1,581 research outputs found
The capability of capacitive sensors in the monitoring relative humidity in hypogeum environments
Hypogeum environments are characterized by high levels of relative humidity (RH).
Most humidity sensors currently in use are based on the capacitive effect of the dielectric material
to change according to water vapour uptake. In hypogeum environments the dielectric material
can be saturated by water vapor, implying a significant error in the RH measurement. To improve
the capacity of this type of humidity sensors, a modified hygrometer capacitive sensor, which
uses a heating cycle to avoid the condensation, has been recently developed by Rotronic®.
During four field campaigns in two different hypogea environments (the Monkey Tomb in Siena
and the Mithreum of Caracalla Baths in Rome), RH was measured using the conventional
capacitive sensor (CCS) and the heated capacitive sensor (HCS). The purpose of this study was
to investigate the capability of HCS to detect RH variations when the environmental conditions
were close to vapor saturation. Significant differences were found between the measurements of
the two sensors: when RH was close to 100%, the CCS was not able to detect the RH decrease,
giving only a measure of RH=100%, while HCS detected such a RH decrease. Therefore, these
results encourage the use of HCS in the monitoring of RH levels in extreme humidity sites such
as hypogea sites
CleAir monitoring system for particulate matter. A case in the Napoleonic Museum in Rome
Monitoring the air particulate concentration both outdoors and indoors is becoming a more relevant issue in the past few decades. An innovative, fully automatic, monitoring system called CleAir is presented. Such a system wants to go beyond the traditional technique (gravimetric analysis), allowing for a double monitoring approach: the traditional gravimetric analysis as well as the optical spectroscopic analysis of the scattering on the same filters in steady-state conditions. The experimental data are interpreted in terms of light percolation through highly scattering matter by means of the stretched exponential evolution. CleAir has been applied to investigate the daily distribution of particulate matter within the Napoleonic Museum in Rome as a test case
Systematic review and meta-analysis of randomised controlled trials on the effects of potassium supplements on serum potassium and creatinine
Objectives: High potassium intake could prevent stroke, but supplementation is considered hazardous. We assessed the effect of oral potassium supplementation on serum or plasma potassium levels and renal function.
Setting: We updated a systematic review of the effects of potassium supplementation in randomised clinical trials carried out worldwide, published in 2013, extending it to July 2015. We followed the PRISMA guidelines.
Participants: Any individual taking part in a potassium supplementation randomised clinical trial. Studies included met the following criteria: randomised clinical trials, potassium supplement given and circulating potassium levels reported.
Intervention: Oral potassium supplementation.
Primary outcome measures: Serum or plasma potassium and serum or plasma creatinine.
Results: A total of 20 trials (21 independent groups) were included (1216 participants from 12 different countries). All but 2 were controlled (placebo n=16, control n=2). Of these trials, 15 were crossover, 4 had a parallel group and 1 was sequential. The duration of supplementation varied from 2 to 24 weeks and the amount of potassium given from 22 to 140 mmol/day. In the pooled analysis, potassium supplementation caused a small but significant increase in circulating potassium levels (weighted mean difference (WMD) 0.14 mmol/L, 95% CI 0.09 to 0.19, p<1×10−5), not associated with dose or duration of treatment. The average increase in urinary potassium excretion was 45.75 mmol/24 hours, 95% CI 38.81 to 53.69, p<1×10−5. Potassium supplementation did not cause any change in circulating creatinine levels (WMD 0.30 µmol/L, 95% CI −1.19 to 1.78, p=0.70).
Conclusions: In short-term studies of relatively healthy persons, a moderate oral potassium supplement resulted in a small increase in circulating potassium levels and no change in renal function
Genetic variants of Y chromosome are associated with a protective lipid profile in black men
Objective— Gender and ethnicity modulate the phenotypic expression of cardiovascular risk factors. In particular, men are at higher risk of developing cardiovascular diseases compared to women, whereas black populations of African origin display reduced mortality from coronary heart disease (CHD) as compared to both whites and South Asians. Because the male-specific region (MSY) of the human Y chromosome is an obvious candidate for gender-related differences in the development of cardiovascular diseases, we aimed to identify genetic variants of MSY influencing cardiovascular risk profile in different ethnic groups.
