Search results for " CLUSTER"
showing 10 items of 2162 documents
Antiepileptic Drugs for the Treatment of Chronic and Episodic Cluster Headache: A Review.
2007
Cluster headache needs to be rapidly diagnosed and effectively managed, as the individual headache attacks that are characteristic of this disorder are excruciatingly painful and debilitating. Preventive therapies are necessary to reduce the frequency of attacks during the cluster period. However, preventive therapy for this disorder is limited by a lack of controlled evidence of efficacy and the potential for systemic toxicity. Recent progress has been made in understanding both the pathophysiological mechanisms underlying cluster headache and the mechanisms of action of the antiepileptic drug class for the treatment of primary headache syndromes. Newly available preliminary clinical trial…
Topographic maps for clustering and fast identification of bacteria using 16s housekeeping gene
2012
In microbial identification the standard method to attribute a specific name to a bacterial isolate relays on the comparison of morphologic and phenotypic characters to those described for type or typical strains. In the last years a new standard for identifying bacteria using genotypic information began to be developed. In this new approach phylogenetic relationships of bacteria could be determined by comparing a stable part of the bacteria genetic code, the so called "housekeeping genes". The most commonly used gene for taxonomic purposes for bacteria is the 16S rRNA. The goal of this chapter is to show that genotypic features can be used to build a topographic map for clustering of a lar…
Tourist destination network analysis: The ego network role
2017
This paper aims to analyse the different roles that enterprises have within a tourist destination by identifying the presence and possible role of leaders within the system. The Social Network Analysis (SNA) is a tool that offers a greater degree of understanding of the operation of the destination. The map of commercial relations between the leading players of tourist supply can provide greater insight into the main relations existing between enterprises and the principles that ensure and regulate operation. In keeping with this objective and building on the results of a previous paper (Iannolino and Ruggieri, 2012), the authors have focused their attention on the role of some enterprises …
CLUSTERING TOURIST LOCAL SYSTEMS BY VERTEX PARTITIONING AND LOCAL SEARCH
2014
Nonostante l’industria del turismo venga riconosciuta come un settore trainante per l’intera economia di un Paese, a tutt’oggi si registra una mancanza di criteri e metodologie ai fini della localizzazione, promozione e gestione di un Sistema Turistico Locale (STL). A tal fine, nel presente lavoro viene proposto un approccio di tipo quantitativo al problema sia della localizzazione che del dimensionamento ottimale di un STL tenendo conto di criteri e/o vincoli di natura geografica, economica e demografica. Il problema di ottimizzazione è rappresentato su grafo ed è risolto ricorrendo all’algoritmo di ricerca locale di Threshold Accepting (TA). Despite the importance of tourism as a leading …
Sustainability and Competitiveness in the Tourism Industry and Tourist Destinations: A Bibliometric Study
2019
This article presents an analysis of the state of the art on the relationship between tourism, sustainability and competitiveness (TSC)
Two master switch regulators trigger A40926 biosynthesis in Nonomuraea sp. strain ATCC 39727
2015
ABSTRACT The actinomycete Nonomuraea sp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of dalbavancin. Biosynthesis of A40926 is encoded by the dbv gene cluster, which contains 37 protein-coding sequences that participate in antibiotic biosynthesis, regulation, immunity, and export. In addition to the positive regulatory protein Dbv4, the A40926-biosynthetic gene cluster encodes two additional putative regulators, Dbv3 and Dbv6. Independent mutations in these genes, combined with bioassays and liquid chromatography-mass spectrometry (LC-MS) analyses, demonstrated that Dbv3 and Dbv4 are both required for antibiotic production, while inactivation of dbv6 had no effect. In …
Impact of DLK1-DIO3 imprinted cluster hypomethylation in smoker patients with lung cancer
2016
DNA methylation is important for gene expression and genome stability, and its disruption is thought to play a key role in the initiation and progression of cancer and other diseases. The DLK1-DIO3 cluster has been shown to be imprinted in humans, and some of its components are relevant to diverse pathological processes. The purpose of this study was to assess the methylation patterns of the DLK1-DIO3 cluster in patients with lung cancer to study its relevance in the pathogenesis of this disease. We found a characteristic methylation pattern of this cluster in smoking associated lung cancer, as compared to normal lung tissue. This methylation profile is not patent however in lung cancer of …
Relation entre transitivité et structure de communauté dans les réseaux complexes
2011
The relation between community structure and other topological properties in complex networks, has not been analyzed clearly. In this preliminary study, we explore experimentally the potential link between transitivity and community structure. We study the evolution of transitivity based on the quality of the community structure on artificially generated networks. Then we observe the evolution of community structure according to transitivity value. The results show a relationship between high transitivity and community structure. Additional analytical work is needed to identify the exact nature of this relationship.
Evolutionary transition to the ectomycorrhizal habit in the genomes of a hyperdiverse lineage of mushroom‐forming fungi
2022
International audience; Summary The ectomycorrhizal (ECM) symbiosis has independently evolved from diverse types of saprotrophic ancestors. In this study, we seek to identify genomic signatures of the transition to the ECM habit within the hyper-diverse Russulaceae. We present comparative analyses of the genomic architecture and the total and secreted gene repertoires of 18 species across the order Russulales of which 13 are newly sequenced, including a representative of a saprotrophic member of Russulaceae, Gloeopeniophorella convolvens. The genomes of ECM Russulaceae are characterized by a loss of genes for plant cell-wall degrading enzymes (PCWDEs), an expansion of genome size through in…
Rotational spectra of gauche perfluoro-n-butane, C4F10; perfluoro-iso-butane, (CF3)3CF; and tris(trifluoromethyl)methane, (CF3)3CH
2007
Abstract The microwave spectra of the gauche conformer of perfluoro- n -butane, n -C 4 F 10 , of perfluoro- iso -butane, (CF 3 ) 3 CF, and of tris(trifluoromethyl)methane, (CF 3 ) 3 CH, have been observed and assigned. The rotational and centrifugal distortion constants for gauche n -C 4 F 10 are: A = 1058.11750(7) MHz, B = 617.6832(1) MHz, C = 552.18794(1) MHz, Δ J = 0.0257(5) kHz, δ J = 0.0052(3) kHz. A C–C–C–C dihedral angle, ω , of ∼55° has been determined. These values agree well with those obtained from a coupled cluster (CCSD/cc-PVTZ) calculation. The rotational and centrifugal distortion constants for iso -C 4 F 10 and iso -C 4 HF 9 are: B o = 816.4519(4) MHz, D J = 0.023(2) …