Shot Noise in Mesoscopic Diffusive Andreev Wires

We study shot noise in mesoscopic diffusive wires between a normal and a superconducting terminal. We particularly focus on the regime, in which the proximity-induced reentrance effect is important. We will examine the difference between a simple Boltzmann-Langevin description, which neglects induced correlations beyond the simple conductivity correction, and a full quantum calculation. In the latter approach, it turns out that two Andreev pairs propagating coherently into the normal metal are anti-correlated for E<E_c, where E_c=D/L^2 is the Thouless energy. In a fork geometry the flux-sensitive suppression of the effective charge was confirmed experimentally.Comment: 12 pages, proceedings of the NATO ARW MQO, Bled, Sloveni

Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes

Background The cardiovascular effect of liraglutide, a glucagon-like peptide 1 analogue, when added to standard care in patients with type 2 diabetes, remains unknown. Methods In this double-blind trial, we randomly assigned patients with type 2 diabetes and high cardiovascular risk to receive liraglutide or placebo. The primary composite outcome in the time-to-event analysis was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The primary hypothesis was that liraglutide would be noninferior to placebo with regard to the primary outcome, with a margin of 1.30 for the upper boundary of the 95% confidence interval of the hazard ratio. No adjustments for multiplicity were performed for the prespecified exploratory outcomes. Results A total of 9340 patients underwent randomization. The median follow-up was 3.8 years. The primary outcome occurred in significantly fewer patients in the liraglutide group (608 of 4668 patients [13.0%]) than in the placebo group (694 of 4672 [14.9%]) (hazard ratio, 0.87; 95% confidence interval [CI], 0.78 to 0.97; P<0.001 for noninferiority; P=0.01 for superiority). Fewer patients died from cardiovascular causes in the liraglutide group (219 patients [4.7%]) than in the placebo group (278 [6.0%]) (hazard ratio, 0.78; 95% CI, 0.66 to 0.93; P=0.007). The rate of death from any cause was lower in the liraglutide group (381 patients [8.2%]) than in the placebo group (447 [9.6%]) (hazard ratio, 0.85; 95% CI, 0.74 to 0.97; P=0.02). The rates of nonfatal myocardial infarction, nonfatal stroke, and hospitalization for heart failure were nonsignificantly lower in the liraglutide group than in the placebo group. The most common adverse events leading to the discontinuation of liraglutide were gastrointestinal events. The incidence of pancreatitis was nonsignificantly lower in the liraglutide group than in the placebo group. Conclusions In the time-to-event analysis, the rate of the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke among patients with type 2 diabetes mellitus was lower with liraglutide than with placebo. (Funded by Novo Nordisk and the National Institutes of Health; LEADER ClinicalTrials.gov number, NCT01179048 .)

Full Counting Statistics of Superconductor--Normal-Metal Heterostructures

The article develops a powerful theoretical tool to obtain the full counting statistics. By a slight extension of the standard Keldysh method we can access immediately all correlation functions of the current operator. Embedded in a quantum generalization of the circuit theory of electronic transport, we are able to study the full counting statistics of a large class of two-terminal contacts and multi-terminal structures, containing superconductors and normal metals as elements. The practical use of the method is demonstrated in many examples.Comment: 35 pages, contribution to "Quantum Noise", ed. by Yu.V. Nazarov and Ya.M. Blanter, minor changes in text, references adde

A constitutive law for dense granular flows

A continuum description of granular flows would be of considerable help in predicting natural geophysical hazards or in designing industrial processes. However, the constitutive equations for dry granular flows, which govern how the material moves under shear, are still a matter of debate. One difficulty is that grains can behave like a solid (in a sand pile), a liquid (when poured from a silo) or a gas (when strongly agitated). For the two extreme regimes, constitutive equations have been proposed based on kinetic theory for collisional rapid flows, and soil mechanics for slow plastic flows. However, the intermediate dense regime, where the granular material flows like a liquid, still lacks a unified view and has motivated many studies over the past decade. The main characteristics of granular liquids are: a yield criterion (a critical shear stress below which flow is not possible) and a complex dependence on shear rate when flowing. In this sense, granular matter shares similarities with classical visco-plastic fluids such as Bingham fluids. Here we propose a new constitutive relation for dense granular flows, inspired by this analogy and recent numerical and experimental work. We then test our three-dimensional (3D) model through experiments on granular flows on a pile between rough sidewalls, in which a complex 3D flow pattern develops. We show that, without any fitting parameter, the model gives quantitative predictions for the flow shape and velocity profiles. Our results support the idea that a simple visco-plastic approach can quantitatively capture granular flow properties, and could serve as a basic tool for modelling more complex flows in geophysical or industrial applications.Comment: http://www.nature.com/nature/journal/v441/n7094/abs/nature04801.htm

