12,037 research outputs found
Social work education, training and standards in the Asia-Pacific region
This article discusses the joint project between the International Association of Schools of Social Work (IASSW) and the International Federation of Social Workers (IFSW) to establish guidelines for the training and standard setting that elucidates what social work represents on a global level. While it is impossible to address all the issues that might be significant in such a large scope, attention is given to the challenges establishing global standards might encounter in a region as diverse as the Asia-Pacific
EXAMINATION OF THE DIVING BOARD VIBRATION MODE OF SOFTBALL BATS
The purpose of this study was to investigate the longitudinal oscillations of an aluminum softball bat during the swing and impact and to correlate the vibrations with characteristics of the swing. A highly skilled adult male baseball player hit 20 slow-pitched softballs and 35 balls placed on a tee with a high-performance aluminum softball bat (34 in, 28 oz) that was instrumented with strain gauges to measure strain along the long axis. Analysis of strain gauge records indicate that, in all cases, the bat bent back during the early part of the swing, peaked at approximately 45 ms prior to contact (PC), and was bending toward the ball at impact. The frequency of bat oscillations during the swing was 7.37+.87 Hz and 5.3+1.25 Hz for pitched and teed balls, respectively. For teed balls, strain magnitude was significantly related to swing time, bat velocity PC, and post-impact ball velocity
SOFTBALL BAT VIBRATIONS DURING 'THE SWING AND IMPACT: A PRELIMINARY ANALYSIS OF EMPIRICAL DATA
The purpose of this study was to investigate softball bat vibrations during the swing and impact and to correlate the vibrations with characteristics of hitters and the swing. Four recreation-league college males and four females aged 21-23 yrs hit 15-25 pitched softballs with a high-performance aluminium softball bat (34 in, 28 oz). Analysis of strain gauge and videotaped records of 112 trials indicate that: 1. The frequency of bat oscillations during the swing ranged from 4.1 to 7.5 Hz, significantly below the 13 Hz of the lowest vibration mode of the clamped boundary condition; and 2. All hitters consistently demonstrated the effective utilisation of the diving board mode of vibration in timing the impact and swing such that the bat was 'releasing' elastic energy at impact that was stored during the swing
Idealized Antenna Patterns for Use in Communication-satellite Interference Studies
Idealized antenna patterns for communication satellite interference studie
Expected-value bias in routine third-trimester growth scans.
OBJECTIVES: Operators performing fetal growth scans are usually aware of the gestational age of the pregnancy, which may lead to expected-value bias when performing biometric measurements. We aimed to evaluate the incidence of expected-value bias in routine fetal growth scans and assess its impact on standard biometric measurements. METHODS: We collected prospectively full-length video recordings of routine ultrasound growth scans coupled with operator eye tracking. Expected value was defined as the gestational age at the time of the scan, based on the estimated due date that was established at the dating scan. Expected-value bias was defined as occurring when the operator looked at the measurement box on the screen during the process of caliper adjustment before saving a measurement. We studied the three standard biometric planes on which measurements of head circumference (HC), abdominal circumference (AC) and femur length (FL) are obtained. We evaluated the incidence of expected-value bias and quantified the impact of biased measurements. RESULTS: We analyzed 272 third-trimester growth scans, performed by 16 operators, during which a total of 1409 measurements (354 HC, 703 AC and 352 FL; including repeat measurements) were obtained. Expected-value bias occurred in 91.4% of the saved standard biometric plane measurements (85.0% for HC, 92.9% for AC and 94.9% for FL). The operators were more likely to adjust the measurements towards the expected value than away from it (47.7% vs 19.7% of measurements; P < 0.001). On average, measurements were corrected by 2.3 ± 5.6, 2.4 ± 10.4 and 3.2 ± 10.4 days of gestation towards the expected gestational age for the HC, AC, and FL measurements, respectively. Additionally, we noted a statistically significant reduction in measurement variance once the operator was biased (P = 0.026). Comparing the lowest and highest possible estimated fetal weight (using the smallest and largest biased HC, AC and FL measurements), we noted that the discordance, in percentage terms, was 10.1% ± 6.5%, and that in 17% (95% CI, 12-21%) of the scans, the fetus could be considered as small-for-gestational age or appropriate-for-gestational age if using the smallest or largest possible measurements, respectively. Similarly, in 13% (95% CI, 9-16%) of scans, the fetus could be considered as large-for-gestational age or appropriate-for-gestational age if using the largest or smallest possible measurements, respectively. CONCLUSIONS: During routine third-trimester growth scans, expected-value bias frequently occurs and significantly changes standard biometric measurements obtained. © 2019 the Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology
IL-12 and IL-4 activate a CD39-dependent intrinsic peripheral tolerance mechanism in CD8+ T cells
Immune responses to protein antigens involve CD4+ and CD8+ T cells, which follow distinct programs of differentiation. Naïve CD8 T cells rapidly develop cytotoxic T-cell (CTL) activity after T-cell receptor stimulation, and we have previously shown that this is accompanied by suppressive activity in the presence of specific cytokines, i.e. IL-12 and IL-4. Cytokine-induced CD8+ regulatory T (Treg) cells are one of several Treg-cell phenotypes and are Foxp3− IL-10+ with contact-dependent suppressive capacity. Here, we show they also express high level CD39, an ecto-nucleotidase that degrades extracellular ATP, and this contributes to their suppressive activity. CD39 expression was found to be upregulated on CD8+ T cells during peripheral tolerance induction in vivo, accompanied by release of IL-12 and IL-10. CD39 was also upregulated during respiratory tolerance induction to inhaled allergen and on tumor-infiltrating CD8+ T cells. Production of IL-10 and expression of CD39 by CD8+ T cells was independently regulated, being respectively blocked by extracellular ATP and enhanced by an A2A adenosine receptor agonist. Our results suggest that any CTL can develop suppressive activity when exposed to specific cytokines in the absence of alarmins. Thus negative feedback controls CTL expansion under regulation from both nucleotide and cytokine environment within tissues
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