Duquesne University

About: Duquesne University is a education organization based out in Pittsburgh, Pennsylvania, United States. It is known for research contribution in the topics: Population & Health care. The organization has 3615 authors who have published 7169 publications receiving 180066 citations. The organization is also known as: Duquesne University of the Holy Spirit.

The Relationship between Alumni and University: Toward a Theory of Discretionary Collaborative Behavior

Abstract: This paper explores the long term relationship between alumni and universities. While alumni are not usually thought of as customers, the university’s continued dependence on them for financial and other resources makes them a useful relationship marketing example. This study examines discretionary collaborative behavior (DCB) performed by alumni and factors that lead to that behavior. DCBs are behaviors performed by a customer to help a vendor, company, or institution, which contribute to the effective functioning of the relationship, which are outside formal contractual obligations, and are performed. without expectation of direct reward. Findings show antecedents of DCBs are: satisfaction with performance, relational bonds, and individual attributes.

Design, synthesis, and X-ray crystal structure of a potent dual inhibitor of thymidylate synthase and dihydrofolate reductase as an antitumor agent.

Abstract: A novel N-?2-amino-4-methyl[(pyrrolo[2, 3-d]pyrimidin-5-yl)ethyl]benzoyl?-L-glutamic acid (3a) was designed and synthesized as a potent dual inhibitor of thymidylate synthase (TS) and dihydrofolate reductase (DHFR) and as an antitumor agent. Compound 3b, the N7-benzylated analogue of 3a, was also synthesized as an antitumor agent. The synthesis of 3a was accomplished via a 12-step sequence which involved the synthesis of 2-amino-4-methylpyrrolo[2,3-d]pyrimidine (10) in 5 steps from 2-acetylbutyrolactone. Protection of the 2-amino group of 10 and regioselective iodination at the 5-position followed by palladium-catalyzed coupling afforded intermediate 14 which was converted to 3a by reduction and saponification. Similar synthetic methodology was used for 3b. X-ray crystal structure of the ternary complex of 3a, DHFR, and NADPH showed that the pyrrolo[2, 3-d]pyrimidine ring binds in a "2,4-diamino mode" in which the pyrrole nitrogen mimics the 4-amino moiety of 2,4-diaminopyrimidines. This is the first example of a classical pyrrolo[2,3-d]pyrimidine antifolate shown to have this alternate mode of binding to DHFR. Compounds 3a and 3b were more inhibitory than LY231514 against TS from Lactobacillus casei and Escherichia coli. Analogue 3a was also more inhibitory against DHFR from human, Toxoplasma gondii, and Pneumocystis carinii. Evaluation of 3a against methotrexate (MTX)-resistant cell lines with defined mechanisms indicated that cross-resistance of 3a was much lower than that of MTX. Metabolite protection studies and folylpoly-gamma-glutamate synthetase studies suggest that the antitumor activity of 3a against the growth of tumor cells in culture is a result of dual inhibition of TS and DHFR. Compound 3a inhibited the growth of CCRF-CEM and FaDu cells in culture at ED(50) values of 12.5 and 7.0 nM, respectively, and was more active against FaDu cells than MTX. In contrast, compound 3b was inactive against both cell lines. Compound 3a was evaluated in the National Cancer Institute in vitro preclinical antitumor screening program and afforded IG(50) values in the nanomolar range against a number of tumor cell lines.

The Temporal-Interactive Influence of Reading Achievement and Reading Attitude.

Abstract: Although the relationship between attitudes toward reading and reading achievement has been well documented, the causal relationship between these constructs remains unclear.Using longitudinal covariance structure modeling, this study tested the hypothesis that 3 reading-related constructs in the primary grades (2nd-3rd grade) – reading attitude, behavior, and achievement – would predict reading achievement in the 7th grade. Results showed that primary attitude was not correlated with primary achievement yet both had causal paths to 7th-grade achievement, described as a “temporal-interaction” model. The resulting model suggests that while reading attitude and achievement may appear unrelated at the early stages of reading they become more closely linked over time, developing into important causal determinants of reading achievement by early adolescence.

Performance of blind and sighted humans on a tactile grating detection task

Abstract: We compared the abilities of blind and sighted humans to distinguish grooved from smooth surfaces pressed against the stationary index fingertip. Ranging in age from 20 to 72 years, 37 blind and 47 sighted subjects participated in an automated two-alternative forced-choice tactile grating detection task. The tactile acuity of blind and sighted subjects declined with age at equivalent rates (0.011-mm threshold increase per year), but the blind subjects were able to perceive significantly thinner grooves than were their sighted peers (the average difference between blind and sighted subjects of the same age and gender was 0.267 mm). The blind Braille readers performed no better than the blind nonreaders, and the congenitally blind subjects performed equivalently to those with adult-onset blindness. The superior tactile acuity of blind persons may result from the involvement of normally visually responsive cerebrocortical areas in tactile processing, as shown by functional-imaging studies.

Molecular recognition and binding of thermal hysteresis proteins to ice.

Abstract: Molecular recognition and binding are two very important processes in virtually all biological and chemical processes. An extremely interesting system involving recognition and binding is that of thermal hysteresis proteins at the ice-water interface. These proteins are of great scientific interest because of their antifreeze activity. Certain fish, insects and plants living in cold weather regions are known to generate these proteins for survival. A detailed molecular understanding of how these proteins work could assist in developing synthetic analogs for use in industry. Although the shapes of these proteins vary from completely alpha-helical to globular, they perform the same function. It is the shapes of these proteins that control their recognition and binding to a specific face of ice. Thermal hysteresis proteins modify the morphology of the ice crystal, thereby depressing the freezing point. Currently there are three hypotheses proposed with respect to the antifreeze activity of thermal hysteresis proteins. From structure-function experiments, ice etching experiments, X-ray structures and computer modeling at the ice-vacuum interface, the first recognition and binding hypothesis was proposed and stated that a lattice match of the ice oxygens with hydrogen-bonding groups on the proteins was important. Additional mutagenesis experiments and computer simulations have lead to the second hypothesis, which asserted that the hydrophobic portion of the amphiphilic helix of the type I thermal hysteresis proteins accumulates at the ice-water interface. A third hypothesis, also based on mutagenesis experiments and computer simulations, suggests that the thermal hysteresis proteins accumulate in the ice-water interface and actually influence the specific ice plane to which the thermal hysteresis protein ultimately binds. The first two hypotheses emphasize the aspect of the protein 'binding or accumulating' to specific faces of ice, while the third suggests that the protein assists in the development of the binding site. Our modeling and analysis supports the third hypothesis, however, the first two cannot be completely ruled out at this time. The objective of this paper is to review the computational and experimental efforts during the past 20 years to elucidate the recognition and binding of thermal hysteresis proteins at the ice-vacuum and ice-water interface.