25 research outputs found

    A Kadison Kastler row metric and intermediate subalgebras

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    In this paper, we introduce a row version of Kadison and Kastler's metric on the set of C*-subalgebras of B(H). By showing C*-algebras have row length (in the sense of Pisier) of at most 2 we show that the row metric is equivalent to the original Kadison–Kastler metric. Ino and Watatani have recently proved that in certain circumstances sufficiently close intermediate C*-algebras occur as small unitary perturbations. By adjusting their arguments to work with the row metric we are able to obtain universal constants independent of inclusions

    Topics regarding close operator algebras

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    In this thesis we focus on two topics. For the first we introduce a row version of Kadison and Kastler's metric on the set of C*-subalgebras of B(H). By showing C*-algebras have row length (in the sense of Pisier) of at most two we show that the row metric is equivalent to the original Kadison- Kastler metric. We then use this result to obtain universal constants for a recent perturbation result of Ino and Watatani, which states that succiently close intermediate subalgebras must occur as small unitary perturbations, by removing the dependence on the structure of inclusion. Roydor has recently proved that injective von Neumann algebras are Kadison-Kastler stable in a non-self adjoint sense, extending seminal results of Christensen. We prove a one-sided version, showing that an injective von Neumann algebra which is nearly contained in a weak*-closed non-self adjoint algebra can be embedded by a similarity close to the natural inclusion map. This theorem can then be used to extend results of Cameron et al. by demonstrating Kadison-Kastler stability of certain crossed products in the non self-adjoint setting. These crossed products can be chosen to be non-amenable

    A Kadison–Kastler row metric and intermediate subalgebras

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    How Could Minority and Women's Rights be Protected in a United Ireland?

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    This is a report of a seminar held at Ulster University by the Equality Coalition and Transitional Justice Institute, supported by the Gender, Justice and Security Hub

    Introductory programming: a systematic literature review

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    As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Incorporating Geographical Scale and Multiple Environmental Factors to Delineate the Breeding Distribution of Sea Turtles

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    Temperature is often used to infer how climate influences wildlife distributions; yet, other parameters also contribute, separately and combined, with effects varying across geographical scales. Here, we used an unoccupied aircraft system to explore how environmental parameters affect the regional distribution of the terrestrial and marine breeding habitats of threatened loggerhead sea turtles (Caretta caretta). Surveys spanned four years and ~620 km coastline of western Greece, encompassing low (<10 nests/km) to high (100–500 nests/km) density nesting areas. We recorded 2395 tracks left by turtles on beaches and 1928 turtles occupying waters adjacent to these beaches. Variation in beach track and inwater turtle densities was explained by temperature, offshore prevailing wind, and physical marine and terrestrial factors combined. The highest beach-track densities (400 tracks/km) occurred on beaches with steep slopes and higher sand temperatures, sheltered from prevailing offshore winds. The highest inwater turtle densities (270 turtles/km) occurred over submerged sandbanks, with warmer sea temperatures associated with offshore wind. Most turtles (90%) occurred over nearshore submerged sandbanks within 10 km of beaches supporting the highest track densities, showing the strong linkage between optimal marine and terrestrial environments for breeding. Our findings demonstrate the utility of UASs in surveying marine megafauna and environmental data at large scales and the importance of integrating multiple factors in climate change models to predict species distributions

    Uporaba krivulje plastičnega tečenja v numeričnih simulacijah

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    V prispevku je obravnavano določevanje krivulje plastičnega tečenja jeklene pločevine pri velikih deformacijah. Uporabljena sta dva računska postopka, obema pa kot eksperimentalna osnova služi klasični natezni preizkus. Pri prvem postopku krivuljo plastičnega tečenja aproksimiramo s pomočjo t.i. Ludvikovega zakona ter tako dobljeno krivuljo se ekstrapoliramo na območje velikih deformacij. Drugi postopek temelji na inverzni identifikaciji, kjer krivuljo plastičnega tečenja pri velikih deformacijah okarakteriziramo na osnovi meritev nateznega preizkusa po nastanku lokalne zožitve na nateznem preizkušancu. Značilnosti obeh postopkov so obrazložene na primerih računalniskih simulacij nateznega preizkusa in globokega vleka. Že v primeru simulacije nateznega preizkusa metoda inverzne identifikacije prekaša metodo aproksimacije z Ludvikovim zakonom, primer simulacije globokega vleka pa nazorno prikaže, kako uporaba neprimerne krivulje plastičnega tečenja vodi do napačnih sklepov in napovedi.A comparison of two approaches used in the yield curve characterization of thesame material is given in the paper. The first approach is commonly used Ludwig\u27s law with the extension over large strains based on the pre-necking response of a tensile test specimen, whereas the second approach is inverse identification which is based on the post-necking behaviour of the same tensile test specimen. Features of both approaches are examined in the tensile test and deep drawing simulations. In the tensile test simulation the inverse identification method proved to be superior over Ludwig\u27s law. The deep drawing simulation demonstrates how inappropriate yield curve usage leads to wrong predictions
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