Flight Measurements of the Effect of a Controllable Thrust Reverser on the Flight Characteristics of a Single-Engine Jet Airplane

A flight investigation was undertaken to determine the effect of a fully controllable thrust reverser on the flight characteristics of a single-engine jet airplane. Tests were made using a cylindrical target-type reverser actuated by a hydraulic cylinder through a "beep-type" cockpit control mounted at the base of the throttle. The thrust reverser was evaluated as an in-flight decelerating device, as a flight path control and airspeed control in landing approach, and as a braking device during the ground roll. Full deflection of the reverser for one reverser configuration resulted in a reverse thrust ratio of as much as 85 percent, which at maximum engine power corresponded to a reversed thrust of 5100 pounds. Use of the reverser in landing approach made possible a wide selection of approach angles, a large reduction in approach speed at steep approach angles, improved control of flight path angle, and more accuracy in hitting a given touchdown point. The use of the reverser as a speed brake at lower airspeeds was compromised by a longitudinal trim change. At the lower airspeeds and higher engine powers there was insufficient elevator power to overcome the nose-down trim change at full reverser deflection

Sampling considerations when analyzing micrometric-sized particles in a liquid jet using laser induced breakdown spectroscopy

International audiencePollution of water is a matter of concern all over the earth. Particles are known to play an important role in the transportation of pollutants in this medium. In addition, the emergence of new materials such as NOAA (Nano-Objects, their Aggregates and their Agglomerates) emphasizes the need to develop adapted instruments for their detection. Surveillance of pollutants in particulate form in waste waters in industries involved in nanopartide manufacturing and processing is a telling example of possible applications of such instrumental development. The LIBS (laser-induced breakdown spectroscopy) technique coupled with the liquid jet as sampling mode for suspensions was deemed as a potential candidate for on-line and real time monitoring. With the final aim in view to obtain the best detection limits, the interaction of nanosecond laser pulses with the liquid jet was examined. The evolution of the volume sampled by laser pulses was estimated as a function of the laser energy applying conditional analysis when analyzing a suspension of micrometric-sized particles of borosilicate glass. An estimation of the sampled depth was made. Along with the estimation of the sampled volume, the evolution of the SNR (signal to noise ratio) as a function of the laser energy was investigated as well. Eventually, the laser energy and the corresponding fluence optimizing both the sampling volume and the SNR were determined. The obtained results highlight intrinsic limitations of the liquid jet sampling mode when using 532 nm nanosecond laser pulses with suspensions

Caracterisation agromorphologique, chimique et biochimique des noix brutes de trois provenances d’anacardiers (Anacardium occidentale L.) au Sud du Senegal

La sécurité alimentaire est l’une des préoccupations majeures des hommes dans le monde. Pour l’atteindre, les populations rurales tirent une grande partie de leurs alimentations dans les Produits Forestiers Non Ligneux. Anacardium occidentale L., une espèce agroforestière très prisée n’est pas en reste. Cependant, des études sur la valeur alimentaire et nutritionnelle de ses noix sont limitées et restent parcellaires. L’objectif de cette recherche est d’évaluer les teneurs en éléments nutritifs des noix brutes de Anacardium occidentale L. collectées à Ziguinchor, Sédhiou et Kolda. Pour ce faire, dans chaque zone, trois kilogrammes de noix ont été prélevées de manière aléatoire dans différents lieux de stockage. Puis les mensurations ont porté sur 450 noix par provenance. Les noix ont été ensuite décortiquées puis soumises à une analyse minérale (chimique et biochimique). Une analyse uni et multivariée a été effectuée à l’aide de XLSTAT 6.0. L’analyse a montré l’existence d’une variabilité des caractéristiques entre les provenances. Une corrélation forte, significative mais négative a été détectée entre le poids des amandes et la cellulose brute, ce qui signifierait que les amandes de petite taille sont plus sucrées. A travers cette étude, plusieurs possibilités s’offrent aux différents acteurs de la chaine de valeur anacarde. English title: Agromorphological, chemical and biochemical characterization of <I>Anacardium occidentale L.</I> in Sud Senegal Food security is one of the major concerns of people around the world. To achieve this, rural populations derive a large part of their food from Non-Wood Forest Products. Anacardium occidentale L., a highly prized agroforestry species, is not to be outdone. However, studies on the food and nutritional value of its nuts are limited and remain fragmented. The objective of this research is to evaluate the nutrient content of raw nuts of Anacardium occidentale L. collected in Ziguinchor, Sédhiou and Kolda. To do this, in each area, three kilograms of nuts were taken at random from  different storage locations. Then the measurements were carried out on 450 nuts per provenance. The nuts were then shelled and then subjected to mineral analysis (chemical and biochemical). Univariate and multivariate analysis was performed using XLSTAT 6.0. The analysis showed the  existence of variability in characteristics between provenances. A strong, significant but negative correlation was detected between the weight of the almonds and the crude fiber, which would mean that the small almonds are sweeter. Through this study, several possibilities are available to the various players in the cashew value chain

Mechanisms underlying the endothelium-dependent vasodilatory effect of an aqueous extract of Elaeis guineensis Jacq. (Arecaceae) in porcine coronary artery rings

