23 resultados para Star-clusters


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Defining the limits of an urban agglomeration is essential both for fundamental and applied studies in quantitative and theoretical geography. A simple and consistent way for defining such urban clusters is important for performing different statistical analysis and comparisons. Traditionally, agglomerations are defined using a rather qualitative approach based on various statistical measures. This definition varies generally from one country to another, and the data taken into account are different. In this paper, we explore the use of the City Clustering Algorithm (CCA) for the agglomeration definition in Switzerland. This algorithm provides a systemic and easy way to define an urban area based only on population data. The CCA allows the specification of the spatial resolution for defining the urban clusters. The results from different resolutions are compared and analysed, and the effect of filtering the data investigated. Different scales and parameters allow highlighting different phenomena. The study of Zipf's law using the visual rank-size rule shows that it is valid only for some specific urban clusters, inside a narrow range of the spatial resolution of the CCA. The scale where emergence of one main cluster occurs can also be found in the analysis using Zipf's law. The study of the urban clusters at different scales using the lacunarity measure - a complementary measure to the fractal dimension - allows to highlight the change of scale at a given range.

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Originally, the Chlamydiales order was represented by a single family, the Chlamydiaceae, composed of several pathogens, such as Chlamydia trachomatis, Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia abortus. Recently, 6 new families of Chlamydia-related bacteria have been added to the Chlamydiales order. Most of these obligate intracellular bacteria are able to replicate in free-living amoebae. Amoebal co-culture may be used to selectively isolate amoeba-resisting bacteria. This method allowed in a previous work to discover strain CRIB 30, from an environmental water sample. Based on its 16S rRNA gene sequence similarity with Criblamydia sequanensis, strain CRIB 30 was considered as a new member of the Criblamydiaceae family. In the present work, phylogenetic analyses of the genes gyrA, gyrB, rpoA, rpoB, secY, topA and 23S rRNA as well as MALDI-TOF MS confirmed the taxonomic classification of strain CRIB 30. Morphological examination revealed peculiar star-shaped elementary bodies (EBs) similar to those of C. sequanensis. Therefore, this new strain was called "Estrella lausannensis". Finally, E. lausannensis showed a large amoebal host range and a very efficient replication rate in Acanthamoeba species. Furthermore, E. lausannensis is the first member of the Chlamydiales order to grow successfully in the genetically tractable Dictyostelium discoideum, which opens new perspectives in the study of chlamydial biology.

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This paper aims at detecting spatio-temporal clustering in fire sequences using space?time scan statistics, a powerful statistical framework for the analysis of point processes. The methodology is applied to active fire detection in the state of Florida (US) identified by MODIS (Moderate Resolution Imaging Spectroradiometer) during the period 2003?06. Results of the present study show that statistically significant clusters can be detected and localized in specific areas and periods of the year. Three out of the five most likely clusters detected for the entire frame period are localized in the north of the state, and they cover forest areas; the other two clusters cover a large zone in the south, corresponding to agricultural land and the prairies in the Everglades. In order to analyze if the wildfires recur each year during the same period, the analyses have been performed separately for the 4 years: it emerges that clusters of forest fires are more frequent in hot seasons (spring and summer), while in the southern areas, they are widely present during the whole year. The recognition of overdensities of events and the ability to locate them in space and in time can help in supporting fire management and focussing on prevention measures.

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A 47 ans, Edwige Feuillère est la vedette principale du Blé en herbe (1954), où elle incarne une femme d'âge mûr qui entreprend l'initiation amoureuse d'un jeune homme ; quatre ans plus tard, elle joue dans En cas de malheur le rôle d'une épouse qui, dans l'abnégation la plus complète, accepte les infidélités de son mari et s'efface devant le couple formé par Jean Gabin (54 ans) et Brigitte Bardot (24 ans). La place accordée aux deux personnages interprétés par Feuillère sera examinée en termes de construction de l'image d'une star vieillissante à travers l'étude du triangle amoureux qui structure le récit de ces deux adaptations (qu'il s'agira de comparer aux romans de Colette et de Simenon dont elles sont issues), de la stratégie promotionnelle pratiquée et des discours émis à propos de Feuillère au sein de la réception critique. Le contexte de production des films ainsi que certaines versions non retenues du scénario seront discutées à partir des archives du fonds Claude Autant-Lara de la Cinémathèque suisse.

