Gamow-Teller transitions and deformation in the proton-neutron random phase approximation

We investigate reliability of Gamow-Teller transition strengths computed in the proton-neutron random phase approximation, comparing with exact results from diagonalization in full $0\hbar\omega$ shell-model spaces. By allowing the Hartree-Fock state to be deformed, we obtain good results for a wide variety of nuclides, even though we do not project onto good angular momentum. We suggest that deformation is as important or more so than pairing for Gamow-Teller transitions.Comment: 8 pages, 5 figures; added references, clarified discussion with regards to stabilit

Confinement of fractional excitations in a triangular lattice antiferromagnet

High-resolution neutron and THz spectroscopies are used to study the magnetic excitation spectrum of Cs$_2$CoBr$_4$, a distorted-triangular-lattice antiferromagnet with nearly XY-type anisotropy. What was previously thought of as a broad excitation continuum [Phys. Rev. Lett. 129, 087201 (2022)] is shown to be a series of dispersive bound states reminiscent of "Zeeman ladders" in quasi-one-dimensional Ising systems. At wave vectors where inter-chain interactions cancel at the Mean Field level, they can indeed be interpreted as bound finite-width kinks in individual chains. Elsewhere in the Brillouin zone their true two-dimensional structure and propagation are revealed.Comment: 11 pages, 8 figure

Raft-dependent endocytosis of autocrine motility factor is phosphatidylinositol-3-kinase-dependent in breast carcinoma cells

Autocrine motility factor (AMF) is internalized via a receptor-mediated, dynamin-dependent, cholesterol-sensitive raft pathway to the smooth endoplasmic reticulum that is negatively regulated by caveolin-1. Expression of AMF and its receptor (AMFR) is associated with tumor progression and malignancy; however, the extent to which the raft-dependent uptake of AMF is tumor cell-specific has yet to be addressed. By Western blot and cell surface fluorescence-activated cell sorter (FACS) analysis, AMFR expression is increased in tumorigenic MCF7 and metastatic MDA-231 and MDA-435 breast cancer cell lines relative to dysplastic MCF10A mammary epithelial cells. AMF uptake, determined by FACS measurement of protease-insensitive internalized fluorescein-conjugated AMF, was increased in MCF7 and MDA-435 cells relative to MCF-10A and caveolin-1-expressing MDA-231 cells. Uptake of fluorescein-conjugated AMF was dynamin-dependent, methyl-beta-cyclodextrin- and genistein-sensitive, reduced upon overexpression of caveolin-1 in MDA-435 cells, and increased upon short hairpin RNA reduction of caveolin-1 in MDA-231 cells. Tissue microarray analysis of invasive primary human breast carcinomas showed that AMFR expression had no impact on survival but did correlate significantly with expression of phospho-Akt. Phospho-Akt expression was increased in AMF-internalizing MCF7 and MDA-435 breast carcinoma cells. AMF uptake in these cells was reduced by phosphatidylinositol 3-kinase inhibition but not by regulators of macropinocytosis such as amiloride, phorbol ester, or actin cytoskeleton disruption by cytochalasin D. The raft-dependent endocytosis of AMF therefore follows a distinct phosphatidylinositol 3-kinase-dependent pathway that is up-regulated in more aggressive tumor cells

