Although all bilaterian animals have a related set of Hox genes, the genomic organization of this gene complement comes in different flavors. In some unrelated species, Hox genes are clustered; in others, they are not. This indicates that the bilaterian ancestor had a clustered Hox gene family and that, subsequently, this genomic organization was either maintained or lost. Remarkably, the tight...

Dnmt1 epigenetically propagates symmetrical CG methylation in many eukaryotes. Their genomes are typically depleted of CG dinucleotides because of imperfect repair of deaminated methylcytosines. Here, we extensively survey diverse species lacking Dnmt1 and show that, surprisingly, symmetrical CG methylation is nonetheless frequently present and catalyzed by a different DNA methyltransferase fam...

the purpose of this research was the the role of coping styles and social support in discriminating of students with high and low test anxiety. 387 of students in azad university of kermanshah selected by clustered sampling and filled the students coping scale and multidimensional scale of perceived social support and test anxiety questionnaire. results indicated that there is meaningful correl...

This paper considers networks where relationships between nodes are represented by directed dissimilarities. The goal is to study methods that, based on the dissimilarity structure, output hierarchical clusters, i.e., a family of nested partitions indexed by a connectivity parameter. Our construction of hierarchical clustering methods is built around the concept of admissible methods, which are...

Almost all kinds of social data have a hierarchical or clustered structure. For example, studies of inheritance deal with a natural hierarchy where offspring are grouped within families. Offspring from the same parents tend to be more alike in their physical and mental characteristics than individuals chosen at random from the population at large. For instance, children from the same family may...

Previous research presented in numbers of studies strongly suggests that locating a cluster generates valuable benefits to clustered firms. These include better access suppliers and other scarce inputs, superior knowledge innovation, position from which build social network as well proximate successful competitors. Yet when the positive impact agglomeration clustering has been questioned on str...

We will present theory that underpins the use of null-space preconditioners, giving eigenvalue bounds that show that the eigenvalues of the preconditioned system are clustered when a good approximation to the null-space matrix can be found. Additionally, we will describe how two of the family of preconditioners, although indefinite and non-symmetric, can be applied with a Krylov method with a s...