Methods and Results— We genotyped 4 polymorphisms of MSY (HindIII±, rs768983 of TBL1Y, rs3212292 of USP9Y, and rs9341273 of UTY genes) in 579 men of different ethnic groups (blacks, South Asians, and whites) from UK and in 301 whites in Italy. We found that the TBL1YA USP9YA haplotype, present only in blacks in whom it represents the most frequent allelic combinations (AA: n=125; all other combinations: n=45), was associated with lower levels of triglycerides (P=0.025) and higher levels of HDL-cholesterol (P=0.005) as compared to the other haplotypes.
Conclusion— The TBL1YA USP9YA haplotype of the Y chromosome, present only in black people of African origin, attributes a favorable lipoprotein pattern, likely to contribute to their reduced susceptibility to coronary heart disease.
The study evaluated the association of genetic variants of the male-specific region of the Y chromosome with cardiovascular risk factors in different ethnic groups. The most frequently observed haplotype in black people was associated with a favorable lipoprotein pattern, thus contributing to the lower rate of cardiovascular diseases in blacks
Personal UV exposure on a ski-field at an alpine site
International audienceMountain sites experience enhanced ambient UV radiation levels due to the concurrent effects of shorter radiation path-length, low aerosol load and high reflectivity of the snow surfaces. This study was encouraged by the possibility to collect data of personal UV exposure in the mountainous areas of Italy, for the first time. Personal UV exposure (expressed in terms of Exposure Ratio, ER) of two groups of volunteers (ski instructors and skiers) at the Alpine site of La Thuile (Valle d'Aosta region, Italy) was assessed using polysulphone dosimetry which was tested in a mountainous snow-covered environment. In addition measurements of biological markers of individual response to UV exposure such as skin colorimetric parameters were carried out. It was found that snow and altitude of study site affect calibration curves of polysulphone dosimeters in comparison to a situation without snow. The median ER, taking into account the whole sample, is 0.60 in winter, with a range of 0.29 to 1.46, and 1.02 in spring, ranging from 0.46 to 1.72. There are no differences in exposures across skiers and instructors in spring while in winter skiers experience lower values. UV exposures are not sensitive to the use of sunscreen across instructor/skier group by day or by seasons or by photo-type. With regard to colorimetric parameters, the main result was that both skiers and instructors had on average significantly lower values of L* and b* after exposure i.e. becoming darker but the inappropriate sunscreen use did not reveal any changes in skin colorimetric parameters except in one spring day. In conclusions UV intensities on the ski-fields are often significantly higher than those on horizontal surfaces. Given the high levels of exposure observed in the present study, dedicated public heath messages on the correct sunscreen use should be adopted
Blood cells as a source of transcriptional biomarkers of childhood obesity and its related metabolic alterations: results of the IDEFICS Study
Background: IDEFICS (Identification and Prevention of Dietary-and Lifestyle-Induced Health Effects in Children and Infants Project) is a European multicenter study on childhood obesity. One of its goals is to define early biomarkers of risk associated with obesity and its comorbid conditions.
Objective: We considered blood cells as a new potential source of transcriptional biomarkers for these metabolic disorders and examined whether blood cell mRNA levels of some selected genes (LEPR, INSR, CPT1A, SLC27A2, UCP2, FASN, and PPAR alpha) were altered in overweight children and whether their expression levels could be defined as markers of the insulin-resistant or dyslipidemic state associated with overweight.
Design: Blood samples were obtained from 306 normal-weight and overweight children, aged 2-9 yr, from eight different European countries. Whole-blood mRNA levels were assessed by quantitative RT-PCR.
