Influences of day and night temperatures on flowering of Fragaria x ananassa Duch., cvs. Korona and Elsanta,at different photoperiods

The effects of photoperiod (12, 13, 14, 15 or 16 h), day temperature (12, 15, 18, 24 or 27 °C) and night temperature (6, 9 or 12 °C) and their interactions on flower and inflorescence emergence were investigated by exposing 4 week old runner plants of strawberry cvs. Korona and Elsanta during a period of 3 weeks. A daily photoperiod of 12 or 13 h resulted in the highest number of plants with emerged flowers. A photoperiod of 14 h or more strongly reduced this number, while no flowers emerged at a photoperiod of 16 h. Plants exposed to photoperiods of 12 or 13 h flowered earlier and had longer flower trusses. A day temperature of 18 °C and/or a night temperature of 12 °C were optimal for plants to emerge flowers and resulted in the shortest time to flowering. A night temperature of 6 °C strongly reduced the number of plants that emerged flowers, especially when combined with lower day temperatures. Photoperiod and temperature had no effect on the number of inflorescences, all flowering plants produced on average one inflorescence. The number of flowers on the inflorescence increased with decreasing day temperature and when photoperiod was raised from 12 to 15 h. In general, ‘Korona’ was more sensitive to photoperiod and temperature as ‘Elsanta’, and had a lower optimal day temperature for flower emergence. Results of this experiment may be used to produce high quality plant material or to define optimal conditions when combining flower induction and fruit production.     

微生物饲料添加剂对肉仔鸡大肠杆菌抑制及血液生化指标的影响

将216只商品代肉用公雏随机分成4组,对照组分别为空白组和150mg/kg金霉素组,处理组分别使鸡只饮服2种不同的微生物饲料添加剂,定期检测直肠中大肠杆菌数量,研究微生物制剂在体内与大肠杆菌的生物颉颃作用,在肉仔鸡前期和中期测定血液生化指标,研究微生物饲料添加剂对肉仔鸡免疫功能和血液指标的影响。结果显示,2种液态微生物饲料添加剂可促进肉仔鸡生长,使42日龄体质量分别比对照组高4.71%和2.62%,可提高肉仔鸡的存活率(P<0.05),降低直肠中大肠杆菌的数量(P<0.05),降低血液中甘油三酯和低密度脂蛋白,升高高密度脂蛋白。     

Synthesis of a DDT analogue with crown ether substituents

Based on considerations of membrane activity, a DDT analogue containing crown ether moieties has been conceived and prepared. The preparation of the compound represents a novel route for obtaining crown ether derivatives.     

Listeriosis in sheep. Listeria monocytogenes excretion and immunological state in sheep in flocks with clinical listeriosis.

The excretion of Listeria monocytogenes (Lm) in the faeces and milk, and humoral immunity against Lm, were examined in a sheep flock with outbreaks of listeric encephalitis and in a flock with outbreaks of listeric abortion. The encephalitis flock consisted of 86 ewes and 20 hoggs, the abortion flock of 45 ewes and 3 hoggs, all of them pregnant. Faecal excretion rate in the encephalitis flock varied from about 25 % in the first part of the indoor season to nearly zero 1 month later, to about 30 % 1 month before lambing and about 15 % at lambing. About 15 % of the animals also excreted Lm in the milk. Lm 4 was the dominating serotype.In the abortion flock about 2/3 of the animals excreted Lm in the faeces and 1/3 in the milk at lambing. All the isolates belonged to serotype 1, which also was isolated from grass silage and strawbedding samples.In the encephalitis flock ewes with ≥ 3 foetuses had a higher excretion rate than the remainder, while no such differences were found in the abortion flock.Antibody titres against Lm in sera and whey in the encephalitis flock were of the same order as in the healthy flock described in an earlier publication (Grønstøl 1979), except that the highest titres were found in the hoggs. Serum titres from the abortion flock after lambing were significantly higher than in the encephalitis flock, while whey titres were of the same order.Treatment with 2-mercapto-ethanol reduced the titres substantially in sera from the abortion flock, indicating that the antibodies belonged to the IgM-fraction, while only a slight reduction was seen after similar treatment of the whey.     

Einige Bemerkungen zur Frage der Anwendung der Gaschromatographie in der Weinindustrie

Zusammenfassung Zur Beurteilung der Güte von Nahrungsmitteln sind die organoleptischen, mit mathematisch-statistischen Methoden verbesserten Analysenverfahren noch nicht durch gaschromatographische ersetzt. Die Ursachen hierfür werden erläutert. Interessante Gebiete für die Anwendung der Gaschromatographie sind die qualitative und quantitative Identifizierung der Aromastoffe, relative Vergleichsuntersuchungen von Aromastoffen, Nachweis von Verunreinigungen und Verfälschungen, ferner Serienuntersuchungen in verschiedenen Industriezweigen.

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Summary In the evaluation of the quality of foods, the procedures of organoleptic analyses, improved nowadays by mathematical and statistical methods, have not yet been replaced by methods based on gas chromatography. Interesting fields for the application of gas chromatographic analyses are the qualitative and quantitative determination of aromas, identification of contaminations and adulterations, and serial tests in different branches of industry.

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Résumé Pour juger la qualité des aliments, les procédés d'analyse organoleptique, améliorés aujourd'hui par des méthodes mathématiques et statistiques, ne sont pas encore remplacés par des méthodes de chromatographie en phase gazeuse. L'auteur en explique les raisons. Les domaines intéressants pour l'application des analyses par chromatographie en phase gazeuse sont l'identification qualitative et quantitative des arômes, les études comparatives des arômes, l'identification de pollutions et de falsifications, puis des essais de série dans différentes branches industrielles.