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.

Extending Disjunctive Logic Programming by T-norms

. This paper proposes a new knowledge representation language, called QDLP, which extends DLP to deal with uncertain values. A certainty degree interval (a subinterval of [0; 1]) is assigned to each (quantitative) rule. Triangular norms (T -norms) are employed to define calculi for propagating uncertainty information from the premises to the conclusion of a quantitative rule. Negation is considered and the concept of stable model is extended to QDLP. Different T -norms induce different semantics for one given quantitative program. In this sense, QDLP is parameterized and each choice of a T -norm induces a different QDLP language. Each T -norm is eligible for events with determinate relationships (e.g., independence, exclusiveness) between them. Since there are infinitely many T -norms, it turns out that there is a family of infinitely many QDLP languages. This family is carefully studied and the set of QDLP languages which generalize traditional DLP is precisely singled out. Finally, ..

Moclobemide in Social Phobia: A Controlled Dose-Response Trial

Although the monoamine oxidase inhibitor phenelzine has proven efficacious in social phobia, the risk of hypertensive crises has reduced its acceptability. The reversible monoamine oxidase inhibitor moclobemide has less potential for such reactions, but; its efficacy in this disorder remains unproven. A double-blind, placebo-controlled study was undertaken to assess the efficacy and safety of fixed doses of moclobemide. After a 1-week placebo run-in, subjects with social phobia were randomly assigned to placebo or one of five doses (75 mg, 150 mg, 300 mg, 600 mg, or 900 mg daily) of moclobemide for 12 weeks. Although a trend toward greater efficacy of higher doses of moclobemide was observed at 8 weeks, no differences in response to various doses of the drug and placebo were observed at 12 weeks. At 12 weeks, 35% of subjects on 900 mg of moclobemide and 33% of those on placebo were at least much improved. Moclobemide was well tolerated, insomnia being the only dose-related adverse event observed with the drug. In this dose-response trial, moclobemide did not demonstrate efficacy at; 12 weeks. Some other controlled studies have found moclobemide and brofaromine, another reversible monoamine oxidase inhibitor, efficacious in social phobia. Possible reasons for inconsistent findings are discussed