Dynamic features of the selective pressure on the human immunodeficiency virus type 1 (HIV-1) gp120 CD4-binding site in a group of long term non progressor (LTNP) subjects.

Abstract The characteristics of intra-host human immunodeficiency virus type 1 (HIV-1) env evolution were evaluated in untreated HIV-1-infected subjects with different patterns of disease progression, including 2 normal progressor [NP], and 5 Long term non-progressor [LTNP] patients. High-resolution phylogenetic analysis of the C2-C5 env gene sequences of the replicating HIV-1 was performed in sequential samples collected over a 3–5 year period; overall, 301 HIV-1 genomic RNA sequences were amplified from plasma samples, cloned, sequenced and analyzed. Firstly, the evolutionary rate was calculated separately in the 3 codon positions. In all LTNPs, the 3rd codon mutation rate was equal or even lower than that observed at the 1st and 2nd positions (p = 0.016), thus suggesting strong ongoing positive selection. A Bayesian approach and a maximum-likelihood (ML) method were used to estimate the rate of virus evolution within each subject and to detect positively selected sites respectively. A great number of N-linked glycosylation sites under positive selection were identified in both NP and LTNP subjects. Viral sequences from 4 of the 5 LTNPs showed extensive positive selective pressure on the CD4-binding site (CD4bs). In addition, localized pressure in the area of the IgG-b12 epitope, a broad neutralizing human monoclonal antibody targeting the CD4bs, was documented in one LTNP subject, using a graphic colour grade 3-dimensional visualization. Overall, the data shown here documenting high selective pressure on the HIV-1 CD4bs of a group of LTNP subjects offers important insights for planning novel strategies for the immune control of HIV-1 infection.</p

Dynamic motor imagery mentally simulates uncommon real locomotion better than static motor imagery both in young adults and elderly

A new form of Motor Imagery (MI), called dynamic Motor Imagery (dMI) has recently been proposed. The dMI adds to conventional static Motor Imagery (sMI) the presence of simultaneous actual movements partially replicating those mentally represented. In a previous research conducted on young participants, dMI showed to be temporally closer than sMI in replicating the real performance for some specific locomotor conditions. In this study, we evaluated if there is any influence of the ageing on dMI. Thirty healthy participants were enrolled: 15 young adults (27.1\ub13.8 y.o.) and 15 older adults (65.9\ub19.6y.o.). The performance time and the number of steps needed to either walk to a target (placed at 10m from participants) or to imagine walking to it, were assessed. Parameters were measured for sMI, dMI and real locomotion (RL) in three different locomotor conditions: forward walking (FW), backward walking (BW), and lateral walking (LW). Temporal performances of sMI and dMI did not differ between RL in the FW, even if significantly different to each other (p = 0.0002). No significant differences were found for dMI with respect to RL for LW (p = 0.140) and BW (p = 0.438), while sMI was significantly lower than RL in LW (p&lt;0.001). The p-value of main effect of age on participants' temporal performances was p = 0.055. The interaction between age and other factors such as the type of locomotion (p = 0.358) or the motor condition (p = 0.614) or third level interaction (p = 0.349) were not statistically significant. Despite a slight slowdown in the performance of elderly compared to young participants, the temporal and spatial accuracy was better in dMI than sMI in both groups. Motor imagery processes may be strengthened by the feedback generated through dMI, and this effect appears to be unaffected by age

High intensity intermittent games-based activity and adolescents’ cognition: moderating effect of physical fitness

