1,244 research outputs found
Studies on the food and feeding relationships of the halfbeak fishes (Hemirhamphidae) from the Gulf of Mannar and Palk Bay
As a part of the investigations of the biology of the hemirhamphids in the
Gulf of Mannar and Palk Bay from 1957-59, the contents of 2221 guts
belonging to four species, viz., Hyporhamphus georgii (C.V.), H. quoyi (C.V.),
Hemirhamphus marginatus (Forsk.) and H. far (Forsk.) were examined. No
detailed information on the food and feeding habits of the half beaks is available
and the accounts given by Schlesinger (1909), Uchida (1930), Smith
(1933), Devanesan (1933), Graham (1938), Suyehiro (1942), Gnanamuthu
(1943), Chacko (1949), Tham Ah Kow (1950), Thompson (1957 and 1959),
Vijayaraghavan (1957) and Kuthalingam (1958) relate mainly to observations
confined to limited periods in a year and do not give a picture of the
variations of the seasonal composition of the gut contents. The present study
deals with the seasonal composition of the food items of four species of halfbeaks
and its relation to the environmental biota and their stages of sexual
maturity
Mary Coble: Performance Art and Poltics of an Archive
This dissertation explores the relationships among performance art, the archive and intersubjectivity. Using methods of critical ethnography, visual and textual analysis, I examine the archive of performance art, and the discourses of the body, especially in the work of performance artist Mary Coble. I explore the ways in which performance art disrupts the ideological discourses of the institutional archive, especially those surrounding the body and constructing normative sexual and civic identities. The institutional archive has served as a guardian of memory that makes it the creator of knowledge. Performance artists work within the conceptual space of an archive as a way to make visible the ideological systems of power; this they do through reenactments and re-presentations, in effect creating a counter-archive of political and gendered memorial spaces. I question how performance artists, critiquing the visual hegemony of the white, male dominated art world, confront issues of identity and difference, including ones of race, gender, sexuality and citizenship. I am interested in how "knowledge" is situated in the embodied experiences of the performer, researcher, artist, community and its participants. In this sense the archive is not simply a site of documentation and knowledge retrieval, but also as a locus of the feelings and emotions that produce knowledge and meaning
Fibre Optics in Undersea Applications
Role of optical fibres for underwater communication cables and hydrophones is discussed. The fibre optics cables provide an excellent solution to the historical bandwidth-diameter problems of conventional coaxial cables.Fibre optic hydrophones are found to have many more advantages apart from high sensitivity and large dynamic range, over the classical sound sensors used in underwater work
Sinkholes in Earth Dam Kota Barrage [India]
Kota Barrage is the lowermost hydraulic structure amongst the series of four dams built across the river Chambal, a tributary of the river Yamuna in the Ganga Basin. It is situated near the Kota City, Rajasthan in India and is in operation since November, 1960 with an irrigation potential of 679 thousand ha in two adjoining states of Rajasthan and Madhya Pradesh. It comprises of a composite structure consisting of a 268.2m long earth and rockfill dam and a 304.8m long masonry spillway, the total length being 573.0m The earth/rockfill dam abuts in the right against a hillock over which a very old Garh Complex exists and two fort walls intervened in between the spillway and the abutment have divided the dam into three distinct reaches having different foundation sub-strata. The spillway rests on hard quartzitic sand stone with high rock face in the left flank and is provided with 19-radial gates (12 2m x 12.2m each) and 2-under-sluices (2. 7m x 3.3m) to discharge 21240 cumecs at MWL 260.9m. Heavy leakage of water through the bed rock crevices in the adjacent right abutment resting on hillock stope wet spots on downstream edge alongwith repeated settlements and formation of sinkholes on top of the dam has led to a great concern about safety of the dam. Geo-technical investigations carried out recently revealed some lenses/zones with low density soilmass and higher permeability at places in the embankment
A contribution to the biology of the halfbeak, Hyporhamphus georgii (Cuv. & Val.) (Hemirhamphidae)
The hemirhamphids constitute an important group of the neretic-pelagic
fisheries of the Gulf of Mannar and Palk Bay. Although there are eight
species of halfbeaks distributed in these waters, Hyporhamphus georgii (C.V.)
and Hemirhamphus marginatus (Forsk.) are the only species which may be
considered of sufficient importance to constitute a distinct ' fishery'. With
a view to obtaining accurate information on the fishery biology of these common
species, a detailed investigation was taken up during 1957-59
Studies on the biology of Hemirhamphus marginatus (Forskal) (Hemirhamphidae—Pisces)
Investigations on the biology of the common species of hemirhamphids in the
Gulf of Mannar and Palk Bay was initiated in 1957. The biology of Hyporhamphus
georgii (C.V.) has already been dealt with (Talwar, 1962b) and an account of the
food and feeding habits of Hemirhamphus marginatus (Forskal) has been discussed
in a separate contribution (Talwar, 1962a). Observations on the biology of H.
marginatus in the Mandapam area during the period January 1957 to Jahuary 1959
and the results obtained are presented in the following account.
