971 research outputs found
Focusing a fountain of neutral cesium atoms with an electrostatic lens triplet
An electrostatic lens with three focusing elements in an alternating-gradient
configuration is used to focus a fountain of cesium atoms in their ground
(strong-field-seeking) state. The lens electrodes are shaped to produce only
sextupole plus dipole equipotentials which avoids adding the unnecessary
nonlinear forces present in cylindrical lenses. Defocusing between lenses is
greatly reduced by having all of the main electric fields point in the same
direction and be of nearly equal magnitude. The addition of the third lens gave
us better control of the focusing strength in the two transverse planes and
allowed focusing of the beam to half the image size in both planes. The beam
envelope was calculated for lens voltages selected to produced specific
focusing properties. The calculations, starting from first principles, were
compared with measured beam sizes and found to be in good agreement.
Application to fountain experiments, atomic clocks, and focusing polar
molecules in strong-field-seeking states is discussed.Comment: 8 pages 10 figure
Diversity of wetland fish and its impact on the income of fishermen community of Assam.
A survey was conducted in 3000 fishermen households surrounding 54 wetlands (Beels) of Assam. The fish diversity of the wetlands has been decreasing during the last few years due to some extrinsic and intrinsic factors. The total number of fish species recorded so far during the present study is 67 belonging to 21 families. Cyprinidae is the most dominant family represented by major group species (8), intermediate group species (3) and minor group species (12) of high commercial value. Among these three groups, the diversity of fish species is higher in the minor group fish. The present paper deals with the economic condition of the fishermen who mainly fish in the wetlands. The economic condition of the fishermen community is found very poor. The income of fishermen varies from Rs. 4.478 to Rs.7,484 per annum. A regression analysis shows that the income of fishermen is not dependent alone on the fish production but it is exclusively dependent on the value of the fish catch. All the three groups (in terms of value) have significant influence at 10.00% confidence level. But analysis of β shows that the intermediate fish group exhibits the highest influence on the variation of the fishermen income followed by minor and major group respectively
Research Notes : India : Effect of dates of planting on five soybean varieties
Assam is one of the seven states comprising the North Eastern region of India. The plains of the Brahmaputra Valley lie between 24° to 28° N Latitude, 90° to 96° East Longitude and its elevation (above M.S.L.) ranges from 35 m (Dhubri) to 106 m (Dibrugarh). Soybean was introduced in Assam in 1975 through the Soy~ean Research Project sponsored by the Indian Council of Agriculture Research, New Delhi
Optimization of dilution rate for the production of value added product and simultaneous reduction of organic load from pineapple cannery waste
Candida utiilis NRRL Y-900 was grown on pineapple cannery waste as the sole carbon
and energy source in a chemostat at dilution rates ranging between 0.05 and 0.65 h–1 to determine
the growth kinetics. The cell yield coefficient varied with dilution rate and a maximum value of
0.662 ± 0.002 gx/gcarb was obtained at a dilution rate of 0.4 h–1. At steady state, the concentrations of
carbohydrate, reducing sugar, and chemical oxygen demand (COD) appeared to follow Monod
kinetics. At maximum specific growth rate ( max) 0.65 h–1, the saturation constants for
carbohydrate, reducing sugar and COD were 0.51 ± 0.02 gcarb/1, 0.046 ± 0.003 grs/1, and 1.036 ±
0.001 gCOD/1, respectively. Maximum biomass productivity (Q x max) 2.8 ± 0.03 gx/1 h was obtained
at a dilution rate of 0.5 h–1. At this dilution rate, only 71.0 ± 0.41% COD was removed whereas at a
dilution rate of 0.1 h–1, 98.2 ± 0.35% reduction in COD was achieved. At a dilution rate of 0.4 h–1,
the optimal yeast productivity and reduction in COD were 2.7 ± 0.13 gp/1 h, and 84.2 ± 0.42%,
respectively.
Biomass - Candida utilis - chemostat - continuous culture - growth kinetics - pineapple cannery
waste - steady stat
Causes of fish depletion: a factor analysis approach
A study was conducted in 54 wetlands of 13 districts of Assam, India to evaluate the causes of fish depletion. Twenty-two variables were considered for the study. Seven factors were extracted through factor analysis (Principal Component Analysis) based on Eigen Value Criteria of more than one. These seven factors together accounted for 69.3% of the total variance. Based on the characteristics of the variables, all the factors were given descriptive names. These variables can be used to measure the extent of management deficiency of the causes of fish depletion in the wetlands. The factors are management deficiency, organic load interference, catchment condition, extrinsic influence, fishermen’s ignorance, external environment and aquaculture program. Management deficiency accounted for a substantial portion of the total variance
Nonlinear dynamics in an alternating gradient guide for neutral particles
Neutral particles can be guided and focussed using electric field gradients
that focus in one transverse direction and defocus in the other, alternating
between the two directions. Such a guide is suitable for transporting particles
that are attracted to strong electric fields, which cannot be guided using
static fields. Particles are only transmitted if their initial positions and
transverse speeds lie within the guide's phase space acceptance. Nonlinear
forces are always present in the guide and can severely reduce this acceptance.
