In Escherichia coli, the gcvB gene encodes a nontranslated RNA (referred to as GcvB) that regulates OppA and DppA, two periplasmic binding proteins for the oligopeptide and dipeptide transport systems. An additional regulatory target of GcvB, sstT, was found by microarray analysis of RNA isolated from a wild-type strain and a gcvB deletion strain grown to mid-log phase in Luria-Bertani broth. T...

The Luria-Delbrück mutation model has been mathematically formulated in a number of ways. This review article examines four most important formulations, focusing on important practical issues closely linked with the distribution of the number of mutants. These issues include the probability generating functions, moments (cumulants), computational methods and asymptotics. This review emphasizes ...

In Escherichia coli, the gcvB gene encodes a small non-translated RNA that regulates several genes involved in transport of amino acids and peptides (including sstT, oppA and dppA). Microarray analysis identified cycA as an additional regulatory target of GcvB. The cycA gene encodes a permease for the transport of glycine, d-alanine, d-serine and d-cycloserine. RT-PCR confirmed that GcvB and th...

Fluctuation analysis is the standard experimental method for measuring mutation rates in micro-organisms. The appearance of mutants is classically described by a Luria-Delbrück distribution composed of two parameters: the number of mutations per culture (m) and the differential growth rate between mutant and wild-type cells (b). A precise estimation of these two parameters is a prerequisite to ...

Luria-Nebraska Neuro-psychological Battery, is now an established tool to assess brain damage in recent years. This test battery has been reported to be very useful to find out functional organization of the brain. The biological basis of psychiatry is also now well explained. The present study is directed towards the neuro-psychological functioning of schizophrenic disorder, and the findings a...

Passage through new hosts or new tissues is a widely used method for altering the properties of viruses. In some instances selection of spontaneous mutants has been demonstrated to be the mechanism causing the variation (Luria, 1945). Nonhereditary mechanisms sometimes have been postulated, but since no such case has been analyzed sufficiently, it is often assumed that selection of mutants is t...

10 volumes of Luria–Bertani (LB) medium containing Tet and Kn and grown to saturation. To begin the third positive selection, a 25 ml GMML culture containing Tet, Kn, and 1 mM pIF, pAF, pCF, or OAY was inoculated with cells from the negative screen (100 μl, pelleted and resuspended in GMML). After incubation for 3 h at 37°C, Cm was added to a final concentration of 75 μg/ml, and cells were grow...

Neuropsychological functioning of epileptic patients is emerging as an interesting area of research among clinician. There is sufficient evidence suggesting cognitive deficits among epileptics. No specific rehabilitation planning was prepared in this regard. The planning for rehabilitation can be prepared if a comprehensive functional organization of the brain of epileptics can be identified. T...