NASA's Robotic Lunar Lander Development Program

NASA Marshall Space Flight Center and the Johns Hopkins University Applied Physics Laboratory have developed several mission concepts to place scientific and exploration payloads ranging from 10 kg to more than 200 kg on the surface of the moon. The mission concepts all use a small versatile lander that is capable of precision landing. The results to date of the lunar lander development risk reduction activities including high pressure propulsion system testing, structure and mechanism development and testing, and long cycle time battery testing will be addressed. The most visible elements of the risk reduction program are two fully autonomous lander flight test vehicles. The first utilized a high pressure cold gas system (Cold Gas Test Article) with limited flight durations while the subsequent test vehicle, known as the Warm Gas Test Article, utilizes hydrogen peroxide propellant resulting in significantly longer flight times and the ability to more fully exercise flight sensors and algorithms. The development of the Warm Gas Test Article is a system demonstration and was designed with similarity to an actual lunar lander including energy absorbing landing legs, pulsing thrusters, and flight-like software implementation. A set of outdoor flight tests to demonstrate the initial objectives of the WGTA program was completed in Nov. 2011, and will be discussed

Prefoldin Protects Neuronal Cells from Polyglutamine Toxicity by Preventing Aggregation Formation

Huntington disease is caused by cell death after the expansion of polyglutamine (polyQ) tracts longer than similar to 40 repeats encoded by exon 1 of the huntingtin (HTT) gene. Prefoldin is a molecular chaperone composed of six subunits, PFD1-6, and prevents misfolding of newly synthesized nascent polypeptides. In this study, we found that knockdown of PFD2 and PFD5 disrupted prefoldin formation in HTT-expressing cells, resulting in accumulation of aggregates of a pathogenic form of HTT and in induction of cell death. Dead cells, however, did not contain inclusions of HTT, and analysis by a fluorescence correlation spectroscopy indicated that knockdown of PFD2 and PFD5 also increased the size of soluble oligomers of pathogenic HTT in cells. In vitro single molecule observation demonstrated that prefoldin suppressed HTT aggregation at the small oligomer (dimer to tetramer) stage. These results indicate that prefoldin inhibits elongation of large oligomers of pathogenic Htt, thereby inhibiting subsequent inclusion formation, and suggest that soluble oligomers of polyQ-expanded HTT are more toxic than are inclusion to cells

Anomalous Plasma Transport in the Stochastic Magnetic Field

The anomalous transport of a high temperature plasma in the region of stochastic magnetic field is studied. Toroidal plasmas, such as tokamak's, are considered. Using the kinetic equation for plasma particles in the stochastic magnetic field, the plasma transport matrix in the stochastic region is formulated. A quasilinear approximation for the diffusivity of the magnetic field line D_M is used. The shifted Maxwellian which includes the mean velocity and the self-consistent electric potential is assumed. By use of this transport matrix the radial electric field formation, which is generated by ambipolar condition, and the associated temperature distribution in the stochastic region is obtained. The temperature distribution in the stochastic region becomes flat because of the rapid temperature diffusion. The radial electric field is formed in the stochastic region and its magnitude is found to depend on the value of D_M, and on the conditions of the heat fluxes and temperature gradients of electrons and ions in the nonstochastic region

Plasma Transport Induced by the Stochastic Magnetic Field

The anomalous plasma transport induced by the stochastic magnetic field is studied to understand the disruption phenomena in the tokamak plasma. At first, the transport matrix which indicate the plasma transport in the stochastic magnetic field is formulated. For the formulation, the quasi-linear approximation for the diffusivity of the stochastic magnetic field line is used and the shifted Maxwellian is assumed to the particle distribution. Using this transport matrix the radial electric field formation, which is generated by the ambipolar condition,and the associated temperature profile is obtained. The temperature profile in the stochastic magnetic field becomes flat because of. the rapid temperature diffusion. Next the temperature crash, i.e., the sawtooth oscillation and the giant ELM, is analyzed using the turbulence-turbulence transition model, which describes the transition between the state of the electrostatic turbulence and that of the electromagnetic turbulence. This transition has a hysteresis characteristics. When the state changes to the electromagnetic inode, the stochastic magnetic field appears and the temperature transport is enhanced. This transition model is included in the 1-D transport equation. To calculate this transport equation numerically the crash of the temperature profile and the propagation of the crash front (avalanche) are realized by this model. The collapse without a precursor oscillation is revealed

A vanished gastric gastrointestinal stromal tumor

Abstract Background Local resection is the standard treatment for gastrointestinal stromal tumors (GISTs). Laparoscopic and endoscopic cooperative surgery (LECS) is a minimally invasive surgery used to resect GISTs. Herein, we report an extremely rare case of a gastric GIST that grossly vanished during LECS. Case presentation A 50-year-old Japanese female was referred to our hospital after an abnormality was detected during an esophagogastroduodenoscopy (EGD) at her annual health checkup. Based on EGD, endoscopic ultrasound (EUS), and computer tomography (CT) findings, the patient was diagnosed with a 50-mm submucosal tumor (SMT) with intraluminal growth on the anterior wall of the lesser curvature of the upper body of the stomach. We routinely use LECS to treat the intraluminal growth type of GISTs. During the intraoperative endoscopy, the intraluminal submucosal tumor, which was detected preoperatively, had vanished. A red-white scar was observed in the regressed tumor region. LECS was performed by resecting at a distance away from the scar tissue and closing the gastric wall with intracavitary sutures. In the evaluation from the tumor section view of the original resected specimen, a 22 × 14 × 8 mm lobular neoplasm was observed that was predominantly located in the gastric submucosa to the muscularis propia. Pathological findings confirmed the diagnosis of GIST with intermediate risk indicated by the Fletcher classification. The patient continued postoperative adjuvant chemotherapy with imatinib and no recurrence was detected over 12 months after surgery. Conclusion LECS was performed on the vanished gastric GIST, providing the best surgical treatment and leading to an accurate diagnosis and optimal postoperative care