1,624 research outputs found
A Random Point Field related to Bose-Einstein Condensation
The random point field which describes the position distribution of the
system of ideal boson gas in a state of Bose-Einstein condensation is obtained
through the thermodynamic limit. The resulting point field is given by
convolution of two independent point fields: the so called boson process whose
generating functional is represented by inverse of the Fredholm determinant for
an operator related to the heat operator and the point field whose generating
functional is represented by a resolvent of the operator. The construction of
the latter point field in an abstract formulation is also given.Comment: 21 page
Mortality study of 18 000 patients treated with omeprazole.
Background: The long term safety of potent gastric acid suppressive therapy has yet to be established.
Method: General practice record review at a median interval of 26 months followed by retrieval of details of all deaths within four years using the UK National Health Service Central Registers in 17 936 patients prescribed omeprazole in 1993â1995. Death rates were compared with general population rates.
Results: Records of 17 489 patients (97.5%) were examined. A total of 12 703 patients received further scripts for antisecretory drugs, 8097 for omeprazole only (65.6%): 3097 patients have died. All cause mortality was higher in the first year (observed/expected (O/E) 1.44 (95% confidence intervals (CI) 1.34â1.55); p<0.0001) but had fallen to population expectation by the fourth year. There were significant mortality increases in the first year, falling to or below population expectation by the fourth year, for deaths ascribed to neoplasms (1.82 (95% CI 1.58â2.08); p<0.0001), circulatory diseases (1.27 (95% CI 1.13â1.43); p<0.0001), and respiratory diseases (1.37 (95% CI 1.12â1.64); p<0.001). Increased mortality ascribed to digestive diseases (2.56 (95% CI 1.87â3.43); p<0.0001) persisted, although reduced. Increased mortality rates for cancers of the stomach (4.06 (95% CI 2.60â6.04); p<0.0001), colon and rectum (1.40 (95% CI 0.84â2.18); p=0.075), and trachea, bronchus, and lung (1.64 (95% CI 1.19â2.19); p<0.01) seen in the first year had disappeared by the fourth year but that for cancer of the oesophagus had not (O/E 7.35 (95% CI 5.20â10.09) (p<0.0001) in year 1; 2.88 (95% CI 1.62â4.79) (p<0.001) in year 4). Forty of 78 patients dying of oesophageal cancer had the disease present at registration. Twenty seven of those remaining cases had clinical evidence of Barrettâs disease, stricture, ulcer, or oesophagitis at registration (O/E 3.30 (95% CI 2.17â4.80)). Six deaths occurred in patients with hiatal hernia or reflux only (O/E 1.02 (95% CI 0.37â2.22)) and five in patients without oesophageal disease (O/E 0.77 (95% CI 0.25â1.80)). No relationships were detected with numbers of omeprazole scripts received.
Conclusions: Increases in mortality associated with treatment are due to pre- existing illness, including pre-existing severe oesophageal disease. There was no evidence of an increased risk of oesophageal adenocarcinoma in those without oesophageal mucosal damage recorded at registration
Physical Activity, Sedentary Behavior, and Retirement: The Multi-Ethnic Study of Atherosclerosis
Introduction: Physical activity and sedentary behavior are major risk factors for chronic disease. These behaviors may change at retirement, with implications for health in later life. The study objective was to describe longitudinal patterns of moderate to vigorous and domain-specific physical activity and TV watching by retirement status. Methods: Participants in the Multi-Ethnic Study of Atherosclerosis (n=6,814) were recruited from six U.S. communities and were aged 45â84 years at baseline. Retirement status and frequency and duration of domain-specific physical activity (recreational walking, transport walking, non-walking leisure activity, caregiving, household, occupational/volunteer) and TV watching were self-reported at four study exams (2000 to 2012). Fixed effect linear regression models were used to describe longitudinal patterns in physical activity and TV watching by retirement status overall and stratified by socioeconomic position. Analyses were conducted in 2017. Results: Of 4,091 Multi-Ethnic Study of Atherosclerosis participants not retired at baseline, 1,012 (25%) retired during a median of 9 years follow-up. Retirement was associated with a 10% decrease (95% CI= â15%, â5%) in moderate to vigorous physical activity and increases of 13% to 29% in recreational walking, household activity, and TV watching. Among people of low socioeconomic position, the magnitude of association was larger for moderate to vigorous physical activity. Among people of high socioeconomic position, the magnitude of association was larger for non-walking leisure and household activity. Conclusions: The retirement transition was associated with changes in physical activity and TV watching. To inform intervention development, future research is needed on the determinants of behavior change after retirement, particularly among individuals of low socioeconomic position. Š 2018 American Journal of Preventive Medicin
Specializing Interpreters using Offline Partial Deduction
We present the latest version of the Logen partial evaluation system for logic programs. In particular we present new binding-types, and show how they can be used to effectively specialise a wide variety of interpreters.We show how to achieve Jones-optimality in a systematic way for several interpreters. Finally, we present and specialise a non-trivial interpreter for a small functional programming language. Experimental results are also presented, highlighting that the Logen system can be a good basis for generating compilers for high-level languages
The prevalence of, and factors associated with, paying for sex among men resident in Britain: findings from the third national survey of sexual attitudes and lifestyles (Natsal-3)
Objectives Men who pay for sex (MPS) are considered a bridging population for sexually transmitted infections (STI). However, the extent, characteristics and role of MPS in transmission is poorly understood. We investigate these questions using data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).
