Development of a network for the on-farm conservation of crop genetic resources: First results of a pilot project for the re-introduction of old Lactuca varieties to the market

In a pilot project, we examined the chance of maintaining plant genetic resources by commercial utilization of old varieties using Lactuca sativa as a model plant. Nine market gardens in the region of Berlin and Brandenburg cultivated 18 old varieties during four cultivation periods to test field performance. They supplied the products to the market in their customary manner to analyse marketing success. Seven of the market gardens practice organic horticulture. In a complementary field trial at Humboldt-Universität zu Berlin, we established data concerning the field performance of the varieties, analysed dry matter contents, nitrate and phenol concentrations, and observed shelf life for two days under simulated retail conditions (18°C, 80% rel. air humidity). Generally, yield was acceptable for market purposes. However, cultivation in autumn failed because of the cold climate. Biotic and abiotic factors like slugs or hail caused non-specific damages. Specific problems of particular varieties were less important. Based on the results of 2007, the varieties can be put preliminarily into three categories: suitable for on-farm conservation, suitable for home gardens, and varieties with contrasting results depending on the respective market garden.The nitrate concentrations of all varieties were clearly below the EU acceptable limit of 2500 mg/kg fresh weight of lettuce grown in the field. The phenol concentrations varied from 3.3 to 17.2 mg GAE/g dry weight. Generally, the cultivars had a reasonable shelf life of one to two days, however three varieties showed a better storability whereas four other cultivars deteriorated rapidly. Marketing success was good in Berlin City but poor in the countryside of Brandenburg. The regular customers of the market gardens in Berlin who prefer organic food are a promising target group for further stimulation of interest to buy rare crop varieties. The on-farm conservation of old varieties in market gardens requires relatively large quantities of seeds of good quality. However there might arise problems in seed supply as the VERN e.V. was confronted with bottleneck problems. Therefore, we organised a network of interested market gardens who take on maintenance and propagation of individual varieties. The network will be developed in co-operation with the VERN e.V. who will also process the seed as well as organise the exchange of the various varieties within the network. Further, the network will deal with problems concerning maintenance breeding and seed quality

The Sariçiçek Howardite Fall in Turkey: Source Crater of HED Meteorites on Vesta and İmpact Risk of Vestoids

The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Tiisotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 kms-1 from NW, fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antonia impact crater on Vesta was formed on terrain of the same age as given by the 4He retention age of Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was formed ~22 Ma ago

REMOVED: Membrane Capacitive Deionization: An Economical Alternative for Water Desalination?

This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been removed at the request of the Executive Publisher.This article has been removed because it was published without the permission of the author(s)

Étude spectrométrique de complexes à transfert de charge pyridines substituées-brome

On a étudié le spectre d’absorption électronique du brome (transition πg→σu) complexé par une quinzaine de dérivés pyridiniques.La stœcbiométrie 1 : 1 unique des complexes est vérifiée par le contrôle matriciel de BIUEGLEB-LIPTAY, la méthode des variations continues et l’apparition de points isosbestiques dans les spectres expérimentaux.Les constantes de stabilité, déterminées à 25 °C dans deux solvants différents obéissent aux équationslog K(CCl4) = 0,45 pKa —0,31 [1]log K(CH5Cl—CH2Cl) = 0,49 pka — 0,06. [2Des déviations importantes intervenant aussi pour les enthalpies de complexation sont observées pour les bases pyridiniques portant un ou deux substituants en position ortho. La comparaison des relations [1] et [2] montrent que les constantes de stabilité sont nettement plus élevées dans le dichloroéthane (ε = 10,36) que dans le tétrachlorure de carbone (ε = 2,23). L’augmentation de la constante diélectrique du solvant favorise la stabilité de ces complexes du type n — σ pour lesquels le poids de la structure dative est supérieur à 0,30. Par contre les complexes de type π — CT ou π - π, caractérisés par un poids de structure dative plus faible (0,02 à 0,04) sont généralement moins stables lorsque la polarité du solvant augmente. Ce fait est expliqué par des interactions entre les molécules de solvant et les molécules de soluté séparées. Ces forces deviennent plus fortes lorsque la constante diélectrique du solvant augmente et masquent les effets de transfert de charge, qui, suivant la théorie de H. W. HANNA, ont été surestimés pour les complexes faibles à l’état gazeux

Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in (60)Co beams

A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in (60)Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems

Effects of intermittent-direct-electric-current (IDC) on polyphenols and antioxidant activity in radish (Raphanus sativus L.) during growth

In the present study the effects of intermittent-direct-electric-current (IDC; for one hour per day) on phenolic compounds and antioxidant activity in radish (Raphanus sativus L.) was studied. The radish plants were cultivated in rock wool substrate in combination with drip irrigation. Two stainless steel plates were added on the rock wool substrate and acted as electrodes to supply the currents to the plants. Three different IDC treatments (200 mA, 600 mA, and 1000 mA) were applied during growth period and passed horizontally through the nutrient solution as well as through the tissue of the radish plants. After 16 days of growth the radish plants were randomly harvested, divided into three segments (root, tuber, shoot) and were used for the determination of total phenolic content, anthocyanins, and antioxidative activity.This new technology increased the health-promoting phytochemical compounds in radish segments with no sign of damage. In radish tubers total phenol content, anthocyanins, and antioxidant activity increased with increasing IDC. The same was observed for the total phenol content in radish roots. However in contrast, the phenolic compounds of radish shoots remained unaffected by IDC. In conclusion IDC can serve as a general mean to stimulate the synthesis of phenolic compounds and associated antioxidant activity in radish tubers