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1.
1. This paper addresses the possibility of using a monthly model for the genetic evaluation of laying hens, based on the definition of a test day model with fixed regression as used in dairy cattle, in which monthly records were treated as repeated measurements of the same trait. 2. Production records of 6450 hens, daughters of 180 sires and 1335 dams were analysed using an animal model with restricted maximum likelihood (REML). The traits considered were individual monthly egg production and cumulative egg production in 11 months. Four different models were fitted to various combinations of monthly and cumulative records. The covariates were derived from the regression of Ali and Schaeffer (1987). 3. Spearman rank correlations were computed to compare breeding values from different models. Two types of correlations were computed: between individual breeding values and between sire breeding values based on subsets of full-sib records. 4. The results indicated that a monthly model with nested covariates produced higher heritability and permanent environmental variance than the models with non-nested or without covariates. The estimates of heritability obtained from monthly model were lower than the estimates from the cumulative model. The monthly model resulted in higher correlations of sire breeding values between two subsets of full-sib records than those from cumulative models. 5. In conclusion, the monthly model with nested covariates appears to be better than the model with non-nested covariates or without covariate. Although the heritability estimates obtained from the monthly model were lower, the monthly model with nested covariates could be better than the cumulative model for genetic evaluation of laying hens in the 1st cycle of laying period when using either full or part records. The use of information from odd months of production could be of interest for the evaluation of full records.  相似文献   
2.
Estrogens of human and animal origin that reach the aquatic environment may enter human or animal organism and act as endocrine disruptors.To investigate the persistency of estrogens in laboratory experiments, estrone respectively 17beta-estradiol were added to stream water sampled from river Spree in Berlin. The concentration of estrone and 17beta-estradiol was quantified using enzyme-immuno-assay. The estrone concentration decreased to less than 5 % of the starting concentration at storage temperature of 5 degrees C within 56 days and at storage temperature of 20 degrees C within 14 days. If the estrone were added to autoclaved stream water, no biodegradation was observed. Biodegradation was enhanced when activated sludge was added. Escherichia coli, Pseudomonas fluorenscens and Aeromonas hydrophila in monoculture did not degrade estrone in autoclaved stream water.The concentrations of 17beta-estradiol and estrone decreased similarly.The logistic function proved to be suitable to describe the course of time for the decrease of concentration.  相似文献   
3.
Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pig breeds. Since some of them are able to infect human cells, they might represent a risk for xenotransplantation using pig cells or organs. However, the expression and biological role of PERVs in healthy pigs as well as in porcine tumours is largely unknown. Since we and others have recently shown overexpression of a human endogenous retrovirus, HERV-K, in human melanomas, we studied the expression of PERVs in melanomas of selectively bred Munich miniature swine (MMS) Troll. This breeding herd of MMS Troll is characterised by a high prevalence of melanomas, which histologically resemble various types of cutaneous melanomas in humans. Several genetic factors have been defined when studying inheritance of melanomas and melanocytic nevi in MMS Troll. Here we show that the polytropic PERV-A and PERV-B as well as the ecotropic PERV-C are present in the genome of all melanoma bearing MMS Troll investigated. Most interestingly, in the spleen, but not in other organs, recombinant PERV-A/C proviruses were found. PERV expression was found elevated in melanomas when compared to normal skin and viral proteins were expressed in melanomas and pulmonary metastasis-derived melanoma cell cultures. During passaging of these cells in vitro the expression of PERV mRNA and protein increased and virus particles were released as shown by RT activity in the supernatant and by electron microscopy. Genomic RNA of PERV-A, -B and -C were found in pelleted virus particles. Although PERV expression was elevated in melanomas and pulmonary metastasis-derived cell cultures, the function of the virus in tumour development is still unclear.  相似文献   
4.
