94 research outputs found

    Universally Typical Sets for Ergodic Sources of Multidimensional Data

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    We lift important results about universally typical sets, typically sampled sets, and empirical entropy estimation in the theory of samplings of discrete ergodic information sources from the usual one-dimensional discrete-time setting to a multidimensional lattice setting. We use techniques of packings and coverings with multidimensional windows to construct sequences of multidimensional array sets which in the limit build the generated samples of any ergodic source of entropy rate below an h0h_0 with probability one and whose cardinality grows at most at exponential rate h0h_0.Comment: 15 pages, 1 figure. To appear in Kybernetika. This replacement corrects typos and slightly strengthens the main theore

    Laparoscopic incisional hernia repair is feasible and safe after liver transplantation

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    Background: Incisional hernia is a common complication after liver transplantation. The current study evaluated incidence and risk factors for incisional hernia and compared laparoscopic and open hernia repair in terms of feasibility and outcome. Methods: A cohort of 225 patients was prospectively investigated. The median follow-up period was 61months (range, 6-186months). The study cohort had 31 patients who underwent open repair and 13 who underwent laparoscopic repair. Results: Incisional hernia, found in 57 patients (25%), had occurred after a median of 17months (range, 5-138months). The significant risk factors were male gender (p = 0.001) and body mass index (BMI) greater than 25kg/m2 (p = 0.002). A trend toward a lower recurrence rate (15% vs 35%; p = 0.28) and fewer surgical complications (15% vs 19%; p = 0.99) was found in the laparoscopic group. Conclusions: Incisional hernia is a frequent complication after liver transplantation. Associated risk factors are male gender and a BMI greater than 25kg/m2. Laparoscopic hernia repair for such patients is feasible and saf

    Intraperitoneal Mesh Implantation for Fascial Dehiscence and Open Abdomen

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    Background: Postoperative fascial dehiscence and open abdomen are severe postoperative complications and are associated with surgical site infections, fistula, and hernia formation at long-term follow-up. This study was designed to investigate whether intraperitoneal implantation of a composite prosthetic mesh is feasible and safe. Methods: A total of 114 patients with postoperative fascial dehiscence and open abdomen who had undergone surgery between 2001 and 2009 were analyzed retrospectively. Contaminated (wound class 3) or dirty wounds (wound class 4) were present in all patients. A polypropylene-based composite mesh was implanted intraperitoneally in 51 patients, and in 63 patients the abdominal wall was closed without mesh implantation. The primary endpoint was incidence of incisional hernia, and the incidence of enterocutaneous fistula was a secondary endpoint. Results: The incidence of enterocutaneous fistulas after wound closure post-fascial dehiscence (13% vs. 6% without and with mesh, respectively) or post-open abdomen (22% vs. 28% without and with mesh, respectively) was not significantly different. The incidence of incisional hernia was significantly lower with mesh implantation compared with no-mesh implantation in both contaminated (4% vs. 28%; p=0.025) and dirty abdominal cavities (5% vs. 34%; p=0.01). Conclusions: Intra-abdominal contamination is not a contraindication for intra-abdominal mesh implantation. The incidence of enterocutaneous fistula is not elevated despite the presence of contamination. The rate of incisional hernias is significantly reduced after intraperitoneal mesh implantation for postoperative fascial dehiscence or open abdome

    The impact of the coronary collateral circulation on mortality: a meta-analysis

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    Aims The coronary collateral circulation as an alternative source of blood supply has shown benefits regarding several clinical endpoints in patients with myocardial infarction (MI) such as infarct size and left ventricular remodelling. However, its impact on hard endpoints such as mortality and its impact in patients with stable coronary artery disease (CAD) is more controversial. The purpose of this systematic review and meta-analysis was to explore the impact of collateral circulation on all-cause mortality. Methods and results We searched MEDLINE, EMBASE, ISI Web of Science (2001 to 25 April 2011), and conference proceedings for studies evaluating the effect of coronary collaterals on mortality. Random-effect models were used to calculate summary risk ratios (RR). A total of 12 studies enrolling 6529 participants were included in this analysis. Patients with high collateralization showed a reduced mortality compared with those with low collateralization [RR 0.64 (95% confidence interval 0.45-0.91); P= 0.012]. The RR for ‘high collateralization' in patients with stable CAD was 0.59 [0.39-0.89], P= 0.012, in patients with subacute MI it was 0.53 [0.15-1.92]; P= 0.335, and for patients with acute MI it was 0.63 [0.29-1.39]; P= 0.257. Conclusions In patients with CAD, the coronary collateralization has a relevant protective effect. Patients with a high collateralization have a 36% reduced mortality risk compared with patients with low collateralizatio

    Intraperitoneal mesh implantation for fascial dehiscence and open abdomen

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    Postoperative fascial dehiscence and open abdomen are severe postoperative complications and are associated with surgical site infections, fistula, and hernia formation at long-term follow-up. This study was designed to investigate whether intraperitoneal implantation of a composite prosthetic mesh is feasible and safe

