Bell inequalities stronger than the CHSH inequality for 3-level isotropic states

We show that some two-party Bell inequalities with two-valued observables are stronger than the CHSH inequality for 3 \otimes 3 isotropic states in the sense that they are violated by some isotropic states in the 3 \otimes 3 system that do not violate the CHSH inequality. These Bell inequalities are obtained by applying triangular elimination to the list of known facet inequalities of the cut polytope on nine points. This gives a partial solution to an open problem posed by Collins and Gisin. The results of numerical optimization suggest that they are candidates for being stronger than the I_3322 Bell inequality for 3 \otimes 3 isotropic states. On the other hand, we found no Bell inequalities stronger than the CHSH inequality for 2 \otimes 2 isotropic states. In addition, we illustrate an inclusion relation among some Bell inequalities derived by triangular elimination.Comment: 9 pages, 1 figure. v2: organization improved; less references to the cut polytope to make the main results clear; references added; typos corrected; typesetting style change

The Super-Cooling Agent Icilin Reveals a Mechanism of Coincidence Detection by a Temperature-Sensitive TRP Channel

AbstractTRPM8, a member of the transient receptor potential family of ion channels, depolarizes somatosensory neurons in response to cold. TRPM8 is also activated by the cooling agents menthol and icilin. When exposed to menthol or cold, TRPM8 behaves like many ligand-gated channels, exhibiting rapid activation followed by moderate Ca2+-dependent adaptation. In contrast, icilin activates TRPM8 with extremely variable latency followed by extensive desensitization, provided that calcium is present. Here, we show that, to achieve full efficacy, icilin requires simultaneous elevation of cytosolic Ca2+, either via permeation through TRPM8 channels or by release from intracellular stores. Thus, two stimuli must be paired to elicit full channel activation, illustrating the potential for coincidence detection by TRP channels. Determinants of icilin sensitivity map to a region of TRPM8 that corresponds to the capsaicin binding site on the noxious heat receptor TRPV1, suggesting a conserved molecular logic for gating of these thermosensitive channels by chemical agonists

Using MOST to reveal the secrets of the mischievous Wolf-Rayet binary CV Ser

The WR binary CV Serpentis (= WR113, WC8d + O8-9IV) has been a source of mystery since it was shown that its atmospheric eclipses change with time over decades, in addition to its sporadic dust production. The first high-precision time-dependent photometric observations obtained with the MOST space telescope in 2009 show two consecutive eclipses over the 29d orbit, with varying depths. A subsequent MOST run in 2010 showed a seemingly asymmetric eclipse profile. In order to help make sense of these observations, parallel optical spectroscopy was obtained from the Mont Megantic Observatory (2009, 2010) and from the Dominion Astrophysical Observatory (2009). Assuming these depth variations are entirely due to electron scattering in a beta-law wind, an unprecedented 62% increase in mass-loss rate is observed over one orbital period. Alternatively, no change in mass-loss rate would be required if a relatively small fraction of the carbon ions in the wind globally recombined and coaggulated to form carbon dust grains. However, it remains a mystery as to how this could occur. There also seems to be evidence for the presence of corotating interaction regions (CIR) in the WR wind: a CIR-like signature is found in the light curves, implying a potential rotation period for the WR star of 1.6 d. Finally, a new circular orbit is derived, along with constraints for the wind collision.Comment: 11 pages, 11 figures, 5 table

Cluster-randomized study of intermittent preventive treatment for malaria in infants (IPTi) in southern Tanzania: evaluation of impact on survival.

BACKGROUND\ud \ud Intermittent Preventive Treatment for malaria control in infants (IPTi) consists of the administration of a treatment dose of an anti-malarial drug, usually sulphadoxine-pyrimethamine, at scheduled intervals, regardless of the presence of Plasmodium falciparum infection. A pooled analysis of individually randomized trials reported that IPTi reduced clinical episodes by 30%. This study evaluated the effect of IPTi on child survival in the context of a five-district implementation project in southern Tanzania. [Trial registration: clinical trials.gov NCT00152204].\ud \ud METHODS\ud \ud After baseline household and health facility surveys in 2004, five districts comprising 24 divisions were randomly assigned either to receive IPTi (n = 12) or not (n = 12). Implementation started in March 2005, led by routine health services with support from the research team. In 2007, a large household survey was undertaken to assess the impact of IPTi on survival in infants aged two-11 months through birth history interviews with all women aged 13-49 years. The analysis is based on an "intention-to-treat" ecological design, with survival outcomes analysed according to the cluster in which the mothers lived.\ud \ud RESULTS\ud \ud Survival in infants aged two-11 months was comparable in IPTi and comparison areas at baseline. In intervention areas in 2007, 48% of children aged 12-23 months had documented evidence of receiving three doses of IPTi, compared to 2% in comparison areas (P < 0.0001). Over the three years of the study there was a marked improvement in survival in both groups. Between 2001-4 and 2005-7, mortality rates in two-11 month olds fell from 34.1 to 23.6 per 1,000 person-years in intervention areas and from 32.3 to 20.7 in comparison areas. In 2007, divisions implementing IPTi had a 14% (95% CI -12%, 49%) higher mortality rate in two-11 month olds in comparison with non-implementing divisions (P = 0.31).\ud \ud CONCLUSION\ud \ud The lack of evidence of an effect of IPTi on survival could be a false negative result due to a lack of power or imbalance of unmeasured confounders. Alternatively, there could be no mortality impact of IPTi due to low coverage, late administration, drug resistance, decreased malaria transmission or improvements in vector control and case management. This study raises important questions for programme evaluation design