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OBJECTIVE: Body mass index (BMI) may cluster in space among adults and be spatially dependent. Whether and how BMI clusters evolve over time in a population is currently unknown. We aimed to determine the spatial dependence of BMI and its 5-year evolution in a Swiss general adult urban population, taking into account the neighbourhood-level and individual-level characteristics. DESIGN: Cohort study. SETTING: Swiss general urban population. PARTICIPANTS: 6481 georeferenced individuals from the CoLaus cohort at baseline (age range 35-74 years, period=2003-2006) and 4460 at follow-up (period=2009-2012). OUTCOME MEASURES: Body weight and height were measured by trained healthcare professionals with participants standing without shoes in light indoor clothing. BMI was calculated as weight (kg) divided by height squared (m(2)). Participants were geocoded using their postal address (geographic coordinates of the place of residence). Getis-Ord Gi statistic was used to measure the spatial dependence of BMI values at baseline and its evolution at follow-up. RESULTS: BMI was not randomly distributed across the city. At baseline and at follow-up, significant clusters of high versus low BMIs were identified and remained stable during the two periods. These clusters were meaningfully attenuated after adjustment for neighbourhood-level income but not individual-level characteristics. Similar results were observed among participants who showed a significant weight gain. CONCLUSIONS: To the best of our knowledge, this is the first study to report longitudinal changes in BMI clusters in adults from a general population. Spatial clusters of high BMI persisted over a 5-year period and were mainly influenced by neighbourhood-level income.

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BACKGROUND: Rivaroxaban has become an alternative to vitamin-K antagonists (VKA) for stroke prevention in non-valvular atrial fibrillation (AF) patients due to its favourable risk-benefit profile in the restrictive setting of a large randomized trial. However in the primary care setting, physician's motivation to begin with rivaroxaban, treatment satisfaction and the clinical event rate after the initiation of rivaroxaban are not known. METHODS: Prospective data collection by 115 primary care physicians in Switzerland on consecutive nonvalvular AF patients with newly established rivaroxaban anticoagulation with 3-month follow-up. RESULTS: We enrolled 537 patients (73±11years, 57% men) with mean CHADS2 and HAS-BLED-scores of 2.2±1.3 and 2.4±1.1, respectively: 301(56%) were switched from VKA to rivaroxaban (STR-group) and 236(44%) were VKA-naïve (VN-group). Absence of routine coagulation monitoring (68%) and fixed-dose once-daily treatment (58%) were the most frequent criteria for physicians to initiate rivaroxaban. In the STR-group, patient's satisfaction increased from 3.6±1.4 under VKA to 5.5±0.8 points (P<0.001), and overall physician satisfaction from 3.9±1.3 to 5.4±0.9 points (P<0.001) at 3months of rivaroxaban therapy (score from 1 to 6 with higher scores indicating greater satisfaction). In the VN-group, both patient's (5.4±0.9) and physician's satisfaction (5.5±0.7) at follow-up were comparable to the STR-group. During follow-up, 1(0.19%; 95%CI, 0.01-1.03%) ischemic stroke, 2(0.37%; 95%CI, 0.05-1.34%) major non-fatal bleeding and 11(2.05%; 95%CI, 1.03-3.64%) minor bleeding complications occurred. Rivaroxaban was stopped in 30(5.6%) patients, with side effects being the most frequent reason. CONCLUSION: Initiation of rivaroxaban for patients with nonvalvular AF by primary care physicians was associated with a low clinical event rate and with high overall patient's and physician's satisfaction.

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BACKGROUND: The counting of poorly differentiated clusters of 5 or more cancer cells lacking a gland-like structure in a tumor mass has recently been identified among the histological features predictive of poor prognosis in colorectal cancer. MAIN BODY: Poorly differentiated clusters can easily be recognized in the histological sections of colorectal cancer routinely stained with haematoxylin and eosin. Despite some limitations related to specimen fragmentation, counting can also be assessed in endoscopic biopsies. Based on the number of poorly differentiated clusters that appear under a microscopic field of a ×20 objective lens (i.e., a microscopic field with a major axis of 1 mm), colorectal cancer can be graded into malignancies as follows: tumors with <5 clusters as grade 1, tumors with 5 to 9 clusters as grade 2, and tumors with ≥10 clusters as grade 3. High poorly differentiated cluster counts are significantly associated with peri-neural and lympho-vascular invasion, the presence of nodal metastases or micrometastases, as well as shorter overall and progression free survival to colorectal cancer. CONCLUSION: The morphological aspects and clinical relevance of poorly differentiated clusters counting in colorectal cancer are discussed in this review.