1,240 research outputs found

    Ring seine fishery of Kerala: An overview

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    Among the various fishing gears employed for pelagic schooling fishes along the Kerala coast, seines are the most efficient. Contribution of ring seine to total marine fish landings of Kerala has steadily increased since its introduction during the early eighties. It was 21.4 % in the nineties rising to 36.7 % during the period 2000-2004 and contributing more than 50 % since then. In recent years, about 90 % of the oil sardine and about 60 % of the mackerel landed in Kerala were caught in ring seines. Ring seines were introduced during the early eighties by traditional fishers of Alappuzha District which became highly successful

    Recovering the Inflationary Potential

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    A procedure is developed for the recovery of the inflationary potential over the interval that affects astrophysical scales (\approx 1\Mpc - 10^4\Mpc). The amplitudes of the scalar and tensor metric perturbations and their power-spectrum indices, which can in principle be inferred from large-angle CBR anisotropy experiments and other cosmological data, determine the value of the inflationary potential and its first two derivatives. From these, the inflationary potential can be reconstructed in a Taylor series and the consistency of the inflationary hypothesis tested. A number of examples are presented, and the effect of observational uncertainties is discussed.Comment: 13 pages LaTeX, 6 Figs. available on request, FNAL-Pub-93/182-

    Non--Gaussian Effects in the Cosmic Microwave Background from Inflation

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    The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation. These features could shed some light on the non trivial task of distinguishing the real source of the primeval perturbations leading to large scale structure. One of the simplest non--Gaussian signals to search is the (dimensionless) skewness S{\cal S}. Explicit computations for S{\cal S} are presented in the frame of physically motivated inflationary models (natural, intermediate and polynomial potential inflation) in the hope of finding values in agreement with estimated quantities from large angle scale (e.g., {\em COBE} DMR) maps. In all the cases considered the non--Gaussian effects turn out to lie below the level of theoretical uncertainty (cosmic variance). The possibility of unveiling the signal for S{\cal S} with multiple--field models is also discussed.Comment: To appear in Physical Review D ; 17pp LaTeX; now including 5 figures in one PostScript file appended at the end ; SISSA REF.73/94/

    Anisotropy in the Cosmic Microwave Background at Degree Angular Scales: Python V Results

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    Observations of the microwave sky using the Python telescope in its fifth season of operation at the Amundsen-Scott South Pole Station in Antarctica are presented. The system consists of a 0.75 m off-axis telescope instrumented with a HEMT amplifier-based radiometer having continuum sensitivity from 37-45 GHz in two frequency bands. With a 0.91 deg x 1.02 deg beam the instrument fully sampled 598 deg^2 of sky, including fields measured during the previous four seasons of Python observations. Interpreting the observed fluctuations as anisotropy in the cosmic microwave background, we place constraints on the angular power spectrum of fluctuations in eight multipole bands up to l ~ 260. The observed spectrum is consistent with both the COBE experiment and previous Python results. There is no significant contamination from known foregrounds. The results show a discernible rise in the angular power spectrum from large (l ~ 40) to small (l ~ 200) angular scales. The shape of the observed power spectrum is not a simple linear rise but has a sharply increasing slope starting at l ~ 150.Comment: 5 page

    Abnormalities in Indian oil sardine

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    Routine sampling of Indian oil Sardine, Sardinella longiceps, for biological studies was done . On 31st December, 2017, out of 61 specimens collected, one sardine with blunted snout (Fig. 1) and one with deformed caudal fin (Fig. 2) was observed

    A Plasmodium membrane receptor platform integrates cues for egress and invasion in blood forms and activation of transmission stages

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    Critical events in the life cycle of malaria-causing parasites depend on cyclic guanosine monophosphate homeostasis by guanylyl cyclases (GCs) and phosphodiesterases, including merozoite egress or invasion of erythrocytes and gametocyte activation. These processes rely on a single GCalpha, but in the absence of known signaling receptors, how this pathway integrates distinct triggers is unknown. We show that temperature-dependent epistatic interactions between phosphodiesterases counterbalance GCalpha basal activity preventing gametocyte activation before mosquito blood feed. GCalpha interacts with two multipass membrane cofactors in schizonts and gametocytes: UGO (unique GC organizer) and SLF (signaling linking factor). While SLF regulates GCalpha basal activity, UGO is essential for GCalpha up-regulation in response to natural signals inducing merozoite egress and gametocyte activation. This work identifies a GC membrane receptor platform that senses signals triggering processes specific to an intracellular parasitic lifestyle, including host cell egress and invasion to ensure intraerythrocytic amplification and transmission to mosquitoes

    Measurements of Sunyaev-Zel'dovich Effect Scaling Relations for Clusters of Galaxies

