583 research outputs found

    Fertimetro, a Principle and Device to Measure Soil Nutrient Availability for Plants by Microbial Degradation Rates on Differently-Spiked Buried Threads

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    A novel patented method (PCT/IB2012/001157: Squartini, Concheri, Tiozzo, University of Padova) and the corresponding application devices, suitable to measure soil fertility, are presented. The availability or deficiency of specific nutrients for crops is assessed by monitoring the kinetics of progressive weakening of cotton or silk threads due to in situ microbial activity. The method is based on a nutrient-primed incremented substrate degradation principle. Threads are buried as is or pre-impregnated with N or P solutions, and the acceleration of the degradation rate for the N-supplemented or P-supplemented thread, in comparison to the untreated thread, is proportional to the lack of the corresponding nutrient in that soil. Tests were validated on corn crops in plots receiving increasing fertilizer rates in a historical rotation that has been established since 1962. The measurement carried out in May significantly correlated with the subsequent crop yields recorded in October. The analysis allows an early, inexpensive, fast, and reproducible self-assessment at field level to improve fertilization rates. The device is envisaged as a user-friendly tool for agronomy, horticulture, and any environmental applications where organic matter cycling, soil quality, and specific nutrients excess or deficiency are critical considerations

    The entropy of alpha-continued fractions: numerical results

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    We consider the one-parameter family of interval maps arising from generalized continued fraction expansions known as alpha-continued fractions. For such maps, we perform a numerical study of the behaviour of metric entropy as a function of the parameter. The behaviour of entropy is known to be quite regular for parameters for which a matching condition on the orbits of the endpoints holds. We give a detailed description of the set M where this condition is met: it consists of a countable union of open intervals, corresponding to different combinatorial data, which appear to be arranged in a hierarchical structure. Our experimental data suggest that the complement of M is a proper subset of the set of bounded-type numbers, hence it has measure zero. Furthermore, we give evidence that the entropy on matching intervals is smooth; on the other hand, we can construct points outside of M on which it is not even locally monotone.Comment: 33 pages, 14 figure

    Cross sections for geodesic flows and \alpha-continued fractions

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    We adjust Arnoux's coding, in terms of regular continued fractions, of the geodesic flow on the modular surface to give a cross section on which the return map is a double cover of the natural extension for the \alpha-continued fractions, for each α\alpha in (0,1]. The argument is sufficiently robust to apply to the Rosen continued fractions and their recently introduced \alpha-variants.Comment: 20 pages, 2 figure

    OC47 – NICUs and family-centred care, from the leadership to the design, the results of a survey in Italy (by FCC Italian NICU study group)

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    Introduction: Family-centered care (FCC) in NICUs is related to staff culture and the organization of the unit. Aim: To describe the organizational characteristics and services for families in Italian NICUs. Methods: This survey involved 105 NICUs in Italy. The Italian version of the ‘FCC in the NICUs: A Self-Assessment Inventory’ developed by the Institute for FCC was sent to the nurse managers in January 2015. Results: Forty-seven NICUs answered (49%). The means of the NICU characteristics are number of beds: 20; newborns discharged/year: 331, of which very low birth weight infant: 68; unit’s rooms: 3.7). The total mean score of the 10 areas explored by questionnaire was 2.6 (on 5 points Likert scale) for the ‘status’ and of 2.3 (on 3 points scale) for priority for change. Conclusion: The results show an organizational lack, but also the consciousness of the need of change. Sharing new organizational strategies could be an important issue for the future

    Natural extensions and entropy of α\alpha-continued fractions

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    We construct a natural extension for each of Nakada's α\alpha-continued fractions and show the continuity as a function of α\alpha of both the entropy and the measure of the natural extension domain with respect to the density function (1+xy)−2(1+xy)^{-2}. In particular, we show that, for all 0<α≤10 < \alpha \le 1, the product of the entropy with the measure of the domain equals π2/6\pi^2/6. As a key step, we give the explicit relationship between the α\alpha-expansion of α−1\alpha-1 and of α\alpha

    Instruments Measuring Self-Care in Children and Young Adults With Chronic Conditions: A Systematic Review

