581 research outputs found
Software control program for 25 kW breadboard testing
A data acquisition software program developed to operate in conjunction with the automated control system of the 25 kW PM Electric Power System Breadboard Test facility is described. The proram provides limited interactive control of the breadboard test while acquiring data and monitoring parameters, allowing unattended continuous operation. The breadboard test facility has two positions for operating separate configurations. The main variable in each test setup is the high voltage Ni-Cd battery
Effect of polar intermolecular interactions on the elastic constants of bent-core nematics and the origin of the twist-bend phase
Abstract.: A molecular theory of both elastic constants and the flexoelectric coefficients of bent-core nematic liquid crystals has been developed taking into account dipole-dipole interactions as well as polar interactions determined by the bent molecular shape. It has been shown that if polar interactions are neglected, the elastic constants are increasing monotonically with the decreasing temperature. On the other hand, dipolar interactions between bent-core molecules may result in a dramatic increase of the bend flexocoefficient. As a result, the flexoelectric contribution to the bend elastic constant increases significantly, and the bend elastic constant appears to be very small throughout the nematic range and may vanish at a certain temperature. This temperature may then be identified as a temperature of the elastic instability of the bent-core nematic phase which induces a transition into the modulated phases with bend deformations like recently reported twist-bend phase. The temperature variation of the elastic constants is qualitatively similar to the typical experimental data for bent-core nematics. Graphical abstract: [Figure not available: see fulltext.
Hubble space telescope six-battery test bed
A test bed for a large space power system breadboard for the Hubble Space Telescope (HST) was designed and built to test the system under simulated orbital conditions. A discussion of the data acquisition and control subsystems designed to provide for continuous 24 hr per day operation and a general overview of the test bed is presented. The data acquisition and control subsystems provided the necessary monitoring and protection to assure safe shutdown with protection of test articles in case of loss of power or equipment failure over the life of the test (up to 5 years)
SCORE performance in Central and Eastern Europe and former Soviet Union: MONICA and HAPIEE results
Aims: The Systematic COronary Risk Evaluation (SCORE) scale assesses 10 year risk of fatal atherosclerotic cardiovascular disease (CVD), based on conventional risk factors. The high-risk SCORE version is recommended for Central and Eastern Europe and former Soviet Union (CEE/FSU), but its performance has never been systematically assessed in the region. We evaluated SCORE performance in two sets of population-based CEE/FSU cohorts.
Methods and results: The cohorts based on the World Health Organization MONitoring of trends and determinants in CArdiovascular disease (MONICA) surveys in the Czech Republic, Poland (Warsaw and Tarnobrzeg), Lithuania (Kaunas), and Russia (Novosibirsk) were followed from the mid-1980s. The Health, Alcohol, and Psychosocial factors in Eastern Europe (HAPIEE) study follows Czech, Polish (Krakow), and Russian (Novosibirsk) cohorts from 2002–05. In Cox regression analyses, the high-risk SCORE ≥5% at baseline significantly predicted CVD mortality in both MONICA [n = 15 027; hazard ratios (HR), 1.7–6.3] and HAPIEE (n = 20 517; HR, 2.6–10.5) samples. While SCORE calibration was good in most MONICA samples (predicted and observed mortality were close), the risk was underestimated in Russia. In HAPIEE, the high-risk SCORE overpredicted the estimated 10 year mortality for Czech and Polish samples and adequately predicted it for Russia. SCORE discrimination was satisfactory in both MONICA and HAPIEE.
