2,981 research outputs found
Ultrasensitive interplay between ferromagnetism and superconductivity in NbGd composite thin films
A model binary hybrid system composed of a randomly distributed rare-earth
ferromagnetic (Gd) part embedded in an s-wave superconducting (Nb) matrix is
being manufactured to study the interplay between competing superconducting and
ferromagnetic order parameters. The normal metallic to superconducting phase
transition appears to be very sensitive to the magnetic counterpart and the
modulation of the superconducing properties follow closely to the
Abrikosov-Gorkov (AG) theory of magnetic impurity induced pair breaking
mechanism. A critical concentration of Gd is obtained for the studied NbGd
based composite films (CFs) above which superconductivity disappears. Besides,
a magnetic ordering resembling the paramagnetic Meissner effect (PME) appears
in DC magnetization measurements at temperatures close to the superconducting
transition temperature. The positive magnetization related to the PME emerges
upon doping Nb with Gd. The temperature dependent resistance measurements
evolve in a similar fashion with the concentration of Gd as that with an
external magnetic field and in both the cases, the transition curves accompany
several intermediate features indicating the traces of magnetism originated
either from Gd or from the external field. Finally, the signatures of magnetism
appear evidently in the magnetization and transport measurements for the CFs
with very low (less than 1 at. %) doping of Gd
A novel multiplex PCR system for the detection of virulence associated genes of E. coli O157:H7 from food system
In view of the importance E. coli serotype 0157:H7 in human diseases, an easy and quick system is desirable to detect toxin producing strains. In this report, we describe standardization of a novel multiplex Polymerase Chain Reaction (mPCR) assay for simultaneous detection of four important genes associated with the organism E. coli 0157:H7 viz., stx 1, stx 2, eae A, hly A along with an internal amplification control (IAC). The mPCR method developed in the present study is sensitive enough to detect cells as low as 103 CFU ml-1 or g-1 of the food samples. The E. coli 0157:H7 strains having been identified to contain the gene in the mPCR were unequivocally detected positive for the serological and conventional culture method. As E. coli 0157:H7 is qualified as biowarfare agent; this mPCR system is of immense help in detecting them during emergencies of biological war and suspected outbreaks. 
Characterization of partially purified β-galactosidase from Bacillus Sp MTCC-864
β-Galactosidase is an important enzyme for the hydrolysis of lactose in milk and other by-products of dairy industry such as whey and for the synthesis of galacto-oligosaccharides known for their prebiotic properties. In the present study we report the extraction, partial purification and characterization of intracellular β-galactosidase from Bacillus sp MTCC-864. The media containing tryptone, yeast extract and lactose was used for growth and enzyme production. The enzyme was extracted through ammonium sulphate fractionation and gel permeation chromatography technique using Sephacryl-200. Optimum enzyme activity was found at 50oC and pH 7.0. Further enzyme activity was enhanced in the presence of divalent metal ions such as Mg++ and Mn++, while it was inhibited by EDTA. The enzyme was thermostable and retained 70% of its original activity after 30min of incubation at 60oC. These properties of enzyme indicate its potential use for hydrolysis of lactose in milk and whey from the dairy industry
Linking Human Health to Biological Diversity
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74648/1/j.1523-1739.1997.0110061459.x.pd
Delineating meta-quantitative trait loci for anthracnose resistance in common bean (Phaseolus vulgaris L.)
