A high sensitivity tool for geophysical applications: A geometrically locked Ring Laser Gyroscope

This work demonstrates that a middle size ring laser gyroscope (RLG) can be a very sensitive and robust instrument for rotational seismology, even if it operates in a quite noisy environment. The RLG has a square cavity, $1.60\times 1.60$ m$^2$, and it lies in a plane orthogonal to the Earth rotational axis. The Fabry-Perot optical cavities along the diagonals of the square were accessed and their lengths were locked to a reference laser. Through a quite simple locking circuit, we were able to keep the sensor fully operative for 14 days. The obtained long term stability is of the order of 3~nanorad/s and the short term sensitivity close is to 2~nanorad/s$\cdot$Hz$^{-1/2}$. These results are limited only by the noisy environment, our laboratory is located in a building downtown.Comment: 9 pages, 4 figures, 25 reference

Obesity and sleep disturbance: the chicken or the egg?

Epidemiological studies suggested an association between obesity and sleep disturbances. Obstructive sleep apnea is the most prevalent type of obesity-related sleep disorder that lead to an increased risk for numerous chronic health conditions. In addition the increased visceral adipose tissue might be responsible for the secretion of inflammatory cytokines that could contribute to alter the sleep-wake rhythm. Unhealthy food characterized by high consumption of fat and carbohydrate seems to negatively influence the quality of sleep while diet rich of fiber is associated to more restorative and deeper sleep. Although obesity could cause through several pathogenetic mechanisms an alteration of sleep, it has been reported that subjects suffering from sleep disorders are more prone to develop obesity. Experimental laboratory studies have demonstrated that decreasing either the amount or quality of sleep increase the risk of developing obesity. Experimental sleep restriction also causes physiological, hormonal and food behavioral changes that promote a positive energy balance and a compensatory disproportionate increase in food intake, decrease in physical activity, and weight gain. Thus, the aim of this review is to provide observational evidence on the association of obesity with sleep disturbances and viceversa with emphasis on possible pathophysiological mechanisms (hormonal and metabolic) that link these two pathological conditions

Importance of spinal deformity index in risk evaluation of VCF (vertebral compression fractures) in obese subjects: prospective study.

Introduction Obesity and osteoporosis share many features and recent studies have identified many similarities suggesting common pathophysiological mechanisms. Obesity is associated with a higher risk of non-traumatic fractures despite bone mineral density (BMD) being normal or even increased. Materials and methods 54 obese subjects were analyzed (51 ± 16 years, 10 males, 44 females). Spinal deformity index (SDI) is a semi-quantitative method that may be a surrogate index of bone microarchitecture. SDI index was higher in patients than in controls. In 87.5 % of patients and 10 % of controls we found morphometric vertebral fractures, despite a DEXA Tscore not diagnostic of osteoporosis. Conclusion The objective of this study was to assess in obese patients levels of 25OH vitamin D, parathyroid hormone, serum and urinary calcium (Ca) and phosphorus (P), BMD, and SDI. 87.5 % of the obese subjects present nontraumatic vertebral fractures and reduced bone quality as measured by SDI

Stochastic Operation Optimization of the Smart Savona Campus as an Integrated Local Energy Community Considering Energy Costs and Carbon Emissions

Aiming at integrating different energy sectors and exploiting the synergies coming from the interaction of different energy carriers, sector coupling allows for a greater flexibility of the energy system, by increasing renewables’ penetration and reducing carbon emissions. At the local level, sector coupling fits well in the concept of an integrated local energy community (ILEC), where active consumers make common choices for satisfying their energy needs through the optimal management of a set of multi-carrier energy technologies, by achieving better economic and environmental benefits compared to the business-as-usual scenario. This paper discusses the stochastic operation optimization of the smart Savona Campus of the University of Genoa, according to economic and environmental criteria. The campus is treated as an ILEC with two electrically interconnected multienergy hubs involving technologies such as PV, solar thermal, combined heat and power systems, electric and geothermal heat pumps, absorption chillers, electric and thermal storage. Under this prism, the ILEC can participate in the day-ahead market (DAM) with proper bidding strategies. To assess the renewables’ uncertainties, the roulette wheel method is used to generate an initial set of scenarios for solar irradiance, and the fast forward selection algorithm is then applied to preserve the most representative scenarios, while reducing the computational load of the next optimization phase. A stochastic optimization model is thus formulated through mixed-integer linear programming (MILP), with the aim to optimize the operation strategies of the various technologies in the ILEC, as well as the bidding strategies of the ILECs in the DAM, considering both energy costs and carbon emissions through a multi-objective approach. Case study results show how the optimal bidding strategies of the ILEC on the DAM allow minimizing of the users’ net daily cost, and, as in the case of environmental optimization, the ILEC operates in self-consumption mode. Moreover, in comparison to the current operation strategies, the optimized case allows reduction of the daily net energy cost in a range from 5 to 14%, and the net daily carbon emissions in a range from 6 to 18%

Semi-empirical model for shear strength of RC interior beam-column joints subjected to cyclic loads

This paper proposes an extension to RC interior beam-column joints of a model for the shear strength prediction of exterior joints under seismic actions, already presented in the literature and based, for certain assumptions, on a previous work of Park and Mosalam. The necessary changes, due to the joints\u2019 different physical configurations, only one beam converging in exterior joints and two beams converging in interior ones, are introduced. In the proposed model, on the basis of mechanical considerations, a direct formula for interior joint shear strength accounting for the resisting contributions of three inclined concrete struts and of joint reinforcements, the column horizontal stirrups and intermediate vertical bars, is derived. In comparison to the model for exterior joints, three struts are considered instead of two and the influenced of the upper column axial load on the inclination of the concrete struts is taken into account. The coefficients of the contributions of the struts and reinforcements are calibrated using 69 test data sets available in the literature, selecting only cyclic tests showing joint shear failure. For the validation of the proposed model, the shear strength predictions obtained using the proposed expression are compared with those obtained from Kassem\u2019s model, Wang et al.\u2019s formula and Kim and LaFave\u2019s formula, on a set of 28 specimens. It is also proposed a design formula, whose predictions are compared to those of Eurocode 8 and ACI Code

Somatotropic Axis and Obesity: Is There Any Role for the Mediterranean Diet?

