The four-in-a-tree problem in triangle-free graphs

The three-in-a-tree algorithm of Chudnovsky and Seymour decides in time O(n4) whether three given vertices of a graph belong to an induced tree. Here, we study four-in-a-tree for triangle-free graphs. We give a structural answer to the following question : how does look like a triangle-free graph such that no induced tree covers four given vertices ? Our main result says that any such graph must have the "same structure", in a sense to be defined precisely, as a square or a cube. We provide an O(nm)-time algorithm that given a triangle-free graph G together with four vertices outputs either an induced tree that contains them or a partition of V(G) certifying that no such tree exists. We prove that the problem of deciding whether there exists a tree T covering the four vertices such that at most one vertex of T has degree at least 3 is NP-complete.Three, four, tree, algorithm, 3-in-a-tree, 4-in-a-tree, triangle-free graphs.

Texture, realism, performance: exploring the intersection of transtexts and the contemporary sitcom

Contemporary US sitcom is at an interesting crossroads: it has received an increasing amount of scholarly attention (e.g. Mills 2009; Butler 2010; Newman and Levine 2012; Vermeulen and Whitfield 2013), which largely understands it as shifting towards the aesthetically and narratively complex. At the same time, in the post-broadcasting era, US networks are particularly struggling for their audience share. With the days of blockbuster successes like Must See TV’s Friends (NBC 1994-2004) a distant dream, recent US sitcoms are instead turning towards smaller, engaged audiences. Here, a cult sensibility of intertextual in-jokes, temporal and narrational experimentation (e.g. flashbacks and alternate realities) and self-reflexive performance styles have marked shows including Community (NBC 2009-2015), How I Met Your Mother (CBS 2005-2014), New Girl (Fox 2011-present) and 30 Rock (NBC 2006-2013). However, not much critical attention has so far been paid to how these developments in textual sensibility in contemporary US sitcom may be influenced by, and influencing, the use of transmedia storytelling practices, an increasingly significant industrial concern and rising scholarly field of enquiry (e.g. Jenkins 2006; Mittell 2015; Richards 2010; Scott 2010; Jenkins, Ford and Green 2013). This chapter investigates this mutual influence between sitcom and transmedia by taking as its case studies two network shows that encourage invested viewership through their use of transtexts, namely How I Met Your Mother (hereafter HIMHM) and New Girl (hereafter NG). As such, it will pay particular attention to the most transtextually visible character/actor from each show: HIMYM’s Barney Stinson, played by Neil Patrick Harris, and NG’s Schmidt, played by Max Greenfield. This chapter argues that these sitcoms do not simply have their particular textual sensibility and also (happen to) engage with transmedia practices, but that the two are mutually informing and defining. This chapter explores the relationships and interplay between sitcom aesthetics, narratives and transmedia storytelling (or industrial transtexts), focusing on the use of multiple delivery channels in order to disperse “integral elements of a fiction” (Jenkins, 2006 95-6), by official entities such as the broadcasting channels. The chapter pays due attention to the specific production contexts of both shows and how these inform their approaches to transtexts. This chapter’s conceptual framework will be particularly concerned with how issues of texture, the reality envelope and accepted imaginative realism, as well as performance and the actor’s input inform and illuminate contemporary sitcoms and transtexts, and will be the first scholarly research to do so. It will seek out points of connections between two (thus far) separate strands of scholarship and will move discussions on transtexts beyond the usual genre studied (i.e. science-fiction and fantasy), as well as make a contribution to the growing scholarship on contemporary sitcom by approaching it from a new critical angle. On the basis that transmedia scholarship stands to benefit from widening its customary genre choice (i.e. telefantasy) for its case studies and from making more use of in-depth close analysis in its engagement with transtexts, the chapter argues that notions of texture, accepted imaginative realism and the reality envelope, as well as performance and the actor’s input deserve to be paid more attention to within transtext-related scholarship