Results: LEPR, INSR, and CPT1A mRNA levels were higher in overweight compared with normal-weight children (the two latter only in males), whereas SLC27A2 mRNA levels were lower in overweight children. Significant associations were also found between expression levels of LEPR, INSR, CPT1A, SLC27A2, FASN, PPAR alpha, and different parameters, including body mass index, homeostasis model assessment index, and plasma triglycerides and cholesterol levels. These associations showed that high expression levels of CPT1A, SLC27A2, INSR, FASN, or PPAR alpha may be indicative of a lower risk for the insulin-resistant or dyslipidemic state associated with obesity, whereas low LEPR mRNA levels appear as a marker of high low-density lipoprotein cholesterol, independently of body mass index.
Conclusions: These findings point toward the possibility of using the expression levels of these genes in blood cells as markers of metabolic status and can potentially provide an early warning of a future disorder
High-sensitivity C-reactive protein is a predictive factor of adiposity in children : results of the Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and InfantS (IDEFICS) study
Background-Whereas cross-sectional studies have shown that obesity is associated with increased C-reactive protein (CRP) levels in children, little is known about the impact of low-grade inflammation on body mass changes during growth.
Methods and Results-We assessed cross-sectionally and longitudinally the association of high-sensitivity (hs)-CRP levels with overweight/obesity and related cardiometabolic risk factors in the Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and InfantS (IDEFICS) cohort. 16 224 children from 8 European countries (2 to 9 years) were recruited during the baseline survey (T0). After the exclusion of 7187 children because of missing hs-CRP measurements and 2421 because of drug use during the previous week, the analysis was performed on 6616 children (Boys=3347; Girls=3269; age=6.3 +/- 1.7 years). Of them, 4110 were reexamined 2 years later (T1). Anthropometric variables, blood pressure, hs-CRP, blood lipids, glucose and insulin were measured. The population at T0 was divided into 3 categories, according to the baseline hs-CRP levels. Higher hs-CRP levels were associated with significantly higher prevalence of overweight/obesity, body mass index (BMI) z-score and central adiposity indices (P values all <0.0001), and with higher blood pressure and lower HDL-cholesterol levels. Over the 2-year follow-up, higher baseline hs-CRP levels were associated with a significant increase in BMI z-score (P<0.001) and significantly higher risk of incident overweight/obesity.
Conclusions-Higher hs-CRP levels are associated to higher body mass and overweight/obesity risk in a large population of European children. Children with higher baseline levels of hs-CRP had a greater increase in BMI z-score and central adiposity over time and were at higher risk of developing overweight/obesity during growth
A Digital Pattern Methodology supporting Railway Industries in Portfolio Management
The object of this paper is the development of a decision support system involved in
the bidding for invitations to tender in the railway field. The proposed methodology
is based on the characterization of the whole train and its components, through
several attributes according to a digital pattern approach. In particular some key
components were chosen such as the traction motor, the bogie and the auxiliary
equipment converter. The system measures the extent to which the products offered
by the company fit the one required by the customer, comparing the homologous
attributes. Such analysis is called ‘adopt/adapt/innovate’ (AAI). In this way it is
possible to identify products already designed that fully or partly fit what required,
obtaining huge benefits in terms of effectiveness and efficiency
Z-extremization and F-theorem in Chern-Simons matter theories
The three dimensional exact R symmetry of N=2 SCFTs extremizes the partition
function localized on a three sphere. Here we verify this statement at weak
coupling. We give a detailed analysis for two classes of models. The first one
is an SU(N)_k gauge theory at large k with both fundamental and adjoint matter
fields, while the second is a flavored version of the ABJ theory, where the CS
levels are large but they do not necessarily sum up to zero. We study in both
cases superpotential deformations and compute the R charges at different fixed
points. When these fixed points are connected by an RG flow we explicitly
verify that the free energy decreases at the endpoints of the flow between the
fixed points, corroborating the conjecture of an F-theorem in three dimensions.Comment: 28 pages, 3 figures, JHEP.cls, minor corrections, references adde
Chemical composition of copaíba oilresin from the Porto Dias and Santa Quitéria extractive settlement projects, in Acre.
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