583 research outputs found
Trends and Establishment of Shell Effects in (n, d), (n, t) and (n, 3He) Reaction Cross Sections Around 14 MeV
Seismic vulnerability assessment: Methodological elements and applications to the case of Romania
This paper is intended to present some studies undertaken in order to develop a seismic vulnerability estimation system to fit the needs of development of earthquake scenarios and of development of an integrated disaster risk management system for Romania. Methodological aspects are dealt with, in connection with the criteria of categorization of buildings, with the definition of parameters used for characterizing vulnerability, with the setting up of an inventory of buildings and with the calibration of parameters characterizing vulnerability. Action was initiated along the coordinates referred to in connection with the methodological aspects mentioned above. The approach was made, as far as possible, specific to the conditions of Romania. Some data on results obtained to date are presented.seismic vulnerability, vulnerability estimation, earthquake scenarios, categorization of buildings, inventory of buildings, expected earthquake impact
Identification of female specific protein in seabass, Lates calcarifer (Bloch)
Electrophoretic serum protein profile of female Lates calcarifer reveals appearance
of female specific protein during gonadotropic dependent stages of ovarian growth.
The protein is conspicuously absent in the serum of maturing males. The protein
stains positively for carbohydrate, lipids and calcium indicating it to be vitellogenin.
The vitellogenin band first appears in fish with maturing ovaries (stage 3) and
stain intense and sharp till stage 4. At stage 5 (ripe) the band appears diffused.
The protein is lacking in the serum profile of immature (stage 1), resting preparatory
(stage 2) and spent (stage 6) as well as in maturing male fish. The
correlative pattern of vitellogenin band with ovarian maturation stages provides
evidence of single spawning in L. calcarifer
Effect of extender composition on sperm cryopreservation of Asian catfish Heteropneustes fossilis (Bloch) and Clarias batrachus (Linnaeus)
Air breathing catfish species Heteropneustes fossilis (Bloch) and Clarias batrachus
(Linn.) are important table fish and fetch high market price. Cryopreservation of spermatozoa
can be a useful tool in captive seed production for domestication and aquaculture of these catfish
species. The objective of the present study was to identify optimum extender composition for
sperm cryopreservation of the two species, H. fossilis and C. batrachus. Four extender
compositions Hank’s Balanced Salt Solution (HBSS), Modified Hank’s Balanced Salt Solution
(M-HBSS), Modified Hank’s Balanced Salt Solution with hen’s egg yolk (M-HBSS with EY)
and European catfish were evaluated for cryopreservation of catfish sperm and 10 % Dimethyle
Sulphoxide (DMSO) was used as a cryoprotectant. The pooled milt exhibiting 70-80% motile
sperm was used for cryopreservation experiment. After storage for 48 hrs at -196ºC, the milt was
thawed and evaluated for fertility test. The percentage of hatching was used as a parameter for
the comparative evaluation of different extender composition. In H. fossilis extender M-HBSS
indicated highest hatching rate (49.06%), followed by HBSS (42.76%), M-HBSS with EY
(37.46%) and European catfish (29.47%). The hatching success with extender M-HBSS did not
differ significantly (P > 0.05) from the control group (51%). In C. batrachus extender HBSS
exhibited highest hatching (62.1 %), followed by M-HBSS with EY (51.6%), European Catfish
(46.3%) and M-HBSS (40.9%). The hatching rate in control was 90% in C. batrachus. The
results indicated that the two species differ in the protocol for sperm cryopreservation. The
paper presents successful cryopreservation of sperm with the production of viable hatchlings of
H. fossilis and C. batrachus for the first time. The protocol reported in the study can be used for
scaling up of seed production of these two catfish species
A molecular approach to reveal the genetic identity of parrot mussel and other sympatric mussel species distributed along the Kerala coast
Two commercially important mussel species are recorded from the Indian coast: green mussel Perna
viridis (Linnaeus, 1758) and brown mussel P. indica (Kuriakose and Nair, 1976). Apart from this, a
third type referred to as parrot mussel, which has shell shape of brown mussel, but with green shell
colouration and suspected to be the hybrid of the above two species has also been reported from Kollam
coast of Kerala, where both the species co-occur. In the present work, genetic identity of parrot and
sympatric mussel species was determined using protein and genomic DNA markers. Protein markers
viz. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) and allozymes and
the genomic DNA marker Random Amplified Polymorphic DNA (RAPD) were used for determining
genetic identity of the three mussel groups. The green and brown mussels could be clearly differentiated
using SDS PAGE. The parrot mussel protein pattern was similar to that of brown mussel, except for
an additional band of molecular weight 48.7 Kda which is unique to brown mussel. Genus specific
protein bands for Perna viz. 66 Kda, 43 Kda and 14.3 Kda, were detected in this study. Allozyme
electrophoresis also followed a similar pattern. Of the 10 allozyme loci studied, seven revealed speciesspecific
diagnostic differences between P.viridis and P.indica. They were AAT-1* (Aspartate Amino
Transferase-1*), AAT-2*, ME (Malic Enzyme)*, PGM-2*(Phospo Gluco Mutase-2*), EST-1* (Esterase-
1*), EST-2*, IcDH* (Isocitrate Dehydrogenase)*. Parrot mussel shared all the alleles of brown mussel,
and no hybrid pattern was observed. Species-specific alleles clearly differentiated green mussel from
both brown and parrot mussel. The genetic distance of green mussel from brown mussel, estimated
from allozyme data was 1.1145 and with parrot mussel it was 1.105. The genetic distance between
parrot mussel and brown mussel was negligibly low (0.0005). Using allozyme and RAPD data, the
Nei’s Unbiased Measures of genetic distance were calculated and the dendograms prepared based on
these values clearly depicted the separation of parrot mussel from green mussel as well as the close
resemblance of parrot mussel with brown mussel. The higher gene flow (1.1539) determined using
RAPD marker also hints that brown and parrot mussel may be acting as single interbreeding population.
