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排序方式: 共有626条查询结果,搜索用时 62 毫秒
31.
Kurt A.Zuelke 《中国家禽》2007,29(20):30-31
美国农业部目前在依阿华州艾姆斯已完成了其动物卫生研究、诊断及动物产品检验设施的全面的、现代化的重建,共投入4.6亿美元,成为有史以来的美国农业部最大的建设项目.…… 相似文献
32.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(16):513-525
Ohne Zusammenfassung 相似文献
33.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(15):488-497
Ohne Zusammenfassung 相似文献
34.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(2):33-50
Ohne Zusammenfassung 相似文献
35.
Kurt Mantel 《Forstwissenschaftliches Centralblatt》1937,59(19):616-625
Ohne Zusammenfassung 相似文献
36.
Michael Engelbrecht Nielsen Kurt Buchmann 《Journal of the World Aquaculture Society》2003,34(1):11-17
A new product called oralized fish serum concentrate (OFSC) was evaluated for a possible effect against various bacterial pathogens in rainbow trout. The OFSC produced from immune trout sera was found to contain fully functional antibodies and complement component C3. The antibodies detected in the serum concentrate were specific to Vibrio anguillarum (O1 and O2) and Aeromonas salmonicida , which had been used for vaccination of the fish prior to serum collection. The functionality of the specific antibodies in OFSC was not reduced after 6 wk storage at -20 C, 5 C, and 20 C. The serum was mixed with commercial trout feed and used for feeding rainbow trout fry (first feed period). After oral delivery of OFSC to rainbow trout for 1 mo, samples of gut content and gut tissue contained functional antibodies. In gutted fish no functional antibodies were found. This suggests that antibodies from OFSC are unable to be transferred across the gut wall in a functional state. Oral administration of OFSC did not increase survival of rainbow trout in an immersion challenge with Vibrio anguillarum . 相似文献
37.
Two-year-old estern white pine (Pinus strobus L.) seedlings were measured for Root Growth Potential (RGP) in a hydroponic system over two years in both a greenhouse and an environmentally controlled growthroom. Analyses of variance showed no significant differences (alpha = 0.05) between testing environments for either year. This study demonstrates the validity of using greenhouse RGP testing for 2+0 eastern white pine. 相似文献
38.
Zusammenfassung Das Aussetzen von 24 Serien von Palmen in Kübeln in einem Krankheitsgebiet für eine beschränkte Zeit, 7 Sätze von 15–20 Palmen für einen Monat, 3 Sätze für zwei Monate und 14 Sätze für drei Monate, diente zur Ermittlung der Inkubationszeit für die Tödliche Vergilbung der Kokospalme. In den meisten Fällen, die zur Ansteckung im Krankheitsgebiet führten, lag die geschätzte Inkubationszeit zwischen 3 und 6 Monaten; nach dem aufgestellten Histogramm betrug die durchschnittliche Inkubationszeit 150–160 Tage. Die lange Expositionszeit bei der größeren Zahl der Sätze erlaubt keine genaue Festlegung der Zeitspanne. Nach Entfernen von Käfigen in einem zweiten Versuch, die als Schutz gegen Infektionen dienten, traten erstmals Symptome an Palmen nach 6 (1 Palme) und 7 (2 Palmen) Monaten auf. Unter Berücksichtigung, daß der Ausbruch einer Krankheit Schwankungen unterworfen ist und auß erdem wesentlich vom Infektionszeitpunkt abhängt, fügen sich diese Daten gut in die für die Inkubationszeit angenommene Zeitspanne ein.Bodenorganismen (Nematoden) scheiden als Überträger der Tödlichen Vergilbung aus, da die Palmen in Kübeln keinen Bodenkontakt hatten. Die Palmen in den Käfigen dagegen konnten, soweit sie in den Boden gepflanzt waren, mit ihren Wurzeln unter den Käfigrand vordringen und wären dadurch der Infektion zugänglich gewesen.Da nur in den Sätzen, die den Infektionsbedingungen eines Krankheitsgebietes zwischen den Monaten Februar und August ausgesetzt waren, einzelne Palmen in den Gruppen erkrankten, dürfte in dieser Zeitspanne der Ü berträger besonders aktiv oder in der übrigen Zeit des Jahres relativ selten sein, anders wäre die Häufung der Infektionen in diesen Monaten nicht zu erklären.
F.A.O.- Expert in Kingston, Jamaica; jetzt: Biologiche Bundesanstalt für Land- und Forwirschaft, Berlin-Dahlem.
