Organogenesis in internode explants of grapevines

Organogenesis was studied in cultured internodes of grapevine cultivars, hybrids and species. Adventitious root formation occurred with a wide range of media and genotypes. Adventitious buds were formed in explanrts grown in ag1tated liquid culture with NITscH medium supplemented with benzyladenine (1 μM) and 2,4-D (5 μM} or a mixture of 2,4-D and ß-naphthoxyacetic acid (5 μM). Bud formation occurred only in cultures derived from seedlings of Muscadinia rotundifolia, Gloryvine (Vitis vinifera L. x Vitis rupestris ScHEELE) and V. vinifera x Gloryvine, i.e. (Grenache x Cabernet Sauvignon) x Gloryvine and (Sumoll x Cabernet Sauvignon) x Gloryvine. Cuttings from mature vines of V. vinifera cultivars, or from clonal Gloryvine, gave explants which failed to produce buds. Results are discussed in relation to effects of composition of media, origin of explant, maturity of the mother plant and genotype.Organogenese bei Internodienexplaotaten von RebenBei Kalluskulturen aus Internodien verschiedener Rebsorten, -kreuzungen und -arten wurde die Organogenese untersucht. Adventivwurzeln bildeten sich auf zahlreichen Nährmedien und bei vielen Genotypen. Adventivknospen entstanden an Explantaten in Schüttelkulturen auf einem flüssigen Medium nach NITSCH mit einem Zusatz von Benzyladenin (1 μM) und 2,4-D (5 μM) oder einem Gemisch von 2,4-D und ß-Naphthyloxyessigsäure (5 μM). Knospen bildeten sich nur in Kulturen aus Sämlingen von Muscadinia rotundifolia, Gloryvine (Vitis vinifera L. x Vitis rupestris SCHEELE) sowie V. vinifera x Gloryvine, nämlich (Grenache x Cabernet Sauvignon) x Gloryvine und (Sumoll x Cabernet Sauvignon) x Gloryvine. Aus ausgereiftem Holz von V. -vinifera-Sorten oder einem Gloryvine-Klon hergestellte Stecklinge ergaben Explantate, die keine Knospenbildung zeigten. Die Ergebnisse werden im Hinblick auf die Zusammensetzung der Nährmedien, den Ursprung des Explantats, den Reifezustand der Mutterpflanze und den Genotyp diskutiert

Somatic embryo formation by cultured ovules of Cabernet Sauvignon grape: Effects of fertilization and of the male gameticide toluidine blue

Maximum numbers of pollen tubes were found in styles of plants growing at 27 °C (day) and 22 °C (night). Fertilization generally occurred by 24 h after anthesis. Treatment of both isolated pollen and inflorescences of intact vines with toluidine blue (10-100mg l-1) reduced pollen germination and tube growth. Pollen tubes which penetrated the styles of toluidine blue-treated flowers appeared to be abnormal. Somatic embryos were produced with equal frequency by nucellus tissue from cultured ovules from both normally-fertilized and toluidine blue-treated flowers. There was degeneration of embryosacs in all cultured ovules. The grape appears to be unresponsive to toluidine blue as an inducer of haploid parthenogenesis

Co-creating solutions to local mobility and transport challenges for the enhancement of health and wellbeing in an area of socioeconomic disadvantage

Introduction: The paper describes and examines a novel methodology to co-define transport and mobility challenges and co-create solutions with residents of a socioeconomically disadvantaged area within Oxford in the UK. The co-creation methodology is examined in relation to the extent of participation, inclusivity, transparency, interactivity, scale, sustainability/continuity, replicability, potential for co-benefits. Methods: A Citizen Mobility Community was established with local residents at the core, and including representatives from the local authority, and other stakeholders. The paper describes the main elements of the co-creation process applied to identify mobility challenges, identify solutions, endorse the mobility solutions, and develop the solutions into practical action. Setting: The setting was the Eastern Arc of Oxford, the most socioeconomically deprived area in Oxford. Results: A sequence of co-creation activities helped identify and understand the transport challenges in Barton in the Eastern Arc of Oxford. Challenges included the high cost of public transport, traffic congestion, particularly during morning peak times, and the lack of cross-connectivity and direct public transport routes to desirable locations including affordable supermarkets, train stations, workplaces, health services such as hospitals and other neighbourhoods. The co-creation methodology led to the development of three pilot interventions to address these challenges, namely face-to-face transport app training, a transport to supermarkets shuttle service, and an information campaign about concessionary bus passes. Analysis of the co-creation methodology found that the process achieved its aims of empowering citizens in decision making about addressing locally experienced transport challenges, and building social capital. Conclusions: The co-creation enables communities in areas of socioeconomic disadvantage to identify their transport challenges, and to co-develop and co-design practical solutions. Co-creation to address local transport needs builds community empowerment, creates social capital and may contribute, through plausible causal pathways, to improved health and wellbeing in an area of socioeconomic disadvantage

