The exterior degree of a pair of finite groups

The exterior degree of a pair of finite groups $(G,N)$, which is a generalization of the exterior degree of finite groups, is the probability for two elements $(g,n)$ in $(G,N)$ such that $g\wedge n=1$. In the present paper, we state some relations between this concept and the relative commutatively degree, capability and the Schur multiplier of a pair of groups.Comment: To appear in Mediterr. J. Mat

Solidification behavior of intensively sheared hypoeutectic Al-Si alloy liquid

The official published version of this article can be found at the link below.The effect of the processing temperature on the microstructural and mechanical properties of Al-Si (hypoeutectic) alloy solidified from intensively sheared liquid metal has been investigated systematically. Intensive shearing gives a significant refinement in grain size and intermetallic particle size. It also is observed that the morphology of intermetallics, defect bands, and microscopic defects in high-pressure die cast components are affected by intensive shearing the liquid metal. We attempt to discuss the possible mechanism for these effects.Funded by the EPSRC

Cluster of Dipolar Coupled Spins as a Quantum Memory Storage

Spin dynamics of a cluster of coupled spins 1/2 can be manipulated to store and process a large amount of information. A new type of dynamic response makes it possible to excite coherent long-living signals, which can be used for exchanging information with a mesoscopic quantum system. An experimental demonstration is given for a system of 19 proton spins of a liquid crystal molecule.Comment: 5 pages, 1 figur

The de Rham homotopy theory and differential graded category

This paper is a generalization of arXiv:0810.0808. We develop the de Rham homotopy theory of not necessarily nilpotent spaces, using closed dg-categories and equivariant dg-algebras. We see these two algebraic objects correspond in a certain way. We prove an equivalence between the homotopy category of schematic homotopy types and a homotopy category of closed dg-categories. We give a description of homotopy invariants of spaces in terms of minimal models. The minimal model in this context behaves much like the Sullivan's minimal model. We also provide some examples. We prove an equivalence between fiberwise rationalizations and closed dg-categories with subsidiary data.Comment: 47 pages. final version. The final publication is available at http://www.springerlink.co

Dimerization of inositol monophosphatase Mycobacterium tuberculosis SuhB is not constitutive, but induced by binding of the activator Mg2+

Background The cell wall of Mycobacterium tuberculosis contains a wide range of phosphatidyl inositol-based glycolipids that play critical structural roles and, in part, govern pathogen-host interactions. Synthesis of phosphatidyl inositol is dependent on free myo-inositol, generated through dephosphorylation of myo-inositol-1-phosphate by inositol monophosphatase (IMPase). Human IMPase, the putative target of lithium therapy, has been studied extensively, but the function of four IMPase-like genes in M. tuberculosis is unclear. Results We determined the crystal structure, to 2.6 Å resolution, of the IMPase M. tuberculosis SuhB in the apo form, and analysed self-assembly by analytical ultracentrifugation. Contrary to the paradigm of constitutive dimerization of IMPases, SuhB is predominantly monomeric in the absence of the physiological activator Mg2+, in spite of a conserved fold and apparent dimerization in the crystal. However, Mg2+ concentrations that result in enzymatic activation of SuhB decisively promote dimerization, with the inhibitor Li+ amplifying the effect of Mg2+, but failing to induce dimerization on its own. Conclusion The correlation of Mg2+-driven enzymatic activity with dimerization suggests that catalytic activity is linked to the dimer form. Current models of lithium inhibition of IMPases posit that Li+ competes for one of three catalytic Mg2+ sites in the active site, stabilized by a mobile loop at the dimer interface. Our data suggest that Mg2+/Li+-induced ordering of this loop may promote dimerization by expanding the dimer interface of SuhB. The dynamic nature of the monomer-dimer equilibrium may also explain the extended concentration range over which Mg2+ maintains SuhB activity

