Property (T) for non-unital C*-algebras

Inspired by the recent work of Bekka, we study two reasonable analogues of property (T) for not necessarily unital C*-algebras. The stronger one of the two is called ``property (T)'' and the weaker one is called ``property (T_{e})''. It is shown that all non-unital C*-algebras do not have property (T) (neither do their unitalizations). Moreover, all non-unital $\sigma$-unital C*-algebras do not have property (T_e).Comment: 7 pages; to appear in J. Math. Anal. App

Constructive Gelfand duality for C*-algebras

We present a constructive proof of Gelfand duality for C*-algebras by reducing the problem to Gelfand duality for real C*-algebras.Comment: 6page

Heat shock induces rapid resorption of primary cilia

Primary cilia are involved in important developmental and disease pathways, such as the regulation of neurogenesis and tumorigenesis. They function as sensory antennae and are essential in the regulation of key extracellular signalling systems. We have investigated the effects of cell stress on primary cilia. Exposure of mammalian cells in vitro, and zebrafish cells in vivo, to elevated temperature resulted in the rapid loss of cilia by resorption. In mammalian cells loss of cilia correlated with a reduction in hedgehog signalling. Heat-shock-dependent loss of cilia was decreased in cells where histone deacetylases (HDACs) were inhibited, suggesting resorption is mediated by the axoneme-localised tubulin deacetylase HDAC6. In thermotolerant cells the rate of ciliary resorption was reduced. This implies a role for molecular chaperones in the maintenance of primary cilia. The cytosolic chaperone Hsp90 localises to the ciliary axoneme and its inhibition resulted in cilia loss. In the cytoplasm of unstressed cells, Hsp90 is known to exist in a complex with HDAC6. Moreover, immediately after heat shock Hsp90 levels were reduced in the remaining cilia. We hypothesise that ciliary resorption serves to attenuate cilia-mediated signalling pathways in response to extracellular stress, and that this mechanism is regulated in part by HDAC6 and Hsp90

The Dixmier property and tracial states for C*-algebras

A.T. was partially supported by an NSERC Postdoctoral Fellowship and through the EPSRC grant EP/N00874X/1. Acknowledgements We are grateful to Luis Santiago for helpful discussions at an early stage of this investigation. We would also like to thank the referee for providing helpful comments, which have led to a number of improvements.Peer reviewedPublisher PD

Classification of Extensions of Classifiable C*-algebras

We classify extensions of certain classifiable C*-algebras using the six term exact sequence in K-theory together with the positive cone of the K_0-groups of the distinguished ideal and quotient. We then apply our results to a class of C*-algebras arising from substitutional shift spaces.Comment: 22 pages, Reordered some sections, an application involving graph algebras is adde

Prescription of physical exercise in Crohn's disease

AbstractBackgroundPhysical exercise may be potentially beneficial for recovering physical condition and improving quality of life in populations suffering from chronic conditions, but little is known about its effects on patients suffering from Crohn's disease.AimsTo provide reasonable and conservative recommendations for exercise regimens that appear clinically safe and feasible in patients suffering from Crohn's disease.MethodsRelevant clinical studies about the effects of physical exercise on Crohn's disease, written in English language and carried out with human subjects were reviewed.ResultsFew relevant clinical studies have evaluated the effects of an exercise intervention on patients experiencing Crohn's disease. There seem to be two main types of physical interventions that should be recommended: aerobic activity and muscular resistance training.ConclusionsSome basic guidelines about how to prescribe physical exercise in Crohn's disease can be provided. However, more research is needed as few studies have been carried out so far

International migration and adverse birth outcomes: role of ethnicity, region of origin and destination

Background: The literature on international migration and birth outcomes shows mixed results. This study examined whether low birth weight (LBW) and preterm birth differed between non-migrants and migrant subgroups, defined by race/ethnicity and world region of origin and destination. Methods: A systematic review and meta-regression analyses were conducted using three-level logistic models to account for the heterogeneity between studies and between subgroups within studies. Results: Twenty-four studies, involving more than 30 million singleton births, met the inclusion criteria. Compared with US-born black women, black migrant women were at lower odds of delivering LBW and preterm birth babies. Hispanic migrants also exhibited lower odds for these outcomes, but Asian and white migrants did not. Sub-Saharan African and Latin-American and Caribbean women were at higher odds of delivering LBW babies in Europe but not in the USA and south-central Asians were at higher odds in both continents, compared with the native-born populations. Conclusions: The association between migration and adverse birth outcomes varies by migrant subgroup and it is sensitive to the definition of the migrant and reference groups

Current partition: Nonequilibrium Green's function Approach

We present a solution to the problem of AC current partition in a multi-probe mesoscopic conductor within the nonequilibrium Green's function formalism. This allows the derivation of dynamic conductance which is appropriate for nonequilibrium situations and which satisfies the current conservation and gauge invariance requirements. This formalism presents a significant generalization to previous theory: (i) there is no limit in the frequency, and (ii) it allows detailed treatments of interactions in the mesoscopic region. The formalism is applied to calculate dynamic conductance of tunneling structures with and without assuming wideband limit.Comment: 4 pages, 3 figure

Financial strain moderates genetic influences on self-rated health: support for diathesis–stress model of gene–environment interplay

Data from the Interplay of Genes and Environment across Multiple Studies (IGEMS) consortium were used to examine predictions of different models of gene-by-environment interaction to understand how genetic variance in self-rated health (SRH) varies at different levels of financial strain. A total of 11,359 individuals from 10 twin studies in Australia, Sweden, and the United States contributed relevant data, including 2,074 monozygotic and 2,623 dizygotic twin pairs. Age ranged from 22 to 98 years, with a mean age of 61.05 (SD = 13.24). A factor model was used to create a harmonized measure of financial strain across studies and items. Twin analyses of genetic and environmental variance for SRH incorporating age, age2, sex, and financial strain moderators indicated significant financial strain moderation of genetic influences on self-rated health. Moderation results did not differ across sex or country. Genetic variance for SRH increased as financial strain increased, matching the predictions of the diathesis–stress and social comparison models for components of variance. Under these models, environmental improvements would be expected to reduce genetically based health disparities