807 research outputs found

    Correlative analyses for Homestake neutrino data

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    We present results from linear correlative analyses between Homestake data and several solar-activity parameters in the period 1970-1992. Our findings support the hypothesis that the observed neutrino flux exhibits a significative correlation with some solar-activity parameters, particularly with those related with the heliomagnetic field

    Effect of the Pin Geometry on the Wear Behavior of Weld-Deposited Hardfacing

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    AbstractHarfacing welding is a widely used method on severe worn, corroded or oxidized surfaces to regain its functionality. For metal-to-metal sliding or rolling contact applications, in which oxidative wear, subsurface fatigue and adhesive wear are the main wear mechanisms, the materials usually selected are steels with a carbon contents between 0,1 and 0,7% and up to 20% of alloy content, such as martensitic tool steels. Among them, H13 tool steel has a great number of applications. Variables such as sliding speed, load, or contact stress may have decisive influence on wear rates. Laboratory tests like Pin-On-Disk (POD) are frequently used to evaluate the tribologic behaviour of different pairs of material. The objective of this work was to study the influence of the pin geometry (flat and spherical) in a POD test on the wear resistance of a weld-deposited hardfacing of H13 modified steel against low carbon steel AISI 1020 under different load and sliding speed conditions. It was observed an influence of the pin geometry on the wear rates, especially at high sliding speeds. Under light loads, the worn volume of the flat pin was greater, while under heavier loads it is the spherical pin the one with greater worn amount

    An Abstract Birkhoff Normal Form Theorem and Exponential Type Stability of the 1d NLS

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    We study stability times for a family of parameter dependent nonlinear Schrodinger equations on the circle, close to the origin. Imposing a suitable Diophantine condition (first introduced by Bourgain), we prove a rather flexible Birkhoff Normal Form theorem, which implies, e.g., exponential and sub-exponential time estimates in the Sobolev and Gevrey class respectively

    Functional Tricuspid Regurgitation Repair at the time of Left-Sided Valve Surgery. the Impact on the Cardiac Rehabilitation Program

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    Objective: to compare the early post-operative functional status and the efficacy of the cardiac rehabilitation program (CRP) after isolated left-sided valvular surgery or with concomitant tricuspid valve repair (TVR). Methods: we retrospectively enrolled patients admitted to the Cardiac Rehabilitation Unit of our institution from January 2014 to January 2019, following mitral or aortic valve surgery. In agreement with current guidelines, concomitant tricuspid annuloplasty was added to patients with severe functional tricuspid regurgitation (TR) and in those with mild to moderate TR when annulus dilatation was present. A 6-minute walk test (6mWT) was performed within the second day of admission and repeated predischarge. The distances walked on the 6mWT were reported as absolute value and as a percentage of the predicted value, taking into account anthropometric variables. Changes in the 6mWT performance and Barthel index (BI) were assessed to evaluate the impact of CRP on exercise tolerance and functional independence, respectively. Results: of 117 patients, 62 (53%) had isolated left-sided valvular surgery and 55 (47%) had concomitant TVR. There were no significant differences between the two groups in the baseline 6mWT performance and its improvement at the end of CRP. TVR was associated with a worse BI on admission, but with a greater improvement after the CRP and a pre-discharge BI comparable to isolated left-sided surgery. Upon linear regression analysis, diabetes and chronic renal disease were predictors of the baseline 6mWT performance. Conclusion: TVR does not affect the early post-operative functional status and the efficacy of the CRP after valvular surgery

    UTCI field measurements in an urban park in Florence (Italy)

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    The aim of this study is to evaluate human thermal comfort in different green area settings in the city of Florence by using the Universal Thermal Climate Index (UTCI). Field measurements of air temperature, solar radiation, relative humidity, wind speed and black globe thermometer were collected during hot summer days in various parts of Cascine Park, the biggest urban park in Florence (Italy). UTCI was evaluated over different surfaces (asphalt, gravel and grass) completely exposed to the sun or shaded by a large lime tree (Tilia × europaea). The results showed strong differences in UTCI values depending on the exposure to tree shade, while no significant difference was found among ground-cover materials when all surfaces were equally exposed to solar radiation. Future studies are needed to investigate the microclimatic effects of different tree species on UTCI

    Prescribing pattern insights from a longitudinal study of older adult inpatients with polypharmacy and chronic non-cancer pain.

