Yield components, harvest index and leaf area efficiency of a sample of a wild population and a domesticated variant of the common bean Phaseolus vulgaris

The objective of this work was to evaluate the differences in distribution of photoassimilates between a sample of a wild population and a domesticated variant of common bean, by comparing the yield components, harvest index, leaf area efficiency and seed filling rate, when grown under greenhouse conditions. Significant positive correlations were observed in the wild common bean for seed yield and seed number per plant and seed number per pod. In contrast, in the domesticated variant there was a positive correlation between seed number and pod number per plant, stem dry weight and number of nodes. Seed size in the domesticated variant was associated positively with yield. The biomass per plant accumulated in stems, leaves and pod walls was statistically similar between the wild and the domesticated variant, but a different distribution of assimilates caused a difference in the size and number of these structures. However, total biomass per plant was higher in the domesticated variant due to high seed biomass. The greater efficiency of seed production of the domesticated bean was associated with a longer life span of the leaves, a higher harvest index and reduced competition between vegetative and reproductive structures. These results support the hypothesis that domestication increased the efficiency in partitioning of photoassimilates toward seeds in the common bean

Lesser magnitudes of lower extremity variability during terminal swing characterizes walking patterns in children with autism

© 2020 Elsevier Ltd Background: Anecdotally, children with Autism Spectrum Disorder have highly variable lower extremity walking patterns, yet, this has not been sufficiently quantified. As such, the purpose of this study was to examine walking pattern variability by way of lower extremity coordination and spatio-temporal characteristics in children with autism compared with individuals with typical development during over-ground walking. Methods: Bilateral continuous relative phase variability was computed for the thigh-leg, leg-foot, and thigh-foot segment couples for 11 children with autism and 9 children with typical development at each gait sub-phase. Furthermore, left and right stride lengths and stride width were computed and compared. The Model Statistic was utilized to test for statistical differences in variability between each child with autism to an aggregate group with typical development. Effect sizes were computed to determine the meaningfulness between responses for children with autism and typical development. Coefficient of variation and effect sizes were computed for stride lengths and stride width. Findings: Analysis revealed that children with autism exhibited differences in variability in each gait sub-phase. Notably, all but two children with autism exhibited lesser variability in all segment couples during terminal swing. Differences in stride lengths were relatively minimal, however, greater coefficient of variation magnitudes in stride width were observed in children with autism. Interpretation: This finding reveals that children with autism may have limited or a preferred movement strategy when preparing the foot for ground contact. The findings from this study suggest variability may be an identifiable characteristic during movement in children with autism

Endothelial Cell Response to Chemical, Biological, and Physical Cues in Bioactive Hydrogels

The highly tunable biological, chemical, and physical properties of bioactive hydrogels enable their use in an array of tissue engineering and drug delivery applications. Systematic modulation of these properties can be used to elucidate key cell–material interactions to improve therapeutic effects. For example, the rate and extent of endothelialization are critical to the long-term success of many blood-contacting devices. To this end, we have developed a bioactive hydrogel that could be used as coating on cardiovascular devices to enhance endothelial cell (EC) adhesion and migration. The current work investigates the relative impact of hydrogel variables on key endothelialization processes. The bioactive hydrogel is based on poly(ethylene glycol) (PEG) and a streptococcal collagen-like (Scl2-2) protein that has been modified with integrin α(1)β(1) and α(2)β(1) binding sites. The use of PEG hydrogels allows for incorporation of specific bioactive cues and independent manipulation of scaffold properties. The selective integrin binding of Scl2-2 was compared to more traditional collagen-modified PEG hydrogels to determine the effect of integrin binding on cell behavior. Protein functionalization density, protein concentration, and substrate modulus were independently tuned with both Scl2-2 and collagen to determine the effect of each variable on EC adhesion, spreading, and migration. The findings here demonstrate that increasing substrate modulus, decreasing functionalization density, and increasing protein concentration can be utilized to increase EC adhesion and migration. Additionally, PEG-Scl2-2 hydrogels had higher migration speeds and proliferation over 1 week compared with PEG-collagen gels, demonstrating that selective integrin binding can be used to enhance cell–material interactions. Overall, these studies contribute to the understanding of the effects of matrix cues on EC interactions and demonstrate the strong potential of PEG-Scl2-2 hydrogels to promote endothelialization of blood-contacting devices