1,825 research outputs found
A comparison of age estimates from sagittal otoliths and the first dorsal spine for cobia (Rachycentron canadum) from the northcentral Gulf of Mexico; Comparacion de la edad estimada con otolitos sagitales y la primera espina dorsal en cobia (Rachycentron canadum) en el norte del Golfo de Mejico
A comparison of age estimates from sagittal otoliths and the first dorsal spine for cobia (Rachycentron canadum) from the northern Gulf of Mexico [abstract]; Comparacion de la edad estimada con otolitos sagitales y la primera espina dorsal en cobia (Rachycentron canadum) en el norte del Golfo de Mejico [resumen]
Amylose content and grain appearance traits in rice genotypes
Amylose content (AC) and grain appearance traits of rice ( Oryza sativa
L.) represent a major problem of rice marketing in many rice
producing areas in the world. In Uganda, cooking, eating and appearance
qualities remain undefined in the rice breeding programme. The
objective this study was to determine amylose content of rice
genotypes, and its relationship with grain appearance traits; and mode
of its inheritance in selected rice genotypes. Forty genotypes were
planted in two seasons (2015B and 2016A), in alpha lattice design at
National Crop Resource Research Institute in Uganda. Seven parents,
involving 3 low and 4 intermediate amylose content genotypes selected
in 2015B season,were crossed in a half diallel,and the F1 were advanced
to F2 generation, which together with parents were planted in the
field. Amylose content (AC), kernel width (KW) and kernel length (K/L)
to width ratio were affected by both genetic effects and genotype by
season (G x S) interactions; while kernel length was mainly affected by
genetic factors. Genotypes were grouped into low, intermediate and high
amylose content categories depending on the environment where the
genotypes were grown. Three genotypes (Namche 1, P62H17 and 1190) had
no significant responsesin amylose content in different growing
seasons, suggesting that these genotypes were stable. Amylose content
correlated weakly and negatively with physical appearance quality
traits of the grain; implying that improvement in amylose content would
not affect grain size and shape.There were significant differences
(P<0.001) among parents for general combining ability (GCA) and
among crosses for specific combining ability (SCA) (P<0.5) for
amylose content; indicating that both additive and non-additive gene
actions were responsible for the inheritance of AC. However, the
variance component of GCA was larger than for the SCA, implying that
the inheritance of amylose content was more conditioned by the additive
gene effect.La teneur en amylose (TA) et les caract\ue9ristiques d\u2019aspect
du grain du riz ( Oryza sativa L.) repr\ue9sentent un probl\ue8me
majeur de commercialisation du riz dans de nombreuses r\ue9gions
productrices de riz dans le monde. En Ouganda, les qualit\ue9s de
cuisson, d\u2019alimentation et d\u2019apparence restent
ind\ue9finies dans le programme d\u2019am\ue9lioration du riz.
L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer la
teneur en amylose des g\ue9notypes de riz et sa relation avec les
caract\ue9ristiques d\u2019apparence du grain; et son mode de
transmission dans des g\ue9notypes de riz s\ue9lectionn\ue9s.
