702 research outputs found

    Signal processing for a laser-Doppler blood perfusion meter

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    Two signal processing methods for laser-Dopper perfusion velocimetry are presented. The methods are based on the calculation of the moments of the frequency power spectrum. The first uses Vω-filtering (ω is the frequency) with analogous electronics, the second uses signal autocorrelation with digital electronics. Comparison is made with a third instrument: a spectrum analyzer coupled to a computer, using Fourier transform tecniques. The performance of these setups (sensitivity, limit sensitivity and accuracy) are investigated. We propose a calibration standard for signal processors to be used for blood perfusion measurements. The analogous instrument proved to be the cheapest but the digital instrument had the best performance

    Increasing altruistic and cooperative behaviour with simple moral nudges

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    The conflict between pro-self and pro-social behaviour is at the core of many key problems of our time, as, for example, the reduction of air pollution and the redistribution of scarce resources. For the well-being of our societies, it is thus crucial to find mechanisms to promote pro-social choices over egoistic ones. Particularly important, because cheap and easy to implement, are those mechanisms that can change people's behaviour without forbidding any options or significantly changing their economic incentives, the so-called "nudges". Previous research has found that moral nudges (e.g., making norms salient) can promote pro-social behaviour. However, little is known about whether their effect persists over time and spills across context. This question is key in light of research showing that pro-social actions are often followed by selfish actions, thus suggesting that some moral manipulations may backfire. Here we present a class of simple moral nudges that have a great positive impact on pro-sociality. In Studies 1-4 (total N = 1,400), we use economic games to demonstrate that asking subjects to self-report "what they think is the morally right thing to do" does not only increase pro-sociality in the choice immediately after, but also in subsequent choices, and even when the social context changes. In Study 5, we explore whether moral nudges promote charity donations to humanitarian organisations in a large (N = 1,800) crowdfunding campaign. We find that, in this context, moral nudges increase donations by about 44 percent

    Forehead Skin Blood Flow in Normal Neonates during Active and Quiet Sleep, Measured with a Diode Laser Doppler Instrument

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    Changes in forehead skin blood flow during active and quiet sleep were determined in 16 healthy neonates using a recently developed semi-conductor laser Doppler flow meter without light conducting fibres. Measurements were carried out at a postnatal age varying from 5 hours to 7 days. The two sleep states could be distinguished in 17 recordings. The mean skin blood flow values during active sleep were significantly higher (p<0.01) than those during quiet sleep, the mean increase being 28.1%. The variability of the flow signal, expressed as the coefficient of variation, changed significantly from 23.1% during active sleep to 18.2% during quiet sleep

    Controlled Doping Methods for Radial p/n Junctions in Silicon

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    P/n and n/p junctions with depths of 200 nm to several micrometers have been created in flat silicon substrates as well as on 3D microstructures by means of a variety of methods, including solid source dotation (SSD), low-pressure chemical vapor deposition (LPCVD), atmospheric pressure chemical vapor deposition, and plasma-enhanced chemical vapor deposition. Radial junctions in Si micropillars are inspected by optical and scanning electron micro­scopies, using a CrO3-based staining solution, which enables visualization of the junction depth. When applying identical-doping parameters to flat substrates, ball grooving, followed by staining and optical microscopy, yields similar junction depth values as high-resolution scanning electron microscopy imaging on stained cross-sections and secondary ion mass spectrometry depth profilometry. For the investigated 3D microstructures, doping based on SSD and LPCVD give uniform and conformal junctions. Junctions made with SSD-boron doping and CVD-phosphorus doping could be accurately predicted with a model based on Fick's diffusion law. 3D-microstructured silicon pillar arrays show an increased efficiency for sunlight capturing. The functionality of micropillar arrays with radial junctions is evidenced by improved short-circuit current densities and photovoltaic efficiencies compared with flat surfaces, for both n- and p-type wafers (average pillar arrays efficiencies of 9.4% and 11%, respectively, compared with 8.3% and 6.4% for the flat samples)

    Laser Doppler flowmeters prototypes: Monte Carlo simulations validation paired with measurements