Shot noise in mesoscopic systems

This is a review of shot noise, the time-dependent fluctuations in the electrical current due to the discreteness of the electron charge, in small conductors. The shot-noise power can be smaller than that of a Poisson process as a result of correlations in the electron transmission imposed by the Pauli principle. This suppression takes on simple universal values in a symmetric double-barrier junction (suppression factor 1/2), a disordered metal (factor 1/3), and a chaotic cavity (factor 1/4). Loss of phase coherence has no effect on this shot-noise suppression, while thermalization of the electrons due to electron-electron scattering increases the shot noise slightly. Sub-Poissonian shot noise has been observed experimentally. So far unobserved phenomena involve the interplay of shot noise with the Aharonov-Bohm effect, Andreev reflection, and the fractional quantum Hall effect.Comment: 37 pages, Latex, 10 figures (eps). To be published in "Mesoscopic Electron Transport," edited by L. P. Kouwenhoven, G. Schoen, and L. L. Sohn, NATO ASI Series E (Kluwer Academic Publishing, Dordrecht

How and Why Parents Guide the Media Use of Young Children

Abstract Children use electronic screens at ever younger ages, but there is still little empirical research on howand why parents mediate this media use. In line with Vygotsky’s zone of proximal development, we explored whether children’s media skills and media activities, next to parents’ attitudes about media for children, and several child and parent-family characteristics, predicted parental mediation practices. Furthermore, we investigated children’s use and ownership of electronic screens in the bedroomin relationship to the child’s media skills. Data from an online survey among 896 Dutch parents with young children (0–7 years) showed that children’s use and ownership of TV, game consoles, computers and touchscreens, primarily depended on their media skills and age, not on parent’s attitudes about media for children. Only touchscreens were used more often by children, when parents perceived media as helpful in providing moments of rest for the child. In line with former studies, parents consistently applied co-use, supervision, active mediation, restrictive mediation, and monitoring, depending on positive and negative attitudes about media. The child’s media skills andmedia activities, however, had stronger relationshipswith parental mediation styles, whereas age was not related. Canonical discriminant analysis, finally, captured how the five mediation strategies varied among infants, toddlers, preschoolers, and early childhood children, predominantly as a result of children’s media skills, and media activities, i.e., playing educational games and passive entertainment use

Bedside Interactions from the Other Side of the Bedrail

To assess the importance to patients of various aspects of bedside interactions with physician teams. Design : Cross-sectional survey. Setting : VA hospital. Patients : Ninety-seven medical inpatients. Intervention : Survey of 44 questions including short answer, multiple choice, and Likert-type questions. Measurements and Main Results : Data analysis included descriptive statistics. The sample was predominantly male, with a mean age of 62. Overall satisfaction with the hospital experience and with the team of doctors were both high (95% and 96% reported being very or mostly satisfied, respectively). Patients reported learning about several issues during their interactions with the teams; the 3 most highly rated areas were new problems, tests that will be done, and treatments that will be done. Most patients (76%) felt that their teams cared about them very much. Patients were made comfortable when the team showed that they cared, listened, and appeared relaxed (reported by 63%, 57%, and 54%, respectively). Patients were made uncomfortable by the team using language they did not understand (22%) and when several people examined them at once (13%). Many (58%) patients felt personally involved in teaching. The majority of patients liked having medical students and residents involved in their care (69% and 64%, respectively). Conclusions : Patients have much to teach about what is important about interacting with physician teams. Although patients' reactions to team interactions are generally positive, patients are different with respect to what makes them comfortable and uncomfortable. Taking their preferences into account could improve the experience of being in a teaching hospital.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75456/1/j.1525-1497.2005.40192.x.pd