Quarante g\ue9notypes ont \ue9t\ue9 plant\ue9s au cours de deux
saisons (2015B et 2016A), dans la conception de lattice alpha \ue0
National Crop Resource Research Institute en Ouganda. Sept parents,
impliquant 3 g\ue9notypes \ue0 faible teneur en amylose et 4
g\ue9notypes s\ue9lectionn\ue9s lors de la saison 2015B, ont
\ue9t\ue9 crois\ue9s sur un demi-diall\ue8le et les F1 ont
\ue9t\ue9 avanc\ue9s \ue0 la g\ue9n\ue9ration F2, qui a
\ue9t\ue9 plant\ue9e avec les parents sur le terrain. La teneur
en amylose (TA), la largeur du noyau (LN) et le rapport longueur /
longueur du noyau (K / L) sur la largeur \ue9taient affect\ue9s
\ue0 la fois par les effets g\ue9n\ue9tiques et par les
interactions g\ue9notype par saison (G x S); tandis que la longueur
du noyau \ue9tait principalement affect\ue9e par des facteurs
g\ue9n\ue9tiques. Les g\ue9notypes ont \ue9t\ue9
regroup\ue9s en cat\ue9gories de teneur faible, interm\ue9diaire
et \ue9lev\ue9e en amylose, en fonction de l\u2019environnement
o\uf9 les g\ue9notypes ont \ue9t\ue9 cultiv\ue9s. Trois
g\ue9notypes (Namche 1, P62H17 et 1190) n\u2019ont pas eu de
r\ue9ponses significatives concernant la teneur en amylose au cours
de diff\ue9rentes saisons de croissance, ce qui sugg\ue8re que ces
g\ue9notypes \ue9taient stables. La teneur en amylose \ue9tait en
corr\ue9lation faible et n\ue9gative avec les caract\ue9ristiques
de qualit\ue9 de l\u2019apparence physique du grain; ce qui implique
que l\u2019am\ue9lioration de la teneur en amylose
n\u2019affecterait pas la taille et la forme des grains. Il y avait
des diff\ue9rences significatives (p <0,001) entre les parents
pour la capacit\ue9 de combinaison g\ue9n\ue9rale (CCG) et entre
les croisements pour la capacit\ue9 de combinaison sp\ue9cifique
(CCS) (p <0,5) pour la teneur en amylose; indiquant que les actions
g\ue9niques additives et non additives \ue9taient responsables de
la transmission du TA. Cependant, la composante de variance de la CCG
\ue9tait plus importante que celle de la CCS, ce qui implique que la
transmission du contenu en amylose \ue9tait davantage
conditionn\ue9e par l\u2019effet du g\ue8ne additif
Interaction of desulfovibrio desulfuricans biofilms with stainless steel surface and its impact on bacterial metabolism
Aims: To study the influence of some metallic elements of stainless steel 304 (SS 304) on the development and activity of a sulfate-reducing bacterial biofilm, using as comparison a reference nonmetallic material polymethylmethacrylate (PMMA).
Methods and Results: Desulfovibrio desulfuricans biofilms were developed on SS
304 and on a reference nonmetallic material, PMMA, in a flow cell system.
Steady-state biofilms were metabolically more active on SS 304 than on PMMA. Activity tests with bacteria from both biofilms at steady state also showed that the doubling time was lower for bacteria from SS 304 biofilms.
The influence of chromium and nickel, elements of SS 304 composition, was
also tested on a cellular suspension of Des. desulfuricans. Nickel decreased the bacterial doubling time, while chromium had no significant effect.
Conclusions: The following mechanism is hypothesized: a Des. desulfuricans
biofilm grown on a SS 304 surface in anaerobic conditions leads to the weakening
of the metal passive layer and to the dissolution in the bulk phase of nickel ions that have a positive influence on the sulfate-reducing bacteria metabolism.
This phenomenon may enhance the biocorrosion process.
Significance and Impact of the Study: A better understanding of the interactions between metallic surfaces such as stainless steel and bacteria commonly implied in the corrosion phenomena which is primordial to fight biocorrosion.Programme Praxis XXI; University of Santiago de
Compostela
Ewald methods for polarizable surfaces with application to hydroxylation and hydrogen bonding on the (012) and (001) surfaces of alpha-Fe2O3
We present a clear and rigorous derivation of the Ewald-like method for
calculation of the electrostatic energy of the systems infinitely periodic in
two-dimensions and of finite size in the third dimension (slabs) which is
significantly faster than existing methods. Molecular dynamics simulations
using the transferable/polarizable model by Rustad et al. were applied to study
the surface relaxation of the nonhydroxylated, hydroxylated, and solvated
surfaces of alpha-Fe2O3 (hematite). We find that our nonhydroxylated structures
and energies are in good agreement with previous LDA calculations on
alpha-alumina by Manassidis et al. [Surf. Sci. Lett. 285, L517, 1993]. Using
the results of molecular dynamics simulations of solvated interfaces, we define
end-member hydroxylated-hydrated states for the surfaces which are used in
energy minimization calculations. We find that hydration has a small effect on
the surface structure, but that hydroxylation has a significant effect. Our
calculations, both for gas-phase and solution-phase adsorption, predict a
greater amount of hydroxylation for the (012) surface than for the (001)
surface. Our simulations also indicate the presence of four-fold coordinated