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    : Children and young adults (CYAs) with chronic conditions need to engage in self-care to improve their quality of life. This study aimed to retrieve the literature on instruments to assess self-care in CYAs living with chronic conditions and evaluate the psychometric proprieties of the instruments retrieved. A systematic literature review was conducted on six databases to identify peer-reviewed papers that described or used an evaluation instrument of self-care in CYAs with chronic conditions. Twenty-three articles describing 11 instruments of self-care were identified. Five instruments (45.45%) were developed for specific diseases, while six (54.54%) for various chronic illnesses. Most of the instruments were focused on treatment adherence within self-care maintenance (i.e., behaviors to maintain illness stability), excluding the monitoring of clinical parameters or the management of exacerbations. This review provides an overview of available instruments that measure self-care in CYAs with chronic conditions, which health professionals could use for patient education

    A cross-sectional assessment of metabolic syndrome in HIV-infected people of low socioeconomic status receiving antiretroviral therapy

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    BACKGROUND: Metabolic syndrome (MetS) is a constellation of symptoms used as a measure to identify patients at increased risk for cardiovascular disease, type 2 diabetes, and all-cause mortality. The results of prolonged life expectancy and cumulative toxic effects of antiretroviral therapy increase the chance that HIV can cause clinical abnormalities, including MetS. METHODS: We evaluated 89 people living with HIV (PLWH; mean age 48 ± 7 years; mean duration of HIV infection 17 ± 12 years; 47% men; 66% African-American, 22% Hispanic, and 10% non-Hispanic white; and 84% unemployed) enrolled in a community-based exercise training and nutrition education program targeting individuals of low socio-economic status (SES). The prevalence of MetS characteristics and the factors associated with the presence of MetS were analyzed. RESULTS: One in three (33%; 12 men and 17 women) PLWH met ATPIII criteria for MetS. In our cohort, MetS was driven by high waist circumference and elevated blood pressure. In addition, higher use of protease inhibitors, elevated hemoglobin A1c (HbA1c), greater self-reported daily caloric intake and consumption of carbohydrates, sugar, added sugar, and higher glycemic load were found among the individuals with MetS, compared to those without it. Elevated HbA1c and high total sugar consumption were the strongest predictors and accounted for 30% of the occurrence of MetS. CONCLUSIONS: The overall prevalence of MetS in our PLWH cohort receiving antiretroviral therapy is higher than previously reported in the general population and in other PLWH cohorts. Additional work is needed to determine whether MetS is a more disease dependent or lifestyle dependent condition in PLWH

    Hyaluronan uptake by adult human skin fibroblasts in vitro

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    Low and high molecular weight hyaluronan (HA) was added to adult human fibroblasts grown in monolayer to assess its influence on CD44 expression, its internalisation and effect on cell growth. CD44 expression on the surface of in vitro fibroblasts was not modified by different concentrations of FCS, whereas it was sensitive to cell cycle, being higher in the growing than in the resting phase. Independently from molecular weight, upon addition of exogenous HA (from 0.1 up to 1 mg/mL) to fibroblasts in the growing phase, a slight but constant decrease of the expression of CD44 on the surface of fibroblasts was observed; moreover, HA induced a rearrangement of CD44 into patches in close relationship with the terminal regions of stress fibers, which became thicker and more rigid after a few hours from the addition of HA to the medium. Fluorescent HA, added to the culture medium, rapidly attached to the plasma membrane and in less than two minutes was observed within cells, partly in association with its receptor CD44. By the contemporary use of neutral red, which accumulates into functional lysosomes, the great majority of internalised HA was found within lysosomes. HA receptor RHAMM-IHABP was rather homogeneously localised within the cytoplasm of normal growing fibroblasts. Upon addition of HA, the RHAMM-IHABP distribution became discontinuous around the nucleus. Addition of HA to fibroblasts induced a significant inhibition of cell growth, which was dependent on HA concentration and irrespective of HA molecular weight, at least in the ranges tested. Results show that extra-cellular HA is rapidly taken up by human dermal fibroblasts together with its CD44 receptor, and transported mostly to the lysosomes. Both low and high molecular weight HA induced down-regulation of cell proliferation, which would seem to be mediated by HA catabolism
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