Multidecadal Analysis of an Engineered River System Reveals Challenges for Model-Based Design of Human Interventions

Hydraulic models were used in practice to predict the effect of human intervention during extreme conditions. However, the accuracy of such predictions remains untested. In this study, we compare a simulated trend in water levels covering a twenty-year period of large-scale human intervention with a thirty-year observational record. The results show that the observed water levels display a linearly decreasing trend attributed to channel bed erosion. A deviation from this trend, which would be an indication of the effect of human intervention, was not observed. We propose that the most likely explanation for this is that any effect observable at lower discharge is hidden in the uncertainty of the rating curve. Given the inherent uncertainties associated with making predictions about a changing system for conditions with a low period of return, we argue that model uncertainty should be considered in intervention design.

Sediment displacement evolution after dam removal in a mountain river (Oioki dam, Leitzaran River)

<p>Bedload sediment transport was monitored from 2016 to 2020 in the Leitzaran River, in a reach affected by the removal of 7-meters high dam (Oioki dam). The removal was accomplished in two phases, the 3 first meters were removed in September 2018 and the second phase (September 2019) involved the removal of the remaining 4 meters. The study area was divided into three subreaches: control (unaffected by the dam), upstream and downstream of the dam. A sample of 300 RFID-tagged stones were seeded every year (100 at each reach).. Prior to this, the grain-size distribution of the surface sediment was characterized using the Wolman method. Then, the grain-size chosen for the tracer stones was distributed according to three Wentworth intervals: that corresponding to the surface d<sub>50</sub>, d<sub>50</sub>+1 (immediate upper interval), and d<sub>50</sub>-1 (immediate lower interval). It was not possible to follow completely, and the lower interval had to be dismissed as the sediment was very small or narrow to insert the tracer.</p><p>We conducted an extensive surveying field campaign every summer.</p><p>The number of retrieved tracers was relatively high, around 40-70% (considering all field campaigns), although with differences amongst the different sub-reaches. The obtained results were organized by displacements and volumes of sediment moved. The maximum (3,500 meters) and higher mean displacement (~1,550 meters) were registered in the hydrologic year 2019/20. These values are from the upstream reach of the dam and match simultaneously with (i) the whole removal of the dam, and (ii) the period showing a lower discharge (note the critical discharge for the movement of our particles is ~25-30 m<sup>3</sup>·s<sup>-1</sup> (d<sub>50</sub> = 64.0≥Ø<90.5 mm); mean discharge and peak flow from 2013 to 2020 were ~5.3 m<sup>3</sup>·s<sup>-1</sup> and ~125.0 m<sup>3</sup>·s<sup>-1</sup>, respectively and at the end of the watershed).</p><p>We also estimated the bulk bedload volumes during the time spanned by this research and we report how the hydrologic year 2019/20 was the more active in terms of displaced volumes, moving up to 27,500 tons in the upstream reach. In fact, this year also presents the maximum for the downstream reach.</p><p>At this moment, besides the raw data of displacements and volumes, our observations highlight how the fact that a copious load of sediment was made available with the dam removal seemed to be more determinant than the magnitude of the flow to get larger tracer displacements.</p>

Refrigerating fluid with a low global warming potential for automotive air conditioning systems in summer

Refrigerants with low global warming potential (GWP) are much needed in automotive air conditioning systems. This paper compares two refrigerants, R134a (GWP=1300) and R513A (GWP=573) experimentally. The results show that the latter has lower cooling capacity, lower COP and lower discharge temperature than the former, revealing that R513A is a promising replacement of its high GWP partner.