Methods We performed complex survey analyses of data from 6293 men aged 16â74â
years resident in Britain who completed Natsal-3, a probability sample survey undertaken during 2010â2012, using computer-assisted personal interviewing and computer-assisted self-interview.
Results 11.0% (95% CI10.1% to 11.9%) of all men reported ever paying for sex. Among MPS, 18.4% (95% CI 18.2% to 18.7%) of their lifetime sexual partners were paid. 3.6% (95% CI 3.1% to 4.2%) of men had paid for sex in the past 5â
years. Partners of MPS constitute 14.7% of all reported partners and MPS report 15.6% of all reported STI diagnoses in the past 5â
years. Paying for sex in the past 5â
years was strongly associated with reporting larger numbers of sexual partners (adjusted OR, AOR for 5+ partners, past 5 years, 31.50, 95% CI 18.69 to 53.09). After adjusting for partner numbers, paying for sex remained strongly associated with reporting new foreign partners outside the UK (AOR 7.96; 95% CI 4.97 to 12.73) and STI diagnosis/es (AOR 2.34; 95% CI 1.44 to 3.81), all in the past 5 years. Among men ever paying for sex, 62.6% (95% CI 58.3% to 66.8%) reported paying for sex outside the UK, most often in Europe and Asia.
Conclusions MPS in Britain remain at greater risk of STI acquisition and onward transmission than men who do not. They report high numbers of partners, but the minority are paid partners. They are an important core group in STI transmission
Unification through extra dimensions at two loops
The presence of an extra dimension of size R\equiv M_c^{-1} introduces
corrections of order (\mu/M_c)\alpha to the gauge and Yukawa couplings and
accelerates their running at scales \mu larger than M_c. This could result in a
grand unification scale M_X\approx 20 M_c. We study the corrections at the
two-loop level. We find corrections of order (\mu/M_c)\alpha^2 for the gauge
couplings and of order (\mu/M_c)^2\alpha^2 for the Yukawa couplings. Therefore,
in the Yukawa sector one and two-loop contributions can be of the same order
below M_X. We show that in the usual scenarios the dominant gauge and Yukawa
couplings are decreasing functions of the scale, in such a way that
(\mu/M_c)\alpha becomes approximately constant and two-loop contributions
introduce just a 30% correction which does not increase with the scale.Comment: 14 pages, added references, corrected typo
Biogeochemical processes in the active layer and permafrost of a high Arctic fjord valley
Warming of ground is causing microbial decomposition of previously frozen sedimentary organic carbon in Arctic permafrost. However, the heterogeneity of the permafrost landscape and its hydrological processes result in different biogeochemical processes across relatively small scales, with implications for predicting the timing and magnitude of permafrost carbon emissions. The biogeochemical processes of iron- and sulfate-reduction produce carbon dioxide and suppress methanogenesis. Hence, in this study, the biogeochemical processes occurring in the active layer and permafrost of a high Arctic fjord valley in Svalbard are identified from the geochemical and stable isotope analysis of aqueous and particulate fractions in sediment cores collected from ice-wedge polygons with contrasting water content. In the drier polygons, only a small concentration of organic carbon (<5.40 dry weight%) has accumulated. Sediment cores from these drier polygons have aqueous and solid phase chemistries that imply sulfide oxidation coupled to carbonate and silicate dissolution, leading to high concentrations of aqueous iron and sulfate in the pore water profiles. These results are corroborated by δ34S and δ18O values of sulfate in active layer pore waters, which indicate the oxidative weathering of sedimentary pyrite utilising either oxygen or ferric iron as oxidising agents. Conversely, in the sediments of the consistently water-saturated polygons, which contain a high content of organic carbon (up to 45 dry weight%), the formation of pyrite and siderite occurred via the reduction of iron and sulfate. δ34S and δ18O values of sulfate in active layer pore waters from these water-saturated polygons display a strong positive correlation (R2 = 0.98), supporting the importance of sulfate reduction in removing sulfate from the pore water. The significant contrast in the dominant biogeochemical processes between the water-saturated and drier polygons indicates that small-scale hydrological variability between polygons induces large differences in the concentration of organic carbon and in the cycling of iron and sulfur, with ramifications for the decomposition pathway of organic carbon in permafrost environments
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Libraries and open society; Popper, Soros and digital information
This paper examines the role of libraries and information services, in promoting the âopen societyâ espoused by Karl Popper and George Soros. After a brief discussion of the nature of an âopen societyâ, the paper covers the role played by provision of knowledge and information, of new technology, particularly the Internet, and of critical thinking and digital literacy in the development of this form of society. Conclusions are drawn for the role of libraries and librarians, with seven general principles suggested:
⢠provision of access to a wide variety of sources without ânegativeâ restriction or censorship
⢠provision of âpositiveâ guidance on sources, based on open and objective criteria
⢠a recognition that a âfree flow of informationâ though essential, is not sufficient
⢠a recognition that provision of factual information, while valuable, is not enough
⢠a need for a specific concern for the effect of new ICTs, and the Internet in particular
⢠promotion of critical thinking and digital literacy
⢠a need for explicit consideration of the ethical values of librarie
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