Obesity is associated with reduced spontaneous and stimulated growth hormone (GH) secretion and basal insulin-like growth factor I (IGF-1) levels-which in turn is associated with increased prevalence of cardiovascular risk factors. The aim of this study was to investigate: (1) the association of somatotropic axis with cardiometabolic status; (2) the association of somatotropic axis with the Mediterranean diet and nutritional pattern in people with obesity. Cross-sectional observational study was carried out in 200 adult women, aged 36.98 ± 11.10 years with severe obesity (body mass index-BMI of 45.19 ± 6.30 kg/m2). The adherence to the Mediterranean diet and the total calorie intake was assessed. Anthropometric measurements, body composition and biochemical profile were determined along with Growth Hormone (GH)/Insulin like Growth Factor 1 (IGF-1) axis and insulin resistance (homeostatic model assessment for insulin resistance-HoMA-IR). The enrolled subjects were compared after being divided according to GH peak response and according to IGF-1 standard deviation scores (SDS). Derangements of GH peak were detected in 61.5% of studied patients while IGF-1 deficiency was detected in 71% of the population. Both blunted GH peak response and IGF-1 SDS were indicators of derangements of somatotropic axis and were associated with comparable results in terms of cardiometabolic sequelae. Both GH peak and IGF-1 levels were inversely associated with anthropometric and metabolic parameters. The adherence to the Mediterranean diet predicts GH peak response. Fatty liver index (FLI), fat mass (FM) and phase angle (PhA) were predictive factors of GH peak response as well. In conclusion derangements of somatotropic axis is associated with a worse cardiometabolic profile in people with obesity. A high adherence to the Mediterranean diet-and in particular protein intake-was associated with a better GH status

Phase angle: A possible biomarker to quantify inflammation in subjects with obesity and 25(OH)D deficiency

Obesity is associated to chronic low-grade metabolic inflammation and hypovitaminosis D. Among extra-skeletal effects, an important role in inflammation has been described for vitamin D (25(OH)D). Phase angle (PhA) is a bioelectrical impedance analysis (BIA) parameter that represents an indicator of cellular health in chronic inflammatory states. However, it is still unknown whether a low 25(OH)D levels might correlate with PhA in obesity. Considering the lack of evidence correlating the 25(OH)D levels with PhA in obesity, the aim of this study was to investigate their possible relationship in a group of patients with obesity stratified according to body mass index (BMI) categories. Four hundred and fifty-five adult subjects (219 males and 236 females; 36 ± 11 years) were enrolled. Body composition, including PhA, was assessed using a BIA phase-sensitive system. Serum levels of 25(OH)D was determined by a direct competitive chemiluminescence immunoassay. Most of the participants were affected by grade III obesity (24%) and had 25(OH)D deficiency (67%). Subjects with 25(OH)D deficiency had highest BMI (p 14 ng/mL (p < 0.001). In conclusion, we provided preliminary insights into a novel link between 25(OH)D levels and PhA in the setting of obesity. This association uncovered a new potential usefulness of PhA as expression of cell membrane integrity and predictor of inflammation in low 25(OH)D status that might help in identifying high-risk patients with obesity who could benefit from careful 25(OH)D supplementation

Sex differences of vitamin D status across BMI classes: An observational prospective cohort study

Growing evidence reported that vitamin D deficiency is a common finding in obesity. Vitamin D status also seems to be sex-related, although little is known regarding this association. Therefore, the aim of this study was to investigate the sex-related differences of serum 25OH vitamin D (25OHD) concentrations across body mass index (BMI) classes and, if there were any differences, whether they could be explained by sex-related differences in body composition. We enrolled 500 subjects (250 males, age 37.4 ± 11.8 years; 250 females, age 36.6 ± 11.8 years). Body composition was assessed by bioelectrical impedance analysis (BIA) phase-sensitive system. Serum 25OHD concentration was quantified by a direct, competitive chemiluminescence immunoassay. Vitamin D deficiency was defined as a serum 25OHD concentrations < 20 ng/mL (50 nmol/L). Stratifying the sample population according to sex and BMI categories, 25OHD concentrations were significantly higher in males compared to females in all BMI classes and decreased along with the increase of BMI values. Females with vitamin D deficiency had higher fat mass (FM) % compared to males with vitamin D deficiency. The 25OHD concentrations inversely correlated with FM % in both sexes. In a multiple regression analysis model, sex, FM %, and BMI were predictive factors of 25OHD concentration. In conclusion, our study suggests that 25OHD concentrations were lower in females than males across all BMI categories. Given the tight correlation between 25OHD concentrations and FM %, it can be hypothesized that the lower 25OHD concentrations in females than males can be explained by the fact that females have a higher amount of fat than males