Disorder enabled band structure engineering of a topological insulator surface

Three dimensional topological insulators are bulk insulators with $\mathbf{Z}_2$ topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by non-magnetic disorder, and have been adopted as the basis for a wide range of proposals to achieve new quasiparticle species and device functionality. Recent studies have yielded a surprise by showing that in spite of resisting localization, topological insulator surface electrons can be reshaped by defects into distinctive resonance states. Here we use numerical simulations and scanning tunneling microscopy data to show that these resonance states have significance well beyond the localized regime usually associated with impurity bands. At native densities in the model Bi$_2$X$_3$ (X=Bi, Te) compounds, defect resonance states are predicted to generate a new quantum basis for an emergent electron gas that supports diffusive electrical transport

Irreversible proliferation of magnetic moments at cleaved surfaces of the topological Kondo insulator SmB6

The compound SmB$_6$ is the best established realization of a topological Kondo insulator, in which a topological insulator state is obtained through Kondo coherence. Recent studies have found evidence that the surface of SmB$_6$ hosts ferromagnetic domains, creating an intrinsic platform for unidirectional ballistic transport at the domain boundaries. Here, surface-sensitive X-ray absorption (XAS) and bulk-sensitive resonant inelastic X-ray scattering (RIXS) spectra are measured at the Sm N$_{4,5}$-edge, and used to evaluate electronic symmetries, excitations and temperature dependence near the surface of cleaved samples. The XAS data show that the density of large-moment atomic multiplet states on a cleaved surface grows irreversibly over time, to a degree that likely exceeds a related change that has recently been observed in the surface 4f orbital occupation

Postcode lottery? Hospital transfers from one London prison and responsible catchment area

Aims and method To consider the link between responsible commissioner and delayed prison transfers. All hospital transfers from one London prison in 2006 were audited and reviewed by the prisoner's borough of origin. Results Overall, 80 prisoners were transferred from the audited prison to a National Health Service (NHS) facility in 2006: 26% had to wait for more than 1 month for assessment by the receiving hospital unit and 24% had to wait longer than 3 months to be transferred. These 80 individuals were the responsibility of 16 different primary care trusts. Of the delayed transfer cases (n=19), the services commissioned by three primary care trusts were responsible for the delays. Clinical implications There are significant differences in performance between different primary care trusts related to hospital transfers of prisoners, with most hospitals able to admit urgent cases within 3 months. This suggests that a postcode lottery operates for prisoners requiring hospital transfer. Data from prison services may be useful in monitoring and improving the performance of local NHS services

Economic evaluation of the introduction of the Prostate Health Index as a rule-out test to avoid unnecessary biopsies in men with prostate specific antigen levels of 4-10 in Hong Kong

A recent study showed that the Prostate Health Index may avoid unnecessary biopsies in men with prostate specific antigen 4-10ng/ml and normal digital rectal examination in the diagnosis of prostate cancer in Hong Kong. This study aimed to conduct an economic evaluation of the impact of adopting this commercially-available test in the Hong Kong public health service to determine whether further research is justified. A cost-consequence analysis was undertaken comparing the current diagnostic pathway with a proposed diagnostic pathway using the Prostate Health Index. Data for the model was taken from a prospective cohort study recruited at a single-institution and micro-costing studies. Using a cut off PHI score of 35 to avoid biopsy would cost HK$3,000 and save HK$7,988 per patient in biopsy costs and HK$511 from a reduction in biopsy-related adverse events. The net cost impact of the change was estimated to be HK$5,500 under base case assumptions. At the base case sensitivity and specificity for all grades of cancer (61.3% and 77.5% respectively) all grade cancer could be missed in 4.22% of the population and high grade cancer in 0.53%. The introduction of the prostate health index into the diagnostic pathway for prostate cancer in Hong Kong has the potential to reduce biopsies, biopsy costs and biopsy-related adverse events. Policy makers should consider the clinical and economic impact of this proposal

Integration of behavioral frequency and intention information in young children’s trait attributions.

Two experiments examined three- to six-year-olds' use of frequency and intention information to make trait attributions and behavioral predictions. In experiment 1, participants were told a story about an actor who behaved positively once or four times on purpose or incidentally. Children were most likely to make trait-consistent behavioral predictions after hearing about several positive, intentional behaviors. Trait attributions were largely positive. Experiment 2 examined children's use of the same cues concerning negative behavioral outcomes. Participants tended to predict that actors who engaged in negative behavior would do so again, irrespective of intention, although younger children required more exemplars than older children. Participants were most likely to make negative trait attributions after hearing about multiple intentional behaviors; however, there was reluctance with age to describe actors as mean. Implications for children's ‘theory of personality’ are discussed

