Navigation of the TSS-1 mission

The Tethered Satellite System Mission was analyzed to determine its impacts on the Mission Control Center (MCC) Navigation section's ability to maintain an accurate state vector for the Space Shuttle during nominal and off-nominal flight operations. Tether dynamics expected on the Shuttle introduces new phenomena when determining the best estimation of its position and velocity. In the analysis, emphasis was placed on determining the navigation state vectors accuracies resulting when the tether induced forces were and were not modeled as an additional acceleration upon processing tracking measurements around a TSS-1 trajectory. Results of the analyses show that when the forces are not modeled in the state vector generation process, the resulting solution state reflects a solution about the center of gravity of the tethered system and not that of the orbiter. The Navigation team's ability to provide accurate state vector estimates necessary for trajectory planning are impeded. In addition to this consequent, is an impact on Onboard Navigation state vector accuracies. These analyses will show that in order to preserve an accurate state onboard the orbiter a new operational procedure would have to be adopted

The microbiome-gut-brain axis in health and disease

Gut microbes are capable of producing most neurotransmitters found in the human brain. While these neurotransmitters primarily act locally in the gut, modulating the enteric nervous system, evidence is now accumulating to support the view that gut microbes through multiple mechanisms can influence central neurochemistry and behavior. This has been described as a fundamental paradigm shift in neuroscience. Bifidobacteria for example can produce and increase plasma levels of the serotonin precursor tryptophan, which is fundamental in regulating mood, appetite and gastrointestinal function. Certain Lactobacilli have been shown to produce gamma-aminobutyric acid (GABA) and to alter brain GABA receptor expression and behavior. IBS is regarded as the prototypic disorder of the brain-gut-microbiota axis which can be responsive to probiotic therapy. Recently, the concept of a psychobiotic has been introduced in the literature. A psychobiotic is a bacteria which when ingested in adequate amounts can have a positive mental health benefit. Translational studies indicate that certain bacteria may impact upon stress responses and cognitive functioning. Manipulating the gut microbiota with psychobiotics, prebiotics or even antibiotics offers a novel approach to altering brain function and treating gut-brain axis disorders such as depression and autism

Cotton Price Policy and New Cereal Technology in the Malian Cotton Zone

During the last decade, cotton production and area have been declining as a result of depleting soil nutrients and low cotton prices in the cotton zone of Mali. This paper shows that the Malian government’s 2011 policy to increase the farm gate cotton price as a response to world cotton price increase enhances farm income but has less impact on cotton than on maize production. A complementary policy of introducing new sorghum technologies would have an equal impact on farmers’ incomes in the cotton zone of Mali.Cotton prices, improved sorghum technology, discrete stochastic programming, Mali, Agricultural and Food Policy, Farm Management, International Development, Production Economics, Risk and Uncertainty,

Needle Track Seeding of Primary and Secondary Liver Carcinoma After Percutaneous Liver Biopsy

Seeding of tumour in the needle track following percutaneous needle biopsy of liver neoplasms is rarely reported. We describe two such cases following the needle biopsy of an hepatocellular carcinoma and secondary colorectal carcinoma respectively. The risk of needle track recurrence of liver tumours should not be regarded as insignificant. The diagnosis of liver neoplasms may be achieved by non-invasive modalities, and their needle biopsy should be reserved for cases not amenable to surgical resection

Detection of Lead in the Carbon-Rich, Very Metal-Poor Star LP625-44: A Strong Constraint on s-Process Nucleosynthesis at Low Metallicity

We report the detection of the Pb I 4057.8A line in the very metal-poor ([Fe/H]=-2.7), carbon-rich star, LP625-44. We determine the abundance of Pb ([Pb/Fe] = 2.65) and 15 other neutron-capture elements. The abundance pattern between Ba and Pb agrees well with a scaled solar system s-process component, while the lighter elements (Sr-Zr) are less abundant than Ba. The enhancement of s-process elements is interpreted as a result of mass transfer in a binary system from a previous AGB companion, an interpretation strongly supported by radial velocity variations of this system. The detection of Pb makes it possible, for the first time, to compare model predictions of s-process nucleosynthesis in AGB stars with observations of elements between Sr and Pb. The Pb abundance is significantly lower than the prediction of recent models (e.g., Gallino et al. 1998), which succeeded in explaining the metallicity dependence of the abundance ratios of light s-elements (Sr-Zr) to heavy ones (Ba-Dy) found in previously observed s-process-enhanced stars. This suggests that one should either (a) reconsider the underlying assumptions concerning the 13C-rich s-processing site (13C-pocket) in the present models, or (b) investigate alternative sites of s-process nucleosynthesis in very metal-poor AGB stars.Comment: 10 pages, 3 figures, Astrophysical Journal Letters, in pres

The Properties of The Wood-Polystyrene Interphase Determined by Inverse Gas Chromatography

The properties of the interphase in wood-polymer composites are important determinants of the properties of the final composite. This study used inverse gas chromatography (IGC) to measure interphasal properties of composites of polystyrene and two types of wood fiber fillers and an inorganic substrate (CW) with varying amounts of surface coverage of polystyrene. Glass transition temperatures, thermodynamic parameters, and the London component of the surface free energy (YsL) were deter mined. Values for YsL became constant at higher coverages, allowing the thickness of the interphase to be estimated

CONCENTRATION ISSUES IN THE U.S. BEEF SUBSECTOR

Industrial Organization, Livestock Production/Industries,

Adjusting the Low Energy Threshold for Large Bodies in PET

The performance of a PET scanner on three different phantom sizes was studied as a function of low energy threshold (LET). Phantom cross sections ranged from 20 cm diameter circular to 28 cm x 43 cm oval and LET\u27\u27s ranged from 350 keV to 475 keV, in 25 keV increments. System sensitivity, scatter fraction, and NEC were measured over a wide range of radioactivity levels. Increasing the low energy threshold lowered both sensitivity and scatter fraction. The statistical quality of the raw data was maximized for the 425 keV setting for all three phantoms. System stability and uniformity of response was also studied for 375 keV to 450 keV thresholds, and indicated acceptable performance for this system through 425 keV