2,337 research outputs found
Electronic response of graphene to linelike charge perturbations
The problem of electrostatic screening of a charged line by undoped or weakly
doped graphene is treated beyond the linear-response theory. The induced
electron density is found to be approximately doping independent, n(x)~(log
x)^2/x^2, at intermediate distances x from the charged line. At larger x, twin
p-n junctions may form if the external perturbation is repulsive for graphene
charge carriers. The effect of such inhomogeneities on conductance and quantum
capacitance of graphene is calculated. The results are relevant for transport
properties of graphene grain boundaries and for local electrostatic control of
graphene with ultrathin gates.Comment: Fixed typos and added reference
Behaviour and accidents in young children and adolescents
The Mater-University Study of Pregnancy recruited a cohort of 8,458 Brisbane women during pregnancy. Subsequent follow-ups of mother and child occurred a few days, 6 months, 5 years and 14 years after birth, with the collection of a wide range of biological, sociological and behavioural information as well as measures of mental and physical health. In anticipation of a further cohort follow-up (funded by CARRS-Q) aimed specifically at examining risk-taking behaviour and road crashes in young drivers, the present paper examines the relationship between child and adolescent behaviour and the occurrence of accidents. This indicates that children with behaviour problems, particularly social and attentional disorders at age 5 years are nearly twice as likely to have had an accident in the past three months. While there is some evidence of continuity of accident occurrence (27% of children whose mother’s reported an accident at age 5 years also were also reported to have had an accident requiring medical attention in the last year) this association was weak. Behaviour problems, as measured by the Child Services, police or Juvenile Aid Bureau at age 14 also predict accident occurrence at age 14. ‘Binge drinking’ (consumption of seven or more alcoholic drinks at a time), while rare in this sample (2%) was associated with a doubling of accident risk. The next phase of MUSP will involve administering a questionnaire focused on risk taking behaviour to adolescents, followed up by later record linkage to accident reports and medical records to obtain end-points of road crashes and accident morbidity
A new engineering approach to predict the long-term hydrostatic strength of unplasticized poly(vinyl chloride) pipes
Extruded polymer pipes are qualified using pressurized pipe tests. With these tests the long-term hydrostatic strength is determined by subjecting the pipes to an internal pressure, while measuring the time-to-failure. Although these tests can be accelerated (at higher temperatures), they remain time consuming and require a spacious experimental setup. To circumvent this costly method a model based approach is proposed by which the long-term hydrostatic strength is predicted. Using short term measurements, the input parameters for this approach can be determined. In this engineering approach the effects of physical aging are included. The approach is capable to quantitatively predict the (long-term) failure time of pipe sections under internal pressure
Exercise training and detraining process affects plasma adiponectin level in healthy and spontaneously hypertensive rats
BACKGROUND: Adiponectin levels with long-term swimming exercise have been never investigated in spontaneously hypertensive rats (SHR). OBJECTIVE: This study was aimed to investigate the effects of exercise and detraining process on the adiponectin plasma levels of spontaneously hypertensive rats (SHR) and healthy Wistar-Kyoto rats (WKY). MATERIAL AND METHODS: The rats in the exercise groups were swimming for 10 weeks, 5 days/week, one hour in a day. The detraining rats were left to be sedentary in their cages for 5 weeks after 10 weeks of exercise period. RESULTS: The plasma adiponectin levels decreased in E and SHRE groups compared to the SC and the SHR groups, respectively. In addition, blood pressure was decreased in the exercise groups vs their controls. The adiponectin level was not found to be significantly different in ED and SHRED groups compared to their controls. The blood pressure did not differ between SDC and ED groups, although in the SHRED group it was found to be lower than in SHRSD group rats. CONCLUSION: The results of this study showed that exercise reduced plasma levels of adiponectin in healthy and spontaneously hypertensive rats. However, this difference disappeared at the end of the training processes. Our results suggest, that changes in plasma adiponectin levels are not responsible for changes in blood pressure
Türkiye’de fizyoloji lisansüstü eğitimine genel bakış