Pharmacokinetic parameters of meloxicam after its oral administration in goat

Aim: The objective of the present study was to find out the levels of analgesic drug meloxicam in the blood plasma of young goats. The drug was given to them through oral route. Data was used to elucidate the Pharmacokinetic determinants of the drug which were employed to arrive at the dose schedule and frequency of the drug in goats. Materials and Methods: Elaborate pharmacokinetic research of the drug meloxicam was done on 18 to 24 months old, five adult male local goats (Capra hircus) of Assam weighing 20 to 25 kg.The drug was given orally at the dose rate of 0.35 mg/kg at the Goat Rearing farm, Guwahati, Assam. Analysis of blood was done by high performance liquid chromatography (HPLC) system. Results: The mean values of area under curve (AUC) and mean area under curve (AUMC) were 3137.488 ± 125.3749 µg.min/ml and 4650460 ± 380892.4744 µg.min2/ml respectively .The mean peak plasma level of meloxicam was 1.972 ± 0.0477 µg/ml at 600 min. The mean values of elimination half life (t1/2β) and absorption half life (t1/2Ka) were 693±0.00 min and 170.6 ± 17.0076 min respectively. The mean values of volume of distribution (Vd) and mean residence time (MRT) were 0.114 ± 0.0156 L/kg and 1472.264 ± 63.336 min respectively. The mean value of Tmax was found to be 497 ± 19.8040 min. Following single oral administration the minimum effective therapeutic concentration or minimum effective plasma concentration of meloxicam was detectable up to 1200 min. The bioavailibity (F) of the drug was 80.5 ± 10.0150%. Conclusion: These pharmacokinetic determinants were used to determine the frequency and dose schedule of meloxicam in goats. The minimum effective concentration of the drug is 0.7 µg/ml in plasma. To maintain this, an initial loading dose of 0.5 mg/kg body weight should be followed by a maintenance dose of 0.4 mg/kg body weight/10 hour

Vulnerability to Climate Change: Adaptation Strategies and Layers of Resilience - Climatic Trends in Bangladesh. Research Report No. 10

This study was conducted as part of the Asian Development Bank (ADB) funded project “Vulnerability to Climate Change: Adaptation Strategies and layers of resilience”. Long term climatic datasets were analyzed for Bangladesh and for specific study locations in the country. The report gives general climatic characteristics of the country and trend analysis of important climatic parameters such as temperature, rainfall, etc. Mean annual maximum and minimum temperature showed a rising trend from 1971 to date. During the last decade, there is a reduction in the number of potential rainy days with respect to the 40 year normal in the majority of meteorological stations across the country. However, the annual total rainfall showed an increasing trend in the flood and drought prone areas of the country. The numbers of instances of extreme events, ie, floods, has been high during the last decade

Massive stars as thermonuclear reactors and their explosions following core collapse

Nuclear reactions transform atomic nuclei inside stars. This is the process of stellar nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars are reviewed. How stars manage to burn their fuel so slowly most of the time are also considered. Stellar thermonuclear reactions involving protons in hydrostatic burning are discussed first. Then I discuss triple alpha reactions in the helium burning stage. Carbon and oxygen survive in red giant stars because of the nuclear structure of oxygen and neon. Further nuclear burning of carbon, neon, oxygen and silicon in quiescent conditions are discussed next. In the subsequent core-collapse phase, neutronization due to electron capture from the top of the Fermi sea in a degenerate core takes place. The expected signal of neutrinos from a nearby supernova is calculated. The supernova often explodes inside a dense circumstellar medium, which is established due to the progenitor star losing its outermost envelope in a stellar wind or mass transfer in a binary system. The nature of the circumstellar medium and the ejecta of the supernova and their dynamics are revealed by observations in the optical, IR, radio, and X-ray bands, and I discuss some of these observations and their interpretations.Comment: To be published in " Principles and Perspectives in Cosmochemistry" Lecture Notes on Kodai School on Synthesis of Elements in Stars; ed. by Aruna Goswami & Eswar Reddy, Springer Verlag, 2009. Contains 21 figure

News Consumption and Anti-Western Narratives in Russia:A Case Study of University Students

This essay investigates the relationship between habits of news consumption and geographical imaginations in Russia. It uses results from a survey of students at a Moscow university to demonstrate an association between the news sources used by respondents and their acceptance of the Russian authorities’ narrative about the West. Students who used at least one state-aligned news source were inclined to express greater agreement with the official (negative) narrative about the West than students who did not use any state-aligned news sources. However, some of the Russian authorities’ anti-Western claims resonated strongly even amongst the non-users of state-aligned sources