We consider the effects of the two most important nonlinear forces, a term in
the force that is cubic in the off-axis displacement, and a nonlinear term
which couples together the two transverse motions. We use approximate
analytical techniques, along with numerical methods, to calculate the influence
of these nonlinear forces on the particle trajectories and on the phase space
acceptance. The cubic term alters the focussing and defocussing powers, leading
either to an increase or a decrease of the acceptance depending on its sign. We
find an approximate analytical result for the phase space acceptance including
this cubic term. Using a perturbation method we show how the coupling term
leads to slow changes in the amplitudes of the transverse oscillations. This
term reduces the acceptance when it reduces the focussing power, but has little
influence when it increases that power. It is not possible to eliminate both
nonlinear terms, but one can be made small at the expense of the other. We show
how to choose the guide parameters so that the acceptance is optimized.Comment: 31 pages, 12 figure
INVESTIGATING THE ROLE OF NF-κB, COX-1, COX-2, COMT, IL-10, IL-6 AND TNF-α IN MODULATING ANTI-NOCICEPTIVE ACTIVITY OF METHANOLIC EXTRACT OF ENTADA PHASEOLOIDES
Objective: To investigate the analgesic activity of methanolic extract of Entada phaseoloides (MEEP) along with its molecular mechanistic pathway.
Methods: Swiss albino female mice and Wistar rats of either sex were administered orally with MEEP extracts (100, 200 and 400 mg/kg) and pentazocine, tramadol and diclofenac sodium, as standard drugs. Following administration, anti-nociceptive activity was evaluated using an acetic acid-induced writhing test, Eddy’s hot plate, and hot water immersion test. Serum was collected for molecular expression of various proteins and genes using Reverse Transcriptase PCR and Western Blotting.
Results: Acetic acid writhing test, a frequently used method to assess peripheral analgesic activity, revealed that MEEP reduced peripherally induced pain in a dose-dependent manner. Likewise, Eddy’s hot plate and hot water immersion methods, often implicated for testing central analgesic activities, showed that MEEP is bestowed with the capability to counteract analgesia in a dose and time-dependent manner. Pro-inflammatory cytokines and factors like COX-2, IL-6, TNF-α, and NF-κB that cause inflammatory responses and pain were significantly reduced, suggesting its analgesic and anti-inflammatory potential. This analgesic and the anti-inflammatory role played by MEEP is also supported by the up-regulation of anti-inflammatory cytokine IL-10 and COMT and COX-1 enzyme demonstrated no significant difference between the groups.
Conclusion: The study revealed the weak peripheral and potent central analgesic property MEEP by modulating pro-inflammatory and anti-inflammatory pathways
Synopsis of marine prawn fishery of India-1981
Prawn landings and percentage contributions of different maritime states in India mainly Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu, Pondicherry, Andhra Pradesh, Orissa, West Bengal and Andamans were studied during 1980 and 1981.The penaeid and non-penaeid prawn landings of the same period in these states were also recorded. Monthlv prawn landings, Penaeid and non-penaeid prawn landings in these states during the year 1981 were studied.Species wise break up of prawn landings and percentages during 1981 were recorded in the present paper. Annual percentage distribution datas of important species in the prawn landings at different centres are given.Prawn landings by commercial shrimp trawlers in relation to the total prawn catch and the fishing effort during 1981 were studied and recorded. Catch trend, species composition and size distribution of important species of prawns at Veraval,Bombay, Karwar, MaIpe and Mangalore, Calicut and Cochin,Neendakara, Waltair, Puri, Kakinada, Tuticorin, Mandapam and Madras during 1981 were extensively studied and recorded. Distribution of the spawning population of important species at selected centres during 1981 were also given
Larval rearing of seahorse Hippocampus kuda under laboratory conditions
Seahorse belongs to a single genus Hippocampus
of the family Syngnathidae. This family
also includes pipefishes and pipehorses. There
are about 30-40 species of seahorses under the
genus Hippocampus. They constitute a fascinating
group of fishes with their unusual body
shape apart from their peculiar mode of reproduction
with the males incubating the fertilised
eggs in a brood pouch on the abdomen. They
are tropical and sub tropical in distribution and
are exploited around the world for use in medicines,
as ornamental fishes, curios and to a very
limited extent as food. Most of them are marine,
inhabiting coral reefs and sea grass beds
though some occur in coastal mangroves
Evaluation of sampling gear for demersal resource surveys
The three demersal trawls evaluated were 38 m HSDT-II, indigenously developed
by CIFT for deep sea fishing in Indian EEZ; and two imported designs, viz.,
45.6 m Expo model demersal trawl and 50 m fish trawl operated from vessels of FSI
and IFP, respectively. Vertical opening at trawl mouth was heighest for 50 m fish
trawl (3.2 m), followed by Expo model demersal trawl (2.5 m) and 38 m HSDT-II
(2.2 m), due to differences in overall dimensions and design features. Estimate of
horizontal opening between otter boards was highest for 38 m HSDT-II probably due
to low drag of the gear, followed by 45.6 m and 50 m trawls. Lowest catch per unit
effort obtained by 38 m HSDT-II is presumably due to smaller dimensions of the gear,
larger codend mesh size and difference in ground rig, in addition to chance factors.
However, 38 m HSDT-II scores on several features desirable in demersal sampling
gear such as simplicity in design and construction, ease of operation; lower twine
surface area and drag; and ground rig suitable for wider range of bottom conditions.
Modifications to make it more effective while sampling for crustaceans and small sized
finfish components are described
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