RhoGDIβ-induced hypertrophic growth in H9c2 cells is negatively regulated by ZAK

We found that overexpression of RhoGDIβ, a Rho GDP dissociation inhibitor, induced hypertrophic growth and suppressed cell cycle progression in a cultured cardiomyoblast cell line. Knockdown of RhoGDIβ expression by RNA interference blocked hypertrophic growth. We further demonstrated that RhoGDIβ physically interacts with ZAK and is phosphorylated by ZAK in vitro, and this phosphorylation negatively regulates RhoGDIβ functions. Moreover, the ZAK-RhoGDIβ interaction may maintain ZAK in an inactive hypophosphorylated form. These two proteins could negatively regulate one another such that ZAK suppresses RhoGDIβ functions through phosphorylation and RhoGDIβ counteracts the effects of ZAK by physical interaction. Knockdown of ZAK expression in ZAK- and RhoGDIβ-expressing cells by ZAK-specific RNA interference restored the full functions of RhoGDIβ

Evaluación de campañas de promoción de la salud: Caso proyecto “Salvando vidas”

La evaluación en las campañas de salud, pueden mejorar los indicadores de salud, la realidad es que existe una escasa cultura en este ámbito. El objetivo de este proyecto es evaluar el impacto de la campaña “salvando vidas”. Metodología descriptiva mixta, con población intervenida y sin intervención. Post-test cuantitativo (encuesta) aplicado a 517 estudiantes de secundaria y preparatoria de 8 jurisdicciones sanitarias del Estado de Nuevo León. México. Pre-test cualitativo (Grupos de discusión) aplicado a 6 grupos de estudiantes; para obtener el comportamiento efectivo atribuible a una campaña

ZAK negatively regulates RhoGDIβ-induced Rac1-mediated hypertrophic growth and cell migration

RhoGDIβ, a Rho GDP dissociation inhibitor, induced hypertrophic growth and cell migration in a cultured cardiomyoblast cell line, H9c2. We demonstrated that RhoGDIβ plays a previously undefined role in regulating Rac1 expression through transcription to induce hypertrophic growth and cell migration and that these functions are blocked by the expression of a dominant-negative form of Rac1. We also demonstrated that knockdown of RhoGDIβ expression by RNA interference blocked RhoGDIβ-induced Rac1 expression and cell migration. We demonstrated that the co-expression of ZAK and RhoGDIβ in cells resulted in an inhibition in the activity of ZAK to induce ANF expression. Knockdown of ZAK expression in ZAK-RhoGDIβ-expressing cells by ZAK-specific RNA interference restored the activities of RhoGDIβ

Selenium supplementation and insulin resistance in a randomized, clinical trial

Objective: While controversial, observational and randomized clinical trial data implicate the micronutrient selenium (Se) in the development of type 2 diabetes (T2D). The aim of this study was to test the hypothesis that Se supplementation adversely affects pancreatic beta-cell function and insulin sensitivity. Research design and methods: In a subset of 400 individuals participating in a randomized, placebocontrolled trial of Se at 200 mu g/day for colorectal adenomatous polyps, fasting plasma glucose and insulin were measured before randomization and within 6 months of completing intervention. Change in the homeostasis model assessment-beta cell function (HOMA2-%beta) and insulin sensitivity (HOMA2-%S) were compared between arms. A subgroup of 175 (79 Se and 96 placebo) participants underwent a modified oral glucose tolerance test (mOGTT) at the end of intervention and change in glucose values was assessed. Results: No statistically significant differences were observed for changes in HOMA2-%beta or HOMA2-%S between those who received Se compared with placebo. After a mean of 2.9 years on study, mean HOMA2-%beta values were 3.1 +/- 24.0 and 3.1 +/- 29.8 for the Se and placebo groups, respectively (p=0.99). For HOMA2-%S, the values were -0.5 +/- 223.2 and 80.9 +/- 1530.9 for the Se and placebo groups, respectively (p=1.00). Stratification by sex or age did not reveal any statistically significant effects on insulin sensitivity by treatment group. For mOGTT, mean baseline fasting blood glucose concentrations were significantly higher among participants in the placebo group compared with the Se group (96.6 +/- 14.6 and 92.3 +/- 12.0, respectively; p=0.04), a trend which remained through the 20 min assessment. Conclusions: These findings do not support a significant adverse effect of daily Se supplementation with 200 mu g/day of selenized yeast on beta-cell function or insulin sensitivity as an explanation for previously reported associations between Se and T2D. Further clarification of longer term effects of Se is needed.National Cancer Institute Cancer Center Support Grant [P30 CA023074]; NIH/NCI [R01CA151708, P01 CA041108]; NIH [R01DK047396]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]