Epidemiological approaches for aquatic disease control - Winter school on recent advances in diagnosis and management of diseases in mariculture, 7th to 27th November 2002, Course Manual

The importance of aquaculture to food security is well known, Aquaculture development therefore, has assumed significant momentum in several parts of the world. Diseases are among the greatest deterrents to the sustained production in aquaculture. Diseases like Epizootic Ulcerative Syndrome (ELiS) in fishes and White Spot Syndrome (WSS) in shrimps have amply demonstrated the devastating effect of disease outbreaks on aquaculture productivity and profitability Various diagnostic and health management tools are being.used to devise disease control strategies. It is becoming increasingly difficult to manage pathogens that have become endemic. Epidemiological approaches which have been very successful in human and veterinary medicine are now being increasingly recognised as important weapons that can be used in aquaculture to formulate disease control programmes

SDSS J092712.64+294344.0: recoiling black hole or merging galaxies?

We report long-slit spectroscopic observations of SDSS J092712+294344 carried-out at the recently commissioned 2m telescope in IUCAA Girawali Observatory, India. This AGN-like source is known to feature three sets of emission lines at zem = 0.6972, 0.7020 and 0.7128. Different scenarios such as a recoiling black hole after asymmetric emission of gravitational waves, binary black holes and possible merging systems are proposed for this object. We test these scenarios by comparing our spectra with that from the Sloan Digital Sky Survey (SDSS), obtained 4 years prior to our observations. Comparing the redshifts of [OIII]4960,5008 we put a 3 sigma limit on the relative acceleration to be less than 32 km s^-1 yr^-1 between different emitting regions. Using the 2D spectra obtained at different position angles we show that the [OIII]5008 line from the zem = 0.7128 component is extended beyond the spectral point spread function. We infer the linear extent of this line emitting region is ~8 kpc. We also find a tentative evidence for an offset between the centroid of the [OIII]5008 line at zem = 0.7128 and the QSO trace when the slit is aligned at a position angle of 299 degrees. This corresponds to the zem = 0.7128 system being at an impact parameter of ~1 kpc with respect to the zem = 0.6972 in the north west direction. Based on our observations we conclude that the binary black hole model is most unlikely. The spatial extent and the sizes are consistent with both black hole recoil and merging scenarios.Comment: accepted for publication in MNRAS Letter

Pathological processes and disease development - Winter school on recent advances in diagnosis and management of diseases in mariculture, 7th to 27th November 2002, Course Manual

Diseases are among the greatest deterrents to the sustained production in aquaculture. White spot diseases (WSD) in cultured shrimp and epizootic ulcerative syndrome (EUS) in fishes have amply demonstrated the serious impact of disease in aquaculture. Aquaculture medicine, which broadly encompasses prevention and management of diseases in cultured aquatic organisms, becomes a vital requirement for a sustained industry

Modulatory effects of cadmium and copper on the susceptibility and immune response of common carp, Cyprinus carpio (L) to selected pathogens