Conclusion: The high-risk SCORE underestimated the fatal CVD risk in Russian MONICA but performed well in most MONICA samples and Russian HAPIEE. This SCORE version might overestimate the risk in contemporary Czech and Polish populations
Socio-economic status over the life-course and depressive symptoms in men and women in Eastern Europe
Objective: Research into social inequalities in depression has studied western populations but data from non-western countries are sparse. In this paper, we investigate the extent of social inequalities in depression in Eastern Europe, the relative importance of social position at different points of the life-course, and whether social patterning of depression differs between men and women.Method: A cross-sectional study examined 12,053 men and 13,582 women in Russia, Poland and the Czech Republic. Depressive symptoms (16 or above on the CESD-20) were examined in relation to socio-economic circumstances at three phases of the life-course: childhood (household amenities and father's education); own education; current circumstances (financial difficulties and possession of household items).Results: Pronounced social differences in depression exist in men and women throughout Eastern Europe. Depression was largely influenced by current circumstances rather than by early life or education, with effects stronger in Poland and Russia. Odds ratios in men for current disadvantage were 3.16 [95% CI: 2.57-3.89], 3.16 [2.74-3.64] and 2.17 [1.80-2.63] in Russia, Poland and the Czech Republic respectively. Social variables did not explain the female excess in depression, which varied from 2.91 [2.58-3.27] in Russia to 1.90 [1.74-2.08] in Poland. Men were more affected by adult disadvantage than women, leading to narrower sex differentials in the presence of disadvantage.Limitations: Cross-sectional data with recall of childhood conditions were used.Conclusion: Current social circumstances are the strongest influence on increased depressive symptoms in countries which have recently experienced social changes. (C) 2007 Elsevier B.V. All rights reserved
Bowel and Bladder-Control Anxiety: A Preliminary Description of a Viscerally-Centred Phobic Syndrome
Background: People with anxiety disorders occasionally report fears about losing control of basic bodily functions in public. These anxieties often occur in the absence of physical disorder and have previously been recognized as “obsessive” anxieties reflecting a preoccupation with loss of bowel/bladder control. Motivated by our observations of the non-trivial occurrence of such anxieties in our clinical practice we sought to fill a gap in the current understanding of “bowel/bladder-control anxieties”. Method: Eligible participants completed an internet survey. Results: Bowel/bladder-control anxieties (n=140) tended to emerge in the mid to late 20s and were associated with high levels of avoidance and functional impairment. There was a high prevalence of panic attacks (78%); these were especially prevalent among those with bowel-control anxiety. Of those with panic attacks, 62% indicated that their main concern was being incontinent during a panic attack. Significantly, a proportion of respondents (~16%) reported actually being incontinent during a panic attack. Seventy percent of participants reported intrusive imagery related to loss of bowel/bladder control. Intrusion-related distress was correlated with agoraphobic avoidance and general role impairment. Some differences were noted between those with predominantly bowel-, predominantly bladder- and those with both bowel and bladder-control anxieties. Conclusion: This preliminary characterization indicates that even in a non-treatment seeking community sample, bowel/bladder-control anxieties are associated with high levels of distress and impairment. Further careful characterization of these anxieties will clarify their phenomenology and help us develop or modify treatment protocols in a way that takes account of any special characteristics of such viscerally-centred phobic syndromes
Coffee consumption and mortality in three Eastern European countries: results from the HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe) study
OBJECTIVE: To test the association between coffee consumption and risk of all-cause, CVD and cancer death in a European cohort. DESIGN: Prospective cohort study. Cox proportional hazards models with adjustment for potential confounders to estimate multivariable hazard ratios (HR) and 95 % CI were used. SETTING: Czech Republic, Russia and Poland. SUBJECTS: A total of 28561 individuals followed for 6·1 years. RESULTS: A total of 2121 deaths (43·1 % CVD and 35·7 % cancer mortality) occurred during the follow-up. Consumption of 3-4 cups coffee/d was associated with lower mortality risk in men (HR=0·83; 95 % CI 0·71, 0·99) and women (HR=0·63; 95 % CI 0·47, 0·84), while further intake showed non-significant reduced risk estimates (HR=0·71; 95 % CI 0·49, 1·04 and HR=0·51; 95 % CI 0·24, 1·10 in men and women, respectively). Decreased risk of CVD mortality was also found in men (HR=0·71; 95 % CI 0·54, 0·93) for consumption of 3-4 cups coffee/d. Stratified analysis revealed that consumption of a similar amount of coffee was associated with decreased risk of all-cause (HR=0·61; 95 % CI 0·43, 0·87) and cancer mortality (HR=0·59; 95 % CI 0·35, 0·99) in non-smoking women and decreased risk of all-cause mortality for >4 cups coffee/d in men with no/moderate alcohol intake. CONCLUSIONS: Coffee consumption was associated with decreased risk of mortality. The protective effect was even stronger when stratification by smoking status and alcohol intake was performed