Awareness of school students on sexually transmitted infections (STIs) and their sexual behavior: a cross-sectional study conducted in Pulau Pinang, Malaysia

<p>Abstract</p> <p>Background</p> <p>Sexually transmitted Infections (STIs) rank among the most important health issues for the people especially the young adults worldwide. Young people tend to engage in sexual activity at younger ages in the past decade than in the 1970s, and 1980s. Knowledge is an essential precursor of sexual risk reduction. A cross-sectional study was conducted in Pulau Pinang, Malaysia, to produce the baseline information about school students' awareness and perception about sexually transmitted Infections (STIs) and their sexual activity to help establish control and education programmes.</p> <p>Methods</p> <p>Students from form 4 (aged between 15 to 16 years), form 5 (aged between 16 to 17 years) and form 6 (aged between 18 to 20 years) in their class rooms were approached and asked to complete self administered and anonymous pre-validated questionnaires. SPSS for windows version 13 was used to analyze the results statistically and results were presented in tabular form.</p> <p>Results</p> <p>Data was collected from 1139 students aged between 15 to 20 years, 10.6% of which claimed that they never heard about STIs. Sexual experience related significantly with gender, race, and education level. Approximately 12.6% claimed to have sexual experience of which 75.7% had their sexual debut at 15-19 years and 38.2% were having more than 3 partners. Sexual experience was found to be significantly associated with gender (<it>p </it>= 0.003), ethnicity (<it>p </it>= 0.001) and education level (<it>p </it>= 0.030). However, multiple partner behaviour was significantly associated only with gender (<it>p </it>= 0.010). Mean knowledge score was 11.60 ± 8.781 and knowledge level was significantly associated with religion (p = 0.005) education level (<it>p </it>= 0.000), course stream (<it>p </it>= 0.000), socioeconomic class (<it>p </it>= 0.000) and sexual experience (<it>p </it>= 0.022).</p> <p>Conclusions</p> <p>It was concluded that school students have moderate level of knowledge about STIs although they are sexually active. Interventions such as reinforcing the link between STIs and HIV/AIDS, assessing the current status of sexuality education in schools and arranging public talks and seminars focusing on STIs prevention education are needed to improve their awareness.</p

Cancer Incidence among Former Love Canal Residents

Ba c k g r o u n d: The Love Canal was a rectangular 16-acre, 10-ft-deep chemical waste landfill situated in a residential neighborhood in Niagara Falls, New York. This seriously contaminated site came to public attention in 1978. Only one prior study examined cancer incidence in former residents of the Love Canal neighborhood (LC). Objective: In this study we aimed to describe cancer incidence in former LC residents from 1979 to 1996 and to investigate whether it differs from that of New York State (NYS) and Niagara County (NC). Me t h o d s: From 1978 to 1982, we interviewed 6,181 former residents, and 5,052 were eligible to be included in this study. In 1996, we identified 304 cancer diagnoses in this cohort using the NYS Cancer Registry. We compared LC cancer incidence with that of NYS and NC using standardized incidence ratios (SIRs), and we compared risks within the LC group by potential exposure to the landfill using survival analysis. Res u l t s: SIRs were elevated for cancers of the bladder [SIR NYS = 1.44; 95 % confidence interval (CI), 0.91–2.16] and kidney (SIR NYS = 1.48; 95 % CI, 0.76–2.58). Although CIs included 1.00, other studies have linked these cancers to chemicals similar to those found at Love Canal. We also found higher rates of bladder cancer among residents exposed as children, based on two cases. Co n c l u s i o n s: In explaining these excess risks, the role of exposure to the landfill is unclear given such limitations as a relatively small and incomplete study cohort, imprecise exposure measurements, and the exclusion of cancers diagnosed before 1979. Given the relatively young age of the cohort, further surveillance is warranted. Key w o r d s: cancer, community health, exposure assessment, hazardous waste sites, Love Canal. Environ Health Perspect 117:1265–1271 (2009). doi:10.1289/ehp.0800153 available vi