95 research outputs found
Tomato: a crop species amenable to improvement by cellular and molecular methods
Tomato is a crop plant with a relatively small DNA content per haploid genome and a well developed genetics. Plant regeneration from explants and protoplasts is feasable which led to the development of efficient transformation procedures.
In view of the current data, the isolation of useful mutants at the cellular level probably will be of limited value in the genetic improvement of tomato. Protoplast fusion may lead to novel combinations of organelle and nuclear DNA (cybrids), whereas this technique also provides a means of introducing genetic information from alien species into tomato. Important developments have come from molecular approaches. Following the construction of an RFLP map, these RFLP markers can be used in tomato to tag quantitative traits bred in from related species. Both RFLP's and transposons are in the process of being used to clone desired genes for which no gene products are known. Cloned genes can be introduced and potentially improve specific properties of tomato especially those controlled by single genes. Recent results suggest that, in principle, phenotypic mutants can be created for cloned and characterized genes and will prove their value in further improving the cultivated tomato.
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Using a game to engage stakeholders in extreme event attribution science
The impacts of weather and climate-related disasters are increasing, and climate change can exacerbate many disasters. Effectively communicating climate risk and integrating science into policy requires scientists and stakeholders to work together. But dialogue between scientists and policymakers can be challenging given the inherently multidimensional nature of the issues at stake when managing climate risks. Building on the growing use of serious games to create dialogue between stakeholders, we present a new game for policymakers called Climate Attribution Under Loss and Damage: Risking, Observing,co-Negotiating (CAULDRON). CAULDRON aims to communicate understanding of the science attributing extreme events to climate change in a memorable and compelling way, and create space for dialogue around policy decisions addressing changing risks and loss and damage from climate change. We describe the process of developing CAULDRON, and draw on observations of players and their feedback to demonstrate its potential to facilitate the interpretation of probabilistic climate information and the understanding of its relevance to informing policy. Scientists looking to engage with stakeholders can learn valuable lessons in adopting similar innovative approaches. The suitability of games depends on the policy context but, if used appropriately, experiential learning can drive co-produced understanding and meaningful dialogue
Onstage or behind the scenes? Relative learning benefits of simulation role-play and design
In this article, the authors report the results of two experiments that explored hypotheses about the relative learning advantages of role-play and scenario design. The experiments were conducted with similar student populations in Australia and Israel. Using a matched-pairs design, participants were randomly assigned to design and role-play conditions. They worked on their tasks following an hour-long lecture on three negotiation concepts: alternatives, time pressure, and negotiating power. A lecture-only control group was implemented in the Australian experiment. In both experiments, designers, working 'behind the scenes' indicated better concept learning in the short run than their role-play counterparts performing 'onstage', as well as in comparison with the control group. They showed better understanding of the way the concepts are related and retained the learning gains over time. Moreover, the designers were at least as motivated as role-players and controls and, for the Israel participants, showed more motivation. The results, favoring designers, spread widely across the various questions, asked immediately after the experience and 1 week later: 86% of the answers given favored designers in terms of direction; 52% of these were statistically significant. Implications are discussed for explanatory mechanisms, programmatic research, and teaching/training approaches
Direct evidence for hidden one-dimensional Fermi surface of hexagonal
The electronic structure of hexagonal potassium tungsten bronze has been investigated by high-resolution angle-resolved photoemission spectroscopy (ARPES). The experimentally determined band structure resolves the long-standing puzzles concerning the anomalous transport properties in this hexagonal bronze. We find that the ARPES-derived Fermi surface is the consequence of hidden one-dimensional (1D) bands, in good agreement with the calculated Fermi surface. These results indicate that the high-temperature anomaly in the electrical resistivity originates in the possible charge-density-wave formation associated with the hidden 1D Fermi surfaces
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