681 research outputs found
The Stochastic Container Relocation Problem
The Container Relocation Problem (CRP) is concerned with finding a sequence of moves of containers that minimizes the number of relocations needed to retrieve all containers, while respecting a given order of retrieval. However, the assumption of knowing the full retrieval order of containers
is particularly unrealistic in real operations. This paper studies the stochastic CRP (SCRP), which relaxes this assumption. A new multi-stage stochastic model, called the batch model, is introduced, motivated, and compared with an existing model (the online model). The two main contributions are an
optimal algorithm called Pruning-Best-First-Search (PBFS) and a randomized approximate algorithm called PBFS-Approximate with a bounded average error. Both algorithms, applicable in the batch and online models, are based on a new family of lower bounds for which we show some theoretical properties. Moreover, we introduce two new heuristics outperforming the best existing heuristics. Algorithms, bounds and heuristics are tested in an extensive computational section. Finally, based on strong computational evidence, we conjecture the optimality of the âLevelingâ heuristic in a special âno informationâ case, where at any retrieval stage, any of the remaining containers is equally likely to be retrieved next
Effects of Probiotics Supplementation on Risk and Severity of Infections in Athletes: A Systematic Review
The aim of this review was to appraise the literature on the effects of probiotics supplementation on gastrointestinal (GI) and upper respiratory tract infection (URTI) risk and prognosis in athletes. The search was conducted using the following electronic databases: MEDLINE (PubMed); Web of Science; Scopus; and SPORTDiscus (EBSCO). According to the PRISMA guidelines, randomized controlled studies performed on healthy athletes with a note dose of probiotics supplementation were considered. From the 2304 articles found, after eliminating reviews and studies on animals and unhealthy subjects and after screening of titles and abstracts, 403 studies were considered eligible. From these, in accordance with the inclusion and exclusion criteria, 16 studies were selected, ten of which concerned endurance athletes. The majority of the studies reported beneficial effects of probiotics in reducing the risk of developing the examined infections or the severity of related symptoms. However, due to the differences in formulations used and populations analyzed in the available studies, further research is needed in this field to achieve stronger and more specific evidence
Are health literacy and lifestyle of undergraduates related to the educational field? An italian survey
Background: Health literacy (HL) is a fundamental ability to successfully deal with health and illness issues. This study aimed to assess HL among undergraduates from healthcare and non-healthcare degree courses of two Italian universities and the association between their HL, lifestyles, and BMI assumed as health outcome. Methods: The Health Literacy Assessment Tool (HLAT-8) and the Newest Vital Sign (NVS) were used to assess health literacy dimensions. Demographic and anthropometric data, adherence to Mediterranean diet (MD), physical activity levels, and smoking habits were assessed in the enrolled sample to highlight possible associations. Results: A total sample of 806 undergraduates (46% males, mean age 21.01 ± 1.78 years) was recruited. Higher HL scores were found among healthcare rather than non-healthcare students (28.7 ± 4.5 vs. 26.7 ± 4.2 for HLAT-8 and 4.9 ± 1.5 vs. 3.9 ± 1.8 for NVS, p < 0.01). However, healthcare undergraduates were more likely to report unhealthy behaviors. Body Mass Index (BMI) was associated with literacy and numeracy skills only in non-healthcare undergraduates. Significant associations were found between HL scores and adherence to MD in both groups. In the regression analysis, educational field and MD were shown to be predictors of HL scores. Conclusions: Attending a healthcare related degree course was associated with higher HL scores but not with healthy behaviors. This issue should be addressed considering the role that healthcare professionals may have in educating patients towards a healthy lifestyle. Adherence to MD seems to be related to higher HL scores
Classroom active breaks to increase childrenâs physical activity: A cross-sectional study in the province of Naples, Italy
Background: Classroom Active Breaks (CABs), short active sessions integrated in the school time, have been recognized as a promising tool to reduce sedentary behavior and increase Physical Activity (PA) levels in children. âAulAttivaâ is a six-month CABs-based program implemented in primary schools of the province of Naples. The aim of this study was to evaluate its effectiveness by comparing PA and sedentary time of participating pupils respect to a control group, considering also their weight status. Methods: Four third-grade classes, each from 4 schools out of 32 participating in AulAttiva, and 4 third-grade classes, each from 4 schools out of 74 that did not take part, were randomly selected. Finally, 58 children composed the intervention group and 57 the control group. Age, gender, weight and height were registered for each participant. Weight status was classified as non-overweight and overweight/obesity. Sedentary time and PA were assessed through accelerometers along a school day. Results: Light PA was 4 min higher in the AulAttiva group with respect to controls (p = 0.046). Within the non-overweight children, the AulAttiva group spent less time in sedentary behavior and more time in light and total PA than controls. No significant differences were found between the overweight/obese subgroups. Conclusions: The results support the effectiveness of CABs in increasing PA during the school day. Greater effects were registered among normal weight pupils, suggesting the possible influence of weight status on childrenâs participation to the intervention. Further studies are needed to improve the compliance of overweight/obese children to this intervention
Early in-flight detection of SO<sub>2</sub> via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes
