3 research outputs found
Rock-weir fishway I: flow regimes and hydraulic characteristics
<p>In recent years, ecologically oriented river engineering practices such as nature-like fishways have become a common solution to mitigate or compensate for negative environmental impacts. This study investigated the flow regimes and hydraulics of rock-weir-type nature-like fishways for different structure geometries (weir configurations, pool spacing and boulder diameter) and channel characteristics (bed slope and flow rate). A criterion was proposed to predict three distinct flow regimes (weir, transitional and streaming) based on quantitative thresholds associated with three dimensionless parameters for discharge, pool spacing and pool water depth. For the depth–discharge relationship, a new equation to predict the weir flow based on water depth, weir length and bed slope of the fishway was introduced. Finally, a maximum velocity reduction factor as a function of discharge was proposed to predict maximum weir velocity in rock-weir fishways. These results must be compared with the swimming ability of the fish that the fishway is being designed for to assess passability.</p
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Lung volume reduction eligibility in patients with COPD completing pulmonary rehabilitation: results from the UK National Asthma and COPD Audit Programme
Objectives To establish what proportion of patients completing a UK pulmonary rehabilitation (PR) programme meet the 2018 National Institute for Health and Care Excellence (NICE) chronic obstructive pulmonary disease (COPD) guideline (NG115) criteria to have a respiratory review to establish whether referral to a lung volume reduction multidisciplinary team would be appropriate. This respiratory review would include evaluation of the presence of hyperinflation and the presence of emphysema on CT scan. The NICE criteria include measures of breathlessness and exercise capacity but these parameters are not completely defined.Design Observational study.Setting PR programmes across the UK in 2015 (210 centres) and 2017 (184 centres) entering data into the Royal College of Physicians’ National Asthma and COPD Audit Programme.Participants 8295 (55.7%) of 14 889 patients in programmes using incremental shuttle walk test (ISWT) or 6-minute walk test (6MWT) as an outcome measure completed PR, and 4856 (32.6%) had complete data recorded (6MWT/ISWT, baseline spirometry, Medical Research Council (MRC) dyspnoea score).Results Depending on the walking test safety threshold adopted for the ISWT (≥140 m or ≥ 80 m) and the MRC dyspnoea score threshold used (MRC score ≥3 or ≥4 at the end of PR), between 4.9% and 18.1% of PR completers met the NICE criteria for a lung volume reduction-focused respiratory review.Conclusions Lung volume reduction therapies are beneficial in appropriately selected patients with COPD, but few procedures are performed, and treatment pathways are unclear. These data help to inform the feasibility of the approach recommended by NICE and highlight the need for future systematic pathways to reduce inequalities in patients being considered for effective treatments.</div
DataSheet1_Genetic predisposition may not improve prediction of cardiac surgery-associated acute kidney injury.pdf
Background: The recent integration of genomic data with electronic health records has enabled large scale genomic studies on a variety of perioperative complications, yet genome-wide association studies on acute kidney injury have been limited in size or confounded by composite outcomes. Genome-wide association studies can be leveraged to create a polygenic risk score which can then be integrated with traditional clinical risk factors to better predict postoperative complications, like acute kidney injury.Methods: Using integrated genetic data from two academic biorepositories, we conduct a genome-wide association study on cardiac surgery-associated acute kidney injury. Next, we develop a polygenic risk score and test the predictive utility within regressions controlling for age, gender, principal components, preoperative serum creatinine, and a range of patient, clinical, and procedural risk factors. Finally, we estimate additive variant heritability using genetic mixed models.Results: Among 1,014 qualifying procedures at Vanderbilt University Medical Center and 478 at Michigan Medicine, 348 (34.3%) and 121 (25.3%) developed AKI, respectively. No variants exceeded genome-wide significance (p −8) threshold, however, six previously unreported variants exceeded the suggestive threshold (p −6). Notable variants detected include: 1) rs74637005, located in the exonic region of NFU1 and 2) rs17438465, located between EVX1 and HIBADH. We failed to replicate variants from prior unbiased studies of post-surgical acute kidney injury. Polygenic risk was not significantly associated with post-surgical acute kidney injury in any of the models, however, case duration (aOR = 1.002, 95% CI 1.000–1.003, p = 0.013), diabetes mellitus (aOR = 2.025, 95% CI 1.320–3.103, p = 0.001), and valvular disease (aOR = 0.558, 95% CI 0.372–0.835, p = 0.005) were significant in the full model.Conclusion: Polygenic risk score was not significantly associated with cardiac surgery-associated acute kidney injury and acute kidney injury may have a low heritability in this population. These results suggest that susceptibility is only minimally influenced by baseline genetic predisposition and that clinical risk factors, some of which are modifiable, may play a more influential role in predicting this complication. The overall impact of genetics in overall risk for cardiac surgery-associated acute kidney injury may be small compared to clinical risk factors.</p