Teaching and the ethics of literature

The piece approaches the problem of the political content of books by way of an analogy. It suggests that we see books as teachers. We should consider them as similar to the human beings who have taught us the most in life. Those teachers will offer many good things, but given that fine teachers are almost always strong and idiosyncratic personalities, they will offer us some lessons that are less than edifying. We shouldn’t throw them out for that. We should sift their lessons and learn from their best. As the Band sings it: You take what you need and you leave the rest

Lunar Environment Simulation for a High Performance Motor

NASA and the Canadian Space Agency (CSA) through a CSA contractor, Argo Space/Robotics Division, partnered to perform environmental performance tests on a high torque producing motor. CSA provided the motor and NASA provided a thermal vacuum chamber capable of achieving high vacuum (P < 1 E-5 torr) and temperatures between 25 and 400 K. NASA also provided a dynamometer system capable of measuring and or applying break torque between 0 and 28 Nm. The two primary goals of the test were to simulate sun exposed and shadow condition expected on the lunar surface in order to determine survivability of the motor at extreme temperature conditions and to operate the motor under a constant break load of 6.8 Nm in the temperature range of 30K to 415K. A secondary objective of the test was to operate the motor for 15 km under 6.8 Nm of load. The primary goals of the test were fully achieved. The secondary goal was partially achieved

Effects of different footwear on kinetics, kinematics and muscle forces during the barbell back squat; an exploration using Bayesian modelling

The current study aimed to explore the effects of different footwear on kinetics, kinematics and muscle forces during the barbell back squat in both male and female lifters using Bayesian modelling. Twelve male and twelve female lifters completed squats at 70% of their 1 repetition maximum, in four different footwear conditions (Adidas weightlifting shoe, Inov-8 weightlifting shoe, Cross-fit and minimal footwear). Three-dimensional kinematics were measured using an eight-camera motion analysis system, ground reaction forces using a force platform and muscle/ joint forces using musculoskeletal modelling techniques. Differences between footwear were examined using Bayesian 4 (FOOTWEAR) * 2 (GENDER) mixed ANOVA’s. Peak quadriceps force was greater in the Adidas (male=89.78/female=70.56N/kg), Cross-fit (male=92.41/female=70.82N/kg) and Inov-8 (male=91.57/female=68.21N/kg) conditions compared to minimal footwear (male=82.61/female=64.40N/kg). In addition, peak patellofemoral stress and patellar tendon forces were greater in the Adidas (patellar tendon force: male=64.67/female=42.89N/kg & patellofemoral stress: male=143.21/female=118.92KPa/kg), Cross-fit (patellar tendon force: male=67.89/female=43.52N/kg & patellofemoral stress: male=146.02/female=114.73KPa/kg) and Inov-8 (patellar tendon force: male=64.08/female=41.04N/kg & patellofemoral stress: male=193.09/female=169.09KPa/kg) conditions compared to minimal footwear (patellar tendon force: male=56.75/female=39.92N/kg & patellofemoral stress: male=134.06/female=108.91KPa/kg). Finally, angular ROM was greater in the minimal footwear (male=28.04/female=33.75°) compared to the Adidas (male=26.85/female=30.73°) and Inov-8 (male=26.92/female=32.63°) conditions. The findings from the current investigation therefore indicate that weightlifting footwear may be able to enhance lower extremity muscle development and improve squat biomechanics owing to a reduced trunk angular ROM; however, this is likely to be at the expense of increased knee joint loading

Acute effects of knee wraps/ sleeve on kinetics, kinematics and muscle forces during the barbell back squat

