4,693 research outputs found
A Comparison of Training With a Velocity Loss Threshold or to Repetition Failure on Upper-Body Strength Development in Professional Australian Footballers.
PURPOSE: To compare resistance training using a velocity loss threshold with training to repetition failure on upper-body strength parameters in professional Australian footballers. METHODS: A total of 26 professional Australian footballers (23.9 [4.2] y, 189.9 [7.8] cm, 88.2 [8.8] kg) tested 1-repetition-maximum strength (FPmax) and mean barbell velocity at 85% of 1-repetition maximum on floor press (FPvel). They were then assigned to 2 training groups: 20% velocity loss threshold training (VL; n = 12, maximum-effort lift velocity) or training to repetition failure (TF; n = 14, self-selected lift velocity). Subjects trained twice per week for 3 weeks before being reassessed on FPmax and FPvel. Training volume (total repetitions) was recorded for all training sessions. No differences were present between groups on any pretraining measure. RESULTS: The TF group significantly improved FPmax (105.2-110.9 kg, +5.4%), while the VL group did not (107.5-109.2 kg, +1.6%) (P > .05). Both groups significantly increased FPvel (0.38-0.46 m·s-1, +19.1% and 0.37-0.42 m·s-1, +16.7%, respectively) with no between-groups differences evident (P > .05). The TF group performed significantly more training volume (12.2 vs 6.8 repetitions per session, P > .05). CONCLUSIONS: Training to repetition failure improved FPmax, while training using a velocity loss threshold of 20% did not. Both groups demonstrated similar improvements in FPvel despite the VL group completing 45% less total training volume than the TF group. The reduction in training volume associated with implementing a 20% velocity loss threshold may negatively impact the development of upper-body maximum strength while still enhancing submaximal movement velocity
Birth after caesarean section: Changes over a nine-year period in one Australian state
Objectives: to describe the outcomes related to birth after a caesarean section (CS) in one Australian state, New South Wales (NSW), over a nine-year period. The objectives were to determine whether changes had occurred in the rates of attempted and successful vaginal birth after caesarean section (VBAC), induction of labour, place of birth, admission to special care or neonatal intensive care nursery and perinatal mortality. Design and setting: cross-sectional analytic study of hospital births in New South Wales using population-based data from 1998-2006. Participants: women experiencing the next birth after a CS where: the total number of previous CS was 1; the presentation at birth was vertex; it was a singleton pregnancy; and, the estimated gestational age was greater than or equal to 37 weeks. A total of 53,455 women met these criteria. Measurements: data were obtained from NSW Health Department's Midwives Data Collection (MDC). The MDC includes all live births and stillbirths of at least 20 weeks gestation or 400. g birth weight in the state. Findings: over the nine-year period, the rate of vaginal birth after caesarean section declined significantly (31-19%). The proportion of women who 'attempted a vaginal birth' also declined (49-35%). Of those women who laboured, the vaginal birth rate declined from 64% to 53%. Babies whose mothers 'attempted' a VBAC were significantly less likely to require admission to a special care nursery (SCN) or neonatal intensive care (NICU). The perinatal mortality rate in babies whose mothers 'attempted' a VBAC was higher than those babies born after an elective caesarean section although the absolute numbers are very small. Key conclusions: rates of VBAC have declined over this nine-year period. Rates of neonatal mortality and proxy measures of morbidity (admission to a nursery) are generally in the low range for similar settings. Implications for practice: decisions around the next birth after CS are complex. Efforts to keep the first birth normal and support women who have had a CS to have a normal birth need to be made. More research to predict which women are likely to achieve a successful VBAC and the most effective ways to facilitate a VBAC is essential. Midwives have a critical role to play in these endeavours. © 2009 Elsevier Ltd
An unusual case of pancreatic fistula.
