correlated with metabolic profile and metabolic disease. Whether relative handgrip strength is also associated with metabolic disease has not been assessed. This study aimed at assessing the association of relative handgrip strength with metabolic profile and metabolic disease in the general population in China.Methods: Data were derived from an ongoing cross-sectional survey of the 2013 National Physical and Health in Shanxi Province, which involved 5520 participants. Multiple linear regression or multiple logistic regression analysis were used to assess the association of absolute/relative handgrip strength with the metabolic profile, preclinical, and established stages of metabolic diseases.Results: This study revealed that relative handgrip strength, that is when normalized to BMI, was associated with: (1 in both genders for more favorable blood lipid levels of high-density lipoprotein cholesterol [males: b = 0.19 (0.15, 0.23; females: b = 0.22 (0.17, 0.28], low-density lipoprotein cholesterol [males: b = −0.14 (−0.23, −0.05; females: b = −0.19 (−0.31, −0.18], triglycerides [males: b = −0.58 (−0.74, −0.43; females: b = −0.55 (−0.74, −0.36] and total cholesterol [males: b = −0.20 (−0.31, −0.10; females: b = −0.19 (−0.32, −0.06]; and better serum glucose levels in males [b = −0.30 (−0.46, −0.15]. (2 lower risk of impaired fasting glucose in males {third quartile [OR = 0.66 (0.45–0.95] and fourth quartile [OR = 0.46 (0.30–0.71] vs. first quartile} and dyslipidemia in both genders {third quartile [males: OR = 0.65 (0.48–0.87; females: OR = 0.68 (0.53–0.86] and fourth quartile [males: OR = 0.47 (0.35–0.64; females: OR = 0.47(0.36–0.61] vs. first quartile}. (3 lower risk of hyperlipidemia in both genders third quartile [males: OR = 0.66 (0.50–0.87; females: OR = 0.57 (0.43–0.75] and fourth quartile [males: OR = 0.35 (0.26–0.47; females: OR
Ray, J. R.
1982-01-01
Two theories of matter in general relativity, the fluid theory and the kinetic theory, were studied. Results include: (1) a discussion of various methods of completing the fluid equations; (2) a method of constructing charged general relativistic solutions in kinetic theory; and (3) a proof and discussion of the incompatibility of perfect fluid solutions in anisotropic cosmologies. Interpretations of NASA gravitational experiments using the above mentioned results were started. Two papers were prepared for publications based on this work.
Sharma, Nandini; Anand, Tanu; Grover, Shekhar; Kumar, Arun; Singh, Mongjam M; Ingle, Gopal K
2018-04-02
Almost 40% of Delhi's population lives in slums and is vulnerable to tobacco use. It is therefore important to assess their opinion and ensure compliance to antismoking legislation. The present study was undertaken to assess the awareness of the general public residing in slums in Delhi regarding the smoke-free initiative of 2009, 3 years after intensive implementation. It was a cross-sectional study conducted among participants selected by cluster sampling from the slums in six districts of Delhi using a pretested semistructured questionnaire. A total of 708 slum dwellers were interviewed. Out of the total, only 16.1% (n = 114) of the participants had heard of The Cigarettes and Other Tobacco Products (Prohibition of Advertisement and Regulation of Trade and Commerce, Production, Supply and Distribution) Act, 2003 (COTPA), though, they were aware about some of the provisions of the COTPA. Majority (n = 529; 74.7%) perceived the smoke-free zones as the places where smoking forms of tobacco are banned. Regarding the awareness about the places designated as smoke-free zones, 82.1% (n = 581) of the respondents named educational institutions. About 61% of the people interviewed reported to have seen people smoking at public places on the day of interview while only 21.5% reported to have seen any one getting punished for smoking. Awareness about COTPA was low. The study respondents perceived that no action was being taken against persons acting in violation of the law. Thus, there is a need for stricter implementation of COTPA and increased spreading of awareness among the general public. While awareness about antismoking legislation among general population (particularly slums) has been studied world over, this has not been the case in India. The study depicts opinion of one of the susceptible populations regarding tobacco control legislation, which has hitherto not been studied in the Indian context. This study has an important implication as it highlights the need
International Nuclear Information System (INIS)
Hayashi, K.; Shirafuji, T.
1979-01-01
A gravitational theory is formulated on the Weitzenboeck space-time, characterized by the vanishing curvature tensor (absolute parallelism) and by the torsion tensor formed of four parallel vector fields. This theory is called new general relativity, since Einstein in 1928 first gave its original form. New general relativity has three parameters c 1 , c 2 , and lambda, besides the Einstein constant kappa. In this paper we choose c 1 = 0 = c 2 , leaving open lambda. We prove, among other things, that (i) a static, spherically symmetric gravitational field is given by the Schwarzschild metric, that (ii) in the weak-field approximation an antisymmetric field of zero mass and zero spin exists, besides gravitons, and that (iii) new general relativity agrees with all the experiments so far carried out
Lectures on general relativity
Papapetrou, Achille
1974-01-01
This book is an elaboration of lecture notes for the graduate course on General Rela tivity given by the author at Boston University in the spring semester of 1972. It is an introduction to the subject only, as the time available for the course was limited. The author of an introduction to General Relativity is faced from the beginning with the difficult task of choosing which material to include. A general criterion as sisting in this choice is provided by the didactic character of the book: Those chapters have to be included in priority, which will be most useful to the reader in enabling him to understand the methods used in General Relativity, the results obtained so far and possibly the problems still to be solved. This criterion is not sufficient to ensure a unique choice. General Relativity has developed to such a degree, that it is impossible to include in an introductory textbook of a reasonable length even a very condensed treatment of all important problems which have been discussed unt...
General Relativity and Gravitation
Ehlers, J.; Murdin, P.
2000-11-01
The General Theory of Relativity (GR), created by Albert Einstein between 1907 and 1915, is a theory both of gravitation and of spacetime structure. It is based on the assumption that matter, via its energy-momentum, interacts with the metric of spacetime, which is considered (in contrast to Newtonian physics and SPECIAL RELATIVITY) as a dynamical field having degrees of freedom of its own (GRAVI...
International Nuclear Information System (INIS)
Penrose, R.
1979-01-01
Much theoretical work in General Relativity has been concerned with finding explicit solutions of Einstein field equations. Exact solutions must involve simplifying procedures which in the case of strong gravitational fields may not be valid. Computers can help but complementary to these are the global qualitative mathematics that have been introduced into relativity over the past years. These have shown that Einstein's equations together with suitable inequalities on the energy-momentum tensor can lead inevitably to space-time singularities arising, provided that some qualitative geometric criterion is satisfied. It seems that in suitable situations of gravitational collapse this criterion will be satisfied. Similarly in a cosmological setting the criterion can be applied in the reverse direction in time. There is, however, the unsolved problem in general relativity of cosmic censorship and this is discussed as a consequence of Einstein's equations. (UK)
International Nuclear Information System (INIS)
Clarke, C.
1979-01-01
The plan of the book is as follows: Chapter 1 develops special relativity in a setting and notation that can immediately be transferred to general relativity. Most of the fundamental geometrical ideas are established here. Chapter 2 gives a more conventional account of some selected applications of special relativity. Chapter 3 is the heart of the book. A geometrical model of space-time is progressively built up, motivated by physical arguments stemming from the equivalence principle, leading to Einstein's field equations. Chapter 4 deals very quickly with the simplest form of weak-field theory with application to gravitational radiation. Chapter 5 concludes the book with a fairly detailed analysis of the Schwarzschild solution, plane fronted gravitational waves, and the Robertson-Walker cosmological solutions. Exercises at the end of each chapter extend the general theory into particular applications, giving a broader picture of the scope of the subject. (author)
Drageset, Jorunn; Natvig, Gerd Karin; Eide, Geir Egil; Clipp, Elizabeth C; Bondevik, Margareth; Nortvedt, Monica W; Nygaard, Harald A
2008-05-01
To advance the understanding of health-related quality of life among older nursing home residents by assessing their health-related quality of life and comparing this with norms from the general population. The study used a two-group cross-sectional comparative design. The samples comprised 227 nursing home residents aged 65-102 years with at least six months' residence and a representative population sample of 1137 Norwegian citizens aged 65-102 years. All nursing home residents had a Clinical Dementia Rating Scale score > or =0.5 and were capable of conversing. The respondents provided demographic information and were surveyed using the SF-36 Health Survey. We used univariate and multivariate linear models to identify possible differences in health-related quality of life between the nursing home residents and the general population, controlled for age, sex, marital status and education. After adjustment for age, group, sex, marital status and education, the nursing home residents scored significantly higher on bodily pain and on physical and emotional role limitation and significantly lower on the other SF-36 subscales, except social functioning, with the largest differences for physical functioning (mean nursing home 23.2 and mean general population 62.9). The general population scores on all subscales generally increased with increasing education but not among the nursing home residents. The mean SF-36 scale scores differed markedly between the nursing home residents and the general population, with the nursing home residents generally scoring lower. The association with background variables known to be related to health-related quality of life differed between the groups. Healthcare professionals should increase attention to health-related quality of life among nursing home residents, periodically assess health-related quality of life and consider interventions that may improve health-related quality of life in older institutionalised populations. This study
General Relativity and Gravitation
Ashtekar, Abhay; Berger, Beverly; Isenberg, James; MacCallum, Malcolm
2015-07-01
Part I. Einstein's Triumph: 1. 100 years of general relativity George F. R. Ellis; 2. Was Einstein right? Clifford M. Will; 3. Cosmology David Wands, Misao Sasaki, Eiichiro Komatsu, Roy Maartens and Malcolm A. H. MacCallum; 4. Relativistic astrophysics Peter Schneider, Ramesh Narayan, Jeffrey E. McClintock, Peter Mészáros and Martin J. Rees; Part II. New Window on the Universe: 5. Receiving gravitational waves Beverly K. Berger, Karsten Danzmann, Gabriela Gonzalez, Andrea Lommen, Guido Mueller, Albrecht Rüdiger and William Joseph Weber; 6. Sources of gravitational waves. Theory and observations Alessandra Buonanno and B. S. Sathyaprakash; Part III. Gravity is Geometry, After All: 7. Probing strong field gravity through numerical simulations Frans Pretorius, Matthew W. Choptuik and Luis Lehner; 8. The initial value problem of general relativity and its implications Gregory J. Galloway, Pengzi Miao and Richard Schoen; 9. Global behavior of solutions to Einstein's equations Stefanos Aretakis, James Isenberg, Vincent Moncrief and Igor Rodnianski; Part IV. Beyond Einstein: 10. Quantum fields in curved space-times Stefan Hollands and Robert M. Wald; 11. From general relativity to quantum gravity Abhay Ashtekar, Martin Reuter and Carlo Rovelli; 12. Quantum gravity via unification Henriette Elvang and Gary T. Horowitz.
Yoo, Hyosang; Shin, Dong Wook; Jeong, Ansuk; Kim, So Young; Yang, Hyung-Kook; Kim, Jun Suk; Lee, Ji Eun; Oh, Jae Hwan; Park, Eun-Cheol; Park, Keeho; Park, Jong-Hyock
2017-08-01
It is well known that cancer patients' perception of social support is associated with their depressive symptoms and health-related quality of life. However, there have been little studies that compared the variates of cancer patients with the general population. We sought to compare differences in the level of perceived social support and the impact of perceived social support on depressive symptoms and health-related quality of life between cancer survivors and the general population. Data were collected from 1818 cancer patients treated at the National Cancer Center and regional cancer centers in South Korea. The control group of the general population was composed of 2000 individuals without cancer from community. Cancer patients reported significantly higher level of perceived social support than the general population, while they reported lower health-related quality of life and were more susceptible to depression. The positive associations of higher perceived social support with lower depressive symptoms, as well as with higher health-related quality of life, were stronger among cancer patients than among the general population. The interaction effect suggests that the impact of social support would be stronger among cancer patients than the general public. Thus, it would be beneficial to pay attention to providing social support to cancer patients, particularly to those who are more vulnerable. Furthermore, investigation of the most effective and efficient methods to deliver social support interventions would be worthwhile. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Directory of Open Access Journals (Sweden)
Swaantje Barth
Full Text Available Aims of the study were to investigate health-related quality of life (HRQOL in adult patients with former diagnosis of Juvenile Idiopathic Arthritis (JIA, to compare their HRQOL with the general population and to identify factors related to a poor outcome.In 2012, a cross-sectional survey was performed by mailing a questionnaire to a large cohort of former and current patients of the German Centre for Rheumatology in Children and Adolescents. Only adult patients (≥18 years with a diagnosis compatible with JIA were included (n = 2592; response 66%. The questionnaire included information about HRQOL (EQ5D, disease-related questions and socio-demographics. Prevalence and 95% confidence intervals (CI of problems with mobility, self-care, usual activities, pain and anxiety/depression were standardized to the German general population. Factors associated with low HRQOL in JIA patients were identified using logistic regression models.Sixty-two percent of the study population was female; age range was 18-73 years. In all dimensions, JIA patients reported statistically significantly more problems than the general population with largest differences in the pain dimension (JIA patients 56%; 95%CI 55-58%; general population 28%; 26-29% and the anxiety/depression dimension (28%; 27-29% vs. 4%; 4-5%. Lower HRQOL in JIA patients was associated with female sex, older age, lower level of education, still being under rheumatic treatment and disability.HRQOL in adult JIA patients is considerably lower than in the general population. As this cohort includes historic patients the new therapeutic schemes available today are expected to improve HRQOL in future.
Barth, Swaantje; Haas, Johannes-Peter; Schlichtiger, Jenny; Molz, Johannes; Bisdorff, Betty; Michels, Hartmut; Hügle, Boris; Radon, Katja
2016-01-01
Aims of the study were to investigate health-related quality of life (HRQOL) in adult patients with former diagnosis of Juvenile Idiopathic Arthritis (JIA), to compare their HRQOL with the general population and to identify factors related to a poor outcome. In 2012, a cross-sectional survey was performed by mailing a questionnaire to a large cohort of former and current patients of the German Centre for Rheumatology in Children and Adolescents. Only adult patients (≥18 years) with a diagnosis compatible with JIA were included (n = 2592; response 66%). The questionnaire included information about HRQOL (EQ5D), disease-related questions and socio-demographics. Prevalence and 95% confidence intervals (CI) of problems with mobility, self-care, usual activities, pain and anxiety/depression were standardized to the German general population. Factors associated with low HRQOL in JIA patients were identified using logistic regression models. Sixty-two percent of the study population was female; age range was 18-73 years. In all dimensions, JIA patients reported statistically significantly more problems than the general population with largest differences in the pain dimension (JIA patients 56%; 95%CI 55-58%; general population 28%; 26-29%) and the anxiety/depression dimension (28%; 27-29% vs. 4%; 4-5%). Lower HRQOL in JIA patients was associated with female sex, older age, lower level of education, still being under rheumatic treatment and disability. HRQOL in adult JIA patients is considerably lower than in the general population. As this cohort includes historic patients the new therapeutic schemes available today are expected to improve HRQOL in future.
Sun, Sun; Irestig, Robert; Burström, Bo; Beijer, Ulla; Burström, Kristina
2012-03-01
To describe and compare health-related quality of life (HRQoL) among homeless persons with a general population sample in Stockholm County, 2006, and to analyse the importance of certain social determinants of health among the homeless. Face-to-face interviews with 155 homeless persons and a postal survey to a general population sample, mainly based on the same questionnaire, including questions on social determinants of health and HRQoL measured with the EQ-5D. Chronic illness was three times more common among the homeless. HRQoL was worse among homeless persons than in the general population sample: the homeless reported more problems, especially more severe problems, in all the EQ-5D dimensions and had considerably lower EQ-5D(index) and EQ(VAS) score than the general population. Most problems were reported in the dimension anxiety/depression. Among the homeless, longer duration and more severe degree of homelessness lowered HRQoL, but few determinants were statistically significantly related to HRQoL. Having mental disease significantly lowered HRQoL. This study was an attempt to include hard-to-reach groups in an assessment of population health. Homeless persons had considerably worse HRQoL than the general population and reported most problems in the dimension anxiety/depression. Some diseases may contribute to causing homelessness; others may be seen as consequences. Homeless persons are a vulnerable group in society. Further interview studies are needed based on larger sample of homeless persons to explore health determinants such as sex, age, socioeconomic factors, duration and degree of homelessness, and health-related behaviours among the homeless persons.
International Nuclear Information System (INIS)
Bini, Donato; Felice, Fernando de; Geralico, Andrea
2006-01-01
The definition of relative accelerations and strains among a set of comoving particles is studied in connection with the geometric properties of the frame adapted to a 'fiducial observer'. We find that a relativistically complete and correct definition of strains must take into account the transport law of the chosen spatial triad along the observer's congruence. We use special congruences of (accelerated) test particles in some familiar spacetimes to elucidate such a point. The celebrated idea of Szekeres' compass of inertia, arising when studying geodesic deviation among a set of free-falling particles, is here generalized to the case of accelerated particles. In doing so we have naturally contributed to the theory of relativistic gravity gradiometer. Moreover, our analysis was made in an observer-dependent form, a fact that would be very useful when thinking about general relativistic tests on space stations orbiting compact objects like black holes and also in other interesting gravitational situations
Barth, Swaantje; Haas, Johannes-Peter; Schlichtiger, Jenny; Molz, Johannes; Bisdorff, Betty; Michels, Hartmut; Hügle, Boris; Radon, Katja
2016-01-01
Objective Aims of the study were to investigate health-related quality of life (HRQOL) in adult patients with former diagnosis of Juvenile Idiopathic Arthritis (JIA), to compare their HRQOL with the general population and to identify factors related to a poor outcome. Methods In 2012, a cross-sectional survey was performed by mailing a questionnaire to a large cohort of former and current patients of the German Centre for Rheumatology in Children and Adolescents. Only adult patients (?18 year...
Energy Technology Data Exchange (ETDEWEB)
Sole, E. [Pediatrics Service, Hospital Universitari Arnau de Vilanova, Lleida (Spain); Ballabriga, A.; Dominguez, C. [Centre d`Investigacions en Bioquimica y Biologia Molecular, Vall d`Hebron Hospitals, School of Medicine, Pediatrics Department, Universitat Autonoma de Barcelona, Barcelona (Spain)
1998-12-11
A cross-sectional was conducted on 254 individuals not occupationally exposed to lead to determine the degree of lead exposure in the general population of the Metropolitan Area of Barcelona. Blood lead levels (BPb) were analysed by atomic absorption spectrophotometry and zinc protoporphyrin (ZPP) by haemofluorimetry. Blood lead levels were analysed with respect to individuals` age, sex, area of residence, the season of the year the blood was drawn and ZPP. Mean blood lead in our series was 0.22{+-}0.011 {mu}mol/l (mean{+-}S.E.); no significant differences were found with respect to area of residence, sex or season. A linear relationship was observed between BPb and individuals` age (BPb=0.08+0.05xage; r=0.37). The prevalence of lead intoxication (BPb>0.48 {mu}mol/l) was 7.1%. No linear relationship was observed between BPb and ZPP. ZPP determination does not appear to be a good screening method for lead intoxication since it presents low specificity and sensitivity values with an area below the ROC curve similar to the null value line (area below the curve=0.5052, IC 95%=0.443-0.568). We conclude that lead exposure does not constitute a serious health problem in the area studied, since BPb levels found are far below the toxic limit and the prevalence of intoxication is similar to that reported in other studies conducted in other developed countries
Introduction to general relativity
Parthasarthy, R
2016-01-01
INTRODUCTION TO GENERAL RELATIVITY begins with a description of the geometry of curved space, explaining geodesics, parallel transport, covariant differentiation, geodesic deviation and spacetime symmetry by killing vectors. It then introduces Einstein's theory of gravitation followed by Schwarzschild solution with its relevance to Positive Mass theorem. The three tests for Einstein's gravity are explained. Other exact solutions such as Vaidya, Kerr and Reisner - Nordstrom metric are included. In the Chapter on cosmological solutions, a detailed description of Godel metric is provided. It then introduces five dimensional spacetime of Kaluza showing the unification of gravity with electromagnetism. This is extended to include non-Abelian gauge theory by invoking compact extra dimensions. Explicit expressions in this case for Christoffel connections and ricci tensor are derived and the higher dimensional gravity action is shown to compactification are given.
Health-Related Quality of Life of the General German Population in 2015: Results from the EQ-5D-5L.
Huber, Manuel B; Felix, Julia; Vogelmann, Martin; Leidl, Reiner
2017-04-16
The EQ-5D-5L is a widely used generic instrument to measure health-related quality of life. This study evaluates health perception in a representative sample of the general German population from 2015. To compare results over time, a component analysis technique was used that separates changes in the description and valuation of health states. The whole sample and also subgroups, stratified by sociodemographic parameters as well as disease affliction, were analyzed. In total, 2040 questionnaires (48.4% male, mean age 47.3 year) were included. The dimension with the lowest number of reported problems was self-care (93.0% without problems), and the dimension with the highest proportion of impairment was pain/discomfort (71.2% without problems). Some 64.3% of the study population were identified as problem-free. The visual analog scale (VAS) mean for all participants was 85.1. Low education was connected with significantly lower VAS scores, but the effect was small. Depression, heart disease, and diabetes had a strong significant negative effect on reported VAS means. Results were slightly better than those in a similar 2012 survey; the most important driver was the increase in the share of the study population that reported to be problem-free. In international comparisons, health perception of the general German population is relatively high and, compared with previous German studies, fairly stable over recent years. Elderly and sick people continue to report significant reductions in perceived health states.
Directory of Open Access Journals (Sweden)
Cassidy J David
2008-02-01
Full Text Available Abstract Background Little is known about the role of prior occupational low back injury in future episodes of low back pain and disability in the general population. We conducted a study to determine if a lifetime history of work-related low back injury is associated with prevalent severity-graded low back pain, depressive symptoms, or both, in the general population. Methods We used data from the Saskatchewan Health and Back Pain Survey – a population-based cross-sectional survey mailed to a random, stratified sample of 2,184 Saskatchewan adults 20 to 69 years of age in 1995. Information on the main independent variable was gathered by asking respondents whether they had ever injured their low back at work. Our outcomes, the 6-month period prevalence of severity-graded low back pain and depressive symptoms during the past week, were measured with valid and reliable questionnaires. The associations between prior work-related low back injury and our outcomes were estimated through multinomial and binary multivariable logistic regression with adjustment for age, gender, and other important covariates. Results Fifty-five percent of the eligible population participated. Of the 1,086 participants who responded to the question about the main independent variable, 38.0% reported a history of work-related low back injury. A history of work-related low back injury was positively associated with low intensity/low disability low back pain (OR, 3.66; 95%CI, 2.48–5.42, with high intensity/low disability low back pain (OR, 4.03; 95%CI, 2.41–6.76, and with high disability low back pain (OR, 6.76; 95%CI, 3.80–12.01. No association was found between a history of work-related low back injury and depression (OR, 0.85; 95%CI, 0.55–1.30. Conclusion Our analysis shows an association between past occupational low back injury and increasing severity of prevalent low back pain, but not depression. These results suggest that past work-related low back injury
Directory of Open Access Journals (Sweden)
Denollet Johan
2010-01-01
Full Text Available Abstract Background The objective was to review all available literature concerning Type D (distressed personality among the general population and to discuss its implications for research on health status, disease-promoting mechanisms and work-related problems in non-clinical populations. Methods A computerized search of the literature was performed independently and in duplicate by both investigators on December 21st, 2009. Published research reports were included if they studied Type D personality among the general population. Nineteen articles were selected and they were subjected to an 11-item standardised quality checklist by both investigators. Results The methodological quality of the selected studies was adequate to high. The studies included in this review showed that the presence of Type D characteristics had a negative impact on mental health status (more symptoms of depression, anxiety, post-traumatic stress disorder, mental distress, passive coping, and less social support and physical health status (more somatic complaints, lower health status, more influenza-like illness reporting. Other studies reported on behavioral and biological mechanisms of disease in apparently healthy individuals with a Type D personality. Finally, some studies also showed a negative effect of Type D personality on work-related problems (higher absence-leave, higher levels of vital exhaustion and burnout, and more work-related stress. Conclusions Type D personality is a vulnerability factor for general psychological distress that affects mental and physical health status and is associated with disease-promoting mechanisms and work-related problems in apparently healthy individuals.
DEFF Research Database (Denmark)
Wietlisbach, V; Marques-Vidal, P; Kuulasmaa, K
2013-01-01
BACKGROUND AND AIMS: The association between adiposity measures and dyslipidemia has seldom been assessed in a multipopulational setting. METHODS AND RESULTS: 27 populations from Europe, Australia, New Zealand and Canada (WHO MONICA project) using health surveys conducted between 1990 and 1997...... in adults aged 35-64 years (n = 40,480). Dyslipidemia was defined as the total/HDL cholesterol ratio >6 (men) and >5 (women). Overall prevalence of dyslipidemia was 25% in men and 23% in women. Logistic regression showed that dyslipidemia was strongly associated with body mass index (BMI) in men......, do not lead to optimal risk stratification for dyslipidemia in middle-age adults. Sex-specific adaptations are necessary, in particular by taking into account abdominal obesity in normal-weight men, post-menopausal age in women and regular smoking in both sexes....
Predictors of health related job loss: a two-year follow-up study in a general working population
DEFF Research Database (Denmark)
Haahr, J. P.; Frost, P.; Andersen, JH
2007-01-01
% to stress or stress related symptoms. HRJL involved low reemployment rate compared to non-HRJL. After multiple mutual adjustments, HRJL among females was associated with reports of a work compensation claim within the year previous to baseline (HR 3.0; 95% CI 1.6-5.1), high level of health anxiety (3.7; 2......INTRODUCTION: Job loss may be attributed to a number of causes. The medical profession is often involved in counselling or case work when citizens are excluded from work for health reasons. The aim of this study was to identify predictors of health related job loss (HRJL) in a cohort of Danish...... intervals (CI) were analysed. RESULTS: 4006 responses were obtained at baseline (71.5%), and 3,276 (81.8%) at follow up. About 567 (17.3%) had lost their job, and 135 (23.8%) reported HRJL. 51.5% of HRJL was related to pain, disease, or discomfort in the neck, the back, arms, or legs, and another 23...
Conformally Coupled General Relativity
Directory of Open Access Journals (Sweden)
Andrej Arbuzov
2018-02-01
Full Text Available The gravity model developed in the series of papers (Arbuzov et al. 2009; 2010, (Pervushin et al. 2012 is revisited. The model is based on the Ogievetsky theorem, which specifies the structure of the general coordinate transformation group. The theorem is implemented in the context of the Noether theorem with the use of the nonlinear representation technique. The canonical quantization is performed with the use of reparametrization-invariant time and Arnowitt– Deser–Misner foliation techniques. Basic quantum features of the models are discussed. Mistakes appearing in the previous papers are corrected.
Directory of Open Access Journals (Sweden)
Stephen CL Gough
2009-11-01
Full Text Available Stephen CL Gough,1 Nana Kragh,2 Uffe Jon Ploug,2 Mette Hammer21University of Birmingham and University Hospital Birmingham NHS Foundation Trust, Birmingham, UK; 2Novo Nordisk A/S Global Health Economics and Outcomes Research Krogshojvej 55, DK-2880 Bagsvaerd, DenmarkBackground: Weight gain can contribute towards the development of type 2 diabetes (T2D, and some treatments for T2D can lead to weight gain. The aim of this study was to determine whether having T2D and also being obese had a greater or lesser impact on health-related quality of life (HRQoL than having either of the two conditions alone.Methods: The 2003 dataset of the Health Survey for England (HSE was analyzed using multiple regression analyses to examine the influence of obesity and T2D on HRQoL, and to determine whether there was any interaction between these two disutilities.Results: T2D reduced HRQoL by 0.029 points, and obesity reduced HRQoL by 0.027 points. There was no significant interaction effect between T2D and obesity, suggesting that the effect of having both T2D and being obese is simply additive and results in a reduction in HRQoL of 0.056.Conclusions: Based on analysis of HSE 2003 data, people with either T2D or obesity experience significant reduction in HRQoL and people with both conditions have a reduction in HRQoL equal to the sum of the two independent effects. The effect of obesity on HRQoL in people with T2D should be considered when selecting a therapy.Keywords: diabetes, health-related quality of life, obesity, type 2 diabetes, England
Twistors in general relativity
International Nuclear Information System (INIS)
Penrose, R.
1987-01-01
The two most significant definitions of a twistor in (conformally) flat space-time are that given by solutions of the twistor equation and that given by α-planes in the complexification of the space-time. It is shown that these concepts are naturally dual to one another, and that they give rise to various different twistor concepts in curved space-time when referred to submanifolds of differing dimension. One of these concepts, that of 2-surface twistors, gives rise to a quasi-local definition of mass (and angular momentum). The status of this definition is explored in relation to various examples. (author)
Gilchrist, Elizabeth Allison; Ireland, Lana; Forsyth, Alasdair; Godwin, Jon; Laxton, Tim
2017-01-01
Scotland has a particular problem with alcohol, and the links between intimate partner abuse (IPA) and alcohol appear stronger here than elsewhere across Europe. This study explored differences in alcohol use, related aggression and relationship conflict across a number of groups: men convicted for intimate partner abuse, men convicted of general offences and men recruited from community sports teams. Participants (n = 64) completed three questionnaires exploring their experiences of alcohol use (Alcohol Use Disorders Identification Test, AUDIT); alcohol and aggression (Alcohol Related Aggression Questionnaire, ARAQ-28), and relationship conflict (Revised Conflict Tactics Scale, CTS-2). There were significant differences across the groups in terms of AUDIT and ARAQ-28 scores, IPA and general offenders scored higher than the community sample. CTS-2 scores showed significant differences: both offender groups reported more use of negotiation and psychological abuse, than the community men, and IPA offenders reported causing more physical harm than either general offenders or the community sample. ARAQ-28 scores correlated with psychological abuse for general offenders. Alcohol use was very high across all groups, but the community group did not endorse an aggression-precipitating view of alcohol and did not report high IPA. Discussed is the need for cross-cultural research to explore putative mediators and moderators in the relationship between alcohol, aggressiveness and IPA. [Gilchrist EA, Ireland L, Forsyth A, Godwin J, Laxton T. Alcohol use, alcohol-related aggression and intimate partner abuse: A cross-sectional survey of convicted versus general population men in Scotland. Drug Alcohol Rev 2017;36:20-23]. © 2017 Australasian Professional Society on Alcohol and other Drugs.
Directory of Open Access Journals (Sweden)
Xiu Yun Wu
Full Text Available The association between physical activity, sedentary behavior and health-related quality of life in children and adolescents has been mostly investigated in those young people with chronic disease conditions. No systematic review to date has synthesized the relationship between physical activity, sedentary behavior and health-related quality of life in the general healthy population of children and adolescents. The purpose of this study was to review systematically the existing literature that evaluated the relations between physical activity, sedentary behavior and health-related quality of life in the general population of children and adolescents.We conducted a computer search for English language literature from databases of MEDLINE, EMBASE, PSYCINFO and PubMed-related articles as well as the reference lists of existing literature between 1946 and the second week of January 2017 to retrieve eligible studies. We included the studies that assessed associations between physical activity and/or sedentary behavior and health-related quality of life among the general population of children and adolescents aged between 3-18 years. The study design included cross-sectional, longitudinal and health intervention studies. We excluded the studies that examined associations between physical activity, sedentary behavior and health-related quality of life among children and adolescents with specific chronic diseases, and other studies and reports including reviews, meta-analyses, study protocols, comments, letters, case reports and guidelines. We followed up the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA statement in the reporting of this review. The risk of bias of the primary studies was assessed by the Newcastle-Ottawa Scale. We synthesized the difference in health-related quality of life scores between different levels of physical activity and sedentary time.In total, 31 studies met the inclusion criteria and were
Stefansson, Vidar T N; Schei, Jørgen; Solbu, Marit D; Jenssen, Trond G; Melsom, Toralf; Eriksen, Bjørn O
2018-05-01
Rapid age-related glomerular filtration rate (GFR) decline increases the risk of end-stage renal disease, and a low GFR increases the risk of mortality and cardiovascular disease. High body mass index and the metabolic syndrome are well-known risk factors for patients with advanced chronic kidney disease, but their role in accelerating age-related GFR decline independent of cardiovascular disease, hypertension and diabetes is not adequately understood. We studied body mass index, waist circumference, waist-hip ratio and metabolic syndrome as risk factors for accelerated GFR decline in 1261 middle-aged people representative of the general population without diabetes, cardiovascular disease or kidney disease. GFR was measured as iohexol clearance at baseline and repeated after a median of 5.6 years. Metabolic syndrome was defined as fulfilling three out of five criteria, based on waist circumference, blood pressure, glucose, high-density lipoprotein cholesterol and triglycerides. The mean GFR decline rate was 0.95 ml/min/year. Neither the body mass index, waist circumference nor waist-hip ratio predicted statistically significant changes in age-related GFR decline, but individuals with baseline metabolic syndrome had a significant mean of 0.30 ml/min/year faster decline than individuals without metabolic syndrome in a multivariable adjusted linear regression model. This association was mainly driven by the triglyceride criterion of metabolic syndrome, which was associated with a significant 0.36 ml/min/year faster decline when analyzed separately. Results differed significantly when GFR was estimated using creatinine and/or cystatin C. Thus, metabolic syndrome, but not the body mass index, waist circumference or waist-hip ratio, is an independent risk factor for accelerated age-related GFR decline in the general population. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Skogstad Laila
2011-04-01
Full Text Available Abstract Background Trauma patients have impaired health-related quality of life (HRQOL after trauma. The aim of the study was to assess HRQOL during the first year after trauma and hospital stay in trauma patients admitted to an intensive-care unit (ICU for >24 hours compared with non-ICU trauma patients and the general population, and to identify predictors of HRQOL. Methods A prospective one-year follow-up study of 242 trauma patients received by the trauma team of a trauma referral centre in Norway was performed. HRQOL was measured using the Medical Outcomes Study Short Form 36 (SF-36 at 3 and 12 months. Results The mean age of the cohort was 42.3 years (95% CI, 40.4-44.3 years. The median Injury Severity Score (ISS was 10, interquartile range 16. The HRQOL improved significantly from the 3 to the 12 months follow up in the trauma patients. However their scores were significantly lower for most subscales of SF-36 compared to the general population. Significant differences between ICU and non-ICU patients at 12 months were observed only for physical functioning and role physical subscales. Optimism was an independent predictor of good HRQOL at 12 months, in all dimensions (beta, 0.95-2.45. A higher depression score at baseline predicted lower HRQOL in four of eight dimensions (beta -1.1 to -1.70. In addition, better physical functioning was predicted by lower age (beta, -0.20, and having head injury (reference as the most severe injury vs. spine or extremity injuries (beta, -9.49 and -10.85, and better mental health by higher age (beta, 0.21 and being employed or studying before the trauma (beta, 12.27. In addition to optimism good general health was predicted by lower score for post-traumatic stress (PTS symptoms at baseline (beta, -0.27 and lower ISS score (beta -10.59. Conclusions The HRQOL improved significantly from the 3 to the 12 months follow up in our sample. However their scores were significantly lower for most subscales of SF-36
Hemochromatosis mutations in the general population
DEFF Research Database (Denmark)
Andersen, Rolf Vaern; Tybjaerg-Hansen, Anne; Appleyard, Merete
2004-01-01
The progression rate of iron overload in hereditary hemochromatosis in individuals in the general population is unknown. We therefore examined in the general population iron overload progression rate in C282Y homozygotes. Using a cohort study of the Danish general population, The Copenhagen City...... saturation and ferritin levels increased slightly in male and female C282Y homozygotes. None of the C282Y homozygotes developed clinically overt hemochromatosis. In conclusion, individuals in the general population with C282Y homozygosity at most demonstrate modest increases in transferrin saturation...
General relativity basics and beyond
Date, Ghanashyam
2015-01-01
A Broad Perspective on the Theory of General Relativity and Its Observable Implications General Relativity: Basics and Beyond familiarizes students and beginning researchers with the basic features of the theory of general relativity as well as some of its more advanced aspects. Employing the pedagogical style of a textbook, it includes essential ideas and just enough background material needed for readers to appreciate the issues and current research. Basics The first five chapters form the core of an introductory course on general relativity. The author traces Einstein’s arguments and presents examples of space-times corresponding to different types of gravitational fields. He discusses the adaptation of dynamics in a Riemannian geometry framework, the Einstein equation and its elementary properties, and different phenomena predicted or influenced by general relativity. Beyond Moving on to more sophisticated features of general relativity, the book presents the physical requirements of a well-defined de...
Slieker ten Hove, M.C.; Pool-Goudzwaard, A.L.; Eijkemans, M.J.; Steegers-Theunissen, R. P M; Burger, C.; Vierhout, ME
2009-01-01
INTRODUCTION AND HYPOTHESIS: In selected populations, pelvic organ prolapse (POP) was associated with bladder/bowel symptoms, but data on the general female population are lacking. Our aim was to obtain normative data on the prevalence of POP and pelvic floor dysfunction (PFD) symptoms and signs and
Slieker-ten Hove, M.C.; Pool-Goudzwaard, A.; Eijkemans, M.J.; Steegers-Theunissen, R.P.M.; Burger, C.W.; Vierhout, M.E.
2009-01-01
INTRODUCTION AND HYPOTHESIS: In selected populations, pelvic organ prolapse (POP) was associated with bladder/bowel symptoms, but data on the general female population are lacking. Our aim was to obtain normative data on the prevalence of POP and pelvic floor dysfunction (PFD) symptoms and signs and
Lam, Cindy Lo Kuen; Guo, Vivian Yawei; Wong, Carlos King Ho; Yu, Esther Yee Tak; Fung, Colman Siu Cheung
2017-06-01
To assess health-related quality of life (HRQOL) among Chinese adults from low-income households in Hong Kong, and to explore any threshold of household income that impaired HRQOL. A cross-sectional analysis was conducted on 298 adults from low-income families when they enrolled into a cohort study between 2012 and 2014. HRQOL was measured by the 12-item Short-Form Health Survey-version 2 (SF-12v2). Their mean SF-12v2 subscale and summary scores were compared with those of 596 age-sex-matched subjects randomly selected from a database of 2763 adults from the Hong Kong general population (ratio = 1:2). Multiple linear regressions were conducted to determine any association between monthly household income and HRQOL. Subjects from low-income households had significantly lower SF-12v2 bodily pain, general health, vitality and physical component summary (PCS) scores than the age-sex matched subjects from the general population. Subgroup analysis showed that a household income income in Hong Kong (HK$10 000 ≈ US$1290, i.e. poverty line in Hong Kong) was independently associated with poorer PCS and mental component summary (MCS) scores after adjustment for socio-demographics and co-morbidities. Chinese adults from low-income households had poorer HRQOL, and income seems to be the threshold for impairment of both physical and mental HRQOL. The findings support the current definition of the poverty line. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
de Lossada, A; Rejas, J
2016-10-01
Smoking has been associated with an important health risk. The aim was to analyze the health-related quality of life (HRQoL) status of the adult Spanish general population included in the National Health Survey according to its smoking status. Data were included from National Health Survey for the year 2011-2012 with information of HRQoL status in general population over 15 years of age. Adult male and female, 18 years of age or above, were categorized into 3 exclusive groups according to their current smoking status: smokers (daily smokers of any form of tobacco, at least the previous 12 months), ex-smokers of one or more years since quitting smoking and people who have never smoked (non smokers). HRQoL was assessed with the Spanish version of the EQ-5D-5L questionnaire included into the National Health Survey. A total of 19,604 records were analyzed: 4,723 (24.09%) smokers, 3,797 (19.37%) ex-smokers, and 11,084 (56.54%) non smokers, male and female with 18 years of age or above. Smokers showed significantly adjusted mean scores (95% CI) in utility of 0.903 (0.899-0.908) and 75.36 (74.06-76.69) in the visual analogue scale of current state of health, ex-smokers 0.924 (0.919-0.929) and 76.85 (76.67-78.07), and non smokers 0.902 (0.899-0.905) and 76.25 (75.02-77.51), P<.01 between groups in both variables. In the Spanish general population, subjects who are ex-smokers showed better utility values and state health scores, supporting the hypothesis that quitting smoking could be associated with a discreet improvement of HRQoL. Copyright © 2015 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.
Gasull, Magda; Pumarega, José; Rovira, Gemma; López, Tomàs; Alguacil, Juan; Porta, Miquel
2013-10-01
Scant evidence is available worldwide on the relative influence of occupational social class and educational level on body concentrations of persistent organic pollutants (POPs) in the general population. The objective was to analyse such influence in a representative sample of the general population of Catalonia, Spain. Participants in the Catalan Health Interview Survey aged 18-74 were interviewed face-to-face, gave blood, and underwent a physical exam. The role of age, body mass index (BMI), and parity was analysed with General Linear Models, and adjusted geometric means (GMs) were obtained. Crude (unadjusted) concentrations were higher in women and men with lower education, and in women, but not men, in the less affluent social class. After adjusting for age, in women there were no associations between POP levels and social class or education. After adjusting for age and BMI, men in the less affluent class had higher p,p'-DDE concentrations than men in class I (p-value=0.016), while men in class IV had lower HCB than men in the upper class (p-valuesocial class were co-adjusted for, some positive associations with education in men remained statistically significant, whereas class remained associated only with p,p'-DDE. Educational level influenced blood concentrations of POPs more than occupational social class, especially in men. In women, POP concentrations were mainly explained by age/birth cohort, parity and BMI. In men, while concentrations were also mainly explained by age/birth cohort and BMI, both social class and education showed positive associations. Important characteristics of socioeconomic groups as age and BMI may largely explain crude differences among such groups in internal contamination by POPs. The absence of clear patterns of relationships between blood concentrations of POPs and indicators of socioeconomic position may fundamentally be due to the widespread, lifelong, and generally invisible contamination of human food webs. Decreasing
Sterud, Tom
2014-07-01
This study aimed to examine gender differences in physician-certified sick leave and the extent to which these differences can be explained by work-related psychosocial and mechanical risk factors. Randomly drawn from the general population in Norway, the cohort comprised working men and women aged 18-69 years (N=12 255, response rate at baseline = 60.9%). Eligible respondents were interviewed in 2009 and registered with an active employee relationship of ≥ 100 actual working days in 2009 and 2010 (N=3688 men and 3070 women). The study measured 11 work-related psychosocial factors and 11 mechanical exposures, and outcomes of interest were physician-certified general sick leave (GSL) >0 days and long-term sick leave (LTSL) ≥ 40 working days during 2010. Women reported a significantly higher level of exposure to 9 of the 11 psychosocial factors evaluated. For mechanical factors, the reporting was mixed. After controlling for age, educational level, sick leave during 2009, housework, working hours and family status, a 1.7-fold risk for GSL and LTSL were found among women. In comparison with the initial model, adjusting for psychosocial factors reduced the excess risk by 21% and 27% for GSL and LTSL, respectively. The total effect of mechanical factors was negligible. Differences between occupations held by women and men explained an additional one-tenth of the excess risk for LTSL among women. Work-related psychosocial factors contributed significantly to a higher level of GSL and LTSL among women. The most important factors were demands for hiding emotions, emotional demands, and effort-payment imbalance.
Directory of Open Access Journals (Sweden)
Rochat Thierry
2008-02-01
Full Text Available Abstract Background Few epidemiologic studies have assessed health-related quality of life (HRQL of asthma patients from a general population and it is unclear which instrument is best suitable for this purpose. We investigated the validity of the Asthma Quality of Life Questionnaire (AQLQ and the SF-36 completed by individuals with asthma from the population-based SAPALDIA (Swiss study on air pollution and lung diseases in adults cohort. Methods The study included 258 participants with a physician-diagnosed asthma who had completed the AQLQ and SF-36. We assessed floor and ceiling effects, internal consistency reliability and cross-sectional validity with a priori hypotheses that correlations between the specific HRQL domains (e.g. "symptoms" or "physical functioning" and the corresponding external validation measures (respiratory symptoms, need for doctor visits, limitation in activities due to asthma and lung function would capture similar aspects and be correlated moderately (≥ 0.3 to strongly (≥ 0.5, whereas non-corresponding domains be correlated weakly with each other ( Results The AQLQ showed pronounced ceiling effects with all median domain scores above 6 (scores varied from 1–7. For the SF-36, ceiling effects were present in 5 out of 8 domains. Cronbach's alpha was >0.7 for all AQLQ and SF-36 domains. Correlations between the AQLQ domains "respiratory symptoms", "activity limitation" and "environmental exposure", and the validation measures ranged from 0.29–0.57. Correlations between the "emotional function" domain and the validation measures were also in this range (0.31–0.55 and not as low as we hypothesized. For the SF-36, correlations between "physical functioning" and "role physical", and the validation measures ranged from 0.25–0.56, whereas "role emotional" and "mental health" correlated with these measures from 0.01–0.23. Conclusion The AQLQ and the SF-36 showed fairly good internal consistency. Both instruments
Modern canonical quantum general relativity
Thiemann, Thomas
2007-01-01
This is an introduction to the by now fifteen years old research field of canonical quantum general relativity, sometimes called "loop quantum gravity". The term "modern" in the title refers to the fact that the quantum theory is based on formulating classical general relativity as a theory of connections rather than metrics as compared to in original version due to Arnowitt, Deser and Misner. Canonical quantum general relativity is an attempt to define a mathematically rigorous, non-perturbative, background independent theory of Lorentzian quantum gravity in four spacetime dimensions in the continuum. The approach is minimal in that one simply analyzes the logical consequences of combining the principles of general relativity with the principles of quantum mechanics. The requirement to preserve background independence has lead to new, fascinating mathematical structures which one does not see in perturbative approaches, e.g. a fundamental discreteness of spacetime seems to be a prediction of the theory provi...
Cosmological tests of general relativity
International Nuclear Information System (INIS)
Hut, P.
1977-01-01
It is stated that the general relativity theory could be tested on a cosmological scale by measuring the Hubble constant and the deceleration parameter, if, in addition, everything could be known about the matter filling the universe. If, on the other hand, nothing could be presupposed about the matter content of the universe general relativity could not be tested by measuring any number of time derivatives of the scale factor. But upon making the assumption of a universe filled with non-interacting mixture of non-relativistic matter and radiation general relativity can in principle be tested by measuring the first five derivatives of the scale factor. Some general relations are here presented using this assumption. (author)
Geometrical optics in general relativity
Loinger, A.
2006-01-01
General relativity includes geometrical optics. This basic fact has relevant consequences that concern the physical meaning of the discontinuity surfaces propagated in the gravitational field - as it was first emphasized by Levi-Civita.
Cosmic frontiers of general relativity
International Nuclear Information System (INIS)
Kaufmann, W.J. III.
1977-01-01
All relevant topics in general astronomy are covered including orientation in space--time, special relativity, gravitation and general relativity, stars and stellar evolution, white dwarfs, pulsars, neutron stars, the black hole, the geometry of the Schwarzschild solution, and electrically charged and rotating black holes. Also the geometry of the Kerr solution, observations of black holes, white holes and particle creation, gravitational waves and lenses, exploding galaxies and massive and primordial black holes are discussed
The power of general relativity
International Nuclear Information System (INIS)
Clifton, Timothy; Barrow, John D.
