95 research outputs found
The exact Darwin Lagrangian
Darwin (1920) noted that when radiation can be neglected it should be
possible to eliminate the radiation degrees-of-freedom from the action of
classical electrodynamics and keep the discrete particle degrees-of-freedom
only. Darwin derived his well known Lagrangian by series expansion in
keeping terms up to order . Since radiation is due to acceleration the
assumption of low speed should not be necessary. A Lagrangian is suggested that
neglects radiation without assuming low speed. It cures deficiencies of the
Darwin Lagrangian in the ultra-relativistic regime.Comment: 2.5 pages, no figure
Evaluating the evidence for models of life course socioeconomic factors and cardiovascular outcomes: a systematic review
BACKGROUND: A relatively consistent body of research supports an inverse graded relationship between socioeconomic status (SES) and cardiovascular disease (CVD). More recently, researchers have proposed various life course SES hypotheses, which posit that the combination, accumulation, and/or interactions of different environments and experiences throughout life can affect adult risk of CVD. Different life course designs have been utilized to examine the impact of SES throughout the life course. This systematic review describes the four most common life course hypotheses, categorizes the studies that have examined the associations between life course SES and CVD according to their life course design, discusses the strengths and weaknesses of the different designs, and summarizes the studies' findings. METHODS: This research reviewed 49 observational studies in the biomedical literature that included socioeconomic measures at a time other than adulthood as independent variables, and assessed subclinical CHD, incident CVD morbidity and/or mortality, and/or the prevalence of traditional CVD risk factors as their outcomes. Studies were categorized into four groups based upon life course design and analytic approach. The study authors' conclusions and statistical tests were considered in summarizing study results. RESULTS: Study results suggest that low SES throughout the life course modestly impacts CVD risk factors and CVD risk. Specifically, studies reviewed provided moderate support for the role of low early-life SES and elevated levels of CVD risk factors and CVD morbidity and mortality, little support for a unique influence of social mobility on CVD, and consistent support for the detrimental impact of the accumulation of negative SES experiences/conditions across the life course on CVD risk. CONCLUSIONS: While the basic life course SES study designs have various methodologic and conceptual limitations, they provide an important approach from which to examine the influence of social factors on CVD development. Some limitations may be addressed through the analysis of study cohorts followed from childhood, the evaluation of CVD risk factors in early and middle adulthood, and the use of multiple SES measures and multiple life course analysis approaches in each life course study
Does practicing hatha yoga satisfy recommendations for intensity of physical activity which improves and maintains health and cardiovascular fitness?
Background: Little is known about the metabolic and heart rate responses to a typical hatha yoga session. The purposes of this study were 1) to determine whether a typical yoga practice using various postures meets the current recommendations for levels of physical activity required to improve and maintain health and cardiovascular fitness; 2) to determine the reliability of metabolic costs of yoga across sessions; 3) to compare the metabolic costs of yoga practice to those of treadmill walking. Methods: In this observational study, 20 intermediate-to-advanced level yoga practitioners, age 31.4 ± 8.3 years, performed an exercise routine inside a human respiratory chamber (indirect calorimeter) while wearing heart rate monitors. The exercise routine consisted of 30 minutes of sitting, 56 minutes of beginner-level hatha yoga administered by video, and 10 minutes of treadmill walking at 3.2 and 4.8 kph each. Measures were mean oxygen consumption (VO2), heart rate (HR), percentage predicted maximal heart rate (%MHR), metabolic equivalents (METs), and energy expenditure (kcal). Seven subjects repeated the protocol so that measurement reliability could be established. Results: Mean values across the entire yoga session for VO2, HR, %MHR, METs, and energy/min were 0.6 