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 $h^{pp}_\rho$ and $h^{pp}_\omega$ 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