Tarski monoids: Matui's spatial realization theorem

We introduce a class of inverse monoids, called Tarski monoids, that can be regarded as non-commutative generalizations of the unique countable, atomless Boolean algebra. These inverse monoids are related to a class of etale topological groupoids under a non-commutative generalization of classical Stone duality and, significantly, they arise naturally in the theory of dynamical systems as developed by Matui. We are thereby able to reinterpret a theorem of Matui on a class of \'etale groupoids as an equivalent theorem about a class of Tarski monoids: two simple Tarski monoids are isomorphic if and only if their groups of units are isomorphic. The inverse monoids in question may also be viewed as countably infinite generalizations of finite symmetric inverse monoids. Their groups of units therefore generalize the finite symmetric groups and include amongst their number the classical Thompson groups.Comment: arXiv admin note: text overlap with arXiv:1407.147

\'Etale groupoids and Steinberg algebras, a concise introduction

We give a concise introduction to (discrete) algebras arising from \'etale groupoids, (aka Steinberg algebras) and describe their close relationship with groupoid C*-algebras. Their connection to partial group rings via inverse semigroups also explored

Tiling groupoids and Bratteli diagrams

Let T be an aperiodic and repetitive tiling of R^d with finite local complexity. Let O be its tiling space with canonical transversal X. The tiling equivalence relation R_X is the set of pairs of tilings in X which are translates of each others, with a certain (etale) topology. In this paper R_X is reconstructed as a generalized "tail equivalence" on a Bratteli diagram, with its standard AF-relation as a subequivalence relation. Using a generalization of the Anderson-Putnam complex, O is identified with the inverse limit of a sequence of finite CW-complexes. A Bratteli diagram B is built from this sequence, and its set of infinite paths dB is homeomorphic to X. The diagram B is endowed with a horizontal structure: additional edges that encode the adjacencies of patches in T. This allows to define an etale equivalence relation R_B on dB which is homeomorphic to R_X, and contains the AF-relation of "tail equivalence".Comment: 34 pages, 4 figure

Relative commutants of strongly self-absorbing C*-algebras

The relative commutant $A'\cap A^{\mathcal{U}}$ of a strongly self-absorbing algebra $A$ is indistinguishable from its ultrapower $A^{\mathcal{U}}$. This applies both to the case when $A$ is the hyperfinite II$_1$ factor and to the case when it is a strongly self-absorbing C*-algebra. In the latter case we prove analogous results for $\ell_\infty(A)/c_0(A)$ and reduced powers corresponding to other filters on $\bf N$. Examples of algebras with approximately inner flip and approximately inner half-flip are provided, showing the optimality of our results. We also prove that strongly self-absorbing algebras are smoothly classifiable, unlike the algebras with approximately inner half-flip.Comment: Some minor correction

The 200 MeV Bremsstrahlung Tagged Photon Beam at LNS-Sendai(I. Nuclear Physics)

We describe the 200-MeV bremsstrahlung photon tagging system, which was installed in the experimental Hall-1 at the Laboratory of Nuclear Science, Tohoku University. This system produces tagged photons from high duty electron beams supplied by Stretcher Booster Ring. The tagged photon energies are over a range from 20% to 80% of the incident electron energy. We carried out commissioning to examine the performance of the tagged photon beams produced by the 198 MeV electron beam. We demonstrated that the tagged photons can be employed for photonuclear reaction experiments with a momentum resolution Δp/p～1% at the tagged photon intensity I≤5×10^6

The use of electronic alerts in primary care computer systems to identify the excessive prescription of short-acting beta2-agonists for people with asthma: a systematic review.

