A new study on the emission of EM waves from large EAS

A method used in locating the core of individual cosmic ray showers is described. Using a microprocessor-based detecting system, the density distribution and hence, energy of each detected shower was estimated

Microprocessor-based single particle calibration of scintillation counter

A microprocessor-base set-up is fabricated and tested for the single particle calibration of the plastic scintillator. The single particle response of the scintillator is digitized by an A/D converter, and a 8085 A based microprocessor stores the pulse heights. The digitized information is printed. Facilities for CRT display and cassette storing and recalling are also made available

Dynamics of interacting quintessence

In this paper, we investigate coupled quintessence with scaling potential assuming specific forms of the coupling as $A$ namely, $\alpha \dot{\rho_m}$, $\beta \dot{\rho_{\phi}}$ and $\sigma (\dot{\rho_m}+\dot{\rho_{\phi}})$, and present phase space analysis for three different interacting models. We focus on the attractor solutions that can give rise to late time acceleration with $\Omega_{DE}/\Omega_{DM}$ of order unity in order to alleviate the coincidence problem.Comment: 11 pages, 3 figures, matches with the published versio

Dynamics of coupled phantom and tachyon fields

In this paper, we apply the dynamical analysis to a coupled phantom field with scaling potential taking particular forms of the coupling (linear and combination of linear), and present phase space analysis. We investigate if there exist late time accelerated scaling attractor that has the ratio of dark energy and dark matter densities of the order one. We observe that the scrutinized couplings cannot alleviate the coincidence problem, however acquire stable late time accelerated solutions. We also discuss coupled tachyon field with inverse square potential assuming linear coupling.Comment: 16 pages, 6 caption figures, 3 Tables, text, figure are added, matches with the published versio

Charter Schools and the Road to College Readiness: The Effects on College Preparation, Attendance and Choice

The analysis here focuses on Boston's charter high schools. For the purpose of this report, an analysis of high schools is both a necessity and a virtue. It is necessary to study high schools because most students applying to charters in earlier grades are not yet old enough to generate data on postsecondary outcomes. Charter high schools are also of substantial policy interest: a growing body of research argues that high school may be too late for cost-effective human capital interventions. Indeed, impact analyses of interventions for urban youth have mostly generated disappointing results.This report is interested in ascertaining whether charter schools, which in Massachusetts are largely budget-neutral, can have a substantial impact on the life course of affected students. The set of schools studied here comes from an earlier investigation of the effects of charter attendance in Boston on test scores.The high schools from the earlier study, which enroll the bulk of charter high school students in Boston, generate statistically and socially significant gains on state assessments in the 10th grade. This report questions whether these gains are sustained

Isgur-Wise function in a QCD potential model with coulombic potential as perturbation

We study heavy light mesons in a QCD inspired quark model with the Cornell potential$-\frac{4\alpha_{S}}{3r}+br+c$. Here we consider the linear term $br$ as the parent and $-\frac{4\alpha_{S}}{3r}+c$ i.e.the Coloumbic part as the perturbation.The linear parent leads to Airy function as the unperturbed wavefunction. We then use the Dalgarno method of perturbation theory to obtain the total wavefunction corrected upto first order with Coulombic peice as the perturbation.With these wavefunctions, we study the Isgur-Wise function and calculate its slope and curvature.Comment: paper has been modified in Airy functions calculation upto o(r^3

A Compact Instrument for the Measurement of Surface Tension of Liquids

An Instrument for the measurement of surface tension of liquids by a null method is described. The method of balancing the downward force of surface tension on the edge of a thin gloss plate by the upward hydrostatic pressure of the liquid is used. The instrument is quite compact, handy and sensitive and can be used for rapid measurement on a number of samples

A Review on Beneficiation Prospect of Some of the Graphite Deposits of Palamu District of Bihar

Graphite constitutes one of the important minerals for the manufacture of special types of refractory materials. In nature it occurs both in crystalline as well as amorphous forms. It is reported to occur in almost every State of India. In Bihar economic deposits of graphite are confined to the district of Palamu only with some minor occurences in Monghyr and Ranchi districts. G.S.I has located some important workable deposits whose estimated total reserves amount to about 16 lakhs tonnes upto 20 meters depth. These depsits are poorer in grade but sometimes the fixed carbon content is of the order of 50% F.C. A few customary processing plants have also been put up by some private parties

Lymphotoxin is an autocrine growth factor for Epstein-Barr virus-infected B cell lines.

