Effect of Photoperiod and Acute Stress on Facilitative Glucose Transporter GLUT3 in Siberian Hamsters (Phodopus sungorus)

Metabolic activity in mammalian brains is fundamentally dependent upon glucose utilization. Transport of glucose from the blood to the brain requires mediation by a family of integral membrane proteins known as facilitative glucose transporter proteins (GLUTs). The GLUT3 isoform is solely responsible for facilitating glucose transport in the neurons of mammalian brains. Studies show that age-related brain dysfunction and disease, as well as reductions in learning and memory correlate with decreased GLUT3 expression. Winter is a particularly difficult time to reproduce and survive because of the energy bottleneck caused by the coincidence of low ambient temperatures with reduced food availability. Individuals cope with this seasonal energetic bottleneck by engaging tradeoffs among expensive physiological processes through development of specific adaptations including adjustments in metabolic rate, body mass, reproduction, and immune function. Non-tropical animals determine time-of-year by monitoring photoperiod (day length) in order to evoke the appropriate suite of adaptations. However, such metabolic trade-offs can be challenged by stressors. To test the combined effects of acute stress and photoperiod on GLUT3 expression, male adult Phodopus sungorus were housed in either long (LD – 16 h of light/day) or short (SD – 8 h of light/day) photoperiods for 14 weeks. After 14 weeks, half of the animals from each photoperiod were subjected to 4 h of restraint stress immediately prior to brain collection. Brain tissue from each animal was excised and the hippocampus of each sample was used in GLUT3 gene expression analysis. The findings of this study demonstrate that photoperiod and acute stress do not impact the facilitative glucose transporter GLUT3 at the RNA expression level. Further research needs to be conducted in order to determine the precise mechanism which regulates the expression of the GLUT3 transporter in neurons of the hippocampus.Student Achievement in Research and Scholarship (STARS) GrantNo embarg

Configurational temperatures and interactions in charge-stabilized colloid

We demonstrate that the configurational temperature formalism can be derived from the classical hypervirial theorem, and introduce a hierarchy of hyperconfigurational temperature definitions, which are particularly well suited for experimental studies. We then use these analytical tools to probe the electrostatic interactions in monolayers of charge-stabilized colloidal spheres confined by parallel glass surfaces. The configurational and hyperconfigurational temperatures, together with a novel thermodynamic sum rule, provide previously lacking self-consistency tests for interaction measurements based on digital video microscopy, and thereby cast new light on controversial reports of confinement-induced like-charge attractions. We further introduce a new method for measuring the pair potential directly that uses consistency of the configurational and hyperconfigurational temperatures as a set of constraints for a model-free search.Comment: 15 pages, 12 figures, submitted to J. Chem. Phy

Guidance, flight mechanics and trajectory optimization. Volume 11 - Guidance equations for orbital operations

Mathematical formulation of guidance equations and solutions for orbital space mission

Testing the Hypothesis of Young Martian Volcanism: Studies of the Tharsis Volcanoes and Adjacent Lava Plains

We experienced much success in reaching our stated goals in our original MDAP proposal. Our work made substantial contributions towards an integrated understanding of the counting and calibration of crater data on Mars, and changing nature of the Martian surface influenced by craters, water, and wind, and their general relationship to Martian geothermal history. We accomplished this while being to responsive to the rapid changes in the field brought about by several key NASA missions that returned data during the life of the grant. Our integrated effort included three stages: The first major area of research (Crater Count Research) was conducted by Jennifer Grier (P.I.), Lazslo Keszthelyi (Collaborator), William Hartmann (Collaborator), with assistance from Dan Berman (Graduate student) and concerned the mapping and the collection of crater count data on various Martian terrains. The second major area of study (Absolute Age Calibration) was conducted by William Bottke (Co-I) at SWRI, and concerned constraining the nature of the Moon and Mars impactor populations to create better absolute age calibrations for counted areas. The third major area of study was the integration and leverage of this effort with ongoing related Mars crater work at PSI (Integrated and Continuing Studies - Older Volcanoes), headed by David Crown (PSI Scientist), assisted by Les Bleamaster (PSI Scientist) and Dan Berman (Graduate Student)

Determination of transition frequencies in a single 138^{138}Ba+^{+} ion

Transition frequencies between low-lying energy levels in a single trapped $^{138}$Ba$^{+}$ ion have been measured with laser spectroscopy referenced to an optical frequency comb. By extracting the frequencies of one-photon and two-photon components of the line shape using an eight-level optical Bloch model, we achieved 0.1 MHz accuracy for the 5d $^{2}$D$_{3/2}$ - 6p $^{2}$P$_{1/2}$ and 6s $^{2}$S$_{1/2}$ - 5d $^{2}$D$_{3/2}$ transition frequencies, and 0.2 MHz for the 6s $^{2}$S$_{1/2}$ - 6p $^{2}$P$_{1/2}$ transition frequency.Comment: 5 pages, 7 figures, submitted to Phys. Rev.

Management of Gunshot Wounds

With the increasing number of hunting accidents and gunshot wounds seen by the practitioner it is important to know the result of wounds created by different types of firearms. This information is of value to both the small and large animal practitioner. Most of the literature available comes from publications of human war wounds in Vietnam, the Korean conflict, and World War II. The wound will vary as to the type of firearm used (high velocity vs low velocity), the trajectory angulation, and distance between the firearm and target. The type of ammunition used, its mass, and velocity are also factors that should be considered. The specific gravity of the tissues involved may also influence the extent of the injury. There is no one treatment regime in the management of these wounds, and each case should be treated as a separate entity