Improved crack resistance and thermal conductivity of cubic zirconia containing graphene nanoplatelets

Composites of 8 mol.% yttria-stabilized zirconia (8YSZ) with graphene nanoplatelets (GNP) have been pointed as alternative interconnectors in SOFC due to their mixed ionic-electronic conduction. Here we show that GNP addition provides rising crack-resistance behavior, with long crack toughness up to 78% higher than that of 8YSZ, also improving its thermal conductivity (up to 6 times for the in-plane direction). Toughness versus crack length is measured for 7 and 11 vol.% of GNP using single edge V-notched beam technique and ultrashort pulsed laser notching; and thermal behavior is analyzed by the laser flash method. Materials also have highly anisotropic coefficient of thermal expansion. These properties contribute to enhance their performance under the harsh operating conditions of SOFC, as thermal residual stresses could be reduced while significantly improving the system mechanical stability. Moreover, the heat transfer may be enhanced especially along the interface direction which would increase the system efficiency.This work was supported by Spanish project RTI2018-095052-B-I00, Ministerio de Ciencia, Innovacion y Universidades, Spain (MCIU/AEI/FEDER, UE). AG and PM acknowledge support from Ministerio de Economía, Industria y Competitividad, Spanish government (Project FIS2017- 87970-R) and Junta de Castilla y León, Spain (Project SA287P18). C. R. thanks the financial support by MCIU under contract IJCI-2017-34724 of “Juan de la Cierva” Program

Bone strength index at Tibia and standing broad jump in adolescent swimmers

Measurement of broad jump is a simple, economical and non-invasive test that provides valuable information on muscular strength and power in youth lower limbs,and has been shown to be related to bone health..

Validity of a food-frequency questionnaire for estimating calcium intake in adolescent swimmers

Introduction: accurate estimates of the intake of specific nutrients such as calcium (Ca) are crucial to correctly rank or classify subjects in the distribution of intakes. Therefore, we aimed to estimate the relative validity of a food frequency questionnaire (FFQ) for measuring Ca intake in two different groups of healthy adolescents, a normoactive control group and a physically active group of swimmers with 2 non-consecutive 24h recalls (2 x 24HR) collected as the reference method. Methods: Pearson correlations, agreement between the 24HR and the FFQ at an individual level and questionnaire’s ability to assign individuals to the same quartile of intake as the 24HR were calculated. Results: mean daily Ca intakes were 564.6 mg (SD 232.0) and 895.9 mg (SD 343.1) for the 2 x 24HR and FFQ respectively in controls (P < 0.001); and 731.9 mg (SD 299.8) and 979.8 mg (SD 408.5) for the 2 x 24HR and FFQ respectively in swimmers (P < 0.001). Pearson correlations were 0.52 for controls and 0.47 for swimmers after correcting for intra-variability. Cross-classification analysis indicated that 73.7% of controls and 63.1% of swimmers were classified correctly or in the adjacent category. Also, the 89% of the control group and 79% of swimmers were classified correctly with the FFQ according to the dietary reference intake (DRI) of 1300 mg/d. Conclusions: for both groups, the FFQ tended to overestimate Ca intake, however it demonstrated fairly good ability to classify subjects into extremes of Ca intake and identified adolescents having Ca intakes lower than the dietary reference intake

Association Between Physical Fitness and Bone Strength and Structure in 3- to 5-Year-Old Children

Background: The positive association between physical fitness and bone structure has been widely investigated in children and adolescents, yet no studies have evaluated this influence in young children (ie, preschoolers). Hypothesis: Fit children will present improved bone variables when compared with unfit children, and no sex-based differences will emerge in the sample. Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: Handgrip strength, standing long jump (SLJ), speed/agility, balance, and cardiorespiratory fitness (CRF) were assessed using the Assessing FITness levels in PREschoolers (PREFIT) test battery in 92 children (50 boys; age range, 3-5 years). A peripheral quantitative computed tomography scan was performed at 38% of the length of the nondominant tibia. Cluster analysis from handgrip strength, SLJ, speed/agility, and CRF was developed to identify fitness groups. Bone variables were compared between sexes and between cluster groups. The association between individual physical fitness components and different bone variables was also tested. Results: Three cluster groups emerged: fit (high values on all included physical fitness variables), strong (high strength values and low speed/agility and CRF), and unfit (low strength, speed/agility, and CRF). The fit group presented higher values than the strong and unfit groups for total and cortical bone mineral content, cortical area, and polar strength strain index (all P < 0.05). The fit group also presented a higher cortical thickness when compared with the unfit group (P < 0.05). Handgrip, SLJ, and speed/agility predicted all bone variables except for total and cortical volumetric bone mineral density. No differences were found for bone variables between sexes. Conclusion: The results suggest that global fitness in preschoolers is a key determinant for bone structure and strength but not volumetric bone mineral density. Clinical Relevance: Physical fitness is a determinant for tibial bone mineral content, structure, and strength in very young children. Performing physical fitness tests could provide useful information related to bone health in preschoolers

