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21.
An outbreak of leptospirosis in seals (Phoca vitulina) in captivity is described. In a zoo in The Netherlands 5 adult seals died within 12 days. At necropsy all animals showed signs of acute septicaemia, consistent with acute leptospirosis. Serological examination of one animal was positive for antibodies against Leptospira interrogans serovar Icterohaemorrhagiae and the serologically closely related serovar Copenhageni. Polymerase chain reaction was positive in one other animal. 8 nutria (Myocastor coypus) were examined, serologically, through bacteriological culture and PCR. 81,8% (9/11) were serologically positive for Leptospira. The seals and nutria were housed in the same water system. 相似文献
22.
Selenium content and distribution in cow's milk supplemented with two dietary selenium sources 总被引：2，自引：0，他引：2
Muñiz-Naveiro O Domínguez-González R Bermejo-Barrera A Cocho de Juan JA Fraga Bermúdez JM Goris Pereiras A López Santamariña A Martínez Lede I Valledor Puente J Fernández-Couto Gómez L Bermejo-Barrera P 《Journal of agricultural and food chemistry》2005,53(25):9817-9822
The effect of two sources of Se, selenized yeast (Se-Y) and sodium selenite, added to total mixed rations (TMR) fed to cows on Se milk content and distribution in milk components was studied on three farms for 6 weeks. The maximal increase in milk Se was attained with Se-Y supplemented at 0.3 microg g(-1). The effect was immediate, with an increase of 9 microg L(-1) being observed after only 5 days, and remained steady until the last sample at day 40 of Se supplementation. Se distribution in milk components was constant, 53.6, 42.6, and 9.3% in whey, casein, and fat, respectively, and was unaffected by the form of supplementation. The effect of the level of Se-Y supplementation on milk Se was studied on two farms. Increasing dietary Se-Y from 0 to 0.5 microg g(-1) elevated milk Se content from 20 to 39 microg L(-1). Se-enriched cow's milk at different levels can be produced by varying dietary Se supplementation in the form of selenized yeast. 相似文献
23.
M. André Goris 《Plant foods for human nutrition (Dordrecht, Netherlands)》1969,18(4):283-306
In the cultivated carrot, carbohydrate reserves consists of glucose, fructose, saccharose and occasionally small quantities of starch. Pectins, although quite abundant, do not however seem to constitute a reserve material for the plant.The carbohydrate composition of the root varies considerably during its development leading especially to an abrupt change in the respective proportions of saccharose and reducing sugars during what may be called the period of ripening. Thus the level of saccharose doubles while the concentrations of glucose and fructose are reduced by about 40 and 65% respectively. Once ripening is over the carbohydrate reserves accumulate steadily to attain an increase of about 35% in the case of saccharose and 30% in that of reducing sugars.Climatic and ecological factors exert an undeniable influence on the level and the type of carbohydrate reserves, but the intensity of their effect does not exceed that of the variations observed between tuberous roots of the same lot harvested at different times after ripening.Individual variations in the carbohydrate composition of the roots of the same stock observed at a given time may attain 40% of the mean value of total sugars with deviations of up to 100% for saccharose, 30% for glucose and 60% for fructose. Sugar content is not directly related to the weight of the organ.The xylem and the phloem parenchymas of carrot roots differ in their carbohydrate composition which is of the same level when expressed in terms of total sugar per dry weight, but the proportion of saccharose is less in the xylem than in the phloem. This may indicate distinct types of metabolism, the more so as the xylem has a higher water content. In a single parenchyma the distribution of sugars in each xylem or phloem can be very uneven; thus the apex is generally richer in total sugar than the base, though the latter has the highest level of saccharose.The heterogeneity in the distribution of sugars observed in the mass of a tuberous root can therefore be easily explained by the uneven distribution of xylem and phloem parenchymas, whose composition is different and, besides, not uniform over the length of the root.Changes in reserve sugars are produced in carrots stocked during winter. There is usually a drop in reducing sugars, while saccharose remains constant in roots that retain most of their moisture in silos, and increases in roots that undergo partial drying in cellars. In the latter case a condensation of saccharose from reducing sugars can be imagined to compensate for the increase in the osmotic pressure of the cell sap that follows drying.
