Cabibbo-suppressed non-leptonic B- and D-decays involving tensor mesons

The Cabibbo-suppressed non-leptonic decays of B (and D) mesons to final states involving tensor mesons are computed using the non-relativistic quark model of Isgur-Scora-Grinstein-Wise with the factorization hypothesis. We find that some of these B decay modes, as B --> (K^*, D^*)D^*_2, can have branching ratios as large as 6 x 10^{-5} which seems to be at the reach of future B factories.Comment: Latex, 11 pages, to appear in Phys. Rev.

Evidence for genetic divergence in ribosomal RNA genes in mycobacteria

DNA was isolated from Mycobacterium phlei and from M. smegmatis. Each DNA sample was restricted with endonucleases, the fragments were separated by agarose gel electrophoresis and transferred to nitrocellulose film. Fragments of DNA containing rRNA sequences were identified by means of 125I-labelled rRNA of M. phlei or of M. smegmatis. The distributions of restriction endonuclease sites within the rRNA gene(s) and flanking sequences were found to be characteristic for each of the two species. Hybridizations with heterologous probes indicate that although M. phlei rRNA and M. smegmatis rRNA share regions of sequence homology, they are probably not identical in primary structure. The results suggest that the rRNA genes might prove to be useful taxonomic markers for mycobacteria

In Vitro Evaluation of Ethanolic Extracts of Ageratum conyzoides

In vitro efficacy of ethanolic extracts obtained from the aerial parts of Ageratum conyzoides and Artemisia absinthium was assessed on Rhipicephalus microplus using adult immersion test (AIT). Five concentrations of the extract (1.25%, 2.5%, 5%, 10%, and 20%) with three replications for each concentration were used in the bioassay. In AIT, the maximum mortality was recorded as 40% and 66.7% at 20% concentration for A. conyzoides and A. absinthium, respectively. Acaricidal activity was found to be higher in the extract of A. absinthium with LC50 and LC95 values of 11.2% and 61.7%, respectively. Egg mass weight of the live ticks treated with different concentrations of the extracts was significantly (P<0.05) lower than that of control ticks; consequently, the reproductive index and oviposition values of the treated ticks were reduced significantly (P<0.05). The A. conyzoides inhibited 90% hatching of eggs at the 20% concentration, whereas A. absinthium showed 100% inhibition at 5%, 10%, and 20% concentrations. The results show that A. absinthium has better acaricidal properties than A. conyzoides and could be useful in controlling R. microplus

Non-leptonic B decays involving tensor mesons

Two-body non-leptonic decays of B mesons into PT and VT modes are calculated using the non-relativistic quark model of Isgur et al.. The predictions obtained for $B \to \pi D^*_2, \rho D_2^*$ are a factor of $3\sim 5$ below present experimental upper limits. Interesting patterns are obtained for ratios of B decays involving mesons with different spin excitations and their relevance for additional tests of forms factor models are briefly discussed.Comment: 11 pages, Latex, to appear in Phys. Rev.

Mutations in RpoB Gene and Their Association with Rifampicin-resistance Levels in Clinical Isolates of Mycobacterium Tuberculosis

Present study was aimed to identify most frequent mutations in rpoB gene region and to evaluate the association between mutations in rpoB gene and resistance levels to Rifampicin in clinical isolates of Mycobacterium tuberculosis of different geographical regions of India. A total of 100 clinical isolates of Mycobacterium tuberculosis were included in this study. Drug susceptibility testing against first line anti-tuberculosis drugs was performed on LJ medium by conventional minimal inhibitory concentration (MIC) method and the mutation(s) in rpoB gene of M. tuberculosis isolates were analyzed by sequencing method. Of the 100 M. tuberculosis isolates, 31 (31.0%) and 18 (18.0%) were found resistant and susceptible for all four first-line anti-tuberculosis drugs. The genetic mutations were observed in 96% (72/75) rifampicin-resistant M. tuberculosis isolates, while 4% (3/75) of rifampicin-resistant isolates did not have any mutation in rpoB gene. The mutation TCG531TTG (Ser531Leu) was found as most common and frequent mutation in 69.3% (52/75) of rifampicin-resistant isolates of M. tuberculosis with MIC level (≥ 512mg/l). The mutation at codon 511 was associated with low degree (128mg/l) of rifampicin-resistance, deletions at codons 514-516 or substitution at codon 516 were found to be associated with moderate degree (256mg/l) of rifampicin-resistance and mutations at codon 526, 531 were associated with the high degree (512mg/l) of rifampicin-resistance in M. tuberculosis isolates of Indian origin. The findings of this study will be useful for the development of raid and more specific indigenous molecular tools for the early diagnosis of multidrug-resistant tuberculosis in the country

