861 research outputs found
Increasing Maize Tolerance to Drought and Flood with Seed Coating Treatments
The lack of irrigation in regions prone to drought, and flooding due to high rainfall or lack of drainage affects seed viability and the subsequent germination and crop establishment. Seed treatment in the form of coatings shows promise as an effective method to preserve the viability of corn (Zea mays) seeds in drought and flood conditions. Chemical formulations may help improve the seed corn vigor under these stressed conditions. This study examined the efficacy of β-aminobutyric acid [BABA] and N-isopropylacrylamide [NIPA] in inducing drought resistance, as well as the ability of lanolin and linseed oil to provide flood tolerance for seed corn. Germination rates and linear shoot growth measurements were used as indications of seed vigor. Uniform coatings of the treatments were applied to untreated seed corn, and treated seed performance was compared to an uncoated control batch of seeds. Water imbibition, moisture, and temperature were manipulated to replicate drought, flood, and optimal growth conditions. The preliminary results of these experiments indicate that these coatings did not significantly increase the viability during short-terms of stressed conditions. At suboptimal temperatures, uncoated control seeds displayed significantly higher seed vigor and growth rates. Manipulation of coating thickness and/or testing at more intense stress levels may be necessary for coating treatments to exhibit positive effects on corn seed resistance to drought and flood
Association of Intronic Single Nucleotide Polymorphism (SNP) of CALM 1 gene with Osteoarthritis of the Knee in Indian Population: A Case-control Study
Osteoarthritis knee is one of the most prevalent disorders in the Indian subcontinent. The wide prevalence and varying features makes it a disease of disguise. Multiple etiological factors have been described. The most recent is genetic contribution in the causation of the disease. This case control study was conducted in the Department of Orthopaedic Surgery, CSM Medical University, Lucknow in collaboration with IIT, Kanpur. 120 cases and 120 controls were enrolled. Clinico-radiological features were noted and symptomatic clinical scoring was done. Genetic polymorphism in relation to intronic region of CALM 1 gene was studied by DNA extraction, Polymerase chain reaction (PCR) and Restriction fragment length polymorphism (RFLP) method. Statistical analysis was done using Stata software. There was no significant difference between age, sex and BMI among cases and controls (p value > .05). ESR (p value =0.0000), fasting blood sugar (p value= 0.0004) and serum uric acid (p value=0.0001) were significantly different among cases and controls. SNP was found in significantly higher number in cases than controls (p value = .0022). Heterozygosity was found only in 5 cases. Logistic regression has also proved significant association of occurrence of Single Nucleotide Polymorphism (SNP) with disease. CALM-1 gene intronic SNP (rs3213718) is present in Indian population. Occurrence of this SNP is significantly affecting the disease
Discovery of Two New Faint Cataclysmic Variables
We report on the discovery of two new faint cataclysmic variables. The
objects were selected as candidates from two different imaging surveys aimed at
the discovery of such faint systems. One survey used color and variability
while the other used color and H emission as selection criteria. We
present our spectra of the two new variables and discuss their properties. A
discussion of the implication of these discoveries on the space density of
faint cataclysmic variables is presented.Comment: 4 pages, 4 figures. Accepted to A&A letter
Polarised radio pulsations from a new T dwarf binary
Brown dwarfs display Jupiter-like auroral phenomena such as magnetospheric
H emission and coherent radio emission. Coherent radio emission is a
probe of magnetospheric acceleration mechanisms and provides a direct
measurement of the magnetic field strength at the emitter's location, both of
which are difficult to access by other means. Observations of the coldest brown
dwarfs (spectral types T and Y) are particularly interesting as their
magnetospheric phenomena may be very similar to those in gas-giant exoplanets.
Here we present 144 MHz radio and infrared adaptive optics observations of the
brown dwarf WISEP J101905.63+652954.2 made using the LOFAR and Keck telescopes
respectively. The radio data shows pulsed highly circularly polarised emission
which yields a rotation rate of hr. The infrared imaging
reveals the source to be a binary with a projected separation of
mas between components of spectral type T5. and T7.. With a
simple "toy model" we show that the radio emission can in principle be powered
by the interaction between the two dwarfs with a mass-loss rates of at least
times the Jovian value. WISEP J101905.63+652954.2 is interesting because
it is the first pulsed methane dwarf detected in a low radio-frequency search.