We report an unusual case of a pancreatic fistula communicating with an appendicectomy wound. This occurred following an episode of acute haemorrhagic pancreatitis. The patient was initially admitted with signs and symptoms indicating appendicitis and went to theatre for an open appendicectomy. However, this did not resolve his symptoms and a laparotomy was performed the next day revealing haemorrhagic pancreatitis. He endured a stormy post-operative course, the cause of which was found to be an external pancreatic fistula with discharge of amylase-rich fluid from the Lanz incision. A trial of conservative management failed despite multiple percutaneous drainage procedures and treatment with broad-spectrum antibiotics. After a second opinion was sought, it was decided to fit a roux loop anastomosis between the head of the pancreas and the duodenum to divert the fistulous fluid. This procedure was a success and the patient remains well 2 years later
Validity and interunit reliability of 10 Hz and 15 Hz GPS units for assessing athlete movement demands
The purpose of this study was to assess the validity and interunit reliability of 10 Hz (Catapult) and 15 Hz (GPSports) Global Positioning System (GPS) units and investigate the differences between these units as measures of team sport athlete movement demands. A team sport simulation circuit was completed by 8 trained male participants. The movement demands examined included: total distance covered (TD), average peak speed, and the distance covered, time spent, and the number of efforts performed low-speed running (0.00-13.99 km·h-1), high-speed running (14.00-19.99 km·h-1), and very highspeed running (>20.00 km·h-1). The degree of difference between the 10 Hz and the 15 Hz GPS units and validity was assessed using a paired samples t-test. Pearson's correlations were also used for validity assessment. Interunit reliability was established using percentage typical error of measurement (%TEM) and intraclass correlations. The findings revealed that 10 Hz GPS units were a valid (p > 0.05) and reliable (%TEM = 1.3%) measure of TD. In contrast, the 15 Hz GPS units exhibited lower validity for TD and average peak speed. Further, as the speed of movement increased the level of error for the 10 Hz and 15 Hz GPS units increased (% TEM = 0.8-19.9). The findings from this study suggest that comparisons should not be undertaken between 10 Hz and 15 Hz GPS units. In general, the 10 Hz GPS units measured movement demands with greater validity and interunit reliability than the 15 Hz units, however, both 10 Hz and 15 Hz units provided the improved measures of movement demands in comparison to 1 Hz and 5 Hz GPS units. © 2014 National Strength and Conditioning Association
Non-clinical interventions that increase the uptake and success of vaginal birth after caesarean section: A systematic review
Aim. The aim of this study was to review non-clinical interventions that increase the uptake and/or the success rates of vaginal birth after caesarean section. Background. Increases in rates of caesarean section are largely due to repeat caesarean section in a subsequent pregnancy. Concerns about vaginal birth after caesarean section have centred on the risk of uterine rupture. Nonetheless, efforts to increase the vaginal birth rate in these women have been made. This study reviews these in relation to non-clinical interventions. Data sources. Literature was searched up until December 2008 from five databases and a number of relevant professional websites. Review methods. A systematic review of quantitative studies that evaluated a non-clinical intervention for increasing the uptake and/or the success of vaginal birth after caesarean section was undertaken. Only study designs that involved a comparison group were included. Further exclusions were imposed for quality using the Critical Skills Appraisal Programme. Results. National guidelines influence vaginal birth after caesarean section rates, but a greater effect is seen when institutions develop local guidelines, adopt a conservative approach to caesarean section, use opinion leaders, give individualized information to women, and give feedback to obstetricians about mode of birth rates. Individual clinician characteristics may impact on the number of women choosing and succeeding in vaginal birth after caesarean section. There is inconsistent evidence that having private health insurance may be a barrier to the uptake and success of vaginal birth after caesarean section. Conclusion. Non-clinical factors can have a significant impact on vaginal birth after caesarean section uptake and success. © 2011 The Authors. Journal of Advanced Nursing © 2011 Blackwell Publishing Ltd
Clinical interventions that increase the uptake and success of vaginal birth after caesarean section: A systematic review
Aim. The aim of this study was to review clinical interventions that increase the uptake and/or the success rates of vaginal birth after caesarean section. Background. Repeat caesarean section is the main reason for the increase in surgical births. The risk of uterine rupture in women who have prior caesarean sections prevents many clinicians from recommending vaginal birth after caesarean. Despite this, support for vaginal birth after caesarean continues. Data sources. A search of five databases and a number of relevant professional websites was undertaken up to December 2008. Review methods. A systematic review of quantitative studies that involved a comparison group and examined a clinical intervention for increasing the uptake and/or the success of vaginal birth after caesarean section was undertaken. An assessment of quality was made using the Critical Skills Appraisal Programme. Results. Induction of labour using artificial rupture of membranes, prostaglandins, oxytocin infusion or a combination, was associated with lower vaginal birth rates. Cervical ripening agents such as prostaglandins and transcervical catheters may result in lower vaginal birth rates compared with spontaneous labour. The impact of epidural anaesthesia in labour on vaginal birth after caesarean success is inconclusive. X-ray pelvimetry is associated with reduced uptake of vaginal birth after caesarean and higher caesarean section rates. Scoring systems to predict likelihood of vaginal birth are largely unhelpful. There is insufficient data in relation to vaginal birth after caesarean section between different closure methods for the primary caesarean section. Conclusion. Clinical factors can affect vaginal birth after caesarean uptake and success. © 2011 The Authors. Journal of Advanced Nursing © 2011 Blackwell Publishing Ltd
