1,498 research outputs found
Impurity segregation in graphene nanoribbons
The electronic properties of low-dimensional materials can be engineered by
doping, but in the case of graphene nanoribbons (GNR) the proximity of two
symmetry-breaking edges introduces an additional dependence on the location of
an impurity across the width of the ribbon. This introduces energetically
favorable locations for impurities, leading to a degree of spatial segregation
in the impurity concentration. We develop a simple model to calculate the
change in energy of a GNR system with an arbitrary impurity as that impurity is
moved across the ribbon and validate its findings by comparison with ab initio
calculations. Although our results agree with previous works predicting the
dominance of edge disorder in GNR, we argue that the distribution of adsorbed
impurities across a ribbon may be controllable by external factors, namely an
applied electric field. We propose that this control over impurity segregation
may allow manipulation and fine-tuning of the magnetic and transport properties
of GNRs.Comment: 5 pages, 4 figures, submitte
Primary Care Physiciansâ Experience and Confidence with Genetic Testing and Perceived Barriers to Genomic Medicine
Purpose: Genetic testing is progressing towards use of patientsâ genomes for personalized medicine. Primary care physicians (PCPs) may use genetic tests to screen and assess risk. However, PCPsâ current preparedness for the expanding integration of genetics into practice is uncharacterized. We examined primary care physiciansâ perceptions of and experience with genetic testing. Methods: An anonymous survey was mailed to PCPs across three regional health networks querying opinions of, experience with, confidence in, and perceived barriers to genetic testing. Results: The survey response rate was 37.8%. Respondents believed learning about new genetic advances was important to clinical practice (67.0%). A minority (19.0%) had ordered genetic testing in six months, with cancer risk testing the most frequently ordered. Respondents were not confident in the skills required for using genetic testing in practice. Few respondents felt that they had time to counsel about genetic risk (9.5%) or that most patients could comprehend the concept of risk (27.0%). Conclusions: Primary care physicians had a high opinion of using genetic testing in medicine, but reported little experience or confidence incorporating genetic testing into practice. A majority perceived time constraints and patient comprehension as barriers. These data demonstrate a need for genetics educational resources for physicians and patients
Increased hemorrhagic transformation and altered infarct size and localization after experimental stroke in a rat model type 2 diabetes
<p>Abstract</p> <p>Background</p> <p>Interruption of flow through of cerebral blood vessels results in acute ischemic stroke. Subsequent breakdown of the blood brain barrier increases cerebral injury by the development of vasogenic edema and secondary hemorrhage known as hemorrhagic transformation (HT). Diabetes is a risk factor for stroke as well as poor outcome of stroke. The current study tested the hypothesis that diabetes-induced changes in the cerebral vasculature increase the risk of HT and augment ischemic injury.</p> <p>Methods</p> <p>Diabetic Goto-Kakizaki (GK) or control rats underwent 3 hours of middle cerebral artery occlusion and 21 h reperfusion followed by evaluation of infarct size, hemorrhage and neurological outcome.</p> <p>Results</p> <p>Infarct size was significantly smaller in GK rats (10 ± 2 vs 30 ± 4%, p < 0.001). There was significantly more frequent hematoma formation in the ischemic hemisphere in GK rats as opposed to controls. Cerebrovascular tortuosity index was increased in the GK model (1.13 ± 0.01 vs 1.34 ± 0.06, P < 0.001) indicative of changes in vessel architecture.</p> <p>Conclusion</p> <p>These findings provide evidence that there is cerebrovascular remodeling in diabetes. While diabetes-induced remodeling appears to prevent infarct expansion, these changes in blood vessels increase the risk for HT possibly exacerbating neurovascular damage due to cerebral ischemia/reperfusion in diabetes.</p
Constructing meaning about the delinquency of young girls in public-housing neighbourhoods
UID/SOC/04647/2013
SFRH/BPD/116119/2016Rooted in the theoretical approaches of social ecology and in childhood studies, the Ph.D. research project on which this paper is based aimed to achieve a better understanding of childrenâs socialization processes in multi-problematic spaces, particularly concerning their involvement in violence and delinquency. A case study based on ethnographic research and child-centred methods was carried out in six public-housing neighbourhoods in Portugal, which were chosen because they had relatively high levels of social deprivation, violence and crime. The specificity of the social group under studyâchildren aged from 6 to 12 years oldâand their living conditions, led us to extend the data collected by trying to learn, from the girls, the reasoning and the meanings they assign to their own actions in daily social practices. The intention was to study the features of girlsâ socialization in the field through their own accounts of their lives and to examine their perspectives on offending behaviours. The genderized process of social learning in delinquency identified in the girlsâ conversation is an important variable, as familial and social experiences tend to facilitate their entry into delinquency. The transmission of delinquent values takes place essentially within the female family circle or via female peers, rather than from the influence of male individuals.authorsversionpublishe
Whatâs Sex (Composition) Got to Do with It? The Importance of Sex Composition of Gangs for Female and Male Membersâ Offending and Victimization
Sex composition of groups has been theorized in organizational sociology and found in prior work to structure female and male membersâ behaviors and experiences. Peer group and gang literature similarly finds that the sex gap in offending varies across groups of differing sex ratios. Drawing on this and other research linking gang membership, offending, and victimization, we examine whether sex composition of gangs is linked to sex differences in offending in this sample, further assess whether sex composition similarly structures femalesâ and malesâ victimization experiences, and if so, why. Self-report data from gang members in a multi-site, longitudinal study of 3,820 youths are employed. Results support previous findings about variations in member delinquency by both sex and sex composition of the gang and also indicate parallel variations in membersâ victimization. These results are further considered within the context of facilitating effects such as gender dynamics, gang characteristics, and normative orientation
One-pot hydrogen peroxide and hydrohalic acid induced ring closure and selective aromatic halogenation to give new ring-fused benzimidazoles
A new series of selectively dichlorinated and dibrominated five to eight-membered ring [1,2-a] fused benzimidazoles and [1,4]oxazino[4,3-a]benzimidazoles are synthesized in mostly high yields of >80% using the reaction of hydrogen peroxide and hydrohalic acid with commercially available o-cyclic amine substituted anilines. Domestic bleach with HCl is also capable of a one-pot ring-closure and chlorination
The design, construction and performance of the MICE scintillating fibre trackers
This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierCharged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented.This work was supported by the Science and Technology Facilities Council under grant numbers PP/E003214/1, PP/E000479/1, PP/E000509/1, PP/E000444/1, and through SLAs with STFC-supported laboratories. This work was also supportedby the Fermi National Accelerator Laboratory, which is operated by the Fermi Research Alliance, under contract No. DE-AC02-76CH03000 with the U.S. Department of Energy, and by the U.S. National Science Foundation under grants PHY-0301737,PHY-0521313, PHY-0758173 and PHY-0630052. The authors also acknowledge the support of the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan
How 911 callers and callâtakers impact police encounters with the public: The case of the Henry Louis Gates Jr. arrest
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156456/2/capp12508_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156456/1/capp12508.pd
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