Design, Development and Testing of the GMI Launch Locks

Ball Aerospace will deliver the GPM Microwave Imager (GMI), to NASA as one of the 3 instruments to fly on the Global Precipitation Measurement (GPM) mission, for launch in 2013. The radiometer, when deployed, is over 8 feet tall and rotates at 32 revolutions per minute (RPM) can be described as a collection of mechanisms working to achieve its scientific objectives. This collection precisely positions a 1.2 meter reflector to a 48.5 degree off nadir angle while rotating, transferring electrical power and signals to and from the RF receivers, designs two very stable calibration sources, and provides the structural integrity of all the components. There are a total of 7 launch restraints coupling across the moving and stationary elements of the structure,. Getting from design to integration will be the focus of this paper

Spatiotemporal regulation of a Legionella pneumophila T4SS substrate by the metaeffector SidJ

Modulation of host cell function is vital for intracellular pathogens to survive and replicate within host cells. Most commonly, these pathogens utilize specialized secretion systems to inject substrates (also called effector proteins) that function as toxins within host cells. Since it would be detrimental for an intracellular pathogen to immediately kill its host cell, it is essential that secreted toxins be inactivated or degraded after they have served their purpose. The pathogen Legionella pneumophila represents an ideal system to study interactions between toxins as it survives within host cells for approximately a day and its Dot/Icm type IVB secretion system (T4SS) injects a vast number of toxins. Previously we reported that the Dot/Icm substrates SidE, SdeA, SdeB, and SdeC (known as the SidE family of effectors) are secreted into host cells, where they localize to the cytoplasmic face of the Legionella containing vacuole (LCV) in the early stages of infection. SidJ, another effector that is unrelated to the SidE family, is also encoded in the sdeC-sdeA locus. Interestingly, while over-expression of SidE family proteins in a wild type Legionella strain has no effect, we found that their over-expression in a ∆sidJ mutant completely inhibits intracellular growth of the strain. In addition, we found expression of SidE proteins is toxic in both yeast and mammalian HEK293 cells, but this toxicity can be suppressed by co-expression of SidJ, suggesting that SidJ may modulate the function of SidE family proteins. Finally, we were able to demonstrate both in vivo and in vitro that SidJ acts on SidE proteins to mediate their disappearance from the LCV, thereby preventing lethal intoxication of host cells. Based on these findings, we propose that SidJ acts as a metaeffector to control the activity of other Legionella effectors

Some aspects of glutathione and L-arginine/nitric oxide metabolism in the maintenance of platelet function.

Evidence is presented here for the regulation of platelet activation by intra-platelet levels of glutathione (GSH) and L-arginine. Our data is consistent with the intra-platelet GSH ((GSH) \sb{\rm ip}) modulation through the regulation of the thromboxane A\sb2 (TxA\sb2) biosynthesis. The reduction of (GSH) \sb{\rm ip} by 100 $\mu$M 1-chloro-2,4-dinitrobenzene (CDNB) enhanced thrombin-induced platelet aggregation and ADP-induced platelet aggregation was inhibited by the elevation of (GSH) \sb{\rm ip} through a facilitative GSH-specific transport system. Platelet facilitative GSH uptake was subsequently characterized as being Na\sp+-independent, concentration dependent (K\sb{\rm M} and V\sb{\rm max} for GSH uptake in platelet plasma membrane vesicles (PPMV) is $18.2 \pm 3.6\ \mu$M and 178 $\pm$ 27 pmol/min/mg protein, respectively), inhibited by GSH analogs, enhanced by KCl-induced membrane depolarization and sensitive to the intraplatelet thiol redox status since the K\sb{\rm M} and V\sb{\rm max} for GSH uptake in intact platelets changed from 137 $\mu$M and 42.2 pmol/min/10\sp9 platelets, respectively, to 31.7 $\mu$M and 31.3 pmol/min/10\sp9 platelets, respectively, on reducing intra-platelet GSH with 100 $\mu$M CDNB. Glutathione reductase (GR) was found to be inhibited by physiological levels of GSH with species-dependent differences. With respect to varying GSSG, GSH inhibited GR from human platelets in an apparent uncompetitive manner (K\sb{\rm i} = 6.6 mM), while bovine intestinal mucosa and yeast GRs displayed apparent mixed hyperbolic inhibition (K\sb{\rm i} = 2.9 and 2.4 mM, respectively), and the E. coli enzyme exhibited an apparent, competitive inhibition (K\sb{\rm i} = 12.1 mM). In the course of this study it was observed that 1-(4-chlorophenyl)-4,4-dimethyl-5-diethylamino-1-penten-3-one hydrobromide (CDDP) is an alpha class selective glutathione S-transferase (GST) substrate and that certain analogs of CDDP are GST inhibitors with K\sb{\rm i}s ranging from 7.5 to 53.4 $\mu$M. Exogenous L-arginine inhibited ADP-induced platelet aggregation which suggests that platelet-derived NO regulates platelet activation. Platelet L-arginine uptake was via the cationic amino acid transporter, system y\sp+, which appears to be regulated by NO. S-nitrosoglutathione (GSNO) was found to be photolyzed by visible light. The release of NO by GSNO photolysis resulted in an enhanced NO-dependent cytotoxicity towards HL-60 cells. GSNO, or related compounds, may therefore find use as photochemotherapeutic agents.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .S49. Source: Dissertation Abstracts International, Volume: 56-11, Section: B, page: 6097. Adviser: Bulent Mutus. Thesis (Ph.D.)--University of Windsor (Canada), 1995

Use of practice tracks in the medical specialties.