Computers are increasingly used to improve prescribing decisions in the management of long-term conditions however the effects on asthma prescribing remain unclear. We aimed to synthesise the evidence for the use of computerised alerts that identify excessive prescribing of short-acting beta2-agonists (SABAs) to improve asthma management for people with asthma. MEDLINE, CINAHL, Embase, Cochrane and Scopus databases (1990-2016) were searched for randomised controlled trials using electronic alerts to identify excessive prescribing of SABAs for people with asthma in primary care. Inclusion eligibility, quality appraisal (Cochrane risk of bias tool) and data extraction were performed by two independent reviewers. Findings were synthesised narratively. A total of 2035 articles were screened and four trials were eligible. Three studies had low risk of bias: one reported a positive effect on our primary outcome of interest, excessive SABA prescribing; another reported positive effects on the ratio of inhaled corticosteroid (ICS)-SABA prescribing, and asthma control; a third reported no effect on outcomes of interest. One study at high risk of bias reported a reduction in exacerbations and primary care consultations. There is some evidence that electronic alerts reduce excessive prescribing of SABAs, when delivered as part of a multicomponent intervention in an integrated health care system. However due to the variation in health care systems, intervention design and outcomes measured, further research is required to establish optimal design of alerting and intervening systems.The authors wish to thank Asthma UK and Queen Mary University London for funding this work as part of a PhD studentship carried out by S.M. A.D.S. is funded by a NIHR Academic Clinical Lectureship. A.B. is a National Institute for Health Research (NIHR) Senior Investigator and additionally was supported by the NIHR Respiratory Disease Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London. M.T. is supported by the NIHR Collaboration for Leadership in Applied Health Research and Care (CLAHRC) Wessex, NIHR School of Primary Care Research and NIHR Southampton Biomedical Research Centre. C.G. is supported by the NIHR CLAHRC North Thames at Bart’s Health NHS Trust. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. This work is funded by Asthma UK and Queen Mary University of London

The establishment and development of neurosurgery services in Papua New Guinea

BACKGROUND: Papua New Guinea (PNG) is a developing Pacific Nation of 7.3 million people. Although neurosurgery training was introduced to PNG in the year 2000, it was in 2003 that a neurosurgery service was established. Prior to this time, neurosurgery in PNG was performed by general surgeons, with some assistance from visiting Australian neurosurgeons. Neurosurgical training was introduced to PNG in 2000. The model involved a further 3 years of training for a surgeon who had already completed 4 years of general surgical training. We aim to review the output, outcomes and impact achieved by training the first national neurosurgeon. METHODS: The data on activity (output) and outcomes were collected prospectively from 2003-2012. Ongoing mentoring and continuing professional development were provided through annual neurosurgical visits from Australia. There were serious limitations in the provision of equipment, with a lack of computerized tomographic or MR imaging, and adjuvant oncological services. RESULTS: There were 1618 neurosurgery admissions, 1020 neurosurgical procedures with a 5.74 % overall mortality. Seventy percent of cases presented as emergencies. There were improved outcomes, particularly for head injuries, whilst hydrocephalus was managed with an acceptable morbidity and revision rate. CONCLUSIONS: The training of a neurosurgeon resulted in PNG patients receiving a better range of surgical services, with a lower mortality. The outcomes able to be delivered were limited by late presentations of patients and lack of resources including imaging. These themes are familiar to all low- and middle-income countries (LMICs) and this may serve as a model for other LMIC neurosurgical services to adopt as they consider whether to establish and develop neurosurgical and other sub-specialist surgical services

A pregnant virgin with microperforate hymen: A noteworthy obstetric case

A Pinhead-sized hymenal opening can permit spontaneous pregnancy. A 26-year-old primigravida presented to our institution for antenatal care in the late 2nd trimester. She reported to have conceived through contact of semen with her vulva, but had never had penetrative vaginal sex. On subsequent follow up, a decision to have an elective caesarean at 39 weeks was made. We report this example because management of such cases can be challenging especially if a timely diagnosis is not made due to lack of awareness and the patient presents when pregnant.Keywords: Pregnant virgin, Elective caesarean, Microperforate hymen, Dilatio