Observations of Low-Latitude Plasma Density Enhancements and their Associated Plasma Drifts

Plasma density structures are frequently encountered in the nighttime low-latitude ionosphere by probes on the Communication/Navigation Outage Forecasting System (C/NOFS) satellite. Of particular interest to us here are plasma density enhancements, which are typically observed +/- 15 deg away from the magnetic equator. The low inclination of the C/NOFS satellite offers an unprecedented opportunity to examine these structures and their associated electric fields and plasma velocities, including their field-aligned components, along an east-west trajectory. Among other observations, the data reveal a clear asymmetry in the velocity structure within and around these density enhancements. Previous observations have shown that the peak change in drift velocity associated with a density enhancement occurs simultaneously both perpendicular and parallel to the magnetic field, while the 1results in this paper show that the peak change in parallel fl ow typically occurs 25-100 km to the east of the peak perpendicular ow. We discuss this and other aspects of the observations in relation to the characteristics of the plasma depletions formed near the magnetic equator detected by the same probes on the C/NOFS satellite and to previous observations and theories

Ground and Space-Based Measurement of Rocket Engine Burns in the Ionosphere

On-orbit firings of both liquid and solid rocket motors provide localized disturbances to the plasma in the upper atmosphere. Large amounts of energy are deposited to ionosphere in the form of expanding exhaust vapors which change the composition and flow velocity. Charge exchange between the neutral exhaust molecules and the background ions (mainly O+) yields energetic ion beams. The rapidly moving pickup ions excite plasma instabilities and yield optical emissions after dissociative recombination with ambient electrons. Line-of-sight techniques for remote measurements rocket burn effects include direct observation of plume optical emissions with ground and satellite cameras, and plume scatter with UHF and higher frequency radars. Long range detection with HF radars is possible if the burns occur in the dense part of the ionosphere. The exhaust vapors initiate plasma turbulence in the ionosphere that can scatter HF radar waves launched from ground transmitters. Solid rocket motors provide particulates that become charged in the ionosphere and may excite dusty plasma instabilities. Hypersonic exhaust flow impacting the ionospheric plasma launches a low-frequency, electromagnetic pulse that is detectable using satellites with electric field booms. If the exhaust cloud itself passes over a satellite, in situ detectors measure increased ion-acoustic wave turbulence, enhanced neutral and plasma densities, elevated ion temperatures, and magnetic field perturbations. All of these techniques can be used for long range observations of plumes in the ionosphere. To demonstrate such long range measurements, several experiments were conducted by the Naval Research Laboratory including the Charged Aerosol Release Experiment, the Shuttle Ionospheric Modification with Pulsed Localized Exhaust experiments, and the Shuttle Exhaust Ionospheric Turbulence Experiments

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

NACA Technical Notes

Note presenting a basic theory of generalized linearized supersonic conical flow for both inside and outside the Mach cone, which was developed and applied to several specific problems including unsteady-flow conditions. A triangular lifting wing in pitching and rolling with both subsonic and supersonic leading edges was investigated and pressure coefficients were obtained

Aerodynamic Design and Testing of an Axial Flow Compressor With Pressure Ratio of 23.3:1 for the LM2500؉ Gas Turbine

The LM2500ϩ gas turbine, rated between 39, 000-40,200 shaft horsepower (shp

From research to field action: example of the fight against cholera in the Democratic Republic of Congo