Hence this study using molecular tools to test the genetic identity of parrot mussel has helped to
conclude that parrot mussel is only a morphotype of brown mussel and not a true hybrid of the two
Low Genetic Differentiation in the Populations of the Malabar Carp Labeo dussumieri as revealed by Allozymes, Microsatellites and RAPD
The population structure of Labeo dussumieri, an endangered and endemic cyprinid from
three riverine locations in the Western Ghats, India was investigated using allozyme, microsatellite
and RAPD markers. L. dussumieri samples were obtained from Meenachil, Manimala and Pamba
River basins, Kerala. Fourteen (46.7%) out of 30 allozyme loci, seven microsatellite loci and 12
RAPD Operon decamers gave polymorphic pattern. Six allozyme loci (AAT-2*, EST-4*, GLDH*,
GPI-2*, G6PDH* and LDH-2*) and three microsatellite loci (LdussG1, MFW19 and Bgon22)
exhibited consistent significant deviation from Hardy-Weinberg Equilibrium expectations in
different populations after probability level (P<0.05) was adjusted for sequential Bonferroni
correction. All the three marker types demonstrated concordant results and various estimates
revealed genetic variability within the subpopulations but surprisingly low level (= 0.0034 to
0.0081) of genetic differentiation among L. dussumieri from different river samples. AMOVA
analysis also indicated low differentiation among subpopulations. No evidence for a recent genetic
bottleneck was observed in L. dussumieri populations based on allozyme and microsatellite data
set analysis. Meenachil, Manimala and Pamba Rivers open in to the southern end of Vembanad
Lake in Kerala and are connected to each other in the lower reaches through an extensive network
of natural canals. Common ancestry in the prehistoric period; and possible mixing of fish
populations resulting in high gene flow across the rivers through the lake and interconnecting
canals could have been responsible for the lack of significant allelic heterogeneity among the
L. dussumieri populations. The stocks from the three rivers do not require different management
strategies and for propagation assisted river ranching programme of this species, large effective
breeding population can be developed by mixing individuals from three river
DNA barcoding Indian marine fishes
DNA barcoding has been adopted as a global bio-identification system for animals in recent years. A major national programme
on DNA barcoding of fish and marine life was initiated in India by the authors during 2006 and 115 species of
marine fish covering Carangids, Clupeids, Scombrids, Groupers, Sciaenids, Silverbellies, Mullids, Polynemids and Silurids
representing 79 Genera and 37 Families from the Indian Ocean have been barcoded for the first time using cytochrome
c oxidase I gene (COI) of the mtDNA. The species were represented by multiple specimens and a total of 397 sequences
were generated. After amplification and sequencing of 707 base pair fragment of COI, primers were trimmed which invariably
generated a 655 base pair barcode sequence. The average Kimura two parameter (K2P) distances within species, genera,
families, orders were 0.30%, 6.60%, 9.91%, 16.00%, respectively. In addition to barcode-based species identification
system, phylogenetic relationships among the species have also been attempted. The neighbour-joining tree revealed
distinct clusters in concurrence with the taxonomic status of the species
Identification of polymorphic allozyme markers for population structure analysis in Horabagrus brachysoma (Gunther, 1864).
Fourteen polymorphic allozyme loci were identified in yellow catfish, Horabagrus
brachysoma. The genetic variation detected at each allozyme locus was assessed
for samples collected from three rivers. The observed heterozygosities per locus
ranged from 0.0286 to 0.4000. Significant genotype heterogeneity indicated that
the samples are not drawn from same gene pool. The results suggest the potential
of the identified loci to analyze stock structure of natural populations of
H. brachysoma
Framing international trade and chronic disease
There is an emerging evidence base that global trade is linked with the rise of chronic disease in many low and middle-income countries (LMICs). This linkage is associated, in part, with the global diffusion of unhealthy lifestyles and health damaging products posing a particular challenge to countries still facing high burdens of communicable disease. We developed a generic framework which depicts the determinants and pathways connecting global trade with chronic disease. We then applied this framework to three key risk factors for chronic disease: unhealthy diets, alcohol, and tobacco. This led to specific 'product pathways', which can be further refined and used by health policy-makers to engage with their country's trade policy-makers around health impacts of ongoing trade treaty negotiations, and by researchers to continue refining an evidence base on how global trade is affecting patterns of chronic disease. The prevention and treatment of chronic diseases is now rising on global policy agendas, highlighted by the UN Summit on Noncommunicable Diseases (September 2011). Briefs and declarations leading up to this Summit reference the role of globalization and trade in the spread of risk factors for these diseases, but emphasis is placed on interventions to change health behaviours and on voluntary corporate responsibility. The findings summarized in this article imply the need for a more concerted approach to regulate trade-related risk factors and thus more engagement between health and trade policy sectors within and between nations. An explicit recognition of the role of trade policies in the spread of noncommunicable disease risk factors should be a minimum outcome of the September 2011 Summit, with a commitment to ensure that future trade treaties do not increase such risks
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