Detecting gravitational lensing cosmic shear from samples of several galaxies using two-dimensional spectral imaging

Studies of weak gravitational lensing by large-scale structures require the measurement of the distortions introduced to the shapes of distant galaxies at the few percent level by anisotropic light deflection along the line of sight. To detect this signal on 1-10 arcmin scales in a particular field, accurate measurements of the correlations between the shapes of order 1000-10000 galaxies are required. This large-scale averaging is required to accommodate the unknown intrinsic shapes of the background galaxies, even with careful removal of systematic effects. Here an alternative is discussed. If it is possible to measure accurately the detailed dynamical structure of the background galaxies, in particular rotating disks, then it should be possible to measure directly the cosmic shear distortion, as it generally leads to a non-self-consistent rotation curve. Narrow spectral lines and excellent two-dimensional spatial resolution are required. The ideal lines and telescope are CO rotational transitions and the Atacama Large Millimeter Array (ALMA) respectively.Comment: 12 pages, 4 figures, Expected to appear in ApJ Letters Vol. 570, 10 May 2002. Replaced with final proof version correcting minor typo

HI and OH absorption at z=0.89

We report on WSRT observations of HI and OH absorption at z=0.885 towards the radio lens PKS 1830-21, mm wave transitions of several molecular species have already been observed at this redshift. At mm wavelengths the source structure is dominated by two extremely compact components, the northeast (NE) and southwest (SW) components. At lower frequencies the continuum emission is much more extended and there is also a broad Einstein ring connecting the NE and SW components. This means that the HI and OH spectra sample a much larger region of the absorber than the mm wave spectra. The HI spectrum that we obtain is asymmetric, with a peak at -147 km/s with respect to the main molecular line redshift of z=0.88582. Weak mm wave molecular absorption has also been detected towards the NE component at this same velocity. The HI absorption, however, covers a total velocity width of 300 km/sec, i.e. including velocities well to the red of molecular features suggesting that it is spatially widespread. In OH we detect both the 1667 and the 1665 MHz transitions. The OH spectrum has a velocity width comparable to that of the HI spectrum, suggesting that it too is widespread in the absorber. The lack of a prominent HI peak in the spectrum at the velocity corresponding to the SW component, suggests that the galaxy responsible for the absorption at z=0.885 has a central molecular disk many kpc in size, and that HI is deficient in this central region. Our observations are sensitive to the large scale kinematics of the absorber, and to first order the implied dynamical mass is consistent with the lens models of Nair et. al. (1993).Comment: 4 pages, 3 figure

A Low Cost Remote Sensing System Using PC and Stereo Equipment

A system using a personal computer, speaker, and a microphone is used to detect objects, and make crude measurements using a carrier modulated by a pseudorandom noise (PN) code. This system can be constructed using a personal computer and audio equipment commonly found in the laboratory or at home, or more sophisticated equipment that can be purchased at reasonable cost. We demonstrate its value as an instructional tool for teaching concepts of remote sensing and digital signal processing.Comment: Accepted for publication in American Journal of Physic

On The Center Sets and Center Numbers of Some Graph Classes

For a set $S$ of vertices and the vertex $v$ in a connected graph $G$, $\displaystyle\max_{x \in S}d(x,v)$ is called the $S$-eccentricity of $v$ in $G$. The set of vertices with minimum $S$-eccentricity is called the $S$-center of $G$. Any set $A$ of vertices of $G$ such that $A$ is an $S$-center for some set $S$ of vertices of $G$ is called a center set. We identify the center sets of certain classes of graphs namely, Block graphs, $K_{m,n}$, $K_n-e$, wheel graphs, odd cycles and symmetric even graphs and enumerate them for many of these graph classes. We also introduce the concept of center number which is defined as the number of distinct center sets of a graph and determine the center number of some graph classes

PHYSICOCHEMICAL AND PHYTOCHEMICAL ANALYSIS OF BUTEA MONOSPERMA (LAM.) FLOWER

Introduction: Butea monosperma, a deciduous tree belonging to the family Faboideae, is found growing in many parts of India. All the parts of plant are highly medicinal with its mention in different systems of medicine. Several review works have summarized the potential efficiency of this plant.Objective: The present work attempts to evaluate the physicochemical and preliminary phytochemical studies on the flowers of Butea monosperma Koen. Ex Roxb, family Fabaceae. The work is done for pharmacognostic standardization and authentication of flowers of Butea monosperma.Methods: The herbal standardization was carried out on the basis of organoleptic properties, physical characteristics, and physico-chemical properties. Physicochemical parameters including ash values, extractive values, loss on drying, foreign matter were evaluated.Results: Powder is yellowish brown, velvety in texture, bitter in taste and smells chocolaty. The Loss on Drying at 105 c, total ash and acid insoluble ash were found to be 5.39%, 7.82%, 1.07%, w/w respectively. Ethanol and water soluble extractive values (hot)were 14.21%, 22%w/w respectively. The extracts were subjected to preliminary phytochemical screening and the results certified the presence of alkaloids, phenols, flavonoids, triterpinoids, steroids, carbohydrates, proteins and saponins in alcohol and aqueous extracts of flower.Conclusion: These studies provided referential information for correct identification and standardization of this plant material

Blade manipulators in turbulent channel flow

We report here the results of a series of careful experiments in turbulent channel flow, using various configurations of blade manipulators suggested as optimal in earlier boundary layer studies. The mass flow in the channel could be held constant to better than 0.1%, and the uncertainties in pressure loss measurements were less than 0.1 mm of water; it was therefore possible to make accurate estimates of the global effects of blade manipulation of a kind that are difficult in boundary layer flows. The flow was fully developed at the station where the blades were mounted, and always relaxed to the same state sufficiently far downstream. It is found that, for a given mass flow, the pressure drop to any station downstream is always higher in the manipulated than in the unmanipulated flow, demonstrating that none of the blade manipulators tried reduces net duct losses. However the net increase in duct losses is less than the drag of the blade even in laminar flow, showing that there is a net reduction in the total skin friction drag experienced by the duct, but this relief is only about 20% of the manipulator drag at most

Awareness about adverse drug reaction monitoring and pharmacovigilance among final year medical students in tertiary care teaching hospital in Andhra Pradesh: a cross sectional study

Background: Adverse drug reaction (ADR) is an unwanted, undesirable effect of a drug that occurs during clinical use. ADRs will occur daily in health care institutions and can unfavourably affect a patient's quality of life, frequently causing considerable morbidity and mortality. Pharmacovigilance is defined as the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other drug-related problem.Methods: It was a non-interventional study was done among hundred final year medical students at Kurnool Medical College, Kurnool, Andhra Pradesh. The study instrument was a predesigned questionnaire was structured by following the precedence, which was set by parallel studies. The participants were given forty-five minutes to answer the questionnaire; the questionnaires were then analyzed by grading the respondents into three categories: poor, unsatisfactory and satisfactory.Results: This study showed satisfactory results about awareness, knowledge and methods of application of pharmacovigilance among final year medical students 55%, 47%, 54% respectively and positive correlation between awareness, knowledge and methods of application of pharmacovigilance among final year medical students significantly (<0.0001) correlated.Conclusions: The present study revealed that the final year medical students were satisfactory in awareness and knowledge and methods of application of pharmacovigilance. The correlations told that the higher the awareness, the more was the knowledge and better were the methods of application. Likewise, the knowledge and practices were significantly and positively related to a correlation