Occurrence of Streptomyces aurantiacus in Mangroves of Bhitarkanika

Thirteen strains of Streptomyces were isolated from phyllosphere of nine mangrove tree species found in Bhitarkanika mangrove ecosystem of Orissa. According to physiological, biochemical data, all 13 of the isolates were taxonomically identified to the genus Streptomyces as aurantiacus species. All strains are grayish, spirals and forming amorphous colony. Almost all utilized araginose, produced H2S, resistant towards rifampicin and penicillin, urea except few strains. However, they exhibited different extracellular activity like phosphate solubilization, lipase and L asparaginase production. This is a unique report from this mangrove ecosystem as far as Streptomyces occurrence is concerned

Occurrence and incidence of foot rot disease on fenugreek caused by Fusarium moniliforme in Rohilkhand region of Uttar Pradesh, India

Pathological studies were carried out in Rohilkhand region during the crop season 2013-14 to assess the pathogenic disease incidence of foot rot of fenugreek (Trigonella foenum-graecum Linn.) caused by Fusarium moniliforme. A total of 75 fields were surveyed during the crop period at monthly interval during germination, vegetative, flowering and fruiting stages in five different localities of Rohilkhand region. The foot-rot disease of fenugreek was found in all fields (Bareilly, Baheri, Pilibhit, Budaun and Meerganj) selected for the study. Monthly occurrence of disease incidence of foot rot ranged from 44-58%. Maximum disease incidence was recorded in the month of Oct. (58%) followed by September (57%) and November (56%). January exhibited the lowest incidence (45%) of pathogenic disease. However, foot rot symptoms developed at early stage of plant growth and persisted up to the end of the crop

Current-Induced Spin Polarization in Gallium Nitride

Electrically generated spin polarization is probed directly in bulk GaN using Kerr rotation spectroscopy. A series of n-type GaN epilayers are grown in the wurtzite phase both by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD) with a variety of doping densities chosen to broadly modulate the transverse spin lifetime, T2*. The spin polarization is characterized as a function of electrical excitation energy over a range of temperatures. Despite weak spin-orbit interactions in GaN, a current-induced spin polarization (CISP) is observed in the material at temperatures of up to 200 K.Comment: 16 pages, 3 figure

Weakly Z symmetric manifolds

We introduce a new kind of Riemannian manifold that includes weakly-, pseudo- and pseudo projective- Ricci symmetric manifolds. The manifold is defined through a generalization of the so called Z tensor; it is named "weakly Z symmetric" and denoted by (WZS)_n. If the Z tensor is singular we give conditions for the existence of a proper concircular vector. For non singular Z tensor, we study the closedness property of the associated covectors and give sufficient conditions for the existence of a proper concircular vector in the conformally harmonic case, and the general form of the Ricci tensor. For conformally flat (WZS)_n manifolds, we derive the local form of the metric tensor.Comment: 13 page

Long-term occupational exposure to DDT

Blood serum of twenty workers occupationally exposed to DDT for an average duration of 14 years was analysed for organochlorine pesticides by gas-liquid chromatography with an electron capture detector. Significant levels of BHC, p,p'-DDT, p,p'-DDD and p,p-DDE were detected. A higher incidence of total DDT equivalent, about 10 times, was observed in DDT exposed workers when compared with a comparable sample of unexposed persons from the general population. Levels of DDT in serum of occupationally exposed workers were more than the permitted level of 200 ppb. The daily intake was computed to be about 10 mg/man/day as against 0.25 mg-the acceptable daily intale. Abnormal nerve conduction was encountered in a few cases of DDT sprayers. No significant correlation was observed between the total DDT equivalent in serum and duration of occupational exposure in workers. Levels of BHC in controls was 2.3 times the level in exposed workers, possibly due to induction of hepatic drug metabolising enzymes by high levels of DDT in the latter group. Findings are discussed in the light of existing knowledge of the bio-chemical effects evoked due to residual intoxication of DDT during occupational exposure

Synthesis, spectral, thermal, kinetic and antibacterial studies of transition metal complexes with benzimidazolyl-2-hydrazones of o-hydroxyacetophenone, o-hydroxybenzophenone and o-vanillin

A novel series of Schiff base metal complexes of the type [M(L)2].nH2O, where L= 2-(α-methylsalicylidenehydrazino) benzimidazole (L1), 2-(α-phenylsalicylidenehydrazino)benzimidazole (L2),  2-(o-vanillinidenehydrazino)benzimidazole (L3), M = Cu(II), Co(II), Ni(II) and Zn(II), have been synthesized and characterized. The results are in consistent with tridentate chelation of ligand with azomethine nitrogen, ring nitrogen and a deprotonated phenolic oxygen atom. All these compounds have been screened for their antibacterial activities against B. subtilis, B. stearothermophilus, E. coli and S. typhi.               KEY WORDS: Schiff base, Metal complexes, Spectral studies, Thermal studies, Kinetic studies, Antibacterial studies Bull. Chem. Soc. Ethiop. 2018, 32(3), 437-450. DOI: https://dx.doi.org/10.4314/bcse.v32i3.

Indexed Absolute Summability Factor of Improper Integrals

In this paper, we have defined the summability for improper integrals and established a theorem on indexed absolute Cesaro summability factors of improper integral under sufficient conditions. Some auxiliary results (well known) have also been deduced from the main result under suitable conditions

Hardness of porous nanocrystalline Co-Ni electrodeposits

The Hall-Petch relationship can fail when the grain size is below a critical value of tens of nanometres. This occurs particularly for coatings having porous surfaces. In this study, electrodeposited nanostructured Co-Ni coatings from four different nickel electroplating baths having grain sizes in the range of 11-23 nm have been investigated. The finest grain size, approximately 11 nm, was obtained from a coating developed from the nickel sulphate bath. The Co-Ni coatings have a mixed face centred cubic and hexagonal close-packed structures with varying surface morphologies and different porosities. A cluster-pore mixture model has been proposed by considering no contribution from pores to the hardness. As the porosity effect was taken into consideration, the calculated pore-free hardness is in agreement with the ordinary Hall-Petch relationship even when the grain size is reduced to 11 nm for the Co-Ni coatings with 77±2 at% cobalt. The present model was applied to other porous nanocrystalline coatings, and the Hall-Petch relationship was maintained. © 2013 The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht. © KIM and Springer