166 research outputs found
Entropy of the Universe
After a discussion on several limiting cases where General Relativity turns
into less sophisticated theories, we find that in the correct thermodynamical
and cosmological weak field limit of Einstein's field equations the entropy of
the Universe is R^(3/2) -- dependent, where R stands for the radius of the
causally related Universe. Thus, entropy grows in the Universe, contrary to
Standard Cosmology prediction.Comment: To be published by International Journal of Theoretical Physic
Vector Theory of Gravity
We proposed a gravitation theory based on an analogy with electrodynamics on
the basis of a vector field. For the first time, to calculate the basic
gravitational effects in the framework of a vector theory of gravity, we use a
Lagrangian written with gravitational radiation neglected and generalized to
the case of ultra-relativistic speeds. This allows us to accurately calculate
the values of all three major gravity experiments: the values of the perihelion
shift of Mercury, the light deflection angle in the gravity field of the Sun
and the value of radar echo delay. The calculated values coincide with the
observed ones. It is shown that, in this theory, there exists a model of an
expanding Universe.Comment: 9 page
On a modified-Lorentz-transformation based gravity model confirming basic GRT experiments
Implementing Poincar\'e's `geometric conventionalism' a scalar
Lorentz-covariant gravity model is obtained based on gravitationally modified
Lorentz transformations (or GMLT). The modification essentially consists of an
appropriate space-time and momentum-energy scaling ("normalization") relative
to a nondynamical flat background geometry according to an isotropic,
nonsingular gravitational `affecting' function Phi(r). Elimination of the
gravitationally `unaffected' S_0 perspective by local composition of space-time
GMLT recovers the local Minkowskian metric and thus preserves the invariance of
the locally observed velocity of light. The associated energy-momentum GMLT
provides a covariant Hamiltonian description for test particles and photons
which, in a static gravitational field configuration, endorses the four `basic'
experiments for testing General Relativity Theory: gravitational i) deflection
of light, ii) precession of perihelia, iii) delay of radar echo, iv) shift of
spectral lines. The model recovers the Lagrangian of the Lorentz-Poincar\'e
gravity model by Torgny Sj\"odin and integrates elements of the precursor
gravitational theories, with spatially Variable Speed of Light (VSL) by
Einstein and Abraham, and gravitationally variable mass by Nordstr\"om.Comment: v1: 14 pages, extended version of conf. paper PIRT VIII, London,
2002. v2: section added on effective tensorial rank, references added,
appendix added, WEP issue deleted, abstract and other parts rewritten, same
results (to appear in Found. Phys.
A relativistic action-at-a-distance description of gravitational interactions?
It is shown that certain aspects of gravitation may be described using a
relativistic action-at-a-distance formulation. The equations of motion of the
model presented are invariant under Lorentz transformations and agree with the
equations of Einstein's theory of General Relativity, at the first
Post-Newtonian approximation, for any number of interacting point masses
The Determinants of young Adult Social well-being and Health (DASH) study: diversity, psychosocial determinants and health.
Purpose: The Determinants of young Adult Social well-being and Health longitudinal study draws on life-course models to understand ethnic differences in health. A key hypothesis relates to the role of psychosocial factors in nurturing the health and well-being of ethnic minorities growing up in the UK. We report the effects of culturally patterned exposures in childhood. Methods: In 2002/2003, 6643 11–13 year olds in London, ~80 % ethnic minorities, participated in the baseline survey. In 2005/2006, 4782 were followed-up. In 2012–2014, 665 took part in a pilot follow-up aged 21–23 years, including 42 qualitative interviews. Measures of socioeconomic and psychosocial factors and health were collected. Results: Ethnic minority adolescents reported better mental health than White British, despite more adversity (e.g. economic disadvantage, racism). It is unclear what explains this resilience but findings support a role for cultural factors. Racism was an adverse influence on mental health, while family care and connectedness, religious involvement and ethnic diversity of friendships were protective. While mental health resilience was a feature throughout adolescence, a less positive picture emerged for cardio-respiratory health. Both, mental health and cultural factors played a role. These patterns largely endured in early 20s with family support reducing stressful transitions to adulthood. Education levels, however, signal potential for socio-economic parity across ethnic groups
Asthma in Black African, Black Caribbean and South Asian adolescents in the MRC DASH study: a cross sectional analysis