2005-01-01
We study the cosmological and weak-field properties of theories of gravity derived by extending general relativity by means of a Lagrangian proportional to R 1+δ . This scale-free extension reduces to general relativity when δ→0. In order to constrain generalizations of general relativity of this power class, we analyze the behavior of the perfect-fluid Friedmann universes and isolate the physically relevant models of zero curvature. A stable matter-dominated period of evolution requires δ>0 or δ -19 assuming that Mercury follows a timelike geodesic. The combination of these observational constraints leads to the overall bound 0≤δ -19 on theories of this type
Advanced mechanics and general relativity an introduction to general relativity
Franklin, Joel
2010-01-01
Aimed at advanced undergraduates with background knowledge of classical mechanics and electricity and magnetism, this textbook presents both the particle dynamics relevant to general relativity, and the field dynamics necessary to understand the theory. Focusing on action extremization, the book develops the structure and predictions of general relativity by analogy with familiar physical systems. Topics ranging from classical field theory to minimal surfaces and relativistic strings are covered in a homogeneous manner. Nearly 150 exercises and numerous examples throughout the textbook enable students to test their understanding of the material covered.
Somatic symptom profiles in the general population
DEFF Research Database (Denmark)
Eliasen, Marie; Jørgensen, Torben; Schröder, Andreas
2017-01-01
PURPOSE: The aim of this study was to identify and describe somatic symptom profiles in the general adult population in order to enable further epidemiological research within multiple somatic symptoms. METHODS: Information on 19 self-reported common somatic symptoms was achieved from a population...
Generalized Moshinsky bracket recurrence relations
International Nuclear Information System (INIS)
Bevelacqua, J.J.
1979-01-01
Recurrence relations for generalized Talmi-Moshinsky brackets are derived. These relations permit the generation of transformation brackets once appropriate starting brackets are determined. The savings in computer time, when compared with generating brackets individually, is at least a factor of 10 for brackets with radial quantum numbers as large as 9 and angular quantum numbers as large as 2. (author)
Spinning fluids in general relativity
Ray, J. R.; Smalley, L. L.
1982-01-01
General relativity field equations are employed to examine a continuous medium with internal spin. A variational principle formerly applied in the special relativity case is extended to the general relativity case, using a tetrad to express the spin density and the four-velocity of the fluid. An energy-momentum tensor is subsequently defined for a spinning fluid. The equations of motion of the fluid are suggested to be useful in analytical studies of galaxies, for anisotropic Bianchi universes, and for turbulent eddies.
Schäfer, T; Przybilla, B
1996-06-01
Determination of Hymenoptera venom (HV)-specific serum IgE antibodies is a useful diagnostic method in patients with systemic anaphylactic reaction (SAR) to Hymenoptera stings. In a general population cohort, we determined the prevalence of SAR and HV-specific IgE antibodies and assessed parameters associated with the latter. A total of 277 voluntarily participating inhabitants of rural Bavaria (Germany) (232 adults, mean age 38.0 years; 45 children, mean age 8.4 years) were investigated for a history of atopic disease or SAR to insect stings; in 258 of these, total IgE and specific IgE antibodies to HV (Apis mellifera, Vespula vulgaris/germanica) and four common aeroallergens (birch pollen, grass pollen, house-dust mite, and cat dander) in the serum were determined. Nine (3.3%) subjects reported SAR to insect stings. In 27.1% of the sera, specific IgE antibodies to HV were found, to bee venom in 24.8%, and to wasp venom in 8.5% (P 100 kU/l was found in 22.5%. Specific serum IgE to HV was significantly associated with male sex (female vs. male, OR = 0.47; CI 0.25-0.86), young age (children vs. adults, OR = 2.80; CI 1.25-6.28), a history of SAR to insect stings (OR = 4.16; CI 1.15-15.03), total sIgE > 100 kU/l (OR = 3.88; CI 1.98-7.60), and specific IgE antibodies to three of the four aeroallergens (grass pollen, OR = 7.24 CI 3.66-14.38; birch pollen, OR = 3.67 CI 1.54-8.81; and house-dust mite, OR = 4.61 CI 2.08-10.32). It is concluded that immunologic sensitization to HV is common in the general population and is associated with atopy-related humoral IgE hyperresponsiveness.
Directory of Open Access Journals (Sweden)
Torén K
2017-08-01
Full Text Available Kjell Torén,1,2 Nicola Murgia,1,2 Anna-Carin Olin,1 Jan Hedner,3 John Brandberg,4 Annika Rosengren,5 Göran Bergström51Section of Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden; 2Section of Occupational Medicine, Respiratory Diseases and Toxicology, University of Perugia, Italy; 3Department of Medicine/Lung Medicine, Sahlgrenska Academy, University of Gothenburg, 4Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 5Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden Background: In epidemiological studies, items about physician-diagnosed COPD are often used. There is a lack of validation and standardization of these items.Materials and methods: In a general population-based study, 1,050 subjects completed a questionnaire and performed spirometry, including forced expiratory volume in 1 second (FEV1 and forced vital capacity (FVC after inhalation of 400 µg of salbutamol. COPD was defined as the ratio of FEV1/FVC <0.7 after bronchodilation. Physician-diagnosed COPD was defined as an affirmative answer to the single item: “Have you ever had COPD diagnosed by a physician?”, physician-diagnosed COPD/emphysema as an affirmative answer to any of the two single items; “Have you ever had COPD diagnosed by a physician?” or “Have you ever been told by a physician that you have emphysema?”, physician-diagnosed chronic bronchitis as an affirmative answer to; “Have you ever been told by a physician that you have chronic bronchitis?” and physician-diagnosed COPD, emphysema or chronic bronchitis was defined as an affirmative answer to either of the three items above.Results: For the single item about physician-diagnosed COPD, the sensitivity was around 0.11 and the specificity was almost 0.99 in relation to COPD. The sensitivity of the combined items about COPD
Pseudo-complex general relativity
Hess, Peter O; Greiner, Walter
2016-01-01
This volume presents an pseudo-complex extension of General Relativity which addresses these issues and presents proposals for experimental examinations in strong fields near a large mass. General Relativity is a beautiful and well tested theory of gravitation. Nevertheless, it implies conceptual problems like the creation of singularities (Black Holes) as a result of the collapse of large masses, or the appearance of event horizons which exclude parts of the space-time from the observation of external observers. The mathematical and geometrical foundations of this extension are displayed in detail, and applications including orbits and accretion disks around large central masses, neutron stars or cosmological models are introduced. Calculations both for classical and extended applications are often executed in the form of problems with extensive solutions, which makes this volume also a valuable resource for any student of General Relativity.
Søholm, Helle; Kjaergaard, Jesper; Thomsen, Jakob Hartvig; Bro-Jeppesen, John; Lippert, Freddy K; Køber, Lars; Wanscher, Michael; Hassager, Christian
2014-11-01
Performing exercise is shown to prevent cardiovascular disease, but the risk of an out-of-hospital cardiac arrest (OHCA) is temporarily increased during strenuous activity. We examined the etiology and outcome after successfully resuscitated OHCA during exercise in a general non-athletic population. Consecutive patients with OHCA were admitted with return of spontaneous circulation (ROSC) or on-going resuscitation at hospital arrival (2002-2011). Patient charts were reviewed for post-resuscitation data. Exercise was defined as moderate/vigorous physical activity. A total of 1393 OHCA-patients were included with 91(7%) arrests occurring during exercise. Exercise-related OHCA-patients were younger (60 ± 13 vs. 65 ± 15, p<0.001) and predominantly male (96% vs. 69%, p<0.001). The arrest was more frequently witnessed (94% vs. 86%, p=0.02), bystander CPR was more often performed (88% vs. 54%, p<0.001), time to ROSC was shorter (12 min (IQR: 5-19) vs. 15 (9-22), p=0.007) and the primary rhythm was more frequently shock-able (91% vs. 49%, p<0.001) compared to non-exercise patients. Cardiac etiology was the predominant cause of OHCA in both exercise and non-exercise patients (97% vs. 80%, p<0.001) and acute coronary syndrome was more frequent among exercise patients (59% vs. 38%, p<0.001). One-year mortality was 25% vs. 65% (p<0.001), and exercise was even after adjustment associated with a significantly lower mortality (HR=0.40 (95%CI: 0.23-0.72), p=0.002). OHCA occurring during exercise was associated with a significantly lower mortality in successfully resuscitated patients even after adjusting for confounding factors. Acute coronary syndrome was more common among exercise-related cardiac arrest patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Bimetric general relativity and cosmology
International Nuclear Information System (INIS)
Rosen, N.
1980-01-01
A modification of the general relativity theory is proposed (bimetric general relativity) in which, in addition to the usual metric tensor gsub(μupsilon) describing the space-time geometry and gravitation, there exists also a background metric tensor γsub(μupsilon). The latter describes the space-time of the universe if no matter were present and is taken to correspond to a space-time of constant curvature with positive spatial curvature (k = 1). Field equations are obtained, and these agree with the Einstein equations for systems that are small compared to the size of the universe, such as the solar system. Energy considerations lead to a generalized form of the De Donder condition. Simple isotropic closed models of the universe can be set up which first contract and then expand without going through a singular state. It is suggested that the maximum density of the universe was of the order of c 5 -h -1 G -2 approximately 10 93 g/cm 3 . The expansion from such a high-density state is similar to that from the singular state ('big bang') of the general relativity models. In the case of the dust-filled model the parameters can be fitted to present cosmological data. Using the radiation-filled model to describe the early history of the universe, the cosmic abundance of helium and other light elements can be accounted for in the same way as in ordinary general relativity. (author)
Conformal covariance of general relativity
International Nuclear Information System (INIS)
Ionescu-Pallas, N.; Gottlieb, I.
1980-01-01
The Einstein's equations of General Relativity are written in a conformal metric, resulting as a consequence of geometrizing the pressure forces. Accordingly, the trajectory of a test body pursues a geodetic line even inside the source of gravitational field. Moreover, the pressure, entering the perfect fluid scheme, may be replaced by a certain scalar interaction. This new manner of interpreting General Relativity is then applied to Cosmology, in order to build up a model of Universe whose static limit should coincide with that of Einstein. At the same time, the cosmological constant is connected to the scalar interaction acquiring a plausible explanation. (author)
The gauge in general relativity
International Nuclear Information System (INIS)
Cohn, J.
1975-01-01
The view is taken that the field equations of General Relativity, without a definition of congruence of length and time intervals at different events, are without physical content. The possibility is explored that the customary Einstein field equations are to be used but with a different congruence definition than is customary. When these resulting equations are, in turn, expressed with the customary congruence, they comprise a new set of field equations physically not equivalent to either Einstein's or Brans-Dicke's formulations of general relativity. Similarities with Einstein's and Brans-Dicke's formulations are discussed, and the possibility of experimental confirmation of these new equations is also briefly considered. (author)
General relativity and gravitational waves
Weber, Johanna
1961-01-01
An internationally famous physicist and electrical engineer, the author of this text was a pioneer in the investigation of gravitational waves. Joseph Weber's General Relativity and Gravitational Waves offers a classic treatment of the subject. Appropriate for upper-level undergraduates and graduate students, this text remains ever relevant. Brief but thorough in its introduction to the foundations of general relativity, it also examines the elements of Riemannian geometry and tensor calculus applicable to this field.Approximately a quarter of the contents explores theoretical and experimenta
General relativity 50 years old
1966-01-01
In May 1916, 'The Foundations of General Relativity Theory' by Albert Einstein was published in 'Annalen der Physik'. Fifty years later, this major contribution to scientific thought still has a rather isolated position with respect to the main-stream of scientific theory. (In contrast, the Special Theory of Relativity is one of the cornerstones of sub-nuclear physics.) To mark the anniversary of the publication of Einstein's paper a theoretician from CERN discusses the theory and its present status.
Quantum mechanics from general relativity
International Nuclear Information System (INIS)
Sachs, M.
1986-01-01
A generalization of quantum mechanics is demonstrated in the context of general relativity, following from a generally covariant field theory of inertia. Nonrelativistically, the formalism corresponds with linear quantum mechanics. In the limit of special relativity, nonlinearity remains and several new features are derived: (1) Particle-antiparticle pairs do not annihilate; an exact bound state solution is derived corresponding with all experimental facts about annihilation/creation - which, in approximation, gives the blackbody radiation spectrum for a sea of such pairs. (2) A result is proven, without approximation, that is physically equivalent to the Pauli exclusion principle - which, in linear approximation, gives the totally antisymmetrised many-body wave function and Fermi-Dirac statistics. (3) The hydrogen spectrum is derived, including the Lamb shifts, in agreement with experiment; new results are found for high energy electron-proton scattering. (4) Finally, several applications to the elementary particle domain are demonstrated, in agreement with results from experimental high energy physics. (Auth.)
General Relativity: horizons for tests
Yatskiv, Ya. S.; Alexandrov, A. N.; Vavilova, I. B.; Zhdanov, V. I.; Zhuk, A. I.; Kudrya, Yu. N.; Parnovsky, S. L.; Fedorova, E. V.; Khmil, S. V.
2013-12-01
Theoretical basis of the General Relativity Theory (GRT), its experimental tests as well as GRT applications are briefly summarized taking into account the results of the last decade. The monograph addresses scientists, post-graduated students, and students specialized in the natural sciences as well as everyone who takes an interest in GRT.
General relativity and dark matter
International Nuclear Information System (INIS)
Pestov, A.B.
1993-01-01
It is shown that from the first principles of General Relativity it follows that there exists a new type of interactions which are tightly connected with the gravitational interactions. New particles representing a new form of interactions do not interact electromagnetically, strongly and weakly with the known elementary particles. Physics of the new particles is defined by the Planck scales. (author.). 9 refs
General Relativity: Geometry Meets Physics
Thomsen, Dietrick E.
1975-01-01
Observing the relationship of general relativity and the geometry of space-time, the author questions whether the rest of physics has geometrical explanations. As a partial answer he discusses current research on subatomic particles employing geometric transformations, and cites the existence of geometrical definitions of physical quantities such…
Modified General Relativity and Cosmology
Abdel-Rahman, A.-M. M.
1997-10-01
Aspects of the modified general relativity theory of Rastall, Al-Rawaf and Taha are discussed in both the radiation- and matter-dominated flat cosmological models. A nucleosynthesis constraint on the theory's free parameter is obtained and the implication for the age of the Universe is discussed. The consistency of the modified matter- dominated model with the neoclassical cosmological tests is demonstrated.
Algebraic computing in general relativity
International Nuclear Information System (INIS)
D'Inverno, R.A.
1975-01-01
The purpose of this paper is to bring to the attention of potential users the existence of algebraic computing systems, and to illustrate their use by reviewing a number of problems for which such a system has been successfully used in General Relativity. In addition, some remarks are included which may be of help in the future design of these systems. (author)
Cosmological models in general relativity
Indian Academy of Sciences (India)
Cosmological models in general relativity. B B PAUL. Department of Physics, Nowgong College, Nagaon, Assam, India. MS received 4 October 2002; revised 6 March 2003; accepted 21 May 2003. Abstract. LRS Bianchi type-I space-time filled with perfect fluid is considered here with deceler- ation parameter as variable.
Dimensional Analysis and General Relativity
Lovatt, Ian
2009-01-01
Newton's law of gravitation is a central topic in the first-year physics curriculum. A lecturer can go beyond the physical details and use the history of gravitation to discuss the development of scientific ideas; unfortunately, the most recent chapter in this history, general relativity, is not covered in first-year courses. This paper discusses…
Al-Mutairi, Nawaf; Issa, Bayoumi Ibrahim; Nair, Vasanthy
2012-01-01
The primary cause of skin cancers is exposure to ultraviolet (UV) radiation. And, for decades sun protection has been promoted in various public health education campaigns. Recently, however, vitamin D deficiency has been related to increased risk of skin cancers. And, skin being the primary site for the synthesis of active form of vitamin D, excessive sun protection could lead to vitamin D-deficient states. But, the results have so far been conflicting. To study the level of awareness, knowledge and attitude of representative groups from the general population from Kuwait towards sun protection. And, also study the correlation of the level of sun protective measures used and vitamin D levels in these groups. The study constituted of two main parts. First part comprised a questionnaire-based survey of representative group of people aged 18 and above to assess their knowledge, awareness and attitude towards sun protection. The second part consisted of measuring serum vitamin D levels in 150 volunteers amongst the responders of the questionnaire, who had been regularly using sunscreens for at least 2 years and compare to the levels seen in 150 age and sex-matched responders of similar skin phototypes, who had never used sunscreens. Out of the total of 1044 responders, 80% of them had adequate knowledge of the beneficial and harmful effects of sun exposure, and had been using sunscreens regularly, and adopting other sun protective measures in their daily life. The levels of vitamin D were found to be deficient in both sunscreen users and those who had never used sunscreens. The difference between the two groups was statistically insignificant (60.67% vs 54.67%; P value>0.001). Population at large seems to be adequately informed about the beneficial and deleterious effects of sun exposure. Vitamin D levels are deficient in majority of our people, and there is a need to do larger surveys covering all parts of the country and give supplemental doses of vitamin D to those
Directory of Open Access Journals (Sweden)
Nawaf Al-Mutairi
2012-01-01
Full Text Available Background: The primary cause of skin cancers is exposure to ultraviolet (UV radiation. And, for decades sun protection has been promoted in various public health education campaigns. Recently, however, vitamin D deficiency has been related to increased risk of skin cancers. And, skin being the primary site for the synthesis of active form of vitamin D, excessive sun protection could lead to vitamin D-deficient states. But, the results have so far been conflicting. Aims: To study the level of awareness, knowledge and attitude of representative groups from the general population from Kuwait towards sun protection. And, also study the correlation of the level of sun protective measures used and vitamin D levels in these groups. Methods: The study constituted of two main parts. First part comprised a questionnaire-based survey of representative group of people aged 18 and above to assess their knowledge, awareness and attitude towards sun protection. The second part consisted of measuring serum vitamin D levels in 150 volunteers amongst the responders of the questionnaire, who had been regularly using sunscreens for at least 2 years and compare to the levels seen in 150 age and sex-matched responders of similar skin phototypes, who had never used sunscreens. Results: Out of the total of 1044 responders, 80% of them had adequate knowledge of the beneficial and harmful effects of sun exposure, and had been using sunscreens regularly, and adopting other sun protective measures in their daily life. The levels of vitamin D were found to be deficient in both sunscreen users and those who had never used sunscreens. The difference between the two groups was statistically insignificant (60.67% vs 54.67%; P value>0.001. Conclusion: Population at large seems to be adequately informed about the beneficial and deleterious effects of sun exposure. Vitamin D levels are deficient in majority of our people, and there is a need to do larger surveys covering all
The genesis of general relativity
Norton, John; Renn, Jürgen; Sauer, Tilman; Stachel, John
2007-01-01
This four-volume work represents the most comprehensive documentation and study of the creation of general relativity; one of the fundamental physical theories of the 20th century. It comprises key sources from Einstein and others who from the late 19th to the early 20th century contributed to this monumental development. Some of these sources are presented here in translation for the first time. Einstein’s famous Zurich notebook, which documents the pivotal steps toward general relativity, is reproduced here for the first time and transcribed in its entirety. The volumes offer detailed commentaries and analyses of these sources that are based on a close reading of these documents supplemented by interpretations by the leading historians of relativity. All in all, the facets of this work, based on more than a decade of research, combine to constitute one of the most in-depth studies of a scientific revolution ever written.
Testing general relativity on accelerators
Directory of Open Access Journals (Sweden)
Tigran Kalaydzhyan
2015-11-01
Full Text Available Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyze experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable – maximal energy of the scattered photons – would experience a significant shift in the ambient gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of resolution and expect our work to be a starting point of further high-precision studies on current and future accelerators, such as PETRA, European XFEL and ILC.
Quantum information and general relativity
International Nuclear Information System (INIS)
Peres, A.
2004-01-01
The Einstein-Podolsky-Rosen paradox (1935) is reexamined in the light of Shannon's information theory (1948). The EPR argument did not take into account that the observers' information was localized, like any other physical object. General relativity introduces new problems: there are horizons which act as on-way membranes for the propagation of quantum information, in particular black holes which act like sinks. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
Quantum information and general relativity
Energy Technology Data Exchange (ETDEWEB)
Peres, A. [Technion, Israel Institute of Technology, Haifa (Israel)
2004-12-01
The Einstein-Podolsky-Rosen paradox (1935) is reexamined in the light of Shannon's information theory (1948). The EPR argument did not take into account that the observers' information was localized, like any other physical object. General relativity introduces new problems: there are horizons which act as on-way membranes for the propagation of quantum information, in particular black holes which act like sinks. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
Quantum information and general relativity
Peres, Asher
2004-01-01
The Einstein-Podolsky-Rosen paradox (1935) is reexamined in the light of Shannon's information theory (1948). The EPR argument did not take into account that the observers' information was localized, like any other physical object. General relativity introduces new problems: there are horizons which act as one-way membranes for the propagation of quantum information, in particular black holes which act like sinks.
Quantum information and general relativity
Peres, A.
2004-11-01
The Einstein-Podolsky-Rosen paradox (1935) is reexamined in the light of Shannon's information theory (1948). The EPR argument did not take into account that the observers' information was localized, like any other physical object. General relativity introduces new problems: there are horizons which act as on-way membranes for the propagation of quantum information, in particular black holes which act like sinks.
Bubble collisions in general relativity
International Nuclear Information System (INIS)
Siklos, S.T.C.; Wu, Z.C.; University of Science and Technology of China, Hofei, Anhwei)
1983-01-01
The collision of two bubbles of true vacuum in a background of false vacuum is considered in the context of General Relativity. It is found that in the thin wall approximation, the problem, can be solved exactly. The region to the future of the collision is described by the pseudo-Schwarzschild de Sitter metric. The parameters in this metric are found by solving the junction conditions at each collision. (author)
Gravitation. [Book on general relativity
Misner, C. W.; Thorne, K. S.; Wheeler, J. A.
1973-01-01
This textbook on gravitation physics (Einstein's general relativity or geometrodynamics) is designed for a rigorous full-year course at the graduate level. The material is presented in two parallel tracks in an attempt to divide key physical ideas from more complex enrichment material to be selected at the discretion of the reader or teacher. The full book is intended to provide competence relative to the laws of physics in flat space-time, Einstein's geometric framework for physics, applications with pulsars and neutron stars, cosmology, the Schwarzschild geometry and gravitational collapse, gravitational waves, experimental tests of Einstein's theory, and mathematical concepts of differential geometry.
Results from Numerical General Relativity
Baker, John G.
2011-01-01
For several years numerical simulations have been revealing the details of general relativity's predictions for the dynamical interactions of merging black holes. I will review what has been learned of the rich phenomenology of these mergers and the resulting gravitational wave signatures. These wave forms provide a potentially observable record of the powerful astronomical events, a central target of gravitational wave astronomy. Asymmetric radiation can produce a thrust on the system which may accelerate the single black hole resulting from the merger to high relative velocity.
A generalized Principle of Relativity
International Nuclear Information System (INIS)
Felice, Fernando de; Preti, Giovanni
2009-01-01
The Theory of Relativity stands as a firm groundstone on which modern physics is founded. In this paper we bring to light an hitherto undisclosed richness of this theory, namely its admitting a consistent reformulation which is able to provide a unified scenario for all kinds of particles, be they lightlike or not. This result hinges on a generalized Principle of Relativity which is intrinsic to Einstein's theory - a fact which went completely unnoticed before. The road leading to this generalization starts, in the very spirit of Relativity, from enhancing full equivalence between the four spacetime directions by requiring full equivalence between the motions along these four spacetime directions as well. So far, no measurable spatial velocity in the direction of the time axis has ever been defined, on the same footing of the usual velocities - the 'space-velocities' - in the local three-space of a given observer. In this paper, we show how Relativity allows such a 'time-velocity' to be defined in a very natural way, for any particle and in any reference frame. As a consequence of this natural definition, it also follows that the time- and space-velocity vectors sum up to define a spacelike 'world-velocity' vector, the modulus of which - the world-velocity - turns out to be equal to the Maxwell's constant c, irrespective of the observer who measures it. This measurable world-velocity (not to be confused with the space-velocities we are used to deal with) therefore represents the speed at which all kinds of particles move in spacetime, according to any observer. As remarked above, the unifying scenario thus emerging is intrinsic to Einstein's Theory; it extends the role traditionally assigned to Maxwell's constant c, and can therefore justly be referred to as 'a generalized Principle of Relativity'.
Paranormal experiences in the general population.
Ross, C A; Joshi, S
1992-06-01
The Dissociative Disorders Interview Schedule was administered to a random sample of 502 adults in the general population of Winnipeg, a midwestern Canadian city. Results showed that paranormal/extrasensory experiences were common in the general population. They were linked to a history of childhood trauma and to other dissociative symptom clusters. A factor analysis of the paranormal experiences identified three factors which together accounted for 44.0% of the combined variance of the scores. A model is proposed in which paranormal experiences are conceptualized as an aspect of normal dissociation. Like dissociation in general, paranormal experiences can be triggered by trauma, especially childhood physical or sexual abuse. Such experiences discriminate individuals with childhood trauma histories from those without at high levels of significance.
Modern Canonical Quantum General Relativity
Thiemann, Thomas
2008-11-01
Preface; Notation and conventions; Introduction; Part I. Classical Foundations, Interpretation and the Canonical Quantisation Programme: 1. Classical Hamiltonian formulation of general relativity; 2. The problem of time, locality and the interpretation of quantum mechanics; 3. The programme of canonical quantisation; 4. The new canonical variables of Ashtekar for general relativity; Part II. Foundations of Modern Canonical Quantum General Relativity: 5. Introduction; 6. Step I: the holonomy-flux algebra [P]; 7. Step II: quantum-algebra; 8. Step III: representation theory of [A]; 9. Step IV: 1. Implementation and solution of the kinematical constraints; 10. Step V: 2. Implementation and solution of the Hamiltonian constraint; 11. Step VI: semiclassical analysis; Part III. Physical Applications: 12. Extension to standard matter; 13. Kinematical geometrical operators; 14. Spin foam models; 15. Quantum black hole physics; 16. Applications to particle physics and quantum cosmology; 17. Loop quantum gravity phenomenology; Part IV. Mathematical Tools and their Connection to Physics: 18. Tools from general topology; 19. Differential, Riemannian, symplectic and complex geometry; 20. Semianalytical category; 21. Elements of fibre bundle theory; 22. Holonomies on non-trivial fibre bundles; 23. Geometric quantisation; 24. The Dirac algorithm for field theories with constraints; 25. Tools from measure theory; 26. Elementary introduction to Gel'fand theory for Abelean C* algebras; 27. Bohr compactification of the real line; 28. Operatir -algebras and spectral theorem; 29. Refined algebraic quantisation (RAQ) and direct integral decomposition (DID); 30. Basics of harmonic analysis on compact Lie groups; 31. Spin network functions for SU(2); 32. + Functional analytical description of classical connection dynamics; Bibliography; Index.
Homothetic motions in general relativity
International Nuclear Information System (INIS)
McIntosh, C.B.G.
1976-01-01
Properties of homothetic or self-similar motions in general relativity are examined with particular reference to vacuum and perfect-fluid space-times. The role of the homothetic bivector with components Hsub((a;b)) formed from the homothetic vector H is discussed in some detail. It is proved that a vacuum space-time only admits a nontrivial homothetic motion if the homothetic vector field is non-null and is not hypersurface orthogonal. As a subcase of a more general result it is shown that a perfect-fluid space-time cannot admit a non-trivial homothetic vector which is orthogonal to the fluid velocity 4-vector. (author)
Einstein algebras and general relativity
International Nuclear Information System (INIS)
Heller, M.
1992-01-01
A purely algebraic structure called an Einstein algebra is defined in such a way that every spacetime satisfying Einstein's equations is an Einstein algebra but not vice versa. The Gelfand representation of Einstein algebras is defined, and two of its subrepresentations are discussed. One of them is equivalent to the global formulation of the standard theory of general relativity; the other one leads to a more general theory of gravitation which, in particular, includes so-called regular singularities. In order to include other types of singularities one must change to sheaves of Einstein algebras. They are defined and briefly discussed. As a test of the proposed method, the sheaf of Einstein algebras corresponding to the space-time of a straight cosmic string with quasiregular singularity is constructed. 22 refs
General relativity and gravitation, 1989
International Nuclear Information System (INIS)
Ashby, N.; Bartlett, D.F.; Wyss, W.
1990-01-01
This volume records the lectures and symposia of the 12th International Conference on General Relativity and Gravitation. Plenary lecturers reviewed the major advances since the previous conference in 1986. The reviews cover classical and quantum theory of gravity, colliding gravitational waves, gravitational lensing, relativistic effects on pulsars, tests of the inverse square law, numerical relativity, cosmic microwave background radiation, experimental tests of gravity theory, gravitational wave detectors, and cosmology. The plenary lectures are complemented by summaries of symposia, provided by the chairmen. Almost 700 contributed papers were presented at these and they cover an even wider range of topics than the plenary talks. The book provides a comprehensive guide to research activity in both experimental and theoretical gravitation and its applications in astrophysics and cosmology. It will be essential reading for research workers in these fields, as well as theoretical and experimental physicists, astronomers, and mathematicians who wish to be acquainted with modern developments in gravitational theory and general relativity. All the papers and summaries of the workshop sessions are indexed separately. (16 united talks, 20 workshop sessions). (author)
Characteristics of hyperacusis in the general population
Directory of Open Access Journals (Sweden)
Johan Paulin
2016-01-01
Full Text Available There is a need for better understanding of various characteristics in hyperacusis in the general population. The objectives of the present study were to investigate individuals in the general population with hyperacusis regarding demographics, lifestyle, perceived general health and hearing ability, hyperacusis-specific characteristics and behavior, and comorbidity. Using data from a large-scale population-based questionnaire study, we investigated individuals with physician-diagnosed (n = 66 and self-reported (n = 313 hyperacusis in comparison to individuals without hyperacusis (n = 2995. High age, female sex, and high education were associated with hyperacusis, and that trying to avoid sound sources, being able to affect the sound environment, and having sough medical attention were common reactions and behaviors. Posttraumatic stress disorder, chronic fatigue syndrome, generalized anxiety disorder, depression, exhaustion, fibromyalgia, irritable bowel syndrome, migraine, hearing impairment, tinnitus, and back/joint/muscle disorders were comorbid with hyperacusis. The results provide ground for future study of these characteristic features being risk factors for development of hyperacusis and/or consequences of hyperacusis.
Population cycles: generalities, exceptions and remaining mysteries
2018-01-01
Population cycles are one of nature's great mysteries. For almost a hundred years, innumerable studies have probed the causes of cyclic dynamics in snowshoe hares, voles and lemmings, forest Lepidoptera and grouse. Even though cyclic species have very different life histories, similarities in mechanisms related to their dynamics are apparent. In addition to high reproductive rates and density-related mortality from predators, pathogens or parasitoids, other characteristics include transgenerational reduced reproduction and dispersal with increasing-peak densities, and genetic similarity among populations. Experiments to stop cyclic dynamics and comparisons of cyclic and noncyclic populations provide some understanding but both reproduction and mortality must be considered. What determines variation in amplitude and periodicity of population outbreaks remains a mystery. PMID:29563267
Nonlinear generalization of special relativity
International Nuclear Information System (INIS)
Winterberg, F.
1985-01-01
In Poincares axiomatic formulation special relativity is a derived consequence of a true Lorentz contraction, for a rod in absolute motion through a substratum. Furthermore, Lorentz had shown that the rod contraction can be understood by an inverse square law interaction and therefore special relativity derived from more fundamental principles. The derivation by Lorentz shows that the root of the divergence problems is the singular inverse square law. By replacing the inverse square law with a regular one through the introduction of a finite length, the author has succeeded in deriving a nonlinear generalization of special relativity which eliminates all infinities. Besides the relative velocities, these nonlinear transformation equations also contain absolute velocities against a substratum, but in the limit of small energies they go over into the linear Lorentz transformations. Depending on the smallness of the fundamental length, departures from special relativity can be observed only at very high energies. The theorem that the velocity of light is the same in all reference systems still holds and likewise the conservation laws for energy and momentum
Relativity: Special, General, and Cosmological
International Nuclear Information System (INIS)
Ellis, G F R
2005-01-01
Wolfgang Rindler is known as a writer of exceptional clarity. This quality is evident in this book as it explores in depth first special relativity, then general relativity, and finally relativistic cosmology. He bases his writing in the fundamental underlying ideas and principles that so successfully guided Einstein in his work, clarifying their nature and implications in an illuminating way with many examples. The usual suspects are there: the relativity principle and equivalence principle, the abolishing of absolute space, invariance of the speed of light, analytic and geometric representations of the Lorentz transformation, its kinematic and dynamic consequences, relativistic optics, Minkowski spacetime, energy and momentum conservation, and the Compton effect. Particularly useful is the emphasis on the unity of the whole: for example (p 63) that the kinematic effect of length shortening must imply a corresponding detailed mechanical explanation of that shortening. The tensor formulation of Maxwell's equations leads to the transformation properties of the electromagnetic field and consequent elegant derivation of the field of an infinite straight current; in this case, relativity is important even for slowly moving charges because an ordinary current moves a very big charge (p 151). General relativity is systematically introduced in stages, starting with curved spaces and moving on through static and stationary spacetimes, geodesics, and tensor calculus to the field equations. A considerable strength of the book is the careful detailed examination of the local and global geometry of the major significant solutions of the equations: the Schwarzschild spacetime and its Kruskal extension, plane gravitational waves, de sitter and anti-de Sitter spacetimes, and Robertson-Walker cosmologies. The latter includes a clear presentation of the dust and radiation model dynamics for the variety of possible cases, a detailed examination of observational relations, and
The renaissance of general relativity
International Nuclear Information System (INIS)
Will, C.
1989-01-01
A historical evaluation of Einstein's theory of general relativity is presented, including the three classical tests of the theory. Gravitation is shown to be a ''curved spacetime'' phenomenon, particularly if the Einstein equivalence principle (EEP) is true. The article traces the success and failures of the theory over the years and up to the present. The concept of gravitation waves was, for example, strengthened by the discovery of a binary pulsar in 1974. The author describes the theory's relevance to neutron stars and black holes and its role in establishing the hot big bang model of cosmological evolution. The article concludes by considering the possibility of antigravity and how gravitational calculations can be done by computer because of the large number of variables in the calculations. (U.K.)
General relativity: An erfc metric
Plamondon, Réjean
2018-06-01
This paper proposes an erfc potential to incorporate in a symmetric metric. One key feature of this model is that it relies on the existence of an intrinsic physical constant σ, a star-specific proper length that scales all its surroundings. Based thereon, the new metric is used to study the space-time geometry of a static symmetric massive object, as seen from its interior. The analytical solutions to the Einstein equation are presented, highlighting the absence of singularities and discontinuities in such a model. The geodesics are derived in their second- and first-order differential formats. Recalling the slight impact of the new model on the classical general relativity tests in the solar system, a number of facts and open problems are briefly revisited on the basis of a heuristic definition of σ. A special attention is given to gravitational collapses and non-singular black holes.
Spacecraft Tests of General Relativity
Anderson, John D.
1997-01-01
Current spacecraft tests of general relativity depend on coherent radio tracking referred to atomic frequency standards at the ground stations. This paper addresses the possibility of improved tests using essentially the current system, but with the added possibility of a space-borne atomic clock. Outside of the obvious measurement of the gravitational frequency shift of the spacecraft clock, a successor to the suborbital flight of a Scout D rocket in 1976 (GP-A Project), other metric tests would benefit most directly by a possible improved sensitivity for the reduced coherent data. For purposes of illustration, two possible missions are discussed. The first is a highly eccentric Earth orbiter, and the second a solar-conjunction experiment to measure the Shapiro time delay using coherent Doppler data instead of the conventional ranging modulation.
Machian effects in general relativity
International Nuclear Information System (INIS)
Embacher, F.
1988-01-01
As a consequence of Mach's principle, rotating matter should cause local inertial frames or gyroscopes in its vicinity to undergo a small rotation which is not present in the Newtonian picture. H. Thirring and J. Lense were the first to derive similar predictions from the field equations of general relativity. Since these early days of relativity, a lot of exact and approximate solutions to Einstein's equations have been examined under this point of view. The qualitative features of Machian effects are most easily demonstrated in the cylinder symmetric case, where some exact results are available. For example, space-time is flat inside a uniformly rotating matter shell, and the rotation of this interior with respect to 'infinity' (the distant stars) has a clear meaning. In the more realistic case of what happens near a massive rotating star, one is forced to perform certain approximations. In modern language, Machian effects are described in terms of the twist of timelike killing vector fields. In the linearized theory, the equations that determine the Machian structure generated by a given matter distribution, resemble to some extent those of classical electrodynamics. This correspondence provides a pedagogical approach how to compute the quantitative extent of inertial frame 'dragging'. 6 refs., 5 figs. (Author)
Angular momentum in general relativity
International Nuclear Information System (INIS)
Prior, C.R.
1977-01-01
The definition of angular momentum proposed in part I of this series (Prior. Proc. R. Soc. Lond.; A354:379 (1977)) is investigated when applied to rotating black holes. It is shown how to use the formula to evaluate the angular momentum of a stationary black hole. This acts as a description of a background space on which the effect of first matter and then gravitational perturbations is considered. The latter are of most interest and the rate of change of angular momentum, dJ/dt, is found as an expression in the shear induced in the event horizon by the perturbation and in its time integral. Teukolsky's solutions (Astrophys. J.; 185:635 (1973)) for the perturbed component of the Weyl tensor are then used to find this shear and hence to give an exact answer for dJ/dt. One of the implications of the result is a direct verification of Bekenstein's formula (Phys. Rev.; 7D:949 (1973)) relating in a simple way the rate of change of angular momentum to the rate of change of mass caused by a plane wave. A more general expression is also given for dM/dt. Considering only stationary perturbations, it is shown how to generalize the definition of angular momentum so as to include information about its direction as well. Three problems are particularly discussed - a single moon, two or more moons and a ring of matter causing the perturbation - since they provide illustrations of all the main features of the black hole's behaviour. In every case it is found that the black hole realigns its axis of rotation so that the final configuration is axisymmetric if possible; otherwise is slows down completely to reach a static state. (author)
Gambling Problems in the General Danish Population
DEFF Research Database (Denmark)
Harrison, Glenn W.; Jessen, Lasse J.; Lau, Morten
We compare several popular survey instruments for measuring gambling behavior and gambling propensity to assess if they differ in their classification of individuals in the general adult Danish population. We also examine correlations with standard survey instruments for alcohol use, anxiety......, depression and impulsivity. A feature of our design is that nobody was excluded on the basis of their response to a “trigger,” “gateway” or “diagnostic item” question about previous gambling history. Our sample consists of 8,405 adult Danes. We administered the Focal Adult Gambling Screen to all subjects...... and estimate prevalence of gambling problems using sample weights and controlling for sample selection. We find that 95.4% of the population has no detectable risk, 2.9% has an early risk, 0.8% has an intermediate risk, 0.7% has an advanced risk, and 0.2% can be classified as problem gamblers...
Geometric quantization and general relativity
International Nuclear Information System (INIS)
Souriau, J.-M.
1977-01-01
The purpose of geometric quantization is to give a rigorous mathematical content to the 'correspondence principle' between classical and quantum mechanics. The main tools are borrowed on one hand from differential geometry and topology (differential manifolds, differential forms, fiber bundles, homology and cohomology, homotopy), on the other hand from analysis (functions of positive type, infinite dimensional group representations, pseudo-differential operators). Some satisfactory results have been obtained in the study of dynamical systems, but some fundamental questions are still waiting for an answer. The 'geometric quantization of fields', where some further well known difficulties arise, is still in a preliminary stage. In particular, the geometric quantization on the gravitational field is still a mere project. The situation is even more uncertain due to the fact that there is no experimental evidence of any quantum gravitational effect which could give us a hint towards what we are supposed to look for. The first level of both Quantum Theory, and General Relativity describes passive matter: influence by the field without being a source of it (first quantization and equivalence principle respectively). In both cases this is only an approximation (matter is always a source). But this approximation turns out to be the least uncertain part of the description, because on one hand the first quantization avoids the problems of renormalization and on the other hand the equivalence principle does not imply any choice of field equations (it is known that one can modify Einstein equations at short distances without changing their geometrical properties). (Auth.)
Alfimova, M V; Uvarova, L G
2007-01-01
To search for EEG-correlates of emotional processing that might be indicators of genetic predisposition to schizophrenia, changes in EEG spectral power during perception of neutral and emotionally salient words were examined in 36 schizophrenic patients, 50 of their unaffected first-degree relatives, and 47 healthy individuals without any family history of psychoses. In healthy persons, passive listening to neutral words induced minimum changes in cortical rhythmical activity, predominantly in the form of synchronization of slow and fast waves, whereas perception of emotional words was followed by a generalized depression of the alpha and beta1 activity and a locally specific decrease in the power of theta and beta2 frequency bands. The patients and their relatives showed a decrease in the alpha and beta1 activity simultaneously with an increase in the power of delta activity in response to both groups of words. Thus, in the patients and their relatives, reactions to neutral and emotional words were ulterior as a result of augmented reactions to the neutral words. These findings suggest that the EEG changes reflect familial and possibly hereditable abnormal involuntary attention. No prominent decrease in reactivity to emotional stimuli was revealed in schizophrenic families.
Alfimova, M V; Uvarova, L G
2008-06-01
EEG correlates of impairments in the processing of emotiogenic information which might reflect a genetic predisposition to schizophrenia were sought by studying the dynamics of EEG rhythm powers on presentation of neutral and emotional words in 36 patients with schizophrenia, 50 of their unaffected first-degree relatives, and 47 healthy subjects without any inherited predisposition to psychoses. In controls, passive hearing of neutral words produced minimal changes in cortical rhythms, predominantly in the form of increases in the power levels of slow and fast waves, while perception of emotional words was accompanied by generalized reductions in the power of the alpha and beta(1) rhythms and regionally specific suppression of theta and beta(2) activity. Patients and their relatives demonstrated reductions in power of alpha and beta(1) activity, with an increase in delta power on hearing both groups of words. Thus, differences in responses to neutral and emotional words in patients and their relatives were weaker, because of increased reactions to neutral words. These results may identify EEG reflections of pathology of involuntary attention, which is familial and, evidently, inherited in nature. No reduction in reactions to emotiogenic stimuli was seen in patients' families.
International Nuclear Information System (INIS)
Honjo, Satoshi; Ando, Jiro; Tsukioka, Takeo
2007-01-01
Breast cancer screening by mammography is thought to be effective in reducing breast cancer mortality while ultrasonography is not accepted as a population screening modality, although the latter has been suggested to be useful in detection of cancer in the dense breast, relatively more typical for a younger woman. Mammography with medio-lateral oblique view was offered on trial in 1999-2000 for 3453 female residents in Tochigi prefecture who also underwent clinical breast examination and ultrasonography. The municipalities that provided cancer screening were informed of the final diagnosis for women with positive findings in the screening trial by doctors who performed the diagnostic evaluation. Linkage was also made between the list of participants in the trial and registrations at Tochigi Cancer Registry for breast cancer cases diagnosed during 1999-2001. Thirteen cases with breast cancer were identified during a 2-year follow-up period: 10 were diagnosed subsequent to positive finding in the trial; two were negative in the trial and diagnosed 23 and 24 months after, respectively; and one had a positive finding at the trial but was undiagnosed at first and then diagnosed 18 months after the trial. Among the 11 cases judged as positive in the trial, four were judged only by mammography while three were judged only by ultrasonography. Those mammography alone-detected cases were relatively young, at 36, 40, 47 and 54 years of age, respectively, while the ultrasonography alone-detected cases were aged 50, 55 and 68, respectively. Combined screening with mammography and ultrasonography may be feasible. A larger study is required to evaluate relative performance of mammography and ultrasonography in detail by characteristics of examinees and their breasts. (author)
Modern Canonical Quantum General Relativity;
International Nuclear Information System (INIS)
Kiefer, Claus
2008-01-01
The open problem of constructing a consistent and experimentally tested quantum theory of the gravitational field has its place at the heart of fundamental physics. The main approaches can be roughly divided into two classes: either one seeks a unified quantum framework of all interactions or one starts with a direct quantization of general relativity. In the first class, string theory (M-theory) is the only known example. In the second class, one can make an additional methodological distinction: while covariant approaches such as path-integral quantization use the four-dimensional metric as an essential ingredient of their formalism, canonical approaches start with a foliation of spacetime into spacelike hypersurfaces in order to arrive at a Hamiltonian formulation. The present book is devoted to one of the canonical approaches-loop quantum gravity. It is named modern canonical quantum general relativity by the author because it uses connections and holonomies as central variables, which are analogous to the variables used in Yang-Mills theories. In fact, the canonically conjugate variables are a holonomy of a connection and the flux of a non-Abelian electric field. This has to be contrasted with the older geometrodynamical approach in which the metric of three-dimensional space and the second fundamental form are the fundamental entities, an approach which is still actively being pursued. It is the author's ambition to present loop quantum gravity in a way in which every step is formulated in a mathematically rigorous form. The formal Leitmotiv of loop quantum gravity is background independence. Non-gravitational theories are usually quantized on a given non-dynamical background. In contrast, due to the geometrical nature of gravity, no such background exists in quantum gravity. Instead, the notion of a background is supposed to emerge a posteriori as an approximate notion from quantum states of geometry. As a consequence, the standard ultraviolet divergences of
Sleep and psychopatholgy : in the general population and bipolar disorder
Verkooijen, Susanne
2017-01-01
This thesis set out to investigate the relation between sleep and psychopathology. We examined two groups; bipolar patients and adolescents from the general population that are both characterized by mood fluctuations and are vulnerable for disturbances in sleep-wake pattern. Using wearables
Zhu, Yanbo; Wang, Qi; Pang, Guoming; Lin, Lin; Origasa, Hideki; Wang, Yangyang; Di, Jie; Shi, Mai; Fan, Chunpok; Shi, Huimei
2015-01-01
There was no consistent recognition of the association between high or low body mass index (BMI) and health related quality of life (HRQL). The aim of this research was to study the association between BMI and HRQL in Chinese adults, and to further explore the stability of that association in the subgroup analysis stratified by status of chronic conditions. A total of 21,218 adults aged 18 and older were classified as underweight, normal weight, overweight, class I obese, and class II obese based on their BMI. HRQL was measured by the SF-36 Health Survey. The independent impact of each BMI category on HRQL was examined through standard least squares regression by comparing the difference of SF-36 scores and the minimum clinically important differences (MCID), which was defined as 3 points. Compared to the normal weight, the class I obese was significantly associated with better HRQL scores in the mental component summary (MCS) (75.1 vs. 73.4, Pobese (D=-3.43) and the general health for the underweight (D=-3.71). Stratified analyses showed a similar result in the health subjects and chronic conditions, and it was significant in the chronic conditions. The class I obese showed the best HRQL, especially in the mental domain. The worst HRQL was found in the underweight. The class II obese reduced HRQL in the physical functioning only. "Obesity paradox" was more obvious in the participants with chronic conditions.
Alexithymia in the German general population.
Franz, Matthias; Popp, Kerstin; Schaefer, Ralf; Sitte, Wolfgang; Schneider, Christine; Hardt, Jochen; Decker, Oliver; Braehler, Elmar
2008-01-01
The Toronto-Alexithymia-Scale (TAS-20) is used worldwide as a valid measurement of alexithymia. Until now, population-based standardization and cut-off values of the German TAS-20 version have not been available. This study provides these by means of a representative German sample and by investigating the factorial structure of the TAS-20. Data were generated from a representative random sample of the German general population (1,859 subjects aged between 20 and 69). The TAS-20 sum score was normally distributed. The mean value was 49.5 (SD=9.3) in men and 48.2 (SD=9.2) in women. Divorce, single and low social status were associated with enhanced sum scores. Ten percent of the population exceeded the TAS-20 sum score threshold of >or=61. The 66th percentile reached 53 for men and 52 for women. Factor analysis identified three factors that match the scales of the English original version. An additional fourth factor ("importance of emotional introspection") was extracted. Total explanation of variance by these four factors was 52.27%. The sum score of the German TAS-20 version is suited for the standardized measure of alexithymia. For selecting alexithymic individuals in experimental studies, the cut-off >or=61 is possibly too restrictive. Therefore, we propose the 66th percentile for the identification of high alexithymics. The TAS-20 sum score is associated with important socio-demographic variables. The factorial structure is reliable; the fourth factor ("importance of emotional introspection") provides differentiation of content and allows for enhanced explanation of variance.