Because human lymphotoxin (LT) was originally isolated from a lymphoblastoid cell line, we investigated the role of this molecule in three newly established Epstein-Barr virus (EBV)-infected human B cell lines. These lines were derived from acute lymphoblastic leukemia (Z-6), myelodysplastic syndrome (Z-43), and acute myelogenous leukemia (Z-55) patients who had a prior EBV infection. Each lymphoblastoid cell line had a karyotype that was different from that of the original parent leukemic cells, and all expressed B cell, but not T cell or myeloid surface markers. In all three lines, rearranged immunoglobulin heavy chain joining region (JH) bands were found, and the presence of EBV DNA was confirmed by Southern blotting. Z-6, Z-43, and Z-55 cell lines constitutively produced 192, 48, and 78 U/ml LT, respectively, as assessed by a cytotoxicity assay and antibody neutralization. Levels of tumor necrosis factor (TNF) were undetectable. Scatchard analysis revealed that all the cell lines expressed high-affinity TNF/LT receptors with receptor densities of 4197, 1258, and 1209 sites/cell on Z-6, Z-43, and Z-55, respectively. Furthermore, labeled TNF binding could be reversed by both unlabeled TNF, as well as by LT. Studies with p60 and p80 receptor-specific antibodies revealed that the three lines expressed primarily the p80 form of the TNF receptor. When studied in a clonogenic assay, exogenous LT stimulated proliferation of all three cell lines in a dose-dependent fashion at concentrations ranging from 25 to 500 U/ml. Similar results were obtained with [3H]TdR incorporation. Monoclonal anti-LT neutralizing antibodies at concentrations of 25-500 U/ml inhibited cellular multiplication in a dose-dependent manner. It is interesting that in spite of a common receptor, TNF (1,000 U/ml) had no direct effect on Z-55 cell growth, whereas it partially reversed the stimulatory effect of exogenous LT. In addition, TNF inhibited Z-6 and Z-43 cell proliferation, and its suppressive effect was reversed by exogenous LT. Both p80 and p60 forms of soluble TNF receptors suppressed the lymphoblastoid cell line proliferation and their inhibitory effect was partially reversed by LT. Our data suggest that (a) LT is an autocrine growth factor for EBV-transformed lymphoblastoid B cell lines; and (b) anti-LT antibodies, soluble TNF/LT receptors, and TNF itself can suppress the growth of lymphoblastoid cells, probably by modulating or competing with LT.(ABSTRACT TRUNCATED AT 400 WORDS

Antifungals, arthropods and antifungal resistance prevention: lessons from ecological interactions

Arthropods can produce a wide range of antifungal compounds, including specialist proteins, cuticular products, venoms and haemolymphs. In spite of this, many arthropod taxa, particularly eusocial insects, make use of additional antifungal compounds derived from their mutualistic association with microbes. Because multiple taxa have evolved such mutualisms, it must be assumed that, under certain ecological circumstances, natural selection has favoured them over those relying upon endogenous antifungal compound production. Further, such associations have been shown to persist versus specific pathogenic fungal antagonists for more than 50 million years, suggesting that compounds employed have retained efficacy in spite of the pathogens' capacity to develop resistance. We provide a brief overview of antifungal compounds in the arthropods' armoury, proposing a conceptual model to suggest why their use remains so successful. Fundamental concepts embedded within such a model may suggest strategies by which to reduce the rise of antifungal resistance within the clinical milieu