Shared attention in virtual immersive reality enhances electrophysiological correlates of implicit sensory learning.

Shared attention effects on learning and memory demonstrate that experiences are amplified when we are not alone. Virtual reality poses new challenges to the study of co-presence. Above all, is coattending together with someone else's avatar in an immersive VR setting comparable with shared experiences at a neural processing level? In the present study we investigate shared attention effects in VR for the first time. We recorded mismatch negativities (MMN) during an auditory roving paradigm, a well-known index of implicit perceptual learning. EEG responses to deviant and standard sounds were registered while subjects were alone (Solo condition) or together (Other condition) with a virtual avatar (Virtual scenario) or physically present confederate (Physical scenario). We found an overall main effect of co-presence on MMN revealed by a point-by-point 2 × 2 ANOVA, thereby replicating previous studies on physical co-presence. Additionally, we found no significant interaction between the scenario (Physical vs. Virtual) and co-presence (Solo vs. Other). Our results indicate that virtual immersive co-presence mimics physical co-presence.

The Impact of Smoking on Bone Metabolism, Bone Mineral Density and Vertebral Fractures in Postmenopausal Women.

BACKGROUND: Smoking is recognized among the risk factors for osteoporosis, but only few studies have comprehensively explored its influence on bone metabolism and strength. We aimed to evaluate smoking effects on calcium-phosphate metabolism, bone mineral density (BMD) and fracture risk in postmenopausal women. METHODS: Our sample included 1067 postmenopausal women who arrived to our osteoporosis outpatient clinic. Anamnestic data, smoking habits (categorized as never, former, and current; and by smoking intensity and duration), biochemical parameters, lumbar/femoral BMD, and presence of vertebral fractures were recorded. In a subsample of 357 women, the changes in BMD after a 2-yr follow-up period were also assessed. RESULTS: Current smokers had shorter reproductive age, lower body mass index, and higher prevalence of heavy alcohol consumption than former/never smokers. They also had lower PTH values and weaker linear association between serum vitamin D and parathyroid hormone (current ß = -0.11[SE = 0.004]; former ß = -0.14[SE = 0.01]; never ß = -0.20[SE = 0.003]; p < 0.01 for all). Baseline BMD did not reflect differences based on smoking habits, duration or intensity. However, after 2 years, only current smokers significantly worsened in femural BMD. After adjustment for confounders, the chance of having sustained vertebral fractures at the first evaluation increased by 74% (95% confidence interval:1.07-2.83) in current compared with never smokers, especially among heavy smokers. CONCLUSIONS: Smoking may negatively affect bone by inhibiting vitamin D-parathyroid hormone axis, reducing estrogen exposure, promoting risky health behaviors, and accelerating bone loss, especially at the femur. No significant differences were observed in these outcomes among former smokers, suggesting that quitting smoking has beneficial effects on bone health.

Parathormone, vitamin D and the risk of atrial fibrillation in older adults: A prospective study.

BACKGROUND & AIMS: Vitamin D and parathormone (PTH) have been associated with cardiovascular outcomes, but their impact on atrial fibrillation (AF) onset is still unclear. We explored the influence of serum 25-hydroxyvitamin D (25[OH]D) and PTH on AF risk in older adults. METHODS AND RESULTS: Data come from 2418 participants enrolled in the Progetto Veneto Anziani study. Serum 25(OH)D and intact PTH were measured using radioimmunoassay and two-site immunoassay, respectively. The associations between 25(OH)D, PTH and adjudicated AF cases over 4-years were explored by Cox regression. Over the follow-up, 134 incident cases of AF were assessed. The incidence rate of the sample was 13.5 (95%CI 11.4-15.9) per 1000 person-years, and was higher among those with high PTH levels (high: 16.4 [95%CI 11.3-24.0] per 1000 person-years), especially when associated to low 25(OH)D (20.3 [95%CI 12.9-32.3] per 1000 person-years). At Cox regression, only high PTH was significantly associated to an increased risk of AF (HR = 1.90, 95%CI 1.27-2.84). A marginal significant interaction (p = 0.06) was found between 25[OH]D and PTH concentrations in influencing AF risk. When exploring the risk of AF for combined categories of 25(OH)D and PTH, we found that those with high PTH and low 25(OH)D levels had an AF risk twice as high as that of people with normal values (HR = 2.09, 95%CI 1.28-3.42). CONCLUSION: The risk of AF may be increased by high PTH levels, especially when associated with 25(OH)D deficiency. The identification and treatment of high PTH or vitamin D deficiency may thus contribute to lower the risk of AF.

Phase angle and metabolic equivalents as predictors of frailty transitions in advanced age.