Action principle for the generalized harmonic formulation of general relativity
International Nuclear Information System (INIS)
Brown, J. David
2011-01-01
An action principle for the generalized harmonic formulation of general relativity is presented. The action is a functional of the spacetime metric and the gauge source vector. An action principle for the Z4 formulation of general relativity has been proposed recently by Bona, Bona-Casas, and Palenzuela. The relationship between the generalized harmonic action and the Bona, Bona-Casas, and Palenzuela action is discussed in detail.
Directory of Open Access Journals (Sweden)
Yanbo Zhu
Full Text Available There was no consistent recognition of the association between high or low body mass index (BMI and health related quality of life (HRQL. The aim of this research was to study the association between BMI and HRQL in Chinese adults, and to further explore the stability of that association in the subgroup analysis stratified by status of chronic conditions.A total of 21,218 adults aged 18 and older were classified as underweight, normal weight, overweight, class I obese, and class II obese based on their BMI. HRQL was measured by the SF-36 Health Survey. The independent impact of each BMI category on HRQL was examined through standard least squares regression by comparing the difference of SF-36 scores and the minimum clinically important differences (MCID, which was defined as 3 points.Compared to the normal weight, the class I obese was significantly associated with better HRQL scores in the mental component summary (MCS (75.1 vs. 73.4, P<0.001. The underweight had the lowest score in both the physical components summary (PCS (75.4 vs. 77.5, P<0.001 and mental components summary (MCS (71.8 vs. 73.4, P<0.001. For the MCID, the HRQL score was reduced by more than 3 points in the physical functioning for the class II obese (D=-3.43 and the general health for the underweight (D=-3.71. Stratified analyses showed a similar result in the health subjects and chronic conditions, and it was significant in the chronic conditions.The class I obese showed the best HRQL, especially in the mental domain. The worst HRQL was found in the underweight. The class II obese reduced HRQL in the physical functioning only. "Obesity paradox" was more obvious in the participants with chronic conditions.
Zorn algebra in general relativity
International Nuclear Information System (INIS)
Oliveira, C.G.; Maia, M.D.
The covariant differential properties of the split Cayley subalgebra of local real quaternion tetrads is considered. Referred to this local quaternion tetrad several geometrical objects are given in terms of Zorn-Weyl matrices. Associated to a pair of real null vectors we define two-component spinor fields over the curved space and the associated Zorn-Weyl matrices which satisfy the Dirac equation written in terms of the Zorn algebra. The formalism is generalized by considering a field of complex tetrads defining a Hermitian second rank tensor. The real part of this tensor describes the gravitational potentials and the imaginary part the electromagnetic potentials in the Lorentz gauge. The motion of a charged spin zero test body is considered. The Zorn-Weyl algebra associated to this generalized formalism has elements belonging to the full octonion algebra [pt
Isotropic stars in general relativity
International Nuclear Information System (INIS)
Mak, M.K.; Harko, T.
2013-01-01
We present a general solution of the Einstein gravitational field equations for the static spherically symmetric gravitational interior space-time of an isotropic fluid sphere. The solution is obtained by transforming the pressure isotropy condition, a second order ordinary differential equation, into a Riccati type first order differential equation, and using a general integrability condition for the Riccati equation. This allows us to obtain an exact non-singular solution of the interior field equations for a fluid sphere, expressed in the form of infinite power series. The physical features of the solution are studied in detail numerically by cutting the infinite series expansions, and restricting our numerical analysis by taking into account only n=21 terms in the power series representations of the relevant astrophysical parameters. In the present model all physical quantities (density, pressure, speed of sound etc.) are finite at the center of the sphere. The physical behavior of the solution essentially depends on the equation of state of the dense matter at the center of the star. The stability properties of the model are also analyzed in detail for a number of central equations of state, and it is shown that it is stable with respect to the radial adiabatic perturbations. The astrophysical analysis indicates that this solution can be used as a realistic model for static general relativistic high density objects, like neutron stars. (orig.)
Working situation of cancer survivors versus the general population.
Lee, Myung Kyung; Yun, Young Ho
2015-06-01
The purposes of this study were to compare the working situation of cancer survivors and the general (cancer-free) population and investigate characteristics associated with the increased likelihood of unemployment between the two groups. We selected 1927 cancer survivors from the 2008 Korean Community Health Survey data less than 65 years of age and used propensity score matching to randomly select 1924 individuals from the general population who closely resembled the cancer survivors. Compared to the general population, cancer survivors were less likely to be engaged in paid work, particularly as permanent workers, and were more likely to work regular hours. Additionally, they tended to do less work that involved lifting or moving heavy objects and uncomfortable postures and were more willing to express their emotions. An increased probability of unemployment among cancer survivors was associated with being over 50 years old, being female, having a lower monthly income, having multiple comorbidities, belonging to a nuclear family, being a National Basic Livelihood Act beneficiary, and having a recent diagnosis. Cancer survivors may want to pursue flexible occupations and improve their working situation. Further, they perceive their workplace more positively compared to the general population. Respecting the cancer survivor's choice to find flexible working conditions that suit their health needs and status, health-care providers involved in managing work-related issues among cancer survivors should be aware of the interaction between work-related concerns and post-cancer disease management.
Numerical Hydrodynamics in General Relativity
Directory of Open Access Journals (Sweden)
Font José A.
2003-01-01
Full Text Available The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article, the present update provides additional information on numerical schemes, and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes, and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.
DEFF Research Database (Denmark)
Søholm, Helle; Kjaergaard, Jesper; Thomsen, Jakob Hartvig
2014-01-01
-athletic population. METHODS: Consecutive patients with OHCA were admitted with return of spontaneous circulation (ROSC) or on-going resuscitation at hospital arrival (2002-2011). Patient charts were reviewed for post-resuscitation data. Exercise was defined as moderate/vigorous physical activity. RESULTS: A total...
Behavior in the General Population in Italy
Directory of Open Access Journals (Sweden)
Luisa Maria Roberta Tedesco
2015-01-01
Full Text Available Background. The objectives of the study were to document knowledge, attitudes, and behaviors of women regarding cardiovascular diseases (CVDs and the determinants associated. Materials and Methods. The cross-sectional survey was conducted among a random sample of 830 women older than 18 years from the general population in Italy. Results. Almost all participants reported having heard about CVDs, and among them 89.4% and 74.7% identified smoking and high cholesterol level as risk factors. Only 26.5% identified the main CVDs risk factors. Women more knowledgeable were married and better educated and self-perceived a worse health status. Only 23% knew the main CVDs preventive measures and this knowledge was significantly higher in women who are unemployed, who are more educated, who have received information about CVDs from physicians, and who know the main risk factors. Respondents with lower education, those with at least three children, those who self-perceived a worse health status, and those who need information were most likely to have a positive attitude toward the perceived risk of developing CVDs. Women with two or three children or more were at high risk profiles 49% and 56% lower than women with one child. Conclusions. Educational programs are needed among women as support to improve knowledge and appropriate behavior about CVDs.
Stochastic quantization of general relativity
International Nuclear Information System (INIS)
Rumpf, H.
1986-01-01
Following an elementary exposition of the basic mathematical concepts used in the theory of stochastic relaxation processes the stochastic quantization method of Parisi and Wu is briefly reviewed. The method is applied to Einstein's theory of gravitation using a formalism that is manifestly covariant with respect to field redefinitions. This requires the adoption of Ito's calculus and the introduction of a metric in field configuration space, for which there is a unique candidate. Due to the indefiniteness of the Euclidean Einstein-Hilbert action stochastic quantization is generalized to the pseudo-Riemannian case. It is formally shown to imply the DeWitt path integral measure. Finally a new type of perturbation theory is developed. (Author)
A logic road from special relativity to general relativity
Andréka, Hajnal; Madarász, Judit X.; Németi, István; Székely, Gergely
2010-01-01
We present a streamlined axiom system of special relativity in first-order logic. From this axiom system we "derive" an axiom system of general relativity in two natural steps. We will also see how the axioms of special relativity transform into those of general relativity. This way we hope to make general relativity more accessible for the non-specialist.
Quantifying tone deafness in the general population.
Sloboda, John A; Wise, Karen J; Peretz, Isabelle
2005-12-01
the general population, whose purpose is to discriminate "true" from "false" amusics. Such discrimination is essential to achieve a better understanding of the variety of causes of low musical achievement.
Conformal methods in general relativity
Valiente Kroon, Juan A
2016-01-01
This book offers a systematic exposition of conformal methods and how they can be used to study the global properties of solutions to the equations of Einstein's theory of gravity. It shows that combining these ideas with differential geometry can elucidate the existence and stability of the basic solutions of the theory. Introducing the differential geometric, spinorial and PDE background required to gain a deep understanding of conformal methods, this text provides an accessible account of key results in mathematical relativity over the last thirty years, including the stability of de Sitter and Minkowski spacetimes. For graduate students and researchers, this self-contained account includes useful visual models to help the reader grasp abstract concepts and a list of further reading, making this the perfect reference companion on the topic.
Pulsar timing and general relativity
Backer, D. C.; Hellings, R. W.
1986-01-01
Techniques are described for accounting for relativistic effects in the analysis of pulsar signals. Design features of instrumentation used to achieve millisecond accuracy in the signal measurements are discussed. The accuracy of the data permits modeling the pulsar physical characteristics from the natural glitches in the emissions. Relativistic corrections are defined for adjusting for differences between the pulsar motion in its spacetime coordinate system relative to the terrestrial coordinate system, the earth's motion, and the gravitational potentials of solar system bodies. Modifications of the model to allow for a binary pulsar system are outlined, including treatment of the system as a point mass. Finally, a quadrupole model is presented for gravitational radiation and techniques are defined for using pulsars in the search for gravitational waves.
The use of generalized functions and distributions in general relativity
International Nuclear Information System (INIS)
Steinbauer, R; Vickers, J A
2006-01-01
We review the extent to which one can use classical distribution theory in describing solutions of Einstein's equations. We show that there are a number of physically interesting cases which cannot be treated using distribution theory but require a more general concept. We describe a mathematical theory of nonlinear generalized functions based on Colombeau algebras and show how this may be applied in general relativity. We end by discussing the concept of singularity in general relativity and show that certain solutions with weak singularities may be regarded as distributional solutions of Einstein's equations. (topical review)
Chan, Brian T; Tsai, Alexander C
2017-01-11
HIV-related stigma hampers treatment and prevention efforts worldwide. Effective interventions to counter HIV-related stigma are greatly needed. Although the "contact hypothesis" suggests that personal contact with persons living with HIV (PLHIV) may reduce stigmatizing attitudes in the general population, empirical evidence in support of this hypothesis is lacking. Our aim was to estimate the association between personal contact with PLHIV and HIV-related stigma among the general population of sub-Saharan Africa. Social distance and anticipated stigma were operationalized using standard HIV-related stigma questions contained in the Demographic and Health Surveys and AIDS Indicator Surveys of 26 African countries between 2003 and 2008. We fitted multivariable logistic regression models with country-level fixed effects, specifying social distance as the dependent variable and personal contact with PLHIV as the primary explanatory variable of interest. We analyzed data from 206,717 women and 91,549 men living in 26 sub-Saharan African countries. We estimated a statistically significant negative association between personal contact with PLHIV and desires for social distance (adjusted odds ratio [AOR] = 0.80; p interventions should be developed and tested to reduce the stigma of HIV.
Patton, Kiri A.; Ware, Robert; McPherson, Lyn; Emerson, Eric; Lennox, Nicholas
2018-01-01
Background: Carers of children with intellectual disability show high rates of parent-related stress and are at an increased risk for deleterious physical and mental health. Materials and Methods: This study investigated the relationship between demographic and social characteristics and parenting stress, within two different cross-sectional…
Jacobs, E.M.G.; Hendriks, J.C.M.; Marx, J.J.M.; Deursen, C.T. van; Kreeftenberg, H.G.; Vries, R.A. de; Stalenhoef, A.F.H.; Verbeek, A.L.M.; Swinkels, D.W.
2007-01-01
BACKGROUND: Family screening has been suggested as a sophisticated model for the early detection of HFE-related hereditary haemochromatosis (HH). However, until now, controlled studies on the morbidity and mortality in families with HH are lacking. METHODS: Data on iron parameters, morbidity and
van Hateren, K.J.J.; Kleefstra, N.; Groenier, K.H.; Gans, R.O.B.; Bilo, H.J.G.; Landman, G.
2010-01-01
OBJECTIVE- Diabetes negatively impacts the health-related quality of life (HRQOL) of patients with type 2 diabetes. An earlier analysis showed HRQOL to be associated with mortality, which suggests that measuring HRQOL could have clinical implications. We studied the association between HRQOL and
General relativity and mathematics; Relatividad General y Matematicas
Energy Technology Data Exchange (ETDEWEB)
Mars, M.
2015-07-01
General relativity is more than a theory of gravity, since any physical process occupies space and lasts for a time, forcing to reconcile that physical theory that describes what the dynamic nature of space-time itself. (Author)
General considerations on the population ageing
Directory of Open Access Journals (Sweden)
Alina Nuta
2016-05-01
Full Text Available This article presents one of the most important issues of the current context, the ageing of the population, with major consequences on the financial stability of the nation. This restructure of the population (that change the shape of the population pyramid , as a result, on the one hand, of the reducing in the fertility rate, on the other hand, increasing in life expectancy and last but not least, due to migration, unbalance national budgets, generating negative effects in economic, financial and social terms.
Directory of Open Access Journals (Sweden)
Huikuan Chu
2014-01-01
Full Text Available Objective. To acquire more data about the epidemiologic characteristics of constipation in different kinds of populations in China. Methods. Using “constipation” and “China” as search terms; relevant papers were searched from January 1995 to April 2014. Data on prevalence, gender, diagnostic criteria, geographical area, educational class, age, race, and physician visit results were extracted and analyzed. Results. 36 trials were included. Prevalence rates of constipation in elderly population (18.1% and pediatric population (18.8% were significantly higher than that in general population (8.2%. Prevalence of constipation defined by non-Rome criteria was higher than that by Rome criteria in general population. Prevalence rates of constipation were different for different geographical area. People with less education were predisposed to constipation. In pediatric population, prevalence of constipation was the lowest in children aged 2–6 years. Prevalence of constipation in ethnic minorities was higher than that in Han people. People with constipation were predisposed to FD, haemorrhoid, and GERD. Only 22.2% patients seek medical advice in general population. Conclusions. In China, prevalence of constipation was lower compared with most of other countries. The factors including female gender, diagnostic criteria, geographical area, age, educational class, and race seemed to have major effects on prevalence of constipation.
Centennial of general relativity a celebration
2017-01-01
It has been over 100 years since the presentation of the Theory of General Relativity by Albert Einstein, in its final formulation, to the Royal Prussian Academy of Sciences. To celebrate 100 years of general relativity, World Scientific publishes this volume with a dual goal: to assess the current status of the field of general relativity in broad terms, and discuss future directions. The volume thus consists of broad overviews summarizing major developments over the past decades and their perspective contributions.
Directory of Open Access Journals (Sweden)
Siddiqui Saad
2011-04-01
Full Text Available Abstract Background There is a strong association between stillbirth and fetal growth restriction. Early detection and management of IUGR can lead to reduce related morbidity and mortality. In this paper we have reviewed effectiveness of fetal movement monitoring and Doppler velocimetry for the detection and surveillance of high risk pregnancies and the effect of this on prevention of stillbirths. We have also reviewed effect of maternal body mass index (BMI screening, symphysial-fundal height measurement and targeted ultrasound in detection and triage of IUGR in the community. Methods We systematically reviewed all published literature to identify studies related to our interventions. We searched PubMed, Cochrane Library, and all World Health Organization Regional Databases and included publications in any language. Quality of available evidence was assessed using GRADE criteria. Recommendations were made for the Lives Saved Tool (LiST based on rules developed by the Child Health Epidemiology Group. Given the paucity of evidence related to the effect of detection and management of IUGR on stillbirths, we undertook Delphi based evaluation from experts in the field. Results There was insufficient evidence to recommend against or in favor of routine use of fetal movement monitoring for fetal well being. (1 Detection and triage of IUGR with the help of (1a maternal BMI screening, (1b symphysial-fundal height measurement and (1c targeted ultrasound can be an effective method of reducing IUGR related perinatal morbidity and mortality. Pooled results from sixteen studies shows that Doppler velocimetry of umbilical and fetal arteries in ‘high risk’ pregnancies, coupled with the appropriate intervention, can reduce perinatal mortality by 29 % [RR 0.71, 95 % CI 0.52-0.98]. Pooled results for impact on stillbirth showed a reduction of 35 % [RR 0.65, 95 % CI 0.41-1.04]; however, the results did not reach the conventional limits of statistical
Subset selection from generalized logistic populations
Laan, van der M.J.; Laan, van der P.
1997-01-01
We give an introduction to the logistic and generalized logistic distributions. These generalized logistic distributions Type-I, Type-II and Type-III are indexed by a real valued parameter. They have been derived as mixtures with the standard logistic distribution and for discrete values of the
Aagestad, Cecilie; Tyssen, Reidar; Sterud, Tom
2016-03-08
Doctor -certified sick leave is prevalent in the health and social sector. We examined whether the higher risk of doctor-certified sick leave in women in health and social occupations compared to women in other occupations was explained by particular work-related psychosocial and mechanical risk factors. A randomly drawn cohort aged 18-69 years from the general population in Norway was surveyed in 2009 (n = 12,255, response at baseline = 60.9 %), and was followed up in the national registry of social transfer payments in 2010. Eligible respondents were women registered with an active employee relationship for ≥100 actual working days in 2009 and 2010 (n = 3032). Using this sample, we compared health and social workers (n = 661) with the general working population (n = 2371). The outcome of interest was long-term sick leave (LTSL) ≥21 working days during 2010. Eight psychosocial and eight mechanical factors were evaluated. After adjusting for age, previous LTSL, education and working hours/week, women in health and social occupations had a higher risk for LTSL compared with women in the general working population (OR = 1.42, 95 % CI = 1.13-1.79; p = 0.003). After adjusting for psychosocial and mechanical factors, 70 % of the excess risk for LTSL was explained compared with the initial model. The main contributory factors to the increased risk were threats of violence and violence, emotional demands and awkward lifting. Psychosocial and mechanical factors explained much of the excess risk for LTSL in women in health and social occupations compared with working women in general. Psychosocial risk factors were the most important contributors.
Directory of Open Access Journals (Sweden)
Cecilie Aagestad
2016-03-01
Full Text Available Abstract Background Doctor –certified sick leave is prevalent in the health and social sector. We examined whether the higher risk of doctor-certified sick leave in women in health and social occupations compared to women in other occupations was explained by particular work-related psychosocial and mechanical risk factors. Methods A randomly drawn cohort aged 18–69 years from the general population in Norway was surveyed in 2009 (n = 12,255, response at baseline = 60.9 %, and was followed up in the national registry of social transfer payments in 2010. Eligible respondents were women registered with an active employee relationship for ≥100 actual working days in 2009 and 2010 (n = 3032. Using this sample, we compared health and social workers (n = 661 with the general working population (n = 2371. The outcome of interest was long-term sick leave (LTSL ≥21 working days during 2010. Eight psychosocial and eight mechanical factors were evaluated. Results After adjusting for age, previous LTSL, education and working hours/week, women in health and social occupations had a higher risk for LTSL compared with women in the general working population (OR = 1.42, 95 % CI = 1.13–1.79; p = 0.003. After adjusting for psychosocial and mechanical factors, 70 % of the excess risk for LTSL was explained compared with the initial model. The main contributory factors to the increased risk were threats of violence and violence, emotional demands and awkward lifting. Conclusions Psychosocial and mechanical factors explained much of the excess risk for LTSL in women in health and social occupations compared with working women in general. Psychosocial risk factors were the most important contributors.
General Relativity in (1 + 1) Dimensions
Boozer, A. D.
2008-01-01
We describe a theory of gravity in (1 + 1) dimensions that can be thought of as a toy model of general relativity. The theory should be a useful pedagogical tool, because it is mathematically much simpler than general relativity but shares much of the same conceptual structure; in particular, it gives a simple illustration of how gravity arises…
A general consumer-resource population model
Lafferty, Kevin D.; DeLeo, Giulio; Briggs, Cheryl J.; Dobson, Andrew P.; Gross, Thilo; Kuris, Armand M.
2015-01-01
Food-web dynamics arise from predator-prey, parasite-host, and herbivore-plant interactions. Models for such interactions include up to three consumer activity states (questing, attacking, consuming) and up to four resource response states (susceptible, exposed, ingested, resistant). Articulating these states into a general model allows for dissecting, comparing, and deriving consumer-resource models. We specify this general model for 11 generic consumer strategies that group mathematically into predators, parasites, and micropredators and then derive conditions for consumer success, including a universal saturating functional response. We further show how to use this framework to create simple models with a common mathematical lineage and transparent assumptions. Underlying assumptions, missing elements, and composite parameters are revealed when classic consumer-resource models are derived from the general model.
Manganese Exposure in the General Population in a Mining District ...
International Development Research Centre (IDRC) Digital Library (Canada)
Manganese Exposure in the General Population in a Mining District (Mexico) ... in a population living close to a mine and mineral processing plant in Mexico ... Call for proposals: Innovations for the economic inclusion of marginalized youth.
Dynamics of relative motion of test particles in general relativity
International Nuclear Information System (INIS)
Bazanski, S.L.
1977-01-01
Several variational principles which lead to the first and the second geodesic deviation equations, recently formulated by the author and used for the description of the relative motion of test particles in general relativity are presented. Relations between these principles are investigated and exhibited. The Hamilton-Jacobi equation is also studied for these generalized deviations and the conservation laws appearing here are discussed
The Confrontation between General Relativity and Experiment
Directory of Open Access Journals (Sweden)
Will Clifford
2001-01-01
Full Text Available The status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed. Einstein's equivalence principle (EEP is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law will search for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected in an amount that agrees with general relativity to half a percent using the Hulse-Taylor binary pulsar, and new binary pulsar systems may yield further improvements.When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.
Particle field in bimetric general relativity
International Nuclear Information System (INIS)
Falik, D.; Rosen, N.
1980-01-01
The field equations of the bimetric general relativity theory proposed recently by one of the authors (N. Rosen) are put into a static form. The equations are solved near the Schwarzschild sphere, and it is found that the field differs from that of the Einstein general relativity theory: instead of a black hole, one has an impenetrable sphere. For larger distances the field is found to agree with that of ordinary general relativity, so that solar system observations cannot distinguish between the two theories. For very large distances one gets a cosmic contribution to the field which may affect the dynamics of clusters of galaxies
Compact objects in bimetric general relativity
International Nuclear Information System (INIS)
Harpaz, A.; Rosen, N.
1985-01-01
The field equations of the bimetric general relativity theory proposed by one of the authors (N. Rosen), in the static form, are solved in order to investigate the structure of a star. It is found that for an ordinary star the bimetric theory gives the same results as the Einstein general relativity theory. However, for a collapsed star the two theories give different results. In the bimetric theory a configuration in hydrostatic equilibrium exists for a collapsed star filling its Schwarzschild sphere. In general relativity no equilibrium configuration exists in this region, and the star shrinks to a point singularity to form a black hole
O(3)-invariant tunneling in general relativity
International Nuclear Information System (INIS)
Berezin, V.A.; Tkachev, I.I.; Kuzmin, V.A.; AN SSSR, Moscow. Inst. Yadernykh Issledovanij)
1987-12-01
We derived a general formula for the action for any O(3)-invariant tunneling processes in false vacuum decay in general relativity. The general classification of the bubble Euclidean trajectories is elaborated and explicit expressions for bounces for some processes like the vacuum creation of a double bubble, in particular in the vicinity of a black hole; the subbarrier creation of the Einstein-Rosen bridge, creation from nothing of two Minkowski worlds connected by a shell etc., are given. (orig.)
Axisymmetric solution with charge in general relativity
International Nuclear Information System (INIS)
Arutyunyan, G.G.; Papoyan, V.V.
1989-01-01
The possibility of generating solutions to the equations of general relativity from known solutions of the generalized theory of gravitation and vice versa is proved. An electrovac solution to Einstein's equations that describes a static axisymmetric gravitational field is found. 14 refs
Characteristics of the General Physics student population.
Hunt, Gary L.
2006-12-01
Are pre-medical students different than the other students in a General physics class? They often appear to be different, based on how often they seek help from the instructor or how nervous they are about 2 points on a lab report. But are these students different in a measurable characteristic? The purpose of this study is to better understand the characteristics of the students in the introductory physics classes. This is the first step toward improving the instruction. By better understanding the students the classroom, the organization and pedagogy can be adjusted to optimize student learning. The characteristics to be investigated during this study are: · student epistemological structure, · student attitudes, · science course preparation prior to this course, · study techniques used, · physics concepts gained during the class · performance in the class. The data will be analyzed to investigate differences between groups. The groups investigated will be major, gender, and traditional/nontraditional students.
Tabler, Jennifer; Utz, Rebecca L; Smith, Ken R; Hanson, Heidi A; Geist, Claudia
2018-02-01
This study seeks to examine the long-term reproductive consequences of eating disorders (ED), to assess variation in reproductive outcomes by ED type, and to examine reproductive differences between women with previous ED diagnosis and their discordant sisters. Using a sample of women with previous ED diagnosis generated by the Utah Population Database, this study compares the fecundity (parity) and age at first birth of women by ED subtype (bulimia nervosa [BN], anorexia nervosa [AN], and ED not otherwise specified [EDNOS]) (n = 1,579). We also employed general population match case-control, and discordant sibling pair analyses, to estimate the magnitude of association between EDs and reproductive outcomes. Women previously diagnosed with AN or EDNOS experienced delayed first birth (HRR = 0.33, HRR = 0.34, respectively) and lower parity (IRR = 0.19, IRR = 0.22, respectively) relative to BN (p < .05), the general population (p < .05), and closest-aged sisters (p < .05). Women previously diagnosed with BN experienced more moderate reductions and delays to their reproduction, and had similar reproductive outcomes as their discordant sisters. Clinicians should consider ED type and family fertility histories when addressing the long-term reproductive health needs of women with prior AN, BN, or EDNOS diagnosis. Women previously diagnosed with AN or EDNOS likely experience the greatest reductions and delays in reproduction across their lifespan. Reproductive health screenings may be especially critical for the wellbeing of women with a history of AN or EDNOS. © 2018 Wiley Periodicals, Inc.
Einstein and General Relativity: Historical Perspectives.
Chandrasekhar, S.
1979-01-01
This paper presented in the 1978 Oppenheimer Memorial Lecture at Los Alamos Scientific Laboratories on August 17, 1978, discusses Einstein's contributions to physics, in particular, his discovery of the general theory of relativity. (HM)
Quantum theory and Einstein's general relativity
International Nuclear Information System (INIS)
Borzeszkowski, H.H.v.; Treder, H.J.
1984-01-01
The paper concerns Einstein's general relativity, wave mechanics and the quantization of Einstein's gravitation equations. The principle of equivalence and its association with both wave mechanics and quantum gravity, is discussed. (U.K.)
Black hole dynamics in general relativity
Indian Academy of Sciences (India)
Abstract. Basic features of dynamical black holes in full, non-linear general relativity are summarized in a pedagogical fashion. Qualitative properties of the evolution of various horizons follow directly from the celebrated Raychaudhuri equation.
Einstein and general relativity: historical perspectives
International Nuclear Information System (INIS)
Chandrasekhar, S.
1978-01-01
The place of Einstein in 20th-century physics is discussed. The basic ideas that led Einstein to his theory of gravitation by the sheer power of speculative thought are described in the most general terms. The prediction of the bending of starlight by the Sun and the eclipse expedition of 1919 are recounted. The author feels that ''the general theory of relativity is incredibly rich in its content;...one finds a glittering face at almost every turn.'' The prediction of black holes by general relativity is noted
Personality disorders and smoking in Spanish general and clinical population
Fernández del Río, Elena; López Durán, Ana; Martinez, Ursula; Becoña, Elisardo
2016-01-01
Background: There is consistent evidence about the relationship between smoking and mental health. This study compares the relationship between tobacco use and personality disorders (PDs) in Spanish adults from general and clinical population, taking into account nicotine dependence (ND), and the presence of any mental disorder. Method: The sample was made up of 1,079 smokers (519 from general population, 560 from clinical population). PDs were assessed by means of the Inter...
Energy and Uncertainty in General Relativity
Cooperstock, F. I.; Dupre, M. J.
2018-03-01
The issue of energy and its potential localizability in general relativity has challenged physicists for more than a century. Many non-invariant measures were proposed over the years but an invariant measure was never found. We discovered the invariant localized energy measure by expanding the domain of investigation from space to spacetime. We note from relativity that the finiteness of the velocity of propagation of interactions necessarily induces indefiniteness in measurements. This is because the elements of actual physical systems being measured as well as their detectors are characterized by entire four-velocity fields, which necessarily leads to information from a measured system being processed by the detector in a spread of time. General relativity adds additional indefiniteness because of the variation in proper time between elements. The uncertainty is encapsulated in a generalized uncertainty principle, in parallel with that of Heisenberg, which incorporates the localized contribution of gravity to energy. This naturally leads to a generalized uncertainty principle for momentum as well. These generalized forms and the gravitational contribution to localized energy would be expected to be of particular importance in the regimes of ultra-strong gravitational fields. We contrast our invariant spacetime energy measure with the standard 3-space energy measure which is familiar from special relativity, appreciating why general relativity demands a measure in spacetime as opposed to 3-space. We illustrate the misconceptions by certain authors of our approach.
Supersymmetry, General Relativity and Unity of Nature
Shima, Kazunari; Tsuda, Motomu
2008-01-01
The basic idea and some physical implications of nonlinear supersymmetric general relativity (NLSUSY GR) are presented. NLSUSY GR may give new insights into the origin of mass and the mysterious relations between the cosmology and the low energy particle physics, e.g. the spontaneous SUSY breaking scale, the cosmological constant, the (dark) energy density of the universe and the neutrino mass.
Teaching General Relativity to the Layperson
Egdall, Mark
2009-01-01
This paper describes a lay course on general relativity (GR) given at the Osher Lifelong Learning Institute at Florida International University. It is presented in six hour-and-a-half weekly sessions. Other courses offered by the author include special relativity (which precedes the course described here), quantum theory, and cosmology. Students…
Black hole based tests of general relativity
International Nuclear Information System (INIS)
Yagi, Kent; Stein, Leo C
2016-01-01
General relativity has passed all solar system experiments and neutron star based tests, such as binary pulsar observations, with flying colors. A more exotic arena for testing general relativity is in systems that contain one or more black holes. Black holes are the most compact objects in the Universe, providing probes of the strongest-possible gravitational fields. We are motivated to study strong-field gravity since many theories give large deviations from general relativity only at large field strengths, while recovering the weak-field behavior. In this article, we review how one can probe general relativity and various alternative theories of gravity by using electromagnetic waves from a black hole with an accretion disk, and gravitational waves from black hole binaries. We first review model-independent ways of testing gravity with electromagnetic/gravitational waves from a black hole system. We then focus on selected examples of theories that extend general relativity in rather simple ways. Some important characteristics of general relativity include (but are not limited to) (i) only tensor gravitational degrees of freedom, (ii) the graviton is massless, (iii) no quadratic or higher curvatures in the action, and (iv) the theory is four-dimensional. Altering a characteristic leads to a different extension of general relativity: (i) scalar–tensor theories, (ii) massive gravity theories, (iii) quadratic gravity, and (iv) theories with large extra dimensions. Within each theory, we describe black hole solutions, their properties, and current and projected constraints on each theory using black hole based tests of gravity. We close this review by listing some of the open problems in model-independent tests and within each specific theory. (paper)
General very special relativity in Finsler cosmology
International Nuclear Information System (INIS)
Kouretsis, A. P.; Stathakopoulos, M.; Stavrinos, P. C.
2009-01-01
General very special relativity (GVSR) is the curved space-time of very special relativity (VSR) proposed by Cohen and Glashow. The geometry of general very special relativity possesses a line element of Finsler geometry introduced by Bogoslovsky. We calculate the Einstein field equations and derive a modified Friedmann-Robertson-Walker cosmology for an osculating Riemannian space. The Friedmann equation of motion leads to an explanation of the cosmological acceleration in terms of an alternative non-Lorentz invariant theory. A first order approach for a primordial-spurionic vector field introduced into the metric gives back an estimation of the energy evolution and inflation.
The Confrontation between General Relativity and Experiment.
Will, Clifford M
2014-01-01
The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.
On generalization uniaxial stress-strain relation
International Nuclear Information System (INIS)
Sahay, C.; Dubey, R.N.
1980-01-01
Different forms of constitutive relations have been advanced for elastic, plastic and elastic-plastic behaviour of materials. It is shown that the various forms of the stress-strain relationship are specialized forms of generalization of a single stress-strain relation. For example, it is shown how the laws of elastic deformation, and the incremental and total deformation relationship for plastic behaviour are derivable from the Ramberg-Osgood relation. (orig.)
Generalized transformations and coordinates for static spherically symmetric general relativity
Hill, James M.; O'Leary, Joseph
2018-04-01
We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington-Finkelstein transformation and the Kruskal-Szekeres coordinates.
Generalized transformations and coordinates for static spherically symmetric general relativity.
Hill, James M; O'Leary, Joseph
2018-04-01
We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington-Finkelstein transformation and the Kruskal-Szekeres coordinates.
Generalized Disjunctions in (Infinitary) Structural Consequence Relations
Czech Academy of Sciences Publication Activity Database
Cintula, Petr; Noguera, C.
2012-01-01
Roč. 18, č. 3 (2012), s. 442-443 ISSN 1079-8986. [Logic Colloquium 2011. 11.07.2011-16.07.2011, Barcelona] R&D Projects: GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10300504 Keywords : Abstract Algebraic Logic * Generalized disjunction * Proof by cases properties * Consequence relations Subject RIV: BA - General Mathematics http://www.math.ucla.edu/~asl/bsl/1803- toc .htm
Hatzenbuehler, Mark L; Keyes, Katherine M; Narrow, William E; Grant, Bridget F; Hasin, Deborah S
2008-07-01
This study sought to determine whether black/white disparities in service utilization for mental health and substance use disorders persist or are diminished among individuals with psychiatric comorbidity in the general population. The 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions was used to identify individuals with lifetime co-occurring substance use disorders and mood/anxiety disorders (N = 4250; whites, N = 3597; blacks, N = 653). Lifetime service utilization for problems with mood, anxiety, alcohol, and drugs was assessed. Compared to whites, blacks with co-occurring mood or anxiety and substance use disorders were significantly less likely to receive services for mood or anxiety disorders, equally likely to receive services for alcohol use disorders, and more likely to receive some types of services for drug use disorders. Regardless of race/ethnicity, individuals with these co-occurring disorders were almost twice as likely to use services for mood/anxiety disorders than for substance use disorders. Despite the fact that comorbidity generally increases the likelihood of service use, black/white disparities in service utilization among an all-comorbid sample were found, although these disparities differed by type of disorder. Further research is warranted to understand the factors underlying these differences. Prevention and intervention strategies are needed to address the specific mental health needs of blacks with co-occurring disorders, as well as the overall lack of service use for substance use disorders among individuals with co-occurring psychiatric conditions.
Einstein and the history of general relativity
International Nuclear Information System (INIS)
Howard, D.; Stachel, J.
1989-01-01
This book is a collection of essays by the authors and other people that deal with scientific opinions that led Einstein and his contemporaries to their views of general relativity. Some of the essays explore Einstein's passage from the special theory through a sequence of gravitational theories to the discovery of the field equations of the grand theory in November 1915. Two other essays discuss Einstein's public and private exchanges with Max Abraham and Tullio Levi-Civita in 1913 and 1914. A sympathetic picture of H.A. Lorentz's reaction to the general theory of relativity is included, and a careful and insightful essay on the early understanding of the Schwarzschild-Droste solution to the field equations of general relativity is presented. One paper presents a discussion on the state of the enterprise of general relativity between 1925 and 1928, and a short essay details the history of steps toward quantum gravitational through canonical quantization. A discussion of the history of derivations of the geodesic equation of motion from the field equation and conservation laws of the general theory is presented. The early history of geometrical unified field theories is included
Generalized Landau-Pollak uncertainty relation
International Nuclear Information System (INIS)
Miyadera, Takayuki; Imai, Hideki
2007-01-01
The Landau-Pollak uncertainty relation treats a pair of rank one projection valued measures and imposes a restriction on their probability distributions. It gives a nontrivial bound for summation of their maximum values. We give a generalization of this bound (weak version of the Landau-Pollak uncertainty relation). Our generalization covers a pair of positive operator valued measures. A nontrivial but slightly weak inequality that can treat an arbitrary number of positive operator valued measures is also presented. A possible application to the problem of separability criterion is also suggested
The Confrontation between General Relativity and Experiment
Directory of Open Access Journals (Sweden)
Will Clifford M.
2006-03-01
Full Text Available The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed. Einstein’s equivalence principle (EEP is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and other binary pulsar systems have yielded other tests, especially of strong-field effects. When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.
Relational Coordination in Danish General Practice
DEFF Research Database (Denmark)
Lundstrøm, Sanne Lykke
. The dissertation present the research study and a collection of three research papers prepared during the period from May 2010 to June 2014. Relational coordination and organisational social capital are measures of novel aspects of an organisation's performance. Relational coordination analyse the communication...... and relationship networks through which work is coordinated across functional and organisational boundaries. Previous studies have shown that relational coordination is positively associated with delivery of care for patients with chronic illness. Organisational social capital is used when analysing...... the psychosocial work environment in organisations, and is seen as a powerful resources for improving organisational performance. Relational coordination and organisational social capital may oer new insight and opportunities for general practice to learn. General practice provides cost-efficient, first...
Nonfasting triglycerides, cholesterol, and ischemic stroke in the general population
DEFF Research Database (Denmark)
Varbo, Anette; Nordestgaard, Børge G; Tybjaerg-Hansen, Anne
2011-01-01
Current guidelines on stroke prevention have recommendations on desirable cholesterol levels, but not on nonfasting triglycerides. We compared stepwise increasing levels of nonfasting triglycerides and cholesterol for their association with risk of ischemic stroke in the general population....
Generating perfect fluid spheres in general relativity
Boonserm, Petarpa; Visser, Matt; Weinfurtner, Silke
2005-06-01
Ever since Karl Schwarzschild’s 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star—a static spherically symmetric blob of fluid with position-independent density—the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the last 90 years a tangle of specific perfect fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map perfect fluid spheres into perfect fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known perfect fluid spheres, sometimes lead to new previously unknown perfect fluid spheres, and in general can be used to develop a systematic way of classifying the set of all perfect fluid spheres.
Generating perfect fluid spheres in general relativity
International Nuclear Information System (INIS)
Boonserm, Petarpa; Visser, Matt; Weinfurtner, Silke
2005-01-01
Ever since Karl Schwarzschild's 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star--a static spherically symmetric blob of fluid with position-independent density--the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the last 90 years a tangle of specific perfect fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map perfect fluid spheres into perfect fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known perfect fluid spheres, sometimes lead to new previously unknown perfect fluid spheres, and in general can be used to develop a systematic way of classifying the set of all perfect fluid spheres
Generalization of Gibbs Entropy and Thermodynamic Relation
Park, Jun Chul
2010-01-01
In this paper, we extend Gibbs's approach of quasi-equilibrium thermodynamic processes, and calculate the microscopic expression of entropy for general non-equilibrium thermodynamic processes. Also, we analyze the formal structure of thermodynamic relation in non-equilibrium thermodynamic processes.
Gravity: An Introduction to Einstein's General Relativity
International Nuclear Information System (INIS)
Fabris, Julio C
2004-01-01
General relativity is one of the cornerstones of modern physics. In spite of this, the teaching of general relativity at undergraduate level remains quite marginal. The reasons for this particular situation are quite well known. We can quote, for example, two of them: general relativity requires specific mathematical tools that are somehow outside the mainstream of undergraduate technical development; moreover, this is a branch of physics whose observational and experimental applications have remained rare until recent times, and even though this scenario has changed dramatically in the last few years, the new situation has not yet been absorbed into undergraduate teaching. In this new book, Hartle attempts to address the difficulties that must be faced by anyone who teaches general relativity at undergraduate level. In order to not scare the student with the hard technical preparation needed to obtain the basic equations of general relativity, Einstein's equations, he simply gives up the idea of introducing these equations at the very beginning. Instead, he chooses to present Einstein's equations, with most of the mathematics needed to do them, in the last part of the book. This delicate (and of course dangerous) choice has the advantage of introducing the reader first to the physical aspects of general relativity. This approach can be dangerous because the relevant solutions of the equations necessary to discuss the physical content of general relativity are presented first without a formal derivation. The book is divided into three parts. In the first, covering five chapters of the 24 in the whole book, Newtonian physics and special relativity are reviewed. This review is done in a manner that prepares the reader for the subsequent discussion of general relativity itself. The principle of relativity, the variational principle, the geometrical content of Newtonian theory and the main ideas behind special relativity are all presented. The heart of the book is, in
Summary of classical general relativity workshop
Indian Academy of Sciences (India)
In the classical general relativity workshop, ten lectures were presented on various topics. The topics included aspects of black-hole physics, gravitational collapse and the formation of black holes, specific stellar models like a superdense star, method of extracting solutions by exploiting Noether symmetry, brane world and.
The confrontation between general relativity and experiment
Indian Academy of Sciences (India)
... and tests of gravity at short distance to look for extra spatial dimensions could further constrain alternatives to general relativity. Laser Interferometric Gravitational Wave Observatories on Earth and in space may provide new tests of scalar–tensor gravity and graviton-mass theories via the properties of gravitational waves.
Tests of General Relativity with GW150914
Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gatto, A.; Gaur, G.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Holz, D. E.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Islas, G.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Johnson-McDaniel, N. K.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, M. K.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, C.; Kim, J.; Kim, K.; Kim, Nam-Gyu; Kim, Namjun; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Kokeyama, K.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B. M.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Logue, J.; Lombardi, A. L.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lück, H.; Lundgren, A. P.; Luo, J.; Lynch, R.; Ma, Y.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R. M.; Mageswaran, M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mendoza-Gandara, D.; Mercer, R. A.; Merilh, E.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nedkova, K.; Nelemans, G.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pan, Y.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Riles, K.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Setyawati, Y.; Sevigny, A.; Shaddock, D. A.; Shah, S.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; White, D. J.; Whiting, B. F.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Wright, J. L.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, F.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; Boyle, M.; Campanelli, M.; Hemberger, D. A.; Kidder, L. E.; Ossokine, S.; Scheel, M. A.; Szilagyi, B.; Teukolsky, S.; Zlochower, Y.; LIGO Scientific; Virgo Collaborations
2016-06-01
The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 1013 km . In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.
Tests of General Relativity with GW150914.
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Rolland, L; Rollins, J G; Roma, V J; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Schönbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Setyawati, Y; Sevigny, A; Shaddock, D A; Shah, S; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sutton, P J; Swinkels, B L; Szczepańczyk, M J; Tacca, M; Talukder, D; Tanner, D B; Tápai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; Töyrä, D; Travasso, F; Traylor, G; Trifirò, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; van Bakel, N; van Beuzekom, M; van den Brand, J F J; Van Den Broeck, C; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vinciguerra, S; Vine, D J; Vinet, J-Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L-W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Weßels, P; Westphal, T; Wette, K; Whelan, J T; White, D J; Whiting, B F; Williams, D; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Wright, J L; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yap, M J; Yu, H; Yvert, M; Zadrożny, A; Zangrando, L; Zanolin, M; Zendri, J-P; Zevin, M; Zhang, F; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J; Boyle, M; Campanelli, M; Hemberger, D A; Kidder, L E; Ossokine, S; Scheel, M A; Szilagyi, B; Teukolsky, S; Zlochower, Y
2016-06-03
The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13} km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.
General relativity and gravitation a centennial perspective
Berger, Beverly K; Isenberg, James; MacCallum, Malcolm
2015-01-01
Explore spectacular advances in cosmology, relativistic astrophysics, gravitational wave science, mathematics, computational science, and the interface of gravitation and quantum physics with this unique celebration of the centennial of Einstein's discovery of general relativity. Twelve comprehensive and in-depth reviews, written by a team of world-leading international experts, together present an up-to-date overview of key topics at the frontiers of these areas, with particular emphasis on the significant developments of the last three decades. Interconnections with other fields of research are also highlighted, making this an invaluable resource for both new and experienced researchers. Commissioned by the International Society on General Relativity and Gravitation, and including accessible introductions to cutting-edge topics, ample references to original research papers, and informative colour figures, this is a definitive reference for researchers and graduate students in cosmology, relativity, and grav...
General Relativity and John Archibald Wheeler
Ciufolini, Ignazio
2010-01-01
Observational and experimental data pertaining to gravity and cosmology are changing our view of the Universe. General relativity is a fundamental key for the understanding of these observations and its theory is undergoing a continuing enhancement of its intersection with observational and experimental data. These data include direct observations and experiments carried out in our solar system, among which there are direct gravitational wave astronomy, frame dragging and tests of gravitational theories from solar system and spacecraft observations. This book explores John Archibald Wheeler's seminal and enduring contributions in relativistic astrophysics and includes: the General Theory of Relativity and Wheeler's influence; recent developments in the confrontation of relativity with experiments; the theory describing gravitational radiation, and its detection in Earth-based and space-based interferometer detectors as well as in Earth-based bar detectors; the mathematical description of the initial value pro...
Development of Einstein's general theory of relativity
International Nuclear Information System (INIS)
Datta, B.K.
1980-01-01
Starting from Poincare's Lorentz-invariant theory of gravity formulated in 1906, development of Einstein's general theory of relativity during 1906-1916 is discussed. Three stages in this development are recognised. In the first stage during 1907-1914, Einstein tried to extend the relativity principle of uniform motion to the frames in non-uniform motion. For this purpose, he introduced the principle of equivalence which made it possible to calculate the effect of homogeneous gravitational field on arbitrary physical processes. During the second stage comprising years 1912-1914 overlapping the first stage, Einstein and Grossmann were struggling to translate physical postulates into the language of the absolute differential calculus. In the period 1915-1916, Einstein formulated the field equations of general relativity. While discussing these developmental stages, theories of gravitation formulated by Abraham, Nordstroem and Mie are also discussed. (M.G.B.)