Uncovering Ecosystem Service Bundles through Social Preferences

Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem’s capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem’s capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs

Associations between eating speed, diet quality, adiposity, and cardiometabolic risk factors

Objective: To assess the associations between eating speed, adiposity, cardiometabolic risk factors, and diet quality in a cohort of Spanish preschool-children. Study design: A cross-sectional study in 1371 preschool age children (49% girls; mean age, 4.8 ± 1.0 years) from the Childhood Obesity Risk Assessment Longitudinal Study (CORALS) cohort was conducted. After exclusions, 956 participants were included in the analyses. The eating speed was estimated by summing the total minutes used in each of the 3 main meals and then categorized into slow, moderate, or fast. Multiple linear and logistic regression models were fitted to assess the β-coefficient, or OR and 95% CI, between eating speed and body mass index, waist circumference, fat mass index (FMI), blood pressure, fasting plasma glucose, and lipid profile. Results: Compared with participants in the slow-eating category, those in the fast-eating category had a higher prevalence risk of overweight/obesity (OR, 2.9; 95% CI, 1.8-4.4; P < .01); larger waist circumference (β, 2.6 cm; 95% CI, 1.5-3.8 cm); and greater FMI (β, 0.3 kg/m2; 95% CI, 0.1-0.5 kg/m2), systolic blood pressure (β, 2.8 mmHg; 95% CI, 0.6-4.9 mmHg), and fasting plasma glucose levels (β, 2.7 mg/dL, 95% CI, 1.2-4.2 mg/dL) but lower adherence to the Mediterranean diet (β, −0.5 points; 95% CI, −0.9 to −0.1 points). Conclusions: Eating fast is associated with higher adiposity, certain cardiometabolic risk factors, and lower adherence to a Mediterranean diet. Further long-term and interventional studies are warranted to confirm these associations

Dietary animal and plant protein intakes and their associations with obesity and cardio-metabolic indicators in European adolescents: The HELENA cross-sectional study

Background: Previous studies suggest that dietary protein might play a beneficial role in combating obesity and its related chronic diseases. Total, animal and plant protein intakes and their associations with anthropometry and serum biomarkers in European adolescents using one standardised methodology across European countries are not well documented. Objectives: To evaluate total, animal and plant protein intakes in European adolescents stratified by gender and age, and to investigate their associations with cardio-metabolic indicators (anthropometry and biomarkers). Methods: The current analysis included 1804 randomly selected adolescents participating in the HELENA study (conducted in 2006-2007) aged 12.5-17.5 y (47% males) who completed two non-consecutive computerised 24-h dietary recalls. Associations between animal and plant protein intakes, and anthropometry and serum biomarkers were examined with General linear Model multivariate analysis. Results: Average total protein intake exceeded the recommendations of World Health Organization and European Food Safety Authority. Mean total protein intake was 96 g/d (59% derived from animal protein). Total, animal and plant protein intakes (g/d) were significantly lower in females than in males and total and plant protein intakes were lower in younger participants (12.5-14.9 y). Protein intake was significantly lower in underweight subjects and higher in obese ones; the direction of the relationship was reversed after adjustments for body weight (g/(kg.d)). The inverse association of plant protein intakes was stronger with BMI z-score and body fat percentage (BF%) compared to animal protein intakes. Additionally, BMI and BF% were positively associated with energy percentage of animal protein. Conclusions: This sample of European adolescents appeared to have adequate total protein intake. Our findings suggest that plant protein intakes may play a role in preventing obesity among European adolescents. Further longitudinal studies are needed to investigate the potential beneficial effects observed in this study in the prevention of obesity and related chronic diseases