Search results for "Cluster Analysis"
showing 10 items of 848 documents
Genetic divergence between morphological forms of brown troutSalmo truttaL. in the Balkan region of Macedonia
2010
The objective of this study was to characterize the genetic structure of two Balkan brown trout morphotypes, Salmo macedonicus and Salmo pelagonicus, and to test whether molecular traits support the species’ status proposed by traditional morphological identification. The mitochondrial DNA 12S-rDNA, cyt b and control region genes were sequenced in 15 specimens collected from three localities in the Former Yugoslav Republic of Macedonia. The results of these markers did not support the taxonomic category of species but confirmed the existence of two morphotypes, Salmo trutta macedonicus and Salmo trutta pelagonicus, in the Aegean–Adriatic lineages of the Salmo trutta species complex.
L'isola che se ne va
2020
Le università rivestono un ruolo fondamentale per un territorio, oltre ad essere un luogo di alta formazione e quindi di creazione di capitale umano, la letteratura ha evidenziato che tali istituzioni attraverso il knowledge spillover possono talvolta rappresentare il motore dell’innovazione e quindi dello sviluppo economico (Wolfe 2005). Nonostante queste importanti funzioni, per garantirsi le risorse necessarie a portare avanti la propria attività le università italiane hanno un crescente bisogno di sviluppare la propria capacità di allargare il bacino di attrazione degli studenti, in quanto: i) parte della quota base del Fondo di Funzionamento Ordinario (FFO) ricevuta dal Ministero dell’…
Telechelic Star Polymers as Self-Assembling Units from the Molecular to the Macroscopic Scale
2012
By means of multiscale molecular simulations, we show that telechelic-star polymers are a simple, robust, and tunable system, which hierarchically self-assembles into soft-patchy particles and mechanically stabilizes selected, open crystalline structures. The self-aggregating patchy behavior can be fully controlled by the number of arms per star and by the fraction of attractive monomeric units at the free ends of the arms. Such self-assembled soft-patchy particles while forming, upon augmenting density, gel-like percolating networks, preserve properties as particle size, number, and arrangement of patches per particle. In particular, we demonstrate that the flexibility inherent in the soft…
Solvates of Dasatinib: Diversity and Isostructurality
2015
A series of dasatinib crystalline forms were obtained, and a hierarchical cluster analysis of their powder X-ray diffraction patterns was performed. The resulting dendrogram implies 3 structural groups. The crystal structures of several solvates representing 2 of these groups were determined. The crystal structure analysis confirms the isostructurality of solvates within structural group I and suggests a correlation between solvent molecule size and trends in crystal structures within this group. In addition, the formation relationships in 2-solvent media between different dasatinib solvate groups were determined. The formation preference of solvates was found to follow the ranking group I …
Distributed evolutionary approach to data clustering and modeling
2014
In this article we describe a framework (DEGA-Gen) for the application of distributed genetic algorithms for detection of communities in networks. The framework proposes efficient ways of encoding the network in the chromosomes, greatly optimizing the memory use and computations, resulting in a scalable framework. Different objective functions may be used for producing division of network into communities. The framework is implemented using open source implementation of MapReduce paradigm, Hadoop. We validate the framework by developing community detection algorithm, which uses modularity as measure of the division. Result of the algorithm is the network, partitioned into non-overlapping co…
Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation
2003
SUMMARY Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell–cell and cell–matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph…
Study of polymorphisms in the promoter region of ovine β-lactoglobulin gene and phylogenetic analysis among the Valle del Belice breed and other shee…
2012
The aim of this work was to sequence the promoter region of b-lactoglobulin (BLG) gene in four sheep breeds, in order to identify polymorphisms, infer and analyze haplotypes, and phylogenetic relationship among the Valle del Belice breed and the other three breeds considered as ancestors. Sequencing analysis and alignment of the obtained sequences showed the presence of 36 single nucleotide polymorphisms (SNPs) and one deletion. A total of 22 haplotypes found in ‘‘best’’ reconstruction were inferred considering the 37 polymorphic sites identified. Haplotypes were used for the reconstruction of a phylogenetic tree using the Neighbor-Joining algorithm. The number of polymorphisms identified s…
Phylogenetic relationships of the family Campulidae (Trematoda) based on 18S rRNA sequences
1998
Traditionally, the family Campulidae has been associated either with the family Fasciolidae, parasites of ruminants, or the Acanthocolpidae, parasites of fishes, based on morphological similarities. Since morphology does not seem to resolve clearly the problem of the relationships of campulids, we have used the sequences of the 18S rRNA gene of the campulids Zalophotrema hepaticum, Campula oblonga and Nasitrema globicephalae, the fasciolid Fasciola hepatica, the acanthocolpid Stephanostomum baccatum and the outgroup Schistosoma mansoni to infer a phylogeny. Maximum parsimony and neighbour-joining methods were applied. Both methods indicated that campulids are closer to acanthocolpids than f…
Wild Sicilian Rosemary: Phytochemical and Morphological Screening and Antioxidant Activity Evaluation of Extracts and Essential Oils
2015
To identify the best biotypes, an extensive survey of Sicilian wild rosemary was carried out by collecting 57 samples from various sites, followed by taxonomic characterization from an agronomic perspective. All the biotypes collected were classified as Rosmarinus officinalis L. A cluster analysis based on the morphological characteristics of the plants allowed the division of the biotypes into seven main groups, although the characteristics examined were found to be highly similar and not area-dependent. Moreover, all samples were analyzed for their phytochemical content, applying an extraction protocol to obtain the nonvolatile components and hydrodistillation to collect the essential oil…
The Essential Oil Compositions of Three Teucrium Taxa Growing Wild in Sicily: HCA and PCA Analyses
2021
The chemical composition and the qualitative and quantitative variability of the essential oils of three taxa belonging to the Teucrium genus were studied. The investigated taxa, that grow wild in Sicily, were Teucrium flavum L. (section Chamaedrys (Mill.) Scheb.), Teucrium montanum and Teucrium capitatum L. of section Polium (Mill.) Scheb. Essential oils were extracted by hydrodistillation and analyzed by GC-MS. In total, 74 compounds were identified. Sesquiterpene hydrocarbons were found to be the main group for T. flavum (48.3%). T. capitatum consisted essentially of monoterpene hydrocarbons (72.7%), with &alpha