Partial Differential Equations in General Relativity
International Nuclear Information System (INIS)
Choquet-Bruhat, Yvonne
2008-01-01
General relativity is a physical theory basic in the modeling of the universe at the large and small scales. Its mathematical formulation, the Einstein partial differential equations, are geometrically simple, but intricate for the analyst, involving both hyperbolic and elliptic PDE, with local and global problems. Many problems remain open though remarkable progress has been made recently towards their solutions. Alan Rendall's book states, in a down-to-earth form, fundamental results used to solve different types of equations. In each case he gives applications to special models as well as to general properties of Einsteinian spacetimes. A chapter on ODE contains, in particular, a detailed discussion of Bianchi spacetimes. A chapter entitled 'Elliptic systems' treats the Einstein constraints. A chapter entitled 'Hyperbolic systems' is followed by a chapter on the Cauchy problem and a chapter 'Global results' which contains recently proved theorems. A chapter is dedicated to the Einstein-Vlasov system, of which the author is a specialist. On the whole, the book surveys, in a concise though precise way, many essential results of recent interest in mathematical general relativity, and it is very clearly written. Each chapter is followed by an up to date bibliography. In conclusion, this book will be a valuable asset to relativists who wish to learn clearly-stated mathematical results and to mathematicians who want to penetrate into the subtleties of general relativity, as a mathematical and physical theory. (book review)
Partial Differential Equations in General Relativity
Energy Technology Data Exchange (ETDEWEB)
Choquet-Bruhat, Yvonne
2008-09-07
General relativity is a physical theory basic in the modeling of the universe at the large and small scales. Its mathematical formulation, the Einstein partial differential equations, are geometrically simple, but intricate for the analyst, involving both hyperbolic and elliptic PDE, with local and global problems. Many problems remain open though remarkable progress has been made recently towards their solutions. Alan Rendall's book states, in a down-to-earth form, fundamental results used to solve different types of equations. In each case he gives applications to special models as well as to general properties of Einsteinian spacetimes. A chapter on ODE contains, in particular, a detailed discussion of Bianchi spacetimes. A chapter entitled 'Elliptic systems' treats the Einstein constraints. A chapter entitled 'Hyperbolic systems' is followed by a chapter on the Cauchy problem and a chapter 'Global results' which contains recently proved theorems. A chapter is dedicated to the Einstein-Vlasov system, of which the author is a specialist. On the whole, the book surveys, in a concise though precise way, many essential results of recent interest in mathematical general relativity, and it is very clearly written. Each chapter is followed by an up to date bibliography. In conclusion, this book will be a valuable asset to relativists who wish to learn clearly-stated mathematical results and to mathematicians who want to penetrate into the subtleties of general relativity, as a mathematical and physical theory. (book review)
The Confrontation between General Relativity and Experiment
Directory of Open Access Journals (Sweden)
Clifford M. Will
2014-06-01
Full Text Available The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein’s equivalence principle (EEP is well supported by experiments such as the Eötvös experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse–Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.
Coffey, Sean; Bano, Gul; Mason, Helen D
2006-02-01
We examined whether women with polycystic ovary syndrome (PCOS) have poorer health-related quality of life (HRQoL) than women in the general population and than patients with other medical conditions. Women with PCOS were recruited from an outpatient clinic and a control group was recruited from a family planning clinic. Both groups completed the Short Form-36 (SF-36) and the Polycystic Ovary Syndrome Questionnaire (PCOSQ). SF-36 data from the Oxford Health and Lifestyle Survey were used to compare PCOS with other conditions. Twenty-two women with PCOS and 96 control women took part. Women with PCOS scored lower in both summary scores of the SF-36 and in all domains of the PCOSQ. After adjusting for body mass index, the differences between the groups in the SF-36 disappeared, while those in the PCOSQ remained. When compared with asthma, epilepsy, diabetes, back pain, arthritis and coronary heart disease, our PCOS group had the same or better physical HRQoL but poorer psychological HRQoL. The PCOSQ showed good internal reliability, good concurrent validity and good discriminant validity. PCOS has a negative impact on HRQoL even when compared with other serious health conditions. The PCOSQ is reliable and valid for clinical use.
Attitudes of General Population and Physicians Towards Alcohol Addiction
Directory of Open Access Journals (Sweden)
Hasan Mayda
2015-11-01
Full Text Available Aim: To assess attitudes of general population and medical doctors towards alcohol addiction. Material and Method: 99 medical doctors who worked university hospitals, public hospitals or health centers and 101 people who selected from the community to represent the overall population enrolled in our study. All the participants were asked to anonymously complete a questinnaire about stigmatization, including questions assessing social distance, dangerousness and skillfullness. Results: Contrary to expectattions, there were not statistically significant differences in the attitudes of general poupulation and physicians towards alcohol dependences (all scales, p>0.05.Discussion: Both medical doctors and general population appear to have negative thoughts about alcohol dependence. New education strategies is developed in the field of general medical education and psychiatry in order to change negative attitudes towards alkohol addiction.
General relativity with applications to astrophysics
Straumann, Norbert
2004-01-01
This text provides a comprehensive and timely introduction to general relativity The foundations of the theory in Part I are thoroughly developed together with the required mathematical background from differential geometry in Part III The six chapters in Part II are devoted to tests of general relativity and to many of its applications Binary pulsars are studied in considerable detail Much space is devoted to the study of compact objects, especially to black holes This includes a detailed derivation of the Kerr solution, Israel's proof of his uniqueness theorem, and derivations of the basic laws of black hole physics The final chapter of this part contains Witten's proof of the positive energy theorem The book addresses undergraduate and graduate students in physics, astrophysics and mathematics It is very well structured and should become a standard text for a modern treatment of gravitational physics The clear presentation of differential geometry makes it also useful for string theory and other fields of ...
A precise extragalactic test of General Relativity.
Collett, Thomas E; Oldham, Lindsay J; Smith, Russell J; Auger, Matthew W; Westfall, Kyle B; Bacon, David; Nichol, Robert C; Masters, Karen L; Koyama, Kazuya; van den Bosch, Remco
2018-06-22
Einstein's theory of gravity, General Relativity, has been precisely tested on Solar System scales, but the long-range nature of gravity is still poorly constrained. The nearby strong gravitational lens ESO 325-G004 provides a laboratory to probe the weak-field regime of gravity and measure the spatial curvature generated per unit mass, γ. By reconstructing the observed light profile of the lensed arcs and the observed spatially resolved stellar kinematics with a single self-consistent model, we conclude that γ = 0.97 ± 0.09 at 68% confidence. Our result is consistent with the prediction of 1 from General Relativity and provides a strong extragalactic constraint on the weak-field metric of gravity. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
Generalized Weierstrass Relations and Frobenius Reciprocity
International Nuclear Information System (INIS)
Matsutani, Shigeki
2006-01-01
This article investigates local properties of the further generalized Weierstrass relations for a spin manifold S immersed in a higher dimensional spin manifold M from the viewpoint of the study of submanifold quantum mechanics. We show that the kernel of a certain Dirac operator defined over S, which we call a submanifold Dirac operator, gives the data of the immersion. In the derivation, the simple Frobenius reciprocity of Clifford algebras S and M plays an important role
Screening vector field modifications of general relativity
International Nuclear Information System (INIS)
Beltrán Jiménez, Jose; Delvas Fróes, André Luís; Mota, David F.
2013-01-01
A screening mechanism for conformal vector–tensor modifications of general relativity is proposed. The conformal factor depends on the norm of the vector field and makes the field to vanish in high dense regions, whereas drives it to a non-null value in low density environments. Such process occurs due to a spontaneous symmetry breaking mechanism and gives rise to both the screening of fifth forces as well as Lorentz violations. The cosmology and local constraints are also computed
Interacting electromagnetic waves in general relativity
International Nuclear Information System (INIS)
Griffiths, J.B.
1976-01-01
The problem is considered of finding exact solutions of the Einstein-Maxwell equations which describe the physical situation of two colliding and subsequently interacting electromagnetic waves. The general theory of relativity predicts a nonlinear interaction between electromagnetic waves. The situation is described using an approximate geometrical method, and a new exact solution describing two interacting electromagnetic waves is given. This describes waves emitted from two sources mutually focusing each other on the opposite source. (author)
Gravity, general relativity theory and alternative theories
International Nuclear Information System (INIS)
Zel'dovich, Ya.B.; Grishchuk, L.P.; Moskovskij Gosudarstvennyj Univ.
1986-01-01
The main steps in plotting the current gravitation theory and some prospects of its subsequent development are reviewed. The attention is concentrated on a comparison of the relativistic gravitational field with other physical fields. Two equivalent formulations of the general relativity (GR) - geometrical and field-theoretical - are considered in detail. It is shown that some theories of gravity constructed as the field theories at a flat background space-time are in fact just different formulations of GR and not alternative theories
Between general relativity and quantum theory
International Nuclear Information System (INIS)
Rayski, J.
1982-01-01
Some possibilities of reconciling general relativity with quantum theory are discussed. The procedure of quantization is certainly not unique, but depends upon the choice of the coordinate conditions. Most versions of quantization predict the existence of gravitons, but it is also possible to formulate a quantum theory with a classical gravity whereby the expectation values of Tsub(μν) constitute the sources of the classical metric field. (author)
Testing General Relativity with Pulsar Timing
Directory of Open Access Journals (Sweden)
Stairs Ingrid H.
2003-01-01
Full Text Available Pulsars of very different types, including isolated objects and binaries (with short- and long-period orbits, and white-dwarf and neutron-star companions provide the means to test both the predictions of general relativity and the viability of alternate theories of gravity. This article presents an overview of pulsars, then discusses the current status of and future prospects for tests of equivalence-principle violations and strong-field gravitational experiments.
Probing the Higgs vacuum with general relativity
Mannheim, Philip D.; Kazanas, Demosthenes
1991-01-01
It is shown that the structure of the Higgs vacuum can be revealed in gravitational experiments which probe the Schwarzschild geometry to only one order in MG/r beyond that needed for the classical tests of general relativity. The possibility that deviations from the conventional geometry are at least theoretically conceivable is explored. The deviations obtained provide a diagnostic test for searching for the existence of macroscopic scalar fields and open up the possiblity for further exploring the Higgs mechanism.
Special relativity, electrodynamics, and general relativity from Newton to Einstein
Kogut, John B
2018-01-01
Special Relativity, Electrodynamics and General Relativity: From Newton to Einstein, Second Edition, is intended to teach (astro)physics, astronomy, and cosmology students how to think about special and general relativity in a fundamental, but accessible, way. Designed to render any reader a "master of relativity," everything on the subject is comprehensible and derivable from first principles. The book emphasizes problem solving, contains abundant problem sets, and is conveniently organized to meet the needs of both student and instructor. Fully revised, updated and expanded second edition Includes new chapters on magnetism as a consequence of relativity and electromagnetism Contains many improved and more engaging figures Uses less algebra resulting in more efficient derivations Enlarged discussion of dynamics and the relativistic version of Newton's second law
Quantum theory and Einstein's general relativity
International Nuclear Information System (INIS)
Borzeszkowski, H. von; Treder, H.
1982-01-01
We dicusss the meaning and prove the accordance of general relativity, wave mechanics, and the quantization of Einstein's gravitation equations themselves. Firstly, we have the problem of the influence of gravitational fields on the de Broglie waves, which influence is in accordance with Einstein's weak principle of equivalence and the limitation of measurements given by Heisenberg's uncertainty relations. Secondly, the quantization of the gravitational fields is a ''quantization of geometry.'' However, classical and quantum gravitation have the same physical meaning according to limitations of measurements given by Einstein's strong principle of equivalence and the Heisenberg uncertainties for the mechanics of test bodies
Relativity the special and the general theory
Einstein, Albert
2015-01-01
After completing the final version of his general theory of relativity in November 1915, Albert Einstein wrote a book about relativity for a popular audience. His intention was "to give an exact insight into the theory of relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics." The book remains one of the most lucid explanations of the special and general theories ever written. In the early 1920s alone, it was translated into ten languages, and fifteen editions in the original German appeared over the course of Einstein's lifetime. This new edition of Einstein's celebrated book features an authoritative English translation of the text along with an introduction and a reading companion by Hanoch Gutfreund and Jürgen Renn that examines the evolution of Einstein's thinking and casts his ideas in a broader present-day context. A special chapter explores the history...
Simple recursion relations for general field theories
International Nuclear Information System (INIS)
Cheung, Clifford; Shen, Chia-Hsien; Trnka, Jaroslav
2015-01-01
On-shell methods offer an alternative definition of quantum field theory at tree-level, replacing Feynman diagrams with recursion relations and interaction vertices with a handful of seed scattering amplitudes. In this paper we determine the simplest recursion relations needed to construct a general four-dimensional quantum field theory of massless particles. For this purpose we define a covering space of recursion relations which naturally generalizes all existing constructions, including those of BCFW and Risager. The validity of each recursion relation hinges on the large momentum behavior of an n-point scattering amplitude under an m-line momentum shift, which we determine solely from dimensional analysis, Lorentz invariance, and locality. We show that all amplitudes in a renormalizable theory are 5-line constructible. Amplitudes are 3-line constructible if an external particle carries spin or if the scalars in the theory carry equal charge under a global or gauge symmetry. Remarkably, this implies the 3-line constructibility of all gauge theories with fermions and complex scalars in arbitrary representations, all supersymmetric theories, and the standard model. Moreover, all amplitudes in non-renormalizable theories without derivative interactions are constructible; with derivative interactions, a subset of amplitudes is constructible. We illustrate our results with examples from both renormalizable and non-renormalizable theories. Our study demonstrates both the power and limitations of recursion relations as a self-contained formulation of quantum field theory.
A general modeling framework for describing spatially structured population dynamics
Sample, Christine; Fryxell, John; Bieri, Joanna; Federico, Paula; Earl, Julia; Wiederholt, Ruscena; Mattsson, Brady; Flockhart, Tyler; Nicol, Sam; Diffendorfer, James E.; Thogmartin, Wayne E.; Erickson, Richard A.; Norris, D. Ryan
2017-01-01
Variation in movement across time and space fundamentally shapes the abundance and distribution of populations. Although a variety of approaches model structured population dynamics, they are limited to specific types of spatially structured populations and lack a unifying framework. Here, we propose a unified network-based framework sufficiently novel in its flexibility to capture a wide variety of spatiotemporal processes including metapopulations and a range of migratory patterns. It can accommodate different kinds of age structures, forms of population growth, dispersal, nomadism and migration, and alternative life-history strategies. Our objective was to link three general elements common to all spatially structured populations (space, time and movement) under a single mathematical framework. To do this, we adopt a network modeling approach. The spatial structure of a population is represented by a weighted and directed network. Each node and each edge has a set of attributes which vary through time. The dynamics of our network-based population is modeled with discrete time steps. Using both theoretical and real-world examples, we show how common elements recur across species with disparate movement strategies and how they can be combined under a unified mathematical framework. We illustrate how metapopulations, various migratory patterns, and nomadism can be represented with this modeling approach. We also apply our network-based framework to four organisms spanning a wide range of life histories, movement patterns, and carrying capacities. General computer code to implement our framework is provided, which can be applied to almost any spatially structured population. This framework contributes to our theoretical understanding of population dynamics and has practical management applications, including understanding the impact of perturbations on population size, distribution, and movement patterns. By working within a common framework, there is less chance
Modeling the brain morphology distribution in the general aging population
Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.
2016-03-01
Both normal aging and neurodegenerative diseases such as Alzheimer's disease cause morphological changes of the brain. To better distinguish between normal and abnormal cases, it is necessary to model changes in brain morphology owing to normal aging. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general aging population. The method is applied to 1000 subjects from a large population imaging study in the elderly, from which 900 were used to train the model and 100 were used for testing. The results of the 100 test subjects show that the model generalizes to subjects outside the model population. Smooth percentile curves showing the brain morphology changes as a function of age and spatiotemporal atlases derived from the model population are publicly available via an interactive web application at agingbrain.bigr.nl.
Numerical Hydrodynamics and Magnetohydrodynamics in General Relativity
Directory of Open Access Journals (Sweden)
Font José A.
2008-09-01
Full Text Available This article presents a comprehensive overview of numerical hydrodynamics and magnetohydrodynamics (MHD in general relativity. Some significant additions have been incorporated with respect to the previous two versions of this review (2000, 2003, most notably the coverage of general-relativistic MHD, a field in which remarkable activity and progress has occurred in the last few years. Correspondingly, the discussion of astrophysical simulations in general-relativistic hydrodynamics is enlarged to account for recent relevant advances, while those dealing with general-relativistic MHD are amply covered in this review for the first time. The basic outline of this article is nevertheless similar to its earlier versions, save for the addition of MHD-related issues throughout. Hence, different formulations of both the hydrodynamics and MHD equations are presented, with special mention of conservative and hyperbolic formulations well adapted to advanced numerical methods. A large sample of numerical approaches for solving such hyperbolic systems of equations is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. As previously stated, a comprehensive summary of astrophysical simulations in strong gravitational fields is also presented. These are detailed in three basic sections, namely gravitational collapse, black-hole accretion, and neutron-star evolutions; despite the boundaries, these sections may (and in fact do overlap throughout the discussion. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances in the formulation of the gravitational field, hydrodynamics and MHD equations and the numerical methodology designed to solve them. To keep the length of this article reasonable
Are elderly dependency ratios associated with general population suicide rates?
Shah, Ajit
2011-05-01
The elderly population size is increasing worldwide due to falling birth rates and increasing life expectancy. It has been hypothesized that as the elderly dependency ratio (the ratio of those over the age of 65 years to those under 65) increases, there will be fewer younger people available to care for older people and this, in turn, will increase the burden on younger carers with increased levels of psychiatric morbidity leading to an increase in general population suicide rates. A cross-national study examining the relationship between elderly dependency ratios and general population suicide rates was conducted using data from the World Health Organization and the United Nations websites. The main findings were of a significant and independent positive correlation between elderly dependency ratios and general population suicide rates in both genders. The contribution of cross-national differences in psychiatric morbidity in younger carers on general population suicide rates requires further study. The prevalence of psychiatric morbidity in younger carers of older people should be examined by: (i) cross-national studies using standardized measures of psychiatric morbidity that are education-free, culture-fair and language-fair; and (ii) within-country longitudinal studies with changing elderly dependency ratios over time.
An Introduction to General Relativity and Cosmology
International Nuclear Information System (INIS)
Wainwright, John
2007-01-01
The present volume is an introduction to general relativity and cosmology, at a level suitable for beginning graduate students or advanced undergraduates. The book consists of two main parts, the first entitled 'Elements of differential geometry', and the second 'The theory of gravitation'. Chapters 2-7, part I, introduce the basic ideas of differential geometry in a general setting, and are based on previously unpublished notes by one of the authors. On the one hand, the treatment is modern in that it uses a 'top-down' approach, i.e. starting with general differentiable manifolds, and deferring the introduction of a metric tensor until after the notions of affine connection and curvature have been introduced. On the other hand, the treatment is classical in that it relies heavily, though not exclusively, on index notation. The general material, chapters 1-7, is then followed by four more specialized chapters dealing with matters of specific interest for general relativity. Part II deals with general relativity and cosmology. The basic assumptions of the theory and its application to spherically symmetric gravitational fields are discussed in two chapters, and there is some historical material and motivation for the basic assumptions at the beginning of the book. The final chapter contains a detailed discussion of the Kerr solution. But the main emphasis in part II is on relativistic cosmology, in particular the analysis of cosmological models more general than the familiar Friedmann-Lemaitre (FL) models. The material on cosmology begins with a discussion of relativistic hydrodynamics and thermodynamics. The kinematical quantities (rate of expansion, shear, etc, of a timelike congruence) are introduced and their evolution equations are derived. There follows a description of the fluid model of the Universe and optical observations in such a model, within the framework of a general spacetime geometry. The discussion is subsequently specialized to the Robertson
Impact of Multidetector Computerized Tomography (MDCT) On The General Population
Energy Technology Data Exchange (ETDEWEB)
Leite, B.B.; Ribeiro, N.C. [Servico de Radiologia, Hospital de Curry Cabral, Rua da Beneficencia, 8, 1069-166 Lisboa (Portugal)
2009-05-15
Multidetector computerized tomography (MDCT) appeared in the early 1990s, as a technological evolution of computerized tomography. As one would expect, the evolution continues and, each year, more powerful equipments appear, with new medical applications. However, the general use of this technique has lead to the dramatic increase on the general population irradiation. Special concern is required regarding the most vulnerable groups, like the pediatric population, the pregnant and the young female. Due to a larger awareness of this irradiation risks, some initiatives have been developed, coming from different areas, aiming to maximize the benefit to risk ratio of MDCT. (author)
Energy conditions and stability in general relativity
International Nuclear Information System (INIS)
Hall, G.S.
1982-01-01
The dominant energy condition in general relativity theory, which says that every observer measures a nonnegative local energy density and a nonspacelike local energy flow, is examined in connection with the types of energy-momentum tensor it permits. The condition that the energy-momentum tensor be ''stable'' in obeying the dominant energy conditions is then defined in terms of a suitable topology on the set of energy-momentum tensors on space-time and the consequences are evaluated and discussed. (author)
Weak field approximation of new general relativity
International Nuclear Information System (INIS)
Fukui, Masayasu; Masukawa, Junnichi
1985-01-01
In the weak field approximation, gravitational field equations of new general relativity with arbitrary parameters are examined. Assuming a conservation law delta sup(μ)T sub(μν) = 0 of the energy-momentum tensor T sub(μν) for matter fields in addition to the usual one delta sup(ν)T sub(μν) = 0, we show that the linearized gravitational field equations are decomposed into equations for a Lorentz scalar field and symmetric and antisymmetric Lorentz tensor fields. (author)
The mathematical theory of general relativity
Katkar, L N
2014-01-01
This book is prepared for M. Sc. Students of Mathematics and Physics. The aim of writing this book is to give the reader a feeling for the necessity and beauty of the laws of general relativity. The contents of the book will attract both mathematicians and physicists which provides motivation and applications of many ideas and powerful mathematical methods of modern analysis and differential geometry. An attempt has been made to make the presentation comprehensive, rigorous and yet simple. Most calculations and transformations have been carried out in great detail. KEY FEATURE: Numerous solved examples using the well known mathematical techniques viz., the tensors and the differential forms in each chapter.
Tests of General Relativity with GW150914
Abbott, B. P.; Abbott, R.; Abernathy, M. R.; Adhikari, R. X.; Anderson, S. B.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Cahillane, C.
2016-01-01
The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant’s mass and spin, as determined fro...
New Area Law in General Relativity.
Bousso, Raphael; Engelhardt, Netta
2015-08-21
We report a new area law in general relativity. A future holographic screen is a hypersurface foliated by marginally trapped surfaces. We show that their area increases monotonically along the foliation. Future holographic screens can easily be found in collapsing stars and near a big crunch. Past holographic screens exist in any expanding universe and obey a similar theorem, yielding the first rigorous area law in big bang cosmology. Unlike event horizons, these objects can be identified at finite time and without reference to an asymptotic boundary. The Bousso bound is not used, but it naturally suggests a thermodynamic interpretation of our result.
Anholonomic Cauchy problem in general relativity
International Nuclear Information System (INIS)
Stachel, J.
1980-01-01
The Lie derivative approach to the Cauchy problem in general relativity is applied to the evolution along an arbitrary timelike vector field for the case where the dynamical degrees of freedom are chosen as the (generally anholonomic) metric of the hypersurface elements orthogonal to the vector field. Generalizations of the shear, rotation, and acceleration are given for a nonunit timelike vector field, and applied to the three-plus-one breakup of the Riemann tensor into components parallel and orthogonal to the vector field, resulting in the anholonomic Gauss--Codazzi equations. A similar breakup of the Einstein field equations results in the form of the constraint and evolution equations for the anholonomic case. The results are applied to the case of a space--time with a timelike Killing vector field (stationary field) to demonstrate their utility. Other possible applications, such as in the numerical integration of the field equations, are mentioned. Definitions are given of three-index shear, rotation, and acceleration tensors, and their use in a two-plus-two decomposition of the Riemann tensor and field equations is indicated
Introduction to general relativity and cosmology
Berger, Mitchell A
2018-01-01
The textbook aims to present general relativity and modern cosmology in a friendly form suitable for advanced undergraduates. The text begins with a self-contained introduction to the theory of manifolds and then develops the tools needed to understand curved spaces and curved spacetimes. Special relativity can then be understood in a geometrical context, bypassing some of the difficulties students have when encountering relativistic effects (e.g. time dilation and length contraction) for the first time. The theory of curvature and its effects leads to the Einstein field equations and its classic tests in the precession of Mercury and the deflection of starlight. The second part of the book covers modern cosmology, starting with the evolution equations for the expansion of the universe. The microwave background, evidence for dark matter, and the clustering of galaxies are examined in detail.
Mechanics of extended masses in general relativity
International Nuclear Information System (INIS)
Harte, Abraham I
2012-01-01
The 'external' or 'Right' motion of extended bodies is studied in general relativity. Compact material objects of essentially arbitrary shape, spin, internal composition and velocity are allowed as long as there is no direct (non-gravitational) contact with other sources of stress-energy. Physically reasonable linear and angular momenta are proposed for such bodies and exact equations describing their evolution are derived. Changes in the momenta depend on a certain 'effective metric' that is closely related to a non-perturbative generalization of the Detweiler-Whiting R-field originally introduced in the self-force literature. If the effective metric inside a self-gravitating body can be adequately approximated by an appropriate power series, the instantaneous gravitational force and torque exerted on it is shown to be identical to the force and torque exerted on an appropriate test body moving in the effective metric. This result holds to all multipole orders. The only instantaneous effect of a body's self-field is to finitely renormalize the 'bare' multipole moments of its stress-energy tensor. The MiSaTaQuWa expression for the gravitational self-force is recovered as a simple application. A gravitational self-torque is obtained as well. Lastly, it is shown that the effective metric in which objects appear to move is approximately a solution to the vacuum Einstein equation if the physical metric is an approximate solution to Einstein's equation linearized about a vacuum background. (paper)
Optical drift effects in general relativity
Korzyński, Mikołaj; Kopiński, Jarosław
2018-03-01
We consider the question of determining the optical drift effects in general relativity, i.e. the rate of change of the apparent position, redshift, Jacobi matrix, angular distance and luminosity distance of a distant object as registered by an observer in an arbitrary spacetime. We present a fully relativistic and covariant approach, in which the problem is reduced to a hierarchy of ODE's solved along the line of sight. The 4-velocities and 4-accelerations of the observer and the emitter and the geometry of the spacetime along the line of sight constitute the input data. We build on the standard relativistic geometric optics formalism and extend it to include the time derivatives of the observables. In the process we obtain two general, non-perturbative relations: the first one between the gravitational lensing, represented by the Jacobi matrix, and the apparent position drift, also called the cosmic parallax, and the second one between the apparent position drift and the redshift drift. The applications of the results include the theoretical study of the drift effects of cosmological origin (so-called real-time cosmology) in numerical or exact Universe models.
Kinematics in special and general relativity
International Nuclear Information System (INIS)
Woodside, R.W.M.
1979-05-01
This thesis investigates the problem of motion for extended bodies from the viewpoint of classical field theory, where the classical field is the body's energy-momentum or matter tensor. In special relativity a symmetric and divergence-free matter tensor combined with inertial frames is used to generate a kinematics for extended bodies. In general relativity the author suggests an analogous kinematics and applies it to the simplest non-trivial example of static, spherical stars, looking for special sets of vector fields whose matter currents are conserved. Such a set of ten vector fields defines a special frame, and integrals of the conserved matter currents define ten momenta whcih give the kinematics. Application of de Rham cohomology theory shows that the conserved matter currents for isolated bodies will have mechanical potentials which enable the momenta to be found from flux integrals evaluated in the vacuum region surrounding the body. These potentials contain the full Riemann curvature, allowing a body's general relativistic momenta to be determined by its vacuum graviational field
Stroke Awareness in the General Population: A Study from Jordan ...
African Journals Online (AJOL)
Purpose: To assess the awareness level of the Jordanian general population regarding the definition, risk factors, signs and symptoms, and consequences of stroke. Methods: This was a cross-sectional study. The questionnaire was handed to participants by trained students, the participants were chosen randomly from ...
Heritability of autistic traits in the general population.
Hoekstra, R.A.; Bartels, M.; Verweij, C.J.H.; Boomsma, D.I.
2007-01-01
Objective: To explore genetic and environmental influences on individual differences in autistic traits in early adulthood and to test if there is assortative mating (non-random partner choice) for autistic traits in the general population. Design: Twin family study using structural equation
Post-operative urinary retention in a general surgical population
DEFF Research Database (Denmark)
Dreijer, Bjørn; Møller, Morten H; Bartholdy, Jens
2011-01-01
Post-operative urine retention is a frequent and serious complication. The aims of this study were to evaluate the prevalence of post-operative urinary retention in a general surgical population and to identify the perioperative risk factors for developing this condition....
Kinematics of relative motion of test particles in general relativity
International Nuclear Information System (INIS)
Bazanski, S.L.
1977-01-01
A detailed mathematical study of the concept of geodesic deviation in pseudo-riemannian geometry is presented. A generalization of this concept to geodesic deviations of a higher order is then introduced and the second geodesic deviation is investigated in some detail. A geometric interpretation of the set of generalized geodesic deviations is given and applied in general relativity to determine a covariant and local description (with a desired order of accuracy) of test motions which take place in a certain finite neighbourhood of a given world line of an observer. The proper time evolution of two other objects related to geodesic deviation is also discussed: the space separation vector and the telescopic vector. This last name is given here to a field of null vectors along observer's world line which always point towards the same adjacent world line. The telescopic equations allow to determine the evolution of the frequency shift of electromagnetic radiation sent from and received on neighbouring world lines. On the basis of these equations also certain relations have been derived which connect the frequencies or frequency shifts with the curvature of space-time
An elementary course on general relativity
International Nuclear Information System (INIS)
Regge, T.
1983-01-01
This report gives an informal account of the theory of general relativity, for non-specialists. It does not contain any detailed technical expose of tensor calculus but relies instead on a number of intuitive arguments. After a brief historical introduction the notion of curvature is developed, first in two dimensions (as done originally by Gauss) and then in higher dimensions, following the ideas of Riemann. This curvature is then related to quantities of physical interest through the following steps: i) The equality of gravitational and inertial masses is discussed and presented as the ''weak equivalence principle''. ii) This is then extended to the ''strong equivalence principle'' according to the original programme of Einstein. iii) The ''strong equivalence principle'' implies the existence of a local inertial observer in any point of space-time. In a sufficiently small region of space-time this observer will not sense any gravitational field. iv) In a larger region the observer will, however, sense residual tidal forces. These forces are identified with the curvature of spacetime, to achieve a direct geometrical interpretation of gravity. v) Finally certain curvature components are related to the distribution of matter through Einstein's field equations. Section 4 contains a discussion of the classical tests of the theory and of the possibility of detecting gravitational waves. Sections 5 and 6 deal with cosmology and with the possible extension of the theory along the lines of the original ideas of Einstein, with emphasis on the dimensional reduction techniques of current interest. (orig.)
General Relativity solutions in modified gravity
Motohashi, Hayato; Minamitsuji, Masato
2018-06-01
Recent gravitational wave observations of binary black hole mergers and a binary neutron star merger by LIGO and Virgo Collaborations associated with its optical counterpart constrain deviation from General Relativity (GR) both on strong-field regime and cosmological scales with high accuracy, and further strong constraints are expected by near-future observations. Thus, it is important to identify theories of modified gravity that intrinsically possess the same solutions as in GR among a huge number of theories. We clarify the three conditions for theories of modified gravity to allow GR solutions, i.e., solutions with the metric satisfying the Einstein equations in GR and the constant profile of the scalar fields. Our analysis is quite general, as it applies a wide class of single-/multi-field scalar-tensor theories of modified gravity in the presence of matter component, and any spacetime geometry including cosmological background as well as spacetime around black hole and neutron star, for the latter of which these conditions provide a necessary condition for no-hair theorem. The three conditions will be useful for further constraints on modified gravity theories as they classify general theories of modified gravity into three classes, each of which possesses i) unique GR solutions (i.e., no-hair cases), ii) only hairy solutions (except the cases that GR solutions are realized by cancellation between singular coupling functions in the Euler-Lagrange equations), and iii) both GR and hairy solutions, for the last of which one of the two solutions may be selected dynamically.
Dynamical laws of superenergy in general relativity
International Nuclear Information System (INIS)
Gomez-Lobo, Alfonso GarcIa-Parrado
2008-01-01
The Bel and Bel-Robinson tensors were introduced nearly 50 years ago in an attempt to generalize to gravitation the energy-momentum tensor of electromagnetism. This generalization was successful from the mathematical point of view because these tensors share mathematical properties which are remarkably similar to those of the energy-momentum tensor of electromagnetism. However, the physical role of these tensors in general relativity has remained obscure and no interpretation has achieved wide acceptance. In principle, they cannot represent energy and the term superenergy has been coined for the hypothetical physical magnitude lying behind them. In this work, we try to shed light on the true physical meaning of superenergy by following the same procedure which enables us to give an interpretation of the electromagnetic energy. This procedure consists in performing an orthogonal splitting of the Bel and Bel-Robinson tensors and analyzing the different parts resulting from the splitting. In the electromagnetic case such splitting gives rise to the electromagnetic energy density, the Poynting vector and the electromagnetic stress tensor, each of them having a precise physical interpretation which is deduced from the dynamical laws of electromagnetism (Poynting theorem). The full orthogonal splitting of the Bel and Bel-Robinson tensors is more complex but, as expected, similarities with electromagnetism are present. Also the covariant divergence of the Bel tensor is analogous to the covariant divergence of the electromagnetic energy-momentum tensor and the orthogonal splitting of the former is found. The ensuing equations are to the superenergy what the Poynting theorem is to electromagnetism. Some consequences of these dynamical laws of superenergy are explored, among them the possibility of defining superenergy radiative states for the gravitational field
On multipole moments in general relativity
International Nuclear Information System (INIS)
Hoenselaers, C.
1986-01-01
In general situations, involving gravitational waves the question of multiple moments in general relativity restricts the author to stationary axisymmetric situations. Here it has been shown that multipole moments, a set of numbers defined at spatial infinity as far away from the source as possible, determine a solution of Einstein's equations uniquely. With the rather powerful methods for generating solutions one might hope to get solutions with predefined multipole moments. Before doing so, however, one needs an efficient algorithm for calculating the moments of a given solution. Chapter 2 deals with a conjecture pertaining to such a calculational procedure and shows it to be not true. There is another context in which multipole moments are important. Consider a system composed of several objects. To separate, if possible, the various parts of their interaction, one needs a definition for multipole moments of individual members of a many body system. In spite of the fact that there is no definition for individual moments, with the exception of mass and angular momentum, Chapter 3 shows what can be done for the double Kerr solution. The authors can identify various terms in he interaction of two aligned Kerr objects and show that gravitational spin-spin interaction is indeed proportional to the product of the angular momenta
Victories and defeats in general relativity theory
International Nuclear Information System (INIS)
Moeller, C.
1977-01-01
Only within the last 20 years has it been possible to conduct far-reaching experimental tests of the validity of Einstein's General Relativity Theory. Experimental confirmation in some fields is embarrassed by considerable difficulties in applying the theory to cosmic systems, which indicate that such major systems lie at the limit of the theory's applicability. The lecture here reproduced discusses both the successes and the limitations of the theory, starting with its replacement of the absolute space-time theory of Newton and its historical replacement by the relativistic gravitational postulates of Einstein which, in spite of its more complicated postulates, nevertheless introduced a great simplicity and comprehensiveness into the overall conception of nature. This theoretical 'beauty', however, can only be trusted if vindicated experimentally, which has to a considerable extent proved to be the case. For weak fields Newtonian and Einsteinian concepts coincide, while for stronger fields, and velocities not far from that of light, Einstein's theory is superior, giving,for example, an excellent correspondence with the precession of the perehelion of Mercury. On a larger scale, however, the theory appears to lead to conclusions which would invalidate the very concepts of space and time, even within a finite time-interval. A more generalized theory seems to be required. (A.D.N.)
Rotating Quark Stars in General Relativity
Directory of Open Access Journals (Sweden)
Enping Zhou
2018-03-01
Full Text Available We have built quasi-equilibrium models for uniformly rotating quark stars in general relativity. The conformal flatness approximation is employed and the Compact Object CALculator (cocal code is extended to treat rotating stars with surface density discontinuity. In addition to the widely used MIT bag model, we have considered a strangeon star equation of state (EoS, suggested by Lai and Xu, that is based on quark clustering and results in a stiff EoS. We have investigated the maximum mass of uniformly rotating axisymmetric quark stars. We have also built triaxially deformed solutions for extremely fast rotating quark stars and studied the possible gravitational wave emission from such configurations.
Motivations for antigravity in General Relativity
Energy Technology Data Exchange (ETDEWEB)
Chardin, G. [DSM/DAPNIA/SPP, CEN-Saclay (France)
1997-08-15
We present arguments showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, we conjecture a property of perfect stigmatism through Kerr wormholes which allows General Relativity to mimic antigravity. Kerr wormholes would then act as 'supermirrors' reversing the C, P and T images of an object seen through it. This interpretation is subject to several experimental tests and able to provide an explanation, without any free parameter, of the 'CP' violation observed in the neutral kaon system.
Motivations for antigravity in General Relativity
International Nuclear Information System (INIS)
Chardin, G.
1997-01-01
We present arguments showing that it is natural to interpret the negative mass part of the Kerr solution as representing the geometry experienced by antimatter. The C, P and T discrete transformations are considered for this geometry. The C and T properties of the proposed identification are found to be in agreement with the usual representation of antimatter. In addition, we conjecture a property of perfect stigmatism through Kerr wormholes which allows General Relativity to mimic antigravity. Kerr wormholes would then act as 'supermirrors' reversing the C, P and T images of an object seen through it. This interpretation is subject to several experimental tests and able to provide an explanation, without any free parameter, of the 'CP' violation observed in the neutral kaon system
On thick domain walls in general relativity
Goetz, Guenter; Noetzold, Dirk
1989-01-01
Planar scalar field configurations in general relativity differ considerably from those in flat space. It is shown that static domain walls of finite thickness in curved space-time do not possess a reflection symmetry. At infinity, the space-time tends to the Taub vacuum on one side of the wall and to the Minkowski vacuum (Rindler space-time) on the other. Massive test particles are always accelerated towards the Minkowski side, i.e., domain walls are attractive on the Taub side, but repulsive on the Minkowski side (Taub-vacuum cleaner). It is also proved that the pressure in all directions is always negative. Finally, a brief comment is made concerning the possibility of infinite, i.e., bigger than horizon size, domain walls in our universe. All of the results are independent of the form of the potential V(phi) greater than or equal to 0 of the scalar field phi.
Modifiable factors associated with copeptin concentration: a general population cohort.
van Gastel, Maatje D A; Meijer, Esther; Scheven, Lieneke E; Struck, Joachim; Bakker, Stephan J L; Gansevoort, Ron T
2015-05-01
Vasopressin plays an important role in maintaining volume homeostasis. However, recent studies suggest that vasopressin also may play a detrimental role in the progression of chronic kidney disease. It therefore is of interest to identify factors that influence vasopressin concentration, particularly modifiable ones. Cross-sectional analyses. Data used are from participants in a large general-population cohort study (Prevention of Renal and Vascular Endstage Disease [PREVEND]). Patients with a missing copeptin value (n=888), nonfasting blood sample (n=495), missing or assumed incorrect 24-hour urine collection (n=388), or heart failure (n=20) were excluded, leaving 6,801 participants for analysis. Identification of lifestyle- and diet-related factors that are associated with copeptin concentration. Copeptin concentration as surrogate for vasopressin. Copeptin was measured by an immunoluminometric assay as a surrogate for vasopressin. Associations were assessed in uni- and multivariable linear regression analyses. Median copeptin concentration was 4.7 (IQR, 2.9-7.6) pmol/L. When copeptin was studied as a dependent variable, the final stepwise backward model revealed associations with higher copeptin concentrations for lower 24-hour urine volume (P firm conclusions on cause-effect relationships. Important lifestyle- and diet-related factors associated with copeptin concentration are current smoking, alcohol use, protein and potassium intake, and particularly fluid and sodium intake. These data form a rationale to investigate whether intervening on these factors results in a lower vasopressin concentration with concomitant beneficial renal effects. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
A general theory of quantum relativity
International Nuclear Information System (INIS)
Minic, Djordje; Tze, C.-H.
2004-01-01
The geometric form of standard quantum mechanics is compatible with the two postulates: (1) the laws of physics are invariant under the choice of experimental setup and (2) every quantum observation or event is intrinsically statistical. These postulates remain compatible within a background independent extension of quantum theory with a local intrinsic time implying the relativity of the concept of a quantum event. In this extension the space of quantum events becomes dynamical and only individual quantum events make sense observationally. At the core of such a general theory of quantum relativity is the three-way interplay between the symplectic form, the dynamical metric and non-integrable almost complex structure of the space of quantum events. Such a formulation provides a missing conceptual ingredient in the search for a background independent quantum theory of gravity and matter. The crucial new technical element in our scheme derives from a set of recent mathematical results on certain infinite-dimensional almost Kahler manifolds which replace the complex projective spaces of standard quantum mechanics
Early detection of cancer in the general population
DEFF Research Database (Denmark)
Pedersen, J W; Gentry-Maharaj, A; Fourkala, E-O
2013-01-01
Background:Recent reports from cancer screening trials in high-risk populations suggest that autoantibodies can be detected before clinical diagnosis. However, there is minimal data on the role of autoantibody signatures in cancer screening in the general population.Methods:Informative p53 peptides...... preclinical disease and may be of value in cancer screening. In colorectal cancer screening in particular, where the current need is to improve compliance, it suggests that p53 autoantibodies may contribute towards risk stratification.British Journal of Cancer advance online publication, 20 November 2012; doi...
Singular Null Hypersurfaces in General Relativity
International Nuclear Information System (INIS)
Dray, T
2006-01-01
Null hypersurfaces are a mathematical consequence of the Lorentzian signature of general relativity; singularities in mathematical models usually indicate where the interesting physics takes place. This book discusses what happens when you combine these ideas. Right from the preface, this is a no-nonsense book. There are two principal approaches to singular shells, one distributional and the other 'cut and paste'; both are treated in detail. A working knowledge of GR is assumed, including familiarity with null tetrads, differential forms, and 3 + 1 decompositions. Despite my own reasonably extensive, closely related knowledge, there was material unfamiliar to me already in chapter 3, although I was reunited with some old friends in later chapters. The exposition is crisp, with a minimum of transition from chapter to chapter. In fact, my main criticism is that there is no clear statement of the organization of the book, nor is there an index. Everything is here, and the story is compelling if you know what to look for, although it is less easy to follow the story if you are not already familiar with it. But this is really a book for experts, and the authors certainly qualify, having played a significant role in developing and extending the results they describe. It is also entirely appropriate that the book is dedicated to Werner Israel, who pioneered the thin-shell approach to (non-null) singular surfaces and later championed the use of similar methods for analysing null shells. After an introductory chapter on impulsive signals, the authors show how the Bianchi identities can be used to classify spacetimes with singular null hypersurfaces. This approach, due to the authors, generalizes the framework originally proposed by Penrose. While astrophysical applications are discussed only briefly, the authors point out that detailed physical characteristics of signals from isolated sources can be determined in this manner. In particular, they describe the behaviour of
Directory of Open Access Journals (Sweden)
Stenhagen M
2014-10-01
Full Text Available Magnus Stenhagen, Henrik Ekström, Eva Nordell, Sölve Elmståhl Department of Health Sciences, Division of Geriatric Medicine, Lund University, Skåne University Hospital, Malmö, Sweden Objectives: To determine the relationship between long-term change in activities of daily living (ADL and falls in the elderly and to identify characteristics of groups at risk for falls.Methods: This was a 6-year, prospective cohort study using data from the Good Aging in Skåne study in southern Sweden, involving 1,540 elderly subjects, including the oldest-old (age, 60–93 years. The subjects were recruited from the general population. ADL was measured at a baseline and follow-up assessment, using Sonn and Åsberg’s revised scale and the ADL staircase. Falls were recorded in a period of 6 months before the follow-up assessment. The association between falls and change in ADL was calculated using adjusted, multiple logistic regression analysis and presented in odds ratios (ORs.Results: Thirteen percent of the study population reported one or several falls in the measured period. Over the course of 6 years, one in four participants changed their ADL status, and parts of this category had an increased risk for falls compared with those who stayed independent in ADL or who had no change in the ADL staircase. Groups with different characteristics had a prominent risk for falls: those with a reduction of two to eight steps in the ADL staircase (OR, 4.05; 95% confidence interval [CI], 1.62–10.11 and those becoming independent from dependency in instrumental ADL (OR, 4.13; 95% CI, 1.89–9.00. The former group had advanced age with a greater burden of cognitive impairment, gait disability, arrhythmia, and fall risk medications. The latter group had a higher prevalence of ischemic heart disease and low walking speed. Conclusion: Both deterioration and improvement in ADL over the course of 6 years increased the risk for falls in a general elderly population
Axially symmetric Lorentzian wormholes in general relativity
International Nuclear Information System (INIS)
Schein, F.
1997-11-01
The field equations of Einstein's theory of general relativity, being local, do not fix the global structure of space-time. They admit topologically non-trivial solutions, including spatially closed universes and the amazing possibility of shortcuts for travel between distant regions in space and time - so-called Lorentzian wormholes. The aim of this thesis is to (mathematically) construct space-times which contain traversal wormholes connecting arbitrary distant regions of an asymptotically flat or asymptotically de Sitter universe. Since the wormhole mouths appear as two separate masses in the exterior space, space-time can at best be axially symmetric. We eliminate the non-staticity caused by the gravitational attraction of the mouths by anchoring them by strings held at infinity or, alternatively, by electric repulsion. The space-times are obtained by surgically grafting together well-known solutions of Einstein's equations along timelike hypersurfaces. This surgery naturally concentrates a non-zero stress-energy tensor on the boundary between the two space-times which can be investigated by using the standard thin shell formalism. It turns out that, when using charged black holes, the provided constructions are possible without violation of any of the energy conditions. In general, observers living in the axially symmetric, asymptotically flat (respectively asymptotically de Sitter) region axe able to send causal signals through the topologically non-trivial region. However, the wormhole space-times contain closed timelike curves. Because of this explicit violation of global hyperbolicity these models do not serve as counterexamples to known topological censorship theorems. (author)
Cardiovascular morbidity in COPD: A study of the general population
DEFF Research Database (Denmark)
Lange, Peter; Møgelvang, Rasmus; Marott, Jacob Louis
2010-01-01
Although there are a number of studies on the coexistence of heart disease and COPD among patients acutely admitted to hospital, this relationship has not been accurately described in the general population. Especially data on the prevalence of both reduced lung function and impaired left.......4% for moderate COPD (GOLD stage 2) and 2.5% for severe and very severe COPD (GOLD stages 3+4). Individuals with COPD were older and had a higher prevalence of cardiovascular risk factors and a higher prevalence of cardiovascular diseases. Among the echocardiographical findings, only the presence of left...... ventricular hyperthrophy was significantly more frequent among individuals with COPD (17.7%) than among participants without COPD (12.1%.), yet this relationship was no longer significant after statistical adjustment for age and gender. In the general population, subjects with COPD have a higher prevalence...
Preventive psychosocial parental and school programmes in a general population
Löfgren, Hans O.
2017-01-01
Introduction Numerous preventive programmes have emerged, and need to be investigated to determine their effects on the normal population. Earlier studies have shown a decrease in depressive symptoms, positive effects on children’s disruptive behaviour problems, and an improvement in parental competence. About a fifth of the parents in previous studies had problem-oriented (targeted) reasons for enrolment, whereas the rest of the parents had general (universal) reasons. The results of those s...
Cortical processes of speech illusions in the general population.
Schepers, E; Bodar, L; van Os, J; Lousberg, R
2016-10-18
There is evidence that experimentally elicited auditory illusions in the general population index risk for psychotic symptoms. As little is known about underlying cortical mechanisms of auditory illusions, an experiment was conducted to analyze processing of auditory illusions in a general population sample. In a follow-up design with two measurement moments (baseline and 6 months), participants (n = 83) underwent the White Noise task under simultaneous recording with a 14-lead EEG. An auditory illusion was defined as hearing any speech in a sound fragment containing white noise. A total number of 256 speech illusions (SI) were observed over the two measurements, with a high degree of stability of SI over time. There were 7 main effects of speech illusion on the EEG alpha band-the most significant indicating a decrease in activity at T3 (t = -4.05). Other EEG frequency bands (slow beta, fast beta, gamma, delta, theta) showed no significant associations with SI. SIs are characterized by reduced alpha activity in non-clinical populations. Given the association of SIs with psychosis, follow-up research is required to examine the possibility of reduced alpha activity mediating SIs in high risk and symptomatic populations.
