272 research outputs found

    Operative strategy for fistula-in-ano without division of the anal sphincter

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    We would like to thank Mr ER MacDonald for his contribution in data collection during the early years of the study. The material in this paper was presented as a poster at the annual meeting of the American Society of Colon and Rectal Surgeons held in Vancouver, Canada, May 2011.Peer reviewedPublisher PD

    Local majority dynamics on preferential attachment graphs

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    Suppose in a graph GG vertices can be either red or blue. Let kk be odd. At each time step, each vertex vv in GG polls kk random neighbours and takes the majority colour. If it doesn't have kk neighbours, it simply polls all of them, or all less one if the degree of vv is even. We study this protocol on the preferential attachment model of Albert and Barab\'asi, which gives rise to a degree distribution that has roughly power-law P(x)1x3P(x) \sim \frac{1}{x^{3}}, as well as generalisations which give exponents larger than 33. The setting is as follows: Initially each vertex of GG is red independently with probability α<12\alpha < \frac{1}{2}, and is otherwise blue. We show that if α\alpha is sufficiently biased away from 12\frac{1}{2}, then with high probability, consensus is reached on the initial global majority within O(logdlogdt)O(\log_d \log_d t) steps. Here tt is the number of vertices and d5d \geq 5 is the minimum of kk and mm (or m1m-1 if mm is even), mm being the number of edges each new vertex adds in the preferential attachment generative process. Additionally, our analysis reduces the required bias of α\alpha for graphs of a given degree sequence studied by the first author (which includes, e.g., random regular graphs)

    Experience matters: comparing novice and expert ratings of non-technical skills using the NOTSS system

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    Abstract There is growing evidence that non-technical skills (NTS) are related to surgical outcomes and patient safety. The aim of this study was to further evaluate a behaviour rating system (NOTSS: Non-Technical Skills for Surgeons) which can be used for workplace assessment of the cognitive and social skills which are essential components of NTS. A novice group composed of consultant surgeons (n = 44) from five Scottish hospitals attended one of six experimental sessions and were trained to use the NOTSS system. They then used NOTSS to rate surgeons&apos; behaviors in six simulated scenarios filmed in the operating room. The behaviours demonstrated in each scenario were compared to expert ratings to determine accuracy. The mode rating from the novice group (who received a short training session in behaviour assessment) was the same as the expert group in 50% of ratings. Where there was disagreement, novice raters tended to provide lower ratings than the experts. Novice raters require significant training in this emerging area of competence in order to accurately rate nontechnical skills

    Dynamics on expanding spaces: modeling the emergence of novelties

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    Novelties are part of our daily lives. We constantly adopt new technologies, conceive new ideas, meet new people, experiment with new situations. Occasionally, we as individuals, in a complicated cognitive and sometimes fortuitous process, come up with something that is not only new to us, but to our entire society so that what is a personal novelty can turn into an innovation at a global level. Innovations occur throughout social, biological and technological systems and, though we perceive them as a very natural ingredient of our human experience, little is known about the processes determining their emergence. Still the statistical occurrence of innovations shows striking regularities that represent a starting point to get a deeper insight in the whole phenomenology. This paper represents a small step in that direction, focusing on reviewing the scientific attempts to effectively model the emergence of the new and its regularities, with an emphasis on more recent contributions: from the plain Simon's model tracing back to the 1950s, to the newest model of Polya's urn with triggering of one novelty by another. What seems to be key in the successful modelling schemes proposed so far is the idea of looking at evolution as a path in a complex space, physical, conceptual, biological, technological, whose structure and topology get continuously reshaped and expanded by the occurrence of the new. Mathematically it is very interesting to look at the consequences of the interplay between the "actual" and the "possible" and this is the aim of this short review.Comment: 25 pages, 10 figure

    The prognostic value of the tertiary lymphoid structure in gastrointestinal cancers