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    Differences in lipid and blood pressure measurements between individuals with type 1 diabetes and the general population:a cross-sectional study

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    OBJECTIVES: Cardiovascular disease (CVD) is a precarious complication of type 1 diabetes (T1D). Alongside glycaemic control, lipid and blood pressure (BP) management are essential for the prevention of CVD. However, age-specific differences in lipid and BP between individuals with T1D and the general population are relatively unknown.DESIGN: Cross-sectional study.SETTING: Six diabetes outpatient clinics and individuals from the Lifelines cohort, a multigenerational cohort from the Northern Netherlands.PARTICIPANTS: 2178 adults with T1D and 146 22 individuals without diabetes from the general population.PRIMARY AND SECONDARY OUTCOME MEASURES: Total cholesterol, low-density lipoprotein cholesterol (LDL-cholesterol), systolic BP (SBP) and diastolic BP (DBP), stratified by age group, glycated haemoglobin category, medication use and sex.RESULTS: In total, 2178 individuals with T1D and 146 822 without diabetes were included in this study. Total cholesterol and LDL-cholesterol were lower and SBP and DBP were higher in individuals with T1D in comparison to the background population. When stratified by age and medication use, total cholesterol and LDL-cholesterol were lower and SBP and DBP were higher in the T1D population. Men with T1D achieved lower LDL-cholesterol levels both with and without medication in older age groups in comparison to women. Women with T1D had up to 8 mm Hg higher SBP compared with the background population, this difference was not present in men.CONCLUSIONS: Lipid and BP measurements are not comparable between individuals with T1D and the general population and are particularly unfavourable for BP in the T1D group. There are potential sex differences in the management of LDL-cholesterol and BP.</p

    Cardiovascular risk management in people with type 1 diabetes:performance using three guidelines

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    INTRODUCTION: Cardiovascular disease (CVD) is the leading cause of mortality in individuals with type 1 diabetes mellitus (T1DM). Cardiovascular risk management is therefore essential in the management of individuals with T1DM. This study describes the performance of lipid and blood pressure management in individuals with T1DM using three guidelines. RESEARCH DESIGN AND METHODS: Individuals ≥18 years with T1DM, treated with insulin for ≥1 year, visiting Diabeter or the University Medical Center Groningen between January 1, 2018 and December 31, 2018, were included. Lipid and blood pressure management were examined using the Dutch, American Diabetes Association (ADA) and National Institute for Health and Care Excellence (NICE) guidelines. Concordance of recommended and prescribed lipid-lowering (LLM) or antihypertensive medication (AHM) was assessed per guideline and 10-year age groups. Achievement of treatment targets was assessed for those prescribed medication. RESULTS: A total of 1855 individuals with T1DM were included. LLM and AHM was prescribed in 19% and 17%, respectively. In individuals recommended LLM, this was prescribed in 22%-46% according to Dutch, ADA or NICE guideline recommendations. For individuals recommended AHM, this was prescribed in 52%-75%. Recommended and actual prescription of LLM and AHM increased over age for all three guidelines. However, discordance between treatment recommendation and medication prescribed was higher in younger, compared with older, age groups. Low-density lipoprotein-cholesterol targets were achieved by 50% (without CVD) and 31% (with CVD) of those prescribed LLM. The blood pressure target was achieved by 46% of those prescribed AHM. CONCLUSION: This study suggests that there is undertreatment of lipid and blood pressure according to guideline recommendations, particularly in younger age groups. Treatment targets are not met by most individuals prescribed medication, while guidelines recommendations differ considerably. We recommend to investigate the factors influencing undertreatment of lipid and blood pressure management in individuals with T1DM

    Impact and sustainability of low-head drip irrigation kits, in the semi-arid Gwanda and Beitbridge Districts, Mzingwane Catchment, Limpopo Basin, Zimbabwe

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    Resource-poor smallholder farmers in the semi-arid Gwanda and Beitbridge districts face food insecurity on an annual basis due to a combination of poor and erratic rainfall (average 500 mm/a and 345 mm/a, respectively, for the period 1970–2003) and technologies inappropriate to their resource status. This impacts on both household livelihoods and food security. In an attempt to improve food security in the catchment a number of drip kit distribution programmes have been initiated since 2003 as part of an on-going global initiative aimed at 2 million poor households per year. A number of recent studies have assessed the technical performance of the drip kits in-lab and in-field. In early 2005 a study was undertaken to assess the impacts and sustainability of the drip kit programme. Representatives of the NGOs, local government, traditional leadership and agricultural extension officers were interviewed. Focus group discussions with beneficiaries and other villagers were held at village level. A survey of 114 households was then conducted in two districts, using a questionnaire developed from the output of the interviews and focus group discussions..