The Democratic Republic of Congo (DRC) is the country in the world which reported the highest number of cholera cases to WHO from 2002 to 2007 (128 936 cases out of a worldwide 902 071 cases). We, therefore, implemented research work which intends to understand the epidemiology of cholera in the DRC and to ensure improvements in the strategy to fight against cholera. This broad study enabled us to accurately determine the cholera epidemic’s mechanisms on different scales; to identify the source zones of the disease, and the groups of populations acting as vectors of the spread. It was then possible to demonstrate the role of “sanctuary”, played by some suburbs of lakeside cities. A collaborative network, including several scientific institutions in Europe and in the DRC, local and national government administrations in the field of public health and sanitation, international agencies, NGOs and private foundations, was progressively set up. Following the conclusions of our epidemiological studies, a drastic change of strategy was proposed: the limited curative approach on the one hand, the few existing water/sanitation programs on the other hand, have been merged in a global approach involving a larger scale water and sanitation infrastructure improvement, environmental protection, hygiene awareness and medical surveys targeting a few focus areas playing a central role in the epidemics. In conclusion, by better targeting intervention zones, one can gather human and technical resources previously scattered on the vast territory of the DRC. The strategy presented here revives the hope to eliminate cholera in the DRC.<br>La République Démocratique du Congo (RDC) est le pays qui a déclaré le plus grand nombre de cas de choléra à l’OMS entre 2002 et 2007 (128 936 cas sur un nombre total de 902 071 de cas dans le monde). Face à cette situation, nous avons mis en œuvre un travail de recherche qui vise à comprendre l’épidémiologie du choléra en RDC et à améliorer la stratégie mise en œuvre pour combattre cette maladie. Cette vaste étude nous a permis de déterminer avec précision les mécanismes de l’épidémie de choléra à différentes échelles ; d’identifier les zones sources de la maladie et les groupes de population agissant comme vecteurs de propagation de celle-ci. Nous avons alors pu démontrer le rôle de « réserve » joué par certaines banlieues de villes situées sur les rives des lacs. Un réseau collaboratif associant plusieurs institutions scientifiques en Europe et en RDC, des administrations gouvernementales au niveau local et national dans le domaine de la santé publique et de l’assainissement, des agences internationales, des ONG et des fondations privées, a été progressivement mis en place. Suite aux conclusions de nos études épidémiologiques, un changement radical de stratégie a été proposé : l’approche curative limitée et les quelques programmes eau/assainissement existants ont été regroupés dans une approche globale impliquant une amélioration des infrastructures d’eau et d’assainissement à plus grande échelle ; une protection de l’environnement ; une prise de conscience des conditions d’hygiène ; et des études médicales ciblées sur quelques domaines jouant un rôle central dans les épidémies. En conclusion, un meilleur ciblage des zones d’intervention a permis de regrouper les ressources humaines et techniques précédemment dispersées sur le vaste territoire de la RDC. La stratégie présentée ici ravive l’espoir d’éradiquer le choléra en RDC.<br>La República Democrática del Congo (RDC) es el país del mundo que notificó a la OMS el número más alto de casos de cólera entre 2002 y 2007 (128.936 casos de los 902.071 que hay en todo el mundo). Pusimos en marcha, por lo tanto, un trabajo de investigación que pretende comprender la epidemiología del cólera en la RDC y asegurar mejoras en la estrategia para luchar contra el cólera. Este amplio estudio nos permitió determinar exactamente los mecanismos de la epidemia del cólera a diferentes escalas, identificar las zonas de origen de la enfermedad, y los grupos de poblaciones que actúan como portadores de la propagación. Fue entonces posible demostrar el papel de &#34;refugio&#34;, jugado por algunos barrios periféricos de ciudades ribereñas. Progresivamente se fue estableciendo una red de colaboración, que incluye varias instituciones científicas en Europa y en la RDC, administraciones gubernamentales locales y nacionales en el campo del saneamiento y la salud pública, agencias internacionales, ONGs y fundaciones privadas. Tras las conclusiones de nuestros estudios epidemiológicos, se propuso un cambio drástico de estrategia: el enfoque curativo limitado por una parte y los escasos programas de agua/saneamiento existentes por otra parte, se han fusionado en un enfoque global que implica una mejora de las infraestructuras de agua y saneamiento a gran escala, protección ambiental, concienciación sobre la higiene e investigaciones médicas que se centran en unas pocas áreas de atención que juegan un papel central en las epidemias. En conclusión, centrándonos mejor en las zonas de intervención, uno puede unir recursos humanos y técnicos anteriormente dispersados en el vasto territorio de la RDC. La estrategia presentada aquí reactiva la esperanza de eliminar el cólera en la RDC

Éthique de la recherche : réglementations françaises et applications en oncologie radiothérapie

International audienc