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    BackgroundNumerous studies and research papers have provided evidence suggesting that tertiary lymphoid structures (TLS) play a crucial role in combating and suppressing tumor growth and progression. Despite the wealth of information on the significance of TLS in various types of cancer, their prognostic value in gastrointestinal (GI) cancers remains uncertain. Therefore, this meta-analysis investigated the prognostic value of TLS in GI cancers.MethodsWe searched Web of science, Pubmed, Embase and Cochrane Library for studies that met the requirements as of May 1, 2023, and the hazard ratio (HR) and the corresponding 95% confidence interval (CI) were included in the analysis. The bioinformatics analysis results based on the TCGA database are used to supplement our research.ResultsThe meta-analysis included 32 studies involving 5778 patients. The results of comprehensive analysis showed that TLS-High is associated with prolonged OS (HR=0.525,95%CI:0.447-0.616 (P &lt; 0.001), RFS (HR=0.546,95%CI:0.461-0.647, P &lt; 0.001), DFS (HR=0.519,95%CI:0.417-0.646, P &lt; 0.001) and PFS (HR=0.588,95%CI:0.406-0.852, P=0.005) in GI cancer. Among the patients who received immunotherapy, TLS-High is associated with significantly prolonged OS (HR=0.475, 95%CI:0.282-0.799, P=0.005) and PFS(HR=0.576, 95%CI:0.381-0.871, P=0.009). It is worth noting that subgroup analysis showed that there was no significant relationship between TLS and OS(HR=0.775, 95%CI:0.570-1.053,P=0.103) in CRC. And when Present is used as the cut-off criteria of TLS, there is no significant correlation between TLS and OS (HR=0.850, 95%CI:0.721-1.002, P=0.053)in HCC.ConclusionTLS is a significant predictor of the prognosis of GI cancers and has the potential to become a prognostic biomarker of immunotherapy-related patients.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42023443562

    Modeling the scaling properties of human mobility

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    While the fat tailed jump size and the waiting time distributions characterizing individual human trajectories strongly suggest the relevance of the continuous time random walk (CTRW) models of human mobility, no one seriously believes that human traces are truly random. Given the importance of human mobility, from epidemic modeling to traffic prediction and urban planning, we need quantitative models that can account for the statistical characteristics of individual human trajectories. Here we use empirical data on human mobility, captured by mobile phone traces, to show that the predictions of the CTRW models are in systematic conflict with the empirical results. We introduce two principles that govern human trajectories, allowing us to build a statistically self-consistent microscopic model for individual human mobility. The model not only accounts for the empirically observed scaling laws but also allows us to analytically predict most of the pertinent scaling exponents

    Narrative Exposure Therapy as a treatment for child war survivors with posttraumatic stress disorder: Two case reports and a pilot study in an African refugee settlement

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    BACKGROUND: Little data exists on the effectiveness of psychological interventions for children with posttraumatic stress disorder (PTSD) that has resulted from exposure to war or conflict-related violence, especially in non-industrialized countries. We created and evaluated the efficacy of KIDNET, a child-friendly version of Narrative Exposure Therapy (NET), as a short-term treatment for children. METHODS: Six Somali children suffering from PTSD aged 12–17 years resident in a refugee settlement in Uganda were treated with four to six individual sessions of KIDNET by expert clinicians. Symptoms of PTSD and depression were assessed pre-treatment, post-treatment and at nine months follow-up using the CIDI Sections K and E. RESULTS: Important symptom reduction was evident immediately after treatment and treatment outcomes were sustained at the 9-month follow-up. All patients completed therapy, reported functioning gains and could be helped to reconstruct their traumatic experiences into a narrative with the use of illustrative material. CONCLUSIONS: NET may be safe and effective to treat children with war related PTSD in the setting of refugee settlements in developing countries

    Scaling properties of protein family phylogenies

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    One of the classical questions in evolutionary biology is how evolutionary processes are coupled at the gene and species level. With this motivation, we compare the topological properties (mainly the depth scaling, as a characterization of balance) of a large set of protein phylogenies with a set of species phylogenies. The comparative analysis shows that both sets of phylogenies share remarkably similar scaling behavior, suggesting the universality of branching rules and of the evolutionary processes that drive biological diversification from gene to species level. In order to explain such generality, we propose a simple model which allows us to estimate the proportion of evolvability/robustness needed to approximate the scaling behavior observed in the phylogenies, highlighting the relevance of the robustness of a biological system (species or protein) in the scaling properties of the phylogenetic trees. Thus, the rules that govern the incapability of a biological system to diversify are equally relevant both at the gene and at the species level.Comment: Replaced with final published versio
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