Motivated by recent neutron, X-ray absorption and resonant scattering experiments, we revisit the electronic structure of V2O3. We propose a model in which S=1 V 3+ ions are coupled in the vertical V-V pairs forming two-fold orbitally degenerate configurations with S=2. Ferro-orbital ordering of the V-V pairs gives a description which is consistent with all experiments in the antiferromagnetic insulating phase.PACS Nos : 71.30.+h, 75.50.Ee Although the metal-insulator transition in V 2 O 3 has long been studied as a classic , the detailed electronic structure remains open. Recently new experimental techniques have been applied but these have not resolved the issue. Rather they have reopened the long standing controversy between an S = 1 model without an orbital degeneracy and the S = 1/2 orbitally degenerate model of Castellani et al. [4]. In this Letter we propose a new model for the AF-ordered insulating (AFI) phase based on the molecular orbitals of the caxis V-V pairs, which combines features of both existing models and which reconciles the apparently conflicting experiments supporting each. FIG. 1. Corundum structure of V2O3.The V-ions (solid circles) are arranged in V-V pairs along the c-axis (face-sharing octahedra) and a honeycomb lattice in the other directions (edge-sharing octahedra).The V-ions in the corundum structure of V 2 O 3 sit in a O-octahedron with a small trigonal distortion causing a small splitting in the non-bonding t 2g -shell between the a 1g -orbital oriented along the c-axis and doublet planar e g -orbitals (see Fig. 1). In their early work, Castellani et al. proposed that one electron of the 3d 2 V 3+ -ion entered a spin singlet covalent a 1g -bond in the V-V pair while the remaining electron was in the e g -doublet. Orbital ordering of these e g -doublets allowed them to explain the unusual magnetic structure of the AFI-phase with inequivalent n.n. exchange constants in the a − b plane (2 antiferromagnetic, 1 ferromagnetic) [5][6][7]. Paolasini et al. [8] interpreted their recent resonant x-ray experiments as a confirmation of this orbital ordering. On the other hand the polarized soft x-ray experiments by Park et al.[9] showed a coexistence of both (e g e g ) and (e g a 1g ) configurations in roughly equal amounts and these led Ezhov et al.[10] to argue for a S = 1 model with a (e g e g ) configuration and no orbital degeneracy. This is favored by the atomic Hund's Rule whose strength, as they point out, is not screened in the crystal. The differing planar exchange constants they attribute to the monoclinic distortion in the AFI-phase. Yet general considerations of the phase diagram [11] and NMR investigations [12] all point towards to the presence of an orbital degeneracy.Here we take a different approach to the AFI-phase and start from an atomic limit but consider first the V-V pairs, since the intersite a 1g -hopping matrix elements are the largest [4]. Keeping a strong Hund's Rule coupling, as proposed by Ezhov et al., leads us to molecular orbitals for a V-V pair consistin...

The Holstein-Primakoff transformation is generalized to develop a quantum flavor wave theory for spin systems with orbital degeneracy. Elementary excitations of ordered ground states consist of spin, orbital , and spinorbital waves. Spin and spin-orbital waves couple to each other due to orbital anisotropy and Hund's rule, resulting in new modes observable by inelastic

Aim:This prospective randomized clinical study (1) investigated the prevalence of post-obturation pain after single visit root canal treatment and (2) evaluated the influence of factors affecting the pain experience.Materials and Methods:One thousand three hundred and twenty eight (1328) patients were included in this study. Conventional single visit root canal treatment was carried out. The chemicomechanical preparation of root canals was done by a rotary protaper system with a combination of hand instruments. Post-operative pain was recorded by each patient by using visual analogue scale in well-defined categories at three time intervals, 12 h, 24 h, and 48 h. The data were analyzed using Fisher's exact test.Results:The prevalence of post-obturation pain (severe) within 48 h after treatment was 4% (n = 54) but less as compared to the pain experienced after 12 h (9%) and 24 h (8.6%). The factors that significantly influenced post-obturation pain experience were: Age (Fishers exact test = 46.387, P = 0.0), gender (Fishers exact test = 23.730, P = 0.0), arch (Fishers exact test = 11.710, P = 0.001), and presence of pre-operative pain (Fishers exact test = 67.456, P = 0.0).Conclusion:The presence of post-operative pain was low (4%). The important prognostic determinants of post-obturation pain were: Old age, female, mandibular teeth, and presence of pre-operative pain. The vital condition of the tooth does not affect the intensity and frequency of post-obturation pain.

We study antiferromagnetic spin chains with unfrustrated long-range interactions that decay as power laws with exponent ␤, using the spin-wave approximation. We find for sufficiently large spin S that the Neel order is stable at Tϭ0 for ␤Ͻ3, and survives up to a finite Neel temperature for ␤Ͻ2, validating the spin-wave approach in these regimes. We estimate the critical values of S and T for the Neel order to be stable. The spin-wave spectra are found to be gapless but have nonlinear momentum dependence at long wavelength, which is responsible for the suppression of quantum and thermal fluctuations and stabilizing the Neel state. We also show that for ␤р1 and for a large but finite-size system size L, the excitation gap of the system approaches zero slower than L Ϫ1 , a behavior that is in contrast to the Lieb-Schultz-Mattis theorem.

