We have isolated cDNA clones derived from three mRNA sequences which are inducible by DIF, the putative stalk-specific morphogen of Dictyostelium. The three mRNA sequences are selectively expressed in cells on the stalk cell pathway of differentiation and we have compared them with previously characterized prestalk-enriched mRNA sequences. We find these latter sequences are expressed without a ...

The E. coli chromosome replication arms are polarized by motifs such as RRNAGGGS oligomers, found preferentially on leading strands. Their skew increases regularly from the origin to dif (the site in the center of the terminus where chromosome dimer resolution occurs), to reach a value of 90% near dif. Convergent information indicates that polarization in opposite directions from the dif region...

BACKGROUND Fairness is a critical component of defensible assessment. Candidates should perform according to ability without influence from background characteristics such as ethnicity or sex. However, performance differs by candidate background in many assessment environments. Many potential causes of such differences exist, and examinations must be routinely analysed to ensure they do not pre...

The dynamic increase factor (DIF) in the strength of concrete-like materials has been a subject extensive investigation and debate for many years. It now tends to be generally accepted that compression DIF as observed from standard sample tests is mainly attributable structural effect, whereas concrete under tension deemed governed by different mechanisms, probably more material micro-fracture ...

The study evaluated the comparability of two versions of a certification test: a paperand-pencil test (PPT) and computer-based test (CBT). An effect size measure known as Cohen’s d and differential item functioning (DIF) analyses were used as measures of comparability at the test and item levels, respectively. Results indicated that the effect sizes were small (d < 0.20) and not statistically s...

Homologous recombination between circular chromosomes generates dimers that cannot be segregated at cell division. Escherichia coli Xer site-specific recombination converts chromosomal and plasmid dimers to monomers. Two recombinases, XerC and XerD, act at the E. coli chromosomal recombination site, dif, and at related sites in plasmids. We demonstrate that Xer recombination at plasmid dif site...

The Xer site-specific recombination system of Escherichia coli is involved in the stable inheritance of circular replicons. Multimeric replicons, produced by homologous recombination, are converted to monomers by the action of two related recombinases XerC and XerD. Site-specific recombination at a locus, dif, within the chromosomal replication terminus region is thought to convert dimeric chro...

150 specimens from suspected herpes simplex genital and skin lesions were received in virus transport medium. They were inoculated into Hep-2 cell monolayers, examined for the presence of virus by cytopathic effect (CPE), direct immunoperoxidase (DIP) and direct immunofluorescence (DIF). Of 39 (26.0%) virus-positive specimens by CPE, 37 (24.7%) were HSV-positive by DIP and 36 (24.0%) by DIF sta...

Likert scales are routinely used in educational and psychological research as measures of constructs of interest. If sound scale development procedures are followed, the resulting scale can reliably and validly measure a construct. However, if a given scale is used to make comparisons among different populations of respondents (e.g., cultures; Riordan & Vandenberg, 1994), over time in longitudi...

OBJECTIVE To correlate disease course and complications in children with juvenile dermatomyositis (JDM) and polymyositis (JPM) with specific features of muscle pathology on biopsy. METHODS This is a retrospective cohort analysis of 59 children diagnosed with JDM or JPM between 1965 and 1998 and followed at the Cincinnati Children's Hospital Medical Center (CCHMC) for a mean duration of 7.3 ye...