Is a step in the primordial spectral index favored by CMB data ?

A sudden small change in the second derivative of the inflaton potential can result in a universal local feature in the spectrum of primordial perturbations generated during inflation. The exact solution describing this feature \cite{minu} is characterized by a step in the spectral index modulated by characteristic oscillations and results in a large running of the spectral index localized over a few e-folds of scale. In this paper we confront this step-like feature with the 5 year WMAP results and demonstrate that it provides a better fit to this data than a featureless initial spectrum. If such a feature exists at all, then it should lie at sufficiently large scales $k_0 \lesssim 0.003 {\rm Mpc}^{-1}$ corresponding to $l \lesssim 40$. The sign of the effect is shown to correspond to the negative running of $n_s$ localized near this scale. This feature could arise as a result of a `mini-waterfall'-type fast second order phase transition experienced by an auxiliary heavy field during inflation, in a model similar to hybrid inflation (though for a different choice of parameters). If this is the case, then the auxiliary field should be positively coupled to the inflaton.Comment: Several new results, figures and enhanced discussion. Main conclusions unchanged. Matches the final version to be published in JCA

New Universal Local Feature in the Inflationary Perturbation Spectrum

A model is developed in which the inflaton potential experiences a sudden small change in its second derivative (the effective mass of the inflaton). An exact treatment demonstrates that the resulting density perturbation has a quasi-flat power spectrum with a break in its slope (a step in n_s). The step in the spectral index is modulated by characteristic oscillations and results in large running of the spectral index localised over a few e-folds of scales. A field-theoretic model giving rise to such behaviour of the inflationary potential is based on a fast phase transition experienced by a second scalar field weakly coupled to the inflaton. Such a transition is similar to that which terminates inflation in the hybrid inflationary scenario. This scenario suggests that the observed running of the spectral index in the WMAP data may be caused by a fast second order phase transition which occurred during inflation.Comment: 4 figures, matches the published versio

Literacy and Livelihood of Women Migrant Construction Workers: An Analytical Study

Migration is a demographic process that has been chronicled across world history. Even though various reasons have accelerated this process over the years, the dominant trend in internal migration during the 20th century has been the movement from rural to urban areas. The casual and unskilled workers who shift from one region to another, offering their services on a temporary or seasonal basis are considered migrant labourers. The 21st century has witnessed problems related to migration intensifying. Migrant labourers face hostility from local populations posing a great challenge for governments to maintain the welfare of these people. Unfavorable social, economic, and cultural conditions make their lives even worse. As a result, migrant workers are frequently deprived of their basic rights and benefits which they otherwise deserve. This results in mass exploitation of the migrant community. Hence, the present study explores the problems and challenges faced by migrant construction workers, specifically women, and their impact on various aspects of their lives. The study has been conducted among 200 women migrant construction workers in North Bangalore as per the convenience sampling method, and the collected data was analyzed with the help of statistical tools such as Factor analysis, Chi-Square Analysis, one-way ANOVA, Weighted Average Rank

Elevated levels of serum adenosine deaminase in type 2 diabetes mellitus patients

Background: Diabetes Mellitus (DM) is a metabolic disorder characterized by an absolute or relative deficiency of insulin and insulin resistance or both. Adenosine deaminase (ADA) is an enzyme, that catalyses the irreversible hydrolytic deamination of adenosine to uric acid. Since ADA activity is associated with T-lymphocyte activity and insulin resistance, in the present study, we measured serum ADA activity in type 2 Diabetes mellitus (T2DM) patients to evaluate the relationship between serum ADA activities with glycemic status.Methods: A total of 100 T2DM patients and controls were recruited for the study. Estimation of fasting plasma glucose (FPG), postprandial plasma glucose (PPG), HbA1c and fasting lipid profile was done. Serum ADA level was estimated by Colorimetric method. Statistical analysis of data was performed using the SPSS version 15.Results: ADA level was significantly higher (p<0.001) in patients with T2DM (45.5+4.6 U/L) than controls. A significant positive correlation was observed between serum ADA and HbA1c (r=0.585), FPG (r=0.495), PPG (0.387) and serum triglycerides (r=0.375) among subjects with T2DM but not among non-diabetic controls.Conclusions: In the present study, serum ADA activity in T2DM patients has been increased. High ADA activity reduces the glucose uptake into cells; therefore, insulin resistance is related to ADA activity

From the Spectrum to Inflation: A Second Order Inverse Formula for the General Slow-Roll Spectrum

We invert the second order, single field, general slow-roll formula for the power spectrum, to obtain a second order formula for inflationary parameters in terms of the primordial power spectrum

N,N′-(2,2′-Dithiodi-o-phenyl­ene)bis­(furan-2-carboxamide)

The reaction of 2,2′-dithio­bis(benzenamine) with furan-2-carbonyl chloride produced the bis-amide title compound, C22H16N2O4S2, which, in the crystal, formed a helix; the structure consists of two planar furanoylbenzenamines related by an improper rotation of 96.3° about the S—S bond. The N-furanoylbenzenamine units are planar (maximum deviations = 0.316 and 0.132 Å). Each electron-deficient acyl­furan stacks (centroid–centroid separations of the two pairs of π–π stacked aromatic rings are 3.918 and 3.953 Å) with the electron-rich benzenamine of the other N-furan­oyl­benzenamine unit, leading to a spiral structure. The conformation is stabilized by two bifurcated intramolecular N—H⋯(O,S) interactions

Variation in superconducting transition temperature due to tetragonal domains in two-dimensionally doped SrTiO₃

Strontium titanate is a low-temperature, non-Bardeen-Cooper-Schrieffer superconductor that superconducts to carrier concentrations lower than in any other system and exhibits avoided ferroelectricity at low temperatures. Neither the mechanism of superconductivity in strontium titanate nor the importance of the structure and dielectric properties for the superconductivity are well understood. We studied the effects of twin structure on superconductivity in a 5.5-nm-thick layer of niobium-doped SrTiO$_{3}$ embedded in undoped SrTiO$_{3}$. We used a scanning superconducting quantum interference device susceptometer to image the local diamagnetic response of the sample as a function of temperature. We observed regions that exhibited a superconducting transition temperature $T_{c}$ $\gtrsim$ 10% higher than the temperature at which the sample was fully superconducting. The pattern of these regions varied spatially in a manner characteristic of structural twin domains. Our results emphasize that the anisotropic dielectric properties of SrTiO$_{3}$ are important for its superconductivity, and need to be considered in any theory of the mechanism of the superconductivity.Comment: 14 pages, 11 figures, Supplemental Information available at http://stanford.edu/group/moler/papers/Noad_STOsuperconductivity_SI.pd

Topological structure and dynamics of three-dimensional active nematics.

Topological structures are effective descriptors of the nonequilibrium dynamics of diverse many-body systems. For example, motile, point-like topological defects capture the salient features of two-dimensional active liquid crystals composed of energy-consuming anisotropic units. We dispersed force-generating microtubule bundles in a passive colloidal liquid crystal to form a three-dimensional active nematic. Light-sheet microscopy revealed the temporal evolution of the millimeter-scale structure of these active nematics with single-bundle resolution. The primary topological excitations are extended, charge-neutral disclination loops that undergo complex dynamics and recombination events. Our work suggests a framework for analyzing the nonequilibrium dynamics of bulk anisotropic systems as diverse as driven complex fluids, active metamaterials, biological tissues, and collections of robots or organisms