Do Motoneurons Slow With Aging? A Systematic Review And Meta-Analysis With Meta-Regression

Nervous system maladaptation is linked to the loss of muscle force production and motor control with aging. However, the mechanisms specifically underpinning these muscle functional limitations remain unclear. Motoneuron discharge rates are a critical determinant of force production and strongly impact motor control; thus, lower discharge rates could underpin force and physical function losses during aging. The present meta-analysis with meta-regression summarises the findings of studies comparing motoneuron discharge rates between young and older adults and examines whether a muscle's functional role and anatomical location influences discharge rates across contraction intensities during aging. Meta-analysis revealed lower discharge rates in older compared to young adults in lower body flexor (standardised mean difference, SMD=-0.86; 95%CI: -1.20, -0.51; p<0.001) but not extensor (SMD=-0.18; 95%CI: -0.50, 0.15; p=0.29) muscles or upper body muscles (SMD=-0.79; 95%CI: -1.75, 0.18; p=0.11). Meta-regression revealed that the differences in discharge rate between young and older adults increase with contraction intensity in upper body muscles (β=-0.033, p=0.004). These findings suggest that motor function loss with aging might be partly explained by reduced motoneuron discharge rates; however, this decrease varies according to a muscle's anatomical location, functional role, and contraction intensity.

Epidemiological characteristics of COVID-19 in Shenzhen, China: comparison between imported and local cases

Introduction: An unprecedented outbreak of the novel coronavirus disease (COVID-19) has swept across the globe since the end of 2019. Shenzhen confirmed its first imported case from Wuhan on 19 January 2020. However, little is known regarding the epidemiological characteristics of COVID-19 in these imported cities. Methodology: Data of all 417 confirmed cases diagnosed in Shenzhen before 29 February were collected. The epidemiological characteristics of imported and local cases were compared. The resilience to COVID-19 was evaluated by discharge density. Results: All ten districts reported COVID-19 cases by 29 February, including 331 imported and 86 local cases. The Pearson linear correlation model showed the number of confirmed cases (r = 0.990, p < 0.001) as well as incidence of COVID-19 (r = 0.766, p = 0.010) was positively correlated with the gross domestic product of district. Family clusters were more commonly found in local cases. Imported patients had earlier onset (p < 0.001) and diagnosis (p < 0.001), but longer interval from onset to admission (p = 0.030), diagnosis (p = 0.003) and discharge (p = 0.016). Older and severe cases had lower discharge density (0.024 and 0.018, respectively); while cases with subclinical symptoms exhibited higher discharge density (0.052). Conclusions: COVID-19 patients were predominantly imported cases in Shenzhen and the spatial distribution was closely related to district GDP. Imported and local cases differed in the intervals from onset to admission, diagnosis and discharge. Moreover, family-based transmission should not be ignored, especially in local cases.

Discharge Hemoglobin Association with Long-Term Outcomes of ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Background. Anemia following acute myocardial infarction (AMI) is associated with poor outcomes. While previous studies in patients with AMI have focused on anemia at admission, we hypothesized that hemoglobin (Hb) decline during hospitalization and lower discharge Hb would be associated with greater long-term mortality in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Methods. We analyzed records of 983 STEMI patients who were treated with primary PCI. The primary end point was all-cause mortality at 1 year and 2 years. The relationship between discharge Hb levels, decline in Hb levels, bleeding event classification, and all-cause mortality was determined. Results. Overall, 16.4% of patients had bleeding events, which were classified by the Thrombolysis in Myocardial Infarction (TIMI) score as 7% minimal, 8.6% minor, and 0.9% major. No significant gastrointestinal bleed and cerebral hemorrhage occurred in hospitals among these patients. The incidence rate of the 2-year all-cause mortality increased with severity of the bleeding event score (8.78% for no bleeding vs. 11.59% for minimal bleeding vs. 20.24% for minor bleeding vs. 55.56% for major bleeding, P<0.001). Discharge Hb was significantly associated with 2-year mortality in an unadjusted model (hazard ratio (HR) per 1 g/L decrease in discharge Hb = 1.020, 95% confidence interval (CI): 1.006–1.034, P=0.004) and in a confounder-adjusted model (HR per 1 g/L decrease in discharge Hb = 1.024, 95% CI: 1.011–1.037, P<0.001). The odds ratio (OR) for all-cause mortality at 2 years for participants with Hb below the twentieth percentile was 3.529 (95% CI: 1.976–6.302) and 2.968 (95% CI: 1.614–5.456) after adjustment for age and gender and 2.485 (95% CI: 1.310–4.715) after adjustment for all covariates. Conclusions. In this population of patients hospitalized for STEMI, all-cause mortality increased with lower discharge Hb, and discharge Hb was a significant predictor of mortality risk.