Extent: 7p.Background: Ethnic differences in the prevalence of asthma among children in the UK are under-researched. We aimed to determine the ethnic differences in the prevalence of asthma and atopic asthma in children from the main UK ethnic groups, and whether differences are associated with differential distributions in social and psychosocial risk factors. Methods: 6,643 pupils aged 11-13 years, 80% ethnic minorities. Outcomes were asthma/wheeze with (atopic) and without hay fever/eczema. Risk factors examined were family history of asthma, length of residence in the UK, socioeconomic disadvantage, tobacco exposure, psychological well-being, and body mass index (BMI). Results: There was a pattern of lower prevalence of asthma in Black African boys and girls, and Indian and Bangladeshi girls compared to White UK. The overall prevalence was higher in Mixed Black Caribbean/White boys, with more atopic asthma in Black Caribbean boys and Mixed Black Caribbean/White boys due to more hayfever. Poor psychological well-being and family history of asthma were associated with an increased risk of asthma within each ethnic group. UK residence for ≤ 5 years was protective for Black Caribbeans and Black Africans. Increased BMI was associated with an increased reporting of asthma for Black Africans. Adjustments for all variables did not remove the excess asthma reported by Black Caribbean boys (atopic) or Mixed Black Caribbean/White boys. Conclusion: The protective effect of being born abroad accounted for ethnic differences in some groups, signalling a role for socio-environmental factors in patterning ethnic differences in asthma in adolescence.Melissa J Whitrow and Seeromanie Hardin
Towards a quantum universe
In this short review we study the state of the art of the great problems in
cosmology and their interrelationships. The reconciliation of these problems
passes undoubtedly through the idea of a quantum universe.Comment: 7 pages, Accepted for publication in Astrophysics & Space Scienc
Percentiles of fasting serum insulin, glucose, HbA1c and HOMA-IR in pre-pubertal normal weight European children from the IDEFICS cohort
OBJECTIVES: The aim of this study is to present age-and sex-specific reference values of insulin, glucose, glycosylated haemoglobin (HbA1c) and the homeostasis model assessment to quantify insulin resistance (HOMA-IR) for pre-pubertal children.
METHODS: The reference population consists of 7074 normal weight 3- to 10.9-year-old pre-pubertal children from eight European countries who participated in at least one wave of the IDEFICS ('identification and prevention of dietary-and lifestyle-induced health effects in children and infants') surveys (2007-2010) and for whom standardised laboratory measurements were obtained. Percentile curves of insulin (measured by an electrochemiluminescence immunoassay), glucose, HbA1c and HOMA-IR were calculated as a function of age stratified by sex using the general additive model for location scale and shape (GAMLSS) method.
RESULTS: Levels of insulin, fasting glucose and HOMA-IR continuously show an increasing trend with age, whereas HbA1c shows an upward trend only beyond the age of 8 years. Insulin and HOMA-IR values are higher in girls of all age groups, whereas glucose values are slightly higher in boys. Median serum levels of insulin range from 17.4 and 13.2 pmol l(-1) in 3-< 3.5-year-old girls and boys, respectively, to 53.5 and 43.0 pmol l(-1) in 10.5-< 11-year-old girls and boys. Median values of glucose are 4.3 and 4.5 mmol l(-1) in the youngest age group and 49.3 and 50.6 mmol l(-1) in the oldest girls and boys. For HOMA-IR, median values range from 0.5 and 0.4 in 3-< 3.5-year-old girls and boys to 1.7 and 1.4 in 10.5-< 11-year-old girls and boys, respectively.
CONCLUSIONS: Our study provides the first standardised reference values for an international European children's population and provides the, up to now, largest data set of healthy pre-pubertal children to model reference percentiles for markers of insulin resistance. Our cohort shows higher values of Hb1Ac as compared with a single Swedish study while our percentiles for the other glucose metabolic markers are in good accordance with previous studies
Is American Public Administration Detached From Historical Context?: On the Nature of Time and the Need to Understand It in Government and Its Study
The study of public administration pays little attention to history. Most publications are focused on current problems (the present) and desired solutions (the future) and are concerned mainly with organizational structure (a substantive issue) and output targets (an aggregative issue that involves measures of both individual performance and organizational productivity/services). There is much less consideration of how public administration (i.e., organization, policy, the study, etc.) unfolds over time. History, and so administrative history, is regarded as a “past” that can be recorded for its own sake but has little relevance to contemporary challenges. This view of history is the product of a diminished and anemic sense of time, resulting from organizing the past as a series of events that inexorably lead up to the present in a linear fashion. To improve the understanding of government’s role and position in society, public administration scholarship needs to reacquaint itself with the nature of time.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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