On the ultrarelativistic limit of general relativity
International Nuclear Information System (INIS)
Dautcourt, G.
1998-01-01
As is well-known, Newton's gravitational theory can be formulated as a four-dimensional space-time theory and follows as singular limit from Einstein's theory, if the velocity of light tends to the infinity. Here 'singular' stands for the fact, that the limiting geometrical structure differs from a regular Riemannian space-time. Geometrically, the transition Einstein → Newton can be viewed as an 'opening' of the light cones. This picture suggests that there might be other singular limits of Einstein's theory: Let all light cones shrink and ultimately become part of a congruence of singular world lines. The limiting structure may be considered as a null hypersurface embedded in a five-dimensional spacetime. While the velocity of light tends to zero here, all other velocities tend to the velocity of light. Thus one may speak of an ultrarelativistic limit of General Relativity. The resulting theory is as simple as Newton's gravitational theory, with the basic difference, that Newton's elliptic differential equation is replaced by essentially ordinary differential equations, with derivatives tangent to the generators of the singular congruence. The Galilei group is replaced by the Carroll group introduced by Levy-Leblond. We suggest to study near ultrarelativistic situations with a perturbational approach starting from the singular structure, similar to post-Newtonian expansions in the c → ∞ case. (author)
Direction dependent structures in general relativity
International Nuclear Information System (INIS)
Herberthson, M.
1993-01-01
This thesis deals with, within the theory of general relativity, asymptotic properties of certain types of space-times. Using conformal transformations, it is possible to describe asymptotic properties of a physical space-time in terms of the local behaviour of the new, rescaled space-time. One then uses so called direction dependent structures. We present two such structures and applications to them. One structure is used in the study of spacelike (or spatial) infinity. We discuss the asymptotic conditions on the gravitational and the electromagnetic field, especially the conditions put on directions corresponding to future and past null infinity. It is shown that these fields have desired physical properties. The other structure is used in connection with timelike infinity. Using this structure, we suggest a new definition of timelike infinity. This definition differs significantly from earlier definitions, and leads to the concept of asymptotically stationary space-times. We also suggest a definition of asymptotic flatness at future null infinity, and a definition of a black hole which is, in a sense, local. Both of these definitions fit nicely into the structure. (24 refs.)
General relativity invariance and string field theory
International Nuclear Information System (INIS)
Aref'eva, I.Ya.; Volovich, I.V.
1987-04-01
The general covariance principle in the string field theory is considered. The algebraic properties of the string Lie derivative are discussed. The string vielbein and spin connection are introduced and an action invariant under general co-ordinate transformation is proposed. (author). 18 refs
Gravitational Wave in Linear General Relativity
Cubillos, D. J.
2017-07-01
General relativity is the best theory currently available to describe the interaction due to gravity. Within Albert Einstein's field equations this interaction is described by means of the spatiotemporal curvature generated by the matter-energy content in the universe. Weyl worked on the existence of perturbations of the curvature of space-time that propagate at the speed of light, which are known as Gravitational Waves, obtained to a first approximation through the linearization of the field equations of Einstein. Weyl's solution consists of taking the field equations in a vacuum and disturbing the metric, using the Minkowski metric slightly perturbed by a factor ɛ greater than zero but much smaller than one. If the feedback effect of the field is neglected, it can be considered as a weak field solution. After introducing the disturbed metric and ignoring ɛ terms of order greater than one, we can find the linearized field equations in terms of the perturbation, which can then be expressed in terms of the Dalambertian operator of the perturbation equalized to zero. This is analogous to the linear wave equation in classical mechanics, which can be interpreted by saying that gravitational effects propagate as waves at the speed of light. In addition to this, by studying the motion of a particle affected by this perturbation through the geodesic equation can show the transversal character of the gravitational wave and its two possible states of polarization. It can be shown that the energy carried by the wave is of the order of 1/c5 where c is the speed of light, which explains that its effects on matter are very small and very difficult to detect.
The Concept of General Relativity is not Related to Reality
Kotas, Ronald
2015-04-01
The concept of general relativity is not related to reality. It is not real or factual Science. GR cannot account for objects falling to earth or for the weight of objects sitting on the earth. The Cavendish demonstration showing the attraction between two masses at right angles to earth's gravity, is not explained by GR. No one can prove the existence of ``space fabric.'' The concept of ``space time'' effects causing gravitational attraction between masses is wrong. Conservation law of energy - momentum does not exist in GR. LIGO fails in detecting ``gravity waves'' because there is no ``space fabric'' to transmit them. The Gravity B Probe data manipulated to show some effects, is not proof of ``space fabric.'' It is Nuclear Quantum Gravitation that provides clear definitive explanation of Gravity and Gravitation. It is harmonious with Newtonian and Quantum Mechanics, and Scientific Logic. Nuclear Quantum Gravitation has 10 clear, Scientific proofs and 21 more good indications. With this theory the Physical Forces are Unified. See: OBSCURANTISM ON EINSTEIN GRAVITATION? http://www.santilli-foundation.org/inconsistencies-gravitation.php and Einstein's Theory of Relativity versus Classical Mechanics, by Paul Marmet http://www.newtonphysics.on.ca/einstein/
[Daytime consequences of insomnia complaints in the French general population].
Ohayon, M M; Lemoine, P
2004-01-01
Insomnia is a frequent symptom in the general population; numerous studies have proven this. In the past years, classifications have gradually given more emphasis to daytime repercussions of insomnia and to their consequences on social and cognitive functioning. They are now integrated in the definition of insomnia and are used to quantify its severity. If the daytime consequences of insomnia are well known at the clinical level, there are few epidemiological data on this matter. The aim of this study was to assess the daytime repercussions of insomnia complaints in the general population of France. A representative sample (n=5,622) aged 15 or older was surveyed by telephone with the help of the sleep-EVAL expert system, a computer program specially designed to evaluate sleep disorders and to manage epidemiological investigations. Interviews have been completed for 80.8% of the solicited subjects (n=5,622). The variables considered comprised insomnia and its daytime repercussions on cognitive functioning, affective tone, daytime sleepiness and diurnal fatigue. Insomnia was found in 18.6% of the sample. The prevalence was higher in women (22.4%) than in men (14.5%, psleep. Nearly 75% of insomnia complainers reported having a disrupted sleep or waking up too early in the morning and about 40% said they had a non-restorative sleep. Repercussions on daytime functioning were reported by most insomnia subjects (67%). Repercussions on cognitive functioning changed according age, number of insomnia symptoms and the use of a psychotropic medication. A decreased efficiency was more likely to be reported by subjects between 15 and 44 years of age (OR: 2.9), those using a psychotropic (OR: 1.5), those reporting at least three insomnia symptoms (OR: 1.4) and women (OR: 1.4). The highest probability of the appearance of concentration difficulties was found in subjects younger than 65 Years, having a depressive disorder and using a psychotropic (15-44 years: OR 19.1; 45-64 years
Bonsaksen, Tore; Lerdal, Anners; Heir, Trond; Ekeberg, Øivind; Skogstad, Laila; Grimholt, Tine K; Schou-Bredal, Inger
2018-02-01
General self-efficacy (GSE) refers to optimistic self-beliefs of being able to perform and control behaviors, and is linked with various physical and mental health outcomes. Measures of self-efficacy are commonly used in health research with clinical populations, but are less explored in relationship to sociodemographic characteristics in general populations. This study investigated GSE in relation to sociodemographic characteristics in the general population in Norway. As part of a larger national survey, the GSE scale was administered to a general population sample, and 1787 out of 4961 eligible participants (response rate 36%) completed the scale. Group comparisons were conducted using independent t-tests and one-way analyses of variance. Linear regression analysis was used to examine factors independently associated with GSE. GSE was lower for older compared to younger participants ( p employment were independently associated with higher GSE. Age moderated the associations between gender and employment on one hand, and GSE on the other. The association between being male and having higher GSE was more pronounced in younger age, as was the association between being employed and having higher GSE. Male gender and being employed were related to higher GSE among persons in the general population in Norway, and these associations were stronger among persons of younger age. The findings are considered fairly representative for the Norwegian population.
Border Collision Bifurcations in a Generalized Model of Population Dynamics
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Lilia M. Ladino
2016-01-01
Full Text Available We analyze the dynamics of a generalized discrete time population model of a two-stage species with recruitment and capture. This generalization, which is inspired by other approaches and real data that one can find in literature, consists in considering no restriction for the value of the two key parameters appearing in the model, that is, the natural death rate and the mortality rate due to fishing activity. In the more general case the feasibility of the system has been preserved by posing opportune formulas for the piecewise map defining the model. The resulting two-dimensional nonlinear map is not smooth, though continuous, as its definition changes as any border is crossed in the phase plane. Hence, techniques from the mathematical theory of piecewise smooth dynamical systems must be applied to show that, due to the existence of borders, abrupt changes in the dynamic behavior of population sizes and multistability emerge. The main novelty of the present contribution with respect to the previous ones is that, while using real data, richer dynamics are produced, such as fluctuations and multistability. Such new evidences are of great interest in biology since new strategies to preserve the survival of the species can be suggested.
Stability of the frequent COPD exacerbator in the general population
DEFF Research Database (Denmark)
Reilev, Mette; Lykkegaard, Jesper; Halling, Anders
2017-01-01
Exacerbation frequency is central in treatment strategies for chronic obstructive pulmonary disease. However, whether chronic obstructive pulmonary disease patients from the general population with frequent exacerbations continue to have frequent exacerbations over an extended period of time is c...... considerably over time. This could hold implications for COPD treatment and challenge assumptions made about disease progression....... is currently unknown. In this study, we aimed to investigate the stability of the frequent exacerbator in a population-based setting. To this end, we conducted a nationwide register-based descriptive study with a 10-year follow-up period of chronic obstructive pulmonary disease patients with at least one...... obstructive pulmonary disease treatment guidelines and their practical application. CHRONIC OBSTRUCTIVE LUNG DISEASE: VARIATIONS IN DISEASE PROGRESSION: Patients with chronic obstructive pulmonary disease (COPD) who suffer from frequent exacerbations do not necessarily persist with such severity over time...
Directory of Open Access Journals (Sweden)
José Marcelo Soriano Viana
2003-12-01
Full Text Available Estimation of general and specific combining ability effects in a diallel analysis of cross-pollinating populations, including the selfed parents, is presented in this work. The restrictions considered satisfy the parametric values of the GCA and SCA effects. The method is extended to self-pollinating populations (suitable for other species, without the selfed parents. The analysis of changes in population means due to inbreeding (sensitivity to inbreeding also permits to assess the predominant direction of dominance deviations and the relative genetic variability in each parent population. The methodology was used to select popcorn populations for intra- and inter-population breeding programs and for hybrid production, developed at the Federal University of Viçosa, MG, Brazil. Two yellow pearl grain popcorn populations were selected.
Löwe, Bernd; Decker, Oliver; Müller, Stefanie; Brähler, Elmar; Schellberg, Dieter; Herzog, Wolfgang; Herzberg, Philipp Yorck
2008-03-01
The 7-item Generalized Anxiety Disorder Scale (GAD-7) is a practical self-report anxiety questionnaire that proved valid in primary care. However, the GAD-7 was not yet validated in the general population and thus far, normative data are not available. To investigate reliability, construct validity, and factorial validity of the GAD-7 in the general population and to generate normative data. Nationally representative face-to-face household survey conducted in Germany between May 5 and June 8, 2006. Five thousand thirty subjects (53.6% female) with a mean age (SD) of 48.4 (18.0) years. The survey questionnaire included the GAD-7, the 2-item depression module from the Patient Health Questionnaire (PHQ-2), the Rosenberg Self-Esteem Scale, and demographic characteristics. Confirmatory factor analyses substantiated the 1-dimensional structure of the GAD-7 and its factorial invariance for gender and age. Internal consistency was identical across all subgroups (alpha = 0.89). Intercorrelations with the PHQ-2 and the Rosenberg Self-Esteem Scale were r = 0.64 (P < 0.001) and r = -0.43 (P < 0.001), respectively. As expected, women had significantly higher mean (SD) GAD-7 anxiety scores compared with men [3.2 (3.5) vs. 2.7 (3.2); P < 0.001]. Normative data for the GAD-7 were generated for both genders and different age levels. Approximately 5% of subjects had GAD-7 scores of 10 or greater, and 1% had GAD-7 scores of 15 or greater. Evidence supports reliability and validity of the GAD-7 as a measure of anxiety in the general population. The normative data provided in this study can be used to compare a subject's GAD-7 score with those determined from a general population reference group.
Factors Related to Suicide in LGBT Populations.
Skerrett, Delaney Michael; Kõlves, Kairi; De Leo, Diego
2016-09-01
There is evidence of heightened vulnerability to nonfatal suicidal behaviors among LGBT populations yet a paucity of studies into fatal behaviors. The specific aim of this article was to identify factors related to suicide in LGBT individuals in Australia. The psychological autopsy (PA) method with a matched case-control study design was used. PA interviews were conducted with 27 next-of-kin of an LGBT person that had died by suicide. Three living LGBT controls per suicide case, matched by age and gender, were also interviewed. The key factors relating to suicide in LGBT people were a lack of acceptance by family and self (reflected in higher internalized homophobia and shame), negative feelings about own sexuality/gender, and dissatisfaction with appearance. LGBT people who died by suicide also tended to go through coming out milestones 2 years earlier than controls. There was a higher prevalence of aggressive behaviors and a more predominant history of physical and sexual abuse. Additionally, there was greater incidence of depression and anxiety and alcohol and substance use disorders. Specific predictive factors for suicide in LGBT populations in Australia were identified, including significantly poorer mental health outcomes and more violence across an array of measures.
DEFF Research Database (Denmark)
Hildebrandt, Per
2009-01-01
(General Practitioner) setting as in the acute setting. Supporting this use is a very strong prognostic value of the natriuretic peptides. This has been shown in as well heart failure as acute coronary syndromes, but also in the general population and in high-risk groups as patients with diabetes......, hypertension and coronary artery disease. This has of course raised interest for the use of the natriuretic peptides as a risk marker and for screening for heart failure with reduced systolic function in these populations. In symptomatic persons and in high risk populations, the natriuretic peptides have...... demonstrated a high sensitivity for ruling out the disease, if the right decision limits are choosen. Thus the number of normal echocardiographies can be reduced. More recently, the use in screening asymptomatic persons for left ventricular systolic dysfunction has gained more interest. In the unselected...
The tensorial conservation law in general relativity
International Nuclear Information System (INIS)
Zhao, M.G.
1984-01-01
A general tensorial conservation law is formulated by starting from the invariance of the gravitational Lagrangian density. Utilising this new formula, the author derives some reasonable results for the mass-energy distribution which are in accordance with the Newtonian formulae. (author)
Radiation protection training for diverse general employee populations
International Nuclear Information System (INIS)
Copenhaver, E.D.; Houser, B.S.
1986-01-01
Radiation protection training for the general employee at the Oak Ridge National Laboratory has undergone a great deal of restructuring in the last two years. The number of personnel totally dedicated to nuclear facilities is less than a fifth of our employees and the percentage of contracted employees who are dedicated radiation workers is much smaller. However, the aging of our facilities and increasing emphasis on environmental control means that everyone needs to understand the basics of radiation protection. In accordance with changing DOE guidelines and internal ORNL policies, greater emphasis has been placed on keeping training focused on current issues, training the total workforce, and requiring some type of testing or feedback mechanism. This report describes efforts to instill respect, but not fear, of radiation in the work environment. Flexible tools are being developed to meet this objective for several diverse general employee populations. Continuing efforts include consideration of computer-based training for retraining, developing additional modules for specialized groups and jobs, and testing/documentation appropriate to each population segment. 6 refs
Health Effects of Job Insecurity among Employees in Swiss General Population
Gianfranco DOMENIGHETTI; Barbara D'AVANZO; Brigitte BISIG
1999-01-01
Objectives. To investigate at national level the association between health and the social distress in which the whole employed population is plunged as a consequence of job insecurity. Design. Cross-sectional study. Setting. Switzerland. Subjects. Individuals working full or part time as employees drawn from a random sample (N=2024) of the Swiss general population interviewed by phone. Main outcome measures. Prevalence rates of ten self reported health and health related behaviour indicators...
Aldosterone and glomerular filtration--observations in the general population.
Hannemann, Anke; Rettig, Rainer; Dittmann, Kathleen; Völzke, Henry; Endlich, Karlhans; Nauck, Matthias; Wallaschofski, Henri
2014-03-10
Increasing evidence suggests that aldosterone promotes renal damage. Since data on the association between aldosterone and renal function in the general population are sparse, we chose to address this issue. We investigated the associations between the plasma aldosterone concentration (PAC) or the aldosterone-to-renin ratio (ARR) and the estimated glomerular filtration rate (eGFR) in a sample of adult men and women from Northeast Germany. A study population of 1921 adult men and women who participated in the first follow-up of the Study of Health in Pomerania was selected. None of the subjects used drugs that alter PAC or ARR. The eGFR was calculated according to the four-variable Modification of Diet in Renal Disease formula. Chronic kidney disease (CKD) was defined as an eGFR < 60 ml/min/1.73 m2. Linear regression models, adjusted for sex, age, waist circumference, diabetes mellitus, smoking status, systolic and diastolic blood pressures, serum triglyceride concentrations and time of blood sampling revealed inverse associations of PAC or ARR with eGFR (ß-coefficient for log-transformed PAC -3.12, p < 0.001; ß-coefficient for log-transformed ARR -3.36, p < 0.001). Logistic regression models revealed increased odds for CKD with increasing PAC (odds ratio for a one standard deviation increase in PAC: 1.35, 95% confidence interval: 1.06-1.71). There was no statistically significant association between ARR and CKD. Our study demonstrates that PAC and ARR are inversely associated with the glomerular filtration rate in the general population.
The 'Falling Box' method in general relativity
International Nuclear Information System (INIS)
Gladush, V.D.
1998-01-01
The problems of justification, generalization, and applicability of the 'falling box' method to obtained some exact solutions of the vacuum Einstein equations are investigated. The 'physical' inference of the Reissner-Nordstrom-de Sitter and Kerr metrics is shown. Explanation is given for the well-known relativistic phenomenon which consists in that gravity is created by the double density of the electrical field energy
General Information about AIDS-Related Lymphoma
... and treatment options. AIDS-related lymphoma is a disease in which malignant (cancer) cells form in the ... cord. The sample may also be checked for Epstein-Barr virus . This procedure is also called an LP ...
On ``minimally curved spacetimes'' in general relativity
Dadhich, Naresh
1997-01-01
We consider a spacetime corresponding to uniform relativistic potential analogus to Newtonian potential as an example of ``minimally curved spacetime''. We also consider a radially symmetric analogue of the Rindler spacetime of uniform proper acceleration relative to infinity.
Grand Canonical Ensembles in General Relativity
International Nuclear Information System (INIS)
Klein, David; Yang, Wei-Shih
2012-01-01
We develop a formalism for general relativistic, grand canonical ensembles in space-times with timelike Killing fields. Using that, we derive ideal gas laws, and show how they depend on the geometry of the particular space-times. A systematic method for calculating Newtonian limits is given for a class of these space-times, which is illustrated for Kerr space-time. In addition, we prove uniqueness of the infinite volume Gibbs measure, and absence of phase transitions for a class of interaction potentials in anti-de Sitter space.
On hypermomentum in general relativity. Pt.1
International Nuclear Information System (INIS)
Hehl, F.W.; Kerlick, G.D.; Heyde, P. von der
1976-01-01
In this series of notes, we introduce a new quantity into the theory of classical matter fields. Besides the usual energy-momentum tensor, we postulate the existence of a further dynamical attribute of matter, the 3rd rank tensor Δsup(ijk) of hypermomentum. Subsequently, a general relativistic field theory of energy-momentum and hypermomentum is outlined. In Part I we motivate the need for hypermomentum. We split it into spin angular momentum, the dilatation hypermomentum, and traceless proper hypermomentum and discuss their physical meanings and conservation laws. (orig.) [de
Tobacco addiction in the psychiatric population and in the general population
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Renata Marques de Oliveira
2017-12-01
Full Text Available ABSTRACT Objective: To estimate the degree of tobacco addiction and identify independently associated factors by comparing the psychiatric population of secondary and tertiary care with the general population of the primary healthcare network. Method: This is a cross-sectional epidemiological study, conducted in a municipality of São Paulo, with 134 smokers of a Mental Health Outpatient Unit (MHOU, a Psychiatric Hospital (PH, and a Primary Healthcare Unit (PHU. Data were collected by means of individual interviews, recorded on a mobile device. Data were statistically processed using Stata/12 Results: Of the 134 participants, 54.5% were women. While 49.1% of the psychiatric population (MHOU/PH had medium/high nicotine addiction, 58.3% of smokers of the general population had very low/low dependency. The Poisson regression model indicated a higher prevalence of smokers with high dependence among men (PR = 1.41, people aged 49 years or less (15 - 29 years, PR = 4.06, 30 - 39 PR = 2.96 years, 40 - 49 years PR = 1.84, with severe mental disorders (PR = 3.05, with anxiety disorders/other (PR = 3.98, and with high suicide risk (PR = 1.55. Conclusion: Nicotine dependence was greater in the psychiatric population than in the general population. The independent factors associated with severe dependence were sex, age group, diagnosis, and current risk of suicide. These results trigger reflection among nurses on the need to focus more attention on a neglected subject in mental health services.
DEFF Research Database (Denmark)
Håkansson, Kåre; von Buchwald, Christian; Thomsen, Simon F
2011-01-01
The cause of nonallergic rhinitis (NAR) and its relation to lower airway disease remains unclear. The purpose of this study was to perform a descriptive analysis of the occurrence of rhinitis in a Danish general population with focus on NAR and its association with smoking and lower airway disease....
Alcohol consumption and risk of aging macula disorder in a general population: the Rotterdam Study
Boekhoorn, Sharmila S.; Vingerling, Johannes R.; Hofman, Albert; de Jong, Paulus T. V. M.
2008-01-01
To investigate the possible relationship between overall or specific alcohol consumption and risk of aging macula disorder (AMD), a synonym for age-related macular degeneration, in a general population. Alcohol consumption and risk of early or late incident AMD (iAMD) were examined among all
Singularities in the general theory of relativity
International Nuclear Information System (INIS)
Treder, H.J.
1980-01-01
'Regular solutions of Einstein's equations' mean very different things. In the case of the empty-space equations, Rsub(ik) = o, such solutions must be metrics gsub(ik)(xsup(l)) without additionaly singular 'field sources' (Einstein's 'Particle problem'). However the 'phenomenological matter' is defined by the Einstein equations Rsub(ik) - 1/2gsub(ik)R = -kappaTsub(ik) itselves. Therefore if 10 regular functions gsub(ik)(xsup(l)) are given (which the inequalities of Lorentz-signature fulfil) then these gsub(ik) define 10 functions Tsub(ik)(xsup(l)) without singularities. But, the matter-tensor Tsub(ik) must fulfil the two inequalities T >= o, T 0 0 >= 1/2 T only and therefore the Einstein-equations with 'phenomenological matter' mean the two inequalities R >= o, R 0 0 <= o which are incompatible with a permanently regular metric with Lorentz-signature, generally. (author)
Matroidal Structure of Generalized Rough Sets Based on Tolerance Relations
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Hui Li
2014-01-01
of the generalized rough set based on the tolerance relation. The matroid can also induce a new relation. We investigate the connection between the original tolerance relation and the induced relation.
Recommended vitamin D levels in the general population.
Varsavsky, Mariela; Rozas Moreno, Pedro; Becerra Fernández, Antonio; Luque Fernández, Inés; Quesada Gómez, José Manuel; Ávila Rubio, Verónica; García Martín, Antonia; Cortés Berdonces, María; Naf Cortés, Silvia; Romero Muñoz, Manuel; Reyes García, Rebeca; Jódar Gimeno, Esteban; Muñoz Torres, Manuel
2017-03-01
To provide recommendations based on evidence on the management of vitaminD deficiency in the general population. Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology. Recommendations were formulated using the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed) using the term VitaminD and the name of each issue. Papers in English and Spanish with publication date before 17 March 2016 were included. Recommendations were jointly discussed by the Working Group. This document summarizes the data about vitaminD deficiency in terms of prevalence, etiology, screening indications, adequate levels and effects of supplementation on bone and non-skeletal health outcomes. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.
Benzodiazepine use in general population, the municipality of Berane, Montenegro
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Šoškić Miomir
2016-01-01
Full Text Available Background: Benzodiazepines can be classified as one of the most frequently prescribed categories of medication. This medication category is distinguished by a high risk of tolerance and dependence, in the case of long-term, excessive use. Aim: The aim of our study was to analyse the use of benzodiazepines in the general population, municipality of Berane, Montenegro, during the previous year. Methods: Research was based on the analysis of 1000 prescriptions of benzodiazepines, issued by physicians in Primary Health Care. The diagnostic manual utilised for the purpose of this research was International Classification of Diseases (ICD-10. The survey was conducted for a period of 40 days during January and February 2015. Results: The study was performed in the general population, age from 18 to 98 years (621 females and 379 males. The average age of all participants in the study was 64.1±13.1 years. Analysis of data confirmed that the most frequently prescribed from the group of benzodiazepines were: diazepam (42.2%, bromazepam (30.3%, lorazepam (16.4%, alprazolam (6.4%, nitrazepam (2.6% and clonazepam (2.1%. The significant statistical difference (x2=58.664; p<0.001 was found between female patients who used benzodiazepines in 62.1% of cases, compared to male patients who used benzodiazepines in 37.9% of cases. It was confirmed that benzodiazepines were usually prescribed for 17 different diagnoses, mostly for diagnoses from the group I, viz. cluster-diseases of the circulatory system (39.7%, group F-mental and behavioural disorders (31.1% and group E-endocrine, nutritional and metabolic diseases (7.7%. Conclusion: Studies about drug utilisation provide plenty of useful information which can be further used with the aim of achieving more rational prescribing and more effective patient treating.
Validity of the Malaise Inventory in general population samples.
Rodgers, B; Pickles, A; Power, C; Collishaw, S; Maughan, B
1999-06-01
The Malaise Inventory is a commonly used self-completion scale for assessing psychiatric morbidity. There is some evidence that it may represent two separate psychological and somatic subscales rather than a single underlying factor of distress. This paper provides further information on the factor structure of the Inventory and on the reliability and validity of the total scale and two sub-scales. Two general population samples completed the full Inventory: over 11,000 subjects from the National Child Development Study at ages 23 and 33, and 544 mothers of adolescents included in the Isle of Wight epidemiological surveys. The internal consistency of the full 24-item scale and the 15-item psychological subscale were found to be acceptable, but the eight-item somatic sub-scale was less reliable. Factor analysis of all 24 items identified a first main general factor and a second more purely psychological factor. Receiver operating characteristic (ROC) analysis indicated that the validity of the scale held for men and women separately and for different socio-economic groups, by reference to external criteria covering current or recent psychiatric morbidity and service use, and that the psychological sub-scale had no greater validity than the full scale. This study did not support the separate scoring of a somatic sub-scale of the Malaise Inventory. Use of the 15-item psychological sub-scale can be justified on the grounds of reduced time and cost for completion, with little loss of reliability or validity, but this approach would not significantly enhance the properties of the Inventory by comparison with the full 24-item scale. Inclusion of somatic items may be more problematic when the full scale is used to compare particular sub-populations with different propensities for physical morbidity, such as different age groups, and in these circumstances it would be a sensible precaution to utilise the 15-item psychological sub-scale.
Theory of mind and hypomanic traits in general population.
Terrien, Sarah; Stefaniak, Nicolas; Blondel, Marine; Mouras, Harold; Morvan, Yannick; Besche-Richard, Chrystel
2014-03-30
Theory of Mind (ToM) is the ability to assign a set of mental states to yourself and others. In bipolar disorders, alteration of social relationship can be explained by the impairment of the functioning of ToM. Deficit in ToM could be a trait marker of bipolar disorder and people in the general population with high hypomanic personality scores would be more likely to develop bipolar disorders. This study examined 298 participants. Measures of hypomanic personality were evaluated using the Hypomanic Personality Scale. ToM was explored using the Yoni task. Participants also completed the BDI-II. Forward multiple regressions were performed to examine the effect of components of the HPS on the total score in the ToM task. In the women's group, no subscales of the HPS were included in the model. Conversely, the analyses performed on men revealed that the mood vitality and excitement subscale was a significant predictor of ToM abilities. Our study is the first to show the impact of certain dimensions of hypomanic personality on performance in ToM in a male sample. This result supports the idea that deficits in ToM can be a trait marker of bipolar disorder in a healthy male population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
The value of a college degree for foster care alumni: comparisons with general population samples.
Salazar, Amy M
2013-04-01
Higher education is associated with substantial adult life benefits, including higher income and improved quality of life, among others. The current study compared adult outcomes of 250 foster care alumni college graduates with two samples of general population graduates to explore the role higher education plays in these young adults' lives. Outcomes compared include employment, income, housing, public assistance, physical and mental health, happiness, and other outcomes that are often found to be related to educational attainment. Foster care alumni college graduates were very similar to general population college graduates for individual income and rate of employment. However, foster care alumni graduates were behind general population graduates on factors such as self-reported job security, household earnings, health, mental health, financial satisfaction, home ownership, happiness, and public assistance usage. Results have implications for policy and practice regarding the most effective means of supporting postcollege stability of youths with foster care experience.
Insomnia and hypnotic use in Campo Grande general population, Brazil
Directory of Open Access Journals (Sweden)
Souza José Carlos
2002-01-01
Full Text Available The insomnia prevalence in general population was determined by means of 408 home interviews of adults, in a representative sample of Campo Grande city, Brazil. The random sample was stratified by sex, age and economic social status. Insomnia subtypes evaluated were the disorders of sleep initiation (DSI, sleep maintenance (DSM and early awakening (DEA. A structured questionnaire was used with the consent from the interviewed subjects. Statistics used chi-square, and Fisher tests; and inferences based on binomial distribution parameters; the significance level was 5% and confidence interval (CI was 95%.The general prevalence of insomnia was 19.1% (sd=2.0%, mostly women (p=0.0015, and people of less years of schooling (p=0.0317, subtype DSI (14.2%, p=0.0043, and chronic (p=0.7022. Hypnotic drugs were used by 6.9%(sd=1.3% in the last month. Use in the last 2 years, 70.3% mostly insomniacs (p<0.0001, women (p=0.0372 and people over 30 years of age (p=0.0536.
Access to general health care services by a New Zealand population with serious mental illness.
Directory of Open Access Journals (Sweden)
Wheeler A
2014-03-01
Full Text Available INTRODUCTION: Literature suggests that good quality health care access can have a positive impact on the health of people with serious mental illness (SMI, but literature relating to patterns of access by this group is equivocal. AIM: This study was designed to explore health care access patterns in a group of people with SMI and to compare them with a general New Zealand population group, in order for health providers to understand how they might contribute to positive health outcomes for this group. METHODS: The study surveyed 404 mental health consumers aged 18-65 years receiving care from one district health board in Auckland about their patterns of health care access. Results were compared with those from the New Zealand Health Survey of the general population. RESULTS: Findings suggest that the SMI consumer respondents had poorer physical health than the general population respondents, accessed health care services in more complex ways and were more particular about who they accessed for their care than the general population respondents. There was some concern from SMI consumers around discrimination from health care providers. The study also suggested that some proactive management with SMI consumers for conditions such as metabolic syndrome was occurring within the health care community. DISCUSSION: The first point of access for SMI consumers with general health problems is not always the family general practitioner and so other health professionals may sometimes need to consider the mental and physical health of such consumers in a wider context than their own specialism.
Large-scale tides in general relativity
Energy Technology Data Exchange (ETDEWEB)
Ip, Hiu Yan; Schmidt, Fabian, E-mail: iphys@mpa-garching.mpg.de, E-mail: fabians@mpa-garching.mpg.de [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)
2017-02-01
Density perturbations in cosmology, i.e. spherically symmetric adiabatic perturbations of a Friedmann-Lemaȋtre-Robertson-Walker (FLRW) spacetime, are locally exactly equivalent to a different FLRW solution, as long as their wavelength is much larger than the sound horizon of all fluid components. This fact is known as the 'separate universe' paradigm. However, no such relation is known for anisotropic adiabatic perturbations, which correspond to an FLRW spacetime with large-scale tidal fields. Here, we provide a closed, fully relativistic set of evolutionary equations for the nonlinear evolution of such modes, based on the conformal Fermi (CFC) frame. We show explicitly that the tidal effects are encoded by the Weyl tensor, and are hence entirely different from an anisotropic Bianchi I spacetime, where the anisotropy is sourced by the Ricci tensor. In order to close the system, certain higher derivative terms have to be dropped. We show that this approximation is equivalent to the local tidal approximation of Hui and Bertschinger [1]. We also show that this very simple set of equations matches the exact evolution of the density field at second order, but fails at third and higher order. This provides a useful, easy-to-use framework for computing the fully relativistic growth of structure at second order.
Burnout in the working population: relations to psychosocial work factors.
Lindblom, Karin M; Linton, Steven J; Fedeli, Cecilia; Bryngelsson, Ing-Liss
2006-01-01
This study investigated levels of burnout in the general population irrespective of occupation and relations between burnout and psychosocial work factors. A cross-sectional survey featuring sleep problems, psychological distress, burnout (Maslach Burnout Inventory-General Survey), and psychosocial factors at work, was mailed to a random sample of 3,000 participants, aged 20-60. Response rate was 61%. A high level (18%), a low level (19%), and an intermediate group (63%) for burnout were constructed. The high level group was associated with those who were > 50 years old, women, those experiencing psychological distress, and those with a poor psychosocial work climate. The analyses on variables significant in previous analyses showed that the high level group was strongly related to high demands, low control, lack of social support, and disagreeing about values at the workplace even when accounting for age, gender, and psychological distress. We conclude that psychosocial work factors are important in association to burnout regardless of occupation.
Determinants related to gender differences in general practice utilization
DEFF Research Database (Denmark)
Jørgensen, Jeanette Therming; Andersen, John Sahl; Tjønneland, Anne
2016-01-01
OBJECTIVE: This study aims to describe the determinants related to gender differences in the GP utilization in Danish population aged 50-65 years. DESIGN: Cohort-based cross-sectional study. SETTING: Danish general practice. SUBJECTS: Totally, 54,849 participants of the Danish Diet, Cancer...... information on lifestyle (smoking, body mass index (BMI), alcohol use, physical activity), medical conditions (somatic and mental), employment, education, gravidity, and hormone therapy (HT) use was collected by questionnaire. RESULTS: Women had on average 4.1 and men 2.8 consultations per year. In a crude....... Strongest determinants for GP use among Danish adults aged 50-65 years were the presence of medical conditions (somatic and mental) and unemployment, while lifestyle factors (e.g., body mass index, alcohol consumption and smoking) had minor effect....
BOOK REVIEW: Advanced Mechanics and General Relativity Advanced Mechanics and General Relativity
Louko, Jorma
2011-04-01
Joel Franklin's textbook `Advanced Mechanics and General Relativity' comprises two partially overlapping, partially complementary introductory paths into general relativity at advanced undergraduate level. Path I starts with the Lagrangian and Hamiltonian formulations of Newtonian point particle motion, emphasising the action principle and the connection between symmetries and conservation laws. The concepts are then adapted to point particle motion in Minkowski space, introducing Lorentz transformations as symmetries of the action. There follows a focused development of tensor calculus, parallel transport and curvature, using examples from Newtonian mechanics and special relativity, culminating in the field equations of general relativity. The Schwarzschild solution is analysed, including a detailed discussion of the tidal forces on a radially infalling observer. Basics of gravitational radiation are examined, highlighting the similarities to and differences from electromagnetic radiation. The final topics in Path I are equatorial geodesics in Kerr and the motion of a relativistic string in Minkowski space. Path II starts by introducing scalar field theory on Minkowski space as a limit of point masses connected by springs, emphasising the action principle, conservation laws and the energy-momentum tensor. The action principle for electromagnetism is introduced, and the coupling of electromagnetism to a complex scalar field is developed in a detailed and pedagogical fashion. A free symmetric second-rank tensor field on Minkowski space is introduced, and the action principle of general relativity is recovered from coupling the second-rank tensor to its own energy-momentum tensor. Path II then merges with Path I and, supplanted with judicious early selections from Path I, can proceed to the Schwarzschild solution. The choice of material in each path is logical and focused. A notable example in Path I is that Lorentz transformations in Minkowki space are introduced
Child maltreatment in Germany: prevalence rates in the general population.
Witt, Andreas; Brown, Rebecca C; Plener, Paul L; Brähler, Elmar; Fegert, Jörg M
2017-01-01
Child maltreatment and its consequences are considered a major public health problem. So far, there is only one study from Germany reporting prevalence rates on different types of maltreatment. A representative sample of the German general population was examined for experiences of child maltreatment using the Childhood Trauma Questionnaire (CTQ) between September and November 2016. A total of 2510 (53.3% female) participants between 14 and 94 years (M = 48.8 years) were enrolled. Besides the CTQ, a range of sociodemographic information was collected. The interrelatedness of different types of maltreatment was examined using configuration analysis and predictors for maltreatment were identified by performing binary logistic regression analyses. Overall, 2.6% (f: 3.9%, m: 1.2%) of all participants reported severe emotional abuse, 3.3% (f: 3.4%, m: 3.3%) severe physical abuse, 2.3% (f: 3.7%, m: 0.7%) severe sexual abuse, 7.1% (f: 8.1%, m: 5.9%) severe emotional neglect and 9% (f: 9.2%, m: 8.9%) severe physical neglect. Women were more likely to report at least moderate sexual and emotional abuse than men. The largest difference between age groups was reported for physical neglect, with participants aged over 70 years reporting the highest rates. Participants who reported childhood maltreatment were more likely to be unemployed or have lower educational outcomes. The most common combination of maltreatment types were physical and emotional neglect, all five types of maltreatment combined and physical and emotional neglect and physical abuse combined. Child maltreatment, especially physical neglect is common in the German population. Women seem to be at greater risk for sexual and emotional abuse than men. Knowledge about different types of maltreatment based on the Childhood Trauma Questionnaire (CTQ) can help to put findings of future studies into an epidemiological and societal context.
Martín-Santiago, Oscar; Suazo, Vanessa; Rodríguez-Lorenzana, Alberto; Ruiz de Azúa, Sonia; Valcárcel, César; Díez, Álvaro; Grau, Adriana; Domínguez, Cristina; Gallardo, Ricardo; Molina, Vicente
2016-01-01
Subclinical psychotic symptoms are associated to negative life outcomes in the general population, but their relationship with cognitive performance is still not well understood. Assessing the relationship between performance in cognitive domains and subclinical psychotic symptoms in the general population may also help understand the handicap attributed to clinical psychosis, in which these alterations are present. Subclinical and cognitive assessments were obtained in 203 participants from the general population by means of the Community Assessment of Psychic Experiences, the Brief Assessment of Cognition in Schizophrenia, the Wechsler Adults Intelligence Scale and the Wisconsin Card Sorting Test. The positive and negative subclinical symptoms and their relationship with age and cognition were examined, followed by assessing the influence of subclinical depression scores on the possible relationships between those subclinical psychotic symptoms and cognitive deficits. Inverse relationships were found between frequency in the Community Assessment of Psychic Experiences positive dimension and motor speed, and frequency and distress in the Community Assessment of Psychic Experiences negative dimension and motor speed. A direct relationship was also found between distress scores of the positive dimension and executive functions. Both positive and negative subclinical symptoms were related to depression scores. Psychotic symptoms, similar to those in the clinical population, may be associated with cognitive deficits in the general population. Copyright © 2015 SEP y SEPB. Published by Elsevier España. All rights reserved.
Life Expectancy in Police Officers: A Comparison with the U.S. General Population
Violanti, John M.; Hartley, Tara A.; Gu, Ja K.; Fekedulegn, Desta; Andrew, Michael E.; Burchfiel, Cecil M.
2016-01-01
Previous epidemiological research indicates that police officers have an elevated risk of death relative to the general population overall and for several specific causes. Despite the increased risk for mortality found in previous research, controversy still exists over the life expectancy of police officers. The goal of the present study was to compare life expectancy of male police officers from Buffalo New York with the U.S. general male population utilizing an abridged life table method. On average, the life expectancy of Buffalo police officers in our sample was significantly lower than the U.S. population (mean difference in life expectancy =21.9 years; 95% CI: 14.5-29.3; ppolice officers was shorter and differences were more pronounced in younger age categories. Additionally, police officers had a significantly higher average probability of death than did males in the general population (mean difference= 0.40; 95% CI: 0.26,-0.54; ppolice officers was 21 times larger than that of the general population (Buffalo male officers vs. U.S. males = 21.7, 95% CI: 5.8-37.7). Possible reasons for shorter life expectancy among police are discussed, including stress, shift work, obesity, and hazardous environmental work exposures. PMID:24707585
Profile of mortality from external causes among Seventh-day Adventists and the general populations.
Velten, Ana Paula Costa; Cade, Nágela Valadão; Silva, Gulnar Azevedo E; Oliveira, Elizabete Regina Araújo de
2017-07-01
This paper aimed to compare the profile of mortality from external causes among Seventh-day Adventists and the general population of Espírito Santo from 2003 to 2009. A search of Adventists was performed in the nominal database of the Mortality Information System containing data on Adventists provided by the administrative offices of the institution. Deaths from external causes occurred during the study period were then divided into two groups: Adventists and the general population. Adventists had lower proportional mortality from external causes (10%) than the general population (19%), and males were the main reason for this difference. In both groups, deaths prevailed in the 20-29 years age group. Deaths from accidental causes were most significant among Adventists (68.08%), while deaths from intentional causes related to assault and self-inflicted injuries were more significant in the general population (53.67% of all deaths). The standardized mortality ratio for external causes was 41.3, thus, being Adventist reduced mortality by 58.7%. It is believed that the benefit of Adventists observed for mortality from external causes is related to this group's abstinence from alcohol consumption.
General and special education teachers' relations within teamwork ...
African Journals Online (AJOL)
and instruction, assessment and evaluation, and classroom management and behavior. Typically, the ... teaching techniques and learning processes. ... general objective of this research is to establish the relations of general and special.
Napping and associated factors: a Japanese nationwide general population survey.
Furihata, Ryuji; Kaneita, Yoshitaka; Jike, Maki; Ohida, Takashi; Uchiyama, Makoto
2016-04-01
The objective of this study was to investigate napping habits and their associated factors in the Japanese adult general population. The cross-sectional survey was conducted in November 2007 for subjects selected randomly from among 300 districts throughout Japan. Data from 7664 people (3527 men and 4137 women), aged 20-99 years, were analyzed. Participants completed a self-administered questionnaire on frequency and duration of napping. The percentage of responders for high-frequency napping, four or more days per week, was 21.2% among men and 17.1% among women. The percentage of responders for long-duration napping, 2 h or more per one nap, was 2.9% among men and 2.6% among women. Multivariate logistic regression analyses revealed that men, older age, smoking, insomnia symptoms, long sleep duration, excessive daytime sleepiness, and having sufficient rest obtained by sleep were positively associated with high-frequency napping, whereas alcohol drinking showed a negative association. Older age was negatively associated with long-duration napping whereas living in a large community, smoking, long sleep duration, excessive daytime sleepiness, and psychological stress showed a positive association. These findings provide important data for future studies aimed at improvement of sleep habits. Copyright © 2016 Elsevier B.V. All rights reserved.
Epidemiology of Hepatitis C Virus in Bangladeshi General Population
Directory of Open Access Journals (Sweden)
Mamun Al-Mahtab
2009-11-01
Full Text Available Background: Hepatitis C virus is encountered sporadically in Bangladesh. It results in a wide range liver diseases, with asymptomatic acute hepatitis rarely at one end to HCC at the other end of the spectrum. Methods: 1018 individuals of different age groups and sex with varied religious, educational and social backgrounds were tested for anti-HCV by ELISA. Before testing, blood samples were preserved at -20°C. The study was conducted in a semi-urban location on the outskirts of Dhaka. Results: 0.88% tested positive for anti HCV. None of them tested positive for HBsAg. There was a male predominance and those who tested positive were mostly between 17 and 50 years of age. Major risk factors for exposure to HBV appeared to be injudicious use of injectable medications, treatment by unqualified, traditional practitioners, mass-vaccination against cholera and smallpox, barbers and body piercing. Conclusion: HCV remains an important cause of morbidity and mortality in Bangladesh. Key words: HCV; prevalence; general population; Bangladesh.DOI: 10.3329/bsmmuj.v2i1.3705 BSMMU J 2009; 2(1: 14-17
Association between Impulsivity and Weight Status in a General Population
Directory of Open Access Journals (Sweden)
Marc Bénard
2017-03-01
Full Text Available The objective of this study is to examine the association between impulsivity and weight status in a large sample of the adult general population in France, and the influence of gender on this relationship. A total of 11,929 men and 39,114 women participating in the NutriNet-Santé cohort were selected in this cross-sectional analysis. The Barratt Impulsiveness Scale (BIS-11 was used to assess impulsivity. Weight and height were self-reported. The association between impulsivity and BMI was estimated using logistic regressions adjusted for socio-demographic and lifestyle factors. Individuals with high impulsivity levels (BIS-11 total score >71 were more likely to be obese (Odds Ratio (OR = 1.80, 95% Confidence Interval (CI: 1.39, 2.33 in men; OR = 1.30, 95% CI: 1.15, 1.48 in women compared to individuals in the average range of impulsivity. The strongest associations between impulsivity and obesity were observed in men, where highly impulsive participants were more likely to be class III obese (BMI > 40 kg/m2 (OR = 3.57, 95% CI: 1.86, 6.85. This large sample analysis supports the existence of a relationship between impulsivity and weight status and the importance of psychological factors in the prevention of obesity.
Association between Impulsivity and Weight Status in a General Population.
Bénard, Marc; Camilleri, Géraldine M; Etilé, Fabrice; Méjean, Caroline; Bellisle, France; Reach, Gérard; Hercberg, Serge; Péneau, Sandrine
2017-03-01
The objective of this study is to examine the association between impulsivity and weight status in a large sample of the adult general population in France, and the influence of gender on this relationship. A total of 11,929 men and 39,114 women participating in the NutriNet-Santé cohort were selected in this cross-sectional analysis. The Barratt Impulsiveness Scale (BIS-11) was used to assess impulsivity. Weight and height were self-reported. The association between impulsivity and BMI was estimated using logistic regressions adjusted for socio-demographic and lifestyle factors. Individuals with high impulsivity levels (BIS-11 total score >71) were more likely to be obese (Odds Ratio (OR) = 1.80, 95% Confidence Interval (CI): 1.39, 2.33 in men; OR = 1.30, 95% CI: 1.15, 1.48 in women) compared to individuals in the average range of impulsivity. The strongest associations between impulsivity and obesity were observed in men, where highly impulsive participants were more likely to be class III obese (BMI > 40 kg/m²) (OR = 3.57, 95% CI: 1.86, 6.85). This large sample analysis supports the existence of a relationship between impulsivity and weight status and the importance of psychological factors in the prevention of obesity.
DSR Theories, Conformal Group and Generalized Commutation Relation
International Nuclear Information System (INIS)
Leiva, Carlos
2006-01-01
In this paper the relationship of DSR theories and Conformal Group is reviewed. On the other hand, the relation between DSR Magueijo Smolin generators and generalized commutation relations is also shown
Generalized uncertainty relations and characteristic invariants for the multimode states
International Nuclear Information System (INIS)
Sudarshan, E.C.G.; Chiu, C.B.; Bhamathi, G.