Background: An acute bout of exercise elicits a beneficial effect on subsequent cognitive function in adolescents. The effect of games-based activity, an ecologically valid and attractive exercise model for young people, remains unknown; as does the moderating effect of fitness on the acute exercise-cognition relationship. Therefore, the aim of the present study was to examine the effect of games-based activity on subsequent cognition in adolescents, and the moderating effect of fitness on this relationship. Methods: Following ethical approval, 39 adolescents (12.3 ± 0.7 year) completed an exercise and resting trial in a counterbalanced, randomised crossover design. During familiarisation, participants completed a multi-stage fitness test to predict VO2 peak. The exercise trial consisted of 60-min games-based activity (basketball), during which heart rate was 158 ± 11 beats∙min−1. A battery of cognitive function tests (Stroop test, Sternberg paradigm, trail making and d2 tests) were completed 30-min before, immediately following and 45-min following the basketball. Results: Response times on the complex level of the Stroop test were enhanced both immediately (p = 0.021) and 45-min (p = 0.035) post-exercise, and response times on the five item level of the Sternberg paradigm were enhanced immediately post-exercise (p = 0.023). There were no effects on the time taken to complete the trail making test or any outcome of the d2 test. In particular, response times were enhanced in the fitter adolescents 45-min post-exercise on both levels of the Stroop test (simple, p = 0.005; complex, p = 0.040) and on the three item level of the Sternberg paradigm immediately (p = 0.017) and 45-min (p = 0.008) post-exercise. Conclusions: Games-based activity enhanced executive function and working memory scanning speed in adolescents, an effect particularly evident in fitter adolescents, whilst the high intensity intermittent nature of games-based activity may be too demanding for less fit children

Exercise intensities during a ballet lesson in female adolescents with different technical ability

To investigate the exercise intensity during a typical grade five ballet lesson, thirty-nine dancers (13–16 yrs) were divided into three different technical proficiency groups: low level (n = 13), intermediate level (n = 14), and high level (n = 12). A progressively incremented treadmill test was administered to determine V˙ O2max, individual ventilatory threshold (IVT), and the individual anaerobic threshold (IAT). Oxygen uptake (V˙ O2), heart rate (HR) and blood lactate (La) were then evaluated during a grade five ballet lesson. Oxygen uptake at IVT, IAT and maximal oxygen uptake were greater (p < 0.05) in the high-level dancers indicating a higher level of fitness. HR and %V˙ O2max obtained during the various exercises of the ballet lesson were similar among groups. During the ballet lesson, low technical level dancers had moreV˙ O2 and La values above (p < 0.05) the IAT than the other groups. Correlation analysis revealed that the number of exercises performed above IAT was positively related to anthropometric characteristics (BMI, %FM; r = 0.36, p < 0.05; r = 0.46, p < 0.01), negatively related to fitness parameters (V˙ O2IVT, V˙ O2IAT, V˙ O2max; r between – 0.43 and – 0.69; p < 0.001) and to technical level (r = – 0.70; p < 0.001). The subjects classified as having low technical abilities had lower fitness levels and performed more exercises above IAT than the more skilled dancers

Effect of warm up on energy cost and energy sources of a ballet dance exercise

To evaluate the effect of warm up on energy cost and energy sources of a ballet dance exercise, 12 adolescent talented female dancers performed a ballet exercise (30 s of tours piques en dedans on pointe) without and following a warm up. Warm up consisted in a light running followed by a period of stretching and two ballet exercises. The overall energy requirement of dance exercise (VO2eq) was obtained by adding the amount of VO2 during exercise above resting (aerobic source or VO2ex) to the VO2 up to the fast component of recovery (anaerobic alactic source or VO2al) and to the energy equivalent of peak blood lactate accumulation (anaerobic lactic source or VO2la-) of recovery. VO2eq of exercise preceded by warm up amounted to 37 +/- 3 ml kg(-1). VO2al represented the higher fraction (50 +/- 6%) of VO2eq, the remaining fractions were: 39 +/- 5% for VO2ex and 11 +/- 3% for VO2la-. VO2eq of exercise without warm up amounted to 38 +/- 3 ml kg(-1). This value was made up of: 26 +/- 6% by VO2ex, 56 +/- 6% by VO2al and 18 +/- 3% by VO2la-. Between exercise conditions, significant differences were found in VO2ex (P O-2max indicates a very demanding exercise. The anaerobic alactic source was the most utilized. It can be concluded that, when dance exercise was preceded by warm up, the anaerobic sources contribution decreased whereas the aerobic energy source increased