Pollution of the aquatic environment has received considerable attention in recent years. The fear that pollutants might predispose fish to disease is a cause of great concern. Recent evidence has shown that, in the case of some pollutants, the fear was well-founded. The lack of detailed studies in this field prompted the present study. A comprehensive approach was made towards understanding the effects of two common aquatic pollutants, the metals cadmium and copper, at sublethal levels, on the disease resistance and immune response mechanisms of common carp, Cyprinus carpio L. Two pathogens were used as models, which differ from each other with respect to the nature of the disease processes and their cellular requirements for optimal immune response. Ichthyophthirius multifiliis (Fouquet), the causative agent of white spot disease and Aeromonas hydrophila which causes bacterial haemorrhagic septicaemia were employed to examine the immunomodulatory effects of the metals. A third model, Sheep Red Blood Cell, with known cellular requirements and immunokinetics, was used as a reference antigen. The in vitro and in vivo effects of the metals on lymphocyte proliferation induced by putative T and B-cell mitogens were also evaluated. The ability of the metals to induce a stress response in carp was assessed by monitoring the kinetics of plasma cortisol. Subtle structural changes produced by the metals in the primary barriers and haematopoietic organs were also examined histologically. Exposure of naïve carp for 10 days to sublethal levels (50****) of cadmium and copper significantly increased their susceptibility to I. multifiliis as measured by mean parasite intensity. Previously immunized carp with established immunity and high “tomite agglutination titre” could not mount a protective immune response following 10 days exposure to 25 and 50 **** cadmium and copper. Concurrent exposure of carp to either cadmium or copper with a series of controlled low level immunization exposures to the parasite, did not alter the kinetics nor the magnitude of the “anti-ich” humoral antibody titre. Control carp acquired complete resistance earlier than metal exposed ones. Exposure of carp to cadmium (50 *** *) or copper (30 ****) for 40 days with the primary immunization given 10 days after the commencement of metal exposure did not reduce the primary antibody response, but significantly reduced the magnitude of the secondary response. Similar experimental conditions also revealed die significant suppressive effects of these metals on the number of both Rosette Forming and Plaque Forming Cells. Long term exposure (30 days) to cadmium before the primary immunization did not impair the kinetics and magnitude of the primary and secondary humoral response, but, in contrast, copper significantly suppressed both the primary and secondary response. Exposure of carp to the metals 18 days after the primary immunization with SRBC significantly reduced the magnitude of the secondary humoral response. Primary immunization given concurrently with the commencement of metal exposure, significantly reduced the magnitude of both the primary and secondary response. Carp exposed to cadmium and copper for 10 days were more susceptible to A. hydrophila than unexposed controls. Previously immunized carp could not mount an effective protective immunity following 10 days exposure. In contrast to I. multifiliis, the decrease in the protective immunity was associated with a significant drop in the humoral bacterial agglutination titre. Exposure to the metals for 10 days before immunization with A. hydrophila heat killed bacterin reduced the magnitude of the humoral reprise significantly. Immunization carried out simultaneously with the commencement of metal exposure suppressed the magnitude of both the primary and secondary humoral antibody response. Lymphocytes collected from carp exposed to cadmium (50 Ugl ') or copper (30 ****) showed a reduced blastogenic response to the mitogens concanavalin (Con A) and lipopolysaccharide (LPS). A significant suppression was observed in lymphocytes collected after 6 to 9 days of exposure to the respective metals. Both the metals in vitro showed similar suppressive effects. Concentrations of 10**M (copper) or 10**M (cadimum) and greater, suppressed the mitogenic response to both the mitogens significantly. Exposure to both the metals induced a stress response, characterized by elevation of plasma cortisol. The elevation in cadmium expired carp was transitory in nature, the values returning to near basal values and persisting at that level till the end of the experimental duration. In the copper exposed carp, the cortisol decreased gradually from the maximum seen following 24 hours until day 9 before showing a secondary elevation which persisted. Both the metals produced leucopenia. Cadmium exposure did not have any effect on the haematocrit, whilst copper caused an elevation. The pathological effects on the structure of the primary barriers were considerable at the concentrations tested. The pathological changes in the haematopoietic organs were not so severe, but included multifocal necrosis of the haematopoietic tissue and indications of fragmentation of malanomacrophage centres in the kidney and spleen. Both cadmium (50 ****) and copper (30 ****) did not completely abrogate the immune response of carp. Studies evaluating the immunotoxicity of aquatic pollutants should give more emphasis to the magnitude of suppression rather than looking for a complete abrogation of immune response. This study has clearly shown that a reduction in the magnitude of the immune response is sufficient to predispose fish to disease. These findings are significant when assessing the impact of these pollutants and when determining the maximum limits tolerable in the natural environment

New surveys of UBV photometry and absolute proper motions at intermediate latitude

A photometric and proper motion survey has been obtained in 2 directions at intermediate latitude: ($l=167.5^\circ$, $b=47.4^\circ$; $\alpha_{2000}=9^h41^m26^s$,$\delta_{2000}=+49^\circ53'27''$) and ($l=278^\circ$, $b=47^\circ$; $\alpha_{2000}=11^h42^m56^s$, $\delta_{2000}=-12^\circ31'42''$). The survey covers 7.13 and 20.84 square degrees, respectively. The limiting magnitude is about 18.5 in V for both directions. We have derived the density laws for stars (M$_{V}$ $\ge$ 3.5) as a function of distance from the galactic plane. The density laws for stars follow a sum of two exponentials with scale heights of 240 pc (thin disk) and 790 pc (thick disk), respectively. The local density of thick disk is found to be 6.1$\pm$3 % relative to the thin disk. The kinematical distribution of stars has been probed to distances up to 3.5 kpc above the galactic plane. New estimates of the parameters of velocity ellipsoid have been derived for the thick disk of the Galaxy. A comparison of our data sets with the Besan\c con model star count predictions has been performed, giving a good agreement in the magnitude range V = 13 to 18.Comment: 13 pages, 8 PS figures, To appear in A&

Stroboscopic Generation of Topological Protection

Trapped neutral atoms offer a powerful route to robust simulation of complex quantum systems. We present here a stroboscopic scheme for realization of a Hamiltonian with $n$-body interactions on a set of neutral atoms trapped in an addressable optical lattice, using only 1- and 2-body physical operations together with a dissipative mechanism that allows thermalization to finite temperature or cooling to the ground state. We demonstrate this scheme with application to the toric code Hamiltonian, ground states of which can be used to robustly store quantum information when coupled to a low temperature reservoir.Comment: 5 pages, 2 figures. Published versio