Investigation of prediction methods for the loads and stresses of Apollo type spacecraft parachutes. Volume 2: Stresses

For abstract, see N74-19673

Profile scaling in decay of nanostructures

The flattening of a crystal cone below its roughening transition is studied by means of a step flow model. Numerical and analytical analyses show that the height profile, h(r,t), obeys the scaling scenario dh/dr = F(r t^{-1/4}). The scaling function is flat at radii r<R(t) \sim t^{1/4}. We find a one parameter family of solutions for the scaling function, and propose a selection criterion for the unique solution the system reaches.Comment: 4 pages, RevTex, 3 eps figure

Improvement of dairy production to satisfy the growing consumer demand in sub-Saharan Africa. A conceptual framework for research

This document is based on the deliberations and outputs of two ILCA in-house workshops held in 1992, and of numerous individual contributions by ILCA scientists. This work has similarities with the ILCA project on smallholder market-oriented dairying. Factors influencing development of market-oriented smallholder dairying in SSA, and factors affecting farm productivity in dairying are listed. The objectives and methods of the four phases, viz, typification of dairy system, characterization of a specific dairy system, seeking ways to enhance the development of specific dairy systems and cross-site synthesis are described

On well-posedness, stability, and bifurcation for the axisymmetric surface diffusion flow

In this article, we study the axisymmetric surface diffusion flow (ASD), a fourth-order geometric evolution law. In particular, we prove that ASD generates a real analytic semiflow in the space of (2 + \alpha)-little-H\"older regular surfaces of revolution embedded in R^3 and satisfying periodic boundary conditions. We also give conditions for global existence of solutions and prove that solutions are real analytic in time and space. Further, we investigate the geometric properties of solutions to ASD. Utilizing a connection to axisymmetric surfaces with constant mean curvature, we characterize the equilibria of ASD. Then, focusing on the family of cylinders, we establish results regarding stability, instability and bifurcation behavior, with the radius acting as a bifurcation parameter for the problem.Comment: 37 pages, 6 figures, To Appear in SIAM J. Math. Ana

Decay of one dimensional surface modulations

The relaxation process of one dimensional surface modulations is re-examined. Surface evolution is described in terms of a standard step flow model. Numerical evidence that the surface slope, D(x,t), obeys the scaling ansatz D(x,t)=alpha(t)F(x) is provided. We use the scaling ansatz to transform the discrete step model into a continuum model for surface dynamics. The model consists of differential equations for the functions alpha(t) and F(x). The solutions of these equations agree with simulation results of the discrete step model. We identify two types of possible scaling solutions. Solutions of the first type have facets at the extremum points, while in solutions of the second type the facets are replaced by cusps. Interactions between steps of opposite signs determine whether a system is of the first or second type. Finally, we relate our model to an actual experiment and find good agreement between a measured AFM snapshot and a solution of our continuum model.Comment: 18 pages, 6 figures in 9 eps file

The profile of a decaying crystalline cone

The decay of a crystalline cone below the roughening transition is studied. We consider local mass transport through surface diffusion, focusing on the two cases of diffusion limited and attachment-detachment limited step kinetics. In both cases, we describe the decay kinetics in terms of step flow models. Numerical simulations of the models indicate that in the attachment-detachment limited case the system undergoes a step bunching instability if the repulsive interactions between steps are weak. Such an instability does not occur in the diffusion limited case. In stable cases the height profile, h(r,t), is flat at radii r<R(t)\sim t^{1/4}. Outside this flat region the height profile obeys the scaling scenario \partial h/\partial r = {\cal F}(r t^{-1/4}). A scaling ansatz for the time-dependent profile of the cone yields analytical values for the scaling exponents and a differential equation for the scaling function. In the long time limit this equation provides an exact description of the discrete step dynamics. It admits a family of solutions and the mechanism responsible for the selection of a unique scaling function is discussed in detail. Finally we generalize the model and consider permeable steps by allowing direct adatom hops between neighboring terraces. We argue that step permeability does not change the scaling behavior of the system, and its only effect is a renormalization of some of the parameters.Comment: 25 pages, 18 postscript figure