iron ions on the (001) surface.Comment: 23 pages, REVTeX (LaTeX), 8 figures not included, e-mail to
[email protected], paper accepted in Surface Scienc
On the structure and evolution of a polar crown prominence/filament system
Polar crown prominences are made of chromospheric plasma partially circling
the Suns poles between 60 and 70 degree latitude. We aim to diagnose the 3D
dynamics of a polar crown prominence using high cadence EUV images from the
Solar Dynamics Observatory (SDO)/AIA at 304 and 171A and the Ahead spacecraft
of the Solar Terrestrial Relations Observatory (STEREO-A)/EUVI at 195A. Using
time series across specific structures we compare flows across the disk in 195A
with the prominence dynamics seen on the limb. The densest prominence material
forms vertical columns which are separated by many tens of Mm and connected by
dynamic bridges of plasma that are clearly visible in 304/171A two-color
images. We also observe intermittent but repetitious flows with velocity 15
km/s in the prominence that appear to be associated with EUV bright points on
the solar disk. The boundary between the prominence and the overlying cavity
appears as a sharp edge. We discuss the structure of the coronal cavity seen
both above and around the prominence. SDO/HMI and GONG magnetograms are used to
infer the underlying magnetic topology. The evolution and structure of the
prominence with respect to the magnetic field seems to agree with the filament
linkage model.Comment: 24 pages, 14 figures, Accepted for publication in Solar Physics
Journal, Movies can be found at http://www2.mps.mpg.de/data/outgoing/panesar
Exposure to maternal cafeteria diets during the suckling period has greater effects on fat deposition and Sterol regulatory element binding protein-1c (SREBP-1c) gene expression in rodent offspring compared to exposure before birth
Background: While the adverse metabolic effects of exposure to obesogenic diets during both the prenatal and early postnatal period are well established, the relative impact of exposure during these separate developmental windows remains unclear. Objective: This study aimed to assess the relative contribution of exposure to a maternal cafeteria diet during pregnancy and lactation on body weight, fat mass and expression of lipogenic and adipokine genes in the offspring. Methods: Wistar rats were fed either a control chow (Control, n=14) or obesogenic cafeteria diet (CAF, n=12) during pregnancy and lactation. Pups were cross-fostered to another dam in either the same or different dietary group within 24 h of birth. Body weight, body fat mass and expression of lipogenic and adipokine genes in subcutaneous and visceral adipose tissues were determined in offspring at weaning and 3 weeks post-weaning. Results: Offspring suckled by CAF dams had a lower body weight (
Parity-Violating Interaction Effects I: the Longitudinal Asymmetry in pp Elastic Scattering
The proton-proton parity-violating longitudinal asymmetry is calculated in
the lab-energy range 0--350 MeV, using a number of different, latest-generation
strong-interaction potentials--Argonne V18, Bonn-2000, and Nijmegen-I--in
combination with a weak-interaction potential consisting of rho- and
omega-meson exchanges--the model known as DDH. The complete scattering problem
in the presence of parity-conserving, including Coulomb, and parity-violating
potentials is solved in both configuration- and momentum-space. The predicted
parity-violating asymmetries are found to be only weakly dependent upon the
input strong-interaction potential adopted in the calculation. Values for the
rho- and omega-meson weak coupling constants and
are determined by reproducing the measured asymmetries at 13.6 MeV, 45 MeV, and
221 MeV.Comment: 24 pages, 8 figures, submitted to Physical Review
Observations of Coronal Mass Ejections with the Coronal Multichannel Polarimeter
The Coronal Multichannel Polarimeter (CoMP) measures not only the
polarization of coronal emission, but also the full radiance profiles of
coronal emission lines. For the first time, CoMP observations provide
high-cadence image sequences of the coronal line intensity, Doppler shift and
line width simultaneously in a large field of view. By studying the Doppler
shift and line width we may explore more of the physical processes of CME
initiation and propagation. Here we identify a list of CMEs observed by CoMP
and present the first results of these observations. Our preliminary analysis
shows that CMEs are usually associated with greatly increased Doppler shift and
enhanced line width. These new observations provide not only valuable
information to constrain CME models and probe various processes during the
initial propagation of CMEs in the low corona, but also offer a possible
cost-effective and low-risk means of space weather monitoring.Comment: 6 figures. Will appear in the special issue of Coronal Magnetism,
Sol. Phy
Effect of a maternal cafeteria diet on the fatty acid composition of milk and offspring red blood cells
Abstract not availableM.A. Vithayathil, J.R. Gugusheff, R.A. Gibson, Z.Y. Ong, B.S. Muhlhausle
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