OBJECTIVES: To evaluate the use of practice tracks by each of the 24 medical specialty boards and to compare this with the experience in emergency medicine (EM). METHODS: Scripted telephone surveys were conducted with representatives of each of the specialty boards. RESULTS: Of 24 specialties currently recognized by the American Board of Medical Specialties (ABMS), 14 (58%) reported a history of a practice track. Eight boards reported never having a practice track and 2 were unsure. All practice tracks have been limited in duration, most commonly closing after a specified period. The mean duration of the practice tracks was 9.8 years, the median was 7.5 years, and the range was 3-27 years. The practice track in EM was open for 9 years. CONCLUSIONS: Practice tracks were common in the early years of most specialties and most were limited by duration. The history of the practice track in EM is not dissimilar to those of other specialties

Environmental Differences between Migratory and Resident Ungulates—Predicting Movement Strategies in Rocky Mountain Mule Deer (Odocoileus hemionus) with Remotely Sensed Plant Phenology, Snow, and Land Cover

Migration is a valuable life history strategy for many species because it enables individuals to exploit spatially and temporally variable resources. Globally, the prevalence of species’ migratory behavior is decreasing as individuals forgo migration to remain resident year-round, an effect hypothesized to result from anthropogenic changes to landscape dynamics. Efforts to conserve and restore migrations require an understanding of the ecological characteristics driving the behavioral tradeoff between migration and residence. We identified migratory and resident behaviors of 42 mule deer (Odocoileus hemionus) based on GPS locations and correlated their locations to remotely sensed indicators of forage quality, land cover, snow cover, and human land use. The model classified mule deer seasonal migratory and resident niches with an overall accuracy of 97.8% and cross-validated accuracy of 81.2%. The distance to development was the most important variable in discriminating in which environments these behaviors occur, with resident niche space most often closer to developed areas than migratory niches. Additionally, snow cover in December was important for discriminating summer migratory niches. This approach demonstrates the utility of niche analysis based on remotely sensed environmental datasets and provides empirical evidence of human land use impacts on large-scale wildlife migrations

Louse- and flea-borne rickettsioses: biological and genomic analyses

In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed

Quaternary faulting in the New Madrid seismic zone in southernmost Illinois

U.S. Geological Survey, Department of the Interior, under USGS award number 1434-95-G-2525Ope

Physiological and behavioral response of the Asian shore crab, Hemigrapsus sanguineus, to salinity: implications for estuarine distribution and invasion

The invasive Asian shore crab, Hemigrapsus sanguineus, is ubiquitous in the rocky intertidal zone of the western North Atlantic. A likely contributor to this colonization is that H. sanguineus is able to handle a wide range of salinities, and is thus more likely to spread through a greater geographic area of estuaries. This study investigated the salinity effects on this animal by observing survival across a range of salinities, the maintenance of hemolymph osmolality under different salinities, and behavioral preference for and avoidance of salinities. H. sanguineus showed high survival across a broad range of salinities, had little change in hemolymph osmolality over a short-term salinity shock, and behaviorally distinguished between salinities when presented with a choice, under both acclimation salinities of 5 PSU or 35 PSU. Such results suggest H. sanguineus has a hardiness for the rapid changes in salinity that happen in the intertidal zone, yet is capable of physically moving to a more optimal salinity. This enhances their competitiveness as an invader, particularly surviving lower salinities that present challenges during high-precipitation events in rocky intertidal areas, and partially explains this species’ dominance in this habitat type

Towards a global understanding of the drivers of marine and terrestrial biodiversity

Understanding the distribution of life’s variety has driven naturalists and scientists for centuries, yet this has been constrained both by the available data and the models needed for their analysis. Here we compiled data for over 67,000 marine and terrestrial species and used artificial neural networks to model species richness with the state and variability of climate, productivity, and multiple other environmental variables. We find terrestrial diversity is better predicted by the available environmental drivers than is marine diversity, and that marine diversity can be predicted with a smaller set of variables. Ecological mechanisms such as geographic isolation and structural complexity appear to explain model residuals and also identify regions and processes that deserve further attention at the global scale. Improving estimates of the relationships between the patterns of global biodiversity, and the environmental mechanisms that support them, should help in efforts to mitigate the impacts of climate change and provide guidance for adapting to life in the Anthropocene