Boundary-Layer Instability Measurements in a Mach-6 Quiet Tunnel

Several experiments have been performed in the Boeing/AFOSR Mach-6 Quiet Tunnel at Purdue University. A 7 degree half angle cone at 6 degree angle of attack with temperature-sensitive paint (TSP) and PCB pressure transducers was tested under quiet flow. The stationary crossflow vortices appear to break down to turbulence near the lee ray for sufficiently high Reynolds numbers. Attempts to use roughness elements to control the spacing of hot streaks on a flared cone in quiet flow did not succeed. Roughness was observed to damp the second-mode waves in areas influenced by the roughness, and wide roughness spacing allowed hot streaks to form between the roughness elements. A forward-facing cavity was used for proof-of-concept studies for a laser perturber. The lowest density at which the freestream laser perturbations could be detected was 1.07 x 10(exp -2) kilograms per cubic meter. Experiments were conducted to determine the transition characteristics of a streamwise corner flow at hypersonic velocities. Quiet flow resulted in a delayed onset of hot streak spreading. Under low Reynolds number flow hot streak spreading did not occur along the model. A new shock tube has been built at Purdue. The shock tube is designed to create weak shocks suitable for calibrating sensors, particularly PCB-132 sensors. PCB-132 measurements in another shock tube show the shock response and a linear calibration over a moderate pressure range

(Homo)glutathione Deficiency Impairs Root-knot Nematode Development in Medicago truncatula

Root-knot nematodes (RKN) are obligatory plant parasitic worms that establish and maintain an intimate relationship with their host plants. During a compatible interaction, RKN induce the redifferentiation of root cells into multinucleate and hypertrophied giant cells essential for nematode growth and reproduction. These metabolically active feeding cells constitute the exclusive source of nutrients for the nematode. Detailed analysis of glutathione (GSH) and homoglutathione (hGSH) metabolism demonstrated the importance of these compounds for the success of nematode infection in Medicago truncatula. We reported quantification of GSH and hGSH and gene expression analysis showing that (h)GSH metabolism in neoformed gall organs differs from that in uninfected roots. Depletion of (h)GSH content impaired nematode egg mass formation and modified the sex ratio. In addition, gene expression and metabolomic analyses showed a substantial modification of starch and γ-aminobutyrate metabolism and of malate and glucose content in (h)GSH-depleted galls. Interestingly, these modifications did not occur in (h)GSH-depleted roots. These various results suggest that (h)GSH have a key role in the regulation of giant cell metabolism. The discovery of these specific plant regulatory elements could lead to the development of new pest management strategies against nematodes

Techniques for application of roughness for manipulation of second-mode waves on a flared cone at Mach 6

Experimental validation of physics-based transition models is essential to improving the state of the art of hypersonic vehicle design. This research focuses on one aspect of this problem, which is the effect of surface roughness on the non-linear breakdown of second-mode waves in hypersonic boundary layers. A flared cone was designed to allow non-linear growth of second-mode waves to sufficient amplitudes to lead to transition under quiet flow in the Boeing/AFOSR Mach 6 Quiet Tunnel. The non-linear breakdown process is characterized by a set of streamwise streaks of increased heating, followed by the onset of turbulence. The location of the streaks is related to small amounts of upstream surface roughness. Techniques for applying and fabricating surface roughness were developed. These are to be used to manipulate this breakdown process. While certain types of roughness have been used to introduce streamwise vorticity in other flows at low speeds, it was unknown what types of roughness would work in the present case. The effects of the new roughness types were analyzed through pressure measurements and global heat transfer visualization using temperature sensitive paint. None of the new roughness types was able to directly control the spanwise periodicity of the streaks, but two types were identified as good candidates for future testing. More work is required to develop a suitable technique for fabricating and applying small roughness

The Bernhard Nocht Institute: 100 years of tropical medicine in Hamburg

The Bernhard Nocht Institute (BNI) is a four months younger and much smaller sibling of the Instituto Oswaldo Cruz. It was founded on 1 October 1900 as an Institut für Schiffs- und Tropenkrankheiten (Institute for Maritime and Tropical Diseases) and was later named after its founder and first director Bernhard Nocht. Today it is the Germany's largest institution for research in tropical medicine. It is a government institution affiliated to the Federal Ministry of Health of Germany and the Department of Health of the State of Hamburg. As the center for research in tropical medicine in Germany the BNI is dedicated to research, training and patient care in the area of human infectious diseases, which are of particular relevance in the tropics. It is the primary mission of the BNI to develop means to the control of these diseases. Secondary missions are to provide expertise for regional and national authorities and to directly and indirectly improve the health care for national and regional citizens in regard to diseases of the tropics

GUIDELINE FOR THE MANAGEMENT OF BILE DUCT CANCERS BY THE BRAZILIAN GASTROINTESTINAL TUMOR GROUP

ABSTRACT The Brazilian Gastrointestinal Tumor Group developed guidelines for the surgical and clinical management of patients with billiary cancers. The multidisciplinary panel was composed of experts in the field of radiology, medical oncology, surgical oncology, radiotherapy, endoscopy and pathology. The panel utilized the most recent literature to develop a series of evidence-based recommendations on different treatment and diagnostic strategies for cholangiocarcinomas and gallbladder cancers