Utilizing a constant peak width transform for isothermal gas chromatography.

A computational approach to partially address the general elution problem (GEP), and better visualize, isothermal gas chromatograms is reported. The theoretical computational approach is developed and applied experimentally. We report a high speed temporally increasing boxcar summation (TIBS) transform that, when applied to the raw isothermal GC data, converts the chromatographic data from the initial time domain (in which the peak widths in isothermal GC increase as a function of their retention factors, k), to a data point based domain in which all peaks have the same peak width in terms of number of points in the final data vector, which aides in preprocessing and data analysis, while minimizing data storage size.

Ghrelin secretion is not reduced by increased fat mass during diet-induced obesity.

Ghrelin is a stomach hormone that stimulates growth hormone (GH) secretion, adiposity, and food intake. Gastric ghrelin production and secretion are regulated by caloric intake; ghrelin secretion increases during fasting, decreases with refeeding, and is reduced by diet-induced obesity. The aim of the present study was to test the hypotheses that 1) an increase in body adiposity will play an inhibitory role in the reduction of gastric ghrelin synthesis and secretion during chronic ingestion of a high-fat (HF) diet and 2) chronic ingestion of an HF diet will suppress the rise in circulating ghrelin levels in response to acute fasting.

Relationship perceptions and persistence: do fluctuations in perceived partner commitment undermine dating relationships?

The authors propose specific temporal profiles that reflect certainty versus doubt about where a partner stands with respect to a dating relationship over time. Two multiwave longitudinal studies focused on within-participant changes in perceived partner commitment. Results from multilevel modeling indicate that individuals whose perceptions of partner commitment fluctuate over time were more likely to be in a relationship that eventually ended than were individuals whose perceptions remained relatively steady.