506 research outputs found

    Coalescent histories for lodgepole species trees

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    Coalescent histories are combinatorial structures that describe for a given gene tree and species tree the possible lists of branches of the species tree on which the gene tree coalescences take place. Properties of the number of coalescent histories for gene trees and species trees affect a variety of probabilistic calculations in mathematical phylogenetics. Exact and asymptotic evaluations of the number of coalescent histories, however, are known only in a limited number of cases. Here we introduce a particular family of species trees, the \emph{lodgepole} species trees (λn)n0(\lambda_n)_{n\geq 0}, in which tree λn\lambda_n has m=2n+1m=2n+1 taxa. We determine the number of coalescent histories for the lodgepole species trees, in the case that the gene tree matches the species tree, showing that this number grows with m!!m!! in the number of taxa mm. This computation demonstrates the existence of tree families in which the growth in the number of coalescent histories is faster than exponential. Further, it provides a substantial improvement on the lower bound for the ratio of the largest number of matching coalescent histories to the smallest number of matching coalescent histories for trees with mm taxa, increasing a previous bound of (π/32)[(5m12)/(4m6)]mm(\sqrt{\pi} / 32)[(5m-12)/(4m-6)] m \sqrt{m} to [m1/(4e)]m[ \sqrt{m-1}/(4 \sqrt{e}) ]^{m}. We discuss the implications of our enumerative results for phylogenetic computations

    On the number of ranked species trees producing anomalous ranked gene trees

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    Analysis of probability distributions conditional on species trees has demonstrated the existence of anomalous ranked gene trees (ARGTs), ranked gene trees that are more probable than the ranked gene tree that accords with the ranked species tree. Here, to improve the characterization of ARGTs, we study enumerative and probabilistic properties of two classes of ranked labeled species trees, focusing on the presence or avoidance of certain subtree patterns associated with the production of ARGTs. We provide exact enumerations and asymptotic estimates for cardinalities of these sets of trees, showing that as the number of species increases without bound, the fraction of all ranked labeled species trees that are ARGT-producing approaches 1. This result extends beyond earlier existence results to provide a probabilistic claim about the frequency of ARGTs

    Sulle rive di Babele : gli esercizi di traduzione di Paul Celan per Gisèle Celan-Lestrange

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    Der Dichter Paul Celan übersetzte aus sieben Sprachen ins Deutsche, weigerte sich aber zeit seines Lebens seine eigenen Gedichte zu übertragen. Zu der Frage, ob seine Lyrik überhaupt übersetzbar sei, hat er sich zudem meistens sehr skeptisch geäußert. Doch für seine Frau, die französische Künstlerin Gisèle Celan-Lestrange, verfasste er Vokabellisten und Interlinearübersetzungen zu einigen seiner Gedichte. Anhand des Briefwechsels, den die Partner fast 20 Jahre lang führten, soll die Bedeutung des Sprachwechsels im Leben und Werk Celans thematisiert werden. Denn der Wechsel zwischen dem Französischen der Briefe und dem Deutschen der Gedichte, zwischen der Sprache des Exils und der Muttersprache spiegelt zweifellos die Frage nach der individuellen und künstlerischen Identität wider. Die im Briefwechsel enthaltenen französischen Fassungen der Gedichte stellen daher einen absoluten Einzelfall dar. Der Dichter verstand diese Texte nicht als Übertragungen im vollen Sinn des Wortes, trotzdem gewähren sie dem Interpreten einen einzigartigen Einblick in die Werkstatt des Dichters. Die vergleichende Analyse der deutschen und französischen Fassung der Einzeltexte zeigt, wie die Tätigkeit des Dichters und die des Übersetzers Paul Celans zueinander beisteuerten

    Anna Blume "attraverso lo specchio". Traduzione poetica e ricezione testuale in Kurt Schwitters (attraverso Lewis Carroll)

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    This essay takes Carroll's novel "Through the Looking-Glass" as a starting point to discuss the experimentation with linguistic material by “Merz” poet and artist Kurt Schwitters. Dwelling on the lyric "AN ANNA BLUME!" and the reception of the text in Europe after its first publication, the essay will focus on some translation issues starting, in the first place, with the Italian translations. Far from being 'nonsensical', the literature of nonsense, of which both Carroll and Schwitters are major exponents, highlights the rich semantic, sonorous, graphic and typographic multidimensionality of language and emphasises once again how translation, especially the translation of poetry, or more generally the translation of rhymes, word plays and idioms, is comparable to a challenge, to the resolution of a riddle to which the various possible solutions have first been pondered for a long time. However, this is not an impossible challenge as the postulate of poetry's untranslatability states

    Food safety in collective catering: Knowledge, attitudes and correct application of GHP/GMP knowledge among foodservice workers

