Drexel University

About: Drexel University is a education organization based out in Philadelphia, Pennsylvania, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 26770 authors who have published 51438 publications receiving 1949443 citations. The organization is also known as: Drexel & Drexel Institute.

An age-related sprouting transcriptome provides molecular control of axonal sprouting after stroke

Abstract: Stroke is an age-related disease. Recovery after stroke is associated with axonal sprouting in cortex adjacent to the infarct. The molecular program that induces a mature cortical neuron to sprout a new connection after stroke is not known. We selectively isolated neurons that sprout a new connection in cortex after stroke and compared their whole-genome expression profile to that of adjacent, non-sprouting neurons. This 'sprouting transcriptome' identified a neuronal growth program that consists of growth factor, cell adhesion, axonal guidance and cytoskeletal modifying molecules that differed by age and time point. Gain and loss of function in three distinct functional classes showed new roles for these proteins in epigenetic regulation of axonal sprouting, growth factor-dependent survival of neurons and, in the aged mouse, paradoxical upregulation of myelin and ephrin receptors in sprouting neurons. This neuronal growth program may provide new therapeutic targets and suggest mechanisms for age-related differences in functional recovery.

Novel pro- and anti-recombination activities of the Bloom’s syndrome helicase

Abstract: Bloom's syndrome (BS) is an autosomal recessive disorder characterized by a strong cancer predisposition The defining feature of BS is extreme genome instability The gene mutated in Bloom's syndrome, BLM, encodes a DNA helicase (BLM) of the RecQ family BLM plays a role in homologous recombination; however, its exact function remains controversial Mutations in the BLM cause hyperrecombination between sister chromatids and homologous chromosomes, indicating an anti-recombination role Conversely, other data show that BLM is required for recombination It was previously shown that in vitro BLM helicase promotes disruption of recombination intermediates, regression of stalled replication forks, and dissolution of double Holliday junctions Here, we demonstrate two novel activities of BLM: disruption of the Rad51-ssDNA (single-stranded DNA) filament, an active species that promotes homologous recombination, and stimulation of DNA repair synthesis Using in vitro reconstitution reactions, we analyzed how different biochemical activities of BLM contribute to its functions in homologous recombination

The impact of developer responsiveness on perceptions of usefulness and ease of use: an extension of the technology acceptance model

Abstract: The Technology Acceptance Model (TAM) suggests that the perceived usefulness (PU) and the perceived ease of use (PEOU) of an information system (IS) are major determinants of its use. Previous research has demonstrated the validity of this model across a wide variety of IS types. However, prior research has not identified antecedents of PU and there has been only limited research on the antecedents of PEOU. Consequently, research has provided little guidance to IS managers on methods to increase use by augmenting PU and PEOU.Viewing IS development as an instance of Social Exchange Theory (SET), this study proposes that IS managers can influence both the PU and the PEOU of an IS through a constructive social exchange with the user. One means of building and maintaining a constructive social exchange is through developer responsiveness. The results of this study, examining the adoption of an expert system, indeed support this notion. Specifically, developer responsiveness strongly influenced both PU and PEOU, but only indirectly affected actual behavior --- IS use --- in accordance with the predictions of SET. An extension of TAM based on SET is presented and the implications of this extended model are discussed from both a managerial and theoretical perspective.