An Expectancy-Value Analysis of Web Gratifications

The present study explored the mechanisms directing Web usage decisions to determine more reliable estimates of the importance of various influences involved. A Web-based survey was administered to respondents who voluntarily participated by responding to a message posted to selected Internet discussion groups. Exploratory factor analysis and covariance structure model were employed to examine the relationships between attitude, expectancies, motivation, intention, and usage regarding the Web. Research evidence spoke strongly against univariate or bivariate motivational schemes. In addition to surveillance and diversion functions that have been found in traditional mass media, the Web also provided two unique qualities, utility and interaction. Approximately one-third of variance in Web usage was explained by expectancy-value judgments or motivations. Other influences, including non-sociological-psychological variables, attributed to Web usage variance remain to be explored. Research findings also indicated that expectancy-value judgments and motives function similarly in determining intention and usage regarding the Web; however, user motives or gratifications appeared to further separate from the general attitude toward the Web. Further improvement in scaling expectancy-value and gratifications items is suggested to attain discriminant and convergent validity. INDEX WORDS: Expectancy-Value, Uses and Gratifications, Web Usag

Effects of oxysterols on acyl-CoA: cholesterol acyltranferase

Two oxysterols, 20(R and S)-20,25-dihydroperoxy-5-cholesten-3[beta]-ol (HPs) isolated from the mixture of cholesterol autoxidation products have been found to reduce effectively cholesteryl ester accumulation in mouse peritoneal macrophages. The effect of HPs was associated with inhibition of cholesterol esterification by suppressing acyl-CoA:cholesterol acyltransferase activity, and by interruption of acetylated low-density-lipoprotein metabolism. The mechanism by which HPs inhibit ACAT activity is investigated in detail in the present study. With reconstituted liposomes, I demonstrated that an increase in cholesterol concentration did not prevent the inhibitory effect of HPs. On the other hand, inactivated ACAT activity was partially restored by treatment with reducing agents, including sodium borohydride, N-methyl-mercaptoacetamide, 2,3-dimercaptopropanol and dithiothreitol. These results suggest that HPs affect the enzyme activity, most likely, through oxidation rather than acting as competitive inhibitors. The reactivities of HPs were studied with model peptides and protein and it was found that the protein sulfhydryl and thioether groups were susceptible to the oxidation by HPs. With specific thiol-modification agent, phenylarsine oxide (PAO), I demonstrated the importance of vicinal sulfhydryl groups for ACAT activity. The facts that phenylarsine oxide-reacted ACAT was insensitive to further inactivation by HP-B and that the same extent of reactivation by 2,3-dimercaptopropanol could be achieved after PAO plus HP-B treatment and after PAO alone suggest that HPs and phenylarsine oxide share common reactive sites. Finally, I proposed a mechanism of two-step modification to explain how HPs inhibit ACAT activity

20-(B)-20,25-dihydroperoxy-3β-hydroxycholest-5-ene and 20-(S)-20,25-dihydroperoxy-3β-hydroxycholest-5-ene

A method is provided for suppressing atherogenesis in which a cholesterol 20-hydroperoxide is administered, which is preferably one or both of the novel compounds: 20(R)-hydroperoxy-25-hydrocholesterol and 29(S)-hydroperoxy-25-hydrocholesterol 20(R)-hydroperoxy-25 hydrocholesterol and 20(S)-hydroperoxy-25-hydrocholesterol are administered. The compositions 20(R)-hydroperoxy-25-hydrocholesterol and 20(S)-hydroperoxy-25-hydrocholesterol are also provided

Effects of oxysterols on acyl-CoA: cholesterol acyltranferase

Two oxysterols, 20(R and S)-20,25-dihydroperoxy-5-cholesten-3[beta]-ol (HPs) isolated from the mixture of cholesterol autoxidation products have been found to reduce effectively cholesteryl ester accumulation in mouse peritoneal macrophages. The effect of HPs was associated with inhibition of cholesterol esterification by suppressing acyl-CoA:cholesterol acyltransferase activity, and by interruption of acetylated low-density-lipoprotein metabolism. The mechanism by which HPs inhibit ACAT activity is investigated in detail in the present study. With reconstituted liposomes, I demonstrated that an increase in cholesterol concentration did not prevent the inhibitory effect of HPs. On the other hand, inactivated ACAT activity was partially restored by treatment with reducing agents, including sodium borohydride, N-methyl-mercaptoacetamide, 2,3-dimercaptopropanol and dithiothreitol. These results suggest that HPs affect the enzyme activity, most likely, through oxidation rather than acting as competitive inhibitors. The reactivities of HPs were studied with model peptides and protein and it was found that the protein sulfhydryl and thioether groups were susceptible to the oxidation by HPs. With specific thiol-modification agent, phenylarsine oxide (PAO), I demonstrated the importance of vicinal sulfhydryl groups for ACAT activity. The facts that phenylarsine oxide-reacted ACAT was insensitive to further inactivation by HP-B and that the same extent of reactivation by 2,3-dimercaptopropanol could be achieved after PAO plus HP-B treatment and after PAO alone suggest that HPs and phenylarsine oxide share common reactive sites. Finally, I proposed a mechanism of two-step modification to explain how HPs inhibit ACAT activity.</p

20-(B)-20,25-dihydroperoxy-3β-hydroxycholest-5-ene and 20-(S)-20,25-dihydroperoxy-3β-hydroxycholest-5-ene

A method is provided for suppressing atherogenesis in which a cholesterol 20-hydroperoxide is administered, which is preferably one or both of the novel compounds: 20(R)-hydroperoxy-25-hydrocholesterol and 29(S)-hydroperoxy-25-hydrocholesterol 20(R)-hydroperoxy-25 hydrocholesterol and 20(S)-hydroperoxy-25-hydrocholesterol are administered. The compositions 20(R)-hydroperoxy-25-hydrocholesterol and 20(S)-hydroperoxy-25-hydrocholesterol are also provided.</p

Affects And Post-Adoption Behaviors Of Blog Users

Positive and negative word-of-mouth (WOM) have yet well-understood in social media like blogs. These affective-driven WOM and cognitive-driven acceptance decision are important to e-services success. In this study, we incorporate two main streams of IS research: 1)the quality of the systems in determining systems success and 2) the effects of online incidents including online waiting, interruptions, and service failures on consumer behaviors, to understand these affective and cognitive-driven behaviors. We bridge the two streams of research and explain blog usage from the perspectives of affective events theory and social exchange factors. The research model posits that blog usage behaviors are determined by perceived site quality and cognitive appraisal of incidents handling (CAIH) and satisfaction mediated the effects of positive and negative affects to post-adoption behaviors. Results of partial least squares analysis with 467 responses from an online survey indicate that all measures have acceptable psychometric properties and confirmatory factor analysis attests the dimensionality of constructs. Structural equation analysis provides evidence for the structure relationships of the integrated model