L/kg/min; 93.2 beats/min; 49.4%; 2.5; and 3.2 kcal/min; respectively. Results of the ICCs (2,1) for mean values across the entire yoga session for kcal, METs, and %MHR were 0.979 and 0.973, and 0.865, respectively. Conclusion: Metabolic costs of yoga averaged across the entire session represent low levels of physical activity, are similar to walking on a treadmill at 3.2 kph, and do not meet recommendations for levels of physical activity for improving or maintaining health or cardiovascular fitness. Yoga practice incorporating sun salutation postures exceeding the minimum bout of 10 minutes may contribute some portion of sufficiently intense physical activity to improve cardio-respiratory fitness in unfit or sedentary individuals. The measurement of energy expenditure across yoga sessions is highly reliable
Gendered self-views across 62 countries: a test of competing models
Social role theory posits that binary gender gaps in agency and communion should be larger in less egalitarian countries, reflecting these countries’ more pronounced sex-based power divisions. Conversely, evolutionary and self-construal theorists suggest that gender gaps in agency and communion should be larger in more egalitarian countries, reflecting the greater autonomy support and flexible self-construction processes present in these countries. Using data from 62 countries (N = 28,640), we examine binary gender gaps in agentic and communal self-views as a function of country-level objective gender equality (the Global Gender Gap Index) and subjective distributions of social power (the Power Distance Index). Findings show that in more egalitarian countries, gender gaps in agency are smaller and gender gaps in communality are larger. These patterns are driven primarily by cross-country differences in men’s self-views and by the Power Distance Index (PDI) more robustly than the Global Gender Gap Index (GGGI). We consider possible causes and implications of these findings
Partial VP2 sequencing of canine parvovirus (CPV) strains circulating in the state of Rio de Janeiro, Brazil: detection of the new variation CPV-2c
Submitted by Sandra Infurna ([email protected]) on 2018-03-20T12:22:52Z
No. of bitstreams: 1
josepaulo_leite_etal_IOC_2010.pdf: 101175 bytes, checksum: afc5a16a8a1b43ab0a25c6edc7a18a33 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-03-20T12:30:10Z (GMT) No. of bitstreams: 1
josepaulo_leite_etal_IOC_2010.pdf: 101175 bytes, checksum: afc5a16a8a1b43ab0a25c6edc7a18a33 (MD5)Made available in DSpace on 2018-03-20T12:30:10Z (GMT). No. of bitstreams: 1
josepaulo_leite_etal_IOC_2010.pdf: 101175 bytes, checksum: afc5a16a8a1b43ab0a25c6edc7a18a33 (MD5)
Previous issue date: 2010Universidade Federal Fluminense. Instituto Biomédico. Departamento de Microbiologia e Parasitologia. Niterói, RJ, Brasil.Universidade Federal Fluminense. Instituto Biomédico. Departamento de Microbiologia e Parasitologia. Niterói, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Programa de Biodiversidade e Saúde. Rio de Janeiro, RJ. Brasil.Universidade Federal Fluminense. Instituto Biomédico. Departamento de Microbiologia e Parasitologia. Niterói, RJ, Brasil.Canine parvovirus (CPV) is the most important enteric virus for dogs and it seems to be undergoing
continuous evolution, generating new genetic and antigenic variants throughout the world. The aim of this
study was to analyze the distribution of CPV variants from 1995 to 2009 and to investigate the circulation
of the new variant CPV-2c in Rio de Janeiro, Brazil. In addition, the clinical features of CPV infection
were also reported. After CPV laboratorial confirmation by HA/HI and PCR, thirty-two fecal samples were
analyzed by sequencing a 583-bp fragment of the VP2 gene. One sample, collected in 2008 was typed as
the new type CPV-2c. All samples from 1995 to 2003 were identified as “new CPV-2a”. From 2004 to
2006, both “new CPV-2a” and CPV-2b were observed. From 2006 to 2009, most of the samples were
characterized as CPV-2b. The classical signs of CPV enteritis were observed in 16/18 CPV-2a and 5/13
CPV-2b infected puppies. These results show that continuous epidemiological surveillance of CPV strain
distribution is essential for studying the patterns of CPV-2a and 2b spread and for determining whether the
new variant CPV-2c has become permanently established in Brazilian canine population
162 Patient-derived first generation xenografts of prostate cancers: Promising tools for predicting drug responses for personalised chemotherapy
- …