OBJECTIVES: The aim of this prospective study was to investigate whether two cellular and metabolic health indices, phase angle (PhA) and metabolic equivalents (METs), can predict changes in frailty states in fit community-dwelling older people. METHODS: A sample of 118 individuals aged ≥65 years who attended a twice-weekly mild fitness program of aerobic and/or resistance exercises was enrolled in the study. At baseline and after three years, individuals underwent a clinical examination, biochemical determinations, bioelectrical impedance analysis, body composition assessment with dual energy X-ray absorptiometry, physical performance tests, and frailty and sarcopenia assessment. In 78 participants was executed indirect calorimetry, too. Based on frailty transitions during the follow-up between non-frailty, pre-frailty and frailty, participants were categorized as improved, stable (non-frail or pre-frail), and worsened or remaining frail. The chances to experience different frailty changes by baseline PhA and METs were explored through multinomial regression analysis and expressed as odds ratios (OR) and 95% Confidence intervals (95%CI). RESULTS: During the follow-up, 8 participants improved in frailty status, 84 were stable and 26 worsened or remained frail. For each one-unit increase in PhA, the odds of improving in frailty increased by 4.53 times (95%CI:1.18-17.46); while for each one-unit increase in METs, the odds of worsening in frailty decreased by 65% (95%CI:0.16-0.79). CONCLUSIONS: PhA and METs may be indirect measures of functional reserve, with lower values being potential biomarkers of evolving frailty.

The Effect of Different Compatibilizers on the Properties of a Post-Industrial PC/PET Blend.

The substitution of virgin resins by recycled ones is a worldwide tendency that is supported by the fluctuation of oil prices and the transition to a circular economy. Polymeric blends have been intensively studied because of their ability to provide tailored properties for particular applications. However, in their design phases, the issue of end-life re-use had not been well addressed, and now difficulties in their recycling are arising. In this study, we investigated the effect of three different compatibilizers: two chain extenders (CEs), (1) a styrene-acrylic oligomer (ESAo), and (2) methylene diphenyl diisocyanate (MDI) and an impact strength modifier, (3) an ethylene copolymer (EMAco), for the recycle of a post-industrial polycarbonate/polyethylene terephthalate (PC/PET) blend. The materials were prepared by reactive extrusion and characterized by intrinsic viscosity (IV) measurements, mechanical tests, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy analysis (FTIR), and transmission electron microscopy (TEM). The introduction of each additive has been demonstrated to improve the compatibility between PET and PC in the post-industrial blend, leading to enhanced mechanical properties. The IV measurements increased to values that were comparable to the virgin material. In addition, CEs affected the crystallization of PET (as they reduced the degree of crystallinity), while EMAco acted as a nucleating agent. Morphological analysis enabled confirming the compatibilization effects induced by the tested additives.

Influence of serum 25-hydroxyvitamin D levels, fat-free mass, and fat mass on bone density, geometry and strength, in healthy young and elderly adults.

PURPOSE: The association between serum 25-hydroxyvitamin D (25-OHD) levels and cortical/trabecular bone parameters has been explored in the elderly, but less so in younger adults; body composition may also influence bone parameters across the life span. We aimed to investigate, with peripheral quantitative computerized tomography (pQCT), the relationship between serum 25-OHD levels and bone geometry and strength and, at the same time, to explore the influence of fat mass and fat-free mass on bone parameters, for the tibia and radius, in healthy young and elderly adults. METHODS: The study involved 149 healthy adults grouped by age: 65 were under 65 years old, and 84 were older. All participants were assessed in terms of: clinical history; serum 25-OHD levels; fat-free mass (FFM) and fat mass (FM), measured with DXA; total and cortical bone cross-sectional area (CSA, CSAc), and trabecular and cortical bone mineral density (BMDt, BMDc); and fracture load x and y for the tibia and radius, measured with pQCT. RESULTS: In the younger group, the association between 25-OHD levels and bone parameters did not remain as significant for any parameters after multivariate adjustment. In the elderly, 25-OHD correlated with CSAc (partial R2 = 0.33), fracture load x (partial R2 = 0.54), and fracture load y (partial R2 = 0.46) for the radius, and marginally with BMDt (partial R2 = 0.09; B-H adjusted p < 0.05 for all) for the tibia. FFM correlated with all bone parameters in both age groups. In the elderly group alone, FM correlated with BMDt at the tibia (r = 0.25, p < 0.05), with CSA at both sites (radius r = -0.25, p < 0.05; tibia r = -0.32, p < 0.001), and with fracture load y on the radius (r = -0.22, p < 0.05). CONCLUSION: While serum 25-OHD levels correlated only weakly with bone parameters in younger adults, a significant relationship was observed for elderly people. Fat-free mass showed positive simple correlation with pQCT-derived bone parameters in both age groups except with BMDc in the younger group. Further longitudinal studies are needed to clarify these relationships.