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.

Magnetism of fine particles of Kondo lattices, obtained by high-energy ball-milling

Despite intense research in the field of strongly correlated electron behavior for the past few decades, there has been very little effort to understand this phenomenon in nano particles of the Kondo lattices. In this article, we review the results of our investigation on the fine particles (less than 1 micron) of some of the alloys obtained by high-energy ball-milling to bring out that this synthetic method paves a way to study strong electron correlations in nanocrystals of such alloys. We primarily focus on the alloys of the series, CeRu(2-x)Rh(x)Si2, lying at different positions in Doniach's magnetic phase diagram. While CeRu2Si2, a bulk paramagnet, appears to become magnetic (of a glassy type) below about 8 K in fine particle form, in CeRh2Si2, an antiferromagnet (T_N= 36 K) in bulk form, magnetism is destroyed (at least down to 0.5 K) in fine particles. In the alloy, CeRu(0.8)Rh(1.2)Si2, at the quantum critical point, no long range magnetic ordering is foundComment: SCES201

Development of Fish Hydrolysate (Bind-Add+) incorporated extruded pellets and its performance in Tilapia (Oreochromis niloticus) feeding trial

Fish hydrolysate (FH) based Bind-Add+ is a emulsion type feed binder cum additive which contains un-denatured proteins and calcium is capable of reasonable level of gelatinization and contribute to the binding properties which is seen from water absorptive capacity, buoyancy, bulk density and water stability characteristics during extrusion pellet production.. Bind-Add+ has good amount of bio-available primary nutrients, secondary nutrients, micro nutrients, anti-oxidants and pro-biotic in a soluble liquid form and most suitable as additive or feed supplement. Tilapia (Oreochromis niloticus) feeding trial indicate that growth rate and feed utilization efficiency in Bind-Add+ incorporated diets increases significantly in comparison to controlled diet

Neutrino Oscillations via the Bulk

We investigate the possibility that the large mixing of neutrinos is induced by their large coupling to a five-dimensional bulk neutrino. In the strong coupling limit the model is exactly soluble. It gives rise to an oscillation amplitude whose squared-mass difference is independent of the channel, thus making it impossible to explain both the solar and the atmospheric neutrino oscillations simultaneously.Comment: References added and rearranged, typos corrected, a graph added, and more detailed explanations provided. To appear in Physical Review

Minimal SUSY SO(10) model and predictions for neutrino mixings and leptonic CP violation

We discuss a minimal Supersymmetric SO(10) model where B-L symmetry is broken by a {\bf 126} dimensional Higgs multiplet which also contributes to fermion masses in conjunction with a {\bf 10} dimensional superfield. This minimal Higgs choice provides a partial unification of neutrino flavor structure with that of quarks and has been shown to predict all three neutrino mixing angles and the solar mass splitting in agreement with observations, provided one uses the type II seesaw formula for neutrino masses. In this paper we generalize this analysis to include arbitrary CP phases in couplings and vevs. We find that (i) the predictions for neutrino mixings are similar with $U_{e3}\simeq 0.18$ as before and other parameters in a somewhat bigger range and (ii) that to first order in the quark mixing parameter $\lambda$ (the Cabibbo angle), the leptonic mixing matrix is CP conserving. We also find that in the absence of any higher dimensional contributions to fermion masses, the CKM phase is different from that of the standard model implying that there must be new contributions to quark CP violation from the supersymmetry breaking sector. Inclusion of higher dimensional terms however allows the standard model CKM phase to be maintained.Comment: 22 pages, 6 figure

On 'Light' Fermions and Proton Stability in 'Big Divisor' D3/D7 Swiss Cheese Phenomenology

Building up on our earlier work [1,2], we show the possibility of generating "light" fermion mass scales of MeV-GeV range (possibly related to first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-$brane restricted to (in principle) stacks of fluxed D7-branes wrapping the "big" divisor \Sigma_B. This part of the paper is an expanded version of the latter half of section 3 of a published short invited review [3] written up by one of the authors [AM]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, as well as estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 10^{61} years. Based on GLSM calculations in [1] for obtaining the geometric Kaehler potential for the "big divisor", using further the Donaldson's algorithm, we also briefly discuss in the first of the two appendices, obtaining a metric for the Swiss-Cheese Calabi-Yau used, that becomes Ricci flat in the large volume limit.Comment: v2: 1+25 pages, Title modified and text thoroughly expanded including a brief discussion on obtaining Ricci-flat Swiss Cheese Calabi-Yau metrics using the Donaldson's algorithm, references added, to appear in EPJ

Genetic population structure of the malaria vector Anopheles baimaii in north-east India using mitochondrial DNA

