Probing non-Gaussian features in the HI distribution at the epoch of reionization

The HI distribution at the epoch of reionization (EOR) is largely determined by the sizes and distribution of the ionized regions. In the scenario where the ionized regions have comoving sizes of the order of a few Mpc, the large scale statistical properties of the HI distribution are dominated by the Poisson noise of the discrete ionized regions, and it is highly non-Gaussian. We investigate the possibility of probing reionization by studying these non-Gaussian features using future radio interferometric observations of redshifted 21 cm HI radiation. We develop a formalism relating correlations between the visibilities measured at three different baselines and frequencies to the bispectrum of HI fluctuations. For visibilities at the same frequency, this signal is found to be of the same order as the two visibility correlation which probes the HI power spectrum. For visibilities at different frequencies, we find that the correlations decay within a frequency difference of ~1 MHz. This implies that it is, in principle, straightforward to extract this HI signal from various contaminants which are believed to have a continuum spectra and are expected to be correlated even at large frequency separations.Comment: 10 pages, 4 figures, Accepted to MNRAS with Minor Change

What do Women Want? Men, Women, and Job Satisfaction in the Public Service

Research in organizational behavior and public administration has long considered differences between men and women at work. Research indicates that men and women often communicate differently, prefer different approaches to organizational structure and design, and view rewards through different lenses. As women become better represented in public organizations, and at higher levels, it becomes even more important to explore sex-based differences. This paper seeks to uncover differences between men and women when it comes to determinants of job satisfaction. We use the existing literature to develop a series of hypotheses about the different factors that predict job satisfaction for the sexes. We test these hypotheses using data from a survey of health and human services managers, finding that there are more commonalities than differences when it comes to what satisfies men and women at work. Working Paper 06-3

Analysis of volume dependence of thermal expansivity for NaCl

In the present paper, a suitable model to evaluate the volume dependence of thermal expansivity α by using the reciprocal form of volume dependence of Anderson-Grüneisen parameter (δT) has been proposed. The newly developed relationship has satisfied the constraints of infinite pressure behavior, i.e., P → ∞ or V → 0. The results obtained through the present model show the consistency with the experimental data for NaCl

Protein phosphatase complement in rice: genome-wide identification and transcriptional analysis under abiotic stress conditions and reproductive development

<p>Abstract</p> <p>Background</p> <p>Protein phosphatases are the key components of a number of signaling pathways where they modulate various cellular responses. In plants, protein phosphatases constitute a large gene family and are reportedly involved in the regulation of abiotic stress responses and plant development. Recently, the whole complement of protein phosphatases has been identified in <it>Arabidopsis </it>genome. While PP2C class of serine/threonine phosphatases has been explored in rice, the whole complement of this gene family is yet to be reported.</p> <p>Results</p> <p><it>In silico </it>investigation revealed the presence of 132-protein phosphatase-coding genes in rice genome. Domain analysis and phylogenetic studies of evolutionary relationship categorized these genes into PP2A, PP2C, PTP, DSP and LMWP classes. PP2C class represents a major proportion of this gene family with 90 members. Chromosomal localization revealed their distribution on all the 12 chromosomes, with 42 genes being present on segmentally duplicated regions and 10 genes on tandemly duplicated regions of chromosomes. The expression profiles of 128 genes under salinity, cold and drought stress conditions, 11 reproductive developmental (panicle and seed) stages along with three stages of vegetative development were analyzed using microarray expression data. 46 genes were found to be differentially expressing in 3 abiotic stresses out of which 31 were up-regulated and 15 exhibited down-regulation. A total of 82 genes were found to be differentially expressing in different developmental stages. An overlapping expression pattern was found for abiotic stresses and reproductive development, wherein 8 genes were up-regulated and 7 down-regulated. Expression pattern of the 13 selected genes was validated employing real time PCR, and it was found to be in accordance with the microarray expression data for most of the genes.</p> <p>Conclusions</p> <p>Exploration of protein phosphatase gene family in rice has resulted in the identification of 132 members, which can be further divided into different classes phylogenetically. Expression profiling and analysis indicate the involvement of this large gene family in a number of signaling pathways triggered by abiotic stresses and their possible role in plant development. Our study will provide the platform from where; the expression pattern information can be transformed into molecular, cellular and biochemical characterization of members belonging to this gene family.</p

Creating Desirable Organizational Characteristics. How Organizations Create a Focus on

Abstract What are the factors that lead to desirable organizational characteristics? This article examines this question by proposing a model to explain the ability of some organizations to create a focus on results and high levels of managerial authority. The new public management literature points to these two organizational characteristics as key steps for improving public performance and providing results-based accountability. Employing a national survey of US state government health and human service agency managers we find that political support for the organization and purposeful reform efforts do lead to desirable organizational characteristics. In addition, strong internal communication fosters a focus on results, and organizational culture shapes the decision-making authority of managers

