Effect of the general anesthetic halothane on the activity of the transverse tubule Ca(2+)-activated K+ channel

The effect of cycloheximide on increased splanchnic prostacyclin release following acute hemorrhage was studied in the rat. Male Sprague-Dawley rats were anesthetized and subjected to acute hemorrhage to 30 mm Hg for 30 min (shock) or sham shock. The superior mesenteric artery was cannulated and removed with its end organ intestine (SV + SI preparation) and perfused in vitro with oxygenated Krebs-Henseleit buffer. Cycloheximide was infused in half of the sham and acute hemorrhage SV + SI preparations at 50 micrograms/ml. Venous effluent from all groups were analyzed for prostanoid release by radioimmunoassay. The SV + SI released 10-fold more 6-keto-prostaglandin (PG) F1 alpha than PGE2 and thromboxane. Acute hemorrhage increased SV + SI release of 6-keto-PGF1 alpha 3-fold compared to sham. Cycloheximide abolished the increased 6-keto-PGF1 alpha following acute hemorrhage but not the basal release in the sham group. Indomethacin decreased PG synthesis in all groups by 90%. Sham PG release was dependent on a stable pool of cyclooxygenase with a long half-life and was not affected by cycloheximide treatment. Acute hemorrhage stimulated a rapid induction of enzymes (cyclooxygenase, prostacyclin synthase) responsible for prostacyclin synthesis and release which were dependent on de novo protein synthesis.     

Level and instability of day-to-day psychological well-being and risk for depression

Human alpha1-acid glycoprotein (AAG) is a mixture of at least two genetic variants: the A variant and the F1 and/or S variant or variants, which are encoded by two different genes. In a continuation of previous studies indicating specific drug transport roles for each AAG variant according to its separate genetic origin, this work was designed to (1) determine the affinities of the two main gene products of AAG (i.e., the A variant and a mixture of the F1 and S variants) for 35 chemically diverse drugs and (2) to obtain meaningful 3D-QSARs for each binding site. Affinities were obtained by displacement experiments, leading to qualitative indications about binding site characteristics. In particular, drugs binding selectively to the A variant displayed some common structural features, but this was not seen for the F1*S variants. Three-dimensional QSAR analyses using the CoMFA method yielded a steric model for binding to the A variant, from which a simplified haptophoric model was derived. In contrast, no statistically sound model was found for the F1*S variants, possibly due (among other reasons) to an insufficient number of high affinity ligands in the set.     

The electret effect in cellulose acetate reverse osmosis membranes

The electret potentials developed by reverse osmosis electret membranes help control the undesirable deposition of charged colloidal particles on the membrane surfaces during membrane desalination. These antifouling electret membranes should help prevent the costly flux declines normally associated with deposition of colloidal iron oxides on the reverse osmosis membrane surfaces. Homocharge and heterocharge behavior of cellulose acetate membrane electrets have been studied. Asymmetric reverse osmosis membranes and dense membrane films were studied. The homocharge and heterocharge of cellulose acetate reverse osmosis electret membranes have been explained.     

Moving toward more perfect unions: Daily and long-term consequences of approach and avoidance goals in romantic relationships.

In 2 daily experience studies and a laboratory study, the authors test predictions from approach-avoidance motivational theory to understand how dating couples can maintain feelings of relationship satisfaction in their daily lives and over the course of time. Approach goals were associated with increased relationship satisfaction on a daily basis and over time, particularly when both partners were high in approach goals. Avoidance goals were associated with decreases in relationship satisfaction over time, and people were particularly dissatisfied when they were involved with a partner with high avoidance goals. People high in approach goals and their partners were rated as relatively more satisfied and responsive to a partner's needs by outside observers in the lab, whereas people with high avoidance goals and their partners were rated as less satisfied and responsive. Positive emotions mediated the link between approach goals and daily satisfaction in both studies, and responsiveness to the partner's needs was an additional behavioral mechanism in Study 2. Implications of these findings for approach-avoidance motivational theory and for the maintenance of satisfying relationships over time are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Late positive potential to appetitive stimuli and local attentional bias.

Predicated on the idea that positive affects high in approach motivation are crucial in goal-directed behaviors, research has found that these positive affects cause narrowed attention. The present research was designed to investigate a possible neurophysiological underpinning of this effect. Previous research has suggested that the late positive potential (LPP) of the event-related brain potential is increased by emotionally arousing stimuli because of the attention-grabbing nature of such stimuli. Other research has suggested that left prefrontal cortical regions are associated with narrowed attention and approach-motivated affect. Integrating these two lines of evidence, the present research examined LPPs to appetitive versus neutral pictures and assessed the relationship of these LPPs to local versus global attentional bias following the picture primes. Results revealed that appetitive in comparison with neutral pictures evoked larger LPP amplitudes bilaterally over central and parietal regions and asymmetrically over frontal regions. Moreover, these LPP amplitudes to appetitive pictures predicted greater locally biased attention caused by the appetitive pictures. These results provide the first evidence that LPPs are associated with the local attentional bias induced by appetitive motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maintaining centralised application systems: a cross-country,cross-sector,cross-platform comparison

Past studies of software maintenance issues have largely concentrated on the average North American firm. While they have made a substantial contribution to good information system management practice, it is believed that further segmentation of sample data and cross-country comparisons will help to identify patterns of behaviour more akin to many less average organizations in North America and elsewhere. This paper compares the Singapore maintenance scene with the reported North American experience. Comparisons are also made between: Government organizations, Singapore corporations and multinational corporations (MNCs); mainframe and minicomputer installations; and fourth-generation language (4GL) and non-4GL computer installations. Study findings, while in many cases were similar to earlier US studies, do show the importance of Singapore's young application portfolio, the widespread usage of 4GLs and the severe maintenance personnel problems.     

Maintaining sexual desire in intimate relationships: The importance of approach goals.

Three studies tested whether adopting strong (relative to weak) approach goals in relationships (i.e., goals focused on the pursuit of positive experiences in one's relationship such as fun, growth, and development) predict greater sexual desire. Study 1 was a 6-month longitudinal study with biweekly assessments of sexual desire. Studies 2 and 3 were 2-week daily experience studies with daily assessments of sexual desire. Results showed that approach relationship goals buffered against declines in sexual desire over time and predicted elevated sexual desire during daily sexual interactions. Approach sexual goals mediated the association between approach relationship goals and daily sexual desire. Individuals with strong approach goals experienced even greater desire on days with positive relationship events and experienced less of a decrease in desire on days with negative relationships events than individuals who were low in approach goals. In two of the three studies, the association between approach relationship goals and sexual desire was stronger for women than for men. Implications of these findings for maintaining sexual desire in long-term relationships are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)