Intracellular signal transduction plays a critical role in a number of invertebrate patterning processes. In recent years it has been shown that many steps in these processes require homologues of proteins that transduce signals in cultured mammalian cells. Knowledge of the biochemical function of the vertebrate proteins has made it easier to define the invertebrate signaling pathways. In turn,...

Understanding how global patterns of tissue movement and deformation emerge from the combined activities of many individual cells remains a central unsolved problem in developmental biology. We consider this problem in the context of ascidian notochord formation, in which simultaneous invagination and convergent extension transforms a monolayer plate of 40 cells into a cylindrical rod (Munro an...

Introduction In 1963, Cairns invented DNA fiber autoradiography to spread and visualize [H]thymidine-labeled chromosomal DNA from Escherichia coli cells (Fig. 1 A). Using this technique, bidirectional replication was found to start at a single site (Cairns, 1963; Prescott and Kuempel, 1972), but its position could not be determined. Meanwhile, genetic studies suggested that in E. coli, each aut...

INTRODUCTION The euryhaline killifish Fundulus heteroclitus lives in estuaries and salt marshes on the eastern coast of North America. Killifish must dynamically regulate their ion balance because of routine fluctuations in salinity in their natural environment. This species can tolerate changes in salinity from freshwater to nearly four times seawater (Griffith, 1974), and have therefore been ...

in 2004, rodr'{i}guez-lallena and '{u}beda-flores have introduced a class of bivariate copulas which generalizes some known families such as the farlie-gumbel-morgenstern distributions. in 2006, dolati and '{u}beda-flores presented multivariate generalizations of this class. then in 2011, kim et al. generalized rodr'{i}guez-lallena and '{u}beda-flores' study to any...

Data envelopment analysis (DEA) is a nonstochastic and nonparametric linear programming technique where a set of units are evaluated according to their input consumption and output production (Charnes et al. (1978)). Given that DEA efficiency analysis can be influenced by the presence of outliers, Banker and Chang (2006) proposed a method to detect atypical units through the super-efficiency mo...

In recent years, it has become common knowledge that we, and the many organisms around us, are symbiotic creatures, harbouring large numbers of internal and external microbial residents. Research on symbiosis has progressed remarkably since the days of van Leeuwenhoek and de Bary, whose discoveries paved the way for over two centuries of fascinating work. Indeed, since their findings on bacteri...

The mitochondrial genome of 23 wild-type strains belonging to three different species of the filamentous fungus Podospora was examined. Among the 15 optional sequences identified are two intronic reading frames, nadl-i4-orfl and coxl-i7~$. We show that the presence of these sequences was strictly correlated with tightly clustered nucleotide substitutions in the adjacent exon. This correlation a...

introduction: zinc (zn) is cofactor of more than 300 enzymes and is needed for growth, dna synthesis, immunity and other important cellular processes (wood, 2000). cobalt (co) has been demonstrated to be an essential nutrient for ruminants and is required by ruminal microorganisms for the synthesis of vitamin b12 (mcdowell, 2000). selenium is an integral component of the enzyme glutathione pero...