3,148 research outputs found

    Common fixed points for self-mappings on partial metric spaces

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    In this paper, we prove some results of a common fixed point for two self-mappings on partial metric spaces. Our results generalize some interesting results of Ilic et al. (Appl. Math. Lett. 24:1326-1330, 2011). We conclude with a result of the existence of a fixed point for set-valued mappings in the context of 0-complete partial metric spaces

    A rapid aerodynamic prediction method for unconventional transonic aircraft configurations

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    This paper presents some results comparing the use of the Full Potential equations, coupled with the turbulent integral boundary layer equations for aircraft transonic cruise analysis. Use of such a method in the conceptual design stage is shown to be capable of yielding accurate enough data in a few minutes on a single processor, where Navier - Stokes simulations on 100+ processors take several days

    Ill-lighting syndrome: prevalence in shift-work personnel in the anaesthesiology and intensive care department of three Italian hospitals

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    <p>Abstract</p> <p>Background</p> <p>Light is one of the most important factors in our interaction with the environment; it is indispensable to visual function and neuroendocrine regulation, and is essential to our emotional perception and evaluation of the environment. Previous studies have focussed on the effects of prolonged anomalous exposure to artificial light and, in the field of work-related illness. Studies have been carried out on shift-work personnel, who are obliged to experience alterations in the physiological alternation of day and night, with anomalous exposure to light stimuli in hours normally reserved for sleep. In order to identify any signs and symptoms of the so-called ill-lighting syndrome, we carried out a study on a sample of anaesthesiologists and nurses employed in the operating theatres and Intensive Care Departments of three Italian hospitals. We measured the subjective emotional discomfort (stress) experienced by these subjects, and its correlation with environmental discomfort factors, in particular the level of lighting, in their workplace.</p> <p>Methods</p> <p>We used a questionnaire developed by the Scandinavian teams who investigated Sick-Building Syndrome, that was self-administered on one day in the environments where the degree of illumination was measured according to UNIEN12464-1 regulations.</p> <p>Results</p> <p>Upon comparison of the types of exposure with the horizontal luminance values (lux) measured (< 700 lux, between 1000–1500 lux, > 1500 lux) and the degree of stress reported, (Intensive Care: mean stress = 55.8%, high stress = 34.6%; Operating Theatres: mean stress = 51.5%, high stress = 33.8%), it can be observed that the percentage of high stress was reduced as the exposure to luminance was increased, although this finding was not statistically significant.</p> <p>Conclusion</p> <p>We cannot share other authors' enthusiasm regarding the effects on workers well-being correlated to the use of fluorescent lighting. The stress level of our workers was found to be more heavily influenced by their familial and working conditions, irrespective of the ambient light stimulus.</p

    Effects of ewes grazing sulla or ryegrass pasture for different daily durations on forage intake, milk production and fatty acid composition of cheese

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    Sulla (Sulla coronarium L.) forage is valued for its positive impact on ruminant production, in part due to its moderate content of condensed tannin (CT). The duration of daily grazing is a factor affecting the feed intake and milk production of ewes. In this study, the effects of grazing sulla pasture compared with annual ryegrass, and the extension of grazing from 8 to 22 h/day, were evaluated with regard to ewe forage intake and milk production, as well as the physicochemical properties and fatty acid (FA) composition of cheese. During 42 days in the spring, 28 ewes of the Comisana breed were divided into four groups (S8, S22, R8 and R22) that grazed sulla (S) or ryegrass (R) for 8 (0800 to 1600 h) or 22 h/day, and received no feeding supplement. In six cheese-making sessions, cheeses were manufactured from the 48 h bulk milk of each group. Compared with ewes grazing ryegrass, those grazing sulla had higher dry matter (DM) intake, intake rate and milk yield, and produced milk that was lower in fat and higher in casein. Ewes grazing for 22 h spent more time eating, which reduced the intake rate, increased DM and nutrient intake and milk yield, and reduced milk fat. Due to the ability of CT to inhibit the complete ruminal biohydrogenation of polyunsaturated fatty acids (PUFA), the FA composition of sulla cheese was more beneficial for consumer health compared with ryegrass cheese, having lower levels of saturated fatty acids and higher levels of PUFA and n-3 FA. The FA profile of S8 cheese was better than that of S22 cheese, as it was higher in branched-chain FA, monounsaturated FA, PUFA, rumenic acid (c9,t11-C18:2), and had a greater health-promoting index. The effect of short grazing time on sulla was attributed to major inhibition of PUFA biohydrogenating ruminal bacteria, presumably stimulated by the higher accumulation of sulla CT in the rumen, which is related to a higher intake rate over a shorter eating time. Thus, grazing sulla improved the performance of ewes, thereby increasing, especially with short grazing time, the nutritional properties of cheese fat

    Changes in airway hyperresponsiveness following smoking cessation: Comparisons between Mch and AMP