1995-01-01
The close relationship between the zero-point energy, the uncertainty relation, coherent states, squeezed states, and correlated states for one mode is investigated. This group theoretic perspective of the problem enables the parametrization and identification of their multimode generalization. A simple and efficient method of determining the canonical structure of the generalized correlated states is presented. Implication of canonical commutation relations for correlations are not exhausted by the Heisenberg uncertainty relation, not even by the Schroedinger-Robertson uncertainty inequality, but there are relations in the multimode case that are the generalization of the Schroedinger-Robertson relation
The prevalence and morbidity of sensitization to fragrance mix I in the general population
DEFF Research Database (Denmark)
Thyssen, J P; Linneberg, A; Menné, T
2009-01-01
BACKGROUND: The prevalence of sensitization to fragrance mix (FM) I and Myroxylon pereirae (MP, balsam of Peru) has decreased in recent years among Danish women with dermatitis. OBJECTIVES: This study investigated whether the decrease could be confirmed among women in the general population. Furt...... supported a recent decrease in the prevalence of FM I and MP sensitization in Denmark. The study also showed that fragrance sensitization was associated with self-reported cosmetic dermatitis and use of health care related to cosmetic dermatitis....
Serum chemerin levels are inversely associated with renal function in a general population
DEFF Research Database (Denmark)
Zylla, Stephanie; Rettig, Rainer; Völzke, Henry
2018-01-01
OBJECTIVE: Chemerin has been found to be highly expressed in the kidneys of rodents and has been suggested to affect metabolic syndrome (MetS)-related phenotypes which are in turn related to kidney damage. Only few clinical studies have addressed the relation between circulating chemerin and renal...... function in humans, and no population-based analyses have yet been performed. The potential influence of MetS-related phenotypes on the assumed association has been largely neglected. We aimed to investigate the association of serum chemerin with renal function in a general population with special regard......GFR and revealed that each increase in chemerin per 25 ng/mL was associated with an about threefold higher odds of chronic kidney disease [odds ratio 2.72 (95% confidence interval 2.26-3.29)]. CONCLUSIONS: Our results demonstrate a strong inverse association between serum chemerin levels and renal function...
Yaffe, Beril; Walder, Deborah J
2016-05-30
Attentional-interference using emotional Stroop tasks (ESTs) is greater among individuals in the general population with positive (versus negative) schizotypal traits; specifically in response to negatively (versus positively) valenced words, potentially capturing threat-sensitivity. Variability in attentional-interference as a function of subcategories of negatively valenced words (and in relation to schizotypal traits) remains underexplored in EST studies. We examined attentional-interference across negative word subcategories (fear/anger/sadness/disgust), and in relation to positive schizotypy, among non-clinical individuals in the general population reporting varying degrees of schizotypal traits. As hypothesized, performance differed across word subcategories, though the pattern varied from expectation. Attentional-interference was greater for fear and sadness compared to anger; and analogous for fear, disgust, and sadness. In the high schizotypy group, positive schizotypal traits were directly associated with attentional-interference to disgust. Attentional-interference was comparable between high- and low-positive schizotypy. Results suggest negative emotion subcategories may differentially reflect threat-sensitivity. Disgust-sensitivity may be particularly salient in (non-clinical) positive schizotypy. Findings have implications for understanding negative emotion specificity and variability in stimulus presentation modality when studying threat-related attentional-interference. Finally, disgust-related attentional-interference may serve as a cognitive correlate of (non-clinical) positive schizotypy. Expanding this research to prodromal populations will help explore disgust-related attentional-interference as a potential cognitive marker of positive symptoms. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Kroon, Jojanneke S.; Wohlfarth, Tamar D.; Dieleman, Jeanne; Sutterland, Arjen L.; Storosum, Jitschak G.; Denys, Damiaan; de Haan, Lieuwe; Sturkenboom, Mirjam C. J. M.
2013-01-01
To estimate the incidence rates (IRs) of bipolar I and bipolar II disorders in the general population according to sociodemographic population characteristics. A cohort study (during the years 1996-2007) was conducted in a general practitioners research database with a longitudinal electronic record
A Structure for Population Education: Goals, Generalizations, and Behavioral Objectives.
Lane, Mary Turner; Wileman, Ralph E.
This book is written to assist anyone who wants to learn about, teach, or plan curricula for population education. A structure is provided that educators can use for first graders or for high school students. Chapter 1 identifies the population phenomenon and the need to study it. Chapter 2 gives the elements of the structure: goals,…
Does probability of occurrence relate to population dynamics?
Thuiller, Wilfried; Münkemüller, Tamara; Schiffers, Katja H; Georges, Damien; Dullinger, Stefan; Eckhart, Vincent M; Edwards, Thomas C; Gravel, Dominique; Kunstler, Georges; Merow, Cory; Moore, Kara; Piedallu, Christian; Vissault, Steve; Zimmermann, Niklaus E; Zurell, Damaris; Schurr, Frank M
2014-12-01
Hutchinson defined species' realized niche as the set of environmental conditions in which populations can persist in the presence of competitors. In terms of demography, the realized niche corresponds to the environments where the intrinsic growth rate ( r ) of populations is positive. Observed species occurrences should reflect the realized niche when additional processes like dispersal and local extinction lags do not have overwhelming effects. Despite the foundational nature of these ideas, quantitative assessments of the relationship between range-wide demographic performance and occurrence probability have not been made. This assessment is needed both to improve our conceptual understanding of species' niches and ranges and to develop reliable mechanistic models of species geographic distributions that incorporate demography and species interactions. The objective of this study is to analyse how demographic parameters (intrinsic growth rate r and carrying capacity K ) and population density ( N ) relate to occurrence probability ( P occ ). We hypothesized that these relationships vary with species' competitive ability. Demographic parameters, density, and occurrence probability were estimated for 108 tree species from four temperate forest inventory surveys (Québec, Western US, France and Switzerland). We used published information of shade tolerance as indicators of light competition strategy, assuming that high tolerance denotes high competitive capacity in stable forest environments. Interestingly, relationships between demographic parameters and occurrence probability did not vary substantially across degrees of shade tolerance and regions. Although they were influenced by the uncertainty in the estimation of the demographic parameters, we found that r was generally negatively correlated with P occ , while N, and for most regions K, was generally positively correlated with P occ . Thus, in temperate forest trees the regions of highest occurrence
Does probability of occurrence relate to population dynamics?
Thuiller, Wilfried; Münkemüller, Tamara; Schiffers, Katja H.; Georges, Damien; Dullinger, Stefan; Eckhart, Vincent M.; Edwards, Thomas C.; Gravel, Dominique; Kunstler, Georges; Merow, Cory; Moore, Kara; Piedallu, Christian; Vissault, Steve; Zimmermann, Niklaus E.; Zurell, Damaris; Schurr, Frank M.
2014-01-01
Hutchinson defined species' realized niche as the set of environmental conditions in which populations can persist in the presence of competitors. In terms of demography, the realized niche corresponds to the environments where the intrinsic growth rate (r) of populations is positive. Observed species occurrences should reflect the realized niche when additional processes like dispersal and local extinction lags do not have overwhelming effects. Despite the foundational nature of these ideas, quantitative assessments of the relationship between range-wide demographic performance and occurrence probability have not been made. This assessment is needed both to improve our conceptual understanding of species' niches and ranges and to develop reliable mechanistic models of species geographic distributions that incorporate demography and species interactions.The objective of this study is to analyse how demographic parameters (intrinsic growth rate r and carrying capacity K ) and population density (N ) relate to occurrence probability (Pocc ). We hypothesized that these relationships vary with species' competitive ability. Demographic parameters, density, and occurrence probability were estimated for 108 tree species from four temperate forest inventory surveys (Québec, western USA, France and Switzerland). We used published information of shade tolerance as indicators of light competition strategy, assuming that high tolerance denotes high competitive capacity in stable forest environments.Interestingly, relationships between demographic parameters and occurrence probability did not vary substantially across degrees of shade tolerance and regions. Although they were influenced by the uncertainty in the estimation of the demographic parameters, we found that r was generally negatively correlated with Pocc, while N, and for most regions K, was generally positively correlated with Pocc. Thus, in temperate forest trees the regions of highest occurrence
Differential forms and the geometry of general relativity
Dray, Tevian
2015-01-01
Differential Forms and the Geometry of General Relativity provides readers with a coherent path to understanding relativity. Requiring little more than calculus and some linear algebra, it helps readers learn just enough differential geometry to grasp the basics of general relativity.The book contains two intertwined but distinct halves. Designed for advanced undergraduate or beginning graduate students in mathematics or physics, most of the text requires little more than familiarity with calculus and linear algebra. The first half presents an introduction to general relativity that describes
Causes of death in rheumatoid arthritis: How do they compare to the general population?
Widdifield, Jessica; Paterson, J Michael; Huang, Anjie; Bernatsky, Sasha
2018-03-07
To compare mortality rates, underlying causes of death, excess mortality and years of potential life lost (YPLL) among rheumatoid arthritis (RA) patients relative to the general population. We studied an inception cohort of 87,114 Ontario RA patients and 348,456 age/sex/area-matched general population comparators over 2000 to 2013. All-cause, cause-specific, and excess mortality rates, mortality rate ratios (MRRs), and YPLL were estimated. A total of 11,778 (14% of) RA patients and 32,472 (9% of) comparators died during 508,385 and 1,769,365 person-years (PY) of follow-up, respectively, for corresponding mortality rates of 232 (95% CI 228, 236) and 184 (95% CI 182, 186) per 10,000 PYs. Leading causes of death in both groups were diseases of the circulatory system, cancer, and respiratory conditions. Increased mortality for all-cause and specific causes was observed in RA relative to the general population. MRRs were elevated for most causes of death. Age-specific mortality ratios illustrated a high excess mortality among RA patients under 45 years of age for respiratory disease and circulatory disease. RA patients lost 7,436 potential years of life per 10,000 persons, compared with 4,083 YPLL among those without RA. Mortality rates were increased in RA patients relative to the general population across most causes of death. The potential life years lost (before the age of 75) among RA patients was roughly double that among those without RA, reflecting higher rate ratios for most causes of death and RA patients dying at earlier ages. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Tarannum, Fouzia; Prasad, R K Shiva; Shobha, R; Kumar, B B Santosh; Ebenezer, Supriya
2015-01-01
Preterm low birth weight (PTLBW) is a public health issue which needs to be dealt with by educating the general female population. One of the major contributing factors is periodontal disease and treatment of the same could reduce the occurrence of PTLBW babies. Therefore, awareness of this among the female population is highly essential. Hence, this survey was planned with the aim to explore the awareness of the general female population regarding the association of periodontal disease and PTLBW. This survey consisted of nine close-ended questions answered by 1284 females. Younger individuals had higher knowledge scores as compared to the older individuals (r = -0.161) and the more educated group had a higher knowledge score as compared to the less educated groups (r = 0.322). Furthermore, married women seemed to be more aware of the relation of PTLBW to periodontal disease as compared to unmarried women. Younger and educated females had better awareness of the association between periodontal diseases and PTLBW. Hence, efforts to educate the general female population on this association could contribute toward the reduction of the risk of PTLBW.
Constraints on stress-energy perturbations in general relativity
International Nuclear Information System (INIS)
Traschen, J.
1985-01-01
Conditions are found for the existence of integral constraints on stress-energy perturbations in general relativity. The integral constraints can be thought of as a general-relativistic generalization of the conservation of energy and momentum of matter perturbations in special relativity. The constraints are stated in terms of a vector field V, and the Robertson-Walker spacetimes are shown to have such constraint vectors. Although in general V is not a Killing vector, in a vacuum spacetime the constraint vectors are precisely the Killing vectors
Varanka, Dalia; Jiang, Bin; Yao, Xiaobai
2010-01-01
Measures of population pressure, referring in general to the stress upon the environment by human consumption of resources, are imperative for environmental sustainability studies and management. Development based on resource consumption is the predominant factor of population pressure. This paper presents a spatial model of population pressure by linking consumption associated with regional urbanism and ecosystem services. Maps representing relative geographic degree and extent of natural resource consumption and degree and extent of impacts on surrounding areas are new, and this research represents the theoretical research toward this goal. With development, such maps offer a visualization tool for planners of various services, amenities for people, and conservation planning for ecologist. Urbanization is commonly generalized by census numbers or impervious surface area. The potential geographical extent of urbanism encompasses the environmental resources of the surrounding region that sustain cities. This extent is interpolated using kriging of a variable based on population wealth data from the U.S. Census Bureau. When overlayed with land-use/land-cover data, the results indicate that the greatest estimates of population pressure fall within mixed forest areas. Mixed forest areas result from the spread of cedar woods in previously disturbed areas where further disturbance is then suppressed. Low density areas, such as suburbanization and abandoned farmland are characteristic of mixed forest areas.
Martin, Joanna; Hamshere, Marian L; Stergiakouli, Evangelia; O'Donovan, Michael C; Thapar, Anita
2014-10-15
Attention-deficit/hyperactivity disorder (ADHD) can be viewed as the extreme end of traits in the general population. Epidemiological and twin studies suggest that ADHD frequently co-occurs with and shares genetic susceptibility with autism spectrum disorder (ASD) and ASD-related traits. The aims of this study were to determine whether a composite of common molecular genetic variants, previously found to be associated with clinically diagnosed ADHD, predicts ADHD and ASD-related traits in the general population. Polygenic risk scores were calculated in the Avon Longitudinal Study of Parents and Children (ALSPAC) population sample (N = 8229) based on a discovery case-control genome-wide association study of childhood ADHD. Regression analyses were used to assess whether polygenic scores predicted ADHD traits and ASD-related measures (pragmatic language abilities and social cognition) in the ALSPAC sample. Polygenic scores were also compared in boys and girls endorsing any (rating ≥ 1) ADHD item (n = 3623). Polygenic risk for ADHD showed a positive association with ADHD traits (hyperactive-impulsive, p = .0039; inattentive, p = .037). Polygenic risk for ADHD was also negatively associated with pragmatic language abilities (p = .037) but not with social cognition (p = .43). In children with a rating ≥ 1 for ADHD traits, girls had a higher polygenic score than boys (p = .003). These findings provide molecular genetic evidence that risk alleles for the categorical disorder of ADHD influence hyperactive-impulsive and attentional traits in the general population. The results further suggest that common genetic variation that contributes to ADHD diagnosis may also influence ASD-related traits, which at their extreme are a characteristic feature of ASD. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
Joint Hypermobility Classes in 9-Year-Old Children from the General Population and Anxiety Symptoms.
Ezpeleta, Lourdes; Navarro, José Blas; Osa, Núria de la; Penelo, Eva; Bulbena, Antoni
2018-05-25
To obtain joint hypermobility classes in children from the general population and to study their characteristics in relation to anxiety measures. A total of 336 nine-year-old children from the general population were clinically assessed through 9 items of hypermobility, and their parents reported about the severity of anxiety symptoms. Latent class analysis was estimated to group the children according to the presence of hypermobility symptoms, and the obtained classes were related to anxiety. A 2-class solution, labeled as high hypermobility and low hypermobility, best fitted the data. Children in the high hypermobility group scored higher in separation anxiety, social phobia, physical injury fears, and total anxiety than did those in the low group. When applying the threshold reference scores to the total anxiety score, 7.4% of children in the high hypermobility group versus 6% in the low group were reported to experience clinical elevations on total anxiety. High symptoms of hypermobility are associated with higher scores in anxiety symptoms in children from the general population. Children with frequent symptoms of hypermobility may benefit from screening for anxiety symptoms because a subset of them are experiencing clinical elevations and may need comprehensive physical and psychological treatment.
Kim, Ji-Hyun; Cho, Maeng Je; Hong, Jin Pyo; Bae, Jae Nam; Cho, Seong-Jin; Hahm, Bong-Jin; Lee, Dong-Woo; Park, Jong-Ik; Lee, Jun-Young; Jeon, Hong Jin; Chang, Sung Man
2015-11-01
This study investigated gender differences in symptom profiles of major depressive disorder (MDD) in the Korean general population. Data were pooled from the series of nationwide Korean Epidemiologic Catchment Area surveys conducted in 2001, 2006 and 2011, respectively. Of the 18,807 participants, 507 (397 women and 110 men) were diagnosed with MDD within the prior 12 months. In agreement with previous studies, women with MDD appeared to be more vulnerable to experiencing atypical depressive episodes defined as depression with two or more symptoms of fatigue, increased appetite and hypersomnia (P differences in symptomatology of MDD in the general Korean population, and the results are comparable to previous investigations from western societies. Assumingly, the intercultural similarity in female preponderance to atypical depression might reflect the common biological construct underlying the gender difference in mechanism of MDD. In clinical settings, gender differences of MDD should be carefully considered, because these features could be related with treatment response and drug side effects.
The Prevalence and Typologies of Controlling Behaviors in a General Population Sample.
Walker, Kate; Sleath, Emma; Tramontano, Carlo
2017-10-01
The aim of this study was to examine the prevalence and typologies of controlling behaviors within a general population sample. Participants ( N = 427) completed the Revised Controlling Behaviors Scale and the Revised Conflict Tactics Scale. Prevalence of perpetration and victimization of controlling behaviors was relatively high, although the frequency and severity of the behaviors was mainly low level. Five clusters were established based on the use of five types of controlling behaviors: economic, threatening, intimidating, emotional, and isolating. Significant differences were found between the perpetration clusters and (a) minor physical assault, (b) severe physical assault, (c) minor psychological aggression, and (d) severe psychological aggression. Furthermore, significant differences were found between the victimization clusters and (a) physical assault, (b) minor psychological aggression, and (c) severe psychological aggression. It is clear that controlling behaviors are a feature within general population relationships, and further research is required to understand when such behaviors become problematic, and what needs to be done to prevent this from happening.
6th International Conference on the History of General Relativity
Eisenstaedt, Jean; The Universe of General Relativity; GR 6
2005-01-01
This volume from the Einstein Studies Series is based largely on papers presented at the Sixth International Conference on the History of General Relativity, held in Amsterdam on June 26-29, 2002. These contributions from notable experts offer both new and historical insights on gravitation, general relativity, cosmology, unified field theory, and the history of science. Topics discussed include the prehistory of special relativity, early attempts at a relativistic theory of gravitation, the beginnings of general relativity, the problem of motion in the context of relativity, conservation laws, the axiomatization of relativity, classical and contemporary cosmology, gravitation and electromagnetism, quantum gravity, and relativity as seen through the eyes of the public and renowned relativists. Contributors: K. Brading; G. Gale; H.F.M. Goenner; J. Goldberg; S. Katzir; D. Kennefick; H. Kragh; C. Lehner; U. Majer; J. Mattingly; E.T. Newman; J.D. Norton; J. Renn; R. Rynasiewicz; J.M. Sánchez-Ron; T. Sauer; C. Sm...
Stochastic resonance in a generalized Von Foerster population growth model
Energy Technology Data Exchange (ETDEWEB)
Lumi, N.; Mankin, R. [Institute of Mathematics and Natural Sciences, Tallinn University, 25 Narva Road, 10120 Tallinn (Estonia)
2014-11-12
The stochastic dynamics of a population growth model, similar to the Von Foerster model for human population, is studied. The influence of fluctuating environment on the carrying capacity is modeled as a multiplicative dichotomous noise. It is established that an interplay between nonlinearity and environmental fluctuations can cause single unidirectional discontinuous transitions of the mean population size versus the noise amplitude, i.e., an increase of noise amplitude can induce a jump from a state with a moderate number of individuals to that with a very large number, while by decreasing the noise amplitude an opposite transition cannot be effected. An analytical expression of the mean escape time for such transitions is found. Particularly, it is shown that the mean transition time exhibits a strong minimum at intermediate values of noise correlation time, i.e., the phenomenon of stochastic resonance occurs. Applications of the results in ecology are also discussed.
Antidepressants and gastrointestinal symptoms in the general Dutch adult population
Schurink, B.; Tielemans, M.M.; Aaldering, B.R.; Eikendal, T.; Jaspers Focks, J.; Laheij, R.J.F.; Jansen, J.B.M.J.; Rossum, L.G.M. van; Oijen, M.G.H. van
2014-01-01
BACKGROUND: Gastrointestinal symptoms are frequently reported adverse effects of antidepressants, but antidepressants are also a treatment modality in functional gastrointestinal disorders. We aimed to assess the association between antidepressant use and gastrointestinal symptoms in the general
Diagnostic devices for osteoporosis in the general population
DEFF Research Database (Denmark)
Høiberg, M P; Rubin, Katrine Hass; Hermann, Pernille
2016-01-01
INTRODUCTION: A diagnostic gap exists in the current dual photon X-ray absorptiometry (DXA) based diagnostic approach to osteoporosis. Other diagnostic devices have been developed, but no comprehensive review concerning the applicability of these diagnostic devices for population-based screening...... have been performed. MATERIAL AND METHODS: A systematic review of Embase, Medline and the Cochrane Central Register for Controlled Trials was performed for population-based studies that focused on technical methods that could either indicate bone mineral density (BMD) by DXA, substitute for DXA...
The consistency assessment of topological relations in cartographic generalization
Zheng, Chunyan; Guo, Qingsheng; Du, Xiaochu
2006-10-01
The field of research in the generalization assessment has been less studied than the generalization process itself, and it is very important to keep topological relation consistency for meeting generalization quality. This paper proposes a methodology to assess the quality of generalized map from topological relations consistency. Taking roads (including railway) and residential areas for examples, from the viewpoint of the spatial cognition, some issues about topological consistency in different map scales are analyzed. The statistic information about the inconsistent topological relations can be obtained by comparing the two matrices: one is the matrix for the topological relations in the generalized map; the other is the theoretical matrix for the topological relations that should be maintained after generalization. Based on the fuzzy set theory and the classification of map object types, the consistency evaluation model of topological relations is established. The paper proves the feasibility of the method through the example about how to evaluate the local topological relations between simple roads and residential area finally.
Generalized string theory mapping relations between gravity and gauge theory
International Nuclear Information System (INIS)
Bjerrum-Bohr, N.E.J.
2003-01-01
A previous study of the Kawai, Lewellen and Tye (KLT) relations between gravity and gauge theories, imposed by the relationship of closed and open strings, are here extended in the light of general relativity and Yang-Mills theory as effective field theories. We discuss the possibility of generalizing the traditional KLT mapping in this effective setting. A generalized mapping between the effective Lagrangians of gravity and Yang-Mills theory is presented, and the corresponding operator relations between gauge and gravity theories at the tree level are further explored. From this generalized mapping remarkable diagrammatic relations are found, linking diagrams in gravity and Yang-Mills theory, as well as diagrams in pure effective Yang-Mills theory. Also the possibility of a gravitational coupling to an antisymmetric field in the gravity scattering amplitude is considered, and shown to allow for mixed open-closed string solutions, i.e., closed heterotic strings
Can one tell Einstein's unimodular theory from Einstein's general relativity?
Alvarez, Enrique
2005-01-01
The so called unimodular theory of gravitation is compared with general relativity in the quadratic (Fierz-Pauli) regime, using a quite broad framework, and it is argued that quantum effects allow in principle to discriminate between both theories.
The role of Einstein's general relativity theory in today's physics
International Nuclear Information System (INIS)
Bicak, J.
The relationships are discussed of the general relativity theory to other fields of today's physics. Recent results are reported of studies into gravitational radiation, relativistic astrophysics, cosmology and the quantum theory. (Z.M.)
Generalized hypervirial and Blanchard's recurrence relations for radial matrix elements
International Nuclear Information System (INIS)
Dong Shihai; Chen Changyuan; Lozada-Cassou, M
2005-01-01
Based on the Hamiltonian identity, we propose a generalized expression of the second hypervirial for an arbitrary central potential wavefunction in arbitrary dimensions D. We demonstrate that the new proposed second hypervirial formula is very powerful in deriving the general Blanchard's and Kramers' recurrence relations among the radial matrix elements. As their useful and important applications, we derive all general Blanchard's and Kramers' recurrence relations and some identities for the Coulomb-like potential, harmonic oscillator and Kratzer oscillator. The recurrence relation and identity between the exponential functions and the powers of the radial function are established for the Morse potential. The corresponding general Blanchard's and Kramers' recurrence relations in 2D are also briefly studied
Generalizing Evidence From Randomized Clinical Trials to Target Populations
Cole, Stephen R.; Stuart, Elizabeth A.
2010-01-01
Properly planned and conducted randomized clinical trials remain susceptible to a lack of external validity. The authors illustrate a model-based method to standardize observed trial results to a specified target population using a seminal human immunodeficiency virus (HIV) treatment trial, and they provide Monte Carlo simulation evidence supporting the method. The example trial enrolled 1,156 HIV-infected adult men and women in the United States in 1996, randomly assigned 577 to a highly active antiretroviral therapy and 579 to a largely ineffective combination therapy, and followed participants for 52 weeks. The target population was US people infected with HIV in 2006, as estimated by the Centers for Disease Control and Prevention. Results from the trial apply, albeit muted by 12%, to the target population, under the assumption that the authors have measured and correctly modeled the determinants of selection that reflect heterogeneity in the treatment effect. In simulations with a heterogeneous treatment effect, a conventional intent-to-treat estimate was biased with poor confidence limit coverage, but the proposed estimate was largely unbiased with appropriate confidence limit coverage. The proposed method standardizes observed trial results to a specified target population and thereby provides information regarding the generalizability of trial results. PMID:20547574
Population-based prevention of influenza in Dutch general practice
Hak, E; Hermens, R P; van Essen, G A; Kuyvenhoven, M M; de Melker, R A
BACKGROUND: Although the effectiveness of influenza vaccination in high-risk groups has been proven, vaccine coverage continues to be less than 50% in The Netherlands. To improve vaccination rates, data on the organizational factors, which should be targeted in population-based prevention of
Self-medication with antibiotics in a Swedish general population
Svensson, E; Haaijer-Ruskamp, FM; Lundborg, CS
To assess the extent of antibiotic self-medication in a Swedish population, a postal questionnaire was distributed to 1000 randomly selected subjects. The antibiotics used were in all but 3 cases reported to have been obtained with a prescription. Thus, prescribers are the primary target for
Quality of life profile of general Vietnamese population using EQ-5D-5L.
Nguyen, Long Hoang; Tran, Bach Xuan; Hoang Le, Quynh Ngoc; Tran, Tung Thanh; Latkin, Carl A
2017-10-11
Health-related quality of life (HRQOL) is a vital benchmark to assess the effects of health interventions and policies. Measuring HRQOL of the general population is essential to establish a reference for health outcomes evaluations. However, evidence on HRQOL of general populations in low and middle income countries is very limited. This study aimed to measure HRQOL of the Vietnamese population by using the EuroQol-5 dimensions-5 levels (EQ-5D-5L) instrument and determine its associated factors. A cross-sectional study was performed in Hanoi with 1571 residences in Hanoi, the capital city of Vietnam. EQ-5D-5L and EQ- visual analogue scale (EQ-VAS) were used to assess HRQOL. Potential covariates included socio-demographic characteristics, having acute symptoms in the last four weeks, chronic diseases in the last three months, having multiple health issues, and health service utilisation in the last twelve months. A generalized linear model was employed to identify the association between HRQOL and covariates. Overall, the mean EQ-5D utility index was 0.91 (SD = 0.15), and the mean EQ-VAS score was 87.4 (SD = 14.3). The highest proportion of respondents reporting any problems was in Usual activities (24.3%), followed by Anxiety/Depression (15.2%) and Pain/Discomfort (10.0%), while the lowest percentage was in Self-care (2.5%). Lower HRQOL composite scores were related to unemployment, lower income, higher education, living in urban areas, having chronic diseases, having multiple health issues and using health service. For any health problem self-reported by respondents, the health utility reduced by 0.02 (respiratory diseases) to 0.15 (musculoskeletal diseases). Health utility of the general population and reductions for self-reported health problems in this study are useful for future population health evaluations and comparisons. It also informs the development of interventions to reduce health problems of the general population.
70 years of the general theory of relativity
International Nuclear Information System (INIS)
Castro Diaz-Balart, F.; Cabezas Solorzano, R.
1986-06-01
In view of the 70th anniversary of the discovery of the General Theory of Relativity, an analysis was made of the special and general theories. The basic postulates, their consequences in the formulation of the theories, the main results, some aspects related to the experimental verification and its applications are presented, as are some elements of the mathematical formalism of the theories, to facilitate the logical interrelationships between its results and consequences. (author)
Using CAMAL for algebraic computations in general relativity
International Nuclear Information System (INIS)
Fitch, J.P.
1979-01-01
CAMAL is a collection of computer algebra systems developed in Cambridge, England for use mainly in theoretical physics. One of these was designed originally for general relativity calculations, although it is often used in other fields. In a recent paper Cohen, Leringe, and Sundblad compared six systems for algebraic computations applied to general relativity available in Stockholm. Here similar information for CAMAL is given and by using the same tests CAMAL is added to the comparison. (author)
Perception of radiation related risks among three population groups
International Nuclear Information System (INIS)
Mihai, L.T.; Milu, C.; Voicu, B.; Enachescu, D.
2003-01-01
A questionnaire survey was conducted among three groups that mainly differ in socioeconomic status and professional exposure to ionizing radiations. Seventy-seven (26.3%) of the respondents were professionally exposed to radiation, 35 (11.9%) were medical doctors without professional exposure and 177 (68.4%) belonged to the general population group. The level of anxiety toward radiation, expressed as a concernedness index, is significantly lower in people who are professionally exposed to radiation compared to medical doctors and general population (0.81±0.94, 1.42±1.21 and 1.72±1.34 respectively, p < 0.001). In a similar manner, concernedness index values varied with the education status, with lowest values among medical university graduates and highest among public school graduates (p < 0.001). Both university-graduated groups significantly differ from the non-university groups (p < 0.05). Knowledge about radiation and knowledge about emergency plans in nuclear accident/incident were also checked in relation with concernedness, the results confirming the hypothesis that better knowledge associates lower concernedness. The extent to which people accept the civil utilization of nuclear power is also related to concernedness and knowledge, significant associations having been found. The results suggest that a political decision in radiation matter requires a valid analysis of the public's understanding and acceptance. For that reason, it is important that radiological protection authorities develop new plans and materials for communicating with people, in order to improve knowledge upon ionizing radiation, irradiation risks and safety of nuclear energy application for civil purposes. (author)
Diffeomorphism invariance in the Hamiltonian formulation of General Relativity
International Nuclear Information System (INIS)
Kiriushcheva, N.; Kuzmin, S.V.; Racknor, C.; Valluri, S.R.
2008-01-01
It is shown that when the Einstein-Hilbert Lagrangian is considered without any non-covariant modifications or change of variables, its Hamiltonian formulation leads to results consistent with principles of General Relativity. The first-class constraints of such a Hamiltonian formulation, with the metric tensor taken as a canonical variable, allow one to derive the generator of gauge transformations, which directly leads to diffeomorphism invariance. The given Hamiltonian formulation preserves general covariance of the transformations derivable from it. This characteristic should be used as the crucial consistency requirement that must be met by any Hamiltonian formulation of General Relativity
Spinor formalism and complex-vector formalism of general relativity
International Nuclear Information System (INIS)
Han-ying, G.; Yong-shi, W.; Gendao, L.
1974-01-01
In this paper, using E. Cartan's exterior calculus, we give the spinor form of the structure equations, which leads naturally to the Newman--Penrose equations. Furthermore, starting from the spinor spaces and the el (2C) algebra, we construct the general complex-vector formalism of general relativity. We find that both the Cahen--Debever--Defrise complex-vector formalism and that of Brans are its special cases. Thus, the spinor formalism and the complex-vector formalism of general relativity are unified on the basis of the uni-modular group SL(2C) and its Lie algebra
Implications of a positive cosmological constant for general relativity.
Ashtekar, Abhay
2017-10-01
Most of the literature on general relativity over the last century assumes that the cosmological constant [Formula: see text] is zero. However, by now independent observations have led to a consensus that the dynamics of the universe is best described by Einstein's equations with a small but positive [Formula: see text]. Interestingly, this requires a drastic revision of conceptual frameworks commonly used in general relativity, no matter how small [Formula: see text] is. We first explain why, and then summarize the current status of generalizations of these frameworks to include a positive [Formula: see text], focusing on gravitational waves.
Directory of Open Access Journals (Sweden)
Sasazuki Shizuka
2006-01-01
Full Text Available Abstract Background The present study aimed to provide information on awareness of the attributable fraction of cancer causes among the Japanese general population. Methods A nationwide representative sample of 2,000 Japanese aged 20 or older was asked about their perception and level of concern about various environmental and genetic risk factors in relation to cancer prevention, as a part of an Omnibus Survey. Interviews were conducted with 1,355 subjects (609 men and 746 women. Results Among 12 risk factor candidates, the attributable fraction of cancer-causing viral and bacterial infection was considered highest (51%, followed by that of tobacco smoking (43%, stress (39%, and endocrine-disrupting chemicals (37%. On the other hand, the attributable fractions of cancer by charred fish and meat (21% and alcohol drinking (22% were considered low compared with other risk factor candidates. For most risk factors, attributable fraction responses were higher in women than in men. As a whole, the subjects tended to respond with higher values than those estimated by epidemiologic evidence in the West. The attributable fraction of cancer speculated to be genetically determined was 32%, while 36% of cancer was considered preventable by improving lifestyle. Conclusion Our results suggest that awareness of the attributable fraction of cancer causes in the Japanese general population tends to be dominated by cancer-causing infection, occupational exposure, air pollution and food additives rather than major lifestyle factors such as diet.
The general class of the vacuum spherically symmetric equations of the general relativity theory
International Nuclear Information System (INIS)
Karbanovski, V. V.; Sorokin, O. M.; Nesterova, M. I.; Bolotnyaya, V. A.; Markov, V. N.; Kairov, T. V.; Lyash, A. A.; Tarasyuk, O. R.
2012-01-01
The system of the spherical-symmetric vacuum equations of the General Relativity Theory is considered. The general solution to a problem representing two classes of line elements with arbitrary functions g 00 and g 22 is obtained. The properties of the found solutions are analyzed.
Does adversity early in life affect general population suicide rates? a cross-national study
Ritesh Bhandarkar; Ajit Shah
2011-01-01
Abstract: Background: Adversity early in life has been suggested as a protective factor for elderly suicides. However, studies examining this relationship in general population suicide rates are scarce. Methods: The relationship between general population suicide rates and four proxy measures of adversity earlier in life was examined using data from the World Health Organization and the United Nations data banks. Results: General population suicide rates were negatively correlated with the pe...
Prevalence of traumatic brain injury in the general adult population: a meta-analysis.
Frost, R Brock; Farrer, Thomas J; Primosch, Mark; Hedges, Dawson W
2013-01-01
Traumatic brain injury (TBI) is a significant public-health concern. To understand the extent of TBI, it is important to assess the prevalence of TBI in the general population. However, the prevalence of TBI in the general population can be difficult to measure because of differing definitions of TBI, differing TBI severity levels, and underreporting of sport-related TBI. Additionally, prevalence reports vary from study to study. In this present study, we used meta-analytic methods to estimate the prevalence of TBI in the adult general population. Across 15 studies, all originating from developed countries, which included 25,134 adults, 12% had a history of TBI. Men had more than twice the odds of having had a TBI than did women, suggesting that male gender is a risk factor for TBI. The adverse behavioral, cognitive and psychiatric effects associated with TBI coupled with the high prevalence of TBI identified in this study indicate that TBI is a considerable public and personal-health problem. Copyright © 2012 S. Karger AG, Basel.
Deposition and retention of plutonium in the United States general population
International Nuclear Information System (INIS)
McInroy, J.F.; Boyd, H.A.; Eutsler, B.C.
1979-01-01
Since 1959, a Los Alamos National Laboratory study has analyzed over 5000 tissues from 1100 individuals of the nonoccupationally exposed general population for fallout plutonium. These data have been useful in determining the tissue distributions and the annual baseline levels of environmental plutonium in the United States population. The effects of age, sex, date of death, cause of death and geographic location of resididence on the observed plutonium deposition have been evaluated. Because of the difference in biological turnover times of plutonium in the various organs of the body and the changing concentrations of plutonium in the atmosphere, the plutonium concentration ratios between tissues have changed as a function of time. However, our data indicate that over the past 10 years, the highest concentrations in the general population are found in the tracheobronchial lymph nodes and the liver and the lowest concentrations are in the spleen, gonads and kidney. The median body burdens of plutonium in the US population are estimated to have reached 12 pCi during the 1960's and have declined to about 2 pCi in 1977. Large errors in estimated skeletal burdens of plutonium may exist because of small specimen sample sizes and a lack of knowledge concerning the relative distribution of plutonium among the various bones of the human body
Directory of Open Access Journals (Sweden)
Ackermann-Liebrich Ursula
2007-01-01
Full Text Available Abstract Background Understanding the environmental and genetic risk factors of accelerated lung function decline in the general population is a first step in a prevention strategy against the worldwide increasing respiratory pathology of chronic obstructive pulmonary disease (COPD. Deficiency in antioxidative and detoxifying Glutathione S-transferase (GST gene has been associated with poorer lung function in children, smokers and patients with respiratory diseases. In the present study, we assessed whether low activity variants in GST genes are also associated with accelerated lung function decline in the general adult population. Methods We examined with multiple regression analysis the association of polymorphisms in GSTM1, GSTT1 and GSTP1 genes with annual decline in FEV1, FVC, and FEF25–75 during 11 years of follow-up in 4686 subjects of the prospective SAPALDIA cohort representative of the Swiss general population. Effect modification by smoking, gender, bronchial hyperresponisveness and age was studied. Results The associations of GST genotypes with FEV1, FVC, and FEF25–75 were comparable in direction, but most consistent for FEV1. GSTT1 homozygous gene deletion alone or in combination with GSTM1 homozygous gene deletion was associated with excess decline in FEV1 in men, but not women, irrespective of smoking status. The additional mean annual decline in FEV1 in men with GSTT1 and concurrent GSTM1 gene deletion was -8.3 ml/yr (95% confidence interval: -12.6 to -3.9 relative to men without these gene deletions. The GSTT1 effect on the FEV1 decline comparable to the observed difference in FEV1 decline between never and persistent smoking men. Effect modification by gender was statistically significant. Conclusion Our results suggest that genetic GSTT1 deficiency is a prevalent and strong determinant of accelerated lung function decline in the male general population.
Nonlinear Supersymmetric General Relativity and Unity of Nature
Shima, Kazunari; Tsuda, Motomu
2008-01-01
The basic idea and some physical implications of nonlinear supersymmetric general relativity (NLSUSY GR) are discussed, which give new insights into the origin of mass and the mysterious relations between the cosmology and the low energy particle physics, e.g. the spontaneous SUSY breaking scale, the cosmological constant, the (dark) energy density of the universe and the neutrino mass.
Indefinite-metric quantum field theory of general relativity, 2
International Nuclear Information System (INIS)
Nakanishi, Noboru
1978-01-01
The canonical commutation relations are analyzed in detail in the manifestly covariant quantum field theory of general relativity proposed previously. It is explicitly proved that the BRS charge is indeed the generator of the BRS transformation both in the Landau gauge and in the non-Landau one. The equivalence between the field equations and the Heisenberg equations is confirmed. (author)
Sample and population exponents of generalized Taylor’s law
Czech Academy of Sciences Publication Activity Database
Giometto, A.; Formentin, Marco; Rinaldo, A.; Cohen, J.; Maritan, A.
2015-01-01
Roč. 112, č. 25 (2015), s. 7755-7760 ISSN 0027-8424 R&D Projects: GA ČR GAP201/12/2613 Institutional support: RVO:67985556 Keywords : fluctuation scaling * multiplicative growth * power law * environmental stochasticity * Markovian environment Subject RIV: BA - General Mathematics Impact factor: 9.423, year: 2015 http://library.utia.cas.cz/separaty/2015/SI/formentin-0444162.pdf
General siting regulation and population distribution criteria for Greece
International Nuclear Information System (INIS)
Kollas, J.; Yadigaroglu, G.
1983-01-01
A new national regulation for nuclear power plant siting is described. The main body of the regulation is similar in contents to the IAEA Code of Practice in siting, but exceeds its scope in certain areas and covers all aspects of the impact of the plant on the population and the environment of the region, including non-radiological effects. The regulation is accompanied by appendices which refer to site suitability criteria with respect to the radiological consequences from the operational states of the plant and with respect to accidents, including core-melt accidents; these reflect the particular geographic and demographic situation of Greece
Heartburn and related factors in general population in Tehran ...
African Journals Online (AJOL)
East African Journal of Public Health. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 7, No 2 (2010) >. Log in or Register to get access to full text downloads.
Experimental tests of general relativity: recent progress and future directions
International Nuclear Information System (INIS)
Turyshev, S G
2009-01-01
Einstein's general theory of relativity is the standard theory of gravity, especially where the needs of astronomy, astrophysics, cosmology, and fundamental physics are concerned. As such, this theory is used for many practical purposes involving spacecraft navigation, geodesy, and time transfer. We review the foundations of general relativity, discuss recent progress in tests of relativistic gravity, and present motivations for the new generation of high-accuracy tests of new physics beyond general relativity. Space-based experiments in fundamental physics are presently capable of uniquely addressing important questions related to the fundamental laws of nature. We discuss the advances in our understanding of fundamental physics that are anticipated in the near future and evaluate the discovery potential of a number of recently proposed space-based gravitational experiments. (reviews of topical problems)
Feller, Silke; Müller, Astrid; Mayr, Andreas; Engeli, Stefan; Hilbert, Anja; de Zwaan, Martina
2015-05-01
Differences between successful long-term weight loss maintainers and the general population with regard to eating and weighing habits, non-normative eating behaviors, and eating-related and general psychopathological parameters are unknown. Self-identified weight loss maintainers from the German Weight Control Registry (GWCR, n = 494) were compared with a representative sample of the general German population (n = 2,129). The samples did not differ in current BMI. Using the same assessment instruments in both cohorts, a variety of eating-related and psychological variables were determined. The GWCR participants reported more self-weighing and higher eating frequency but less hot meal consumption and more eating-out-of-home. Binge eating, compensatory behaviors, and concerns about shape and weight were reported more often by successful weight loss maintainers. Scores of depression and worrying about health were slightly higher whereas severity of somatic symptoms was less pronounced in the GWCR participants. Overall, our data suggest that successful weight loss maintainers are characterized by more concerns about shape and weight, greater binge eating frequency, and higher use of compensatory behaviors. The latter suggests that weight loss maintenance might not only be achieved by healthy strategies but also by non-normative behaviors which might increase the vulnerability for weight regain. © 2015 The Obesity Society.
Preoperative stoma site marking in the general surgery population.
Zimnicki, Katherine M
2013-01-01
Preoperative teaching and stoma site marking are supported by research and professional organizations as interventions that can reduce the incidence of problematic stomas and improve patient outcomes. This study investigated the translation of this research into practice in the acute care surgery population. A retrospective chart review using convenience sampling was conducted at a large urban hospital in the Midwestern United States. Thirty patients underwent a surgical procedure that resulted in the creation of a fecal ostomy over a 5-month period. Descriptive statistical analysis examined the reason for surgery, preoperative length of stay (LOS), the percentage of patients who received preoperative teaching and stoma marking and the relationship between preoperative LOS and the use of preoperative teaching and stoma marking. Twenty-one of 30 patients were admitted to hospital 24 hours or more before surgery. No participants were admitted urgently. Three (14%) of those admitted for more than 24 hours received preoperative marking or teaching. There was no significant relationship between preoperative LOS and preoperative teaching and stoma marking. The opportunity exists to promote successful adaptation in this surgical population through the implementation of the evidence-based interventions of preoperative teaching and stoma marking. Additional study is needed to determine barriers to their use as well as to develop effective implementation strategies.
[Analysis of the definitive statistics of the 11th General Population and Housing Census].
Aguayo Hernandez, J R
1992-01-01
The 11th General Census of Population and Housing conducted in March 1990 enumerated 2,204,054 inhabitants in Sinaloa, for a density of 37.9 per sq. km. Sinaloa's population thus increased sevenfold from 297,000 in 1900. The proportion of Sinalioans in Mexico's population increased from 2.2% in 1900 to 2.7% in 1990. 38.4% of the population was under age 14, 57.0% was 14064, and 4.6% as over 65. The greatest challenge for the year 2010 will be to meet the demand for educational facilities, employment, and services for the growing elderly population. Sinaloa's population grew at an annual rate of 1.1 between 1980-90. 17 of its 18 municipios showed slowing growth rates between 1980-90, with only Escuinapa increasing its rate. Sinaloa's growth rate of 1.8% is still relatively high, and the population in the year 2000 is projected at 2.6 million. Population distribution and migration present problems that should be more actively addressed. Urban-urban migration is increasing in importance. In 1990, Sinaloa had 5247 localities of which only 85 had more than 2500 inhabitants and 4717 had fewer than 500. Growth of midsize localities with 500-2499 inhabitants may constitute an alternative allowing the demographic deconcentration and decentralization that Sinaloa urgently requires. The lack of jobs, infrastructure, educational and health services, housing, and food in the dispersed 4717 communities with fewer than 500 inhabitants makes them sources of emigration. Sinaloa's population is concentrated along the coast and in the 3 valleys of the north and central regions, which contain 80.8% of the population. One-third of the population lives on 12.1% of the territory in 2 municipios, while 12 municipios covering 67% of the territory contain just 24% of the population. Sinaloa's growth rate has declined from 4.3% between 1960-70 to 3.7% from 1970-80 and 1.8% in 1980-90.
Proceedings of the fourth Marcel Grossmann meeting on general relativity
International Nuclear Information System (INIS)
Ruffini, R.
1986-01-01
The Marcel Grossmann meetings were conceived with the aim of reviewing recent advances in gravitation and general relativity with the major emphasis on their mathematical foundations and physical predictions. Their main objective is to elicit contributions which deepen our understanding of space-time structures as well as to review the status of experiments verifying Einstein's Theory of Gravitation. It has been demonstrated by the previous meetings that these sessions provide physicists from various countries who are involved in research on general relativity with a unique opportunity to exchange experiences and enhance co-operation in fields of common interest. The meeting was essentially divided into 3 sub-areas; interplay between elementary particle physics and cosmology and relativistic astrophysics, classical relativity, and experimental relativity. Among the topics covered were supergravity and superstrings, bar gravitational wave detectors, black holes, classical relativity, computer relativity, cosmology and inos, early cosmology, exact solutions, Kaluza Klein theories, relativistic self-gravitating systems and quantum gravity. (Auth.)
The generalized Crewther relation in QCD and its experimental consequences
International Nuclear Information System (INIS)
Brodsky, S.J.; Gabadadze, G.T.; Kataev, A.L.; Lu, H.J.
1995-12-01
We use the BLM scale-fixing prescription to derive a renormalization-scheme invariant relation between the coefficient function for the Bjorken sum rule for polarized deep inelastic scattering and the R-ratio for the e + e - annihilation cross section. This relation provides a generalization of the Crewther relation to non-conformally invariant gauge theories. The derived relations allow one to calculate unambiguously without renormalization scale or scheme ambiguity the effective charges of the polarized Bjorken and the Gross-Llewellen Smith sum rules from the experimental value for the effective charge associated with R-ratio. Present data are consistent with the generalized Crewther relations, but measurements at higher precision and energies will be needed to decisively test these fundamental relations in QCD. (orig.)
Jansen, Philip R; Polderman, Tinca J C; Bolhuis, Koen; van der Ende, Jan; Jaddoe, Vincent W V; Verhulst, Frank C; White, Tonya; Posthuma, Danielle; Tiemeier, Henning
BACKGROUND: Genome-wide association studies in adults have identified numerous genetic variants related to psychiatric disorders and related traits, such as schizophrenia and educational attainment. However, the effects of these genetic variants on behaviour in the general population remain to be
Sudden Cardiac Death During Sports Activities in the General Population.