    Language change for the worse

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    Many theories hold that language change, at least on a local level, is driven by a need for improvement. The present volume explores to what extent this assumption holds true, and whether there is a particular type of language change that we dub language change for the worse, i.e., change with a worsening effect that cannot be explained away as a side-effect of improvement in some other area of the linguistic system. The chapters of the volume, written by leading junior and senior scholars, combine expertise in diachronic and historical linguistics, typology, and formal modelling. They focus on different aspects of grammar (phonology, morphosyntax, semantics) in a variety of language families (Germanic, Romance, Austronesian, Bantu, Jê-Kaingang, Wu Chinese, Greek, Albanian, Altaic, Indo-Aryan, and languages of the Caucasus). The volume contributes to ongoing theoretical debates and discussions between linguists with different theoretical orientations

    Coronary collaterals and risk for restenosis after percutaneous coronary interventions: a meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>The benefit of the coronary collateral circulation (natural bypass network) on survival is well established. However, data derived from smaller studies indicates that coronary collaterals may increase the risk for restenosis after percutaneous coronary interventions. The purpose of this systematic review and meta-analysis of observational studies was to explore the impact of the collateral circulation on the risk for restenosis.</p> <p>Methods</p> <p>We searched the MEDLINE, EMBASE and ISI Web of Science databases (2001 to 15 July 2011). Random effects models were used to calculate summary risk ratios (RR) for restenosis. The primary endpoint was angiographic restenosis > 50%.</p> <p>Results</p> <p>A total of 7 studies enrolling 1,425 subjects were integrated in this analysis. On average across studies, the presence of a good collateralization was predictive for restenosis (risk ratio (RR) 1.40 (95% CI 1.09 to 1.80); <it>P </it>= 0.009). This risk ratio was consistent in the subgroup analyses where collateralization was assessed with intracoronary pressure measurements (RR 1.37 (95% CI 1.03 to 1.83); <it>P </it>= 0.038) versus visual assessment (RR 1.41 (95% CI 1.00 to 1.99); <it>P </it>= 0.049). For the subgroup of patients with stable coronary artery disease (CAD), the RR for restenosis with 'good collaterals' was 1.64 (95% CI 1.14 to 2.35) compared to 'poor collaterals' (<it>P </it>= 0.008). For patients with acute myocardial infarction, however, the RR for restenosis with 'good collateralization' was only 1.23 (95% CI 0.89 to 1.69); <it>P </it>= 0.212.</p> <p>Conclusions</p> <p>The risk of restenosis after percutaneous coronary intervention (PCI) is increased in patients with good coronary collateralization. Assessment of the coronary collateral circulation before PCI may be useful for risk stratification and for the choice of antiproliferative measures (drug-eluting stent instead bare-metal stent, cilostazol).</p

    Tuning inflammation in tuberculosis: the role of decoy receptors

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    Decoy receptors are "silent scavengers" of CC chemokines and cytokines, which play a key role in damping inflammation and tissue damage. In this review we discuss on recent findings demonstrating that these receptors set the balance between antimicrobial resistance, immune activation and inflammatory response in Mycobacterium tuberculosis infection

    Simian Immunodeficiency Virus Infection of Chimpanzees (Pan troglodytes) Shares Features of Both Pathogenic and Non-pathogenic Lentiviral Infections.

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    The virus-host relationship in simian immunodeficiency virus (SIV) infected chimpanzees is thought to be different from that found in other SIV infected African primates. However, studies of captive SIVcpz infected chimpanzees are limited. Previously, the natural SIVcpz infection of one chimpanzee, and the experimental infection of six chimpanzees was reported, with limited follow-up. Here, we present a long-term study of these seven animals, with a retrospective re-examination of the early stages of infection. The only clinical signs consistent with AIDS or AIDS associated disease was thrombocytopenia in two cases, associated with the development of anti-platelet antibodies. However, compared to uninfected and HIV-1 infected animals, SIVcpz infected animals had significantly lower levels of peripheral blood CD4+ T-cells. Despite this, levels of T-cell activation in chronic infection were not significantly elevated. In addition, while plasma levels of β2 microglobulin, neopterin and soluble TNF-related apoptosis inducing ligand (sTRAIL) were elevated in acute infection, these markers returned to near-normal levels in chronic infection, reminiscent of immune activation patterns in 'natural host' species. Furthermore, plasma soluble CD14 was not elevated in chronic infection. However, examination of the secondary lymphoid environment revealed persistent changes to the lymphoid structure, including follicular hyperplasia in SIVcpz infected animals. In addition, both SIV and HIV-1 infected chimpanzees showed increased levels of deposition of collagen and increased levels of Mx1 expression in the T-cell zones of the lymph node. The outcome of SIVcpz infection of captive chimpanzees therefore shares features of both non-pathogenic and pathogenic lentivirus infections.This work was supported by the Biotechnology and Biological Sciences Research Council and by the Wellcome Trust.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.ppat.100514
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