<p>Abstract</p> <p>Background</p> <p><it>Anopheles baimaii </it>is a primary vector of human malaria in the forest settings of Southeast Asia including the north-eastern region of India. Here, the genetic population structure and the basic population genetic parameters of <it>An. baimaii </it>in north-east India were estimated using DNA sequences of the mitochondrial cytochrome oxidase sub unit II (COII) gene.</p> <p>Methods</p> <p><it>Anopheles baimaii </it>were collected from 26 geo-referenced locations across the seven north-east Indian states and the COII gene was sequenced from 176 individuals across these sites. Fifty-seven COII sequences of <it>An. baimaii </it>from six locations in Bangladesh, Myanmar and Thailand from a previous study were added to this dataset. Altogether, 233 sequences were grouped into eight population groups, to facilitate analyses of genetic diversity, population structure and population history.</p> <p>Results</p> <p>A star-shaped median joining haplotype network, unimodal mismatch distribution and significantly negative neutrality tests indicated population expansion in <it>An. baimaii </it>with the start of expansion estimated to be ~0.243 million years before present (MYBP) in north-east India. The populations of <it>An. baimaii </it>from north-east India had the highest haplotype and nucleotide diversity with all other populations having a subset of this diversity, likely as the result of range expansion from north-east India. The north-east Indian populations were genetically distinct from those in Bangladesh, Myanmar and Thailand, indicating that mountains, such as the Arakan mountain range between north-east India and Myanmar, are a significant barrier to gene flow. Within north-east India, there was no genetic differentiation among populations with the exception of the Central 2 population in the Barail hills area that was significantly differentiated from other populations.</p> <p>Conclusions</p> <p>The high genetic distinctiveness of the Central 2 population in the Barail hills area of the north-east India should be confirmed and its epidemiological significance further investigated. The lack of genetic population structure in the other north-east Indian populations likely reflects large population sizes of <it>An. baimaii </it>that, historically, were able to disperse through continuous forest habitats in the north-east India. Additional markers and analytical approaches are required to determine if recent deforestation is now preventing ongoing gene flow. Until such information is acquired, <it>An. baimaii </it>in north-east India should be treated as a single unit for the implementation of vector control measures.</p

Neutrino anomalies and large extra dimensions

Theories with large extra dimensions can generate small neutrino masses when the standard model neutrinos are coupled to singlet fermions propagating in higher dimensions. The couplings can also generate mass splittings and mixings among the flavour neutrinos in the brane. We systematically study the minimal scenario involving only one singlet bulk fermion coupling weakly to the flavour neutrinos. We explore the neutrino mass structures in the brane that can potentially account for the atmospheric, solar and LSND anomalies simultaneously in a natural way. We demonstrate that in the absence of a priori mixings among the SM neutrinos, it is not possible to reconcile all these anomalies. The presence of some structure in the mass matrix of the SM neutrinos can solve this problem. This is exemplified by the Zee model, which when embedded in extra dimensions in a minimal way can account for all the neutrino anomalies.Comment: 23 Revtex pages with 2 eps figure

Lowering solar mixing angle in inverted hierarchy without charged lepton corrections

In the present work, the inverted hierarchical neutrino mass model which is characterised by opposite CP parity in the first two mass eigenvalues $(m_1,-m_2,m_3)$, is studied in order to lower the predicted value of solar mixing angle $\tan^2\theta_{12}$, from the tri-bimaximal mixing (TBM), without sacrificing the conditions of maximal atmospheric mixing angle and zero reactor angle. The present attempt is different from the earlier approach where the correction from the charged lepton mass matrix is included in the leptonic mixing matrix to lower the prediction on solar mixing angle. The lowering of the solar mixing angle without charged lepton correction, can be obtained through the variation of the input value of a flavour twister term present in the texture of neutrino mass matrix having a 2-3 symmetry. The present analysis agrees with the latest experimental bounds on neutrino mass parameters and also represents an important result on the survival of the inverted hierarchical neutrino mass models having opposite CP parity in the first two eigenvalues.Comment: 10 pages, two figures. Accepted for publication in Journal of Physics G:Nuclear and Particle Physic

On the taxonomic validity of Boiga whitakeri Ganesh et al., 2021 with new insights on Boiga dightoni (Boulenger, 1894) (Reptilia: Squamata: Colubridae)

Colour polymorphism has been previously reported in several colubrid snakes including Boiga spp. In this paper, we report colour variations within the poorly known southern Indian Boiga dightoni, provide the first molecular data for this species, from two localities (including the type locality) and compare them with data from other congeners. Additionally, we provide detailed dentition and hemipenis descriptions for B. dightoni. Molecular data for B. dightoni show very little difference (0.2–0.4% 16S; 0.9–1.2% cyt b) to the recently described Boiga whitakeri, also from southern India. We have re-examined and present new information on the pholidosis of the type specimens of B. whitakeri and reconsider its taxonomic status. On the basis of molecular data and overlapping morphological characteristics, we argue that Boiga whitakeri and Boiga dightoni are conspecific, and place B. whitakeri under the subjective synonymy of the latter. Furthermore, we show that colour polymorphism in B. dightoni is a gender-independent character and that both colour morphs are found in high as well as low elevations and partly in sympatry. A revised key to the Boiga ceylonensis complex is provided