Characterization of catalase by micro-immunoprecipitation in tissue-derived cells of Mycobacterium lepraemurium TMC 1701

Cell-free extracts of tissue-derived cells of Mycobacterium lepraemurium TMC 1701 have been found to have mycobacterial catalase which is of the T type. Immunological distance measurements of this catalase against three reference mycobacterial systems, as determined by a micro-immunoprecipitation technique, showed that catalase from M. lepraemurium TMC 1701 is most closely related to that of Mycobacterium avium but is still distinct from it. In this respect, this strain is uniquely positioned between Mycobacterium tuberculosis and M. avium

Terenska istraživanja bakterijske etiologije pobačaja u nomadskih ovaca i koza u sjeverozapadnim brdovitim područjima Indije

A field study on the bacterial etiology of abortions among sheep and goats having migratory practices in the northwest hilly states of India was carried out. A total of 203 flocks were investigated. Abortion outbreaks occurred in 51 flocks and sporadic abortions occurred in 114 flocks. Vaginal swabs from aborted sheep and goats were collected and processed for isolation of bacterial agents from 37 flocks with abortion outbreaks and 56 flocks with sporadic abortions. Bacteria known to cause abortions were identified in 30 flocks with abortion outbreaks including Chlamydophila spp. (17 flocks), Brucella melitensis (4 flocks), Listeria monocytogenes (8 flocks), and one Salmonella Dublin. L. ivanovii was also isolated from sheep in one of the flocks with L. monocytogenes. No specific causes of abortion were identified in flocks having sporadic abortions. The results also show that Chlamydophila spp. abortions are more likely to occur in goats than in sheep and that Brucella abortions occur more often in sheep.U radu su provedena terenska istraživanja bakterijske etiologije pobačaja u ovaca i koza kod nomadskog načina stočarenja u sjevero-zapadnim brdovitim državama Indije. Pretražena su 203 stada. Pobačaji su se masovno javljali u 51, a sporadično u 114 stada. Vaginalni obrisci uzeti su od ovaca i koza iz 37 stada s masovnom pojavom pobačaja te iz 56 stada sa sporadičnim pobačajima. Bakterije poznate kao uzročnici pobačaja dokazane su u 30 stada s masovnom pojavom pobačaja. Tako je dokazana Chlamydophila spp. (u 17 stada), Brucella melitensis (u 4 stada), Listeria monocytogenes (u 8 stada), a u jednom stadu Salmonella Dublin. L. Ivanovii izdvojena je iz ovaca u jednom stadu zajedno s vrstom L. monocytogenes. Specifični uzročnici pobačaja nisu bili dokazani u stadima sa sporadičnom pojavom pobačaja. Rezultati su pokazali da su se klamidijski pobačaji češće javljali u koza nego u ovaca, a oni uzrokovani brucelama češće u ovaca

Hadronic decays of B involving a tensor meson through a b→cb \to c transition

We re-analyze hadronic decays of B mesons to a pseudoscalar (P) and a tensor meson (T), or a vector meson (V) and a tensor meson, through a $b \to c$ transition. We discuss possible large uncertainties to branching ratios (BR's) of the relevant modes, mainly arising from uncertainties to the hadronic form factors for the $B \to T$ transition. The BR's and CP asymmetries for $B \to PT$ and VT decays are then calculated by using the form factors given in the ISGW2 model (the improved version of the original Isgur-Scora-Grinstein-Wise (ISGW) model). We find that the estimated BR's of many modes are increased by an order of magnitude, compared to the previous results calculated within the ISGW model.Comment: 22 pages, LaTex; minor clarifications included; to appear in Phys. Rev.