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    SummaryBackgroundGiven the observed association between smoking, inflammation and airway hyperresponsiveness (AHR) one may predict that smoking cessation may improve AHR. However, only a few studies have investigated the effect of smoking on AHR and their results appear to be conflicting depending on the stimulus used in their bronchoprovocation protocol. The aim of the current study was to compare changes in AHR between direct (methacholine (Mch)) and indirect (adenosine 5′monophosphate (AMP)) stimuli before and at different time points after smoking cessation in smokers with allergic rhinitis (±asthma).MethodsWe have prospectively studied changes in AHR to inhaled Mch and AMP in smokers with allergic rhinitis (±asthma), before and at 6 and 12 months after smoking cessation.ResultsIt was found that 28% (16/57) of the participants had quit smoking by the end of the study. No significant change in AHR was observed in smoking cessation failures. A significant improvement in AHR to AMP but not Mch was observed 6 months after smoking cessation in quitters; a 1.2 doubling concentrations change in PC20 AMP was measured whereas only a 0.4 doubling concentrations change was observed for PC20 Mch. However, after 12 months smoking cessation the improvement in AHR became significant for both AMP and Mch, their dose–response curves being displaced to the right to a similar extent (1.4 and 1.1 doubling concentrations for AMP and Mch, respectively).ConclusionSmoking cessation can improve AHR in smokers who quit with a 6 months improvement being reported for the airways response to AMP but not Mch. AMP challenge may detect earlier changes in AHR in smokers during smoking cessation

    Individual Differences, Economic Stability, and Fear of Contagion as Risk Factors for PTSD Symptoms in the COVID-19 Emergency

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    On January 30th 2020, the World Health Organization (WHO) declared the COVID-19 pandemic a Public Health Emergency of International Concern (PHEIC). Italy has been one of the most affected countries in the world. To contain further spread of the virus, the Italian government has imposed an unprecedented long-period lockdown for the entire country. This dramatic scenario may have caused a strong psychological distress, with potential negative long-term mental health consequences. The aim of the present study is to report the prevalence of high psychological distress due to the COVID-19 pandemic on the general population, especially considering that this aspect is consistently associated with PTSD symptoms. Furthermore, the present study aims to identify the risk factors for high PTSD symptoms, including individual differences and subjective perception of both economic and psychological aspects. We administered an online survey to 1253 participants during the peak period of the contagion in Italy. A logistic regression on the Impact of Event Scale – Revised (IES-R) scores was used to test the risk factors that predict the possibility to develop PTSD symptoms due to the COVID-19 pandemic. Gender (female), lower perceived economic stability, higher neuroticism, and fear and consequences of contagion were predictors of high PTSD symptomatology. The results, highlighted in the present study, extend our understanding of the COVID-19 pandemic’s impact on the population’s mental health, by identifying individuals at high-risk of developing PTSD. This may help with the implementation of specific protocols to prevent the possibility of developing symptoms of PTSD in target populations

    Psychological Factors and Consumer Behavior During the COVID-19 Pandemic

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    The COVID-19 pandemic is far more than a health crisis: it has unpredictably changed our whole way of life. As suggested by the analysis of economic data on sales, this dramatic scenario has also heavily impacted individuals’ spending levels. To better understand these changes, the present study focused on consumer behavior and its psychological antecedents. Previous studies found that crises differently affect people’s willingness to buy necessities products (i.e., utilitarian shopping) and non-necessities products (i.e., hedonic shopping). Therefore, in examining whether changes in spending levels were associated with changes in consumer behavior, we adopted a fine-grained approach disentangling between necessities and non-necessities. We administered an online survey to 3833 participants (age range 18–64) during the first peak period of the contagion in Italy. Consumer behavior toward necessities was predicted by anxiety and COVID-related fear, whereas consumer behavior toward non-necessities was predicted by depression. Furthermore, consumer behavior toward necessities and non-necessities was predicted by personality traits, perceived economic stability, and self-justifications for purchasing. The present study extended our understanding of consumer behavior changes during the COVID-19 pandemic. Results could be helpful to develop marketing strategies that consider psychological factors to meet actual consumers’ needs and feelings

    Multidisciplinary studies on a sick-leader syndrome-associated mass stranding of sperm whales (Physeter macrocephalus) along the Adriatic coast of Italy

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    Mass strandings of sperm whales (Physeter macrocephalus) are rare in the Mediterranean Sea. Nevertheless, in 2014 a pod of 7 specimens stranded alive along the Italian coast of the Central Adriatic Sea: 3 individuals died on the beach after a few hours due to internal damages induced by prolonged recumbency; the remaining 4 whales were refloated after great efforts. All the dead animals were genetically related females; one was pregnant. All the animals were infected by dolphin morbillivirus (DMV) and the pregnant whale was also affected by a severe nephropathy due to a large kidney stone. Other analyses ruled out other possible relevant factors related to weather conditions or human activities. The results of multidisciplinary post-mortem analyses revealed that the 7 sperm whales entered the Adriatic Sea encountering adverse weather conditions and then kept heading northward following the pregnant but sick leader of the pod, thereby reaching the stranding site. DMV infection most likely played a crucial role in impairing the health condition and orientation abilities of the whales. They did not steer back towards deeper waters, but eventually stranded along the Central Adriatic Sea coastline, a real trap for sperm whales
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