Resistance of plants to species of Colletotrichum

Imperial Users onl

Environmental Effects on Yield and Agronomic Traits of Common Bean (Phaseolus vulgaris L.)

Common bean (Phaseolus vulgaris L.) demand is increasing with an alarming rate around the world, especially in Latin America, Africa, and Asia. Therefore, increase bean yield per hectare is the best way to meet the world demand rather than expansion of area under cultivation. The objectives of this experiment were to determine the genotypic variations for green bean and dry seed yield and magnitude of genotype x environment interaction effects on yield and yield components of common bean. Thirteen genotypes were planted during the 1992, 1994, and 1995 growing seasons. Genotypes were evaluated for green pod and seed yield and yield components at R7 and R9 growth stages. Years differed significantly for all recorded parameters at both R7 and R9 stages. Genotypes and genotype x year interaction were also differed significantly for most measured parameters at both stages. The genotype Eagle showed the highest green pod yield, while Branco and Blue Ridge ranked second and third, respectively when averaged over the three years. Number of pods plant-1, hundred pod weight and pod length were positively and significantly correlated with green pod yield. Number of pods plant-1 showed the highest correlation (r = 0.61**) with green pod yield. All the recorded parameters were positively significantly correlated with dry seed yield. Plant height was negatively correlated with seed size, number of seeds plant-1 and seed weight plant-1. Number of pods plant-1 was positively correlated (r = 0.51**) and seed size exhibited highest correlation value (r = 0 .48**) with seed yield. Seed size and number of pods plant -1 can be effectively used for indirect selection of green pod yield and dry seed yield of common bean

Permeation studies of Niacinamide and its effect on human skin

 Background: Niacinamide (NIA) is one of the most commonly used cosmetic ingredients. It belongs to the vitamin-B3 family and has extensive dermatological therapeutic benefits. NIA has been proven to be a useful skincare product in serving as anti-acne agent, preventing skin hyperpigmentation, removal of wrinkles from the face etc.  Aim: To investigate permeability patterns of NIA, its effect on electrical impedance of the skin membrane and the role it plays in maintaining the hydration of stratum corneum (SC). For this, permeation, chromatography, sorption isotherm and X-ray studies were performed. Results: NIA permeation was observed to correlate with pH and it permeated more when delivered in PBS at pH 7.4 as compared to its permeation in citrate buffer at pH 5. Moreover, skin resistance also increased by Ca. 47% in relation to NIA permeation at pH-5 while it decreased by an average of 45% at pH 7.4. In addition, vapor sorption analysis showed that NIA increased the hydration of SC at 95%RH as compared to buffer controls. This was also supported by X-ray data where NIA treated SC samples were shown to have larger interchain spacing in their keratin filaments in comparison to SC in buffer controls. This increase is usually associated with an increase in the water content of SC and thus NIA might have similar beneficial effects as water and can even be more advantageous as it doesn’t evaporate in dehydrated states unlike water. Moreover, artificial skin model has also been tested in parallel, and it was significantly more permeable to NIA than the human skin. Hence some modifications are necessary before it can be used to replace human/porcine skin. Conclusion: The study showed that pH influences NIA permeation and resistance of skin membrane. Additionally, NIA play beneficial roles by increasing water content of SC at high relative humidity (RH%)

Permeation studies of Niacinamide and its effect on human skin

 Background: Niacinamide (NIA) is one of the most commonly used cosmetic ingredients. It belongs to the vitamin-B3 family and has extensive dermatological therapeutic benefits. NIA has been proven to be a useful skincare product in serving as anti-acne agent, preventing skin hyperpigmentation, removal of wrinkles from the face etc.  Aim: To investigate permeability patterns of NIA, its effect on electrical impedance of the skin membrane and the role it plays in maintaining the hydration of stratum corneum (SC). For this, permeation, chromatography, sorption isotherm and X-ray studies were performed. Results: NIA permeation was observed to correlate with pH and it permeated more when delivered in PBS at pH 7.4 as compared to its permeation in citrate buffer at pH 5. Moreover, skin resistance also increased by Ca. 47% in relation to NIA permeation at pH-5 while it decreased by an average of 45% at pH 7.4. In addition, vapor sorption analysis showed that NIA increased the hydration of SC at 95%RH as compared to buffer controls. This was also supported by X-ray data where NIA treated SC samples were shown to have larger interchain spacing in their keratin filaments in comparison to SC in buffer controls. This increase is usually associated with an increase in the water content of SC and thus NIA might have similar beneficial effects as water and can even be more advantageous as it doesn’t evaporate in dehydrated states unlike water. Moreover, artificial skin model has also been tested in parallel, and it was significantly more permeable to NIA than the human skin. Hence some modifications are necessary before it can be used to replace human/porcine skin. Conclusion: The study showed that pH influences NIA permeation and resistance of skin membrane. Additionally, NIA play beneficial roles by increasing water content of SC at high relative humidity (RH%)

Numerical and constitutive modelling of monotonic and cyclic loading in variably saturated soils

A fully coupled, effective stress based elasto-plastic model is presented for a rigorous analysis of flow and deformation in variably saturated porous media subjected to monotonic and cyclic loading. The governing equations are derived based on the effective stress concept, equations of equilibrium, and conservation equations of mass and momentum using a systematic macroscopic approach. Both elastic and elasto-plastic constitutive equations are developed. All model coefficients are identified in terms of measurable parameters. The governing equations presented are general in nature, embodying all previously presented formulations in the field. A unified bounding surface plasticity model is developed to describe the stress-strain behaviour of variably saturated soils subjected to monotonic and cyclic loading. The model is formulated incrementally within the critical state framework using the effective stress approach. The model takes into account the effects of both plastic volumetric strain and matric suction on the hardening of the bounding surface. Cyclic behaviour is captured through a new mapping rule in which the point of stress reversal is taken as the centre of projection. The effect of particle crushing at high stresses is considered through a three-segmented critical state and isotropic compression lines. A non-associative flow rule is employed to generalise application of the model to all soils. Solution to the governing equations is obtained numerically using the finite element approach, with the finite difference method employed for the time integration of the rate equations. The elasto-plastic constitutive equations are integrated explicitly using Eulers forward and the modified Euler integration schemes. Yield surface correction schemes are adopted to improve accuracy of the solution. Essential elements of the proposed model are validated by comparing numerical predictions with experimental data from the literature for fully and partially saturated soils subjected to monotonic and cyclic loadings in drained, undrained, isotropic and deviatoric conditions. The results demonstrate capability of the coupled model to predict essential characteristics of variably saturated soils subjected to monotonic and cyclic loadings in a unified manner