Rho-omega mixing in asymmetric nuclear matter via QCD sum rule approach

We evaluate the operator product expansion (OPE) for a mixed correlator of the isovector and isoscalar vector currents in the background of the nucleon density with intrinsic isospin asymmetry [i.e. excess of neutrons over protons] and match it with its imaginary part, given by resonances and continuum, via the dispersion relation. The leading density-dependent contribution to $\rho-\omega$ mixing is due the scattering term, which turns out to be larger than any density dependent piece in the OPE. We estimate that the asymmetric density of $n_n-n_p \sim 2.5 \times 10^{-2} ~{\rm fm^3}$ induces the amplitude of $\rho-\omega$ mixing, equal in magnitude to the mixing amplitude in vacuum, with the constructive interference for positive and destructive for negative values of $n_n-n_p$. We revisit sum rules for vector meson masses at finite nucleon density to point out the numerical importance of the screening term in the isoscalar channel, which turns out to be one order of magnitude larger than any density-dependent condensates over the Borel window. This changes the conclusions about the density dependence of $m_\omega$, indicating $\sim 40$ MeV increase at nuclear saturation density.Comment: 8 pages, Revte

Generation and Evolution of Spin Entanglement in NRQED

A complete analysis on the generation of spin entanglement from NRQED is presented. The results of entanglement are obtained with relativistic correction to the leading order of (v/c)^2. It is shown that to this order the degree of entanglement of a singlet state does not change under time evolution whereas the triplet state can change.Comment: 8 pages, 1 figure, to appear in Phys. Rev.

A Systematic Review Of The Types And Causes Of Prescribing Errors Generated From Using Computerized Provider Order Entry Systems in Primary and Secondary Care

Objective To understand the different types and causes of prescribing errors associated with computerized provider order entry (CPOE) systems, and recommend improvements in these systems. Materials and Methods We conducted a systematic review of the literature published between January 2004 and June 2015 using three large databases: the Cumulative Index to Nursing and Allied Health Literature, Embase, and Medline. Studies that reported qualitative data about the types and causes of these errors were included. A narrative synthesis of all eligible studies was undertaken. Results A total of 1185 publications were identified, of which 34 were included in the review. We identified 8 key themes associated with CPOE-related prescribing errors: computer screen display, drop-down menus and auto-population, wording, default settings, nonintuitive or inflexible ordering, repeat prescriptions and automated processes, users’ work processes, and clinical decision support systems. Displaying an incomplete list of a patient’s medications on the computer screen often contributed to prescribing errors. Lack of system flexibility resulted in users employing error-prone workarounds, such as the addition of contradictory free-text comments. Users’ misinterpretations of how text was presented in CPOE systems were also linked with the occurrence of prescribing errors. Discussion and Conclusions Human factors design is important to reduce error rates. Drop-down menus should be designed with safeguards to decrease the likelihood of selection errors. Development of more sophisticated clinical decision support, which can perform checks on free-text, may also prevent errors. Further research is needed to ensure that systems minimize error likelihood and meet users’ workflow expectations

The impact of promoting revised UK low-risk drinking guidelines on alcohol consumption: interrupted time series analysis