Zusammenfassung Die Reserven an Kohlenhydraten bestehen in der Karotte aus Glukose, Fruktose, Saccharose und manchmal auch aus kleineren Mengen an Stärke. Die ebenfalls reichlich vorhandenen Pektine, scheinen währenddessen für die Pflanze keine Reservestoffe zu sein.Die Zusammensetzung der verschiedenen Kohlenhydrate, im Laufe der Entwicklung der Wurzel zu einem gegebenen Zeitpunkt Maturation genannt, macht eine plötzliche Veränderung bezüglich des Verhältnisses von Saccharose zu reduziertem Zucker durch. Der Anteil von Saccharose steigt auf das Doppelte, während sich die Konzentration von Glukose und Fruktose um 40 und 65% vermindert. Nach vollendeter Maturation stellt man fest, daß sich die Anhäufung von Kohlenhydrat-Reserven fortsetzt, im Laufe der Zeit kann sich also der Gehalt an Saccharose um 35% vermehren, der an reduzierendem Zucker um ungefähr 30%.Die klimatischen und ökologischen Faktoren üben einen bedeutenden Einfluß auf den Gehalt und die Art der Kohlenhydrat-Reserven aus, ihre Wirkung scheint aber nicht die genetischen Unterschiede der einzelnen Individuen zu übertreffen, die man bei Wurzeln gleicher Ernten zu verschiedenen Terminen nach der Maturation beobachten kann.Die individuellen Veränderungen der Kohlenhydrat-Zusammensetzung der Wurzeln der gleichen Aussaat, die zu einem gegebenen Zeitpunkt geerntet werden, können 40% des mittleren Wertes des Gesamt-Zuckers, mit Unterschieden von 100% an Saccharose, von 30% an Glukose und von 60% an Fruktose erreichen.Der Gehalt an Zucker in den Wurzeln steht in keiner direkten Beziehung zum Organgewicht. Die Parenchyme Xylem und Phloem der Karottenwurzel haben eine verschiedene Kohlenhydrat-Zusammensetzung. Sie besitzen fast den gleichen Gehalt des Gesamt-Zuckers bezogen auf das Trockengewicht, aber das Verhältnis der Saccharose ist bedeutend niedriger im Xylem als im Phloem, worauf gut auf den unterschiedlichen Metabolismus zu schließen ist, zumal das Xylem mehr Wasser als das Phloem enthält. Im gleichen Parenchym erweist sich die Verteilung der Kohlenhydrate als sehr ungleich: die Spitze des Organs ist im allgemeinen viel reicher an Gesamt-Zucker als der obere Teil unter den Blättern, der Anteil an Saccharose ist jedoch in diesem Teil höher. Die ungleichförmige Verteilung des Zuckers in einer Wurzel erklärt sich dann leicht durch die ungleiche Verbreitung von Xylem- und Phloemparenchym, dessen Zusammensetzung verschieden ist und unter anderem für beide variabel in seiner ganzen Größe ist.In den während des Winters gelagerten Karotten vollzieht sich eine Umwandlung der Reserven an Kohlenhydraten. Immer findet ein Absinken des Gehaltes an reduzierendem Zucker statt. Während der Gehalt an Saccharose konstant bleibt, wenn die Wurzeln in feucht gehaltenen Silos gelagert werden, findet eine Erhöhung statt, wenn die Karotten bei Kellerlagerung teilweise austrocknen. Wir können uns denken, daß es sich in diesem letzten Fall um eine Kondensation von Saccharose aus einem Teil des reduzierenden Zuckers handelt, um die infolge Wasserverlust durch Austrocknung bedingte Erhöhung des osmotischen Drucks auszugleichen, der durch die Konzentration des vakuolären Saftes aufrecht erhalten wird.相似文献
24.
Andrea I. Varela Katherina Brokordt Stefanie M.H. Ismar-Rebitz Chris P. Gaskin Nicholas Carlile Terence O'Dwyer Josh Adams Eric A. VanderWerf Guillermo Luna-Jorquera 《水产资源保护:海洋与淡水生态系统》2021,31(2):367-377
- Many seabird breeding colonies have recovered from heavy anthropogenic disturbance after conservation actions. The widely distributed red-tailed tropicbird, Phaethon rubricauda, was used as a model species to assess potential anthropogenic impacts on the genetic diversity of breeding colonies in the Pacific Ocean.
- Cytochrome c oxidase subunit I and control region sequences analyses were conducted across the range of the species in the Pacific Ocean. The study sites were at islands without human-related disturbance (non-impacted islands) and with human-related disturbance (impacted islands). We hypothesized that (i) breeding colonies of the red-tailed tropicbird on impacted islands have lower genetic diversity compared with colonies on non-impacted islands, and (ii) breeding colonies of the red-tailed tropicbird show significant fine and broad-scale genetic structure across the Pacific Ocean. Bayesian skyline analyses were conducted to infer past changes in population sizes.
- Genetic diversity was similar between impacted and non-impacted islands. There was significant broad-scale genetic structure among colonies separated by over 6,000 km, but a lack of significant fine-scale genetic structure within Australasia and Hawai'i, although a significant level of differentiation was found within Chile with ΦST analyses. Skyline analyses showed that effective population sizes remained relatively constant through time, but experienced either a slight decrease or the end of an expansion event through the last 1,000 years. These changes may be related to the arrival of humans on Pacific islands.
- Impacted islands may have received immigrants from other relatively close islands, buffering the loss of genetic diversity. However, it is also possible that colonies have retained ancestral variation or that a large effective population size coupled with a long generation time (13 years) has prevented the loss of genetic diversity in human-impacted islands. Future research using higher-resolution markers is needed to resolve the population genetic structure of the red-tailed tropicbird in an ecological time-scale.
25.
A formal compositional study of the proanthocyanidins of Vitis vinifera L. cv. Carménère was conducted in this work. We first characterized the polymeric proanthocyanidins of Carménère skins, seeds, and wines. In addition, the wine astringency was analyzed and compared with Cabernet Sauvignon. Although Carménère wines had a higher proanthocyanidin concentration and mean degree of polymerization than Cabernet Sauvignon wines, the former wines were perceived as less astringent. The low seed/skin proportion in Carménère wines as compared to other varieties, as evidenced by the reduced number of seeds per berry and the higher amount of epigallocatechin subunits of Carménère wine proanthocyanidins, could explain this apparent paradox. 相似文献