Narayanan, Kumar; Bougouin, Wulfran; Sharifzadehgan, Ardalan; Waldmann, Victor; Karam, Nicole; Marijon, Eloi; Jouven, Xavier
2017-12-01
Regular exercise reduces cardiovascular and overall mortality. Participation in sports is an important determinant of cardiovascular health and fitness. Regular sports activity is associated with a smaller risk of sudden cardiac death (SCD). However, there is a small risk of sports-related SCD. Sports-related SCD accounts for approximately 5% of total SCD. SCD among athletes comprises only a fraction of all sports-related SCD. Sport-related SCD has a male predominance and an average age of affliction of 45 to 50 years. Survival is better than for other SCD. This review summarizes links between sports and SCD and discusses current knowledge and controversies. Copyright © 2017 Elsevier Inc. All rights reserved.
Han, Kyu-Tae; Kim, Sun Jung; Lee, Seo Yoon; Park, Eun-Cheol
2014-01-01
After the WHO recommended HPV vaccination of the general population in 2009, government support of HPV vaccination programs was increased in many countries. However, this policy was not implemented in Korea due to perceived low cost-effectiveness. Thus, the aim of this study was to analyze the cost-utility of HPV vaccination programs targeted to high risk populations as compared to vaccination programs for the general population. Each study population was set to 100,000 people in a simulation study to determine the incremental cost-utility ratio (ICUR), then standard prevalence rates, cost, vaccination rates, vaccine efficacy, and the Quality-Adjusted Life-Years (QALYs) were applied to the analysis. In addition, sensitivity analysis was performed by assuming discounted vaccination cost. In the socially vulnerable population, QALYs gained through HPV vaccination were higher than that of the general population (General population: 1,019, Socially vulnerable population: 5,582). The results of ICUR showed that the cost of HPV vaccination was higher for the general population than the socially vulnerable population. (General population: 52,279,255 KRW, Socially vulnerable population: 9,547,347 KRW). Compared with 24 million KRW/QALYs as the social threshold, vaccination of the general population was not cost-effective. In contrast, vaccination of the socially vulnerable population was strongly cost-effective. The results suggest the importance and necessity of government support of HPV vaccination programs targeted to socially vulnerable populations because a targeted approach is much more cost-effective. The implementation of government support for such vaccination programs is a critical strategy for decreasing the burden of HPV infection in Korea.
Introduction to general relativity, black holes and cosmology
Choquet-Bruhat, Yvonne
2015-01-01
General Relativity is a beautiful geometric theory, simple in its mathematical formulation but leading to numerous consequences with striking physical interpretations: gravitational waves, black holes, cosmological models, and so on. This introductory textbook is written for mathematics students interested in physics and physics students interested in exact mathematical formulations (or for anyone with a scientific mind who is curious to know more of the world we live in), recent remarkable experimental and observational results which confirm the theory are clearly described and no specialised physics knowledge is required. The mathematical level of Part A is aimed at undergraduate students and could be the basis for a course on General Relativity. Part B is more advanced, but still does not require sophisticated mathematics. Based on Yvonne Choquet-Bruhat's more advanced text, General Relativity and the Einstein Equations, the aim of this book is to give with precision, but as simply as possible, the found...
Acceptance of genetic testing in a general population
DEFF Research Database (Denmark)
Aro, A R; Hakonen, A; Hietala, M
1997-01-01
in favour of mandatory genetic testing than other respondents. Respondents with university education were more critical towards genetic testing and expressed their worry about eugenics more often than other education groups. In conclusion, there are age, education and gender related differences...
Parenting behaviour described by mothers in a general population sample.
Thompson, Margaret J J; Raynor, Alex; Cornah, Deborah; Stevenson, Jim; Sonuga-Barke, Edmund J S
2002-03-01
To collect mothers' reports of the range of behaviours used by them in the management of their children's difficult behaviour. A cross-sectional study using an interview with both semi-structured and open-ended question routes. SAMPLING FRAME: The population of mothers with 10-year-old children living in the New Forest region of Hampshire, UK. Mothers (n=67), selected from the sampling frame, were interviewed about the range of parenting behaviours they used in the management of their children's difficult behaviour. Mothers reported a wide range of behaviours. Both authoritative (e.g. reasoning was mentioned by 42%) and authoritarian (e.g. the use of physical punishment was mentioned by 37%) behaviours were mentioned frequently. Although the different behaviours within these domains were intercorrelated, there was little overlap between the two domains. The use of praise for good behaviour seemed to be independent of other behaviours. There was no association between mothers' parenting behaviours and the behaviour problems of their children. These data suggest that parenting takes many forms, with variations of behaviour across the 'normal' range being unlikely to represent a significant risk to children's development. Public funding for parenting education should be targeted at those children who are at significant risk from extreme forms of parenting.
Directory of Open Access Journals (Sweden)
Romuald Wojtczak
2017-09-01
The authors present the first Polish neurootologic survey of epidemiology of dizziness in the general population. This condition is common in the general population, and this study indicates its prevalence in 16.4% of the inhabitants of the town and district of Bytów. It is recommendable that epidemiological studies should be carried out.
Intimate Partner Violence among General and Urban Poor Populations in Kathmandu, Nepal
Oshiro, Azusa; Poudyal, Amod K.; Poudel, Krishna C.; Jimba, Masamine; Hokama, Tomiko
2011-01-01
Comparative studies are lacking on intimate partner violence (IPV) between urban poor and general populations. The objective of this study is to identify the prevalence and risk factors of physical IPV among the general and poor populations in urban Nepal. A cross-sectional study was conducted by structured questionnaire interview. Participants…
Occurence of internet addiction in a general population sample: A latent class analysis
Rumpf, H.J.; Vermulst, A.A.; Bischof, A.; Kastirke, N.; Gürtler, D.; Bischof, G.; Meerkerk, G.J.; John, U.; Meyer, C.
2014-01-01
Background: Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. Aims: This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. Methods: A
Genetic variation in ABC transporter A1 contributes to HDL cholesterol in the general population
DEFF Research Database (Denmark)
Frikke-Schmidt, Ruth; Nordestgaard, Børge G; Jensen, Gorm B
2004-01-01
on lipid traits in 9,259 individuals from the general population. Heterozygosity for ABCA1 mutations was identified in 10% of individuals with low HDL-C only. Three of 6 nonsynonymous SNPs (V771M, V825I, and R1587K) were associated with increases or decreases in HDL-C in women in the general population...
DEFF Research Database (Denmark)
Christoffersen, Mette; Frikke-Schmidt, Ruth; Schnohr, Peter
2011-01-01
To test the hypothesis that xanthelasmata and arcus corneae, individually and combined, predict risk of ischaemic vascular disease and death in the general population.......To test the hypothesis that xanthelasmata and arcus corneae, individually and combined, predict risk of ischaemic vascular disease and death in the general population....
Helicobacter pylori Infection in the general population: A Middle Eastern perspective.
Khedmat, Hossein; Karbasi-Afshar, Reza; Agah, Shahram; Taheri, Saeed
2013-01-01
Helicobacter pylori (H.pylori) infection is probably the most important factor that has been associated with the development of gastric cancers in human populations. However, there are no reliable data on the prevalence of this infection in the Middle East. In this article, based on a comprehensive literature review, we aimed to evaluate the situation in this region. The literature has been searched for the incidence and prevalence of H.pylori infection by Pubmed and Google Scholar. Search was repeated for each of the Middle Eastern countries, and to empower the method, citations of each found article were searched for the related studies. Seventy seven reports from the countries of the Middle East region had been reviewed and they all indicated a high rate of infection either in the general population or in the dyspeptic patients, the rate seemed to be higher in patients with dyspepsia, in patients with histologically confirmed gastritis and in patients of older age groups.
Socio-demographic determinants of alcohol consumption in the Danish general population
DEFF Research Database (Denmark)
Bloomfield, Kim
2008-01-01
Aims: Little is known about specific Danish drinking patterns. This paper investigates how various socio-demographic factors are related to Danish alcohol consumption with special focus on age and sex. Methods: Data come from a national telephone survey of the Danish general population conducted...... in 2003 with a final sample size of 2,030 cases. Measures of beverage specific current drinking, overall drinking, daily drinking, heavy episodic drinking, mean consumption, volume per drinking occasion and frequency of drinking were analysed. Results: A little over 5% of the population are abstainers...... than age and sex, classical socioeconomic factors do not play a great a role in determining drinking patterns. Social integrative factors in particular influence women's drinking. Conclusions: With respect to the rest of Europe and North America, Danes consume high levels of alcohol with a large...
The motion of a charged particle in general relativity
International Nuclear Information System (INIS)
Ludvigsen, M.
1979-01-01
A new approach to the problem of the motion of a self-interacting massive charged particle in general relativity is presented. A charged Robinson-Trautman solution is used as a general relativistic model of such a particle. Such a solution is shown to generate a unique world line in its own H space, which is interpreted as the world line of the particle. Using the R-T dynamical relations, the equation of motion of the particle is derived, which, in the limiting case of zero curvature, is shown to be the same as the classical Lorentz-Dirac equation of motion. (author)
Gravitational radiation and the validity of general relativity
International Nuclear Information System (INIS)
Will, C.M.
2001-01-01
The regular observation of gravitational radiation by a world-wide network of resonant and laser-interferometric detectors will usher in a new form of astronomy. At the same time, it will provide new and interesting tests of general relativity. We review the current empirical status of general relativity, and discuss three areas in which direct observation of gravitational radiation could test the theory further: polarization of the waves, speed of the waves, and back-reaction of the waves on the evolution of the source. (author)
On the mathematical theory of classical fields and general relativity
Klainerman, S
1993-01-01
From the perspective of an analyst, like myself, the General Theory of Relativity provides an extrordinary rich and vastly virgin territory. It is the aim of my lecture to provide, ﬁrst, an account of those aspects of the theory which attract me most and second a perspective of what has been accomplished so far in that respect. In trying to state our main objectives it helps to view General Relativity in the broader context of Classical Field Theory. EinsteiniVacuum equations, or shortly E—V, is already sufﬁciently complicated. I will thus restrict my attention to them.
Canonical quantization of general relativity in discrete space-times.
Gambini, Rodolfo; Pullin, Jorge
2003-01-17
It has long been recognized that lattice gauge theory formulations, when applied to general relativity, conflict with the invariance of the theory under diffeomorphisms. We analyze discrete lattice general relativity and develop a canonical formalism that allows one to treat constrained theories in Lorentzian signature space-times. The presence of the lattice introduces a "dynamical gauge" fixing that makes the quantization of the theories conceptually clear, albeit computationally involved. The problem of a consistent algebra of constraints is automatically solved in our approach. The approach works successfully in other field theories as well, including topological theories. A simple cosmological application exhibits quantum elimination of the singularity at the big bang.
Essays in general relativity a Festschrift for Abraham Taub
Tipler, Frank J
1981-01-01
Essays in General Relativity: A Festschrift for Abraham Taub is collection of essays to honor Professor Abraham H. Taub on the occasion of his retirement from the mathematics faculty of the University of California at Berkeley. Relativistic hydrodynamics has always been a subject dear to Taub's heart. In fact, many basic results on special relativistic fluid flows are due to him, and he has been a major contributor to the study of fluid flows near shocks. The book contains 16 chapters and begins with a discussion of a geometrical approach to general relativity. This is followed by separate cha
Occurence of internet addiction in a general population sample: a latent class analysis.
Rumpf, Hans-Jürgen; Vermulst, Ad A; Bischof, Anja; Kastirke, Nadin; Gürtler, Diana; Bischof, Gallus; Meerkerk, Gert-Jan; John, Ulrich; Meyer, Christian
2014-01-01
Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. A telephone survey was conducted based on a random digit dialling procedure including landline telephone (n=14,022) and cell phone numbers (n=1,001) in participants aged 14-64. The Compulsive Internet Use Scale (CIUS) served as the basis for a LCA used to look for subgroups representing participants with Internet addiction or at-risk use. CIUS was given to participants reporting to use the Internet for private purposes at least 1 h on a typical weekday or at least 1 h on a day at the weekend (n=8,130). A 6-class model showed best model fit and included two groups likely to represent Internet addiction and at-risk Internet use. Both groups showed less social participation and the Internet addiction group less general trust in other people. Proportions of probable Internet addiction were 1.0% (CI 0.9-1.2) among the entire sample, 2.4% (CI 1.9-3.1) in the age group 14-24, and 4.0% (CI 2.7-5.7) in the age group 14-16. No difference in estimated proportions between males and females was found. Unemployment (OR 3.13; CI 1.74-5.65) and migration background (OR 3.04; CI 2.12-4.36) were related to Internet addiction. This LCA-based study differentiated groups likely to have Internet addiction and at-risk use in the general population and provides characteristics to further define this rather new disorder. © 2013 S. Karger AG, Basel.
Wang, JianLi; Sareen, Jitender; Patten, Scott; Bolton, James; Schmitz, Norbert; Birney, Arden
2014-05-01
Prediction algorithms are useful for making clinical decisions and for population health planning. However, such prediction algorithms for first onset of major depression do not exist. The objective of this study was to develop and validate a prediction algorithm for first onset of major depression in the general population. Longitudinal study design with approximate 3-year follow-up. The study was based on data from a nationally representative sample of the US general population. A total of 28 059 individuals who participated in Waves 1 and 2 of the US National Epidemiologic Survey on Alcohol and Related Conditions and who had not had major depression at Wave 1 were included. The prediction algorithm was developed using logistic regression modelling in 21 813 participants from three census regions. The algorithm was validated in participants from the 4th census region (n=6246). Major depression occurred since Wave 1 of the National Epidemiologic Survey on Alcohol and Related Conditions, assessed by the Alcohol Use Disorder and Associated Disabilities Interview Schedule-diagnostic and statistical manual for mental disorders IV. A prediction algorithm containing 17 unique risk factors was developed. The algorithm had good discriminative power (C statistics=0.7538, 95% CI 0.7378 to 0.7699) and excellent calibration (F-adjusted test=1.00, p=0.448) with the weighted data. In the validation sample, the algorithm had a C statistic of 0.7259 and excellent calibration (Hosmer-Lemeshow χ(2)=3.41, p=0.906). The developed prediction algorithm has good discrimination and calibration capacity. It can be used by clinicians, mental health policy-makers and service planners and the general public to predict future risk of having major depression. The application of the algorithm may lead to increased personalisation of treatment, better clinical decisions and more optimal mental health service planning.
Sleep deficiency and motor vehicle crash risk in the general population: a prospective cohort study.
Gottlieb, Daniel J; Ellenbogen, Jeffrey M; Bianchi, Matt T; Czeisler, Charles A
2018-03-20
Insufficient sleep duration and obstructive sleep apnea, two common causes of sleep deficiency in adults, can result in excessive sleepiness, a well-recognized cause of motor vehicle crashes, although their contribution to crash risk in the general population remains uncertain. The objective of this study was to evaluate the relation of sleep apnea, sleep duration, and excessive sleepiness to crash risk in a community-dwelling population. This was a prospective observational cohort study nested within the Sleep Heart Health Study, a community-based study of the health consequences of sleep apnea. The participants were 1745 men and 1456 women aged 40-89 years. Sleep apnea was measured by home polysomnography and questionnaires were used to assess usual sleep duration and daytime sleepiness. A follow-up questionnaire 2 years after baseline ascertained driving habits and motor vehicle crash history. Logistic regression analysis was used to examine the relation of sleep apnea and sleep duration at baseline to the occurrence of motor vehicle crashes during the year preceding the follow-up visit, adjusting for relevant covariates. The population-attributable fraction of motor vehicle crashes was estimated from the sample proportion of motor vehicle crashes and the adjusted odds ratios for motor vehicle crash within each exposure category. Among 3201 evaluable participants, 222 (6.9%) reported at least one motor vehicle crash during the prior year. A higher apnea-hypopnea index (p vehicle crashes was 10% due to sleep apnea and 9% due to sleep duration less than 7 hours. Sleep deficiency due to either sleep apnea or insufficient sleep duration is strongly associated with motor vehicle crashes in the general population, independent of self-reported excessive sleepiness.
Chronic widespread pain prevalence in the general population: A systematic review.
Andrews, P; Steultjens, M; Riskowski, J
2018-01-01
Chronic widespread pain (CWP) is a significant burden in communities. Understanding the impact of population-dependent (e.g., age, gender) and contextual-dependent (e.g. survey method, region, inequality level) factors have on CWP prevalence may provide a foundation for population-based strategies to address CWP. Therefore, the purpose of this study was to estimate the global prevalence of CWP and evaluate the population and contextual factors associated with CWP. A systematic review of CWP prevalence studies (1990-2017) in the general population was undertaken. Meta-analyses were conducted to determine CWP prevalence, and study population data and contextual factors were evaluated using a meta-regression. Thirty-nine manuscripts met the inclusion criteria. Study CWP prevalence ranged from 1.4% to 24.0%, with CWP prevalence in men ranging from 0.8% to 15.3% and 1.7% to 22.1% in women. Estimated overall CWP prevalence was 9.6% (8.0-11.2%). Meta-regression analyses showed gender, United Nations country development status, and human development index (HDI) influenced CWP prevalence, while survey method, region, methodological and reporting quality, and inequality showed no significant effect on the CWP estimate. Globally CWP affects one in ten individuals within the general population, with women more likely to experience CWP than men. HDI was noted to be the socioeconomic factor related to CWP prevalence, with those in more developed countries having a lower CWP prevalence than those in less developed countries. Most CWP estimates were from developed countries, and CWP estimates from countries with a lower socioeconomic position is needed to further refine the global estimate of CWP. This systematic review and meta-analysis updates the current global CWP prevalence by examining the population-level (e.g. age, gender) and contextual (e.g. country development status; survey style; reporting and methodologic quality) factors associated with CWP prevalence. This analyses
Heterogeneity of the jealousy phenomenon in the general population: an Italian study.
Marazziti, Donatella; Sbrana, Alfredo; Rucci, Paola; Cherici, Luca; Mungai, Francesco; Gonnelli, Chiara; Massimetti, Enrico; Raimondi, Francesca; Doria, Maria Rosaria; Spagnolli, Sabrina; Ravani, Laura; Consoli, Giorgio; Catena Dell Osso, Mario
2010-01-01
Despite the general agreement that normal jealousy is heterogenous, little is known about this specific topic. In the present study, we explored the possibility of distinguishing between four subtypes of "normal" jealousy (depressive, anxious, obsessive, and paranoid) amongst a cohort of 500 healthy university students by means of a specifically designed questionnaire, "Ouestionario della gelosia" (QUEGE). QUEGE is a self-report instrument of 30 items which explores the presence, frequency, and duration of feelings and behaviors related to jealousy. It was devised to investigate four hypothetical psychopathological profiles: depressive, paranoid, obsessive, and anxious. The factor analysis identified five rather than four clear-cut factors: self-esteem, paranoia, interpersonal Sensitivity, fear of being abandoned, and obsessionality. Women showed statistically significant lower levels of self-esteem and higher levels of obsessionality than men. Younger age (jealousy phenomenon in the general population.
Doppler frequency in interplanetary radar and general relativity
Mcvittie, G. C.
1972-01-01
The change of frequency of an interplanetary radar signal sent from the earth to another planet or to a space probe is worked out according to general relativity. The Schwarzschild spacetime is employed and its null geodesics control the motion of the signals. Exact Doppler frequency formulas are derived for one-way and two-way radar in terms of an arbitrary Schwarzschild radial coordinate. A reduction to the special relativity case is used to interpret the formulas in terms of the relative radial velocity of emitter and target. The general relativity corrections are worked out approximately for each of three possible Schwarzschild radial coordinates, and a numerical example is given. The amount of the correction is different according as one or the other of the Schwarzschild coordinates is identified with the radius vector deduced from classical celestial mechanics. The identification problem is discussed.
Cosmological perturbations in a family of deformations of general relativity
International Nuclear Information System (INIS)
Krasnov, Kirill; Shtanov, Yuri
2010-01-01
We study linear cosmological perturbations in a previously introduced family of deformations of general relativity characterized by the absence of new degrees of freedom. The homogeneous and isotropic background in this class of theories is unmodified and is described by the usual Friedmann equations. The theory of cosmological perturbations is modified and the relevant deformation parameter has the dimension of length. Gravitational perturbations of the scalar type can be described by a certain relativistic potential related to the matter perturbations just as in general relativity. A system of differential equations describing the evolution of this potential and of the stress-energy density perturbations is obtained. We find that the evolution of scalar perturbations proceeds with a modified effective time-dependent speed of sound, which, contrary to the case of general relativity, does not vanish even at the matter-dominated stage. In a broad range of values of the length parameter controlling the deformation, a specific transition from the regime of modified gravity to the regime of general relativity in the evolution of scalar perturbations takes place during the radiation domination. In this case, the resulting power spectrum of perturbations in radiation and dark matter is suppressed on the comoving spatial scales that enter the Hubble radius before this transition. We estimate the bounds on the deformation parameter for which this suppression does not lead to observable consequences. Evolution of scalar perturbations at the inflationary stage is modified but very slightly and the primordial spectrum generated during inflation is not noticeably different from the one obtained in general relativity
BOOK REVIEW: Partial Differential Equations in General Relativity
Halburd, Rodney G.
2008-11-01
Although many books on general relativity contain an overview of the relevant background material from differential geometry, very little attention is usually paid to background material from the theory of differential equations. This is understandable in a first course on relativity but it often limits the kinds of problems that can be studied rigorously. Einstein's field equations lie at the heart of general relativity. They are a system of partial differential equations (PDEs) relating the curvature of spacetime to properties of matter. A central part of most problems in general relativity is to extract information about solutions of these equations. Most standard texts achieve this by studying exact solutions or numerical and analytical approximations. In the book under review, Alan Rendall emphasises the role of rigorous qualitative methods in general relativity. There has long been a need for such a book, giving a broad overview of the relevant background from the theory of partial differential equations, and not just from differential geometry. It should be noted that the book also covers the basic theory of ordinary differential equations. Although there are many good books on the rigorous theory of PDEs, methods related to the Einstein equations deserve special attention, not only because of the complexity and importance of these equations, but because these equations do not fit into any of the standard classes of equations (elliptic, parabolic, hyperbolic) that one typically encounters in a course on PDEs. Even specifying exactly what ones means by a Cauchy problem in general relativity requires considerable care. The main problem here is that the manifold on which the solution is defined is determined by the solution itself. This means that one does not simply define data on a submanifold. Rendall's book gives a good overview of applications and results from the qualitative theory of PDEs to general relativity. It would be impossible to give detailed
Indefinite-metric quantum field theory of general relativity
International Nuclear Information System (INIS)
Nakanishi, Noboru
1978-01-01
Quantum field theory of Einstein's general relativity is formulated in the indefinitemetric Hilbert space in such a way that asymptotic fields are manifestly Lorentz covariant and the physical S-matrix is unitary. The general coordinate transformation is transcribed into a q-number transformation, called the BRS transformation. Its abstract definition is presented on the basis of the BRS transformation for the Yang-Mills theory. The BRS transformation for general relativity is then explicitly constructed. The gauge-fixing Lagrangian density and the Faddeev-Popov one are introduced in such a way that their sum behaves like a scalar density under the BRS transformation. One can then proceed in the same way as in the Kugo-Ojima formalism of the Yang-Mills theory to establish the unitarity of the physical S-matrix. (author)
Myung, Woojae; Won, Hong-Hee; Fava, Maurizio; Mischoulon, David; Yeung, Albert; Lee, Dongsoo; Kim, Doh Kwan; Jeon, Hong Jin
2015-04-01
Although evidence suggests that there is an increase in suicide rates in the general population following celebrity suicide, the rates are heterogeneous across celebrities and countries. It is unclear which is the more vulnerable population according to the effect sizes of celebrity suicides to general population. All suicide victims in the general population verified by the Korea National Statistical Office and suicides of celebrity in South Korea were included for 7 years from 2005 to 2011. Effect sizes were estimated by comparing rates of suicide in the population one month before and after each celebrity suicide. The associations between suicide victims and celebrities were examined. Among 94,845 suicide victims, 17,209 completed suicide within one month after 13 celebrity suicides. Multivariate logistic regression analyses revealed that suicide victims who died after celebrity suicide were significantly likely to be of age 20-39, female, and to die by hanging. These qualities were more strongly associated among those who followed celebrity suicide with intermediate and high effect sizes than lower. Younger suicide victims were significantly associated with higher effect size, female gender, white collar employment, unmarried status, higher education, death by hanging, and night-time death. Characteristics of celebrities were significantly associated with those of general population in hanging method and gender. Individuals who commit suicide after a celebrity suicide are likely to be younger, female, and prefer hanging as method of suicide, which are more strongly associated in higher effect sizes of celebrity suicide.
General projective relativity and the vector-tensor gravitational field
International Nuclear Information System (INIS)
Arcidiacono, G.
1986-01-01
In the general projective relativity, the induced 4-dimensional metric is symmetric in three cases, and we obtain the vector-tensor, the scalar-tensor, and the scalar-vector-tensor theories of gravitation. In this work we examine the vector-tensor theory, similar to the Veblen's theory, but with a different physical interpretation
Test theories of special relativity: a general critique
International Nuclear Information System (INIS)
Maciel, A.K.A.; Tiomno, J.
1988-01-01
Absolute Spacetime Theories conceived for the purpose of testing Special Relativity (SR) are reviewed. It is found that most theories proposed were in fact SR in different coordinate systems, since in general no specific SR violations were introduced. Models based on possible SR violating mechanisms are considered. Misconceptions in recently published papers are examined. (author) [pt
Survey on Dirac equation in general relativity theory
International Nuclear Information System (INIS)
Paillere, P.
1984-10-01
Starting from an infinitesimal transformation expressed with a Killing vector and using systematically the formalism of the local tetrades, we show that, in the area of the general relativity, the Dirac equation may be formulated only versus the four local vectors which determine the gravitational potentials, their gradients and the 4-vector potential of the electromagnetic field [fr
An experiment designed to verify the general theory of relativity
International Nuclear Information System (INIS)
Surdin, Maurice
1960-01-01
The project for an experiment which uses the effect of gravitation on Maser-type clocks placed on the ground at two different heights and which is designed to verify the general theory of relativity. Reprint of a paper published in Comptes rendus des seances de l'Academie des Sciences, t. 250, p. 299-301, sitting of 11 January 1960 [fr
Spinning fluids in general relativity: a variational formulation
International Nuclear Information System (INIS)
Oliveira, H.P. de; Salim, J.M.
1990-01-01
In this paper we present a variational formulation for spinning fluids in General Relativity. In our model each volume element of the fluid has rigid microstructure. We deduce a symmetrical energy-moment tensor where there is an explicit contribution of kinetic spin energy to the total energy. (author)
Albert Einstein's 1916 Review Article on General Relativity
Sauer, Tilman
2004-01-01
The first comprehensive overview of the final version of the general theory of relativity was published by Einstein in 1916 after several expositions of preliminary versions and latest revisions of the theory in November 1915. A historical account of this review paper is given, of its prehistory, including a discussion of Einstein's collaboration with Marcel Grossmann, and of its immediate reception.
Derivation of Einstein-Cartan theory from general relativity
Petti, Richard
2015-04-01
General relativity cannot describe exchange of classical intrinsic angular momentum and orbital angular momentum. Einstein-Cartan theory fixes this problem in the least invasive way. In the late 20th century, the consensus view was that Einstein-Cartan theory requires inclusion of torsion without adequate justification, it has no empirical support (though it doesn't conflict with any known evidence), it solves no important problem, and it complicates gravitational theory with no compensating benefit. In 1986 the author published a derivation of Einstein-Cartan theory from general relativity, with no additional assumptions or parameters. Starting without torsion, Poincaré symmetry, classical or quantum spin, or spinors, it derives torsion and its relation to spin from a continuum limit of general relativistic solutions. The present work makes the case that this computation, combined with supporting arguments, constitutes a derivation of Einstein-Cartan theory from general relativity, not just a plausibility argument. This paper adds more and simpler explanations, more computational details, correction of a factor of 2, discussion of limitations of the derivation, and discussion of some areas of gravitational research where Einstein-Cartan theory is relevant.
General relativity from a gauged Wess-Zumino-Witten term
International Nuclear Information System (INIS)
Anabalon, Andres; Willison, Steven; Zanelli, Jorge
2007-01-01
In this paper two things are done. First it is shown how a four-dimensional gauged Wess-Zumino-Witten term arises from the five-dimensional Einstein-Hilbert plus Gauss-Bonnet Lagrangian with a special choice of the coefficients. Second, the way in which the equations of motion of four-dimensional General Relativity arise is exhibited
Einstein and Hilbert: The creation of general relativity
International Nuclear Information System (INIS)
Todorov, I.T.
1992-12-01
It took eight years after Einstein announced the basic physical ideas behind the relativistic gravity theory before the proper mathematical formulation of general-relativity was mastered. The efforts of the greatest physicist and of the greatest mathematician of the time was involved and reached a breathtaking concentration during the last month of the work. (author)
Proceedings of the third Marcel Grossmann meeting on general relativity
International Nuclear Information System (INIS)
Hu Ning
1983-01-01
This book contains 64 session papers presented at the 3rd Marcel Grossmann Meeting on General Relativity. The papers are divided into 10 sections including: classical problem in gravitation; alternative approaches to gravitational theory; supergravity; quantum gravity and quantum field theory in curved space; cosmology; early universe; physics of compact bodies; gravitational wave experiments; gravitational experiments; miscellaneous. (Auth.)
Generalized virial relations and the theory of subdynamics
International Nuclear Information System (INIS)
Obcemea, Ch.; Froelich, P.; Braandas, E.J.
1981-05-01
In this paper, we discuss the implication of the generalized virial relations in the spectral analysis of Liouville operators. In particular, we refer to the existence problem of the analytic continuation of these super-operators and their resolvents occurring in the reduced dynamics description of open systems. For completeness, we outline the main ideas of the subdynamics approach. (author)
Energy-momentum distribution: A crucial problem in general relativity
Sharif, M.; Fatima, T.
2005-01-01
This paper is aimed to elaborate the problem of energy–momentum in general relativity. In this connection, we use the prescriptions of Einstein, Landau–Lifshitz, Papapetrou and Möller to compute the energy–momentum densities for two exact solutions of Einstein field equations. The space–times under
Statistical equilibrium and symplectic geometry in general relativity
International Nuclear Information System (INIS)
Iglesias, P.
1981-09-01
A geometrical construction is given of the statistical equilibrium states of a system of particles in the gravitational field in general relativity. By a method of localization variables, the expression of thermodynamic values is given and the compatibility of this description is shown with a macroscopic model of a relativistic continuous medium for a given value of the free-energy function [fr
Collineations of the curvature tensor in general relativity
Indian Academy of Sciences (India)
The general theory of relativity, which is a field theory of gravitation, is described by the Einstein field equations. These equations whose fundamental constituent is the space-time metric gij, are highly non-linear partial differential equations and, therefore it is very difficult to obtain exact solutions. They become still more diffi-.
The general theory of relativity: the first thirty years
International Nuclear Information System (INIS)
Chandrasekhar, S.
1980-01-01
The principal landmarks in the development of general relativity (exclusive of cosmology) during the first 30 years after its founding are presented. The emergence of the new gravitational laws, their experimental consequences and the consequent growth of the present concern with gravitational collapse and black holes are traced. (U.K.)
Scalar fields and cosmic censorship hypothesis in general relativity
International Nuclear Information System (INIS)
Parnovs'kij, S.L.; Gajdamaka, O.Z.
2004-01-01
We discuss an influence of the presence of some nonstandard scalar fields in the vicinity of naked time-like singularity on the type and properties of this singularity. The main goal is to study the validity of the Penrose's Cosmic Censorship hypothesis in the General Relativity
Probing Students' Understanding of Some Conceptual Themes in General Relativity
Bandyopadhyay, Atanu; Kumar, Arvind
2010-01-01
This work is an attempt to see how physics undergraduates view the basic ideas of general relativity when they are exposed to the topic in a standard introductory course. Since the subject is conceptually and technically difficult, we adopted a "case studies" approach, focusing in depth on about six students who had just finished a one semester…
Galileons as the Scalar Analogue of General Relativity
Klein, Remko; Ozkan, Mehmet; Roest, Diederik
2016-01-01
We establish a correspondence between general relativity with diffeomorphism invariance and scalar field theories with Galilean invariance: notions such as the Levi-Civita connection and the Riemann tensor have a Galilean counterpart. This suggests Galilean theories as the unique nontrivial
Directory of Open Access Journals (Sweden)
Berger Wolfgang
2008-04-01
Full Text Available Abstract Background Severe alpha1-antitrypsin (AAT deficiency associated with low AAT blood concentrations is an established genetic COPD risk factor. Less is known about the respiratory health impact of variation in AAT serum concentrations in the general population. We cross-sectionally investigated correlates of circulating AAT concentrations and its association with FEV1. Methods In 5187 adults (2669 females with high-sensitive c-reactive protein (CRP levels ≤ 10 mg/l from the population-based Swiss SAPALDIA cohort, blood was collected at the time of follow-up examination for measuring serum AAT and CRP. Results Female gender, hormone intake, systolic blood pressure, age in men and in postmenopausal women, as well as active and passive smoking were positively, whereas alcohol intake and BMI inversely correlated with serum AAT levels, independent of CRP adjustment. We observed an inverse association of AAT with FEV1 in the total study population (p Conclusion The results of this population-based study reflect a complex interrelationship between tobacco exposure, gender related factors, circulating AAT, systemic inflammatory status and lung function.
The Role of Self-Compassion in Buffering Symptoms of Depression in the General Population.
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Annett Körner
Full Text Available Self-compassion, typically operationalized as the total score of the Self-Compassion Scale (SCS; Neff, 2003b, has been shown to be related to increased psychological well-being and lower depression in students of the social sciences, users of psychology websites and psychotherapy patients. The current study builds on the existing literature by examining the link between self-compassion and depressive symptomatology in a sample representative of the German general population (n = 2,404. The SCS subscales of self-judgment, isolation, and over-identification, and the "self-coldness", composite score, which encompass these three negative subscales, consistently differed between subsamples of individuals without any depressive symptoms, with any depressive syndromes, and with major depressive disorder. The contribution of the positive SCS subscales of self-kindness, common humanity, and mindfulness to the variance in depressive symptomatology was almost negligible. However, when combined to a "self-compassion composite", the positive SCS subscales significantly moderated the relationship between "self-coldness" and depressive symptoms in the general population. This speaks for self-compassion having the potential to buffer self-coldness related to depression--providing an argument for interventions that foster self-caring, kind, and forgiving attitudes towards oneself.
Connallon, Tim; Clark, Andrew G
2012-04-01
Antagonistic selection--where alleles at a locus have opposing effects on male and female fitness ("sexual antagonism") or between components of fitness ("antagonistic pleiotropy")--might play an important role in maintaining population genetic variation and in driving phylogenetic and genomic patterns of sexual dimorphism and life-history evolution. While prior theory has thoroughly characterized the conditions necessary for antagonistic balancing selection to operate, we currently know little about the evolutionary interactions between antagonistic selection, recurrent mutation, and genetic drift, which should collectively shape empirical patterns of genetic variation. To fill this void, we developed and analyzed a series of population genetic models that simultaneously incorporate these processes. Our models identify two general properties of antagonistically selected loci. First, antagonistic selection inflates heterozygosity and fitness variance across a broad parameter range--a result that applies to alleles maintained by balancing selection and by recurrent mutation. Second, effective population size and genetic drift profoundly affect the statistical frequency distributions of antagonistically selected alleles. The "efficacy" of antagonistic selection (i.e., its tendency to dominate over genetic drift) is extremely weak relative to classical models, such as directional selection and overdominance. Alleles meeting traditional criteria for strong selection (N(e)s > 1, where N(e) is the effective population size, and s is a selection coefficient for a given sex or fitness component) may nevertheless evolve as if neutral. The effects of mutation and demography may generate population differences in overall levels of antagonistic fitness variation, as well as molecular population genetic signatures of balancing selection.
On stability relative to vector elements of the orbit in general relativity motion
International Nuclear Information System (INIS)
Abdil'din, M.M.; Bejsenova, N.A.
2002-01-01
In this work a question of a new type of stability - stability relative to vector elements of the orbit is considered in general relativity mechanics in case of the Lenze-Thirring and two body rotation. (author)
Popova, Svetlana; Patra, Jayadeep; Mohapatra, Satya; Fischer, Benedikt; Rehm, Jürgen
2009-01-01
Medical prescriptions for opioids as well as their non-medical use have increased in Canada in recent years. This study aimed to estimate the number of non-medical prescription opioid (PO) users in the general and street drug using populations in Canada. The number of non-medical PO users among the general population and the number of non-medical PO users, heroin users, or both among the street drug using population was estimated for Canada and for the most populous Canadian provinces. Different estimation methods were used: 1) the number of non-medical PO users in the Canadian general population was estimated based on Canadian availability data, and the ratio of US availability to non-medical PO use from US survey data; 2) numbers within the street drug using population were indirectly estimated based on overdose death data, and a key informants survey. Distribution and trends by usage of opioids were determined by using the multi-site Canadian OPICAN cohort data. Between 321,000 to 914,000 non-medical PO users were estimated to exist among the general population in Canada in 2003. The estimated number of non-medical PO users, heroin users, or both among the street drug using population was about 72,000, with more individuals using nonmedical PO than heroin in 2003. Based on data from the OPICAN survey, in 2005 the majority of the street drug using population in main Canadian cities was non-medical PO users, with the exception of Vancouver and Montreal. A relative increase of 24% was observed from 2002 to 2005 in the proportion of the street drug using population who used non-medical POs only. There is an urgent need to further assess the extent and patterns of non-medical prescription opioid use, related problems and drug distribution channels in Canada.
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S. Rask
2016-04-01
Full Text Available Abstract Background Many ethnic minority populations have poorer health than the general population. However, there is limited knowledge on the possible ethnic gap in physical mobility. We aim to examine the prevalence of mobility limitations in working-age Russian, Somali and Kurdish origin migrants in comparison to the general population in Finland. We also determine whether the association between ethnic group and mobility limitation remains after taking into account socio-economic and health-related factors. Methods We used data from the Finnish Migrant Health and Wellbeing Study (Maamu and the Finnish Health 2011 Survey. The participants comprised 1880 persons aged 29–64 years. The age-adjusted prevalence of difficulties in various mobility tasks was calculated using predictive margins. Logistic regression analysis was used to examine the association between socio-economic, health- and migration-related factors and mobility limitation (self-reported difficulty in walking 500 m or stair climbing. The association between ethnic group and mobility limitation was calculated using logistic regression analysis. Results Mobility limitations were much more prevalent among Somali origin women (46 % and Kurdish origin men (32 % and women (57 % compared to men and women in the general Finnish population (5–12 %. In Russian origin men and women, the prevalence of mobility limitation (7–17 % was similar to the general Finnish population. Socio-economic and health-related factors, but not migration-related factors (time lived in Finland and language proficiency in Finnish or Swedish, were found to be associated with mobility limitation in the studied populations. Somali and Kurdish origin migrants were found to have increased odds for mobility limitation compared to the general Finnish population, even after adjusting for socio-economic and health-related factors (Somalis odds ratio [OR] 3.61; 95 % confidence interval [CI] 2.07–6.29, Kurds
Evidence for a General ADHD Factor from a Longitudinal General School Population Study
Normand, Sebastien; Flora, David B.; Toplak, Maggie E.; Tannock, Rosemary
2012-01-01
Recent factor analytic studies in Attention-Deficit/Hyperactivity Disorder (ADHD) have shown that hierarchical models provide a better fit of ADHD symptoms than correlated models. A hierarchical model includes a general ADHD factor and specific factors for inattention, and hyperactivity/impulsivity. The aim of this 12-month longitudinal study was…
Generalization of the test theory of relativity to noninertial frames
International Nuclear Information System (INIS)
Abolghasem, G.H.; Khajehpour, M.R.H.; Mansouri, R.
1988-08-01
We present a generalized test theory of special relativity, using a noninertial frame. Within the framework of the special theory of relativity the transport- and Einstein-synchronizations are equivalent on a rigidly rotating disk. But in any theory with a preferred frame such an equivalence does not hold. The time difference resulting from the two synchronization procedures is a measurable quantity within the reach of existing clock systems on the earth. The final result contains a term which depends on the angular velocity of the rotating system, and hence measures an absolute effect. This term is of crucial importance in our test theory of the special relativity. (author). 13 refs
Reformulation of the symmetries of first-order general relativity
Montesinos, Merced; González, Diego; Celada, Mariano; Díaz, Bogar
2017-10-01
We report a new internal gauge symmetry of the n-dimensional Palatini action with cosmological term (n>3 ) that is the generalization of three-dimensional local translations. This symmetry is obtained through the direct application of the converse of Noether’s second theorem on the theory under consideration. We show that diffeomorphisms can be expressed as linear combinations of it and local Lorentz transformations with field-dependent parameters up to terms involving the variational derivatives of the action. As a result, the new internal symmetry together with local Lorentz transformations can be adopted as the fundamental gauge symmetries of general relativity. Although their gauge algebra is open in general, it allows us to recover, without resorting to the equations of motion, the very well-known Lie algebra satisfied by translations and Lorentz transformations in three dimensions. We also report the analog of the new gauge symmetry for the Holst action with cosmological term, finding that it explicitly depends on the Immirzi parameter. The same result concerning its relation to diffeomorphisms and the open character of the gauge algebra also hold in this case. Finally, we consider the non-minimal coupling of a scalar field to gravity in n dimensions and establish that the new gauge symmetry is affected by this matter field. Our results indicate that general relativity in dimension greater than three can be thought of as a gauge theory.
Extent of the Immirzi ambiguity in quantum general relativity
International Nuclear Information System (INIS)
Marugan, Guillermo A Mena
2002-01-01
The Ashtekar-Barbero formulation of general relativity admits a one-parameter family of canonical transformations that preserves the expressions of the Gauss and diffeomorphism constraints. The loop quantization of the connection formalism based on each of these canonical sets leads to different predictions. This phenomenon is called the Immirzi ambiguity. It has been recently argued that this ambiguity could be generalized to the extent of a spatially dependent function instead of a parameter. This would ruin the predictability of loop quantum gravity. We prove that such expectations are not realized, so that the Immirzi ambiguity introduces exclusively a freedom in the choice of a real number. (letter to the editor)
Escape trajectories of solar sails and general relativity
Energy Technology Data Exchange (ETDEWEB)
Kezerashvili, Roman Ya. [Physics Department, New York City College of Technology, City University of New York, 300 Jay Street, Brooklyn, NY 11201 (United States); Graduate School and University Center, City University of New York, 365 Fifth Avenue, New York, NY 10016 (United States); Vazquez-Poritz, Justin F., E-mail: jvazquez-poritz@citytech.cuny.ed [Physics Department, New York City College of Technology, City University of New York, 300 Jay Street, Brooklyn, NY 11201 (United States); Graduate School and University Center, City University of New York, 365 Fifth Avenue, New York, NY 10016 (United States)
2009-11-16
General relativity can have a significant impact on the long-range escape trajectories of solar sails deployed near the sun. For example, spacetime curvature in the vicinity of the sun can cause a solar sail traveling from about 4 solar radii to 2550 AU to be deflected by on the order of a million kilometers, and should therefore be taken into account at the beginning of the mission. There are a number of smaller general relativistic effects, such as frame dragging due to the slow rotation of the sun which can cause a deflection of more than one thousand kilometers.
Escape trajectories of solar sails and general relativity
International Nuclear Information System (INIS)
Kezerashvili, Roman Ya.; Vazquez-Poritz, Justin F.
2009-01-01
General relativity can have a significant impact on the long-range escape trajectories of solar sails deployed near the sun. For example, spacetime curvature in the vicinity of the sun can cause a solar sail traveling from about 4 solar radii to 2550 AU to be deflected by on the order of a million kilometers, and should therefore be taken into account at the beginning of the mission. There are a number of smaller general relativistic effects, such as frame dragging due to the slow rotation of the sun which can cause a deflection of more than one thousand kilometers.
Directory of Open Access Journals (Sweden)
M. Hannich
2018-01-01
Full Text Available Objective. Aldosterone and high-density lipoprotein cholesterol (HDL-C are involved in many pathophysiological processes that contribute to the development of cardiovascular diseases. Previously, associations between the concentrations of aldosterone and certain components of the lipid metabolism in the peripheral circulation were suggested, but data from the general population is sparse. We therefore aimed to assess the associations between aldosterone and HDL-C, low-density lipoprotein cholesterol (LDL-C, total cholesterol, triglycerides, or non-HDL-C in the general adult population. Methods. Data from 793 men and 938 women aged 25–85 years who participated in the first follow-up of the Study of Health in Pomerania were obtained. The associations of aldosterone with serum lipid concentrations were assessed in multivariable linear regression models adjusted for sex, age, body mass index (BMI, estimated glomerular filtration rate (eGFR, and HbA1c. Results. The linear regression models showed statistically significant positive associations of aldosterone with LDL-C (β-coefficient = 0.022, standard error = 0.010, p=0.03 and non-HDL-C (β-coefficient = 0.023, standard error = 0.009, p=0.01 as well as an inverse association of aldosterone with HDL-C (β-coefficient = −0.022, standard error = 0.011, p=0.04. Conclusions. The present data show that plasma aldosterone is positively associated with LDL-C and non-HDL-C and inversely associated with HDL-C in the general population. Our data thus suggests that aldosterone concentrations within the physiological range may be related to alterations of lipid metabolism.
Hannich, M; Wallaschofski, H; Nauck, M; Reincke, M; Adolf, C; Völzke, H; Rettig, R; Hannemann, A
2018-01-01
Aldosterone and high-density lipoprotein cholesterol (HDL-C) are involved in many pathophysiological processes that contribute to the development of cardiovascular diseases. Previously, associations between the concentrations of aldosterone and certain components of the lipid metabolism in the peripheral circulation were suggested, but data from the general population is sparse. We therefore aimed to assess the associations between aldosterone and HDL-C, low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, or non-HDL-C in the general adult population. Data from 793 men and 938 women aged 25-85 years who participated in the first follow-up of the Study of Health in Pomerania were obtained. The associations of aldosterone with serum lipid concentrations were assessed in multivariable linear regression models adjusted for sex, age, body mass index (BMI), estimated glomerular filtration rate (eGFR), and HbA1c. The linear regression models showed statistically significant positive associations of aldosterone with LDL-C ( β -coefficient = 0.022, standard error = 0.010, p = 0.03) and non-HDL-C ( β -coefficient = 0.023, standard error = 0.009, p = 0.01) as well as an inverse association of aldosterone with HDL-C ( β -coefficient = -0.022, standard error = 0.011, p = 0.04). The present data show that plasma aldosterone is positively associated with LDL-C and non-HDL-C and inversely associated with HDL-C in the general population. Our data thus suggests that aldosterone concentrations within the physiological range may be related to alterations of lipid metabolism.
Knowledge about urology in the general population of Jeddah, Saudi Arabia
Directory of Open Access Journals (Sweden)
Ghassan A Barayan
2011-01-01
Conclusion : Although significant proportion of our population know little about the field of urology, the overall result is better when compared to North American population. The clarity of Arabic terminology related to the field may explain the difference.