Background The UK’s Chief Medical Officers revised the UK alcohol drinking guidelines in 2016 to ≤ 14 units per week (1 unit = 10 ml/8 g ethanol) for men and women. Previously, the guideline stated that men should not regularly consume more than 3–4 units per day and women should not regularly consume more than 2–3 units per day. Objective To evaluate the impact of promoting revised UK drinking guidelines on alcohol consumption. Design Interrupted time series analysis of observational data. Setting England, March 2014 to October 2017. Participants A total of 74,388 adults aged ≥ 16 years living in private households in England. Interventions Promotion of revised UK low-risk drinking guidelines. Main outcome measures Primary outcome – alcohol consumption measured by the Alcohol Use Disorders Identification Test – Consumption score. Secondary outcomes – average weekly consumption measured using graduated frequency, monthly alcohol consumption per capita adult (aged ≥ 16 years) derived from taxation data, monthly number of hospitalisations for alcohol poisoning (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision: T51.0, T51.1 and T51.9) and assault (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision: X85–Y09), and further measures of influences on behaviour change. Data sources The Alcohol Toolkit Study, a monthly cross-sectional survey and NHS Digital’s Hospital Episode Statistics. Results The revised drinking guidelines were not subject to large-scale promotion after the initial January 2016 announcement. An analysis of news reports found that mentions of the guidelines were mostly factual, and spiked during January 2016. In December 2015, the modelled average Alcohol Use Disorders Identification Test – Consumption score was 2.719 out of 12.000 and was decreasing by 0.003 each month. After the January 2016 announcement, Alcohol Use Disorders Identification Test – Consumption scores did not decrease significantly (β = 0.001, 95% confidence interval –0.079 to 0.099). However, the trend did change significantly such that scores subsequently increased by 0.005 each month (β = 0.008, 95% confidence interval 0.001 to 0.015). This change is equivalent to 0.5% of the population moving each month from drinking two or three times per week to drinking four or more times per week. Secondary analyses indicated that the change in trend began 6 months before the guideline announcement. The secondary outcome measures showed conflicting results, with no significant changes in consumption measures and no substantial changes in influences on behaviour change, but immediate reductions in hospitalisations of 7.3% for assaults and 15.4% for alcohol poisonings. Limitations The pre-intervention data collection period was only 2 months for influences on behaviour change and the graduated frequency measure. Our conclusions may be generalisable only to scenarios in which guidelines are announced but not promoted. Conclusions The announcement of revised UK low-risk drinking guidelines was not associated with clearly detectable changes in drinking behaviour. Observed reductions in alcohol-related hospitalisations are unlikely to be attributable to the revised guidelines. Promotion of the guidelines may have been prevented by opposition to the revised guidelines from the government's alcohol industry partners or because reduction in alcohol consumption was not a government priority or because practical obstacles prevented independent public health organisations from promoting the guidelines. Additional barriers to the effectiveness of guidelines may include low public understanding and a need for guidelines to engage more with how drinkers respond to and use them in practice. Trial registration Current Controlled Trials ISRCTN15189062. Funding This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 14. See the NIHR Journals Library website for further project information

Effects on alcohol consumption of announcing and implementing revised UK low-risk drinking guidelines : findings from an interrupted time series analysis

Background: In January 2016, the UK announced and began implementing revised guidelines for low-risk drinking of 14 units (112 g) per week for men and women. This was a reduction from the previous guidelines for men of 3–4 units (24–32 g) per day. There was no large-scale promotion of the revised guidelines beyond the initial media announcement. This paper evaluates the effect of announcing the revised guidelines on alcohol consumption among adults in England. Methods: Data come from a monthly repeat cross-sectional survey of approximately 1700 adults living in private households in England collected between March 2014 and October 2017. The primary outcomes are change in level and time trend of participants’ Alcohol Use Disorders Identification Test—Consumption (AUDIT-C) scores. Results: In December 2015, the modelled average AUDIT-C score was 2.719 out of 12 and was decreasing by 0.003 each month. After January 2016, AUDIT-C scores increased immediately but non-significantly to 2.720 (β=0.001, CI −0.079 to 0.099) and the trend changed significantly such that scores subsequently increased by 0.005 each month (β=0.008, CI 0.001 to 0.015), equivalent to 0.5% of the population increasing their AUDIT-C score by 1 point each month. Secondary analyses indicated the change in trend began 7 months before the guideline announcement and that AUDIT-C scores reduced significantly but temporarily for 4 months after the announcement (β=−0.087, CI −0.167 to 0.007). Conclusions: Announcing new UK drinking guidelines did not lead to a substantial or sustained reduction in drinking or a downturn in the long-term trend in alcohol consumption, but there was evidence of a temporary reduction in consumption