HI Fluctuations at Large Redshifts: II - the Signal Expected for GMRT

For the GMRT, we calculate the expected signal from redshifted HI emission at two frequency bands centered at 610 and 325 MHz. The study focuses on the visibility-visibility cross-correlations, proposed earlier as the optimal statistical estimator for detecting and analyzing this signal. These correlations directly probe the power spectrum of density fluctuations at the redshift where the radiation originated, and thereby provide a method for studying the large scale structures at large redshifts. We present detailed estimates of the correlations expected between the visibilities measured at different baselines and frequencies. Analytic fitting formulas representing the salient features of the expected signal are also provided. These will be useful in planning observations and deciding an optimal strategy for detecting this signal.Comment: 16 pages including 7 figures, published in JAp

Therapeutic radiological interventional procedures in hepatocellular carcinoma

Background: To improve the survival rate of patients with hepatocellular carcinoma (HCC) in whom surgery is not possible, various methods have been developed employing angiographic and percutaneous techniques. We analyzed our experience with various percutaneous therapeutic interventional techniques done for HCC in our center. Methods: Sixty-one patients with inoperable HCC (mean age 48.9 [SD 13.8] y; 47 men) were treated between January 1997 and December 2000 by transcatheter arterial chemoembolization (TACE) alone (22), TACE with percutaneous alcohol injection (PEI) (20), transcatheter arterial embolization (TAE) with steel coils and gel foam for gastrointestinal bleed (7), percutaneous radiofrequency ablation (1), percutaneous preoperative right portal vein embolization (3) and percutaneous preoperative tumor embolization to reduce blood loss at surgery (8). Results: In 42 patients treated by TACE and PEI and TACE alone, tumor necrosis was scored; over 50% necrosis was seen only after six and nine months in both treatment groups. The survival rates after six and nine months and the median survival were similar in the two groups. Of 7 cases treated with TAE with steel coils and gel foam, the gastrointestinal bleeding stopped in four; in the other three, bleeding did not stop completely although less transfusion was required. In the patient treated by radiofrequency ablation, follow-up contrast-enhanced CT did not show enhancing tumor mass. We noted left lobe enlargement after percutaneous preoperative right portal vein embolization, prior to right hepatectomy. Conclusion: In patients with HCC not amenable to surgical intervention, a variety of percutaneous therapeutic interventional techniques may be used

Unravelling seismogenesis and characterizing the unique features of two significant felt earthquakes (M > 4.0) of 2020 in the southwestern parts of the Delhi region

Two significant earthquakes (M4.6 and 4.2) occurred close to a NE–SW-trending lineament in the southwestern part of the Delhi NCR (National Capital Region) within a short time span of about 5 months in 2020. These events were located to the north of the Alwar district in Rajasthan and generated a significant ground shaking in and around Delhi. In the present study, we tried to understand a causal relationship between the events and a nearby source in the region, geologically demarcated as the lineament. We analyzed the broadband waveform data from 26 seismic stations that recorded the recent events of 03 July 2020 (M4.6) and 17 December 2020 (M4.2). Typically, the epicentral area has been devoid of significant earthquakes since the past six decades; however, a few minor events (M &lt; 4.0) have been recorded till date. Analysis of the earthquake database for two decades (2000–2022) revealed low seismicity (nearly quiescent-like situation) in ∼100 sq km area around the epicentral zone, unlike considerable seismicity along faults/lineaments close to the Delhi region. The full-waveform inversion analyses of the events indicate normal faulting with a minor strike–slip components. The source parameters, viz., source radius, stress drop, and seismic moment, were estimated to be 6 km, 166 bars, and 8.28E+15 Nm, respectively, for the 03 July 2020 event and 4 km, 138 bars, and 2.29E+15 Nm, respectively, for the 17 December 2020 event. The causative source of these events is ascertained based on the stress inversion modeling that indicated a NW–SE tensile stress corroborating well with the NE–SW-trending lineament mapped in the study region. The static Coulomb stress modeling indicated that the event which occurred on 3 July 2020 had advanced the triggering process of the event in the northeast segment of the same source that occurred on 17 December 2020. We further emphasize that the aforementioned lineament probably activated due to the regional tectonics of the study area. The causative source of these events with strike 48°, dip 86°, and rake −60° is found to be in the conformity with the local tectonics and is well-supplemented by a high stress ratio (0.70 ± 0.05) and low friction coefficient (0.5)