Induction of ovulation in proestrous ewes: Identification of the ovulatory follicle and functional status of the corpus luteum

Ewes were treated with a luteolytic agent on Day 14 of the estrous cycle. Their largest follicle was identified 30 hr later. Thirty-six hr post-treatment, ewes received an injection of an analog of luteinizing hormone-releasing hormone (LHRHa). The peak in the induced surge of LH occurred 2 to 4 hr after injection of LHRHa. Ovulation occurred from the largest follicle approximately 24 hr following administration of LHRHa. During the subsequent luteal phase, serum concentrations of progesterone were normal. The treatment regimen described is well-suited for collection of follicles at precisely-timed periovulatory intervals. Perhaps information gained by using this model will be useful in ultimately understanding the follicular events associated with ovulation and function of the corpus luteum.     

The effect of histone gene deletions on chromatin structure in Saccharomyces cerevisiae

As a way of studying nucleosome assembly and maintenance in Saccharomyces cerevisiae, mutants bearing deletions or duplications of the genes encoding histones H2A and H2B were analyzed. Previous genetic analysis had shown that only one of these mutants exhibited dramatic and pleiotropic phenotypes. This mutant was also the only one that contained disrupted chromatin, suggesting that the original phenotypes were attributable to alterations in chromosome structure. The chromatin disruption in the mutant, however, did not extend over the entire genome, but rather was localized to specific regions. Thus, while the arrangement of nucleosomes over the HIS4 and GAL1 genes, the telomeres, and the long terminal repeats (delta sequences) of Ty retrotransposons appeared essentially normal, nucleosomes over the CYH2 and UBI4 genes and the centromere of chromosome III were dramatically disrupted. The observation that the mutant exhibited localized chromatin disruptions implies that the assembly or maintenance of nucleosomes differs over different parts of the yeast genome.     

Polar motion from laser tracking of artificial satellites

Measurements of the range to the Beacon Explorer C spacecraft from a single laser tracking system at Goddard Space Flight Center have been used to determine the change in latitude of the station arising from polar motion. A precision of 0.03 arc second was obtained for the latitude during a 5-month period in 1970.     

Electrical energy storage for the grid: a battery of choices

The increasing interest in energy storage for the grid can be attributed to multiple factors, including the capital costs of managing peak demands, the investments needed for grid reliability, and the integration of renewable energy sources. Although existing energy storage is dominated by pumped hydroelectric, there is the recognition that battery systems can offer a number of high-value opportunities, provided that lower costs can be obtained. The battery systems reviewed here include sodium-sulfur batteries that are commercially available for grid applications, redox-flow batteries that offer low cost, and lithium-ion batteries whose development for commercial electronics and electric vehicles is being applied to grid storage.     

Spending money on others promotes happiness

Although much research has examined the effect of income on happiness, we suggest that how people spend their money may be at least as important as how much money they earn. Specifically, we hypothesized that spending money on other people may have a more positive impact on happiness than spending money on oneself. Providing converging evidence for this hypothesis, we found that spending more of one's income on others predicted greater happiness both cross-sectionally (in a nationally representative survey study) and longitudinally (in a field study of windfall spending). Finally, participants who were randomly assigned to spend money on others experienced greater happiness than those assigned to spend money on themselves.     

Heat Transfer in Magma in situ

Heat transfer rates in a basaltic magma were measured under typical magma chamber conditions and a numerical model of the experiment was used to estimate magma viscosity. The results are of value for assessing methods of thermal energy extraction from magma bodies in the upper crust as well as for modeling the evolutionary track of these systems.