Probing the time variability of five Fe low broad absorption line quasars

We study the time variability of five Fe Low ionization Broad Absorption Line (FeLoBAL) QSOs using repeated spectroscopic observations with the 2m telescope at IUCAA Girawali observatory (IGO) spanning an interval of upto 10 years. We report a dramatic variation in Al III and Fe III fine-structure lines in the spectra of SDSS J221511.93-004549.9 (z_em ~ 1.478). However, there is no such strong variability shown by the C IV absorption. This source is known to be unusual with (i) the continuum emission dominated by Fe emission lines, (ii) Fe III absorption being stronger than Fe II and (iii) the apparent ratio of Fe III UV 48 to Fe III UV 34 absorption suggesting an inverted population ratio. This is the first reported detection of time variability in the Fe III fine-structure lines in QSO spectra. There is a strong reduction in the absorption strength of these lines between year 2000 and 2008. Using the template fitting techniques, we show that the apparent inversion of strength of UV lines could be related to the complex spectral energy distribution of this QSO. The observed variability can be related to change in the ionization state of the gas or due to transverse motion of this absorbing gas. The shortest variability timescale of Al III line gives a lower limit on the electron density of the absorbing gas as n_e >= 1.1 x 10^4 cm^-3. The remaining 4 FeLoBALs do not show any changes beyond the measurement uncertainties either in optical depth or in the velocity structure. We present the long-term photometric light curve for all of our sources. Among them only SDSS J221511.93-004549.9 shows significant (>= 0.2 mag) variability.Comment: 15 pages, 9 figures, 3 tables, Accepted for publication in MNRA

Role of Epidermal growth factor receptor in odontogenic epithelium and development of odontogenic lesions

Growth is a highly coordinated process which is sustained by several growth factors and apoptotic factors. Any disturbance in this delicate balance leads to pathologies and genes that have such potential to produce tumors when mutated are known as oncogenes. EGFR an important growth factor that is involved in several physiological processes is presently one of the most common genes in targeted cancer therapies. Though, its potential as an oncogene target in head and neck epithelial tumors like squamous cell carcinoma is gaining importance and opening doors to revolutionizing cancer treatment modalities, its role in other head and neck epithelia like odontogenic epithelia remains vague and needs attention. The present article highlights some of the key findings in our research evaluating the role of EGFR in physiologic odontogenic epithelium that is comprised within pericoronal follicles. The research involved study of immunohistochemical examination of 35 pericoronal follicles removed from patients with asymptomatic impacted tooth extractions. The follicles were assessed for intensity, percentage of staining and location of the EGFR stain. The follicles predominantly showed intense staining pattern and location of EGFR positivity in most epithelium and rests were combined both cytoplasmic and membrane positivity. These findings reemphasize the inherent proliferative potential present in follicles and their role in formation of odontogenic tumors like ameloblastomas in long term impacted teeth. The potential of EGFR as a treatment target in odontogenic tumors also remains plausible

Adaptive homodyne phase discrimination and qubit measurement

Fast and accurate measurement is a highly desirable, if not vital, feature of quantum computing architectures. In this work we investigate the usefulness of adaptive measurements in improving the speed and accuracy of qubit measurement. We examine a particular class of quantum computing architectures, ones based on qubits coupled to well controlled harmonic oscillator modes (reminiscent of cavity-QED), where adaptive schemes for measurement are particularly appropriate. In such architectures, qubit measurement is equivalent to phase discrimination for a mode of the electromagnetic field, and we examine adaptive techniques for doing this. In the final section we present a concrete example of applying adaptive measurement to the particularly well-developed circuit-QED architecture.Comment: 9 pages, 8 figures. Published versio

Removal of chlorobenzene and 1,4-dichlorobenzene using novel poly-o-toluidine zirconium(IV) phosphotellurite exchanger

Novel hybrid exchanger poly-o-toluidine zirconium(IV) phosphotellurite was synthesized and physicochemical properties of the material were well studied by FTIR, XRD, TGA, SEM-EDX and TEM analysis. The composite exchanger showed good ion exchange capacity and excellent removal potential towards US Environmental Protection Agency listed priority pollutants like chlorobenzene and 1,4-dichlorobenzene. The factors affecting the adsorption like time, pH and temperature were studied in detail using UV spectrophotometry. More than 90% of the pollutants were successfully removed using the exchanger. The composite also showed selectivity towards heavy metal ions, especially mercury ions. The sorption kinetics of the material was studied in detail using pseudo first order and pseudo second order kinetics. The material followed pseudo second order kinetic model indicating chemisorption of the pollutants. The composite can be successfully used for environmental remediation purposes