PURPOSE: The aim of the current investigation was to comparatively examine the effects of knee wraps/ sleeves on kinetics, three-dimensional kinematics and muscle forces during the barbell back squat. METHODS: Fifteen male lifters completed squats at 70% of their 1 repetition maximum, in four different conditions (nothing, competition knee wrap, training knee wrap and knee sleeve). Three-dimensional kinematics were measured using an eight-camera motion analysis system, ground reaction forces (GRF) using a force platform and muscle forces using musculoskeletal modelling techniques. Differences between conditions were examined using one-way repeated measures ANOVA. RESULTS: The results showed that the integral of the quadriceps (nothing=58.30, competition=51.87 & training wrap=53.33N/kg·s), hamstring (nothing=39.01, competition=35.61 & training wrap=33.97N/kg·s), gluteus maximus (nothing=24.29, competition=22.22 & training wrap=21.03N/kg·s), gastrocnemius (nothing=7.25, competition=5.97 & training wrap=6.39N/kg·s) and soleus muscles (nothing=15.49, competition=12.75 & training wrap=13.64N/kg·s) during the ascent phase was significantly greater in the nothing condition compared to both knee wraps. In addition, whilst knee wraps and knee sleeves significantly improved perceived knee stability, perceived comfort was significantly reduced in the knee wraps and improved in the knee sleeve. CONCLUSIONS: Taking into account the reduced muscle kinetics, knee wraps may diminish lower extremity muscle development. Therefore, knee sleeves may be more efficacious for athletes who regularly utilize the back squat for their training goals, although further longitudinal analyses are required before this can be fully established

Two-experiment examination of habitual and manipulated foot placement angles on the kinetics, kinematics, and muscle forces of the barbell back squat in male lifters.

This two-experiment study aimed to examine the effects of different habitual foot placement an-gles and also the effects of manipulating the foot placement angle on the kinetics, three-dimensional kinematics and muscle forces of the squat. In experiment 1 seventy lifters completed squats at 70% of their 1 repetition maximum using a self-preferred placement angle and they were separated based on their habitual foot angle, into three groups HIGH, MEDIUM and LOW. In experiment 2, twenty lifters performed squats using the same relative mass in 4 different foot placement angle conditions (0°, 21°, 42°and control). Three-dimensional kinematics were measured using an eight-camera motion analysis system, ground reaction forces (GRF) using a force platform and muscle forces using musculoskeletal modelling techniques. In ex-periment 1 the impulse of the medial GRF in the descent and ascent phases was significantly greater in the HIGH group compared to LOW and in experiment 2 statistically greater in the 42° compared to the 21°, 0° and control conditions. Experiment 2 showed that the control condition statistically increased quadriceps muscle forces in relation to 0°, whereas the 0° condition significantly enhanced gluteus maximus, gastrocnemius and soleus forces compared to control. In experiment 1 patellofemoral joint stress was significantly greater in the HIGH group compared to LOW and in experiment 2 patellar and patellofemoral loading were statistically greater in the control compared to the 42°, 21°, 0° and control conditions. Owing to the greater medial GRF’s, increased foot placement angles may improve physical preparedness for sprint performance and rapid changes of direction. Reducing the foot angle may attenuate the biomechanical mechanisms linked to the aetiology of knee pathologies and to promote gluteus maximus, gastrocnemius and soleus muscular development. As such, though there does not appear to be an optimal foot placement angle, the observations from this study can be utilized by both strength and conditioning and sports therapy practitioners seeking to maximize training and rehabilitative adaptations

The Reinforcing Therapist Performance (RTP) experiment: Study protocol for a cluster randomized trial

