2,823 research outputs found
CARE1, a TY3-gypsy long terminal repeat retrotransposon in the food legume chickpea (Cicer arietinum L)
We report a novel Ty3-gypsy long terminal repeat retrotransposon CARE1 (_Cicer arietinum_ retro-element 1) in chickpea. This 5920-bp AT-rich (63%) element carries 723-bp 5' and 897-bp 3' LTRs respectively flanking an internal region of 4300-bp. The LTRs of CARE1 show 93.9% nucleotide identity to each other and have 4-bp (ACTA) terminal inverted repeats. A 17-bp potential tRNAmet primer binding site downstream to 5' LTR and a 13-bp polypurine tract upstream to 3' LTR have been identified. The order of domains (Gag-proteinase-reverse transcriptase-RNaseH-integrase) in the deduced amino acid sequence and phylogenetic tree constructed using reverse transcriptase sequences places CARE1 in the gypsy group of retrotransposons. Homologues of a number of _cis_-elements including CCAAT, TATA and GT-1 have been detected in the regulatory region or the 5' LTR of CARE1. Transgenic tobacco plants containing 5' LTR:GUS construct show that its 5'-LTR is inactive in a heterologous system under normal as well as tissue culture conditions. Genomic Southern blot experiments using 5’LTR of the element as a probe show that CARE1 or its related elements are present in the genomes of various chickpea accessions from various geographic regions
An Efficient Analytical Solution to Thwart DDoS Attacks in Public Domain
In this paper, an analytical model for DDoS attacks detection is proposed, in
which propagation of abrupt traffic changes inside public domain is monitored
to detect a wide range of DDoS attacks. Although, various statistical measures
can be used to construct profile of the traffic normally seen in the network to
identify anomalies whenever traffic goes out of profile, we have selected
volume and flow measure. Consideration of varying tolerance factors make
proposed detection system scalable to the varying network conditions and attack
loads in real time. NS-2 network simulator on Linux platform is used as
simulation testbed. Simulation results show that our proposed solution gives a
drastic improvement in terms of detection rate and false positive rate.
However, the mammoth volume generated by DDoS attacks pose the biggest
challenge in terms of memory and computational overheads as far as monitoring
and analysis of traffic at single point connecting victim is concerned. To
address this problem, a distributed cooperative technique is proposed that
distributes memory and computational overheads to all edge routers for
detecting a wide range of DDoS attacks at early stage.Comment: arXiv admin note: substantial text overlap with arXiv:1203.240
Simultaneous estimation of atenolol and chlorthalidone in combine tablet dosage form by absorption ratio method using UV-Vis spectrophotometry
A simple, precise, reproducible, accurate, economical and rapid UV-VIS Spectrophotometric method have been developed and validated for the simultaneous estimation of ATN and CTN in tablet dosage form. This paper describes the absorption ratio method as a quantification parameter. The absorption ratio method (ARM) involves measurement of absorbance of sample solution is measured at 240.0 nm (Isobestic Point) and 251.0 nm (? max of CTN) and based on E 1% 1cm values at these wavelengths two set of equations were framed. The developed method obeys the beers law in the concentration range of 40-80g/mL for ATN and 10-50 g/mL for CTN. The recovery studies shows %RSD for ATN 0.21 and for CTN 1.34 by ARM method. The results of analysis have been validated statistically for accuracy, precision, repeatability, specificity and ruggedness. The method was successfully applied to the determination of these drugs in pharmaceutical dosage form
Properties and occurrence rates of exoplanet candidates as a function of host star metallicity from the DR25 catalog
Correlations between the occurrence rate of exoplanets and their host star
properties provide important clues about the planet formation processes. We
studied the dependence of the observed properties of exoplanets (radius, mass,
and orbital period) as a function of their host star metallicity. We analyzed
the planetary radii and orbital periods of over 2800 candidates from
the latest data release DR25 (Q1-Q17) with revised planetary radii
based on ~DR2 as a function of host star metallicity (from the Q1-Q17
(DR25) stellar and planet catalog). With a much larger sample and improved
radius measurements, we are able to reconfirm previous results in the
literature. We show that the average metallicity of the host star increases as
the radius of the planet increases. We demonstrate this by first calculating
the average host star metallicity for different radius bins and then
supplementing these results by calculating the occurrence rate as a function of
planetary radius and host star metallicity. We find a similar trend between
host star metallicity and planet mass: the average host star metallicity
increases with increasing planet mass. This trend, however, reverses for masses
: host star metallicity drops with increasing planetary
mass. We further examined the correlation between the host star metallicity and
the orbital period of the planet. We find that for planets with orbital periods
less than 10 days, the average metallicity of the host star is higher than that
for planets with periods greater than 10 days.Comment: 14 pages, 13 Figures, Accepted for publication in The Astronomical
Journa
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