The four-in-a-tree problem in triangle-free graphs

URL des Documents de travail : http://ces.univ-paris1.fr/cesdp/cesdp2008.htmlDocuments de travail du Centre d'Economie de la Sorbonne 2008.23 - ISSN : 1955-611XThe three-in-a-tree algorithm of Chudnovsky and Seymour decides in time O(n4) whether three given vertices of a graph belong to an induced tree. Here, we study four-in-a-tree for triangle-free graphs. We give a structural answer to the following question : how does look like a triangle-free graph such that no induced tree covers four given vertices ? Our main result says that any such graph must have the "same structure", in a sense to be defined precisely, as a square or a cube. We provide an O(nm)-time algorithm that given a triangle-free graph G together with four vertices outputs either an induced tree that contains them or a partition of V(G) certifying that no such tree exists. We prove that the problem of deciding whether there exists a tree T covering the four vertices such that at most one vertex of T has degree at least 3 is NP-complete.L'algorithme "three-in-a-tree" de Chudnovsky et Seymour décide en temps O(n4) si trois sommets donnés d'un graphe appartiennent à un arbre induit. Ici, nous étudions four-in-a-tree pour les graphes sans triangles. Nous donnons une réponse structurelle à la question suivante : à quoi ressemble un graphe sans triangles dont aucun arbre induit ne couvre quatre sommets donnés ? Notre résultat principal affirme qu'un tel graphe doit avoir la "même structure", dans un sens précisemment défini, qu'un carré ou un cube. Nous donnons un algorithme en temps O(nm) qui étant donné un graphe sans triangles G et quatre de ses sommets, retourne ou bien un arbre induit qui contient les sommets, ou bien une partition de V(G) certifiant qu'un tel arbre n'existe pas. Nous prouvons que le problème consistant à décider s'il existe un arbre T couvrant les quatre sommets et tel qu'au plus un sommet de T est de degré au moins 3 est NP-complet

Queensland's high risk foot database: tracking the length and width of Queensland's foot ulcers [Conference Abstract]

Background Foot ulcers are a leading cause of avoidable hospital admissions and lower extremity amputations. However, large clinical studies describing foot ulcer presentations in the ambulatory setting are limited. The aim of this descriptive observational paper is to report the characteristics of ambulatory foot ulcer patients managed across 13 of 17 Queensland Health & Hospital Services. Methods Data on all foot ulcer patients registered with a Queensland High Risk Foot Form (QHRFF) was collected at their first consult in 2012. Data is automatically extracted from each QHRFF into a Queensland high risk foot database. Descriptive statistics display age, sex, ulcer types and co-morbidities. Statewide clinical indicators of foot ulcer management are also reported. Results Overall, 2,034 people presented with a foot ulcer in 2012. Mean age was 63(±14) years and 67.8% were male. Co-morbidities included 85% had diabetes, 49.7% hypertension, 39.2% dyslipidaemia, 25.6% cardiovascular disease, 13.7% kidney disease and 12.2% smoking. Foot ulcer types included 51.6% neuropathic, 17.8% neuro-ischaemic, 7.2% ischaemic, 6.6% post-surgical and 16.8% other; whilst 31% were infected. Clinical indicator results revealed 98% had their wound categorised, 51% received non-removable offloading, median ulcer healing time was 6-weeks and 37% had ulcer recurrence. Conclusion This paper details the largest foot ulcer database reported in Australia. People presenting with foot ulcers appear predominantly older, male with several co-morbidities. Encouragingly it appears most patients are receiving best practice care. These results may be a factor in the significant reduction of Queensland diabetes foot-related hospitalisations and amputations recently reported

Lumen-apposing metal stent placement after endoscopic ultrasound-guided duodenojejunal anastomosis for direct access to excluded jejunal limb: findings after 5 years

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Success and the TV industry: how practitioners apprehend the notion(s) of success in their discourses within the Anglophone Transatlantic Television Industry

This thesis explores the discourses of success within the Anglophone transatlantic television industry through the semi-structured interviews of sixteen industry practitioners. The TV industry has long been studied in media studies, its working conditions discussed in production studies, its texts scrutinised in TV studies; but what drives the TV industry? What is ‘success’ to television industry practitioners? How do they apprehend it and discuss it? Looking at this key element through those at the heart of it is this research’s purpose, and a necessary step for cultural, production and television studies to better comprehend the industry and what drives it and its members. After discussing the methods selected for this research and bringing forth a new, sevenfold taskbased industry categorisation, my research will tackle its subject of enquiry through three main topics: •the perception of decision-makers by industry practitioners •the industrial executive discourses of success among the different industry constituents (networks/cable/premium/public channels/studios); •the personal definitions of success of all practitioners (and their link to industrial/professional success). This research will engage with many academic fields: from discourse analysis and industrial sociology to organisational research and management psychology, through production studies, cultural studies and film/television/media studies, giving it a clearly multidisciplinary scope. With this thesis, I also wish to further help bridge the gap between academic and industrial expertise. By doing so, and making sense of industrial and personal ideas of success, my research aims at developing a new framework for it, thereby proposing to academics a first approach to the notion of success in this industry

