Appearance of room temperature ferromagnetism in Cu-doped TiO2−δ_{2-\delta} films

In recent years there has been an intense search for room temperature ferromagnetism in doped dilute semiconductors, which have many potentially applications in spintronics and optoelectronics. We report here the unexpected observation of significant room temperature ferromagnetism in a semiconductor doped with nonmagnetic impurities, Cu-doped TiO$_2$ thin films grown by Pulsed Laser Deposition. The magnetic moment, calculated from the magnetization curves, resulted surprisingly large, about 1.5 $\mu_B$ per Cu atom. A large magnetic moment was also obtained from ab initio calculations using the supercell method for TiO$_2$ with Cu impurities, but only if an oxygen vacancy in the nearest-neighbour shell of Cu was present. This result suggests that the role of oxygen vacancies is crucial for the appearance of ferromagnetism. The calculations also predict that Cu doping favours the formation of oxygen vacancies.Comment: 4 pages, 3 figures, published in Phys. Rev. B (Rapid Comm.

Effects of a High Intensity Interval Training (HIIT) in lactate and heart rate during the menstrual cycle in young skater athletes

INTRODUCTION: High intensity interval training (HIIT) effects on heart rate and lactate concentration have been widely documented in male and female athletes. However, there few reports focused to study the dynamics of these cardiac and metabolic markers during the different phases of the menstrual cycle. PURPOSE: The aim of this studywas analyze the dynamics of heart rate and lactate concentration during a HIIT protocol in the different phases of the menstrual cycle (MC) in young eumenorrheic athletes women. METHODS: Two young skater athletes (14.5±0.7 yrs.) with regular menstrual cycles were recruited. The normality of the cycle was measured with a menstrual calendar. The estimated VO2 max was assessed in an electrically braked cycle ergometer (Lode) using a graded exercise test. The HIIT protocol consisted of 12 sessions of 6 high intensity intervals at 80% VO2 max, and 6 rest intervals at 40% VO2 max. Basal and post-exercice heart rate (HR) and lactate concentrations (LC) were measured with a pulsometer (polar FT1) or test strips (Nova Biomedical), respectively. The MC was divided in six phases: Early follicular (EF), Mid follicular (MF), Late follicular (LF), Early luteal (EL), Mid luteal (ML) and Late luteal (LL), using the date since their first menstrual discharge as the start of the EF phase. RESULTS: There was a significative correlation between HR and LC (r: 0.37, p: 0.0034) throughout the 12 HIIT sessions, but this was not statistically significant in EF (r: 0.36, p: 0.21), MF (r: 0.86, p: 0.12), LF (r: 0.14, p: 0.68), ML (r: 0.04, p: 0.92) and LL (r: 0.67, p: 0.06). Interestingly, we did observe a highly significant correlation between HR and LC (r = 0.68, p = 0.0033) in the EL phase, characterized by rising progesterone levels and a transient decrease of estradiol concentrations. CONCLUSION: These preliminary results suggest that the normal fluctuation of steroid hormone levels during the menstrual cycle can affect the dynamics of HR and LC in eumenorrheic athletes

The Second Generalized Hamming Weight of Some Evaluation Codes Arising from Complete Bipartite Graphs

Abstract In this paper we compute the second generalized Hamming weight of the evaluation codes associated to complete bipartite graphs. The main result depends on the minimum distance and second generalized Hamming weight of the generalized Reed-Solomon codes. Mathematics Subject Classification: 94B27, 94B6

The relationship between aerobic fitness and depression level determined with Hamilton scale in older adults

INTRODUCTION: Depression is a major public health problem associated with both morbidity and mortality throughout the world, in Mexico epidemiological reports show a prevalence of depression in older adults of 9.5% in women and 5% in men; it is widely held that regular exercise and physical activity in older subjects have a significant impact on psychological health and well-being. PURPOSE: To determine whether if higher aerobic fitness is associated with decreased symptoms of clinical depression in older adults. METHODS: Participants (n=21) included individuals raging ages from 61 to 72 years old and were not regular exercisers. The 6 minute walking test was used to determine the aerobic fitness, the total distance covered during the test was determined with pedometers; all subjects were free of unstable cardiovascular symptoms and disabilities that could interfere with performance in the sub-maximal exercise test. Indirect Peak Oxygen Consumption (VO2peak) was obtained with the equation stablished by Burr et al. (2011). Depression Symptoms were evaluated using the Hamilton Depression Scale which consisted of an interview of the subjects and scoring 17 items defined in terms of a series of categories of increasing intensity. Statistical analyses included a non-parametric Spearman correlation test to determine the association between predicted VO2peak and depression, level of significance was stablished at P≤0.05. RESULTS: Twenty one overweight (BMI 29.3±3.7 kg/m2) subjects that presented mild clinical depression symptoms were included in the study. A moderate negative correlation between predicted peak VO2 and depression was obtained, with a coefficient of r= -0.5099 (P≤0.05). A regression analysis was performed to establish the significant predictor of VO2 entering the analysis a psychological variable as a dependent factor (P value 0.0102). CONCLUSION: Based on the results, there is evidence that aerobic exercise could be a plausible and healthy strategy to avert depressive symptoms in the appearance of clinical depression in older adults

