986 research outputs found
Comparison of Different Methods for Transverse Emittance Measurement and Recent Results from LEP
The knowledge of its position and angular transverse distributions is of utmost interest to assess the good behaviour of a beam within an accelerator. After a short reminder of beam "emittance" definitions, a review is made of various measurement techniques used so far both in single pass machines and colliders. Results of measurements made at CERN in the future LHC injection complex and in LEP are presented and discussed
Hypertension Prevalence Based on Blood Pressure Measurements on Two vs. One Visits: A Community-Based Screening Programme and a Narrative Review.
We assessed the difference in the prevalence of hypertension in community surveys when blood pressure (BP) was measured on two vs. one visits and its impact on hypertension awareness, treatment and control proportions. A community-based BP screening programme was conducted in public places in the Seychelles (619 adults) and BP was rechecked a few days later among untreated participants with high BP (≥140/90 mmHg). A narrative review of the literature on this question was also conducted. Only 64% of untreated participants with high BP still had high BP at the second visit. The prevalence of hypertension in the whole sample decreased by 13% (from 33.8% to 29.5%) when BP was measured on two vs. one visits. These results concurred with our findings in our narrative review based on 10 surveys. In conclusion, the prevalence of hypertension can be markedly overestimated in community surveys when BP is measured on two vs. one visits. The overestimation could be addressed by measuring BP on a second visit among untreated individuals with high BP or, possibly, by taking more readings at the first visit. These findings have relevance for clinical practice, policy and surveillance
Electronic Structure of the YH3 Phase from Angle-Resolved Photoemission Spectroscopy
Yttrium can be loaded with hydrogen up to high concentrations causing
dramatic structural and electronic changes of the host lattice. We report on
angle-resolved photoemission experiments of the Y trihydride phase. Most
importantly, we find the absence of metal d-bands at the Fermi level and a set
of flat, H-induced bands located at much higher binding energy than predicted,
indicating an increased electron affinity at H sites
Performance of different adiposity measures for predicting cardiovascular risk in adolescents.
This study aims to compare the performance of body mass index (BMI), waist circumference (WC), and waist-to-height-ratio (WHtR) to predict the presence of at least 3 main CV risk factors in US adolescents. A total of 3621 adolescents (boys: 49.9%) aged 12-17 years from the US National Health and Nutrition Examination Survey (1999-2012) were included in this study. Measured CV risk factors included systolic/diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and fasting plasma glucose. The AUC of BMI-z score, WC-z score and WHtR-z score to predict at least three CV risk factors were similar (~0.85), irrespective of criteria used to define abnormal levels of CV risk factors. A 1-SD increase in any of three indices to predict CV risk was also similar for the three adiposity scores. For instance, a 1-SD increase risk in BMI-z score, WC-z score and WHtR-z score was 3.32 (95%CI 2.53-4.36), 3.43 (95%CI 2.64-4.46), and 3.45 (95%CI 2.64-4.52), respectively, in the total population using the International Diabetes Federation definition. In addition, the most efficient WHtR cut-off for screening CV risk was ~0.50 in US adolescents. In summary, BMI, WC and WHtR performed similarly well to predict the presence of at least 3 main CV risk factors among US adolescents
Screening for cardiovascular disease risk factors beginning in childhood
Cardiovascular diseases (CVD) are the leading cause of death worldwide. Individual detection and intervention on CVD risk factors and behaviors throughout childhood and adolescence has been advocated as a strategy to reduce CVD risk in adulthood. The U.S. National Heart, Lung, and Blood Institute (NHLBI) has recently recommended universal screening of several risk factors in children and adolescents, at odds with several recommendations of the U.S. Services Task Force and of the U.K. National Screening committee. In the current review, we discuss the goals of screening for CVD risk factors (elevated blood pressure, abnormal blood lipids, diabetes) and behaviors (smoking) in children and appraise critically various screening recommendations. Our review suggests that there is no compelling evidence to recommend universal screening for elevated blood pressure, abnormal blood lipids, abnormal blood glucose, or smoking in children and adolescents. Targeted screening of these risk factors could be useful but specific screening strategies have to be evaluated. Research is needed to identify target populations, screening frequency, intervention, and follow-up. Meanwhile, efforts should rather focus on the primordial prevention of CVD risk factors and at maintaining a lifelong ideal cardiovascular health through environmental, policy, and educational approaches
Screening for cardiovascular disease risk factors beginning in childhood
Cardiovascular diseases (CVD) are the leading cause of death worldwide. Individual detection and intervention on CVD risk factors and behaviors throughout childhood and adolescence has been advocated as a strategy to reduce CVD risk in adulthood. The U.S. National Heart, Lung, and Blood Institute (NHLBI) has recently recommended universal screening of several risk factors in children and adolescents, at odds with several recommendations of the U.S. Services Task Force and of the U.K. National Screening committee. In the current review, we discuss the goals of screening for CVD risk factors (elevated blood pressure, abnormal blood lipids, diabetes) and behaviors (smoking) in children and appraise critically various screening recommendations. Our review suggests that there is no compelling evidence to recommend universal screening for elevated blood pressure, abnormal blood lipids, abnormal blood glucose, or smoking in children and adolescents. Targeted screening of these risk factors could be useful but specific screening strategies have to be evaluated. Research is needed to identify target populations, screening frequency, intervention, and follow-up. Meanwhile, efforts should rather focus on the primordial prevention of CVD risk factors and at maintaining a lifelong ideal cardiovascular health through environmental, policy, and educational approaches
Rapid brain discrimination of sounds of objects.