Le fardeau de la varicelle et du zona à la suite de l'introduction du programme de vaccination à une puis à deux doses

Le but de l'étude a été d'évaluer le fardeau associé à la varicelle et au zona au Québec à la suite de l'introduction du programme public de vaccination contre la varicelle à une puis à deux doses. La première dose contre la varicelle a été introduite dans le programme régulier d'immunisation québécois en 2006 et la deuxième dose a été mise en place en 2016. La revue de littérature a démontré que l'ajout d'une deuxième dose de vaccin pouvait permettre de réduire davantage les consultations, les hospitalisations et les décès liés à la varicelle et au zona (chez les 0-9 ans). Cette étude a utilisé un devis de recherche quantitatif à visée descriptive afin de dresser le portrait de la varicelle et du zona au Québec de 1996 à 2018. Elle a utilisé des données clinico-administratives de la Régie de l'assurance maladie du Québec (RAMQ), les données Maintenance et exploitation des données pour l'étude de la clientèle hospitalière (MED-ECHO), la Banque de données communes des urgences (BDCU) ainsi que le registre de décès de l'Institut de la statistique du Québec (ISQ) pour mesurer le fardeau de la varicelle et du zona au Québec. Entre la période pré-vaccinale (1996-2000) et la période de vaccination à une dose contre la varicelle (2006-2015), une baisse du taux de consultation pour varicelle de 93 % a été enregistrée. Il y a eu une réduction de 83 % du taux d'hospitalisation pour la varicelle entre la période vaccinale à deux doses (2017-2018) et la période vaccinale dans le secteur privé (2001-2005). Il y a eu une diminution de 76 % du taux d'hospitalisation pour le zona chez les 0-9 ans entre la période 2017-2018 et la période 2001-2005. Une poursuite de la surveillance est nécessaire pour mieux cerner l'impact de la deuxième dose.The purpose of this study was to assess the burden associated with varicella and herpes zoster in Quebec following the introduction of the one and two-dose public varicella vaccination programs. The first dose of the varicella vaccine was introduced as part of the regular immunization program in 2006, and the second dose was introduced in 2016. A review of the literature conducted outside Quebec demonstrated that the addition of a second dose of vaccine could further reduce consultations, hospitalizations and deaths related to varicella and shingles (0-9 years old). This study used a quantitative, descriptive research design in order to evaluate the burden of varicella and shingles in Quebec from 1996 to 2018. It used clinico-administrative data from the Régie de l'assurance maladie du Québec (RAMQ), the Maintenance et exploitation des données pour l'étude de la clientèle hospitalière (MED-ECHO), the Banque de données communes des urgences (BDCU), and the Institut de la statistique du Québec (ISQ) death registry to measure the burden of varicella and herpes zoster in Quebec. Between the pre-vaccination era (1996-2000) and the one-dose varicella vaccination era (2006-2015), a 93 % decrease in the rate of varicella consultations was recorded. There was an 83% reduction in the hospitalization rate for varicella between the two-dose vaccine period (2017-2018) and the pre-vaccine period (1996-2000). There was a 76 % decrease in the hospitalization rate for shingles in 0-9 years olds between 2017-2018 and the private sector vaccine period (2001-2005). Continued surveillance is necessary in order to measure the impact of the second dose

Trophic interactions in the coastal ecosystem of Morocco: An Ecopath approach

Abstract The Moroccan Atlantic coast is considered as one of the richest fishing areas in the world, having rich biodiversity, and supporting the fisheries sector. However, studies have shown that the ecosystem presently suffers from overexploitation of fishery resources and environmental degradation. To quantify these impacts, the characterization of the ecosystem is essential. In this work, an Ecopath model (EwE), which assumes steady-state and mass-balanced conditions for the Moroccan Atlantic coast ecosystem, was developed and balanced. Network analysis included in the Ecopath software package was used to estimate trophic interactions and the maturity of the ecosystem. The model consisted of 29 functional groups. The results showed a Total System Throughput (TST) which is comprised mainly of flows into detritus, followed by export, consumption, and respiration. Systemic indicators, suggest that the Moroccan Atlantic coast is an immature and developing ecosystem. Further observations on the functioning and dynamics of the ecosystem are discussed