43 research outputs found

    The Dunkl–Williams constant, convexity, smoothness and normal structure

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    AbstractIn this paper we exhibit some connections between the Dunkl–Williams constant and some other well-known constants and notions. We establish bounds for the Dunkl–Williams constant that explain and quantify a characterization of uniformly nonsquare Banach spaces in terms of the Dunkl–Williams constant given by M. Baronti and P.L. Papini. We also study the relationship between Dunkl–Williams constant, the fixed point property for nonexpansive mappings and normal structure

    Low-cost irradiance sensors for irradiation assessments inside tree canopies.

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    The solar irradiation that a crop receives is directly related to the physical and biological processes that affect the crop. However, the assessment of solar irradiation poses certain problems when it must be measured through fruit inside the canopy of a tree. In such cases, it is necessary to check many test points, which usually requires an expensive data acquisition system. The use of conventional irradiance sensors increases the cost of the experiment, making them unsuitable. Nevertheless, it is still possible to perform a precise irradiance test with a reduced price by using low-cost sensors based on the photovoltaic effect. The aim of this work is to develop a low-cost sensor that permits the measurement of the irradiance inside the tree canopy. Two different technologies of solar cells were analyzed for their use in the measurement of solar irradiation levels inside tree canopies. Two data acquisition system setups were also tested and compared. Experiments were performed in Ademuz (Valencia, Spain) in September 2011 and September 2012 to check the validity of low-cost sensors based on solar cells and their associated data acquisition systems. The observed difference between solar irradiation at high and low positions was of 18.5% ± 2.58% at a 95% confidence interval. Large differences were observed between the operations of the two tested sensors. In the case of a-Si cells based mini-modules, an effect of partial shadowing was detected due to the larger size of the devices, the use of individual c-Si cells is recommended over a-Si cells based mini-modules

    Preventive Newborn Male Circumcision: What Is the Child's Best Interest?

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    Preventive newborn male circumcision has been at the center of scientific debate for many years. The reason for promoting preventive newborn male circumcision, is the reduction of the incidence of UTIs (in the first six months of life), penile cancer, transmission of STDs/HIV infection/AIDS. However preventive interventions in the newborn involving violations of bodily integrity elicit several ethical questions. In this article, we reviewed the literature regarding circumcision, the prevention of UTIs, penile cancer, transmission of STDs/HIV infection/AIDS and complications of this practice in the neonatal period. The very limited reduction of incidence of UTIs and the uncertain preventive role of newborn male circumcision towards penile cancer, STDs/HIV infection and AIDS, makes it difficult to justify male circumcision in newborns. Moreover, the challenge in obtaining a unanimous opinion on newborn male circumcision derives from the fact that, as a preventive intervention, it requires evaluation criteria that are not comparable to those of therapeutic treatments. Since preventive male circumcision determines permanent alteration of the body, some authors believe that it can be used only in subjects that are capable of giving their valid consent. In the case of a newborn, the ″child's best interest″ should be used as a standard, but preventive newborn male circumcision does not satisfy it

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    The fixed point property for some uniformly nonoctahedral Banach spaces

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    Measures of noncompactness and normal structure in Banach spaces

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    Sufficient conditions for normal structure of a Banach space are given. One of them implies reflexivity for Banach spaces with an unconditional basis, and also for Banach lattices
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