6,780 research outputs found
Ion chemistry in interstellar space
The temperature dependence of the bimolecular reactions of Cl(+), HCl(+), CH(+), CH2(+), N(+), NH(+), and NH2(+) reacting with H2 have been investigated. For Cl(+) and HCl(+) rate constants have been determined over the temperature range of 150 to 400 K. Preliminary data have been obtained for the other systems. The Cl(+)/H2 system shows a weak, but significant positive temperature dependence that could be important in interstellar modeling studies. The HCl(+)/H2 system shows a substantial negative temperature dependence with the rate constant approaching the collision rate at low temperatures. The association reaction CH3(+) + HCN yields CH3 HCN(+) has been theoretically modeled using statistical phase space theory. Both radiative and collisional stabilization have been included. The results are compared with experiment with good agreement obtained over wide variations in T and p. This system is potentially important in the mechanism of large molecule synthesis in interstellar space
The when and where of an emerging crime type: the example of metal theft from the railway network of Great Britain
Metal theft has become an increasingly common crime in recent years, but lack of data has limited research into it. The present study used police-recorded crime data to study the spatial and temporal concentration of metal theft from the railway network of Great Britain. Metal theft was found to exhibit only weak seasonality, to be concentrated at night and to cluster in a few locations close to – but not in – major cities. Repeat-victimisation risk continued for longer than has been found for other crime types. These and other features appear to point to metal theft being a planned, rather than opportunistic, offence and to the role of scrap-metal dealers as facilitators
Gated communities as club goods: segregation or social cohesion?
Gated communities are normally presented in highly negative terms, based on the common assumption that they contribute to social segregation. In contrast to received wisdom this paper argues that the theory of club goods can be used to
understand gating as a response to both real and perceived issues of crime, vandalism and anti-social behaviour. We suggest that gating can help to foster social cohesion by involving a wide spectrum of communities and income groups
to: reduce crime, protect parked vehicles, increase safety and enhance the local environment by preventing unsolicited entry. The paper explores through two case studies, how communities struggling with neighbourhood problems
including crime are using gating as a way of improving their environment rather than abandoning poorer areas of the city to find a safer home in more residentially segregated better off neighbourhoods. If housing and planning policy makers are to take seriously a commitment to resident democracy and local participation, such concerns should not be dismissed out of hand as examples of
'isolationism' or 'particularistic consumerist interests'
Conformations of biopolymers in the gas phase: a new mass spectrometric method
A method is developed for measuring collision cross sections of gas-phase biomolecules using a slightly modified commercial triple quadrupole instrument. The modifications allow accurate stopping potentials to be measured for ions exiting the collision region of the instrument. A simple model allows these curves to be converted to cross sections. In order to account for certain poorly defined experimental parameters (exact ion energy, absolute pressure in the collision cell, etc.) variable parameters are included in the model. These parameters are determined on a case by case basis by normalizing the results to the well known cross section of singly charged bradykinin, Two relatively large systems were studied (cytochrome c and myoglobin) so comparisons could be made to literature values. A number of new peptide systems were then studied in the 9 -14 residue range. These included singly and doubly charged ions of luteinizing hormone releasing hormone (LHRH) substance P, and bombesin in addition to bradykinin. The experimental cross sections were in very good agreement with predictions from extensive molecular dynamics modeling. One interesting result was the experimental observation that the cross section of the doubly charged ions of LHRH, substance P, and bombesin were all smaller than those of the corresponding singly charged ions. Molecular dynamics did not reproduce this result, predicting doubly charged cross sections of the same magnitude or slightly larger than for the singly charged species. The experimental results appear to be correct, however. Possible shortcomings in the modeling procedure for multiply charged ions were suggested that might account for the discrepancy
Playing Video Games as a Supplement to Identity: Insights on Former College Athlete Transitions
Traditionally, researchers of sport and physical activity have considered playing video game to be an obstacle toward optimal health and social outcomes for youth. This study, however, posits video game play not as antithetical to health and physical activity, but as a meaningful forum utilized by former intercollegiate athletes to maintain salient aspects of their sport identities. Through a grounded theory analysis of a sample of 13 former intercollegiate athletes, this study takes initial steps toward a nuanced understanding of the manner in which video games can assist intercollegiate athletes who are transitioning out of elite athletic competition. The findings of the study demonstrate the patterns in the social processes underlying video game play for the former athletes in this sample. Ultimately, it is determined that these former athletes play videos games as an outlet for competition, with competition functioning as a channel through which to connect on an interpersonal level with others, and in turn using the opportunity for interpersonal connection as a means through which to reinforce salient aspects of their sport identities
Efficacy of clip-wrapping in treatment of complex pediatric aneurysms
pre-printPurpose: Pediatric aneurysms (PAs) are distinct from their adult counterparts with respect to typical location, aneurysm type, and known predisposing risk factors. Many strategies have been employed to treat PAs, but, although it has been used frequently in adults, clip-wrapping in pediatric patients has only been reported once. We present a series of pediatric patients that underwent clip-wrapping and discuss this strategy as an effective means of treating unclippable PAs. Methods: Pediatric patients with clip-wrapped aneurysms over a 5-year period were retrospectively identified. Clinical presentation, surgical management, and clinical and radiological outcome of the patients were evaluated. Results: Five pediatric patients with aneurysms were treated with clip-wrapping during the specified period. Three had traumatic pseudoaneurysms, with two subarachnoid hemorrhages from aneurysm rupture. One patient presented with mycotic pseudoaneurysm rupture causing a large intraparenchymal and subarachnoid hemorrhage. Another patient had a dissecting complex saccular lenticulostriate aneurysm with 4 perforating vessels arising from the dome. Four patients had good clinical results, with Glasgow Outcome Scale (GOS) scores of 5 after at least 1-year follow-up (mean 24.2); one patient had a GOS score of 5 at discharge but no additional follow-up. Post-operative neuroimaging demonstrated vessel patency after clip-wrapping with no recurrent hemorrhages or increase in aneurysm size; however, one had progressive occlusion of the UU IR Author Manuscript UU IR Author Manuscript University of Utah Institutional Repository Author Manuscript Bowers et al. 3 artery in a delayed fashion and had a small clinical ischemic event from which she fully recovered. Conclusions: Clip-wrapping appears to be an effective underutilized technique for treatment of pediatric complex aneurysms that cannot be treated with conventional methods. Keywords: Complex aneurysms; pediatric; clip-wrapping Running Title: Clip-wrapping pediatric aneurysms UU IR Author Manuscript UU IR Author Manuscript University of Utah Institutional Repository Author Manuscript
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