Dietary polyphenol intake and risk of hypertension in the Polish arm of the HAPIEE study
PURPOSE: Dietary polyphenols have been studied for their potential effects on metabolic disorders, but studies on risk of hypertension are scarce. This study aimed to test the association between total and individual classes of dietary polyphenols and incidence of hypertension in the Polish arm of the Health, Alcohol and Psychosocial factors In Eastern Europe (HAPIEE) study. METHODS: A total of 2725 participants free of hypertension at baseline were tested for blood pressure or taking hypertensive medication within the last 2 weeks at 2-4-year follow-up visit. A 148-item food frequency questionnaire and the Phenol-Explorer database were used to estimate dietary polyphenol intake. Odds ratios (ORs) and 95% confidence intervals (CIs) of hypertension comparing the various categories of exposure (total and individual classes of polyphenol intake) with the lowest one (reference category) were calculated by performing age- and energy-adjusted and multivariate-adjusted logistic regression models. RESULTS: During follow-up, 1735 incident cases of hypertension occurred. The highest quartile of total polyphenol intake was associated with 31% decreased risk of hypertension compared with the lowest intake (OR 0.69, 95% CI 0.48, 0.98) in women. There was no significant association in men. Among main classes of polyphenols, flavonoids and phenolic acids were independent contributors to this association. The analysis of individual subclasses of polyphenol revealed that, among phenolic acids, hydroxycynnamic acids were independently associated to lower odds of hypertension (OR 0.66, 95% CI 0.47, 0.93), while among flavonoids, most of the association was driven by flavanols (OR 0.56, 95% CI 0.36, 0.87). CONCLUSION: Certain classes of dietary polyphenols were associated with lower risk of hypertension, but potential differences between men and women should be further investigated
Dietary polyphenol intake and risk of type 2 diabetes in the Polish arm of the Health, Alcohol and Psychosocial factors in Eastern Europe (HAPIEE) study
This study aimed to test the association between dietary content of total and individual classes of polyphenols and incident cases of type 2 diabetes in Polish adults participating to the Health, Alcohol and Psychosocial factors In Eastern Europe study. At baseline, diet by 148-item FFQ and health information were collected from 5806 participants free of diabetes. Self-reported incident type 2 diabetes was ascertained at 2-4-year follow-up visit. OR and 95 % CI of type 2 diabetes comparing the various categories of polyphenol intake to the lowest one (reference category) and as 1 sd increase modelled as continuous variable were calculated by performing age-, energy-, and multivariate-adjusted logistic regression models. During the follow-up, 456 incident cases of type 2 diabetes occurred. When comparing extreme quartiles, intake of total polyphenol was inversely associated with the risk of type 2 diabetes (OR 0·43; 95 % CI 0·30, 0·61); 1 sd increase was associated with a reduced risk of diabetes (OR 0·68; 95 % CI 0·59, 0·79). Among the main classes of polyphenols, flavonoids, phenolic acids, and stilbenes were independent contributors to this association. Both subclasses of phenolic acids were associated with decreased risk of type 2 diabetes, whereas among subclasses of flavonoids, high intake of flavanols, flavanones, flavones and anthocyanins was significantly associated with decreased risk of type 2 diabetes. Total dietary polyphenols and some classes of dietary polyphenols were associated with lower risk of type 2 diabetes
Teacher-Student chain for efficient semi-supervised histology image classification
Deep learning shows great potential for the domain of digital pathology. An
automated digital pathology system could serve as a second reader, perform
initial triage in large screening studies, or assist in reporting. However, it
is expensive to exhaustively annotate large histology image databases, since
medical specialists are a scarce resource. In this paper, we apply the
semi-supervised teacher-student knowledge distillation technique proposed by
Yalniz et al. (2019) to the task of quantifying prognostic features in
colorectal cancer. We obtain accuracy improvements through extending this
approach to a chain of students, where each student's predictions are used to
train the next student i.e. the student becomes the teacher. Using the chain
approach, and only 0.5% labelled data (the remaining 99.5% in the unlabelled
pool), we match the accuracy of training on 100% labelled data. At lower
percentages of labelled data, similar gains in accuracy are seen, allowing some
recovery of accuracy even from a poor initial choice of labelled training set.
In conclusion, this approach shows promise for reducing the annotation burden,
thus increasing the affordability of automated digital pathology systems.Comment: AI for Affordable Healthcare (AI4AH) workshop at ICLR 202
- …