The Effects of X-rays and Beta Rays (Tritium) on the Growth of \u3cem\u3eRickettsia mooseri\u3c/em\u3e and \u3cem\u3eRickettsia akari\u3c/em\u3e in Embryonate Eggs

The growth of Rickettsia mooseri was accelerated and quantitatively increased in embryonate eggs containing tritium oxide at levels of 180, 90, and 45 mc./egg during the growth period. The eggs of a group containing 22.5 mc./egg showed only a slight increase in the rate of growth of organisms; the infections in the eggs of a group given 11.2 mc./egg did not differ significantly from those of the control group. On the other hand, growth of R. akari was inhibited in embryonate eggs containing tritium oxide at levels of 180, 90, and 45 mc./egg, and partially inhibited in groups containing 22.5 and 11.2 mc./egg. The patterns of growth of R. mooseri and of R. akari exposed to tritium oxide for 6 hours prior to inoculation into embryonate eggs did not differ significantly from that of the control group

Size Dependence in Non-sperm Ejaculate Production is Reflected in Daily Energy Expenditure and Resting Metabolic Rate

The non-sperm components of an ejaculate, such as copulatory plugs, can be essential to male reproductive success. But the costs of these ejaculate components are often considered trivial. In polyandrous species, males are predicted to increase energy allocation to the production of non-sperm components, but this allocation is often condition dependent and the energetic costs of their production have never been quantified. Red-sided garter snakes (Thamnophis sirtalis parietalis) are an excellent model with which to quantify the energetic costs of non-sperm components of the ejaculate as they exhibit a dissociated reproductive pattern in which sperm production is temporally disjunct from copulatory plug production, mating and plug deposition. We estimated the daily energy expenditure and resting metabolic rate of males after courtship and mating, and used bomb calorimetry to estimate the energy content of copulatory plugs. We found that both daily energy expenditure and resting metabolic rate were significantly higher in small mating males than in courting males, and a single copulatory plug without sperm constitutes 5–18% of daily energy expenditure. To our knowledge, this is the first study to quantify the energetic expense of size-dependent ejaculate strategies in any species

The direct determination of the effect of pressure on enthalpy of a mixture of methane and propane

A new throttling flow calorimeter has been incorporated into the recycle facility of the Thermal Properties Laboratory. Energy is added to the expanding gas while it flows through a stainless steel capillary tubing from an insulated resistance wire located inside the entire length of the capillary. The calorimeter is designed to operate at pressures up to 2,000 lb./sq.in.abs. in the temperature range from −240 to +250°F. Data on the isothermal effect of pressure on enthalpy for a mixture containing 5 mole % propane in methane are presented and compared with data from the literature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37350/1/690150125_ftp.pd

Experimental determinations of several thermal properties of a mixture containing 51 mole percent Propane in Methane

Results of calorimetric determinations are reported for a mixture containing approximately 51 mole % propane in methane. Measurements were made with both isobaric and throttling flow calorimeters in the liquid, critical, gaseous, and two-phase regions in the temperature range from −250° to +300°F. at pressures of between 100 and 2,000 lb./sq. in. abs. Tables of experimental values of heat capacity, Joule-Thomson coefficient, and isothermal throttling coefficient are presented, and the values of C p and φ are summarized on parametric plots. Experimental values of enthalpy differences within the two-phase region determined under both isobaric and isothermal conditions are also reported together with the experimentally determined phase boundary data. A skeleton enthalpy table is presented which is based almost entirely on experimental data obtained in this investigation. Comparisons are made with other published calorimetric data and with calculations based on PVT data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37356/1/690160528_ftp.pd

The Energy-Water Nexus

Speakers for the 2013 Symposium included Professor Joshua P. Fershee of West Virginia University; Professor Gabriel E. Eckstein of Texas A&M University School of Law; Professor Keith B. Hall, Louisiana State University; Professor Donald T. Hornstein from the University of North Carolina; Professor Shi-Ling Hsu, Florida State University; Professor Rhett Larson, of the University of Oklahoma; Professor Amanda Leiter, American University; Professor Uma Outka, University of Kansas; Professor Justin Pidot, of the University of Denver; Professor Melissa Powers from Lewis & Clark College; Mr. Jefferson D. Reynolds, Virginia Department of Environmental Quality; Dr. Benjamin K. Sovacool & Mr. Alex Gilbert from Vermont Law School; and Ms. Andrea Wortzel, of Troutman Sanders LLP

Small-molecule inhibition of a depalmitoylase enhances Toxoplasma host-cell invasion.

Although there have been numerous advances in our understanding of how apicomplexan parasites such as Toxoplasma gondii enter host cells, many of the signaling pathways and enzymes involved in the organization of invasion mediators remain poorly defined. We recently performed a forward chemical-genetic screen in T. gondii and identified compounds that markedly enhanced infectivity. Although molecular dissection of invasion has benefited from the use of small-molecule inhibitors, the mechanisms underlying induction of invasion by small-molecule enhancers have never been described. Here we identify the Toxoplasma ortholog of human APT1, palmitoyl protein thioesterase-1 (TgPPT1), as the target of one class of small-molecule enhancers. Inhibition of this uncharacterized thioesterase triggered secretion of invasion-associated organelles, increased motility and enhanced the invasive capacity of tachyzoites. We demonstrate that TgPPT1 is a bona fide depalmitoylase, thereby establishing an important role for dynamic and reversible palmitoylation in host-cell invasion by T. gondii