1,763 research outputs found
Tolerance in chickpea to Meloidogyne javanica
Quarante-sept cultivars de pois chiche ont été testés pour leur résistance ou leur tolérance envers #Meloidogyne javanica en notant leur croissance dans des sols infestés et des sols sans nématodes. En se fondant sur le nombre de galles, la taille de celles-ci, la surface des racines occupée par les galles et le nombre de masses d'oeufs produites, tous les cultivars paraissent sensibles. L'infestation par le nématode provoque un nanisme, un jaunissement, un dessèchement précoce et une chute des feuilles. Une analyse de régression démontre que la hauteur des plants, le poids des pieds, celui des racines et celui des gousses diminuent lorsque l'infestation augmente. La floraison de deux cultivars tardifs, Pant G 114 et Phule G 1, est retardée dans les sols infestés tandis que chez les cultivars précoces cette floraison est soit avancée soit indifférente à l'infestation par le nématode. Le rapport du poids des racines dans les sols infestés et non infestés - seuil de tolérance - démontre que les cultivars Pant G 114, Phule G 1, GNG 146 et Annigini n'ont qu'un faible niveau de tolérance à #M. javanica. Le niveau de tolérance des cultivars Bheema, N 31 et N 39 est d'environ 4,0 oeufs/gr-1 de sol. Dans un sol infesté, l'absorption de calcium par le cultivar tolérant N 31 est plus élevée que par le cultivar non tolérant Phule G 1. Dans un champ infesté par une population mixte de #M. javanica et #M. incognita, les performances des cultivars tolérants prometteurs N 31, N 59, ICCC 42 et de la lignée de croisement ICCV 90043 se sont révélées meilleures que celles des autres génotypes de pois chiche. (Résumé d'auteur
Effect of super-optimal levels of fertilizers on soil enzymatic activities during growth stages of wheat crop on an Inceptisol
A field experiment was conducted during 2010-2011 and 2011-2012 to investigate the effect of optimal (100% NPK) to super-optimal doses (200% NPK) of mineral fertilizers on soil enzymes such as dehydrogenase (DHA), acid phosphatase (Ac-PA), alkaline phosphatase (Alk-PA), fluorescien diacetate hydrolysis (FDA), urease and nitrate reductase (NRA) at three physiological stages (CRI, anthesis and maturity) of wheat crop on an Inceptisol. Dehydrogenase activity was reduced by 28-37% when fertilizer application was at super-optimal dose (200% NPK), whereas, urease and NRA responded positively in the range of 43-44% and 213-231% respectively. Alk-PAwas 7.3-7.9% higher in treatments receiving 125% NPK as compared to control (100% NPK); whereas, Ac-PA declines in the plots receiving 175 and 200% of recommended dose of fertilizer (RDF) as compared to 150% NPK levels. Addition of 175% RDF increased the FDA to the tune of 46-53% as compared to 100% NPK. A significant (P?0.05) positive interaction between fertilizer treatments and physiological stages of wheat growth was observed on soil enzyme activities (except urease and NRA) being highest at the anthesis stage of wheat. Correlation matrix analysis showed that DHA was correlated with the studied enzyme activities except Ac-PA and FDA; whereas, strong correlation was observed between urease and NRA (r=0.981, P=0.01). This study provides theoretical and practical base for avoiding super optimal application of fertilisers which hinders the enzyme activities and vis-a-vis sustainable nutrient enrichment under rhizosphere
Effects of cetylpyridinium chloride treatment of roast beef on Listeria monocytogenes populations and quality attributes
The effectiveness of cetylpyridinium chloride
(CPC) for reducing microbial populations,
in particular Listeria monocytogenes, on
ready-to-eat roast beef was evaluated. Roast
beef slices inoculated with L. monocytogenes
were dipped in a solution of 1% CPC for 1
minute. Samples were then vacuum packaged
and stored at refrigeration temperature. The
effects of CPC treatment on microbial populations, as well as on color and texture of the roast beef samples, was evaluated over a 42-day period. Immediately after CPC treatment, L. monocytogenes populations were reduced by 99 to 99.99%, with the treatment being somewhat more effective on exterior than on sliced/cut surfaces. Throughout 42 days of refrigerated storage, populations of L. monocytogenes, total bacteria, and lactic acid bacteria remained lower on CPC-treated samples than on non-treated samples. Treatment with CPC did not significantly affect the color or texture of roast beef. Treatment with CPC, especially when applied to products before slicing, may serve as an effective antimicrobial intervention for ready-to-eat meat products
In situ three-dimensional study of corrosion fatigue crack initiation and growth of corroded 7075 aluminum alloys
Corrosion fatigue crack initiation in aluminum alloys can have significant effects on part life. An improved understanding of the mechanisms governing corrosion and corrosion fatigue damage of Al alloys is necessary. Alloy design and environmental chemistry have significant effects on corrosion fatigue crack initiation and growth. Influential alloy design features include alloy chemistry, precipitate structure, and grain structure. Environmental factors such as environmental chemistry and preexisting corrosion damage can also effect the corrosion fatigue behavior of the alloys. To investigate the effects of environment and precipitate size on corrosion fatigue of aluminum alloys, the in situ corrosion fatigue testing of corroded peak-aged and overaged 7075 Al alloys in 3.5 wt% NaCl solution will be presented.
