scispace - formally typeset
Search or ask a question
Institution

Saint Anselm College

EducationManchester, New Hampshire, United States
About: Saint Anselm College is a education organization based out in Manchester, New Hampshire, United States. It is known for research contribution in the topics: Nurse education & Extinction (psychology). The organization has 255 authors who have published 522 publications receiving 7222 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: It is found that despite the large negative electrostatic potential formed between two juxtaposed DNA helices, a bulk counterion concentration as small as 50 mM provides sufficient electrostatic screening to prohibit significant interaction beyond an interhelical separation of 3 nm in both hooked and free juxtapositions.
Abstract: Type II topoisomerases resolve problematic DNA topologies such as knots, catenanes, and supercoils that arise as a consequence of DNA replication and recombination. Failure to remove problematic DNA topologies prohibits cell division and can result in cell death or genetic mutation. Such catastrophic consequences make topoisomerases an effective target for antibiotics and anticancer agents. Despite their biological and clinical importance, little is understood about how a topoisomerase differentiates DNA topologies in a molecule that is significantly larger than the topoisomerase itself. It has been proposed that type II topoisomerases recognize angle and curvature between two DNA helices characteristic of knotted and catenated DNA to account for the enzyme's preference to unlink instead of link DNA. Here we consider the electrostatic potential of DNA juxtapositions to determine the possibility of juxtapositions occurring through Brownian diffusion. We found that despite the large negative electrostatic potential formed between two juxtaposed DNA helices, a bulk counterion concentration as small as 50 mM provides sufficient electrostatic screening to prohibit significant interaction beyond an interhelical separation of 3 nm in both hooked and free juxtapositions. This suggests that instead of electrostatics, mechanical forces such as those occurring in anaphase, knots, catenanes, or the writhe of supercoiled DNA may be responsible for the formation of DNA juxtapositions.

22 citations

Journal ArticleDOI
TL;DR: The results support and extend the limited number of other studies by demonstrating extinction and spontaneous recovery of responding discriminated by two distinct drugs.
Abstract: Studies regarding extinction and spontaneous recovery of the discriminative stimulus effects of drugs are limited. Eight rats were initially trained to discriminate nicotine (0.4 mg/kg) vs. ethanol (800 mg/kg). For four rats, itraperitaneal (IP) administrations of nicotine fifteen minutes prior to fifteen-minute training sessions served as a discriminative stimulus (SD) for predicting food-reinforced lever pressing (VI-1 min). On other sessions ethanol functioned in predicting nonreinforcement (SΔ). The stimulus roles of the drugs were counterbalanced for the remaining four rats. SΔ and SD sessions alternated quasi-randomly with two daily sessions at 1000 and 1400 hours. Discriminative control was not disrupted following ten extinction sessions under a non-drug/saline condition, but was disrupted following extinction sessions under the original training drugs. Instances of spontaneous recovery (SR) occurred throughout extinction under the drug condtions. There was no evidence for SR two weeks following extinction, but partial recovery four weeks following the final extinction phase. Contextual status (context renewal) had neither a restorative or disruptive impact on extiguished or discriminated responding, respectively. Theser results support and extend the limited number of other studies by demonstrating extinction and spontaneous recovery of responding discriminated bytwo distinct drugs. Some theoretical interpretations regarding history effects and training in the context of drug discrimination are entertained.

22 citations

Journal ArticleDOI
TL;DR: An evaluation of a change in practice led to permanent implementation of an open visitation policy in this PACU.

22 citations

Journal ArticleDOI
TL;DR: Results suggest that PWMCI are less resilient in the face of daily stress than are CHOAs in terms of negative affect, perhaps because of declines in reserve capacity.
Abstract: Daily experiences of stress are common and have been associated with worse affect among older adults. People with mild cognitive impairment (PWMCI) have measurable memory deficits in between normal cognition and dementia and have been identified as having greater psychological distress than cognitively healthy older adults (CHOAs). Little is known about whether daily stressors contribute to distress among PWMCI. We hypothesized that compared with CHOAs, PWMCI would have higher daily negative affect and lower daily positive affect, report greater numbers and severity of daily stressors, and experience greater emotional reactivity to daily stressors. Fifteen clinically diagnosed PWMCI and 25 CHOAs completed daily reports of stressors, stressor severity, and positive and negative affect over an 8-day period. PWMCI reported higher daily negative affect, lower daily positive affect, and higher numbers and greater severity of memory stressors but did not differ from CHOAs in numbers or severity of general stressors. Cognitive status was a moderator of the daily stress-affect relationship. Days with greater numbers and severity of general daily stressors were associated with higher negative affect only for PWMCI. The numbers and severity of memory stressors were not associated with negative affect. In addition, more severe general daily stressors and memory stressors were associated with lower positive affect for all participants. Results suggest that PWMCI are less resilient in the face of daily stress than are CHOAs in terms of negative affect, perhaps because of declines in reserve capacity. The study presents a promising approach to understanding stress and coping in predementia states of cognition.

22 citations

Journal ArticleDOI
TL;DR: This investigation of open-loop failure conditions has led to new insights such as the reorientation of the fielder, and it supports the use of maintaining matching rates of vertical and lateral optical ball movement consistent with primacy of the LOT control mechanism even when interception is unachievable.
Abstract: P. McLeod, N. Reed, and Z. Dienes (2002) argued that the linear optical trajectory (LOT) strategy incorrectly cues fielders to run forward for balls headed beyond them. The authors of this article explain that the downward optical curvature found for balls landing beyond the fielder's initial position occurs because the balls reorient the direction the fielder is facing during pursuit. Thus, when downward optical curvature begins, the ball is headed to land in front of where the fielder is facing and running. This investigation of open-loop failure conditions has led to new insights such as the reorientation of the fielder, and it supports the use of maintaining matching rates of vertical and lateral optical ball movement consistent with primacy of the LOT control mechanism even when interception is unachievable.

21 citations


Authors

Showing all 268 results

Network Information
Related Institutions (5)
University of Wisconsin–Milwaukee
28K papers, 936.4K citations

77% related

Miami University
19.5K papers, 568.4K citations

76% related

Bowling Green State University
16K papers, 482.5K citations

76% related

Ohio University
25.9K papers, 662.2K citations

76% related

Baylor University
21.9K papers, 750.6K citations

76% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20237
202211
202134
202038
201930
201825