60 research outputs found

    A Historical Investigation into Item Formats of ACS Exams and Their Relationships to Science Practices

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    The release of the NRC Framework for K-12 Science Education and the Next Generation Science Standards has important implications for classroom teaching and assessment. Of particular interest is the implementation of science practices in the chemistry classroom, and the definitions established by the NRC makes these objectives much more tangible. However, this still may leave some wondering about how to begin making these changes. Mid-twentieth century chemical educators and pioneers of the first ACS exams advocated for testing science thinking and skills as early as the 1930s, and this necessitates a discussion about how early ACS exams measured these attributes. More recent debates have seen arguments that multiple-choice questions cannot measure high levels of cognitive ability in chemistry, which leaves questions about how ACS exams or instructors who write tests for large scale classrooms might try to measure science practices. The possibility that an analysis of the item formats used on ACS exams from 1934 to 1970 would help inform the creation of improved item types in testing today is investigated and presented here.Reprinted (adapted) with permission from J. Chem. Educ., 2015, 92 (11), pp 1798–1806. Copyright 2015 American Chemical Society.</p

    PKA and CaMKII mediate PI3K activation in bovine sperm by inhibition of the PKC/PP1 cascade

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    To enable fertilization, spermatozoa must undergo several biochemical processes in the female reproductive tract, collectively called capacitation. These processes involve protein kinase A (PKA)-dependent protein tyrosine phosphorylation including phosphatidylinositol-3-kinase (PI3K). It is not known how PKA, a serine/threonine (S/T) kinase, mediates tyrosine phosphorylation of proteins. We recently showed that inhibition of S/T phosphatase 1 (PP1) causes a significant increase in phospho-PI3K. In this study, we propose a mechanism by which PKA and PP1 mediate an increase in PI3K tyrosine phosphorylation and implicate calmodulin-dependent kinase II (CaMKII) in this process. Inhibition of sperm PP1 or PKC, stimulated CaMKII phosphorylation/activation, and inhibition of PKC enhanced PP1 phosphorylation/inactivation. Inhibition of CaMKII, using KN-93, caused significant reduction in phospho-PP1, indicating its activation. Moreover, KN-93 prevented the dephosphorylation/inactivation of PKC. We therefore suggest that CaMKII inhibits PKC, leading to PP1 inhibition and the reciprocal auto-activation of CaMKII. Thus, CaMKII can regulate its own activation by inhibiting the PKC/PP1 cascade. Inhibition of Src family kinases (SFK) caused significant inhibition of CaMKII and PP1 phosphorylation, suggesting that SFK activity results in PP1 inhibition and CaMKII activation. Activation of sperm PKA by 8Br-cAMP revealed an increase in phospho-CaMKII, which was inhibited by PKA inhibitor. Tyrosine phosphorylation of PI3K was stimulated by 8Br-cAMP and by PKC or PP1 inhibition and was abrogated by CaMKII inhibition. Furthermore, phosphorylation/activation of the tyrosine kinase Pyk2 was enhanced by PP1 inhibition, and this activation is blocked by CaMKII inhibition. Thus, PKA activates Src, which inhibits PP1, leading to CaMKII and Pyk2 activation, resulting in PI3K tyrosine phosphorylation/activation.</jats:p

    Fear appeals in anti-smoking advertising : how important is self-efficacy?

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Marketing Management on 11 October 2012, available online at: http://www.tandfonline.com/doi/abs/10.1080/0267257X.2012.715092Fear appeals are frequently used in anti-smoking advertising. The evidence on the effectiveness of fear appeals is mixed, and in some studies strong fear appeals have been found to reinforce the undesirable behaviour. Individual self-efficacy may play a role in moderating the effects of fear appeals. In advertising contexts where the intention was to encourage socially desirable behaviours, it has been shown that greater self-efficacy is associated with a more positive response to fear appeals. Similarly, in such contexts, the perceived ethicality of a fear-appeal advertisement appears to be positively related to self-efficacy. The purpose of this article is to examine the relationship between self-efficacy, perceived ethicality, and the impact of advertising on behavioural intentions in a context where the aim is to discourage undesirable behaviour, namely anti-smoking advertising. Questionnaire data were gathered from 434 respondents in London, England. Respondents with higher reported self-efficacy were found to have more favourable views of the ethicality of fear-appeal advertising, more positive attitudes towards the advertising, and stronger intentions to quit smoking. It is recommended that when using fear appeals in advertising to discourage undesirable behaviour, advertisers should incorporate messages designed to enhance self-efficacy.Peer reviewe
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