Unlike previous gigahertz-frequency searches that were only sensitive to
objects with kiloGauss fields, our low-frequency search is sensitive to surface
magnetic fields of Gauss and above which might reveal the coldest
radio-loud objects down to planetary mass-scales.Comment: Accepted for publication in A&
Recommended from our members
Combating DDoS attacks in the cloud: Requirements, trends, and future directions
An overview of DDoS attacks against cloud targets is presented, together with solution requirements, and a guideline for efficient solutions, leading to a novel multilevel alert-flow. To orchestrate future solutions, we give a vision towards novel "Detection Near Impossible" attacks
The Hawaii Infrared Parallax Program. VI. The Fundamental Properties of 1000+ Ultracool Dwarfs and Planetary-mass Objects Using Optical to Mid-IR SEDs and Comparison to BT-Settl and ATMO 2020 Model Atmospheres
We derive the bolometric luminosities () of 865 field-age
and 189 young ultracool dwarfs (spectral types M6-T9, including 40 new
discoveries presented here) by directly integrating flux-calibrated optical to
mid-IR spectral energy distributions (SEDs). The SEDs consist of low-resolution
( 150) near-IR (0.8-2.5 m) spectra (including new spectra for 97
objects), optical photometry from the Pan-STARRS1 survey, and mid-IR photometry
from the CatWISE2020 survey and Spitzer/IRAC. Our
calculations benefit from recent advances in parallaxes from Gaia, Spitzer, and
UKIRT, as well as new parallaxes for 19 objects from CFHT and Pan-STARRS1
presented here. Coupling our measurements with a new uniform
age analysis for all objects, we estimate substellar masses, radii, surface
gravities, and effective temperatures () using evolutionary
models. We construct empirical relationships for and
as functions of spectral type and absolute magnitude,
determine bolometric corrections in optical and infrared bandpasses, and study
the correlation between evolutionary model-derived surface gravities and
near-IR gravity classes. Our sample enables a detailed characterization of
BT-Settl and ATMO 2020 atmospheric model systematics as a function of spectral
type and position in the near-IR color-magnitude diagram. We find the greatest
discrepancies between atmospheric and evolutionary model-derived
(up to 800 K) and radii (up to 2.0 ) at
the M/L transition boundary. With 1054 objects, this work constitutes the
largest sample to date of ultracool dwarfs with determinations of their
fundamental parameters.Comment: Resubmitted to The Astrophysical Journal (ApJ) after a positive
referee report. 51 pages, 29 figures, 7 tables. Data presented in this work:
https://doi.org/10.5281/zenodo.8315643. Scripts associated with methods:
https://github.com/cosmicoder/HIPPVI-Cod
A technical evaluation of improved animal drawn implements under on-farm conditions
Animals are a major source of agriculture power in India and animal drawn implements have evolved to a high degree of simplicity and perfection over a long period of time..
A Preliminary Observational Search for Circumbinary Disks Around Cataclysmic Variables
Circumbinary (CB) disks have been proposed as a mechanism to extract orbital
angular momentum from cataclysmic variables (CVs) during their evolution. As
proposed by Taam & Spruit, these disks extend outwards to several a.u. and
should be detected observationally via their infrared flux or by absorption
lines in the ultraviolet spectra of the CV. We have made use of archival
HST/STIS spectra as well as our own near-IR imaging to search for observational
evidence of such CB disks in seven CVs. Based on the null result, we place an
upper limit on the column density of the disk of N_H~10^17 cm^-2.Comment: accepted for publication in the Astronomical Journal (July 2004
Suppressed Decays of D_s^+ Mesons to Two Pseudoscalar Mesons
Using data collected near the Ds*+ Ds- peak production energy Ecm = 4170 MeV
by the CLEO-c detector, we study the decays of Ds+ mesons to two pseudoscalar
mesons. We report on searches for the singly-Cabibbo-suppressed Ds+ decay modes
K+ eta, K+ eta', pi+ K0S, K+ pi0, and the isospin-forbidden decay mode Ds+ to
pi+ pi0. We normalize with respect to the Cabibbo-favored Ds+ modes pi+ eta,
pi+ eta', and K+ K0S, and obtain ratios of branching fractions: Ds+ to K+ eta /
Ds+ to pi+ eta = (8.9 +- 1.5 +- 0.4)%, Ds+ to K+ eta' / Ds+ to pi+ eta' = (4.2
+- 1.3 +- 0.3)%, Ds+ to pi+ K0S / Ds+ to K+ K0S = (8.2 +- 0.9 +- 0.2)%, Ds+ to
K+ pi0 / Ds+ to K+ K0S = (5.0 +- 1.2 +- 0.6)%, and Ds+ to pi+ pi0 / Ds+ to K+
K0S < 4.1% at 90% CL, where the uncertainties are statistical and systematic,
respectively.Comment: 9 pages postscript,also available through
http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR
Measurement of the eta-Meson Mass using psi(2S) --> eta J/psi
We measure the mass of the eta meson using psi(2S) --> eta J/psi events
acquired with the CLEO-c detector operating at the CESR e+e- collider. Using
the four decay modes eta --> gamma gamma, 3pi0, pi+pi-pi0, and pi+pi-gamma, we
find M(eta)=547.785 +- 0.017 +- 0.057 MeV, in which the first uncertainty is
statistical and the second systematic. This result has an uncertainty
comparable to the two most precise previous measurements and is consistent with
that of NA48, but is inconsistent at the level of 6.5sigma with the much
smaller mass obtained by GEM.Comment: 10 pages postscript,also available through
http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR
- …