Pre-sleep protein supplementation after an acute bout of evening resistance exercise does not improve next day performance or recovery in resistance trained men

BACKGROUND: To evaluate the effect of pre-sleep protein supplementation after an acute bout of evening resistance training on next day performance and recovery the following day in physically active men. METHODS: Eighteen resistance trained men performed a single bout of resistance exercise then received either a pre-sleep protein (PRO) supplement containing 40 g of casein protein (PRO; n = 10; mean ± SD; age = 24 ± 4 yrs; height = 1.81 ± 0.08 m; weight = 84.9 ± 9.5 kg) or a non-caloric, flavor matched placebo (PLA; n = 8; age = 28 ± 10 yrs; height = 1.81 ± 0.07 m; weight = 86.7 ± 11.0 kg) 30 min before sleep (1 h after a standard recovery drink). Blood samples were obtained pre-exercise and the following morning (+12-h) to measure creatine kinase and C-reactive protein. Visual analog scales were utilized to assess perceived pain, hunger, and recovery. One-repetition maximum (1RM) tests for barbell bench press and squat were performed pre-exercise and the following morning (+12-h). Statistical analysis was performed using SPSS (V.23) and p ≤ 0.05 was considered statistically significant. RESULTS: There were no significant differences between the groups in next morning performance or muscle damage biomarkers. However, pre-sleep PRO resulted in a lower perception of hunger that approached significance the following morning when compared to PLA (PRO:43.6 ± 31.2, PLA: 69.4 ± 2.22; 95% C.I. = −53.6, 2.0; p = 0.07; d = 0.95). CONCLUSIONS: Following an evening bout of exercise, pre-sleep PRO did not further improve next morning muscle damage biomarkers or maximal strength performance in resistance trained men compared to a non-caloric PLA. However, there may be implications for lower perceived hunger the next morning with pre-sleep PRO consumption compared to PLA

Saliva secretory IgA kinetics in obese subjects submitted to a graded exercise test

INTRODUCTION: Secretory IgA (sIgA) is predominant immunoglobulin in secretions of the mucosal immune system. It inhibit attachment and replication of pathogenic microorganism, preventing colonization by these pathogens. Therefore, sIgA is consider the first line of defense against pathogens. Previous studies have indicated a direct link between low salivary sIgA levels with of upper respiratory tract infections (UTRI) episodes in endurance sports and elite athletes. PURPOSE: Determine the effect of a maximal graded exercise test on the saliva sIgA levels in obese adult subjects. METHODS: Eleven obese male subjects (Age 31± 1.53 years) were recruited. The Body Mass Index (BMI) and, Waist Circumference (WC) were measured. Graded exercise test was performed on an electrically-braked cycle ergometer (Lode). The Heart rate (HR) was registered using a digital pulse meter (Polar FT1 model) before, immediately finished the exercise and after 30 min post- exercise test. The saliva samples were collected alongside with HR during the test. RESULTS: The WC (110.37 ± 3.89 cm) and BMI (34.73 ± 1.62 kg/m2) values confirmed the obesity state in the participants. The HR at basal was 77.09 ± 3.10 bpm, at post exercise, the HR mean was 175.45 ± 4.94 bpm (p \u3c0.0001 vs basal). Finally, at 30 post exe, the HR was 91.81 ± 3.01 bpm (P \u3c0.0001 vs post-exe). In basal state, the sIgA concentration was 94.21 ± 13.57 µm/mL. At post exe, the sIgA mean was 175.9 ± 22.45 µm/mL (p\u3c0.05 vs basal). Finally, 30’ post-exercise the sIgA level was 91.39 ± 10.40 µm/mL. However, the sIgA was not modified by the exercise. CONCLUSION: The present work demonstrates that the salivary sIgA increases temporally as a response to the graded exercise test in obese adults. Although, the changes in the sIgA concentration was not accompanied with a major sIgA secretion in the saliva