BackgroundKrishna Tulsi, a member of Lamiaceae family, is a herb well known for its spiritual, religious and medicinal importance in India. The common name of this plant is ‘Tulsi’ (or ‘Tulasi’ or ‘Thulasi’) and is considered sacred by Hindus. We present the draft genome of Ocimum tenuiflurum L (subtype Krishna Tulsi) in this report. The paired-end and mate-pair sequence libraries were generated for the whole genome sequenced with the Illumina Hiseq 1000, resulting in an assembled genome of 374 Mb, with a genome coverage of 61 % (612 Mb estimated genome size). We have also studied transcriptomes (RNA-Seq) of two subtypes of O. tenuiflorum, Krishna and Rama Tulsi and report the relative expression of genes in both the varieties.ResultsThe pathways leading to the production of medicinally-important specialized metabolites have been studied in detail, in relation to similar pathways in Arabidopsis thaliana and other plants. Expression levels of anthocyanin biosynthesis-related genes in leaf samples of Krishna Tulsi were observed to be relatively high, explaining the purple colouration of Krishna Tulsi leaves. The expression of six important genes identified from genome data were validated by performing q-RT-PCR in different tissues of five different species, which shows the high extent of urosolic acid-producing genes in young leaves of the Rama subtype. In addition, the presence of eugenol and ursolic acid, implied as potential drugs in the cure of many diseases including cancer was confirmed using mass spectrometry.ConclusionsThe availability of the whole genome of O.tenuiflorum and our sequence analysis suggests that small amino acid changes at the functional sites of genes involved in metabolite synthesis pathways confer special medicinal properties to this herb.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0562-x) contains supplementary material, which is available to authorized users.

No abstract

Building on the gains of the National Health Mission, India’s Reproductive, Maternal, Newborn, Child and Adolescent Health (RMNCH+A) Strategy, launched in 2013, was a milestone in the country’s health planning. The strategy recognised the interdependence of RMNCH+A Interventions across the life stages and adopted a comprehensive approach to address inequitable distribution of healthcare services for the vulnerable population groups and in poor-performing geographies of the country. Based on innovative approaches and management reforms, like selection of poor-performing districts, prioritisation of high-impact RMNCH+A healthcare interventions, engagement of development partners and institutionalising a concurrent monitoring system the strategy strived to improve efficiency and effectiveness within the public healthcare delivery system of the country. 184 High Priority Districts were identified across the country on a defined set of indicators for implementation of critical RMNCH+A Interventions and a dedicated institutional framework comprising National and State RMNCH+A Units and District Level Monitors supported by the development partners was established to provide technical support to the state and district health departments. Health facilities based on case load and available services across the High Priority Districts were prioritised for strengthening and were monitored by an RMNCH+A Supportive Supervision mechanism to track progress and generate evidence to facilitate actions for strengthening ongoing interventions. The strategy helped develop an integrated systems-based approach to address public health challenges through a comprehensive framework, defined priorities and robust partnerships with the partner agencies. However, lack of a robust monitoring and evaluation framework and sub-optimal focus on social determinants of health possibly limited its overall impact and ability to sustain improvements. Guided by the learnings and limitations, the Government of India has now designed the ‘Aspirational Districts Program’ to holistically address health challenges in poor-performing districts within the overall sociocultural domain to ensure inclusive and sustained improvements.

Quasi-one-dimensional antiferromagnetic ͑AF͒ quantum spin systems show a wide range of interesting phenomena such as the spin-Peierls transition and disorder driven long-range ordering. While there is no magnetic long-range order in strictly one-dimensional systems, in real systems some amount of interchain coupling is always present and AF long-range order may appear below a Néel ordering temperature T N . We study the effect of bond randomness on Néel ordering in weakly coupled random AF Sϭ1/2 chains, both with and without dimerization ͑or spin-Peierls order͒. We use the real space renormalization group method to tackle the intrachain couplings, and a mean-field approximation to treat the interchain coupling. We show that in the nondimerized chain, disorder ͑represented by bond randomness͒ enhances the Néel order parameter; in the dimerized chain which shows no magnetic ordering in the weak interchain coupling limit without randomness, disorder can actually lead to long range order. Thus disorder is shown to lead to, or enhance the tendency toward long range order, providing another example of the order-by-disorder phenomenon. We make a qualitative comparison of our results with the observed phenomenon of doping induced long-range ordering in quasi-one-dimensional spin systems such as CuGeO 3 . Quasi-one-dimensional quantum spin systems have been under intense theoretical and experimental investigation over the past few decades.1 These systems show a wide range of interesting and unexpected phenomenon such as the spinPeierls transition and disorder driven long-range ordering.2-11 In strictly one-dimensional systems, there is no long-range magnetic order due to strong quantum and thermal fluctuations. However in real systems, such as CuGeO 3 , KCuF 3 , or Sr 2 CuO 3 some amount of interchain coupling is always present. 3,12,13 In these cases magnetic long range order may appear below a Néel ordering temperature T N . In this work we study the effect of disorder on long range ordering in weakly coupled spin chains. We show that disorder leads to, or enhances the tendency toward long-range order, providing another example of the order-by-disorder phenomenon that has received considerable attention in recent years.14 The disorder driven long-range ordering seen here is purely quantum mechanical in origin, as opposed to being thermally driven.14 The specific example that we bear in mind in our study is the interesting phenomenon of doping driven long range ordering observed in the spin-Peierls material CuGeO 3 . In this system the Cu ions form an effective one-dimensional ͑1D͒ antiferromagnetic ͑AF͒ spin-1/2 chain with weak interchain coupling. This is the first inorganic system to show the spinPeierls transition.3 Surprisingly, while the pure system has no magnetic order in the ground state, doping the system with a very small amount of impurities, such as Si for Ge ͑Refs. 4 -10͒ or Zn, Ni, or Mg for Cu, 4,5,8,11 leads to the appearance of AF long range order ͑LRO͒ that may coexist with spinPeierls order ͑or dimer...