Interleukin-8 plays a critical role in inflammatory processes. Hence generation of molecules with anti-IL-8 activity is likely to be important for successful feeding and for survival of the ticks. Anti-IL-8 activity was studied in saliva of three ixodid tick species--Dermacentor reticulatus (Fabricius, 1794), Rhipicephalus appendiculatus Neumann, 1901, and Amblyomma variegatum (Fabricius, 1794). The greatest activity was shown in saliva prepared from D. reticulatus. The activity was attributed to tick salivary gland molecules that bind to IL-8, preventing binding of the chemokine to its specific receptor, rather than to occupation of the IL-8 cell receptor by the tick molecules. The distribution of anti-IL-8 activity in fast protein liquid chromatography (FPLC) fractions of salivary gland extracts (SGE) derived from adult female D. reticulatus, R. appendiculatus and A. variegatum was compared directly by both ELISA and receptor-binding inhibition assays. The correspondence in results with fractions of SGE from ELISA is consistent with detection of tick molecules that inhibit IL-8 binding to its receptor. As IL-8 is an important chemoattractant and activator of neutrophils, the presence of an anti-IL-8 activity in tick saliva indicates that neutrophils play an important role in the host response to parasitism by ticks.  相似文献   
5.
To study adherence of Actinobacillus pleuropneumoniae to porcine lower respiratory epithelium, a cell culture model was developed using primary cultures of porcine lung epithelial cells (LEC). Adherence assays were performed and results were compared with data obtained with swine kidney cells (SK6). A. pleuropneumoniae efficiently adhered to LEC with up to 62 bacteria per cell after 2h of incubation. Reference strain of serotype 3 (R3) adhered better to LEC than reference strains of serotypes 1 (R1), 7 (R7) and 8 (R8). Overall the adherence to LEC was more rapid and up to 30-fold more efficient than adherence to SK6 cells. In search for the mechanism involved in the adherence event, we tested the effect of LPS which has previously been demonstrated to cause adherence of the pathogen to upper respiratory epithelium. Adherence assays with LPS transposon mutants demonstrated unaltered (mutant with modification in core/lipid A moiety) or even three-fold more adherence (mutants lacking O antigen) compared to the parent micro-organisms. Purified LPS of strains R1, R3, R7 and R8 did not inhibit adherence of R8 to LEC either, suggesting that LPS and particularly the O-antigen are not essential for adherence of A. pleuropneumoniae to LEC. The efficient, LPS-independent adherence of A. pleuropneumoniae to LEC cells indicates that A. pleuropneumoniae may carry different, cell type-specific adhesins and that primary cultures of lower respiratory epithelium are valuable infection models in studying A. pleuropneumoniae pathogenesis.  相似文献   
6.
1. We investigated the use of monthly production records for genetic evaluation of laying hens, derived from a test day model with random regression in dairy cattle and compared it with other models. 2. Records of 6450 hens, daughters of 180 sires and 1335 dams, were analysed using a model with restricted maximum likelihood (REML): traits considered were monthly and cumulative egg production. Five models were studied: (1) random regression with covariates derived from the regression of Ali and Schaeffer (Canadian Journal of Animal Science, 67: 637-644, 1987) (RRMAS), (2) random regression with covariates derived from quartic polynomial (RRMP4), (3) fixed regression with covariates derived from Ali and Schaeffer (FRM), (4) multiple trait (MTM) and (5) cumulative (CM). 3. The models were compared on the basis of Spearman rank correlations of individual breeding values and sire breeding values estimated from subsets of full-sib split data. The hens (about 10% per generation) which ranked highest on their estimated breeding values from different models were compared phenotypically with their full records. 4. The estimates of heritability resulting from RRMP4 were biased upward from the estimates obtained from MTM, so this model was discarded. The heritabilities for monthly productions from RRMAS and MTM showed a similar pattern. They were high for the 1st month of production, decreased to their lowest value at about month 5 of production and increased again to the end of lay. 5. Spearman rank correlations between animal breeding values estimated by monthly models (RRMAS, FRM and MTM) were high, between 0.91 and 0.98, whereas those between estimates of monthly models and CM were lower, from 0.85 to 0.87. The correlations estimated either from intermittent months of measurements (odd vs even months) or full records were generally high, from 0.93 to 0.99. Information from odd months of production could be sufficient for cost-efficient recording schemes. The RRMAS generally had the highest correlation of sire breeding values between subsets of full-sib records, followed by MTM, RM and CM. Monthly models selected hens with higher productivity than the cumulative model. 6. In conclusion, genetic evaluation based on monthly production may be better than using cumulative production and RRMAS appeared to be the best among the models tested here.  相似文献   
7.
