Interstellar reddening in the galaxy

Objective prism spectra obtained with the 16/24/60-inch Schmidt telescope have been used for an investigation of the wavelength dependence of interstellar absorption in the spectral range from 8000A to 3450A, in a region of 30 square degrees in Cygnus centred on (20ʰ15ᵐ, 38 °). Monochromatic magnitude differences have been measured at 24 wavelengths for 28 pairs of stars down to magnitude V = 10ᵐ.0.The mean reddening curves derived separately for 0- and early B-type stars do not differ by more than 5 per cent. The reddening law in the direction of Cygnus does not change by more than 3 per cent over distances out to 2 - 2.5 kpc. The intrinsic r.m.s. dispersion about the mean reddening curve is less than 3 per cent.Since there is no significant intrinsic dispersion, no significant distance dependence and no significant difference between the reddening curves for 0- and B- stars, all the available observational data in the Cygnus region have been used to give a weighted mean reddening curve with a mean standard error of ±0.8 per cent. Over the observed wavelength range the reddening curve can be represented by two straight lines, intersecting at about 4300A

Three colour photometry of galactic clusters NGC 2422, NGC 2423 and NGC 2437

The work is described in two parts:Part I contains a discussion of the work on the interpretation of the Hertzsprung-Russell diagram with regard to problems of stellar evolution .Part II describes the three-colour studies of the southern galactic clusters NGC 2422, NGC 2423, and NGC 2437. The colour excesses and distances, corrected for absorption, are: NGC 2422, 0.06 and 480 parsecs; NGC 2423, 0 and 450 parsecs; NGC 2437, 0.16, 1450 parsecs

Peritonitis by Leclercia adecarboxylata in a patient with continuous ambulatory peritoneal dialysis: the first case report from India

Peritonitis is a major complication in patients on continuous ambulatory peritoneal dialysis (CAPD), which is increasingly being caused by rare, saprophytic microorganisms. We present a case having CAPD admitted in our hospital that came with complaint of pain abdomen and cloudy peritoneal effluent, from which pure culture of Leclercia adecarboxylata had been isolated L. adecarboxylata is a rarely reported gram negative human pathogen, very easily misdiagnosed as Escherichia coli

Genetic Characterisation of Colistin Resistant Klebsiella pneumoniae Clinical Isolates From North India

BackgroundIncreasing use of colistin has led to the world-wide emergence of mobile colistin resistant gene (mcr). The present study aimed to identify and characterise mcr and other drug-resistant genes in colistin resistant Klebsiella pneumoniae clinical isolates.MethodsTwenty-two colistin resistant K. pneumoniae were analysed for mcr and other drug-resistant genes, efflux pumps, and virulence genes, and for their biofilm forming ability. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were performed for all mcr-1 positive isolates. S1-PFGE and Southern hybridisation were performed for localisation of mcr-1 and blaNDM.ResultsNineteen colistin resistant K. pneumoniae harboured mcr-1 and 3 had mgrB disruption. All isolates harboured blaOXA-48-type and ESBL genes; eight strains (five with mcr-1 and three with mgrB disruption) co-harboured blaNDM. Efflux pumps genes AcrAB and mdtK were detected in all 22 and tol-C in 21 isolates. Virulence-related genes entB and irp-1 were detected in all 22, mrkD in 20, and fimH-1 in 18 isolates; 11 isolates were strong biofilm producers. PFGE clustered mcr-1 positive isolates into eight groups based on ≥90% similarity; MLST revealed diverse sequence types, predominant being ST-15 (n = 4) and ST-16 (n = 4). Both mcr-1 and blaNDM were localised on plasmid and chromosome; mcr-1 was present on IncFII type and blaNDM on IncFIB and IncA/C type plasmids.ConclusionsColistin resistance in K. pneumoniae was predominantly mediated by mcr-1. Co-existence of colistin, carbapenem, and other drug-resistant genes along with efflux pumps indicates towards enormous genomic plasticity in K. pneumoniae with ability to emerge as super-spreader of drug-resistance

The rph1 Gene Is a Common Contributor to the Evolution of Phosphine Resistance in Independent Field Isolates of Rhyzopertha Dominica

Phosphine is the only economically viable fumigant for routine control of insect pests of stored food products, but its continued use is now threatened by the world-wide emergence of high-level resistance in key pest species. Phosphine has a unique mode of action relative to well-characterised contact pesticides. Similarly, the selective pressures that lead to resistance against field sprays differ dramatically from those encountered during fumigation. The consequences of these differences have not been investigated adequately. We determine the genetic basis of phosphine resistance in Rhyzopertha dominica strains collected from New South Wales and South Australia and compare this with resistance in a previously characterised strain from Queensland. The resistance levels range from 225 and 100 times the baseline response of a sensitive reference strain. Moreover, molecular and phenotypic data indicate that high-level resistance was derived independently in each of the three widely separated geographical regions. Despite the independent origins, resistance was due to two interacting genes in each instance. Furthermore, complementation analysis reveals that all three strains contain an incompletely recessive resistance allele of the autosomal rph1 resistance gene. This is particularly noteworthy as a resistance allele at rph1 was previously proposed to be a necessary first step in the evolution of high-level resistance. Despite the capacity of phosphine to disrupt a wide range of enzymes and biological processes, it is remarkable that the initial step in the selection of resistance is so similar in isolated outbreaks