484 research outputs found
Approximation of probability density functions for PDEs with random parameters using truncated series expansions
The probability density function (PDF) of a random variable associated with
the solution of a partial differential equation (PDE) with random parameters is
approximated using a truncated series expansion. The random PDE is solved using
two stochastic finite element methods, Monte Carlo sampling and the stochastic
Galerkin method with global polynomials. The random variable is a functional of
the solution of the random PDE, such as the average over the physical domain.
The truncated series are obtained considering a finite number of terms in the
Gram-Charlier or Edgeworth series expansions. These expansions approximate the
PDF of a random variable in terms of another PDF, and involve coefficients that
are functions of the known cumulants of the random variable. To the best of our
knowledge, their use in the framework of PDEs with random parameters has not
yet been explored
Environmental and economic benefits from the phase-out of residential oil heating: A study from the Aosta Valley region (Italy)
Although its use is declining, oil heating is still used in areas not covered by the methane grid. Oil heating is becoming more and more expensive, requires frequent tank refill operations, and has high emissions of greenhouse gas (GHG) and air pollutants such as SOx. In addition, spills from oil underground storage tanks (USTs) represent a serious environmental threat to soil and groundwater quality. In this paper, we present a comprehensive analysis on technical alternatives to oil heating with reference to the Aosta Valley (NW Italy), where this fuel is still often used and numerous UST spills have been reported in the last 20 years. We assess operational issues, GHG and pollutant emissions, and unit costs of the heat produced for several techniques: LPG boilers, wood boilers (logs, chips, pellets) and heat pumps (air-source, geothermal closed-loop and open-loop systems). We examine the investment to implement such solutions in two typical cases, a detached house and a block of flats, deriving payback times of about 3â8 years. Wood log boilers turn out to be the most economically convenient solutions; however, heat pumps provide several benefits from the operational and environmental points of view. In addition, including solar thermal panels for domestic hot water or a photovoltaic plant would have payback times of about 6â9 years. The results highlight the economic feasibility and the multiple benefits of a rapid phase-out of oil heating in Italy
Whole-Body Cryostimulation in Fibromyalgia: A Scoping Review
Currently, all available therapies for the control and management of fibromyalgia (FM) are mostly focused on relieving patientsâ symptoms and improving their quality of life. The purpose of this review is to provide an up-to-date overview of the evidence supporting the beneficial effects of whole-body cryostimulation (WBC) in patients with FM and evidence-based guidance on the possible adjuvant use of WBC in the treatment of FM. We searched the most recent literature by retrieving 10 eligible studies, 4 of which were abstracts only, from a total of 263 records. Thermal stress caused by cryostimulation induces an analgesic effect, improving pain, redox balance, and inflammatory symptoms in an exercise-mimicking fashion. In addition, it reduces the feeling of fatigue, improves mood, and reduces mental health deterioration with positive consequences on depressive states and improved sleep quality. Although the studies included in this review are not of sufficient quality and quantity to draw definitive conclusions about the effectiveness of WBC in FM, initial evidence indicates WBC as a promising add-on option in the multidisciplinary treatment of FM, due to its rapid action and high patientsâ compliance. The application of WBC protocols has the potential to expand therapeutic options for the treatment of FM and related disorders; however, larger, high-quality primary studies are still needed
Extensive carrier testing and CF birth prevalence: evidence for a negative correlation
Aim of the study was to evaluate if extensive CF carrier testing may be connected
with the progressive decrease of CF birth incidence recorded in North Eastern Italy.
From 1993 to 2007 an average 52,000 newborns per year underwent Neonatal
Screening (NS), and 198 newborns with CF were detected (1/3937). A time related
contraction in birth prevalence was confirmed, with an average annual percent
decrease of 0.15 per 10,000 neonates (Poisson regression analysis p 0.003). In
the NS area two sections were identified: the Western Region (WR), where CF
carrier testing is not offered to couples from the general population, and the
Eastern Region (ER), where CF carrier testing is widely offered to couples from
the general population. In ER from 1995 to 2007 such testing practice has been
steadily expanding, with a total of 87,721 CF carrier tests performed, 3460 carriers
identified, and 238 carrier couples detected (data collection in progress). The
prevalence of CF decreased by time (p<0.001) but the rate of decrease was more
enhanced in ER as suggested by the existence of a statistically significant (p = 0.014)
interaction term between time and region in the Poisson regression model. The
overall negative trend in North Eastern Italy is due to a contraction of CF births
in its Eastern part. In ER a negative correlation was found between CF incidence
and the number of carrier tests (p 0.012). Prenatal diagnosis data collection is in
progress. These data support the hypothesis that carrier screening may modify the
incidence of CF
Long maximal incremental tests accurately assess aerobic fitness in class II and III obese men.
This study aimed to compare two different maximal incremental tests with different time durations [a maximal incremental ramp test with a short time duration (8-12 min) (STest) and a maximal incremental test with a longer time duration (20-25 min) (LTest)] to investigate whether an LTest accurately assesses aerobic fitness in class II and III obese men. Twenty obese men (BMIâ„35 kg.m-2) without secondary pathologies (mean±SE; 36.7±1.9 yr; 41.8±0.7 kg*m-2) completed an STest (warm-up: 40 W; increment: 20 W*min-1) and an LTest [warm-up: 20% of the peak power output (PPO) reached during the STest; increment: 10% PPO every 5 min until 70% PPO was reached or until the respiratory exchange ratio reached 1.0, followed by 15 W.min-1 until exhaustion] on a cycle-ergometer to assess the peak oxygen uptake [Formula: see text] and peak heart rate (HRpeak) of each test. There were no significant differences in [Formula: see text] (STest: 3.1±0.1 L*min-1; LTest: 3.0±0.1 L*min-1) and HRpeak (STest: 174±4 bpm; LTest: 173±4 bpm) between the two tests. Bland-Altman plot analyses showed good agreement and Pearson product-moment and intra-class correlation coefficients showed a strong correlation between [Formula: see text] (r=0.81 for both; pâ€0.001) and HRpeak (r=0.95 for both; pâ€0.001) during both tests. [Formula: see text] and HRpeak assessments were not compromised by test duration in class II and III obese men. Therefore, we suggest that the LTest is a feasible test that accurately assesses aerobic fitness and may allow for the exercise intensity prescription and individualization that will lead to improved therapeutic approaches in treating obesity and severe obesity
Does Kinesiophobia Mediate the Relationship between Pain Intensity and Disability in Individuals with Chronic Low-Back Pain and Obesity?
Individuals suffering from chronic low-back pain and obesity face severe physical and functional limitations. According to the fear-avoidance model, kinesiophobia might play a crucial role in the relationship between pain intensity and disability. Thus, the purpose of this study was to verify the role of kinesiophobia as a mediator in the association between pain intensity and disability in individuals with both chronic low-back pain and obesity. A total of 213 individuals with chronic low-back pain and obesity were included in the study. The level of kinesiophobia, pain intensity and disability were all assessed using self-reported questionnaires. We verified through a simple mediation analysis that kinesiophobia partially mediated the association between pain intensity and disability in our sample. According to our findings, we emphasize the crucial role of kinesiophobia as a psychological factor that should be addressed in chronic low-back pain rehabilitative protocols to reduce disability in individuals with obesity
Sensory integration and response to balance perturbation in overweight physically active individuals
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