<p>Abstract</p> <p>Background</p> <p>Rewarding provider performance has been recommended by the Institute of Medicine as an approach to improve the quality of treatment, yet little empirical research currently exists that has examined the effectiveness and cost-effectiveness of such approaches. The aim of this study is to test the effectiveness and cost-effectiveness of providing monetary incentives directly to therapists as a method to improve substance abuse treatment service delivery and subsequent client treatment outcomes.</p> <p>Design</p> <p>Using a cluster randomized design, substance abuse treatment therapists from across 29 sites were assigned by site to either an implementation as usual (IAU) or pay-for-performance (P4P) condition.</p> <p>Participants</p> <p>Substance abuse treatment therapists participating in a large dissemination and implementation initiative funded by the Center for Substance Abuse Treatment.</p> <p>Intervention</p> <p>Therapists in both conditions received comprehensive training and ongoing monitoring, coaching, and feedback. However, those in the P4P condition also were given the opportunity to earn monetary incentives for achieving two sets of measurable behaviors related to quality implementation of the treatment.</p> <p>Outcomes</p> <p>Effectiveness outcomes will focus on the impact of the monetary incentives to increase the proportion of adolescents who receive a targeted threshold level of treatment, months that therapists demonstrate monthly competency, and adolescents who are in recovery following treatment. Similarly, cost-effectiveness outcomes will focus on cost per adolescent receiving targeted threshold level of treatment, cost per month of demonstrated competence, and cost per adolescent in recovery.</p> <p>Trial Registration</p> <p>Trial Registration Number: NCT01016704</p

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

Functional principal component analysis reveals maturation-related differences in the countermovement jump force-time waveform

Purpose: Recent studies have applied temporal phase analysis to compare the characteristics of the countermovement jump (CMJ) force-time data between groups of athletes. Whilst these studies have provided valuable contributions to our understanding of (for example) sex, maturation and sport-specific differences in neuromuscular function, they have been limited by the fact that pre-selection of discreet data points is dependent on knowledge of the movement which may lead to abandoning potentially relevant data, and that these discreet data points do not explicitly account for the multidimensional nature of time series data. Functional principal component analysis (fPCA) can be applied to temporal waveforms without a-priori selection of important features, and has been proposed as a useful method to gain greater insight into human motion data. The aims of this study were therefore to investigate the variance in CMJ waveform data between academy soccer players, and to compare the first few principal components (PC) between maturation groups. Methods: Ninety-nine football players aged 9 - 18 from a Cat. 2 soccer academy in the UK volunteered to take part. Players were categorised as pre, circa or post peak height velocity according to maturational offset prediction equations. Following a RAMP warm up, participants performed three CMJ’s with their hands on their hips, with 1-min recovery between jumps. All jumps were performed on a portable force plate sampled at 1000hz. Participants were instructed to jump as high as they could, and countermovement depth was self-selected. The time series of data were normalised to body mass on the magnitude axis, and to 0-100% of the movement cycle of the time axis. All data was used as input for the variance matrices and the mean waveform of the three jumps represented a row in the matrix. fPCA resulted in PC scores and time-series loading vectors for each PC. A one-way ANOVA was conducted to investigate between group differences in loading scores, and significant main effects were followed with Bonferoni adjusted (98.3%) confidence intervals. Linear regression was performed to investigate relationships between jump height and PC scores. Results: The first five PC explained more than 90% of the variance in force parameters and were characterised by phase shift, (PC1 and PC4), waveform (PC2 and PC%) and magnitude (PC3) features. A one-way ANOVA revealed a significant between-group main effects for PC1 (F2,96 = 3.85, p = 0.02) and PC3 (F2,96 = 9.62, p < 0.001). Specifically, PC1 loadings for CIRCA were between 0.5 – 15.5 units lower than pre PHV players, and PC3 loadings for pre were between 1.5 – 9.8 and 2.8 – 12.7 lower than circa and post, respectively. Linear regression showed that PC3 (r=0.77, p< 0.001), PC4 (r=0.28, p=< 0.01) and PC5 (r=0.38, p=< 0.001) were significantly related to jump height. Conclusions: Around PHV, soccer players begin to adopt a CMJ technique which is characterized by a longer period of unweighting and shorter propulsion-acceleration, and both circa and post PHV players generate greater relative peak force between 85-90% of the movement cycle, compared with pre-PHV Practical Applications: These data provide greater insight into differences in jump technique and variables affecting jump performance in youth soccer players at different stages of maturation, and could be used to inform age-specific training interventions