A questionnaire was prepared to determine the current situation, characteristics, main problems and solution proposals of post-graduate physiology education in Turkey. The questionnaire was answered by 40% of the physiology departments with post-graduate programs. The results of the questionnaire demonstrate that 31% of master students and 45% of PhD students have academic positions. Most of the post-graduate physiology students are employed in the "academic staff training program" (62% of master and 59% of PhD students). Post-graduate physiology students were mainly composed of biologists (25%) and medical doctors (21%). All or the majority (81%) of postgraduate students have completed their education within the legal periods. We have observed that post-graduate physiology students do not sufficiently benefit from the national and international student exchange programs, scholarships and do not participate in academic activities. Publication rates of the post-graduate thesis in national and international journals are also below the anticipated level. The general problems faced in providing post-graduate physiology education are insufficiency of available academic positions, scholarships, number of academic staff, inadequate financial support in producing qualified research as well as lack of infrastructure. The results of the questionnaire demonstrate that comprehensive studies with broad participation are necessary in order to improve post-graduate education in our country
CHANNEL COMMUNICATION STRATEGY INFLUENCE ON THE PERFORMANCE OF CEMENT MANUFACTURING FIRMS IN KENYA
This study investigated the influence of channel communication strategy on the performance of cement manufacturing firms in Kenya. The study used survey research design. The target population was 469 comprising of 220 distributors, 60 customers, 35 finance staff, 140 sales and distribution department employees and 14 heads of department. A sample size of 216 was chosen using stratified sampling technique. Data was analysed using both descriptive and inferential statistics. The study found that there existed strong positive relationship between communication (r=0.600) and performance of cement manufacturing firms in Kenya. The study recommends that cement companies should ensure regular provision feedback to their clients. Article visualizations
Plasmon reflections by topological electronic boundaries in bilayer graphene
Domain walls separating regions of AB and BA interlayer stacking in bilayer
graphene have attracted attention as novel examples of structural solitons,
topological electronic boundaries, and nanoscale plasmonic scatterers. We show
that strong coupling of domain walls to surface plasmons observed in infrared
nanoimaging experiments is due to topological chiral modes confined to the
walls. The optical transitions among these chiral modes and the band continua
enhance the local ac conductivity, which leads to plasmon reflection by the
domain walls. The imaging reveals two kinds of plasmonic standing-wave
interference patterns, which we attribute to shear and tensile domain walls. We
compute the electronic structure of both wall varieties and show that the
tensile wall contain additional confined bands which produce a
structure-specific contrast of the local conductivity. The calculated plasmonic
interference profiles are in quantitative agreement with our experiments.Comment: 14 pages, 5 figure
Tunable plasmonic reflection by bound 1D electron states in a 2D Dirac metal
We show that surface plasmons of a two-dimensional Dirac metal such as
graphene can be reflected by line-like perturbations hosting one-dimensional
electron states. The reflection originates from a strong enhancement of the
local optical conductivity caused by optical transitions involving these bound
states. We propose that the bound states can be systematically created,
controlled, and liquidated by an ultranarrow electrostatic gate. Using infrared
nanoimaging, we obtain experimental evidence for the locally enhanced
conductivity of graphene induced by a carbon nanotube gate, which supports this
theoretical concept.Comment: 14 pages, 12 figures, submitted to PR
Obstetrical Outcomes of Aboriginal Pregnancies at a Major Urban Hospital
While a number of previous papers have documented the poor general health of Australia's Aboriginal population, relatively few have considered the health of Aborigines living in Australia's urban centres. In this latter instance, Aborigines have access to conventional medical services and they live in a physical environment that does not differ greatly from that experienced by the lower-class white population. Of course, racial, familial and economic differences may continue to influence differentially the perceived accessibility of services to Aborigines and their non-Aboriginal neighbours. This paper compares the pregnancy outcomes of Aboriginal women and non-Aboriginal women living in a major urban centre in Australia. The data indicate that urban Aboriginal women have adverse pregnancy outcomes at one and a half o two times the rate experienced by the non-Aboriginal population. Much of the difference can be attributed to lifestyle variations in the groups being compared
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