Volcanic ash constitutes a risk to aviation, mainly due to its ability to cause jet engines to fail. Other risks include the possibility of abrasion of windshields and potentially serious damage to avionic systems. These hazards have been widely recognized since the early 1980s, when volcanic ash provoked several incidents of engine failure in commercial aircraft. In addition to volcanic ash, volcanic gases also pose a threat. Prolonged and/or cumulative exposure to sulphur dioxide (SO<sub>2</sub>) or sulphuric acid (H<sub>2</sub>SO<sub>4</sub>) aerosols potentially affects e.g. windows, air frame and may cause permanent damage to engines. SO<sub>2</sub> receives most attention among the gas species commonly found in volcanic plumes because its presence above the lower troposphere is a clear proxy for a volcanic cloud and indicates that fine ash could also be present. <br><br> Up to now, remote sensing of SO<sub>2</sub> via Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet spectral region has been used to measure volcanic clouds from ground based, airborne and satellite platforms. Attention has been given to volcanic emission strength, chemistry inside volcanic clouds and measurement procedures were adapted accordingly. Here we present a set of experimental and model results, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO<sub>2</sub> in two spatial dimensions. In order to prove our new concept, simultaneous airborne and ground-based measurements of the plume of PopocatĂ©petl volcano, Mexico, were conducted in April 2010. The plume extended at an altitude around 5250 m above sea level and was approached and traversed at the same altitude with several forward looking DOAS systems aboard an airplane. These DOAS systems measured SO<sub>2</sub> in the flight direction and at ±40 mrad (2.3°) angles relative to it in both, horizontal and vertical directions. The approaches started at up to 25 km distance to the plume and SO<sub>2</sub> was measured at all times well above the detection limit. In combination with radiative transfer studies, this study indicates that an extended volcanic cloud with a concentration of 10<sup>12</sup> molecules cm<sup>−3</sup> at typical flight levels of 10 km can be detected unambiguously at distances of up to 80 km away. This range provides enough time (approx. 5 min) for pilots to take action to avoid entering a volcanic cloud in the flight path, suggesting that this technique can be used as an effective aid to prevent dangerous aircraft encounters with potentially ash rich volcanic clouds
Acceptance of covid-19 vaccination in the elderly: A cross-sectional study in Southern Italy
In Italy, at the end of 2020, a voluntary immunization plan against COVID-19 was in-troduced, involving elderly among the first target categories. The aim of this study was to assess, through an online questionnaire, the acceptance of COVID-19 vaccination in a sample of older adults from southern Italy. Of a total of 1041 respondents (41.7% males, mean age 76.6 ± 6.5), 965 (92.7%) were vaccinated or willing to be vaccinated against COVID-19, although less than half of the sample was favorable to vaccinations and agreed with mandatory immunization. Acceptance of COVID-19 vaccination was found to be positively related with higher educational level (OR = 1.875, CI95% = 1.113â3.161; p = 0.018) and having social/mass media as a main source of information (OR = 2.415 CI95% = 1.358â4.296, p = 0.003). On the contrary, an inverse relationship was found between acceptance of COVID-19 vaccination and having fulfilled the questionnaire after the intro-duction of green pass (OR = 0.218, CI95% = 0.129â0.369; p < 0.001). Therefore, although this evidence needs to be further confirmed, it is possible to agree with previous studies reporting that compulsory measures, such as green pass implementation, must be accompanied by effective education and information strategies of the target population
Knowledge and lifestyle behaviors related to covid-19 pandemic in people over 65 years old from southern Italy
Background: Control measures adopted during the COVID-19 pandemic had a considerable impact on human daily life and lifestyles. Adherence to the recommended measures is influenced by knowledge and attitudes towards the disease. This cross-sectional study aimed to assess the level of knowledge regarding COVID-19, the related control measures, and lifestyle behaviors adopted during the pandemic in a sample of elderly Italian people. Methods: A web-based questionnaire investigating socio-demographic characteristics, knowledge of COVID-19, the related preventive measures, and lifestyle changes that occurred during the pandemic, were distributed to â„65 years old people living in South Italy. Results: A satisfactory level of knowledge about COVID-19 and the related control measures has been found in the enrolled sample. However, a decrease in physical activity, as well as worsening sleeping and dietary habits, were found in roughly 60% of participants. Females were impacted greater by these lifestyle changes. Conclusions: Participants in this study showed a good level of knowledge regarding COVID-19 and its prevention. Nevertheless, they reported an increase in unhealthy habits that may have important health consequences in the long term and should be addressed by public health interventions targeted at older people
How do Vaccinators Experience the Pandemic? Lifestyle Behaviors in a Sample of Italian Public Health Workers during the COVID-19 Era
Public health workers (PHWs) have experienced substantial workload changes because of their role in managing measures to limit the spread of COVID-19. The studyâs aim was to assess lifestyle changes in Italian PHWs during the pandemic. PHWs attending an annual meeting completed an anonymous questionnaire assessing their sociodemographic and behavioral characteristics and lifestyle changes during the pandemic. A total of 1000 questionnaires were completed. Most participants (63.5% women, mean age 40 ± 13.1 years) were of normal weight (61.5%), non-smokers (81.9%), had a total screen time of â„5 h/day (83.1%), and slept at least 6 h/night (88.7%). Approximately one-third consumed sweet foods every day (30%) and did not engage in physical activity (34.6%). Current sweet food consumption, physical activity, and sleep were associated with changes in these behaviors in the last 2 years (Tau-b = 0.155; Tau-b = â0.175; Tau-b = â0.276, respectively, p < 0.001). An increase in remote working was associated with worse sleep (odds ratio (OR) 2.065, 95% confidence interval (CI) 1.482â2.877) and diet (OR 1.982, 95% CI 1.385â2.838), and increased tablet/PC use (OR 3.314, 95% CI 2.358â4.656). Health promotion measures are needed to support the adoption of healthy lifestyles in this population during the current pandemic
Local barrier dysfunction identified by confocal laser endomicroscopy predicts relapse in inflammatory bowel disease
Loss of intestinal barrier function plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Shedding of intestinal epithelial cells is a potential cause of barrier loss during inflammation. The objectives of the study were (1) to determine whether cell shedding and barrier loss in humans can be detected by confocal endomicroscopy and (2) whether these parameters predict relapse of IBD
- âŠ