Anthracnose, caused by the fungus Colletotrichum lindemuthianum, is one of the devastating disease affecting common bean production and productivity worldwide. Several quantitative trait loci (QTLs) for anthracnose resistance have been identified. In order to make use of these QTLs in common bean breeding programs, a detailed meta-QTL (MQTL) analysis has been conducted. For the MQTL analysis, 92 QTLs related to anthracnose disease reported in 18 different earlier studies involving 16 mapping populations were compiled and projected on to the consensus map. This meta-analysis led to the identification of 11 MQTLs (each involving QTLs from at least two different studies) on 06 bean chromosomes and 10 QTL hotspots each involving multiple QTLs from an individual study on 07 chromosomes. The confidence interval (CI) of the identified MQTLs was found 3.51 times lower than the CI of initial QTLs. Marker-trait associations (MTAs) reported in published genome-wide association studies (GWAS) were used to validate nine of the 11 identified MQTLs, with MQTL4.1 overlapping with as many as 40 MTAs. Functional annotation of the 11 MQTL regions revealed 1,251 genes including several R genes (such as those encoding for NBS-LRR domain-containing proteins, protein kinases, etc.) and other defense related genes. The MQTLs, QTL hotspots and the potential candidate genes identified during the present study will prove useful in common bean marker-assisted breeding programs and in basic studies involving fine mapping and cloning of genomic regions associated with anthracnose resistance in common beans
Constraints on the Charged Higgs Sector from the Tevatron Collider Data on Top Quark Decay
The top quark data in the lepton plus channel offers a viable probe
for the charged Higgs boson signal. We analyse the recent Tevatron collider
data in this channel to obtain a significant limit on the mass in the
large region.Comment: 8 pages, LaTeX file; 2 figures included (PS files
In-Network Outlier Detection in Wireless Sensor Networks
To address the problem of unsupervised outlier detection in wireless sensor
networks, we develop an approach that (1) is flexible with respect to the
outlier definition, (2) computes the result in-network to reduce both bandwidth
and energy usage,(3) only uses single hop communication thus permitting very
simple node failure detection and message reliability assurance mechanisms
(e.g., carrier-sense), and (4) seamlessly accommodates dynamic updates to data.
We examine performance using simulation with real sensor data streams. Our
results demonstrate that our approach is accurate and imposes a reasonable
communication load and level of power consumption.Comment: Extended version of a paper appearing in the Int'l Conference on
Distributed Computing Systems 200
Assessing long term impact of nutrient management and rainfall variability on the agroecological resilience of maize (Zea mays)- wheat (Triticum aestivum) system in NW India
A long-term (2000-2010) field experiment was carried out in the lower Shiwalik foothills of Punjab to study the carry over effect of organic manures and fertilizers on the productivity of maize (Zea mays L.)- wheat (Triticum aestivum L.) cropping system for efficient N management and resource use under rainfed conditions and to develop predictive models describing relationship between yields and seasonal rainfall. N management strategies involving combined application of 15 kg N/ha either through compost or leucaena loppings along with 20 kg N/ha through inorganic fertilizer for maize-wheat cropping sequence utilized growth resources most efficiently and maintained stable yield performance culminating in significantly higher system productivity, better resource use efficiencies and sustainable yield index, suggesting partial N substitution through compost or locally available plant material. The regression models developed to predict the effects of N sources on crop yields using monthly rainfall would be of interest to estimate the yield at a given level of rainfall with the likely fluctuation (as error) particularly under rainfed conditions
Charged Higgs production from SUSY particle cascade decays at the LHC
We analyze the cascade decays of the scalar quarks and gluinos of the Minimal
Supersymmetric extension of the Standard Model, which are abundantly produced
at the Large Hadron Collider, into heavier charginos and neutralinos which then
decay into the lighter ones and charged Higgs particles, and show that they can
have substantial branching fractions. The production rates of these Higgs
bosons can be much larger than those from the direct production mechanisms, in
particular for intermediate values of the parameter , and could
therefore allow for the detection of these particles. We also discuss charged
Higgs boson production from direct two-body top and bottom squark decays as
well as from two- and three-body gluino decays.Comment: 30 pages with 10 figures, latex. Uses axodraw.sty and epsfig.st
Higgs Physics at Future Colliders: recent theoretical developments
I review the physics of the Higgs sector in the Standard Model and its
minimal supersymmetric extension, the MSSM. I will discuss the prospects for
discovering the Higgs particles at the upgraded Tevatron, at the Large Hadron
Collider, and at a future high--energy linear collider with
centre--of--mass energy in the 350--800 GeV range, as well as the possibilities
for studying their fundamental properties. Some emphasis will be put on the
theoretical developments which occurred in the last two years.Comment: 20 pages, latex, 12 figures. Talk given at PASCOS 2003 (Bombay,
India
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