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.

Effects of pH management during deep hypothermic bypass on cerebral oxygenation: alpha-stat versus pH-stat

Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study examined cortical blood flow (CBF), cerebral oxygenation, and brain oxygen consumption in relation to deep hypothermic CPB with alpha-stat or pH-stat management. Methods: Twenty-two pigs were cooled with alpha-stat or pH-stat during CPB to 15 °C esophageal temperature. CBF and cerebral oxygenation were measured continuously with a laser flowmeter and near-infrared spectroscopy, respectively. Brain oxygen consumption was measured with standard laboratory techniques. Results: During CPB cooling, CBF was significantly decreased, about 52.2%±6.3% (P<0.01 vs 92.6%±6.5% of pH-stat) at 15 °C in alpha-stat, whereas there were no significant changes in CBF in pH-stat. While cooling down, brain oxygen extraction (OER) progressively decreased, about 9.5%±0.9% and 10.9%±1.5% at 15 °C in alpha-stat and pH-stat, respectively. At 31 °C the decreased value in pH-stat was lower than in alpha-stat (29.9%±2.7% vs 22.5%±1.9%; P<0.05). The ratio of CBF/OER were 2.0±0.3 in alpha-stat and pH-stat, respectively; it was kept in constant level in alpha-stat, and significantly increased by 19 °C to 15 °C in pH-stat (4.9±0.9 vs 2.3±0.4; P<0.01). In mild hypothermia, cerebral oxyhemoglobin and oxygen saturation in alpha-stat were greater than that in pH-stat (102.5%±1.4% vs 99.1%±0.7%; P<0.05). In deep hypothermia, brain oxygen saturation in pH-stat was greater than that in alpha-stat (99.2%±1.0% vs 93.8%±1.0%; P<0.01), and deoxyhemoglobin in pH-stat decreased more greatly than that in alpha-stat (28.7%±6.8% vs 54.1%±4.7%; P<0.05). Conclusions: In mild hypothermic CPB, brain tissue oxygen saturation was greater in alpha-stat than in pH-stat. However, cerebral oxygenation and brain tissue oxygen saturation were better in pH-stat than in alpha-stat during profound hypothermia. PH-stat strategy provided much more oxygen to brain tissue before deep hypothermic circulatory arrest

Phase Transformations During Solidification of a Laser-Beam-Welded TiAl Alloy—An In Situ Synchrotron Study

An in situ highly time-resolved, high-energy X-ray diffraction investigation was carried out toobserve the phase transformations of a TiAl alloy during laser beam welding. The diffractionpatterns are recorded every 0.1 seconds by a fast area two-dimensional detector and plottedaccording to time, yielding the solidification pathway, the solid phase volume fraction, and thelattice parameter variation of different phases during the solidification and cooling process.Moreover, it is the first study that can demonstrate that the a phase without any Burgersorientation relationship, the so-called non-Burgers a, precipitates appear earlier than theBurgers a. The non-Burgers a grains are found to nucleate on the primary borides

The Current State of Women Print Journalists: An Analysis of the Status and Careers of Females in Newspapers Sports Departments

The purpose of this study was to provide an analysis of the current state of women journalists within the sports departments at newspapers across the United States. This investigation involved a determination of their demographic make-up, job status within the sports department, rationale for entering the field, and advice for younger women preparing to follow in their footsteps. The findings suggest that although the large majority of women have faced discrimination in the sport media, they believe improvements have been made towards equity. The majority of respondents noted that they were happy with the assignments they had been given. Subjects did, however, feel that they were assigned to cover females more than their male counterparts, and some responses regarding dissatisfaction with their positions was also noted. Copyright Springer Science + Business Media, Inc. 2005media, sport, female, journalist, reporters,