F.A.O.- Associate-Expert in Kingston (Coconut Industry Board.
Biologische Bundesanstalt für Land- und Forstwirstchaft, 1 Berlin 33 Dahlem, Königin-Luise-Straße 19. 相似文献
Summary A transfer experiment using 17 sets of coconut palms, planted in drums and transferred bimonthly or three-monthly from a healthy into a diseased area (2 or 3 months exposure time) and 7 sets exposed for only a month, provided us with good information about the incubation period of Lethal Yellowing in a palm. The most probable incubation period ranges between 3 and 6 months; according to the dates on the histogram the mean incubation period appeared to be 150–160 days. The long exposure time used for most of the sets does not allow a more accurate assessment of this time interval.In a second experiment, groups of coconut palms which had been protected by cages for at least a year against infections were exposed to the natural infection conditions by removal of the cages. The first case of disease was recognized 6 months after cage removal, 2 additional cases a month later. Taking into consideration that the development of symptoms varies within a time interval depending upon the date of infection, growing conditions etc, this observation agress with the inferred incubation period gained in the transfer experiment.Soil organisms (nematodes o. a.) can be excluded as transmitters of the Lethal Yellowing pathogen. The palms used in the transfer experiment which later on showed symptoms were planted in drums; the roots having no connection with the soil in the field. The soil for filling the drums was collected in a healthy area. The roots of caged palms which were planted directly into the soil could penetrate under the cage border into the unprotected part of the plot which contained a lot of naturally diseased palms scattered across the field.Only sets of palms which were partly or fully exposed to the infection conditions of a diseased area during February to August developed a number of cases of Lethal Yellowing. The occurrence of infection during this period indicates this to be a time of particular vector activity.
F.A.O.- Expert in Kingston, Jamaica; jetzt: Biologiche Bundesanstalt für Land- und Forwirschaft, Berlin-Dahlem.
F.A.O.- Associate-Expert in Kingston (Coconut Industry Board.
Biologische Bundesanstalt für Land- und Forstwirstchaft, 1 Berlin 33 Dahlem, Königin-Luise-Straße 19. 相似文献
39.
Sanni Raiskila Kurt Fagerstedt Tapio Laakso Pekka Saranpää Mia Löija Leena Paajanen Riitta Mahlberg Anne-Christine Ritschkoff 《Wood Science and Technology》2006,40(8):697-707
It is known that active peroxidase isozymes exist in mature wood of Norway spruce (Picea abies L. Karst.) and that they remain active for years and are found even in the heartwood (in Scots pine), where all cellular activity has ceased. This peroxidase activity was utilised in the impregnation of wood blocks with a natural monolignol, coniferyl alcohol and hydrogen peroxide. The hypothesis was that the internal wood peroxidases would oxidise the added monolignol and bind it stably into the cell wall matrix, which could hinder fungal decay. Since coniferyl alcohol is not very soluble in water, the impregnation was done under vacuum with an acetone–water solution containing 10% coniferyl alcohol and 0.4 mM H2O2 at room temperature (ca. 0.02 g of coniferyl alcohol was added to 1 g of wood). After impregnation, dimers of coniferyl alcohol and free coniferyl alcohol were found in acetone extracts with GC–MS analysis. Penetration of coniferyl alcohol and non-extractable reaction products were studied from the wood blocks with FTIR PAS technique. The wood samples treated were also subjected to a fungal decay test with Coriolus versicolor. This treatment hindered fungal decay in a 60-day experiment and led to a dry weight loss of 8.8% in comparison with 19.9% in the control. The reactions of coniferyl alcohol and H2O2 in the presence of peroxidases are discussed as well as the use of monolignols to increase wood decay resistance. 相似文献
40.
Kurt Becker 《Journal of pest science》1965,38(12):186-187
Zusammenfassung Nach einer Mitteilung aus dem Ende des 18. Jahrhunderts sollen sich in Blüte stehende Pflanzen vonVerbascum thapsus als Mittel zur Vertreibung vonMus musculus undRattus norvegicus eignen. Eine Nachprüfung dieser Empfehlung mitV. thapsus, lychnitis undthapsiforme anMus verlief negativ.
Summary At the end of the eighteenth centuryGoeze reports about the action ofVerbascum thapsus as a repellent againstMus musculus andRattus norvegicus. A revision of this information withV. thapsus, lychnitis andthapsiforme andMus musculus as test animals does not confirm his findings.相似文献