Assessing basketball ability in players with mental retardation

Background: Although athletes with mental retardation (MR) have achieved an important role, literature concerning the evaluation tests in basketball is still poor. Objective: To assess basketball ability before and after a 4-month training performed before championship for athletes with MR and to correlate ability variations with MR levels. Methods: 15 trained basketball players with MR (11 men and 4 women; age range 21-43 years; MR: 3 mild, 8 moderate, 8 severe and 1 profound). Athletes were tested before (pre) and after (post) 4 month training preceding the championship. The tests assessed 4 levels of ability, each one characterised by 4 fundamental areas of this game: ball handling, reception, passing and shooting. Each area was divided into 5 specific components. Results: The team average score, based on the score of each athlete's 4 levels, improved by 6.6 points (41.6 (SD 11.9) vs 48.2 (14.7)). The comparison between pre and post scores in each level showed increases (p<0.01), especially in level II (14.4 (3.5) vs 16.5 (3.3)) and in level III (7.1 (5.7) vs 9.2 (6.6)). Within level II, ball handling (3.67 (1.2) vs 4.37 (0.5); p<0.05) and passing (3.20 (1.2) vs 3.97 (1.3); p<0.01) improved; in level III reception (3.21 (1.1) vs 3.73 (1.1); p = 0.01) and shooting (1.82 (1.1) vs 2.45 (1.3); p<0.05) increased. Conclusions: A 4 month training caused a general improvement, especially evident in levels II and III. Total score reached in level II was negatively correlated with MR level (r = -0.56; p<0.05), indicating that athletes with lower MR obtained higher scores

Does living setting influence training adaptations in young girls?

To assess whether rural or urban setting may influence young girls’ fitness and coordinative abilities training adaptations following dance training. Forty-four dancers aged 11–12 years (21 urban, 23 rural) attended a 6-month dance training while continuing to practice their habitual physical activities (PA). Dancers’ fitness and motor coordination abilities were assessed by pre- and post-intervention tests (anthropometric measures, 1-mile run/walk, sit and reach, standing long jump, hand grip and four field tests of kinaesthetic discrimination and response orientation). PA was assessed using a self-report recall measure. After the intervention period, rural dancers significantly improved in 1-mile run/walk, lower limb kinaesthetic discrimination and response orientation ability tests. Significant differences between two groups in upper limb response orientation ability test were found. Both groups showed a significant increase in body height and weight. Multiple regression analysis indicated that time in nonorganized PA predicted some fitness and coordinative changes (1-mile run/walk, lower limb response orientation and kinaesthetic discrimination ability tests) following the training period, although the percentage of variance it could explain was moderate. Our results showed that training adaptations of some fitness and coordinative performances could be influenced by setting characteristics that provided opportunities for different types of PA

Contributions of selected fundamental factors to basketball performance in adult players with mental retardation

The purpose of this study was to determine the contributions of selected fundamental factors to basketball performance in adult players with mental retardation (MR). Fourteen trained male players with MR (32.1 6 7.4 years) were recruited. The athletes' performances were assessed using adapted basketball tests that assessed 4 ability levels of increasing difficulty (from I to IV), each one characterized by the analysis of 4 fundamental areas: ball handling, reception, passing, and shooting. The fundamental factors included anthropometric measurements (height, weight, and body mass index), static balance, muscular strength and endurance, explosive leg power, cardiovascular endurance, and motor coordination. This study showed that greater explosive leg power and upper-body muscular strength and endurance had significant contributions to ball handling (85%, p < 0.01), and explosive leg power had significant positive contribution in reception (59%, p < 0.05) and shooting (64%, p = 0.01). The forearm muscular strength and upper-body muscular strength and endurance had significant contributions to passing (78%, p = 0.01). Moreover, the greater explosive leg power had significant contribution in level II (46%, p < 0.05), in level III (52%, p < 0.05), and in global score (60%, p < 0.05). In conclusion, the results showed the possibility to determine the contribution of selected fundamental factors to basketball performance. Therefore, the basketball coach could improve a selected fundamental factor to increase specific basketball ability. This should be addressed in a specific training to help players with MR to perform successfully in their competitions