For this study, rolled 7075 Al alloy was heat-treated to peak-aged, overaged, and highly overaged conditions. The samples were machined, mechanically polished, masked, and then soaked in 3.5 wt.% NaCl solution for fifteen days to yield significant corrosion damage in a region of interest. The corroded specimens were fatigue tested in situ in 3.5 wt.% NaCl using synchrotron X-ray tomography to gain three dimensional information regarding fatigue crack initiation and growth characteristics. Hydrogen bubbles were observed within the crack during propagation, indicating chemical changes in the sample during corrosion fatigue. The crack initiation, growth, and bubble evolution were quantified and discussed. A relationship was observed between the bubble volume and crack surface area as the test progressed, which suggested an effect from stress at the crack tip. Ultimately, this in situ study provided new insights regarding the localized processes occurring during the corrosion fatigue cracking of aluminum alloys which previous post-mortem and two dimensional studies were unable to discover
The phylogenetically distinct early human embryo
The phylogenetic singularity of the human embryo remains unresolved as cell types of the human blastocyst have resisted classification. Combining clustering of single cellular transcriptomes and dynamically expressed genes we resolve the cell types. This unveils the missing inner cell mass (ICM) and reveals classical step-wise development. Conversely, numerous features render our blastocyst phylogenetically distinct: unlike mice, our epiblast is self-renewing and we have blastocyst non-committed cells (NCCs), part of an apoptosis-mediated quality control/purging process. At the transcriptome-level all primate embryos are distinct as the pluripotent cell types are uniquely fast evolving. A substantial fraction of gene expression gain and loss events between human and new-world monkeys involve endogenous retrovirus H (ERVH). Human pluripotent cells are unique in which (H)ERVH's are active, the extent to which these modulate neighbour gene expression and their ability to suppress mutagenic transposable elements. Current naive cultures are heterogeneous and both developmentally and phylogenetically "confused"
The effect of socioeconomic deprivation on 12 month Traumatic Brain Injury (TBI) outcome
Objectives: To assess the impact of social deprivation on Traumatic Brain Injury (TBI) global outcome.
Design: The study was a prospective observational study conducted using consecutive admissions with TBI.
Subjects: 1322 consecutive adult patients with TBI were recruited into the study between 2010 and 2015.
Methods: All patients were assessed by the TBI rehabilitation team at both six weeks and 12 months following TBI. Details of the injury and demographic data was collated at six weeks. This included age, gender and ZIP Code. Social deprivation was measured by the Indices of Multiple Deprivation (IMD) Score. The outcome measure used was the Extended Glasgow Outcome Score (GOSE) at 12 months. Univariate analysis was followed by a Multi-Ordinal Regression to evaluate predictor variables.
Results: With regard to the representation of IMD deciles, the study population approximated to the general Sheffield population (p = .139). Within the univariate analysis, statistically significant relationships were noted between IMD and GOSE (p = <.001). The Ordinal Regression revealed a significant relationship between worse GOSE and IMD (p = .002), age (p = .001), GCS (p < .001), alcohol intoxication (p < .001) and Medical Comorbidity (p = .041).
