661 research outputs found
Etude Comparative de lâeffet de Souches de Champignons Mycorhiziens Arbusculaires sur la Croissance et la Nutrition MinĂ©rale du SĂ©same CultivĂ© au SĂ©nĂ©gal
La croissance et la nutrition minĂ©rale de huit variĂ©tĂ©s locales de SĂ©same (Sesamum indicum L.) ont Ă©tĂ© Ă©valuĂ©es en rĂ©ponse Ă lâinoculation mycorhizienne arbusculaire. Les essais conduits en serre pendant trois mois, ont montrĂ© un meilleur dĂ©veloppement et une meilleure nutrition minĂ©rale chez les plants inoculĂ©s comparĂ© aux tĂ©moins non inoculĂ©s. Les variĂ©tĂ©s testĂ©es se sont rĂ©vĂ©lĂ©es trĂšs dĂ©pendantes de la mycorhization arbusculaire. Le degrĂ© de dĂ©pendance est gĂ©nĂ©ralement supĂ©rieur Ă 55 % et est fortement corrĂ©lĂ© Ă lâisolat fongique et Ă la variĂ©tĂ© testĂ©e. Il ressort de cette Ă©tude que les biofertilisants Ă base de champignons mycorhiziens procurent des bĂ©nĂ©fices importants Ă la plante, et peuvent ĂȘtre utilisĂ©s pour amĂ©liorer la croissance et le rendement du sĂ©same.Mots ClĂ©s: Biofertilisation, Mycorhizienne, Sesamum indicumThe growth and mineral nutrition of eight local varieties of Sesame (Sesamum indicum L.) were evaluated in response to arbuscular mycorrhiza inoculation in a greenhouse. There was greater plant growth and better mineral nutrition in inoculated pots compared to non-inoculated controls. The varieties tested showed high dependence on arbuscular mycorrhiza. The degree of dependence was generally greater than 55% and was highly correlated with the fungal isolates and variety tested. It is evident that mycorrhizae fungi-based biofertilisers provide significant benefits to the plant and can be used to improve growth and yield in sesame.Keywords: Biofertilisation, Mycorrhiza, Sesamum indicu
Electron-phonon coupling and its evidence in the photoemission spectra of lead
We present a detailed study on the influence of strong electron-phonon
coupling to the photoemission spectra of lead. Representing the strong-coupling
regime of superconductivity, the spectra of lead show characteristic features
that demonstrate the correspondence of physical properties in the normal and
the superconducting state, as predicted by the Eliashberg theory. These
features appear on an energy scale of a few meV and are accessible for
photoemission only by using modern spectrometers with high resolution in energy
and angle.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let
Effect of an Outpatient Education Program on Knowledge and Healthy Behavior Change of Patients Who Have Undergone Percutaneous Transluminal Coronary Angioplasty
72 leavesAn outpatient education program for patients who have undergone percutaneous transluminal coronary angioplasty was evaluated to determine if there was an increase in knowledge of a change in healthy behaviors as a
result of the program. The sample consisted of 48 patients; 24 who experienced an outpatient
education program and 24 who did not. Three instruments developed by the investigator were used. Both groups completed a demographics form, a knowledge assessment form and a lifestyle assessment form before the program
began. The knowledge assessment form and lifestyle assessment form were completed again six weeks after the program.
Both groups showed a statistically significant increase in knowledge
(p<.05). The experimental group showed a statistically significant increase in
exercise behavior (p<.05). Because both groups showed a statistically significant increase in knowledge, this change could not be attributed to the program. Only the experimental group showed an increase in healthy behaviors, however. Therefore, the education program was effective in influencing patients to become more responsible for their treatment and care
The high-pressure alpha/beta phase transition in lead sulphide (PbS): X-ray powder diffraction and quantum mechanical calculations
The high-pressure behaviour of PbS was investigated by angular dispersive
X-ray powder diffraction up to pressures of 6.8 GPa. Experiments were
accompanied by first principles calculations at the density functional theory
level. By combining both methods reliable data for the elastic properties of
rock-salt type alpha- and high-pressure beta-PbS could be obtained. beta-PbS
could be determined to crystallise in the CrB-type (B33), with space group
Cmcm. The reversible ferro-elastic alpha/beta transition is of first order. It
is accompanied by a large volume discontinuity of about 5% and a coexistence
region of the two phases. A gliding mechanism of {001} bilayers along one of
the cubic -directions governs the phase transition which can be described
in terms of group/subgroup relationships via a common subgroup, despite its
reconstructive character. The quadrupling of the primitive unit cell indicates
a wave vector (0,0,pi/a) on the Delta-line of the Brillouin zone.Comment: 7 pages, 5 figures, 3 tables submitted to EP
Signature of quantum criticality in photoemission spectroscopy at elevated temperature
A quantum phase transition (QPT) in a heavy-fermion (HF) compound may destroy
the Fermi liquid groundstate. However, the conditions for this breakdown have
remained obscure. We report the first direct investigation of heavy
quasiparticle formation and breakdown in the canonical system
CeCuAu by ultraviolet photoemission spectroscopy at elevated
temperatures without the complications of lattice coherence. Surprisingly, the
single-ion Kondo energy scale exhibits an abrupt step near the quantum
critical Au concentration of . We show theoretically that this step is
expected from a highly non-linear renormalization of the local spin coupling at
each Ce site, induced by spin fluctuations on neighboring sites. It provides a
general high-temperature indicator for HF quasiparticle breakdown at a QPT.Comment: Published version, PRL, minor changes in wordin
Experimental study of slow sand filtration for the treatment of various wastewaters in tropical environment