This study was undertaken to investigate the vasodilatory effect of an aqueous extract of Elaeis guineensis Jacq (EGE) in the porcine coronary artery and elicit its possible mechanism(s) of action. Vascular effects of crude extract of dried and powdered leaves of Elaeis guineensis were evaluated on isolated coronary arteries on organ chambers. Determination of eNOS expression and the phosphorylation level of eNOS were  determined by Western blot analysis. In the presence of indomethacin,  EGE caused pronounced relaxations in endothelium-intact but not in endothelium-denuded coronary artery rings. Relaxations to EGE were significantly reduced by Nω-nitro-L-arginine (L-NA, a competitive inhibitor of NO synthase), slightly but not significantly by charybdotoxin plus apamin (two potent inhibitors of EDHF-mediated responses) and abolished by the combination of L-NA and charybdotoxin plus apamin. Relaxations to EGE were abolished by the membrane permeant, SOD mimetic, MnTMPyP, and significantly reduced by wortmannin, an inhibitor of PI3-kinase. Exposure of endothelial cells to EGE increased the phosphorylation level of eNOS at Ser1177 in a time and concentration-dependent manner. MnTMPyP abolished the EGE-induced phosphorylation of eNOS. In conclusion, the obtained data indicate that EGE induces pronounced endothelium-dependent relaxations of the porcine coronary artery, which involve predominantly NO. The stimulatory effect of EGE on eNOS involves the redox-sensitive phosphorylation of eNOS at Ser1177 most likely via the PI3-kinase pathway

Transient Hypoxia Alters Striatal Catecholamine Metabolism in Immature Brain: An In Vivo Microdialysis Study

Microdialysis probes were inserted bilaterally into the striatum of 7-day-old rat pups (n = 30) to examine extracellular fluid levels of dopamine, its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA). The dialysis samples were assayed by HPLC with electrochemical detection. Baseline levels, measured after a 2-h stabilization period, were as follows: dopamine, not detected; DOPAC, 617 ± 33 fmol/min; HVA, 974 ± 42 fmol/min; and 5-HIAA, 276 ± 15 fmol/min. After a 40-min baseline sampling period, 12 animals were exposed to 8% oxygen for 120 min. Hypoxia produced marked reductions in the striatal extracellular fluid levels of both dopamine metabolites ( p < 0.001 by analysis of variance) and a more gradual and less prominent reduction in 5-HIAA levels ( p < 0.02 by analysis of variance), compared with controls (n = 12) sampled in room air. In the first hour after hypoxia, DOPAC and HVA levels rose quickly, whereas 5-HIAA levels remained suppressed. The magnitude of depolarization-evoked release of dopamine (elicited by infusion of potassium or veratrine through the microdialysis probes for 20 min) was evaluated in control and hypoxic animals. Depolarization-evoked dopamine efflux was considerably higher in hypoxic pups than in controls: hypoxic (n = 7), 257 ± 32 fmol/min; control (n = 12), 75 ± 14 fmol/min ( p < 0.001 by analysis of variance). These data demonstrate that a brief exposure to moderate hypoxia markedly disrupts striatal catecholamine metabolism in the immature rodent brain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66218/1/j.1471-4159.1990.tb01914.x.pd

High-quality genome sequence and description of Paenibacillus dakarensis sp. nov.

AbstractStrain FF9T was isolated in Dakar (Senegal) from a blood-culture taken from a 16-month-old child. MALDI-TOF analysis did not allow for identification. After sequencing, strain FF9T exhibited 98.18% similarity with the 16SrRNA sequence of Paenibacillus uliginis. A polyphasic study of phenotypic and genomic analyses showed that strain FF9T is Gram variable, catalase-positive, and presents a genome of 4,569,428 bp (one chromosome but no plasmid) with 4,427genes (4,352 protein-coding and 75 RNA genes (including 3 rRNA operons). The G+C content is 45.7%. On the basis of these genomic and phenotypic data analyses, we propose the creation of Paenibacillus dakarensis strain FF9T

Integration of juvenile habitat quality and river connectivity models to understand and prioritise the management of barriers for Atlantic salmon populations across spatial scales

Thanks to the Scottish Government Hydro Nation Scholarship programme for funding WBB. Authors from Marine Scotland Science Freshwater Fisheries Laboratories delivered this work through Service Level Agreement FW02G. Some map features are based on digital spatial data licensed from CEH, NERC© Crown Copyright and database right (2018), all rights reserved. Ordnance Survey License number 100024655. Catchment boundaries were from SEPA (2009). The Obstacles to Fish Migration dataset is from SEPA. The authors thank the two anonymous referees for their feedback on the manuscript.Peer reviewedPostprin

Viral particles of the endogenous retrovirus ZAM from Drosophila melanogaster use a pre-existing endosome/exosome pathway for transfer to the oocyte

BACKGROUND: Retroviruses have evolved various mechanisms to optimize their transfer to new target cells via late endosomes. Here, we analyzed the transfer of ZAM, a retroelement from Drosophila melanogaster, from ovarian follicle cells to the oocyte at stage 9–10 of oogenesis, when an active yolk transfer is occurring between these two cell types. RESULTS: Combining genetic and microscopic approaches, we show that a functional secretory apparatus is required to tether ZAM to endosomal vesicles and to direct its transport to the apical side of follicle cells. There, ZAM egress requires an intact follicular epithelium communicating with the oocyte. When gap junctions are inhibited or yolk receptors mutated, ZAM particles fail to sort out the follicle cells. CONCLUSION: Overall, our results indicate that retrotransposons do not exclusively perform intracellular replication cycles but may usurp exosomal/endosomal traffic to be routed from one cell to another