The relationship between the physicochemical properties (molar volume, partition coefficient, and dissociation constant) of slow-acting systemic postemergence xenobiotics and their uptake and translocation to the sites of action was investigated using the nonlinear, dynamic simulation model ERMESSE. When the pKa was held constant at 4.0, the model enables the prediction of the uptake of a systemic xenobiotic as a function of its partition coefficient and molar volume. The model also considered the effects of the physicochemical properties of a systemic xenobiotic on its long-distance translocation within the vascular tissues. For instance, when the log Kow and pKa were held constant at 1.5 and 6.0, respectively, the model predicted a higher translocation rate (55%) for molecules with a small (e.g., MV = 100 cm3 mol−1) as opposed to a large (e.g., MV = 300 cm3 mol−1, 33%) molar volume. In addition, the theoretical predictions from the ERMESSE model showed that any xenobiotic with a molar volume not exceeding 300 cm3 mol−1 could provide an uptake ?50% and a translocation rate ?25% when its log Kow is between −0.5 and 2.5 and its pKa is between 0.0 and 8.0.  相似文献   
8.
Zusammenfassung In der vorliegenden Arbeit werden Laborversuche zur Markierung von Nonnenraupen und Nonnenfaltern mit den Seltenen Erden Europium und Dysprosium behandelt, sowie Freilanduntersuchungen zum Studium der Ausbreitung mit Europium gekennzeichneter Nonnenfalter. Imagines, die mit Mengen von 1/Exemplar im Raupenstadium besprüht worden waren, erwiesen sich, ebenso wie im Vorjahr in derselben Weise behandelte Kiefernspinner, als deutlich markiert. Zur Kennzeichnung der Falter gelangten im Labor und im Freiland 10 Europium, im Labor auch 10 Dysprosium/Exemplar mittels Besprühung erfolgreich zur Anwendung. Die Ausbreitungsuntersuchungen ergaben einen Überflug markierter Falter auf eine Entfernung von 2 km.
Summary The present paper describes laboratory experiments in marking nun-caterpillars and nun-moths with the rare earths Europium and Dysprosium, as well as field studies on the spread of nun-moths marked with Europium. Nun-moths, sprayed with quantities of 1/individual in the caterpillar stage, proved distinctly marked, and so did pine spinners(Dendrolimus pini) treated the same way past year. Marking of moths succeeded in both laboratory and field by spraying with 10 Europium, in the laboratory also with 10 Dysprosium per individual. Spreading studies revealed marked moths overflying distances of 2 kilometres.

Résumé L'ouvrage présent traite d'essais en laboratoire sur le marquage de chenilles et de papillons de la Nonne(L. monacha) au moyen des terres rares Europium et Dysprosium, ainsi que de recherches au terrain sur l'expansion de papillons de cette espèce marqués d'Europium. Les images de la Nonne, ayant été aspérgées au stade larvaire d'une dose de 1 par individu, se sont avérées distinctement marquées, de même que les Bombyx du Pin traités de la même manière l'année passée. — Le marquage de papillons a été effectué avec succès au laboratoire et au terrain au moyen de 10 d'Europium — au laboratoire aussi de 10 de Dysprosium — par individu, appliqués par aspersion. Les recherches sur l'expansion ont révélé un survol de papillons marqués à une distance de 2 km.


Für weitgehende Unterstützung der entomologischen Untersuchungen sei den Herren Dr. W. Schedl, Förster C. Holzschuh und Förster F. Stradner der forstlichen Bundesversuchsanstalt, der physikalischen Auswertung Herrn Ing. D. Koch, Reaktorzentrum Seibersdorf, herzlich gedankt. Besonderer Dank sei auch der Landesforstinspektion Niederösterreich, der Bezirksforstinspektion Waidhofen/Thaya und der Forstverwaltung von Fischen-Ankern für großzügige Hilfe bei der Durchführung der Freilanduntersuchungen ausgesprochen.  相似文献   
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