Directory of Open Access Journals (Sweden)
Wagner AC
2010-09-01
Full Text Available Prevalence of generalised anxiety disorders is widespread in Great Britain. Previous small-scale research has shown variations in minor tranquiliser prescribing, identifying several potential predictors of prescribing volume. Objective: This study aimed to investigate the relationship between general practice minor tranquiliser prescribing rates and practice population and general practice characteristics for all general practices in England.Methods: Multiple regression analysis of minor tranquiliser prescribing volumes during 2004/2005 for 8,291 English general practices with general practice and population variables obtained from the General Medical Services (GMS statistics, Quality and Outcomes Framework (QOF, 2001 Census and 2004 Index of Multiple Deprivation (IMD. Results: The highest rates of minor tranquiliser prescribing were in areas with the greatest local deprivation while general practices situated in areas with larger proportions of residents of black ethnic origin had lower rates of prescribing. Other predictors of increased prescribing were general practices with older general practitioners and general practices with older registered practice populations.Conclusion: Our findings show that there is wide variation of minor tranquilisers prescribing across England which has implications regarding access to treatment and inequity of service provision. Future research should determine the barriers to equitable prescribing amongst general practices serving larger populations of black ethnic origin.
Respiratory symptoms and occupation: a cross-sectional study of the general population
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Smit Henriëtte A
2002-12-01
Full Text Available Abstract Background This study focused on respiratory symptoms due to occupational exposures in a contemporary general population cohort. Subjects were from the Dutch Monitoring Project on Risk Factors for Chronic Diseases (MORGEN. The composition of this population enabled estimation of respiratory risks due to occupation from the recent past for both men and women. Methods The study subjects (aged 20–59 were all inhabitants of Doetinchem, a small industrial town, and came from a survey of a random sample of 1104 persons conducted in 1993. A total of 274 cases with respiratory symptoms (subdivided in asthma and bronchitis symptoms and 274 controls without symptoms were matched for age and sex. Relations between industry and occupation and respiratory symptoms were explored and adjusted for smoking habits and social economic status. Results Employment in the 'construction' (OR = 3.38; 95%CI 1.02 – 11.27, 'metal' (OR = 3.17; 95%CI 0. 98 – 10.28, 'rubber, plastics and synthetics' (OR = 6.52; 95%CI 1.26 – 53.80, and 'printing' industry (OR = 3.96; 95%CI 0.85 – 18.48 were positively associated with chronic bronchitis symptoms. In addition, the 'metal' industry was found to be weakly associated with asthma symptoms (OR = 2.59; 95%CI 0.87 – 7.69. Duration of employment within these industries was also positively associated with respiratory symptoms. Conclusion Respiratory symptoms in the general population are traceable to employment in particular industries even in a contemporary cohort with relatively young individuals.
Lifestyle factors and experience of respiratory alarm symptoms in the general population
DEFF Research Database (Denmark)
Sele, Lisa Maria Falk; Balasubramaniam, Kirubakaran; Elnegaard, Sandra
2015-01-01
BACKGROUND: The first step in the diagnosis of lung cancer is for individuals in the general population to recognise respiratory alarm symptoms (RAS). Knowledge is sparse about RAS and factors associated with experiencing RAS in the general population. This study aimed to estimate the prevalence...... of RAS in the general population, and to analyse possible associations between lifestyle factors and experiencing RAS. METHODS: A web-based survey comprising 100 000 individuals randomly selected from the Danish Civil Registration System. Items regarding experience of RAS (prolonged coughing, shortness...
Comparison of Einstein-Boltzmann solvers for testing general relativity
Bellini, E.; Barreira, A.; Frusciante, N.; Hu, B.; Peirone, S.; Raveri, M.; Zumalacárregui, M.; Avilez-Lopez, A.; Ballardini, M.; Battye, R. A.; Bolliet, B.; Calabrese, E.; Dirian, Y.; Ferreira, P. G.; Finelli, F.; Huang, Z.; Ivanov, M. M.; Lesgourgues, J.; Li, B.; Lima, N. A.; Pace, F.; Paoletti, D.; Sawicki, I.; Silvestri, A.; Skordis, C.; Umiltà, C.; Vernizzi, F.
2018-01-01
We compare Einstein-Boltzmann solvers that include modifications to general relativity and find that, for a wide range of models and parameters, they agree to a high level of precision. We look at three general purpose codes that primarily model general scalar-tensor theories, three codes that model Jordan-Brans-Dicke (JBD) gravity, a code that models f (R ) gravity, a code that models covariant Galileons, a code that models Hořava-Lifschitz gravity, and two codes that model nonlocal models of gravity. Comparing predictions of the angular power spectrum of the cosmic microwave background and the power spectrum of dark matter for a suite of different models, we find agreement at the subpercent level. This means that this suite of Einstein-Boltzmann solvers is now sufficiently accurate for precision constraints on cosmological and gravitational parameters.
New ghost-free extensions of general relativity
International Nuclear Information System (INIS)
Mann, R.B.
1989-01-01
The method of algebraic extension is shown to yield a large class of gravitational theories which are extensions of general relativity. Requiring positivity of energy in the flat-space limit of such theories provides some constraints, but a large set of theories of potential phenomenological interest survives this condition. Explicit examples of such theories include the non-symmetric gravitational theory, algebraically extended Hilbert gravity and a one-parameter family of theories with dynamical torsion. In general such theories do not alter general relativistic post-Newtonian predictions for time delay experiments; rather they alter the non-linearities of the post-Newtonian gravitational potential. Such effects may be probed by measuring periastron shifts, as in the eclipsing binary systems Di Her and As Cam, as well as in the binary pulsar PSR 1913 + 16 (author)
Gender differences in a resources-demands model in the general population.
Kocalevent, Rüya-Daniela; Klapp, Burghard F; Albani, Cornelia; Brähler, Elmar
2014-09-01
The population-based study examined postulated effects, derived from a resources-demands-model about gender-related aspects of self-efficacy, optimism, chronic stress, and exhaustion. Data acquisition was carried out by a market research institute with a multi-topic questionnaire in the general population (N = 2,552). Instruments administered were the Questionnaire for Self-Efficacy and Optimism, the Trier Inventory for Chronic Stress, and the Chalder-Fatigue-Scale. Households and target persons were selected randomly. The analyses focused on structural equation modeling. There were significant differences in structural relations among the resource paths. In particular, significant gender differences were found with respect to self-efficacy, and among the exhaustion paths, namely in the mental dimension of exhaustion. The observed measures of chronic stress were found to be operating equivalently for both genders. Results suggest that resources play an important role in the understanding of how chronic stress is preceded and may lead to exhaustion in both genders. Personal resources seem to be more expressed by men than by woman, for whom the relation of resources to health is of greater importance than for men.
Isotropic extensions of the vacuum solutions in general relativity
Energy Technology Data Exchange (ETDEWEB)
Molina, C. [Universidade de Sao Paulo (USP), SP (Brazil); Martin-Moruno, Prado [Victoria University of Wellington (New Zealand); Gonzalez-Diaz, Pedro F. [Consejo Superior de Investigaciones Cientificas, Madrid (Spain)
2012-07-01
Full text: Spacetimes described by spherically symmetric solutions of Einstein's equations are of paramount importance both in astrophysical applications and theoretical considerations. And among those, black holes are highlighted. In vacuum, Birkhoff's theorem and its generalizations to non-asymptotically flat cases uniquely fix the metric as the Schwarzschild, Schwarzschild-de Sitter or Schwarzschild-anti-de Sitter geometries, the vacuum solutions of the usual general relativity with zero, positive or negative values for the cosmological constant, respectively. In this work we are mainly interested in black holes in a cosmological environment. Of the two main assumptions of the cosmological principle, homogeneity is lost when compact objects are considered. Nevertheless isotropy is still possible, and we enforce this condition. Within this context, we investigate spatially isotropic solutions close - continuously deformable - to the usual vacuum solutions. We obtain isotropic extensions of the usual spherically symmetric vacuum geometries in general relativity. Exact and perturbative solutions are derived. Maximal extensions are constructed and their causal structures are discussed. The classes of geometries obtained include black holes in compact and non-compact universes, wormholes in the interior region of cosmological horizons, and anti-de Sitter geometries with excess/deficit solid angle. The tools developed here are applicable in more general contexts, with extensions subjected to other constraints. (author)
Noncommutative unification of general relativity and quantum mechanics
International Nuclear Information System (INIS)
Heller, Michael; Pysiak, Leszek; Sasin, Wieslaw
2005-01-01
We present a model unifying general relativity and quantum mechanics based on a noncommutative geometry. This geometry is developed in terms of a noncommutative algebra A which is defined on a transformation groupoid Γ given by the action of a noncompact group G on the total space E of a principal fiber bundle over space-time M. The case is important since to obtain physical effects predicted by the model we should assume that G is a Lorentz group or some of its representations. We show that the generalized Einstein equation of the model has the form of the eigenvalue equation for the generalized Ricci operator, and all relevant operators in the quantum sector of the model are random operators; we study their dynamics. We also show that the model correctly reproduces general relativity and the usual quantum mechanics. It is interesting that the latter is recovered by performing the measurement of any observable. In the act of such a measurement the model 'collapses' to the usual quantum mechanics
General Theory of Relativity: Will It Survive the Next Decade?
Bertolami, Orfeu; Paramos, Jorge; Turyshev, Slava G.
2006-01-01
The nature of gravity is fundamental to our understanding of our own solar system, the galaxy and the structure and evolution of the Universe. Einstein's general theory of relativity is the standard model that is used for almost ninety years to describe gravitational phenomena on these various scales. We review the foundations of general relativity, discuss the recent progress in the tests of relativistic gravity, and present motivations for high-accuracy gravitational experiments in space. We also summarize the science objectives and technology needs for the laboratory experiments in space with laboratory being the entire solar system. We discuss the advances in our understanding of fundamental physics anticipated in the near future and evaluate discovery potential for the recently proposed gravitational experiments.
Academic Training: Einstein and beyond: Introduction to General relativity
Françoise Benz
2005-01-01
2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 3, 4, 5, 6, 7 October from 11:00 to 12:00 - Main Auditorium, bldg. 500 Einstein and beyond: Introduction to General relativity by N. Straumann / Institut fur theoretische physics, Univ. Zürich We review the enduring achievements of Einstein's papers of 1905 and their impact on the further developments in physics. Program : Lectures I and II:Einstein's Contributions to Statistical Mechanics and Quantum Theory Lecture III:Einstein's Thesis at the University of Zürich Lecture IV: From Special to General Relativity Lecture V: The History and the Mystery of the Cosmological Constant ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch
Relations between task delegation and job satisfaction in general practice
DEFF Research Database (Denmark)
Riisgaard, Helle; Nexøe, Jørgen; Videbæk Le, Jette
2016-01-01
practitioners' and their staff's job satisfaction appears to be sparse even though job satisfaction is acknowledged as an important factor associated with both patient satisfaction and medical quality of care. Therefore, the overall aim of this study was 1) to review the current research on the relation between...... task delegation and general practitioners' and their staff's job satisfaction and, additionally, 2) to review the evidence of possible explanations for this relation. METHODS: A systematic literature review. We searched the four databases PubMed, Cinahl, Embase, and Scopus systematically. The immediate...... attitude towards task delegation was positive and led to increased job satisfaction, probably because task delegation comprised a high degree of work autonomy. CONCLUSIONS: The few studies included in our review suggest that task delegation within general practice may be seen by the staff as an overall...
Testing General Relativity with the Shadow Size of Sgr A(*).
Johannsen, Tim; Broderick, Avery E; Plewa, Philipp M; Chatzopoulos, Sotiris; Doeleman, Sheperd S; Eisenhauer, Frank; Fish, Vincent L; Genzel, Reinhard; Gerhard, Ortwin; Johnson, Michael D
2016-01-22
In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size may also depend strongly on parametric deviations from the Kerr metric. Based on a reconstructed image of Sagittarius A^{*} (Sgr A^{*}) from a simulated one-day observing run of a seven-station Event Horizon Telescope (EHT) array, we employ a Markov chain Monte Carlo algorithm to demonstrate that such an observation can measure the angular radius of the shadow of Sgr A^{*} with an uncertainty of ∼1.5 μas (6%). We show that existing mass and distance measurements can be improved significantly when combined with upcoming EHT measurements of the shadow size and that tight constraints on potential deviations from the Kerr metric can be obtained.
A century of general relativity: astrophysics and cosmology.
Blandford, R D
2015-03-06
One hundred years after its birth, general relativity has become a highly successful physical theory in the sense that it has passed a large number of experimental and observational tests and finds extensive application to a wide variety of cosmic phenomena. It remains an active area of research as new tests are on the way, epitomized by the exciting prospect of detecting gravitational waves from merging black holes. General relativity is the essential foundation of the standard model of cosmology and underlies our description of the black holes and neutron stars that are ultimately responsible for the most powerful and dramatic cosmic sources. Its interface with physics on the smallest and largest scales will continue to provide fertile areas of investigation in its next century. Copyright © 2015, American Association for the Advancement of Science.
A student's manual for A first course in general relativity
Scott, Robert B
2016-01-01
This comprehensive student manual has been designed to accompany the leading textbook by Bernard Schutz, A First Course in General Relativity, and uses detailed solutions, cross-referenced to several introductory and more advanced textbooks, to enable self-learners, undergraduates and postgraduates to master general relativity through problem solving. The perfect accompaniment to Schutz's textbook, this manual guides the reader step-by-step through over 200 exercises, with clear easy-to-follow derivations. It provides detailed solutions to almost half of Schutz's exercises, and includes 125 brand new supplementary problems that address the subtle points of each chapter. It includes a comprehensive index and collects useful mathematical results, such as transformation matrices and Christoffel symbols for commonly studied spacetimes, in an appendix. Supported by an online table categorising exercises, a Maple worksheet and an instructors' manual, this text provides an invaluable resource for all students and in...
van der Sande, Marianne; Teunis, Peter; Sabel, Rob
2008-07-09
Governments are preparing for a potential influenza pandemic. Therefore they need data to assess the possible impact of interventions. Face-masks worn by the general population could be an accessible and affordable intervention, if effective when worn under routine circumstances. We assessed transmission reduction potential provided by personal respirators, surgical masks and home-made masks when worn during a variety of activities by healthy volunteers and a simulated patient. All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers). Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission.
A theory of strong interactions ''from'' general relativity
International Nuclear Information System (INIS)
Caldirola, P.; Recami, E.
1979-01-01
In this paper a previous letter (where, among other things, a classical ''quark confinement'' was derived from general relativity plus dilatation-covariance), is completed by showing that the theory is compatible also with quarks ''asymptotic freedom''. Then -within a bi-scale theory of gravitational and strong interactions- a classical field theory is proposed for the (strong) interactions between hadrons. Various consequences are briefly analysed
On the geometry of null congruences in general relativity
International Nuclear Information System (INIS)
Ahsan, Zafar; Malik, N.P.
1977-01-01
Some theorems for the null congruences within the framework of general theory of relativity are given. These theorems are important in themselves as they illustrate the geometric meaning of the spin coefficients. The newly developed Geroch-Held-Penrose (GHP) formalism has been used throughout the investigations. The salient features of GHP formalism that are necessary for the present work are given and these techniques are applied to a pair of null congruences C(l) and C(n). (author)
Testing general relativity at cosmological scales: Implementation and parameter correlations
International Nuclear Information System (INIS)
Dossett, Jason N.; Ishak, Mustapha; Moldenhauer, Jacob
2011-01-01
The testing of general relativity at cosmological scales has become a possible and timely endeavor that is not only motivated by the pressing question of cosmic acceleration but also by the proposals of some extensions to general relativity that would manifest themselves at large scales of distance. We analyze here correlations between modified gravity growth parameters and some core cosmological parameters using the latest cosmological data sets including the refined Cosmic Evolution Survey 3D weak lensing. We provide the parametrized modified growth equations and their evolution. We implement known functional and binning approaches, and propose a new hybrid approach to evolve the modified gravity parameters in redshift (time) and scale. The hybrid parametrization combines a binned redshift dependence and a smooth evolution in scale avoiding a jump in the matter power spectrum. The formalism developed to test the consistency of current and future data with general relativity is implemented in a package that we make publicly available and call ISiTGR (Integrated Software in Testing General Relativity), an integrated set of modified modules for the publicly available packages CosmoMC and CAMB, including a modified version of the integrated Sachs-Wolfe-galaxy cross correlation module of Ho et al. and a new weak-lensing likelihood module for the refined Hubble Space Telescope Cosmic Evolution Survey weak gravitational lensing tomography data. We obtain parameter constraints and correlation coefficients finding that modified gravity parameters are significantly correlated with σ 8 and mildly correlated with Ω m , for all evolution methods. The degeneracies between σ 8 and modified gravity parameters are found to be substantial for the functional form and also for some specific bins in the hybrid and binned methods indicating that these degeneracies will need to be taken into consideration when using future high precision data.
Canonical perturbation theory in linearized general relativity theory
International Nuclear Information System (INIS)
Gonzales, R.; Pavlenko, Yu.G.
1986-01-01
Canonical perturbation theory in linearized general relativity theory is developed. It is shown that the evolution of arbitrary dynamic value, conditioned by the interaction of particles, gravitation and electromagnetic fields, can be presented in the form of a series, each member of it corresponding to the contribution of certain spontaneous or induced process. The main concepts of the approach are presented in the approximation of a weak gravitational field
The role of general relativity in the uncertainty principle
International Nuclear Information System (INIS)
Padmanabhan, T.
1986-01-01
The role played by general relativity in quantum mechanics (especially as regards the uncertainty principle) is investigated. It is confirmed that the validity of time-energy uncertainty does depend on gravitational time dilation. It is also shown that there exists an intrinsic lower bound to the accuracy with which acceleration due to gravity can be measured. The motion of equivalence principle in quantum mechanics is clarified. (author)
Introduction to General Relativity and Black Holes (5/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (3/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (1/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (2/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
Introduction to General Relativity and Black Holes (4/5)
CERN. Geneva
2001-01-01
Conceptual foundations of General Relativity (GR). Uniqueness of GR. Mathematical framework: tensor calculus, Riemannian geometry, connection, 'spin' connection, curvature, Cartan's form calculus. Hilbert-Einstein action, Einstein equations. Weak gravitational fields. Post Newtonian Approximation. Gravitanional Waves. Exact solutions. Killing vectors. Experimental tests. Black Holes: extensions of the Schwarzschild solution; Kerr-Newman holes; no-hair theorems; energtics of black holes; the membrane approach; quantum mechanics of black holes; Bekenstein entropy; Hawking temperature; black holes and string theory.
New relativistic generalization of the Heisenberg commutation relations
International Nuclear Information System (INIS)
Bohm, A.; Loewe, M.; Magnollay, P.; Tarlini, M.; Aldinger, R.R.; Kielanowski, P.
1984-01-01
A relativistic generalization of the Heisenberg commutation relations is suggested which is different from the conventional ones used for the intrinsic coordinates and momenta in the relativistic oscillator model and the relativistic string. This new quantum relativistic oscillator model is determined by the requirement that it gives a unified description of relativistic vibrations and rotations and contracts in the nonrelativistic limit c -1 →0 into the usual nonrelativistic harmonic oscillator
Loch, Alexandre Andrade; Hengartner, Michael Pascal; Guarniero, Francisco Bevilacqua; Lawson, Fabio Lorea; Wang, Yuan-Pang; Gattaz, Wagner Farid; Rössler, Wulf
2013-02-28
Findings on stigmatizing attitudes toward individuals with schizophrenia have been inconsistent in comparisons between mental health professionals and members of the general public. In this regard, it is important to obtain data from understudied sociocultural settings, and to examine how attitudes toward mental illness vary in such settings. Nationwide samples of 1015 general population individuals and 1414 psychiatrists from Brazil were recruited between 2009 and 2010. Respondents from the general population were asked to identify an unlabeled schizophrenia case vignette. Psychiatrists were instructed to consider "someone with stabilized schizophrenia". Stereotypes, perceived prejudice and social distance were assessed. For the general population, stigma determinants replicated findings from the literature. The level of the vignette's identification constituted an important correlate. For psychiatrists, determinants correlated in the opposite direction. When both samples were compared, psychiatrists showed the highest scores in stereotypes and perceived prejudice; for the general population, the better they recognized the vignette, the higher they scored in those dimensions. Psychiatrists reported the lowest social distance scores compared with members of the general population. Knowledge about schizophrenia thus constituted an important determinant of stigma; consequently, factors influencing stigma should be further investigated in the general population and in psychiatrists as well. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Generalization of uncertainty relation for quantum and stochastic systems
Koide, T.; Kodama, T.
2018-06-01
The generalized uncertainty relation applicable to quantum and stochastic systems is derived within the stochastic variational method. This relation not only reproduces the well-known inequality in quantum mechanics but also is applicable to the Gross-Pitaevskii equation and the Navier-Stokes-Fourier equation, showing that the finite minimum uncertainty between the position and the momentum is not an inherent property of quantum mechanics but a common feature of stochastic systems. We further discuss the possible implication of the present study in discussing the application of the hydrodynamic picture to microscopic systems, like relativistic heavy-ion collisions.
Tests of general relativity from timing the double pulsar.
Kramer, M; Stairs, I H; Manchester, R N; McLaughlin, M A; Lyne, A G; Ferdman, R D; Burgay, M; Lorimer, D R; Possenti, A; D'Amico, N; Sarkissian, J M; Hobbs, G B; Reynolds, J E; Freire, P C C; Camilo, F
2006-10-06
The double pulsar system PSR J0737-3039A/B is unique in that both neutron stars are detectable as radio pulsars. They are also known to have much higher mean orbital velocities and accelerations than those of other binary pulsars. The system is therefore a good candidate for testing Einstein's theory of general relativity and alternative theories of gravity in the strong-field regime. We report on precision timing observations taken over the 2.5 years since its discovery and present four independent strong-field tests of general relativity. These tests use the theory-independent mass ratio of the two stars. By measuring relativistic corrections to the Keplerian description of the orbital motion, we find that the "post-Keplerian" parameter s agrees with the value predicted by general relativity within an uncertainty of 0.05%, the most precise test yet obtained. We also show that the transverse velocity of the system's center of mass is extremely small. Combined with the system's location near the Sun, this result suggests that future tests of gravitational theories with the double pulsar will supersede the best current solar system tests. It also implies that the second-born pulsar may not have formed through the core collapse of a helium star, as is usually assumed.
Explanatory and illustrative visualization of special and general relativity.
Weiskopf, Daniel; Borchers, Marc; Ertl, Thomas; Falk, Martin; Fechtig, Oliver; Frank, Regine; Grave, Frank; King, Andreas; Kraus, Ute; Müller, Thomas; Nollert, Hans-Peter; Rica Mendez, Isabel; Ruder, Hanns; Schafhitzel, Tobias; Schär, Sonja; Zahn, Corvin; Zatloukal, Michael
2006-01-01
This paper describes methods for explanatory and illustrative visualizations used to communicate aspects of Einstein's theories of special and general relativity, their geometric structure, and of the related fields of cosmology and astrophysics. Our illustrations target a general audience of laypersons interested in relativity. We discuss visualization strategies, motivated by physics education and the didactics of mathematics, and describe what kind of visualization methods have proven to be useful for different types of media, such as still images in popular science magazines, film contributions to TV shows, oral presentations, or interactive museum installations. Our primary approach is to adopt an egocentric point of view: The recipients of a visualization participate in a visually enriched thought experiment that allows them to experience or explore a relativistic scenario. In addition, we often combine egocentric visualizations with more abstract illustrations based on an outside view in order to provide several presentations of the same phenomenon. Although our visualization tools often build upon existing methods and implementations, the underlying techniques have been improved by several novel technical contributions like image-based special relativistic rendering on GPUs, special relativistic 4D ray tracing for accelerating scene objects, an extension of general relativistic ray tracing to manifolds described by multiple charts, GPU-based interactive visualization of gravitational light deflection, as well as planetary terrain rendering. The usefulness and effectiveness of our visualizations are demonstrated by reporting on experiences with, and feedback from, recipients of visualizations and collaborators.
Transfer of ERR for radiation-related leukemia from Japanese population to Chinese population
International Nuclear Information System (INIS)
Huang Liqiong; Sun Zhijuan; Zhao Yongcheng; Wang Jixian
2011-01-01
Objective: To establish a transfer model for excess relative risk (ERR) for radiation-related leukemia from Japanese population to Chinese population. Methods: Combined ERR of several subtypes of leukemia published in 1994, with the corresponding leukemia baseline incidence rates obtained from Cancer Incidence in Five Continents Vol. Ⅸ (CI5-Ⅸ) for Japanese population and Chinese population, a weighted risk transfer model was employed between an additive model and a multiplicative model, to execute ERR transfer. Results: A range of weighing factors was proposed for risk transfer models: weighing factor was 0.4 for male and 0.3 for female, acute lymphoblastic leukemia, acute myeloid leukemia and chronic myeloid leukemia. The uncertainty for ERR transfer was characterized by lognormal distribution. Conclusions: Based on the difference of baseline incidence rate for subtypes of leukemia between Japanese population and Chinese population, the transfer model and these weighing factors discussed in the present study could be applicable to transfer ERR for radiation-related leukemia from Japanese population to Chinese population. (authors)
Fung, Tak; Keenan, Kevin
2014-01-01
The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%), a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.
Directory of Open Access Journals (Sweden)
Tak Fung
Full Text Available The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%, a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L., occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.
Takase, Hiroyuki; Sugiura, Tomonori; Kimura, Genjiro; Ohte, Nobuyuki; Dohi, Yasuaki
2015-07-29
Although there is a close relationship between dietary sodium and hypertension, the concept that persons with relatively high dietary sodium are at increased risk of developing hypertension compared with those with relatively low dietary sodium has not been studied intensively in a cohort. We conducted an observational study to investigate whether dietary sodium intake predicts future blood pressure and the onset of hypertension in the general population. Individual sodium intake was estimated by calculating 24-hour urinary sodium excretion from spot urine in 4523 normotensive participants who visited our hospital for a health checkup. After a baseline examination, they were followed for a median of 1143 days, with the end point being development of hypertension. During the follow-up period, hypertension developed in 1027 participants (22.7%). The risk of developing hypertension was higher in those with higher rather than lower sodium intake (hazard ratio 1.25, 95% CI 1.04 to 1.50). In multivariate Cox proportional hazards regression analysis, baseline sodium intake and the yearly change in sodium intake during the follow-up period (as continuous variables) correlated with the incidence of hypertension. Furthermore, both the yearly increase in sodium intake and baseline sodium intake showed significant correlations with the yearly increase in systolic blood pressure in multivariate regression analysis after adjustment for possible risk factors. Both relatively high levels of dietary sodium intake and gradual increases in dietary sodium are associated with future increases in blood pressure and the incidence of hypertension in the Japanese general population. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
Genetic variation in ABC transporter A1 contributes to HDL cholesterol in the general population
DEFF Research Database (Denmark)
Frikke-Schmidt, Ruth; Nordestgaard, Børge G; Jensen, Gorm B
2004-01-01
Homozygosity for mutations in ABC transporter A1 (ABCA1) causes Tangier disease, a rare HDL-deficiency syndrome. Whether heterozygosity for genetic variation in ABCA1 also contributes to HDL cholesterol (HDL-C) levels in the general population is presently unclear. We determined whether mutations...... or single-nucleotide polymorphisms (SNPs) in ABCA1 were overrepresented in individuals with the lowest 1% (n=95) or highest 1% (n=95) HDL-C levels in the general population by screening the core promoter and coding region of ABCA1. For all nonsynonymous SNPs identified, we determined the effect of genotype...... on lipid traits in 9,259 individuals from the general population. Heterozygosity for ABCA1 mutations was identified in 10% of individuals with low HDL-C only. Three of 6 nonsynonymous SNPs (V771M, V825I, and R1587K) were associated with increases or decreases in HDL-C in women in the general population...
Directory of Open Access Journals (Sweden)
Masaki Ota, MD
2016-12-01
Conclusions: Far-field LA potentials are often recorded in the CS during sequential LA and CSM activation in the general population. The timing of LA potentials in CS recordings reflected the direction of conduction across the CSM.
Directory of Open Access Journals (Sweden)
Fouzia Tarannum
2015-01-01
Conclusion: Younger and educated females had better awareness of the association between periodontal diseases and PTLBW. Hence, efforts to educate the general female population on this association could contribute toward the reduction of the risk of PTLBW.
Genetic variation in ABCA1 predicts ischemic heart disease in the general population
DEFF Research Database (Denmark)
Frikke-Schmidt, Ruth; Nordestgaard, BG; Jensen, Gorm B
2008-01-01
We tested the hypothesis that 6 nonsynonymous single nucleotide polymorphisms (SNPs) in ATP-Binding-Cassette transporter A1 (ABCA1) affect risk of ischemic heart disease (IHD) in the general population.......We tested the hypothesis that 6 nonsynonymous single nucleotide polymorphisms (SNPs) in ATP-Binding-Cassette transporter A1 (ABCA1) affect risk of ischemic heart disease (IHD) in the general population....
Total mortality by transferrin saturation levels: two general population studies and a metaanalysis
DEFF Research Database (Denmark)
Ellervik, Christina; Tybjærg-Hansen, Anne; Nordestgaard, Børge G
2011-01-01
There is evidence for increased mortality in patients with clinically overt hereditary hemochromatosis. Whether increased transferrin saturation (TS), as a proxy for iron overload is associated with increased mortality in the general population is largely unknown.......There is evidence for increased mortality in patients with clinically overt hereditary hemochromatosis. Whether increased transferrin saturation (TS), as a proxy for iron overload is associated with increased mortality in the general population is largely unknown....
Do hemophiliacs have a higher risk for dental caries than the general population?
Žaliūnienė, Rūta; Aleksejūnienė, Jolanta; Brukienė, Vilma; Pečiulienė, Vytautė
2015-01-01
Objective: The aim of this study was to examine if patients with hemophilia were at increased risk for dental decay as compared to the general population. Materials and methods: Census sampling was used in this case–control study to recruit cases (patients with hemophilia) and a control group individuals recruited randomly from the general population, which were matched with cases based on gender, age and place of residence. Clinical examinations included dental health and salivary assessm...
Do hemophiliacs have a higher risk for dental caries than the general population?
Žaliūnienė, Rūta; Aleksejūnienė, Jolanta; Brukienė, Vilma; Pečiulienė, Vytautė
2015-01-01
Objective: The aim of this study was to examine if patients with hemophilia were at increased risk for dental decay as compared to the general population. Materials and methods: Census sampling was used in this case–control study to recruit cases (patients with hemophilia) and a control group individuals recruited randomly from the general population, which were matched with cases based on gender, age and place of residence. Clinical examinations included dental health and salivary assessment...
Hinz, A; Kittel, J; Karoff, M; Schwarz, R
2004-01-01
Objective: The aim of this study was to test age and sex effects on anxiety and depression using the Hospital Anxiety and Depression Scale HADS. Method: Sample 1 consisted of 2037 subjects of the German general population, and sample 2 comprised 2696 cardiologic patients. Results: In the group of the general population we observed a linear increase of depression and (to a lower extent) of anxiety with age. In contrast to that, the patients reached their anxiety and depression maxima in the ra...
Views on life and death of physicians, nurses, cancer patients and general population in Japan.
Sekiya, Noriyasu; Kuroda, Yujiro; Nakajima, Kasumi; Iwamitsu, Yumi; Kanai, Yoshiaki; Miyashita, Mitsunori; Kotani, Midori; Kitazawa, Yutaka; Yamashita, Hideomi; Nakagawa, Keiichi
2017-01-01
This study aimed to investigate views on life and death among physicians, nurses, cancer patients, and the general population in Japan and examine factors affecting these views. We targeted 3,140 physicians, 470 nurses, 450 cancer patients, and 3,000 individuals from the general population. We used the Death Attitudes Inventory (DAI) to measure attitudes toward life and death. The collection rates were 35% (1,093/3,140), 78% (366/470), 69% (310/450), and 39% (1,180/3,000) for physicians, nurses, patients, and the general population, respectively. We found that age, sex, social role (i.e., physician, nurse, cancer patient, and general population) were significantly correlated with DAI subscales. Compared with general population, attitudes toward death of physicians, nurses and cancer patients differed significantly even after adjusted their age and sex. Our study is the first to analyze differences in views on life and death among physicians, nurses, cancer patients, and the general population in Japan.
Annequin, Margot; Lert, France; Spire, Bruno; Dray-Spira, Rosemary
2016-01-01
Despite improved health, unemployment has increased among people living with HIV (PlwHIV) over the last decade. However, since the economic recession of 2008, unemployment also increased in the French general population. This paper aimed to determine if the increase in the unemployment rate in the HIV population was higher than that in the French general population. We used data from the ANRS-Vespa study, a repeated cross-sectional survey among two national representative samples of PlwHIV followed at hospitals in France in 2003 and 2011. We compared employment and unemployment rates between HIV-infected people (overall and according to period of HIV diagnosis) and the French general population in 2003 and 2011, using multivariate Poisson regressions adjusted for individual sociodemographic characteristics. The employment rate among PlwHIV was consistently lower than that in the general population in 2003 and 2011. In contrast, there was a trend of an increasing unemployment rate difference between PlwHIV and the general population: PlwHIV's unemployment rate was 1.48 (95% confidence interval [CI]: 1.16-1.90) times higher than that of the general population in 2003, versus 1.62 (95% CI: 1.34-1.96) times higher in 2011. This unemployment rate difference was the highest for PlwHIV diagnosed in or after 2008 (adjusted prevalence rate ratio: 2.06; 95% CI: 1.59-2.67). These results suggest that in time of economic recession, an increasing proportion of PlwHIV may be excluded from the labor market although they are willing to re-enter it. This constitutes a major issue relative to social consequences of chronic disease.
Annequin, Margot; Lert, France; Spire, Bruno; Dray-Spira, Rosemary
2016-01-01
Background Despite improved health, unemployment has increased among people living with HIV (PlwHIV) over the last decade. However, since the economic recession of 2008, unemployment also increased in the French general population. This paper aimed to determine if the increase in the unemployment rate in the HIV population was higher than that in the French general population. Methods We used data from the ANRS-Vespa study, a repeated cross-sectional survey among two national representative samples of PlwHIV followed at hospitals in France in 2003 and 2011. We compared employment and unemployment rates between HIV-infected people (overall and according to period of HIV diagnosis) and the French general population in 2003 and 2011, using multivariate Poisson regressions adjusted for individual sociodemographic characteristics. Results The employment rate among PlwHIV was consistently lower than that in the general population in 2003 and 2011. In contrast, there was a trend of an increasing unemployment rate difference between PlwHIV and the general population: PlwHIV’s unemployment rate was 1.48 (95% confidence interval [CI]: 1.16–1.90) times higher than that of the general population in 2003, versus 1.62 (95% CI: 1.34–1.96) times higher in 2011. This unemployment rate difference was the highest for PlwHIV diagnosed in or after 2008 (adjusted prevalence rate ratio: 2.06; 95% CI: 1.59–2.67). Conclusions These results suggest that in time of economic recession, an increasing proportion of PlwHIV may be excluded from the labor market although they are willing to re-enter it. This constitutes a major issue relative to social consequences of chronic disease. PMID:27814374
Guilcher, Sara J T; Newman, Alice; Jaglal, Susan B
2010-01-01
Previous qualitative and survey studies have suggested women with spinal cord injury (SCI) are screened less often for cervical cancer compared with the general population. We investigated whether cervical cancer screening rates differ between population-based women with and without traumatic SCI, matched for age and geography. A double cohort design was used, comparing women with SCI to the general population (1:4) using administrative data for Ontario, Canada. Women with SCI, identified using the Discharge Abstract Database for the fiscal years 1995-1996 to 2001-2002, were female residents of Ontario between the ages of 25 and 66, admitted to an acute care facility with a traumatic SCI (ICD-9 CM code 806 or 952). Women in the general Ontario population were randomly matched by age and geography. Screening rates were calculated from fee codes related to Papanicolaou (Pap) smear tests for a 3-year period preinjury and postinjury. There were 339 women with SCI matched to 1506 women in the general Ontario population. Screening rates pre-SCI were 55% for women with SCI and 57% during this same time period for matched women in the general population; post-SCI rates were 58% for both the two groups. Factors predicting the likelihood of receiving a Pap test for SCI cases included younger age and higher socioeconomic status. Utilization data suggest that there are no significant differences in screening rates for women with SCI compared with the general population. However, screening rates for women with SCI were significantly influenced by age as well as income.
Prevalence of Contact Allergy to p-Phenylenediamine in the European General Population
Diepgen, Thomas L.; Naldi, Luigi; Bruze, Magnus; Cazzaniga, Simone; Schuttelaar, Marie-Louise; Elsner, Peter; Goncalo, Margarida; Ofenloch, Robert; Svensson, Ake
Population-based studies on contact allergy to p-phenylenediamine (PPD) are scarce. A cross-sectional study was performed to assess the prevalence of contact allergy to PPD and its risk factors in the general population of 5 European countries. A total of 10,425 subjects were interviewed, and a
Rosbrook, Ainslie; Whittingham, Koa
2010-01-01
The high prevalence of anxiety disorders and depression within the autism spectrum disorder (ASD) population is widely recognised. This study examined the role of three potential mediating variables in the relationship between autistic traits and depressive/anxious symptomatology in the general population. Participants included 231 university…
Thyroid status and mortality in nonagenarians from long-lived families and the general population
DEFF Research Database (Denmark)
van Vliet, Nicolien A.; van der Spoel, Evie; Beekman, Marian
2017-01-01
(TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were measured. In nonagenarians from long-lived families and from the general population, associations between thyroid parameters and mortality were similar. We found no interaction between study population and parameters of thyroid status...
Prevalence of hepatitis C in the general population in the Netherlands.
Slavenburg, S.; Verduyn-Lunel, F.M.; Hermsen, J.T.; Melchers, W.J.G.; Morsche, R.H.M. te; Drenth, J.P.H.
2008-01-01
BACKGROUND: Chronic hepatitis C virus (HCV) is transmitted by blood-blood contact and this leads to high HCV prevalence in risk populations such as haemophilia patients and intravenous drug users. The prevalence in the general Dutch population is unknown, although it appears to be very low in
Predicting glycated hemoglobin levels in the non-diabetic general population
DEFF Research Database (Denmark)
Rauh, Simone P; Heymans, Martijn W; Koopman, Anitra D M
2017-01-01
AIMS/HYPOTHESIS: To develop a prediction model that can predict HbA1c levels after six years in the non-diabetic general population, including previously used readily available predictors. METHODS: Data from 5,762 initially non-diabetic subjects from three population-based cohorts (Hoorn Study, I...
DEFF Research Database (Denmark)
Lange, B; Holst, R; Thilsing, T
2013-01-01
The European Position Paper on Rhinosinusitis and Nasal Polyps describes methods to perform population-based and clinical studies on Chronic Rhinosinusitis in a standardized way and it also describes how to clinical investigate CRS. The aim of this cross sectional study was to evaluate Quality...... of life and objective findings in persons with Chronic Rhinosinusitis recruited from the general population....
Gauge stability of 3+1 formulations of general relativity
International Nuclear Information System (INIS)
Khokhlov, A M; Novikov, I D
2002-01-01
We present a general approach to the analysis of gauge stability of 3+1 formulations of general relativity (GR). Evolution of coordinate perturbations and the corresponding perturbations of lapse and shift can be described by a system of eight quasi-linear partial differential equations. Stability with respect to gauge perturbations depends on the choice of gauge and a background metric, but it does not depend on a particular form of a 3+1 system if its constrained solutions are equivalent to those of the Einstein equations. Stability of a number of known gauges is investigated in the limit of short-wavelength perturbations. All fixed gauges except a synchronous gauge are found to be ill posed. A maximal slicing gauge and its parabolic extension are shown to be ill posed as well. A necessary condition is derived for well-posedness of metric-dependent algebraic gauges. Well-posed metric-dependent gauges are found, however, to be generally unstable. Both instability and ill-posedness are associated with the existence of growing modes of coordinate perturbations related to perturbations of physical accelerations of reference frames
A database for extract solutions in general relativity
International Nuclear Information System (INIS)
Horvath, I.; Horvath, Zs.; Lukacs, B.
1993-07-01
The field of equations of General Relativity are coupled second order partial differential equations. Therefore no general method is known to generate solutions for prescribed initial and boundary conditions. In addition, the meaning of the particular coordinates cannot be known until the metric is not found. Therefore the result must permit arbitrary coordinate transformations, i.e. most kinds of approximating methods are improper. So exact solutions are necessary and each one is an individual product. For storage, retrieval and comparison database handling techniques are needed. A database of 1359 articles is shown (cross-referred at least once) published in 156 more important journals. It can be handled by dBase III plus on IBM PC's. (author) 5 refs.; 5 tabs
Solitons and action propagation according to general relativity (Part one)
International Nuclear Information System (INIS)
Stavroulakis, N.
1987-01-01
The current exposition of General Relativity involves two contradictory statements: at first it is asserted that every change in the distribution of matter brings about gravitational waves. Then it is asserted that, specifically, no gravitational effect is produced by the pulsations of a spherical source. By analysing the second statement, we conclude that it arises from a vicious circle tied up with mathematical errors which led to the Schwarzschild solution and the theory of black holes. In order to obtain the correct formulation of the problem, we establish rigorously the general form of the θ(4)-invariant space-time metrics on R x R 3 and bring out the principles allowing to associate gravitational effects with oscillating masses [fr
Charged point particles with magnetic moment in general relativity
International Nuclear Information System (INIS)
Amorim, R.; Tiomno, J.
1977-01-01
Halbwachs Lagrangean formalism for the theory of charged point particles with spin (g = 2) is generalized and formulated in General Relativity for particles of arbitrary charge and magnetic moment. Equations are obtained, both corresponding to Frenkel's condition Ssub(μν)Xsup(ν) = 0 and to Nakano's condition Ssub(μν)Psup(ν) = 0. With the later condition the exact equations are highly coupled and non linear. When linearized in the electromagnetic and gravitational fields they coincide with de Groot-Suttorp equations for vanishing gravitational fields and with Dixon-Wald equations in the absence of electromagnetic field. The equations corresponding to Frenkel's condition, when linearized in Ssub(μν), coincide with Papapetrou's and Frenkel's equations in the corresponding limits [pt
General relativity with spin and torsion: Foundations and prospects
International Nuclear Information System (INIS)
Hehl, F.W.; von der Heyde, P.; Kerlick, G.D.; Nester, J.M.
1976-01-01
A generalization of Einstein's gravitational theory is discussed in which the spin of matter as well as its mass plays a dynamical role. The spin of matter couples to a non-Riemannian structure in space-time, Cartan's torsion tensor. The theory which emerges from taking this coupling into account, the U 4 theory of gravitation, predicts, in addition to the usual infinite-range gravitational interaction mediated by the metric field, a new, very weak, spin contact interaction of gravitational origin. We summarize here all the available theoretical evidence that argues for admitting spin and torsion into a relativistic gravitational theory. Not least among this evidence is the demonstration that the U 4 theory arises as a local gauge theory for the Poincare group in space-time. The deviations of the U 4 theory from standard general relativity are estimated, and the prospects for further theoretical development are assessed
Participation in daily life of people with schizophrenia in comparison to the general population.
Lipskaya-Velikovsky, Lena; Jarus, Tal; Easterbrook, Adam; Kotler, Moshe
2016-12-01
Participation in occupations is a basic human right. Although people with schizophrenia commonly experience restrictions in participation, there is a paucity of research in this area. This study aimed to compare the participation patterns of people with schizophrenia to people without mental illness (control group). A total of 140 people of similar age and sex completed the Adults Subjective Assessment of Participation and provided demographic and health-related data. People with schizophrenia tend to participate in fewer activities and to participate alone. However, they participate with similar intensity as those in the control group. The participation patterns of people with schizophrenia are both unique and similar to those of the general population. The differences in participation raise concerns due to signs of restriction and social exclusion. However, it appears that people with schizophrenia benefit from occupation and community-based services that promote and support participation with others in diverse activities.
Trends in high-risk sexual behaviors among general population groups in China: a systematic review.
Cai, Rui; Richardus, Jan Hendrik; Looman, Caspar W N; de Vlas, Sake J
2013-01-01
The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors. We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors. We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups. Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population.
The revival of General Relativity at Princeton: Daring Conservatism
Brill, Dieter; Blum, Alexander
2018-01-01
After General Relativity was established in essentially its present form in 1915 it was celebrated as a great success of mathematical physics. But the initial hopes for this theory as a basis for all of physics began to fade in the next several decades, as General Relativity was relegated to the margins of theoretical physics. Its fate began to rise in the 1950's in a revival of interest and research that over time made gravitational physics one of the hottest research topics it is today. One center of this renaissance was Princeton, where two relative newcomers explored new and different approaches to gravitational physics. Robert Dicke showed that gravity is not as inaccessible to experiment as was thought, and John Wheeler propelled it into the mainstream by proposing highly original and imaginative consequences of Einstein's theory. We will concentrate on these ideas that, in his characteristically intriguing style, Wheeler called "Daring Conservatism" - a term well known to his associates, but one he never mentioned in print. With the aid of unpublished manuscripts and notes we will explore Daring Conservatism's origin and motivation, its successes and failures, and the legacy it left behind.
The revival of General Relativity at Princeton: Daring Conservatism
Directory of Open Access Journals (Sweden)
Brill Dieter
2018-01-01
Full Text Available After General Relativity was established in essentially its present form in 1915 it was celebrated as a great success of mathematical physics. But the initial hopes for this theory as a basis for all of physics began to fade in the next several decades, as General Relativity was relegated to the margins of theoretical physics. Its fate began to rise in the 1950's in a revival of interest and research that over time made gravitational physics one of the hottest research topics it is today. One center of this renaissance was Princeton, where two relative newcomers explored new and different approaches to gravitational physics. Robert Dicke showed that gravity is not as inaccessible to experiment as was thought, and John Wheeler propelled it into the mainstream by proposing highly original and imaginative consequences of Einstein's theory. We will concentrate on these ideas that, in his characteristically intriguing style, Wheeler called "Daring Conservatism" -- a term well known to his associates, but one he never mentioned in print. With the aid of unpublished manuscripts and notes we will explore Daring Conservatism's origin and motivation, its successes and failures, and the legacy it left behind.
Lustig, Daniel C.; Strauser, David R.
2010-01-01
Access to health insurance is one of the critical aspects of securing employment for people with disabilities. This study investigated whether vocational rehabilitation consumers secured employment with an employer who offered health insurance at similar rates to workers in the general population. In general, the results show that vocational…
The Factor Structure of ADHD in a General Population of Primary School Children
Ullebo, Anne Karin; Breivik, Kyrre; Gillberg, Christopher; Lundervold, Astri J.; Posserud, Maj-Britt
2012-01-01
Objective: To examine whether a bifactor model with a general ADHD factor and domain specific factors of inattention, hyperactivity and impulsivity was supported in a large general population sample of children. We also explored the utility of forming subscales based on the domain-specific factors. Methods: Child mental health questionnaires were…
Subset selection from Type-I and Type-II generalized logistic populations
Laan, van der M.J.; Laan, van der P.
1996-01-01
We give an introduction to the logistic and generalized logistic distributions. We obtain exact results for the probability of correct selection from Type-I and Type-II generalized logistic populations which only differ in their location parameter. Some open problems are formulated.
Amino-terminal pro-B-type natriuretic peptides: testing in general populations
DEFF Research Database (Denmark)
Lemos, J.A. de; Hildebrandt, P.
2008-01-01
Screening of general populations with amino-terminal pro-B-type natriuretic peptides (NT-proBNP) holds promise for the detection of significant underlying cardiac structural and functional abnormalities, as well as for the early detection of the propensity to develop future cardiovascular events....... In comparative studies to date, NT-proBNP performs at least as well as BNP in the detection of heart disease and prognostication in the general population. In some studies and subgroups, NT-proBNP appears to outperform BNP in population screening. More needs to be learned about noncardiac sources of NT...