Full-Scale Turbofan Engine Noise-Source Separation Using a Four-Signal Method

Contributions from the combustor to the overall propulsion noise of civilian transport aircraft are starting to become important due to turbofan design trends and expected advances in mitigation of other noise sources. During on-ground, static-engine acoustic tests, combustor noise is generally sub-dominant to other engine noise sources because of the absence of in-flight effects. Consequently, noise-source separation techniques are needed to extract combustor-noise information from the total noise signature in order to further progress. A novel four-signal source-separation method is applied to data from a static, full-scale engine test and compared to previous methods. The new method is, in a sense, a combination of two- and three-signal techniques and represents an attempt to alleviate some of the weaknesses of each of those approaches. This work is supported by the NASA Advanced Air Vehicles Program, Advanced Air Transport Technology Project, Aircraft Noise Reduction Subproject and the NASA Glenn Faculty Fellowship Program

Mapping Thunder Sources by Inverting Acoustic and Electromagnetic Observations

We present a new method of locating current flow in lightning strikes by inversion of thunder recordings constrained by Lightning Mapping Array observations. First, radio frequency (RF) pulses are connected to reconstruct conductive channels created by leaders. Then, acoustic signals that would be produced by current flow through each channel are forward modeled. The recorded thunder is considered to consist of a weighted superposition of these acoustic signals. We calculate the posterior distribution of acoustic source energy for each channel with a Markov Chain Monte Carlo inversion that fits power envelopes of modeled and recorded thunder; these results show which parts of the flash carry current and produce thunder. We examine the effects of RF pulse location imprecision and atmospheric winds on quality of results and apply this method to several lightning flashes over the Magdalena Mountains in New Mexico, USA. This method will enable more detailed study of lightning phenomena by allowing researchers to map current flow in addition to leader propagation

Human resources: the Cinderella of health sector reform in Latin America

Human resources are the most important assets of any health system, and health workforce problems have for decades limited the efficiency and quality of Latin America health systems. World Bank-led reforms aimed at increasing equity, efficiency, quality of care and user satisfaction did not attempt to resolve the human resources problems that had been identified in multiple health sector assessments. However, the two most important reform policies – decentralization and privatization – have had a negative impact on the conditions of employment and prompted opposition from organized professionals and unions. In several countries of the region, the workforce became the most important obstacle to successful reform. This article is based on fieldwork and a review of the literature. It discusses the reasons that led health workers to oppose reform; the institutional and legal constraints to implementing reform as originally designed; the mismatch between the types of personnel needed for reform and the availability of professionals; the deficiencies of the reform implementation process; and the regulatory weaknesses of the region. The discussion presents workforce strategies that the reforms could have included to achieve the intended goals, and the need to take into account the values and political realities of the countries. The authors suggest that autochthonous solutions are more likely to succeed than solutions imported from the outside

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council

Antioxidant Rich Diets Are Associated with Increased Verbal Fluency in Young Adults

Research shows that high antioxidant (e.g., vitamin E and beta-carotene) diets are associated with superior performance on verbal fluency and verbal learning tasks. Studies have found that an antioxidant rich diet is related to some cognitive improvements in verbal cognition. However, studies have primarily focused on how nutrition relates to cognition in older adults, and little is known about whether an antioxidant rich diet is related to cognitive performance in adolescents and young adults. The current study aims to investigate how self-reported recent consumption of antioxidant rich diet (foods containing vitamin C, E and beta-carotene) relate to verbal cognitive performance in teens and young adults. The sample included 95 participants aged 16-25 (44% female, 65% white). The Automated Self-Administered 24-Hour Dietary Assessment Tool was administered to assess participant’s food intake within the last 24 hours. Separate hierarchical regressions were conducted to evaluate whether levels of vitamin C, E, and beta-carotene (Step 2) significantly predicted performance on verbal fluency and learning after accounting for age, sex, and race (Step 1). Results showed in step 1 that together sex, race, and age were significantly associated with verbal fluency, R2 = .089, F (3, 91) = 2.975, p = .036. After accounting for demographic variables, vitamin C, E, and beta-carotene were significantly related to verbal fluency, ΔR2 = .067, Fchange(6, 88) = 2.72, p = .018. Antioxidant diet was not significantly associated with initial verbal learning at step 1 (R2 = .012, F (3, 91) = .376) or 2 (ΔR2 = .106, Fchange(6, 88) = 1.964). Consistent with prior studies in older adults, higher intake of antioxidant-rich food was significantly associated with superior performance in verbal fluency in adolescents and young adults. Future studies should consider how other measures of health, such as aerobic fitness, influence the relationship between nutrition and cognitive performance

Effects of 3-week Abstinence from Cannabis on Depression and Anxiety

Research has shown that cannabis users experience greater symptoms of depression after one week of abstinence. The aim of this study is to investigate how abstinence from cannabis over a 3-week period affects depression and anxiety. 87 participants (49 controls and 38 cannabis users) aged 16-25 and balanced for gender (56% male) were included in the study. Controls had fewer than 5 joints and cannabis users had more than 52 joints in the past year. Participants were monitored for abstinence across a 3-week period. The Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI) were used at baseline and after 3 weeks of abstinence to measure symptoms of depression and anxiety. Separate repeated measures ANCOVA were run to examine the interaction between time and group on depression and anxiety while covarying for gender. Cannabis users had higher levels of depression (p=.09) and anxiety at baseline compared to controls. After abstinence, cannabis users experienced a trend of increased depression symptoms but decreased anxiety symptoms. Consistent with the general literature, cannabis users had greater symptoms of anxiety and depression. Further, cannabis users demonstrated recovery in their anxiety symptoms. The increase in depression symptoms is likely reflecting symptoms of prolonged withdrawal from cannabis. Future studies may want to examine a longer period to capture recovery from this withdrawal