A Measure for the Adiabaticity of Quantum Transitions

We construct a measure for the adiabaticity of quantum transitions in an arbitrary basis. Small deviations from nearly completely adiabatic quantum dynamics can be easily quantified through integrals of non-adiabatic couplings between instantaneous eigenstates, as is usually done. In contrast, the situation is more involved in generic quantum dynamics that may be only partially adiabatic and when transitions between non-eigenstates are of interest. Targeting the latter case, we demonstrate with several examples, how the measure is able to distinguish transitions between basis states that occur due to the adiabatic change of a populated energy eigenstate from those that occur due to beating between several such eigenstates.Comment: 7 pages, 4 figures, comments are welcome

Multiscale Modelling Of The Stress Singularity At A Mode I Crack Tip

Direct modelling technique is used to study stresses at the tip of a mode I crack where domain of the material microstructure is explicitly discretised and represented by finite elements. Two cases of internal (at crack faces) and external uniform loading are considered. A multiscale asymptotic model accounting for both the external boundaries and the non-singular stresses at the crack tip are used to analyse the numerical results. It is shown that the parameters (coefficients) of the expansion of the stress concentration at the crack tip can be recovered for both cases of loading from the simulated stress distribution ahead of the crack tip. Applicability of this technique is validated by recovering the parameters for a wider range of heterogeneous material properties

Conserved roles of Osiris genes in insect development, polymorphism, and protection

Much of the variation among insects is derived from the different ways that chitin has been moulded to form rigid structures, both internal and external. In this study, we identify a highly conserved expression pattern in an insect-only gene family, the Osiris genes, that is essential for development, but also plays a significant role in phenotypic plasticity and in immunity/toxicity responses. The majority of Osiris genes exist in a highly syntenic cluster, and the cluster itself appears to have arisen very early in the evolution of insects. We used developmental gene expression in the fruit fly, Drosophila melanogaster, the bumble bee, Bombus terrestris, the harvester ant, Pogonomyrmex barbatus, and the wood ant, Formica exsecta, to compare patterns of Osiris gene expression both during development and between alternate caste phenotypes in the polymorphic social insects. Developmental gene expression of Osiris genes is highly conserved across species and correlated with gene location and evolutionary history. The social insect castes are highly divergent in pupal Osiris gene expression. Sets of co-expressed genes that include Osiris genes are enriched in gene ontology terms related to chitin/cuticle and peptidase activity. Osiris genes are essential for cuticle formation in both embryos and pupae, and genes co-expressed with Osiris genes affect wing development. Additionally, Osiris genes and those co-expressed seem to play a conserved role in insect toxicology defences and digestion. Given their role in development, plasticity, and protection, we propose that the Osiris genes play a central role in insect adaptive evolution.Peer reviewe

On the response of the equatorial and low latitude ionospheric regions in the Indian sector to the large magnetic disturbance of 29 October 2003

The present paper investigates the response of the equatorial and low latitude ionosphere over the Indian longitudes to the events on 29 October 2003 using ionosonde data at Trivandrum (8.5° N (0.5° N geomagnetic), 77° E) and SHAR (13.7° N (5.7° N geomagnetic), 80.2° E), groundbased magnetometer data from Trivandrum and Total Electron Content (TEC) derived from GPS data at the locations of Ahmedabad (23° N (15° N geomagnetic), 72° E), Jodhpur (26.3° N (18.3° N geomagnetic), 73° E) and Delhi (28° N (20° N geomagnetic), 77° E). Following the storm sudden commencement, the TEC at all the three stations showed an overall enhancement in association with episodes of interplanetary electric field penetration. Interestingly, real ionospheric height profiles derived using the ionosonde data at both Trivandrum and SHAR showed significant short-term excursions and recoveries. In the post noon sector, these features are more pronounced over SHAR, an off equatorial station, than those over Trivandrum indicating the increased effects of neutral winds

Bianchi type-II cosmological model: some remarks

Within the framework of Bianchi type-II (BII) cosmological model the behavior of matter distribution has been considered. It is shown that the non-zero off-diagonal component of Einstein tensor implies some severe restriction on the choice of matter distribution. In particular for a locally rotationally symmetric Bianchi type-II (LRS BII) space-time it is proved that the matter distribution should be strictly isotropic if the corresponding matter field possesses only non-zero diagonal components of the energy-momentum tensor.Comment: 3 page

Renal Transplantation and Pregnancy

Introduction: Although pregnancy after kidney transplantation is feasible, complications are relatively common and this needs to be considered in patient counseling and clinical decision making.Review: Fertility generally returns after renal transplantation. Approximately 74% of pregnancies in kidney transplant recipients end successfully in life births. Published reports suggest that pregnancy has no adverse affects on graft survival although patients with higher pre-pregnancy serum creatinine have a trend toward increased post-pregnancy serum creatinine. There is, however, a significantly increased risk of preeclampsia, gestational diabetes, cesarean section and preterm delivery compared to the general population. Almost half life births are preterm, and low birth weight is very common. Immunosuppressive medications are required to be continued during pregnancy in transplant recipients to prevent graft rejection, except for  sirolimus and mycophenolate mofetil (MMF) which are contraindicated during pregnancy. The incidence of birth defects in the live born is similar to the general population, except for pregnancies exposed to MMF which have a high incidence of birth defects. Every female in the reproductive age group should be counseled regarding pregnancy including the potential risks to the graft, to the mother and to the child. Timing pregnancy should be based upon whether graft function is optimal, but the general recommendation is to wait one year post transplantation before conception.Conclusion: Pregnancy in renal transplant patients should be planned with combined care from surgeons, nephrologists, obstetricians, pediatricians and dietitians which offers the best chance of a favorable outcome in the mother and the fetus

Seasonal dependence of the "forecast parameter" based on the EIA characteristics for the prediction of Equatorial Spread F (ESF)

In an earlier study, Thampi et al. (2006) have shown that the strength and asymmetry of Equatorial Ionization Anomaly (EIA), obtained well ahead of the onset time of Equatorial Spread F (ESF) have a definite role on the subsequent ESF activity, and a new "forecast parameter" has been identified for the prediction of ESF. This paper presents the observations of EIA strength and asymmetry from the Indian longitudes during the period from August 2005-March 2007. These observations are made using the line of sight Total Electron Content (TEC) measured by a ground-based beacon receiver located at Trivandrum (8.5° N, 77° E, 0.5° N dip lat) in India. It is seen that the seasonal variability of EIA strength and asymmetry are manifested in the latitudinal gradients obtained using the relative TEC measurements. As a consequence, the "forecast parameter" also displays a definite seasonal pattern. The seasonal variability of the EIA strength and asymmetry, and the "forecast parameter" are discussed in the present paper and a critical value for has been identified for each month/season. The likely "skill factor" of the new parameter is assessed using the data for a total of 122 days, and it is seen that when the estimated value of the "forecast parameter" exceeds the critical value, the ESF is seen to occur on more than 95% of cases