Wastewater treatment by slow sand filtration is a biological process which consists in filtering wastewater through a porous media. The objective of this study was to evaluate the performances of this biotechnology under tropical climate. Three sand filters were monitored at ONAS (CambérÚne wastewater treatment plant in Dakar, Senegal). The filters were built with local materials, and were constituted with a feeding tank of approximately 180 litters, a column (two meters high and 30-25 cm diameter). The filters were filled with sand (75 cm), gravel (25 cm) and wastewater (90 cm). The results showed that with sand of d10 equal to 0.58 mm and flow rate of 0.05 m/h, the filtration cycle was relatively long for the first run with pretreated wastewater. At the level of the primary settling tank, with flow a rate of 0.08 m/h, the removal rates were about 12.75%, 16.31%, 12.92%, 5.45%, 7.09% and 10.50% for TSS, COD, BOD5, nitrogen phosphorus and faecal coliforms respectively. At the level of the clarifier, with a filtration of 0.15 m/h, the removals were 1.4% for TSS, 1.84% for COD, 1.09% for BOD5 11.38% for nitrogen, 5.18% for phosphorus and 1.74% of faecal coliforms.Keywords: Flow rate; filtration cycle, removal; sand filtration; tropical climate, wastewater
Comparing variant calling algorithms for target-exon sequencing in a large sample
Abstract
Background
Sequencing studies of exonic regions aim to identify rare variants contributing to complex traits. With high coverage and large sample size, these studies tend to apply simple variant calling algorithms. However, coverage is often heterogeneous; sites with insufficient coverage may benefit from sophisticated calling algorithms used in low-coverage sequencing studies. We evaluate the potential benefits of different calling strategies by performing a comparative analysis of variant calling methods on exonic data from 202 genes sequenced at 24x in 7,842 individuals. We call variants using individual-based, population-based and linkage disequilibrium (LD)-aware methods with stringent quality control. We measure genotype accuracy by the concordance with on-target GWAS genotypes and between 80 pairs of sequencing replicates. We validate selected singleton variants using capillary sequencing.
Results
Using these calling methods, we detected over 27,500 variants at the targeted exons; >57% were singletons. The singletons identified by individual-based analyses were of the highest quality. However, individual-based analyses generated more missing genotypes (4.72%) than population-based (0.47%) and LD-aware (0.17%) analyses. Moreover, individual-based genotypes were the least concordant with array-based genotypes and replicates. Population-based genotypes were less concordant than genotypes from LD-aware analyses with extended haplotypes. We reanalyzed the same dataset with a second set of callers and showed again that the individual-based caller identified more high-quality singletons than the population-based caller. We also replicated this result in a second dataset of 57 genes sequenced at 127.5x in 3,124 individuals.
Conclusions
We recommend population-based analyses for high quality variant calls with few missing genotypes. With extended haplotypes, LD-aware methods generate the most accurate and complete genotypes. In addition, individual-based analyses should complement the above methods to obtain the most singleton variants.http://deepblue.lib.umich.edu/bitstream/2027.42/110906/1/12859_2015_Article_489.pd
Comparing variant calling algorithms for target-exon sequencing in a large sample
Abstract
Background
Sequencing studies of exonic regions aim to identify rare variants contributing to complex traits. With high coverage and large sample size, these studies tend to apply simple variant calling algorithms. However, coverage is often heterogeneous; sites with insufficient coverage may benefit from sophisticated calling algorithms used in low-coverage sequencing studies. We evaluate the potential benefits of different calling strategies by performing a comparative analysis of variant calling methods on exonic data from 202 genes sequenced at 24x in 7,842 individuals. We call variants using individual-based, population-based and linkage disequilibrium (LD)-aware methods with stringent quality control. We measure genotype accuracy by the concordance with on-target GWAS genotypes and between 80 pairs of sequencing replicates. We validate selected singleton variants using capillary sequencing.
Results
Using these calling methods, we detected over 27,500 variants at the targeted exons; >57% were singletons. The singletons identified by individual-based analyses were of the highest quality. However, individual-based analyses generated more missing genotypes (4.72%) than population-based (0.47%) and LD-aware (0.17%) analyses. Moreover, individual-based genotypes were the least concordant with array-based genotypes and replicates. Population-based genotypes were less concordant than genotypes from LD-aware analyses with extended haplotypes. We reanalyzed the same dataset with a second set of callers and showed again that the individual-based caller identified more high-quality singletons than the population-based caller. We also replicated this result in a second dataset of 57 genes sequenced at 127.5x in 3,124 individuals.
Conclusions
We recommend population-based analyses for high quality variant calls with few missing genotypes. With extended haplotypes, LD-aware methods generate the most accurate and complete genotypes. In addition, individual-based analyses should complement the above methods to obtain the most singleton variants.http://deepblue.lib.umich.edu/bitstream/2027.42/134735/1/12859_2015_Article_489.pd
Temperature dependence of the Kondo resonance and its satellites in CeCu_2Si_2
We present high-resolution photoemission spectroscopy studies on the Kondo
resonance of the strongly-correlated Ce system CeCuSi. Exploiting the
thermal broadening of the Fermi edge we analyze position, spectral weight, and
temperature dependence of the low-energy 4f spectral features, whose major
weight lies above the Fermi level . We also present theoretical
predictions based on the single-impurity Anderson model using an extended
non-crossing approximation (NCA), including all spin-orbit and crystal field
splittings of the 4f states. The excellent agreement between theory and
experiment provides strong evidence that the spectral properties of
CeCuSi can be described by single-impurity Kondo physics down to K.Comment: 4 pages, 3 figure
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