Electrical neuroimaging in humans identified the speed and spatiotemporal brain mechanism whereby sounds of living and man-made objects are discriminated. Subjects performed an "oddball" target detection task, selectively responding to sounds of either living or man-made objects on alternating blocks, which were controlled for in their spectrogram and harmonics-to-noise ratios between categories. Analyses were conducted on 64-channel auditory evoked potentials (AEPs) from nontarget trials. Comparing responses to sounds of living versus man-made objects, these analyses tested for modulations in local AEP waveforms, global response strength, and the topography of the electric field at the scalp. In addition, the local autoregressive average distributed linear inverse solution was applied to periods of observed modulations. Just 70 ms after stimulus onset, a common network of brain regions within the auditory "what" processing stream responded more strongly to sounds of man-made versus living objects, with differential activity within the right temporal and left inferior frontal cortices. Over the 155-257 ms period, the duration of activity of a brain network, including bilateral temporal and premotor cortices, differed between categories of sounds. Responses to sounds of living objects peaked approximately 12 ms later and the activity of the brain network active over this period was prolonged relative to that in response to sounds of man-made objects. The earliest task-related effects were observed at approximately 100 ms poststimulus onset, placing an upper limit on the speed of cortical auditory object discrimination. These results provide critical temporal constraints on human auditory object recognition and semantic discrimination processes
Precise wide range heatmeters for 1.5 K up to 80 K
Two heatmeters were designed at CERN for applications below 20 K with the option to work also at temperatures up to 80 K. The new calibration principle and design permits the construction of wide rang e heatmeters with precision in the range of milliwatts. The calibration function takes into account the temperature dependence of the thermal conductivity of the heatmeter material. The heat flow meas urement is, therefore, independent of the base temperature, i.e. it is also independent on the temperature drop across thermal contact between heatmeter and the cold source. The simple calibration fun ction makes the heatmeter a user-friendly portable diagnostic device. It is possible to quantify parasitic heat flow without a previous calibration, or to calibrate the heatmeter during a measurement with a specimen
Swiss family physicians' perceptions and attitudes towards knowledge translation practices.
BACKGROUND: Several studies have been performed to understand the way family physicians apply knowledge from medical research in practice. However, very little is known concerning family physicians in Switzerland. In an environment in which information constantly accumulates, it is crucial to identify the major sources of scientific information that are used by family physicians to keep their medical knowledge up to date and barriers to use these sources. Our main objective was to examine medical knowledge translation (KT) practices of Swiss family physicians.
METHODS: The population consisted of French- and German-speaking private practice physicians specialised in family medicine. We conducted four interviews and three focus groups (n = 25). The interview guides of the semi-structured interviews and focus groups focused on (a) ways and means used by physicians to keep updated with information relevant to clinical practice; (b) how they consider their role in translating knowledge into practice; (c) potential barriers to KT; (d) solutions proposed by physicians for effective KT.
RESULTS: Family physicians find themselves rather ambivalent about the translation of knowledge based on scientific literature, but generally express much interest in KT. They often feel overwhelmed by "information floods" and perceive clinical practice guidelines and other supports to be of limited usefulness for their practice. They often combine various formal and informal information sources to keep their knowledge up to date. Swiss family physicians report considering themselves as artisans, caring for patients with complex needs.
CONCLUSION: Improved performance of KT initiatives in family medicine should be tailored to actual needs and based on high quality evidence-based sources
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