Conclusion: Increasing social deprivation is associated with poorer global TBI outcomes at 12 months
Relic Neutrino Absorption Spectroscopy
Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang
relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption
dips in the neutrino flux to be observed at Earth. The high-energy edges of
these dips are fixed, via the resonance energies, by the neutrino masses alone.
Their depths are determined by the cosmic neutrino background density, by the
cosmological parameters determining the expansion rate of the universe, and by
the large redshift history of the cosmic neutrino sources. We investigate the
possibility of determining the existence of the cosmic neutrino background
within the next decade from a measurement of these absorption dips in the
neutrino flux. As a by-product, we study the prospects to infer the absolute
neutrino mass scale. We find that, with the presently planned neutrino
detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant
energy regime above 10^{21} eV, relic neutrino absorption spectroscopy becomes
a realistic possibility. It requires, however, the existence of extremely
powerful neutrino sources, which should be opaque to nucleons and high-energy
photons to evade present constraints. Furthermore, the neutrino mass spectrum
must be quasi-degenerate to optimize the dip, which implies m_{nu} >~ 0.1 eV
for the lightest neutrino. With a second generation of neutrino detectors,
these demanding requirements can be relaxed considerably.Comment: 19 pages, 26 figures, REVTeX
Search for Short-Term Periodicities in the Sun's Surface Rotation: A Revisit
The power spectral analyses of the Sun's surface equatorial rotation rate
determined from the Mt. Wilson daily Doppler velocity measurements during the
period 3 December 1985 to 5 March 2007 suggests the existence of 7.6 year, 2.8
year, 1.47 year, 245 day, 182 day and 158 day periodicities in the surface
equatorial rotation rate during the period before 1996.
However, there is no variation of any kind in the more accurately measured
data during the period after 1995. That is, the aforementioned periodicities in
the data during the period before the year 1996 may be artifacts of the
uncertainties of those data due to the frequent changes in the instrumentation
of the Mt. Wilson spectrograph. On the other hand, the temporal behavior of
most of the activity phenomena during cycles 22 (1986-1996) and 23 (after 1997)
is considerably different. Therefore, the presence of the aforementioned
short-term periodicities during the last cycle and absence of them in the
current cycle may, in principle, be real temporal behavior of the solar
rotation during these cycles.Comment: 11 pages, 6 figures, accepted for publication in Solar Physic
Theoretical study of lepton events in the atmospheric neutrino experiments at SuperK
Super-Kamiokande has reported the results for the lepton events in the
atmospheric neutrino experiment. These results have been presented for a 22.5kT
water fiducial mass on an exposure of 1489 days, and the events are divided
into sub-GeV, multi-GeV and PC events. We present a study of nuclear medium
effects in the sub-GeV energy region of atmospheric neutrino events for the
quasielastic scattering, incoherent and coherent pion production processes, as
they give the most dominant contribution to the lepton events in this energy
region. We have used the atmospheric neutrino flux given by Honda et al. These
calculations have been done in the local density approximation. We take into
account the effect of Pauli blocking, Fermi motion, Coulomb effect,
renormalization of weak transition strengths in the nuclear medium in the case
of the quasielastic reactions. The inelastic reactions leading to production of
leptons along with pions is calculated in a - dominance model by
taking into account the renormalization of properties in the nuclear
medium and the final state interaction effects of the outgoing pions with the
residual nucleus. We present the results for the lepton events obtained in our
model with and without nuclear medium effects, and compare them with the Monte
Carlo predictions used in the simulation and the experimentally observed events
reported by the Super-Kamiokande collaboration.Comment: 23 pages, 13 figure
Computation of protein geometry and its applications: Packing and function prediction
This chapter discusses geometric models of biomolecules and geometric
constructs, including the union of ball model, the weigthed Voronoi diagram,
the weighted Delaunay triangulation, and the alpha shapes. These geometric
constructs enable fast and analytical computaton of shapes of biomoleculres
(including features such as voids and pockets) and metric properties (such as
area and volume). The algorithms of Delaunay triangulation, computation of
voids and pockets, as well volume/area computation are also described. In
addition, applications in packing analysis of protein structures and protein
function prediction are also discussed.Comment: 32 pages, 9 figure
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