University of Akron

About: University of Akron is a education organization based out in Akron, Ohio, United States. It is known for research contribution in the topics: Polymer & Polymerization. The organization has 17401 authors who have published 29127 publications receiving 702386 citations. The organization is also known as: The University of Akron.

Dissociation of the peptide bond in protonated peptides

Abstract: The dissociation of the amide (peptide) bond in protonated peptides, [M + H]+, is discussed in terms of the structures and energetics of the resulting N-terminal bn and C-terminal yn sequence ions. The combined data provide strong evidence that dissociation proceeds with no reverse barriers through interconverting proton-bound complexes between the segments emerging upon cleavage of the protonated peptide bond. These complexes contain the C-terminal part as a smaller linear peptide (amino acid if one residue) and the N-terminal part either as an oxazolone or a cyclic peptide (cyclic amide if one residue). Owing to the higher thermodynamic stability but substantially lower gas-phase basicity of cyclic peptides vs isomeric oxazolones, the N-terminus is cleaved as a protonated oxazolone when ionic (bn series) but as a cyclic peptide when neutral (accompanying the C-terminal yn series). It is demonstrated that free energy correlations can be used to derive thermochemical data about sequence ions. In this context, the dependence of the logarithm of the abundance ratio log[y1/b2], from protonated GGX (G, glycine; X, varying amino acid) on the gas-phase basicity of X is used to obtain a first experimental estimate of the gas-phase basicity of the simplest b-type oxazolone, viz. 2-aminomethyl-5-oxazolone (b2 ion with two glycyl residues). Copyright © 2000 John Wiley & Sons, Ltd.

Awareness of Text Structure: Effects on Recall*

Abstract: Research in second language reading has shown relationships among reading comprehension, reading strategies, and metacognitive awareness of reading strategies (Block, 1986; Barnett, 1988; Carrell, 1989, Carrell, Pharis, & Liberto, 1989). Moreover, research with native speakers of English has shown differences in speakers’ awareness of particular expository text structures (comparison/contrast, description, causation, and problem/solution) and their recall of texts written in those structures (Richgels, McGee, Lomax, & Sheard, 1987). Whereas previous research in ESL has examined the effects of differences in rhetorical structure on learners’ recall of English narrative (Carrell, 1984a) and expository text (Carrell, 1984b, 1985), this ESL research has not investigated differences between learners’ awareness of particular text structures and their recall of texts written in those structures. Nor has the ESL research contrasted different measures of structure awareness. The study reported in this paper was designed to investigate these relationships in EFL/ESL reading. Forty-five high-intermediate proficiency ESL students produced written recalls of both comparison/contrast and collection of description texts. In addition, two different measures of awareness were included: (1)use of organization in written recall, and (2) recognition of organization in response to a probe question. Results showed that there were no differences in levels of awareness, regardless of how it was measured, due to differences in text structure, nor were there any differences in the quantity of information recalled between text structures. However, there were differences in the quality of information recalled as a function of text structure. Finally, in terms of relationships between awareness and recall, subjects who used the structure of the reading passages to organize written recalls showed superior recall both quantitatively and qualitatively.

Adaptation to multiple sclerosis: the role of social support, functional disability, and perceived uncertainty.

Abstract: This study was designed to test a path model depicting the relationships among social support, functional disability, perceived uncertainty, and psychosocial adaptation in 38 men and 80 women with multiple sclerosis, a chronic, unpredictable disease. Results from the regression analyses indicated that 35% of the variance in depression and 33% of the variance in purpose-in-life, respectively, were explained by age, sex, social status, and the perceived supportiveness and unsupportiveness of social network interactions. The path analyses showed that the perceived supportiveness of interactions was directly related to purpose-in-life but not to depression; both the direct path between the perceived unsupportiveness of interactions and adaptation and the indirect one through perceived uncertainty were related to depression and to purpose-in-life; and functional disability had a direct effect on adaptation, but the indirect path through perceived uncertainty was not corroborated.

The Consequences of Caring: Exploring the Links Between Women's Job and Family Emotion Work

Abstract: Sociologists of emotion have examined the ways that workers are required to manage their emotions on the job, while studies of family emotion work reveal the effort involved in providing emotional ...