Seed conditioning process in the sanitary quality of marandu grass seeds

The purpose of seed conditioning process is to separate seeds and their associated structures into different fractions and retain only good and healthy seeds. Thus, the aim of this study was to evaluate the effects the stages of seed conditioning have on the sanitary quality of marandu grass seeds. The seeds were sampled before and during the seed conditioning process, i.e., after exiting the air-screen cleaner and sieves (seeds discharged from the top, middle and bottom sieves), the first gravity separator (seeds drifting around the table, upper and intermediate discharge) and second gravity separator (upper, intermediate and lower discharge). The sanitary analysis was performed using the filter paper method with and without surface disinfestation of the seeds, which were incubated at 20±2°C, with a photoperiod of 12 hours for seven days. The experiment was conducted in a completely randomized design, in a 2x6 factorial scheme (surface disinfestation x stages of the seed conditioning process) and ten replications. The data was submitted to analysis of variance, using the F test and, when significant, the means of the treatments were compared using the Tukey test at 5% probability. It was concluded that it is not possible to improve the sanitary quality of marandú grass seeds through the seed conditioning process.

Redox Polymers as Electrode-Active Materials for Batteries

Organic cathode materials are promising candidates for a new generation of ‘green batteries’, since they have low toxicity and can be produced from renewable resources or from petroleum. This review shows that organic redox polymers can show excellent battery performance regarding cycling stability and rate capability, and attractive specific capacities are accessible. Radical polymers and redox polymers based on heteroaromatics demonstrate superior rate capabilities and cycling stabilities at fast C-rates as well as high discharge potentials of 3–4 V versus Li/Li+, while quinone- or imide-based polymers deliver high specific capacities of up to 260 mAh g−1 with stable cycling at moderate C-rates and lower discharge potentials. This review article highlights the underlying design principles showcasing selected examples of well-performing redox polymers.

Race/Ethnicity Matters: Differences in Poststroke Inpatient Rehabilitation Outcomes

Objective: To examine racial/ethnic differ­ences in poststroke inpatient rehabilitation outcomes.Design: Cross-sectional and retrospective study of administrative data across 2002- 2018.Setting: An inpatient rehabilitation facility in Southern California.Participants: 3,876 racial/ethnic people aged ≥ 18 years.Main Outcome Measures: Functional In­dependence Measure (FIM®) and discharge disposition.Results: Participants were non-Hispanic Whites (NHWs, 68.5%), Hispanics (17.1%), non-Hispanic Asians (NHAs, 7.4%), and non-Hispanic Blacks (NHBs, 6.4%) aged 18-102 years (Mage = 68.47±14.66 years; MLOS = 19.47±10.05 days). Above and beyond covariates, multivariate hierarchical regression analyses showed race/ethnicity significantly predicted admission, motor efficiency, and discharge FIM® scores. Compared with NHWs, the Hispanic and NHA groups were associated with lower cognitive, motor, and total FIM® scores at admission; the NHB group was associated with lower motor efficiency, lower discharge motor and total FIM® scores, whereas the Hispanic group was associated with higher discharge total FIM® scores. Lastly, Hispanics had higher odds of a discharge home compared with NHWs.Conclusions: Findings suggest racial/ethnic differences exist in poststroke rehabilitation outcomes. Ethn Dis. 2019;29(4):599-608; doi:10.18865/ed.29.4.599

TO THE QUESTION OF CLEANING OF EXHAUST OIL FROM NON-SOLUBLE IMPURITIES IN A HYDROCYCLONE

The possibility of using hydrocyclone plants for cleaning used oils is considered. The dependence of the degree of purification of waste oil on insoluble impurities is determined theoretically, determined by the mass content of particles in the oil flow removed through the lower drainage hole, from the time of the particle in the hydrocyclone and the radius of the surface of zero axial velocity, which determines the separation of the oil flow and the entrainment of particles through the upper or lower discharge holes.