4,473 research outputs found
Development of improved adhesives for use at cryogenic temperatures to minus423 deg F Final summary report, 11 Jul. 1963 - 31 Aug. 1965
Improved polyurethane and epoxy resins for use as adhesives at cryogenic temperature
Phenolphthalein-containing laxative use in relation to adenomatous colorectal polyps in three studies.
Phenolphthalein, the active ingredient in many laxatives, was recently found to be a carcinogen in animal models. Human data suggest a laxative-colon cancer association, but few data specifically address the effects of phenolthalein-containing laxatives. We examined use of phenolphtalein-containing laxatives in relation to occurrence of adenomatous colorectal polyps in data from three case-control studies. The study conducted in Los Angeles, California (1991-1993), and the two studies conducted in North Carolina (1988-1990 and 1992-1995) altogether included 866 cases and 1,066 controls. The prevalence of using phenolphthalein-containing laxatives at least once a week in the recent past, however, was less than 5% among these subjects. The multivariate-adjusted odds ratios associated with recent use of phenolphthalein-containing laxatives once a week or more were 1.8 -95% confidence interval (CI), 0.5-6.2] in Los Angeles, 1.0 (CI, 0.4-2.2) in North Carolina (1988-1990), and 1.1 (CI, 0.2-5.7) in North Carolina (1992-1995). For use of other types of laxatives, the corresponding odds ratios were 1.3 (CI, 0.9-1.9) in Los Angeles, 1.0 (CI, 0.5-1.7) in North Carolina (1988-1990), and 0.9 (CI, 0.4-1.8) in North Carolina (1992-1995). Although the low prevalence of frequent use made for relatively wide confidence intervals, overall these data suggest that use of phenolphthalein-containing laxatives does not increase risk of adenomatous colorectal polyps
Evaluation of positive G sub Z tolerance following simulated weightlessness (bedrest)
The magnitude of physiologic changes which are known to occur in human subjects exposed to varying levels of + G sub Z acceleration following bed rest simulation of weightlessness was studied. Bed rest effects were documented by fluid and electrolyte balance studies, maximal exercise capability, 70 deg passive tilt and lower body negative pressure tests and the ability to endure randomly prescribed acceleration profiles of +2G sub Z, +3G sub Z, and +4G sub Z. Six healthy male volunteers were studied during two weeks of bed rest after adequate control observations, followed by two weeks of recovery, followed by a second two-week period of bed rest at which time an Air Force cutaway anti-G suit was used to determine its effectiveness as a countermeasure for observed cardiovascular changes during acceleration. Results showed uniform and significant changes in all measured parameters as a consequence of bed rest including a reduced ability to tolerate +G sub Z acceleration. The use of anti-G suits significantly improved subject tolerance to all G exposures and returned measured parameters such as heart rate and blood pressure towards or to pre-bed-rest (control) values in four of the six cases
Bringing Salary Transparency to the World: Computing Robust Compensation Insights via LinkedIn Salary
The recently launched LinkedIn Salary product has been designed with the goal
of providing compensation insights to the world's professionals and thereby
helping them optimize their earning potential. We describe the overall design
and architecture of the statistical modeling system underlying this product. We
focus on the unique data mining challenges while designing and implementing the
system, and describe the modeling components such as Bayesian hierarchical
smoothing that help to compute and present robust compensation insights to
users. We report on extensive evaluation with nearly one year of de-identified
compensation data collected from over one million LinkedIn users, thereby
demonstrating the efficacy of the statistical models. We also highlight the
lessons learned through the deployment of our system at LinkedIn.Comment: Conference information: ACM International Conference on Information
and Knowledge Management (CIKM 2017
Correlated quantum percolation in the lowest Landau level
Our understanding of localization in the integer quantum Hall effect is
informed by a combination of semi-classical models and percolation theory.