The species contributes to a seasonal fishery in the Gulf of Mannar for about
three months viz., November to January. The Appathivu and Baliyanathivu
C thivu' in Tamil means an island)—Lat. 9°5' N. Long. 78°, 45'-50' E.) arethe taain
fish-landing centres. The shore seine accounts for most of the catches
Properties and characteristics of an anti-human chorionic gonadotropin monoclonal antibody
The product of a hybrid cell clone, P3W80, obtained as ascites fluid from mouse peritoneal cavity had high titres of anti-human chorionic gonadotropin antibodies e.g. 30 to 40% binding of 125I-human chorionic gonadotropin at 107 dilution in a radioimmunoassay. The antiserum SB6 (raised against β-human chorionic gonadotropin distributed by National Institutes of Health, USA gave similar binding at 5000 dilution in parallel runs. The monoclonal antibody recognized best human chorionic gonadotropin (0.3 mlU of hormone/tube with B/B0 < 75%), but also bound β and α subunits of human chorionic gonadotropin, 12 and 800 folds lower than human chorionic gonadotropin respectively No binding was observed with carboxy terminal peptides of β-human chorionic gonadotropin ranging from 93 to 145 amino acid residues, indicating the lack of recognition of the C-terminal region. No cross-reaction with human leutinizing hormone was obtained at the physiological surge levels, a significant competition (B/B0 < 75 %. obtainable only at 60 mlU of LER 960 human leutinizing hormone/ tube. The antibody had heavy chain of IgG1 and light chain of kappa type. It neutralized the bio-activity of human chorionic gonadotropin bothin vitro and invivo
Delineation of downstream signalling components during acrosome reaction mediated by heat solubilized human zona pellucida
<p>Abstract</p> <p>Background</p> <p>Human egg is enveloped by a glycoproteinaceous matrix, zona pellucida (ZP), responsible for binding of the human spermatozoa to the egg and induction of acrosomal exocytosis in the spermatozoon bound to ZP. In the present manuscript, attempts have been made to delineate the downstream signalling components employed by human ZP to induce acrosome reaction.</p> <p>Methods</p> <p>Heat-solubilized human ZP (SIZP) was used to study the induction of acrosome reaction in capacitated human spermatozoa using tetramethylrhodamine isothiocyanate conjugated <it>Pisum sativum </it>agglutinin (TRITC-PSA) in absence or presence of various pharmacological inhibitors. In addition, intracellular calcium ([Ca2+]i) levels in sperm using Fluo-3 acetoxymethyl ester as fluorescent probe were also estimated in response to SIZP.</p> <p>Results</p> <p>SIZP induces acrosomal exocytosis in capacitated human sperm in a dose dependent manner accompanied by an increase in [Ca2+]i. Human SIZP mediated induction of acrosome reaction depends on extracellular Ca2+ and involves activation of Gi protein-coupled receptor, tyrosine kinase, protein kinases A & C and phosphoinositide 3 (PI3)- kinase. In addition, T-type voltage operated calcium channels and GABA-A receptor associated chloride (Cl-) channels play an important role in SIZP mediated induction of acrosome reaction.</p> <p>Conclusions</p> <p>Results described in the present study provide a comprehensive account of the various downstream signalling components associated with human ZP mediated acrosome reaction.</p
Isolation and characterization of cDNA clones for α- and β-subunits of ovine luteinizing hormone
A cDNA library of ovine pituitary DNA in plasmid pBR322 has been constructed by conventional methods with certain modifications. The library was screened using partial cDNAs for rat α-subunit and LHβ. We have isolated cDNA clones for ovineα -subunit and LHβ. The identification of these clones was confirmed by partial sequencing. The clones bear about 80% sequence homology with the respective rat cDNAs in the sequenced regions and hybridize with the rat clones in 5 X SSC at 55°C. The ovine LHβ clone has an insert of about 650 bp and selects an RNA of about 750 bases in a northern blot. The α-subunit cDNA clone has an insert of about 550 bp; it has two internal Pst I sites and thus shows restriction-based differences from rat α-subunit cDNA, which does not have anyPst I site
Truthful Multi-unit Procurements with Budgets
We study procurement games where each seller supplies multiple units of his
item, with a cost per unit known only to him. The buyer can purchase any number
of units from each seller, values different combinations of the items
differently, and has a budget for his total payment.
For a special class of procurement games, the {\em bounded knapsack} problem,
we show that no universally truthful budget-feasible mechanism can approximate
the optimal value of the buyer within , where is the total number of
units of all items available. We then construct a polynomial-time mechanism
that gives a -approximation for procurement games with {\em concave
additive valuations}, which include bounded knapsack as a special case. Our
mechanism is thus optimal up to a constant factor. Moreover, for the bounded
knapsack problem, given the well-known FPTAS, our results imply there is a
provable gap between the optimization domain and the mechanism design domain.
Finally, for procurement games with {\em sub-additive valuations}, we
construct a universally truthful budget-feasible mechanism that gives an
-approximation in polynomial time with a
demand oracle.Comment: To appear at WINE 201
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