    Cannabis consumption and the risk of psychosis

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    Summary Objectives: Cannabis is the most widely used illicit drug globally and its use has been linked to an increased risk for psychotic disorders. An association between cannabis consumption and psychotic symptoms was consistently reported by several studies. This case-control study aimed to widen the current findings about the impact of cannabis exposure on the risk of psychosis, by investigating the pattern of cannabis consumption in a sample of first-episode of psychosis (FEP) patients compared to healthy controls. Material and methods: 68 individuals who presented for the first time to mental health services of Palermo (Italy) with an ICD-10 diagnosis of psychotic disorders and 74 healthy were enrolled as part of the Sicilian Genetics and Psychosis study. Psychopathological assessment and diagnosis were carried out by the Schedule for Clinical Assessment in Neuropsychiatry (SCAN). Socio-demographic data were collected by the modified version of the Medical Research Council (MRC) socio-demographic scale. All participants were interviewed using the Cannabis Experience Questionnaire \u2013 Modified Version to obtain a detailed assessment of lifetime patterns of cannabis and other illicit drug consumption. Logistic regression was applied to investigate the relationships between various aspects of cannabis use (lifetime use, age at first use, duration, and frequency of use) and case-control status while controlling for potential confounders. Results: Patients started cannabis consumption about 3 years earlier than the control group (t = 3.1, p = 0.002) and were 8 times more likely to having started using cannabis before 15 years (adjusted OR = 8.0, 95% CI 2.4-27) than controls. Furthermore cases were more likely to smoke more frequently than controls (adjusted OR = 4.4, 95% CI 1.08-18). We did not find a difference in duration of cannabis use between cases and controls. Conclusions: The findings suggest that cannabis exposure, and especially daily cannabis consumption, is associated with the risk for psychosis; however, the retrospective study design does not allow drawing firm conclusions about causality

    Early onset as a marker for disease severity in facioscapulohumeral muscular dystrophy

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    Contains fulltext : 202651.pdf (publisher's version ) (Open Access)OBJECTIVE: To assess the relation between age at onset and disease severity in facioscapulohumeral muscular dystrophy (FSHD). METHODS: In this prospective cross-sectional study, we matched adult patients with FSHD with an early disease onset with 2 sex-matched FSHD control groups with a classic onset; the first group was age matched, and the second group was disease duration matched. Genetic characteristics, muscle performance, respiratory functioning, hearing loss, vision loss, epilepsy, educational level, and work status were compared with the 2 control groups. RESULTS: Twenty-eight patients with early-onset FSHD were age (n = 28) or duration (n = 27) matched with classic-onset patients. Patients with early-onset FSHD had more severe muscle weakness (mean FSHD clinical score 11 vs 5 in the age-matched and 9 in the duration-matched group, p < 0.05) and a higher frequency of wheelchair dependency (57%, 0%, and 30%, respectively, p < 0.05). In addition, systemic features were more frequent in early-onset FSHD, most important, hearing loss, decreased respiratory function and spinal deformities. There was no difference in work status. Genetically, the shortest D4Z4 repeat arrays (2-3 units) were found exclusively in the early-onset group, and the largest repeat arrays (8-9 units) were found only in the classic-onset groups. De novo mutations were more frequent in early-onset patients (46% vs 4%). CONCLUSIONS: Patients with early-onset FSHD more often have severe muscle weakness and systemic features. The disease severity is greater than in patients with classic-onset FSHD who are matched for disease duration, suggesting that the progression is faster in early-onset patients
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