Optical response of grain boundaries in upgraded metallurgical-grade silicon for photovoltaics
Using upgraded metallurgical-grade silicon (UMG-Si) is a cost-effective and energy-efficient approach for the production of solar cells. Grain boundaries (GBs) play a major role in determining the device performance of multicrystalline Si (mc-Si) solar cells. In this study two UMG-Si wafers, one from the middle part of a brick and the other from the top part of the same brick, were investigated. An excellent correlation was found between the grain misorientation and the corresponding optical response of GBs as indicated by photoluminescence (PL) imaging, electron backscattered diffraction (EBSD), and cross-sectional transmission electron microscopy (TEM). In addition, the PL features at random GBs depend also on the impurity levels in the wafer. In particular the PL emission was greatly enhanced in the narrow regions close to the random GB in the top wafer, which is an interesting phenomenon that may have potential application in high efficiency light-emission diodes (LEDs) based on Si. © 2011 Elsevier B.V.postprin
Translating concerns into action: a detailed qualitative evaluation of an interdisciplinary intervention on medical wards
Objectives To understand how frontline reports of day-to-day care failings might be better translated into improvement. Design Qualitative evaluation of an interdisciplinary team intervention to capitalise on the frontline experience of care delivery. Prospective clinical team surveillance (PCTS) involved structured interdisciplinary briefings to capture challenges in care delivery, facilitated organisational escalation of the issues they identified, and feedback. Eighteen months of ethnography and two focus groups were conducted with staff taking part in a trial of PCTS. Results PCTS fostered psychological safety – a confidence that the team would not embarrass or punish those who speak up. This was complemented by a hard edge of accountability, whereby team members would regulate their own behaviour in anticipation of future briefings. Frontline concerns were triaged to managers, or resolved autonomously by ward teams, reversing what had been well-established normalisations of deviance. Junior clinicians found a degree of catharsis in airing their concerns, and their teams became more proactive in addressing improvement opportunities. PCTS generated tangible organisational changes, and enabled managers to make a convincing case for investment. However, briefings were constrained by the need to preserve professional credibility, and the relative comfort afforded by the avoidance of accountability. At higher organisational levels, frontline concerns were subject to competition with other priorities, and their resolution was limited by the scale of the challenges they described. Conclusions Prospective safety strategies relying on staff-volunteered data do approximate the realities of frontline care, but still produce acceptable, negotiated accounts, subject to the many interdisciplinary tensions that characterise ward work. Nonetheless, they give managers access to these accounts, and support frontline staff to make incremental changes in their daily work. These are goals for learning healthcare organisations
Wolbachia endosymbionts induce neutrophil extracellular trap formation in human onchocerciasis
The endosymbiotic bacteria, Wolbachia, induce neutrophilic responses to the human helminth pathogen Onchocerca volvulus. The formation of Neutrophil Extracellular Traps (NETs), has been implicated in anti-microbial defence, but has not been identified in human helminth infection. Here, we demonstrate NETs formation in human onchocerciasis. Extracellular NETs and neutrophils were visualised around O. volvulus in nodules excised from untreated patients but not in nodules from patients treated with the anti-Wolbachia drug, doxycycline. Whole Wolbachia or microspheres coated with a synthetic Wolbachia lipopeptide (WoLP) of the major nematode Wolbachia TLR2/6 ligand, peptidoglycan associated lipoprotein, induced NETosis in human neutrophils in vitro. TLR6 dependency of Wolbachia and WoLP NETosis was demonstrated using purified neutrophils from TLR6 deficient mice. Thus, we demonstrate for the first time that NETosis occurs during natural human helminth infection and demonstrate a mechanism of NETosis induction via Wolbachia endobacteria and direct ligation of Wolbachia lipoprotein by neutrophil TLR2/6
Implementation of Web-Based Respondent-Driven Sampling among Men who Have Sex with Men in Vietnam
Objective: Lack of representative data about hidden groups, like men who have
sex with men (MSM), hinders an evidence-based response to the HIV epidemics.
Respondent-driven sampling (RDS) was developed to overcome sampling challenges
in studies of populations like MSM for which sampling frames are absent.
Internet-based RDS (webRDS) can potentially circumvent limitations of the
original RDS method. We aimed to implement and evaluate webRDS among a hidden
population.
Methods and Design: This cross-sectional study took place 18 February to 12
April, 2011 among MSM in Vietnam. Inclusion criteria were men, aged 18 and
above, who had ever had sex with another man and were living in Vietnam.
Participants were invited by an MSM friend, logged in, and answered a survey.
Participants could recruit up to four MSM friends. We evaluated the system by
its success in generating sustained recruitment and the degree to which the
sample compositions stabilized with increasing sample size.
Results: Twenty starting participants generated 676 participants over 24
recruitment waves. Analyses did not show evidence of bias due to ineligible
participation. Estimated mean age was 22 year and 82% came from the two large
metropolitan areas. 32 out of 63 provinces were represented. The median number
of sexual partners during the last six months was two. The sample composition
stabilized well for 16 out of 17 variables.
Conclusion: Results indicate that webRDS could be implemented at a low cost
among Internet-using MSM in Vietnam. WebRDS may be a promising method for
sampling of Internet-using MSM and other hidden groups.
Key words: Respondent-driven sampling, Online sampling, Men who have sex with
men, Vietnam, Sexual risk behavio
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