Effect of Population, Collection Year, After-Ripening and Incubation Condition on Seed Germination of \u3cem\u3eStipa bungeana\u3c/em\u3e

Knowledge of the germination behavior of different populations of a species can be useful in the selection of appropriate seed sources for restoration. The aim of this study was to test the effect of seed population, collection year, after-ripening and incubation conditions on seed dormancy and germination of Stipa bungeana, a perennial grass used for revegetation of degraded grasslands on the Loess Plateau, China. Fresh S. bungeana seeds were collected from eight locally-adapted populations in 2015 and 2016. Dormancy and germination characteristics of fresh and 6-month-old dry-stored seeds were determined by incubating them over a range of alternating temperature regimes in light. Effect of water stress on germination was tested for fresh and 6-month-old dry-stored seeds. Seed dormancy and germination of S. bungeana differed with population and collection year. Six months of dry storage broke seed dormancy, broadened the temperature range for germination and increased among-population differences in germination percentage. The rank order of germination was not consistent in all germination tests, and it varied among populations. Thus, studies on comparing seed dormancy and germination among populations must consider year of collection, seed dormancy states and germination test conditions when selecting seeds for grassland restoration and management

The relationship between anxiety and performance: A cognitive-behavioral perspective

ABSTRACT This paper examines the relationship between anxiety and performance from a cognitivebehavioral perspective. Previous research in the field has suggested that the majority of consultations conducted by sport psychologists are related to anxiety. Included is a discussion on the theoretical underpinnings of anxiety and how it relates to performance. Research conducted on the relationship between anxiety and performance is also discussed. A review of the cognitive-behavioral treatments that have been used for anxiety reduction and performance enhancement within the field of athletics is included. Suggestions for future research and practical considerations are listed in the conclusion

On radiative heat transfer in stagnation point flow of MHD Carreau fluid over a stretched surface

This paper investigates the behavior of MHD stagnation point flow of Carreau fluid in the presence of infinite shear rate viscosity. Additionally heat transfer analysis in the existence of non-linear radiation with convective boundary condition is performed. Moreover effects of Joule heating is observed and mathematical analysis is presented in the presence of viscous dissipation. The suitable transformations are employed to alter the leading partial differential equations to a set of ordinary differential equations. The subsequent non-straight common ordinary differential equations are solved numerically by an effective numerical approach specifically Runge-Kutta Fehlberg method alongside shooting technique. It is found that the higher values of Hartmann number M correspond to thickening of the thermal and thinning of momentum boundary layer thickness. The analysis further reveals that the fluid velocity is diminished by increasing the viscosity ratio parameter (β∗) and opposite trend is observed for temperature profile for both hydrodynamic and hydromagnetic flows. In addition the momentum boundary layer thickness is increased with velocity ratio parameter α and opposite is true for thermal boundary layer thickness. Keywords: Magnetohydrodynamic flow, Carreau viscosity model, Stagnation point flow, Heat transfer analysis, Non-linear radiation, Joule heating, Numerical computation

The effect of temperature and water stress on laboratory germination of Eucalyptus globulus Labill. seeds of different sizes

Germination rate and germination capacity of Eucalyptus globulus Labill. increased significantly with increasing temperature (13o to 33 oC) for all seed sizes to an optimum at 28 oC, then decreased. Biggest seeds generally germinated best at all temperatures. Germination was also very sensitive to water potential (0 to $-0.75$ MPa), with no germination occuring at potentials below $-0.25$ MPa.Effet de la température et du stress hydrique sur la germination en laboratoire de graines d'Eucalyptus globulus Labill de différentes tailles. On a étudié l'influence sur la germination des graines d'Eucalyptus globulus Labill de températures constantes comprises entre 13o et 33 oC et de potentiels hydriques compris entre 0 et $-0,75$ MPa. La germination était significativement influencée par la température et la taille des graines. La vitesse et le taux de germination augmentaient avec la température pour atteindre un optimum à 28 oC et ensuite diminuaient. Quand la germination était effectuée en conditions de stress on observait une diminution du taux de germination entre $-0,01$ et $-0,75$ MPa. Plus aucune graine ne germait à $-0,25$ MPa et au-delà

On multiple solutions of non-Newtonian Carreau fluid flow over an inclined shrinking sheet

This paper presents the multiple solutions of a non-Newtonian Carreau fluid flow over a nonlinear inclined shrinking surface in presence of infinite shear rate viscosity. The governing boundary layer equations are derived for the Carreau fluid with infinite shear rate viscosity. The suitable transformations are employed to alter the leading partial differential equations to a set of ordinary differential equations. The consequential non-linear ODEs are solved numerically by an active numerical approach namely Runge–Kutta Fehlberg fourth-fifth order method accompanied by shooting technique. Multiple solutions are presented graphically and results are shown for various physical parameters. It is important to state that the velocity and momentum boundary layer thickness reduce with increasing viscosity ratio parameter in shear thickening fluid while opposite trend is observed for shear thinning fluid. Another important observation is that the wall shear stress is significantly decreased by the viscosity ratio parameter β∗ for the first solution and opposite trend is observed for the second solution. Keywords: Dual solutions, Carreau fluid, Inclined shrinking sheet, Viscosity ratio parameter, Shooting metho

Plant-Derived Transfer DNAs

The transfer of DNA from Agrobacterium to plant cell nuclei is initiated by a cleavage reaction within the 25-bp right border of Ti plasmids. In an effort to develop all-native DNA transformation vectors, 50 putative right border alternatives were identified in both plant expressed sequence tags and genomic DNA. Efficacy tests in a tobacco (Nicotiana tabacum) model system demonstrated that 14 of these elements displayed at least 50% of the activity of conventional Agrobacterium transfer DNA borders. Four of the most effective plant-derived right border alternatives were found to be associated with intron-exon junctions. Additional elements were embedded within introns, exons, untranslated trailers, and intergenic DNA. Based on the identification of a single right border alternative in Arabidopsis and three in rice (Oryza sativa), the occurrence of this motif was estimated at a frequency of at least 0.8×10(−8). Modification of plasmid DNA sequences flanking the alternative borders demonstrated that both upstream and downstream sequences play an important role in initiating DNA transfer. Optimal DNA transfer required the elements to be preceded by pyrimidine residues interspaced by AC-rich trinucleotides. Alteration of this organization lowered transformation frequencies by 46% to 93%. Despite their weaker resemblance with left borders, right border alternatives also functioned effectively in terminating DNA transfer, if both associated with an upstream A[C/T]T[C/G]A[A/T]T[G/T][C/T][G/T][C/G]A[C/T][C/T][A/T] domain and tightly linked cytosine clusters at their junctions with downstream DNA. New insights in border region requirements were used to construct an all-native alfalfa (Medicago sativa) transfer DNA vector that can be used for the production of intragenic plants