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    We present new measurements of the Sunyaev-Zel'dovich (SZ) effect from clusters of galaxies using the Sunyaev-Zel'dovich Infrared Experiment (SuZIE II). We combine these new measurements with previous cluster observations with the SuZIE instrument to form a sample of 15 clusters of galaxies. For this sample we calculate the central Comptonization, y, and the integrated SZ flux decrement, S, for each of our clusters. We find that the integrated SZ flux is a more robust observable derived from our measurements than the central Comptonization due to inadequacies in the spatial modelling of the intra-cluster gas with a standard Beta model. This is highlighted by comparing our central Comptonization results with values calculated from measurements using the BIMA and OVRO interferometers. On average, the SuZIE calculated central Comptonizations are approximately 60% higher in the cooling flow clusters than the interferometric values, compared to only approximately 12% higher in the non-cooling flow clusters. We believe this discrepancy to be in large part due to the spatial modelling of the intra-cluster gas. From our cluster sample we construct y-T and S-T scaling relations. The y-T scaling relation is inconsistent with what we would expect for self-similar clusters; however this result is questionable because of the large systematic uncertainty in the central Comptonization. The S-T scaling relation has a slope and redshift evolution consistent with what we expect for self-similar clusters with a characteristic density that scales with the mean density of the universe. We rule out zero redshift evolution of the S-T relation at 90% confidence.Comment: Accepted to Astrophysical Journal. 52 pages, 14 tables, 7 figures ;replaced to match ApJ accepted versio

    Comparing Cosmic Microwave Background Datasets

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    To extract reliable cosmic parameters from cosmic microwave background datasets, it is essential to show that the data are not contaminated by residual non-cosmological signals. We describe general statistical approaches to this problem, with an emphasis on the case in which there are two datasets that can be checked for consistency. A first visual step is the Wiener filter mapping from one set of data onto the pixel basis of another. For more quantitative analyses we develop and apply both Bayesian and frequentist techniques. We define the ``contamination parameter'' and advocate the calculation of its probability distribution as a means of examining the consistency of two datasets. The closely related ``probability enhancement factor'' is shown to be a useful statistic for comparison; it is significantly better than a number of chi-squared quantities we consider. Our methods can be used: internally (between different subsets of a dataset) or externally (between different experiments); for observing regions that completely overlap, partially overlap or overlap not at all; and for observing strategies that differ greatly. We apply the methods to check the consistency (internal and external) of the MSAM92, MSAM94 and Saskatoon Ring datasets. From comparing the two MSAM datasets, we find that the most probable level of contamination is 12%, with no contamination only 1.05 times less probable, and 100% contamination strongly ruled out at over 2 X 10^5 times less probable. From comparing the 1992 MSAM flight with the Saskatoon data we find the most probable level of contamination to be 50%, with no contamination only 1.6 times less probable and 100% contamination 13 times less probable. [Truncated]Comment: LaTeX, 16 pages which include 16 figures, submitted to Phys. Rev.

    Foregrounds in the BOOMERANG-LDB data: a preliminary rms analysis

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    We present a preliminary analysis of the BOOMERanG LDB maps, focused on foregrounds. BOOMERanG detects dust emission at moderately low galactic latitudes (b>20ob > -20^o) in bands centered at 90, 150, 240, 410 GHz. At higher Galactic latitudes, we use the BOOMERanG data to set conservative upper limits on the level of contamination at 90 and 150 GHz. We find that the mean square signal correlated with the IRAS/DIRBE dust template is less than 3% of the mean square signal due to CMB anisotropy

    Effective Utilization of Local Genetic Diversity of Pigeonpea, Sorghum and Finger Millet in Eastern and Southern Africa: Impacts and Prospects

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    Eastern and Southern Africa (ESA) is the centre of genetic diversity for pigeonpea, sorghum and Finger millet. ICRISAT regional bank located in Nairobi-Kenya maintains about 6000 germplasm accessions that are of greater use in ESA. ICRISAT-Nairobi is regularly collecting local diversity existing in the region and thus collected germplasm characterized/evaluated to identify locally adapted germpalsm with highly desirable traits. Local diversity captured in ESA has unique traits with respect to local agro-ecological adaptation, farmer and consumer preferred grain traits, tolerance to drought and region specific diseases. ESA regional germplasm also contributed to global genetic diversity maintained ICRISAT-Patancheru in several ways. During recent years 30 new varieties of pigeonpea (8), sorghum (10) and Finger millet (12) were released in eight ESA countries and occupying huge area in respective countries. Pigeonpea is an example crop with great success recorded during last 15 years when breeding program started using local germplasm. Pigeonpea improvement in ESA started in 1992 by mostly relying on native germplasm and through this 33 high yielding varieties that are belonging to short(8), medium(13) and long(12) maturity group were released. A strong region specific genetic enhancement program is in operation with major breeding thrust on high grain yield, inter-cropping compatibility, photoperiod insensitivity, grain quality, resistance and/or tolerance to Fusarium wilt and Helicoverpa pod borer and resilience to climate change. Most of the cultivated germplasm is susceptible to insects but regional germplasm contributed develop that are insect-cum-drought tolerant, high yielding and big seeded (28 g/100 seed mass). ESA region has huge untapped potential with respect to genetic diversity and its use in genetic enhancement
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