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    Food safety critically reliant on the behaviors adopted by foodservice personnel, involved in various stages of meal preparation, from the supply of raw food materials until its distribution to the consumer. The purpose of this work was to collect information on the level of knowledge on food safety, the correct application of the Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP) and the attitudes of the operators involved in collective catering. The survey was conducted among 15 social catering companies in Apulia (Italy) using a modified Sharif and Al-Malki (2010) anonymous questionnaire intended to assess the knowledge, attitudes and practices of the food handlers. The results highlight the need to improve both knowledge and practices regarding food hygiene and safety in order to minimize the risk of transmitting foodborne diseases. More careful planning, implementation, monitoring and evaluation of training programs for foodservice workers is required, taking into consideration the provisions of European food laws

    Hospital admissions for vitamin D related conditions and subsequent immune-mediated disease: record-linkage studies

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    PMCID: PMC3729414The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/11/171. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Recurrent Ascending Colon Cancer Manifesting as Inferior Vena cava Thrombus

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    We report an extremely rare case of recurrent ascending colon cancer manifesting as inferior vena cava (IVC) thrombus. A 77-year-old woman previously diagnosed with ascending colon cancer underwent right hemicolectomy with lymph node dissection. Though the tumor invaded the retroperitoneum and involved the right ovarian artery and vein, curative operation was performed. The patient took 5-FU p.o. Two and a half years later, tumor thrombus in the IVC extending into the right atrium was incidentally found and diagnosed as recurrence of colon cancer by biopsy. RF-induced hyperthermia using 5-FU and CDDP i.v. was immediately performed, but she died after 6 months because of multiple liver and pulmonary metastases. In treating colon cancers invading the retroperitoneum, it should be recalled that some cases recur as tumor thrombus in the IVC and that close follow-up is therefore necessary

    Neurologic complications of acute hepatitis E virus infection.

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    To assess the prevalence and clinical features of neurologic involvement in patients with acute hepatitis E virus (HEV) infection in Southern Switzerland. Among 1,940 consecutive patients investigated for acute hepatitis E, we identified 141 cases of acute of HEV infection (anti-HEV immunoglobulin M and immunoglobulin G both reactive and/or HEV RNA positive) between June 2014 and September 2017. Neurologic cases were followed up for 6 months. We compared patients with and without neurologic symptoms. Neurologic symptoms occurred in 43 acute HEV cases (30.4%) and consisted of neuralgic amyotrophy (NA, n = 15, 10.6%) and myalgia (n = 28, 19.8%). All NA cases were immunocompetent. Men had higher odds (OR = 5.2, CI 1.12-24.0, p = 0.03) of developing NA after infection with HEV, and in 3 couples simultaneously infected with HEV, only men developed NA. Bilateral involvement of NA was predominant (2:1) and occurred only in men. Seven NA cases were viremic (all genotype 3), but HEV was undetectable in their CSF. In the acute phase of NA, 9 patients were treated with intravenous immunoglobulin and 4 with prednisone, reporting no side effects and improvement in pain and strength. Myalgia occurred both without (n = 16) or with (n = 12) concomitant elevated serum creatinine kinase. Seven cases with myalgia in the shoulder girdle did not have muscle weakness ("forme fruste" of NA). Neurologic symptoms occurred in one-third of acute HEV infections and consisted of NA and myalgia. NA seems to occur more frequently in men infected by HEV and has a predominant (but not exclusive) bilateral involvement

    Impact of month of birth on the development of autoimmune thyroid disease in the United Kingdom and Europe

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    CONTEXT: Viral/bacterial infection is proposed as a trigger for the autoimmune thyroid diseases (AITD): Graves' disease (GD) and Hashimoto's thyroiditis (HT). Previous studies in European Caucasian AITD subjects found higher birth rates in the autumn/winter, suggesting those born in the autumn/winter experience increased viral/bacterial exposure after birth, impacting upon immune system development and predisposing to AITD later in life. OBJECTIVE: Month of birth effects were investigated in three independent European Caucasian AITD datasets. DESIGN: Variation in GD and HT onset was compared across months and seasons, with fluctuations across all 12 months analyzed using a Walter-Elwood test. SETTING: The study was conducted at a research laboratory. PATIENTS: National UK Caucasian AITD Case Control Collection (2746 GD and 502 HT compared with 1 423 716 UK births), National UK Caucasian GD Family Collection (239 GD and 227 unaffected siblings), and OXAGEN AITD Caucasian Family Collection (885 GD, 717 HT, and 794 unaffected siblings of European Caucasian decent). MAIN OUTCOME MEASURES: Case-control and family-based association studies were measured. RESULTS: No consistent month of birth effects were detected in GD females or males across all three collections. In HT females from the OXAGEN AITD Caucasian Family Collection, slightly higher birth rates were detected in autumn (Walter's test statistic = 7.47, P = .024) however, this was not seen in the HT females from the case-control cohort. CONCLUSION: Our results suggest in UK/Northern European Caucasian GD subjects, month of birth does not impact on AITD development. Although some month of birth effects for HT females in one collection cannot be excluded, only further work in larger European Caucasian AITD collections can confirm these effects
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