Motivated by the effect of correlations on classical percolation we study
numerically electron localization in the lowest Landau level in the presence of
a power-law correlated disorder potential. Careful comparisons between
classical and quantum dynamics suggest that the extended Harris criterion is
applicable in the quantum case. This leads to a prediction of new localization
quantum critical points in integer quantum Hall systems with power-law
correlated disorder potentials. We demonstrate the stability of these critical
points to addition of competing short-range disorder potentials, and discuss
possible experimental realizations.Comment: 15 pages, 12 figure
A study of psychiatrists’ concepts of mental illness
Background: There are multiple models of mental illness that inform professional and lay understanding. Few studies have formally investigated psychiatrists' attitudes. We aimed to measure how a group of trainee psychiatrists understand familiar mental illnesses in terms of propositions drawn from different models.
Method: We used a questionnaire study of a sample of trainees from South London and Maudsley National Health Service (NHS) Foundation Trust designed to assess attitudes across eight models of mental illness (e.g. biological, psychodynamic) and four psychiatric disorders. Methods for analysing repeated measures and a principal components analysis (PCA) were used.
Results: No one model was endorsed by all respondents. Model endorsement varied with disorder. Attitudes to schizophrenia were expressed with the greatest conviction across models. Overall, the ‘biological’ model was the most strongly endorsed. The first three components of the PCA (interpreted as dimensions around which psychiatrists, as a group, understand mental illness) accounted for 56% of the variance. Each main component was classified in terms of its distinctive combination of statements from different models: PC1 33% biological versus non-biological; PC2 12% ‘eclectic’ (combining biological, behavioural, cognitive and spiritual models); and PC3 10% psychodynamic versus sociological.
Conclusions: Trainee psychiatrists are most committed to the biological model for schizophrenia, but in general are not exclusively committed to any one model. As a group, they organize their attitudes towards mental illness in terms of a biological/non-biological contrast, an ‘eclectic’ view and a psychodynamic/sociological contrast. Better understanding of how professional group membership influences attitudes may facilitate better multidisciplinary working
Management of Renal Cell Carcinoma: Evaluation of Renal Masses by Modem Radiological Techniques
The utilty of ultrasound and computed tomography is compared to angiography and that of nephrotomography in the study of renal masses. Ultrasound and computed tomography, noninvasive methods, are replacing nephrotomography and, in some cases, angiograph
Military spending and economic growth in China: a regime-switching analysis
This article has been made available through the Brunel Open Access Publishing Fund.This article investigates the impact of military spending changes on economic growth in China over the period 1953 to 2010. Using two-state Markov-switching specifications, the results suggest that the relationship between military spending changes and economic growth is state dependent. Specifically, the results show that military spending changes affect the economic growth negatively during a slower growth-higher variance state, while positively within a faster growth-lower variance one. It is also demonstrated that military spending changes contain information about the growth transition probabilities. As a policy tool, the results indicate that increases in military spending can be detrimental to growth during slower growth-higher growth volatility periods. © 2014 © 2014 The Author(s). Published by Taylor & Francis
Kondo regime in triangular arrangements of quantum dots: Molecular orbitals, interference and contact effects
Transport properties of an interacting triple quantum dot system coupled to
three leads in a triangular geometry has been studied in the Kondo regime.
Applying mean-field finite-U slave boson and embedded cluster approximations to
the calculation of transport properties unveils a set of rich features
associated to the high symmetry of this system. Results using both calculation
techniques yield excellent overall agreement and provide additional insights
into the physical behavior of this interesting geometry. In the case when just
two current leads are connected to the three-dot system, interference effects
between degenerate molecular orbitals are found to strongly affect the overall
conductance. An S=1 Kondo effect is also shown to appear for the perfect
equilateral triangle symmetry. The introduction of a third current lead results
in an `amplitude leakage' phenomenon, akin to that appearing in beam splitters,
which alters the interference effects and the overall conductance through the
system.Comment: 14 pages, 9 figures, submitted to PR
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