Measuring Dislocation Density in Aluminum with Resonant Ultrasound Spectroscopy

Dislocations in a material will, when present in enough numbers, change the speed of propagation of elastic waves. Consequently, two material samples, differing only in dislocation density, will have different elastic constants, a quantity that can be measured using Resonant Ultrasound Spectroscopy. Measurements of this effect on aluminum samples are reported. They compare well with the predictions of the theory.Comment: 4 pages, 2 figure

Hybrid mesoporous electrodes evidence CISS effect on water oxidation

Controlling product selectivity is essential for improving the efficiency of multi-product reactions. Electrochemical water oxidation is a reaction of main importance in different applications, e.g., renewable energy schemes and environmental protection, where H2O2 and O2 are the two principal products. In this Communication, the product selectivity of electrochemical water oxidation was controlled by making use of the chiral induced spin selectivity (CISS) effect at mesoporous-TiO2 on the molecule-modified Au substrate. Our results show a decrease in H2O2 formation when using chiral hetero-helicene molecules adsorbed on the Au substrate. We propose a mechanism for this kinetic effect based on the onset of CISS-induced spin polarization on the Au-helicene chiral interface. We also present a new tunable substrate to investigate the CISS mechanism.Fil: Vensaus, Priscila. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liang, Yuehwei. Ecole Polytechnique Federale de Lausanne. Max Planck-epfl Center For Molecularnanosciencie And Technology; FranciaFil: Zigon, Nicolas. Ecole Polytechnique Federale de Lausanne; FranciaFil: Avarvari, Narcis. Ecole Polytechnique Federale de Lausanne; FranciaFil: Mujica, Vladimiro. Centre National de la Recherche Scientifique; FranciaFil: Soler Illia, Galo Juan de Avila Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martin. Instituto de Nanosistemas; ArgentinaFil: Lingenfelder, Magalí Alejandra. Ecole Polytechnique Federale de Lausanne. Max Planck-epfl Center For Molecularnanosciencie And Technology; Franci

A mouse model of high trait anxiety shows reduced heart rate variability that can be reversed by anxiolytic drug treatment

Increasing evidence suggests that specific physiological measures may serve as biomarkers for successful treatment to alleviate symptoms of pathological anxiety. Studies of autonomic function investigating parameters such as heart rate (HR), HR variability and blood pressure (BP) indicated that HR variability is consistently reduced in anxious patients, whereas HR and BP data show inconsistent results. Therefore, HR and HR variability were measured under various emotionally challenging conditions in a mouse model of high innate anxiety (high anxiety behaviour; HAB) vs. control normal anxiety-like behaviour (NAB) mice. Baseline HR, HR variability and activity did not differ between mouse lines. However, after cued Pavlovian fear conditioning, both elevated tachycardia and increased fear responses were observed in HAB mice compared to NAB mice upon re-exposure to the conditioning stimulus serving as the emotional stressor. When retention of conditioned fear was tested in the home cage, HAB mice again displayed higher fear responses than NAB mice, while the HR responses were similar. Conversely, in both experimental settings HAB mice consistently exhibited reduced HR variability. Repeated administration of the anxiolytic NK1 receptor antagonist L-822429 lowered the conditioned fear response and shifted HR dynamics in HAB mice to a more regular pattern, similar to that in NAB mice. Additional receiver-operating characteristic (ROC) analysis demonstrated the high specificity and sensitivity of HR variability to distinguish between normal and high anxiety trait. These findings indicate that assessment of autonomic response in addition to freezing might be a useful indicator of the efficacy of novel anxiolytic treatments

Negative emotions of Secondary school students in learning basketball in Physical Education

The study of emotions in Physical Education is becoming more frequent and is due to the affective turn that is being developed in the educational field.The objective of this research was to analyze the perception and attribution of students on negative emotions for subjective well-being during the practice of basketball in physical education, according to the type of motor task, gender and educational center.The research approach is qualitative, with an interpretative and phenomenological design. 20 female students and 24 male students from two educational centers in the city of Madrid participated. For data collection, semi-structured interviews and personal diaries were used. The data obtained were subjected to a deductive-inductive content analysis with the Atlas.ti 7.5 computer program. The results show 18 codes or emotional attributions, which include meanings about negative emotions such as anger, shame, boredom, anguish, nervousness, fear, insecurity, sadness and frustration. According to the type of motor task and gender, codes on sports competition stood out. Depending on the educational center, they highlighted codes around the sports experience. It is concluded that, to promote the subjective well-being of students in basketball practices in physical education, it could be appropriate to evaluate emotions, apply adaptive teaching and innovate with alternative models of sports teaching