Hospital Performance Measures and Quality of Care

Increasingly, quality improvement initiatives emphasize public reporting of hospital performance measures, to encourage providers to improve, to help consumers pick providers, and to determine provider payments. Although these measures are based on compliance with well established processes of care, it is unknown whether quality measured in this way is correlated with, or predictive of, clinical outcomes. This Issue Brief summarizes studies that examine and quantify the relationship between frequently used measures of hospital performance and hospital mortality

A stable quasi-periodic 4.18 d oscillation and mysterious occultations in the 2011 MOST light curve of TWHya

We present an analysis of the 2011 photometric observations of TW Hya by the MOST satellite; this is the fourth continuous series of this type. The large-scale light variations are dominated by a strong, quasi-periodic 4.18 d oscillation with superimposed, apparently chaotic flaring activity; the former is most likely produced by stellar rotation with one large hot spot created by a stable accretion funnel in the stable regime of accretion while the latter may be produced by small hot spots, created at moderate latitudes by unstable accretion tongues. A new, previously unnoticed feature is a series of semi-periodic, well defined brightness dips of unknown nature of which 19 were observed during 43 days of our nearly-continuous observations. Re-analysis of the 2009 MOST light curve revealed the presence of 3 similar dips. On the basis of recent theoretical results, we tentatively conclude that the dips may represent occultations of the small hot spots created by unstable accretion tongues by hypothetical optically thick clumps.Comment: Printed in MNRA

Coulomb and Liquid Dimer Models in Three Dimensions

We study classical hard-core dimer models on three-dimensional lattices using analytical approaches and Monte Carlo simulations. On the bipartite cubic lattice, a local gauge field generalization of the height representation used on the square lattice predicts that the dimers are in a critical Coulomb phase with algebraic, dipolar, correlations, in excellent agreement with our large-scale Monte Carlo simulations. The non-bipartite FCC and Fisher lattices lack such a representation, and we find that these models have both confined and exponentially deconfined but no critical phases. We conjecture that extended critical phases are realized only on bipartite lattices, even in higher dimensions.Comment: 4 pages with corrections and update

Photometric variability in FU Ori and Z CMa as observed by MOST

Photometric observations obtained by the MOST satellite were used to characterize optical small scale variability of the young stars FU Ori and Z CMa. Wavelet analysis for FU Ori reveals the possible existence of several 2-9 d quasi-periodic features occurring nearly simultaneously; they may be interpreted as plasma parcels or other localized disc heterogeneities revolving at different Keplerian radii in the accretion disc. Their periods may shorten slowly which may be due to spiralling in of individual parcels toward the inner disc radius, estimated at 4.8+/-0.2 R_sun. Analysis of additional multicolour data confirms the previously obtained relation between variations in the B-V colour index and the V magnitude. In contrast to the FU Ori results, the oscillation spectrum of Z CMa does not reveal any periodicities with the wavelet spectrum possibly dominated by outburst of the Herbig Be component.Comment: Accepted by MNRA

Indirect evidence for stimulation of nitric oxide release by tumour necrosis factor-α in human veins in vivo

Objectives: The detrimental haemodynamic changes observed in septicaemia are generalised vasodilation, arterial hypotension, and hyporesponsiveness to vasopressor compounds, all of which could be explained by the release of an endogenous vasodilator. Experimental and clinical evidence suggests that tumour necrosis factor-α (TNF) induces the expression of vascular nitric oxide (NO) synthase within hours and that NO released from smooth muscle cells could be involved in the pathogenesis of septic shock. The aim of this study was to investigate the role of NO in the vascular effects of TNF. Methods: Using the dorsal hand vein compliance technique, the effect of the NO synthase inhibitor L-NG-monomethyl-arginine (L-NMMA) on α1-adrenergic responsiveness (phenylephrine 1.25-8000 ng/min) was studied after prolonged local venous infusion of TNF (8.7 μg in 5 h) in 9 volunteers and in 6 volunteers without previous cytokine exposure. Results: Mean (±s.e.) maximum phenylephrine constriction (Emax) was 73 ± 6% and log dose-rates exerting 50% of Emax (log ED50) were 3.2 ± 0.09 (geometric mean: 1535 ng/min). Local co-administration of L-NMMA at a dose sufficiently high to block NO formation (3.4 μmol/min) increased venous sensitivity to phenylephrine threefold (log ED50 2.8 ± 0.1, P < 0.015; geometric mean: 574 ng/min) whereas Emax was similar (73 ± 5%). In the controls the phenylephrine dose-response relationship remained unaffected by simultaneous administration of L-NMMA. Conclusions: As no basal release of NO occurs in hand veins without previous exposure to TNF these results provide direct evidence for induction of NO formation in the human vasculature and consecutive resistance to α-adrenergic venoconstriction. NO might, therefore, be a key mediator of haemodynamic impairment in humans under conditions with known elevations of circulating TNF, such as a septic shoc