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    BACKGROUND The present study sought to determine the prevalence of chronic non-cancer pain (CNCP) among older adult inpatients with polypharmacy. It also aimed to analyse prescription patterns and assess the therapy adequacy and patient complexity for those with and without CNCP. METHODS This 4-year longitudinal study examined data from an exhaustive acute care hospital register on home-dwelling older adult patients (≥65) with polypharmacy. Commonly known combinations of potentially inappropriate medications were used to estimate therapy adequacy. Patient complexity was evaluated by comparing number of comorbidities and investigating physical and cognitive deficits. RESULTS We determined a prevalence of CNCP of 9.7% among all older adult inpatients with polypharmacy, rising to 11.3% for those aged ≥85. Overall, CNCP patients were prescribed more drugs and had more comorbidities and physical and cognitive deficits than patients without CNCP. Older adult patients with CNCP received more analgesics, greater quantities of opioids, paracetamol and co-analgesics and elevated opioid dosages. Older adult patients with CNCP aged ≥85 received fewer analgesics, opioids, non-steroidal anti-inflammatory drugs and co-analgesics but more paracetamol. Older adult patients with CNCP were prescribed more potentially inappropriate medications involving opioids. In particular, 24.5% received an opioid and a hypnotic (benzodiazepine or Z-drug), and 8.6% received an opioid and a gabapentinoid. CONCLUSION Observed differences in medication use between older adult inpatients with or without CNCP may be relevant for clinical practice. Potentially inadequate co-prescribing (such as hypnotics and opioids) affects a higher proportion of patients with CNCP and may have serious unintended consequences. SIGNIFICANCE STATEMENT This study describes differences in prescription patterns between people with and without chronic non-cancer pain in a large dataset of 20,422 discharges. The differences found may be relevant to clinical practice. In particular, high co-prescribing of opioids and hypnotics may have serious unintended consequences. Greater physical and cognitive deficits may indicate greater patient complexity, and appropriate interventions need to be developed to improve the management of this vulnerable patient group

    Central obesity in Yemeni children: A population based cross-sectional study

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    AIM: To establish percentile curves and to explore prevalence and correlates of central obesity among Yemeni children in a population based cross-sectional study. METHODS: A representative sample of 3114 Yemeni children (1564 boys, 1550 girls) aged 6-19 years participating in the HYpertension and Diabetes in Yemen study was studied. Data collection was conducted at home by survey teams composed of two investigators of both genders. Study questionnaire included questions about demographics, lifestyle, and medical history. Anthropometric measurements included body weight, height, waist circumference (WC) and hip circumferences. Waist to hip ratio (WHR) and waist-to-height ratio (WHtR) were then calculated. Age and gender specific smoothed percentiles of WC, WHR, and WHtR were obtained using lambda-mu-sigma parameters (LMS method). The independent predictors of central obesity defined as (1) WC percentile ≥ 90(th); (2) WHtR ≥ 0.5; or (3) WC percentile ≥ 90(th) and WHtR ≥ 0.5, were identified at multivariate logistic regression analysis adjusted for age, gender, urban/rural location, years of school education, sedentary/active life-style. RESULTS: Percentile curves for WC, WHR and WHtR are presented. Average WC increased with age for both genders. Boys had a higher WC than girls until early adolescence and thereafter girls had higher values than boys. WHR decreased both in boys and girls until early adolescence. Thereafter while in boys it plateaued in girls it continued to decrease. Mean WHtR decreased until early adolescence with no gender related differences and thereafter increased more in girls than in boys towards adult age. Prevalence of central obesity largely varied according to the definition used which was 10.9% for WC ≥ 90(th) percentile, 18.3% for WHtR ≥ 0.5, and 8.6% when fulfilling both criteria. At adjusted logistic regression WC ≥ 90(th) percentiles and WHtR ≥ 0.5 were less prevalent in rural than in urban areas (OR = 0.52, 95%CI: 0.41-0.67 and 0.66, 0.54-0.79 respectively), being more prevalent in children with sedentary lifestyle rather than an active one (1.52, 95%CI: 1.17-1.98 and 1.42, 95%CI: 1.14-1.75, respectively). CONCLUSION: Yemeni children central obesity indices percentile curves are presented. Central obesity prevalence varied according to the definition used and was more prevalent in urban sedentary subjects

    Relationship Characteristics Associated with Teen Dating Violence Perpetration

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    Teen dating violence (TDV) is unstable across dating relationships, suggesting that characteristics of the relationship could be related to TDV. Few empirical studies have examined these links. This study examined associations between relationship characteristics and TDV perpetration among teens and sex differences in those associations. Relationship characteristics examined include tactics used to manipulate partners; ways of responding to relationship problems; relationship duration; exclusivity of the relationship; age difference between partners; and history of sexual intercourse with partner. Data were drawn from 667 teens in a current relationship (62.5% female and 81.4% white) enrolled in the 11th or 12th grade in 14 public schools in a rural US state. Bivariate and multivariable regression analyses examined proposed associations. 30.1% and 8.2% of teens reported controlling and physical TDV perpetration, respectively. In multivariable models, frequent use manipulation tactics increased risk for controlling or physical TDV perpetration. Teens dating a partner two or more years younger were at significantly increased risk for both controlling and physical perpetration. A significant interaction emerged between sex and exit/neglect accommodation for physical TDV. Characteristics of a current dating relationship play an important role in determining risk for controlling and physical TDV perpetration
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