Inhibition of HPI axis response to stress in gilthead sea bream (Sparus aurata) with physiological plasma levels of cortisol     

J. Rotllant  R.J. Arends  J.M. Mancera  G. Flik  S.E. Wendelaar Bonga  L. Tort 《Fish physiology and biochemistry》2000,23(1):13-22

This study investigates the effect of corticosteroid (cortisol) administration on the stress response of the gilthead sea bream Sparus aurata subjected to a 48 h confinement. The effect of (in-vitro and in-vivo ) cortisol administration on the in-vitro ACTH sensitivity of the interrenal tissue; the plasma levels and tissue concentration of cortisol; and the plasma levels of ACTH, -MSH, -endorphin and glucose were determined. Confinement caused a transient and concomitant increase in plasma cortisol and ACTH levels. However, in cortisol-fed fish the plasma ACTH levels were lower, indicating a suppresion of the ACTH release from the corticotropes by cortisol. In contrast to the activation of the corticotropes, the levels of plasma melanotrope derived peptides were not affected. In spite of the fact that interrenal cells of cortisol-fed gilthead sea bream released less cortisol than controls, the interrenal sensitivity to ACTH was not affected by in-vivo and in-vitro cortisol administration. This suggests that the interrenal sensitivity to ACTH in stressed (confinement) sea bream is probably not regulated by -MSH, N-ac--END, or by cortisol. Thus, in gilthead sea bream the interrenal sensitivity to ACTH could be regulated at the hypothalamus and/or pituitary and communicated via circulating ACTH levels.  相似文献   

Extranuclear Histones in Teleost Gills: An Evolutionary Study     

F. M. A. H. Schuurmans Stekhoven  S. E. Wendelaar Bonga  G. Flik 《Fish physiology and biochemistry》2004,30(3-4):201-211

Extranuclear histones and histone fragments (13–15 kDa) in gill microsomes of a phylogenetic series of teleostean fishes (tilapia, trout, carp, eel and elephant fish) were studied. Histones H2A and H2B are the first occurring of these antimicrobial agents. Halfway the evolution of teleosts (carp, trout) H3 fragments emerge, which disappear in later stages of development and are replaced by truncated H1 (tilapia). The hypothesis is forwarded that variation in composition of extranuclear histones is caused by changes in specificity of histone transporters.  相似文献   

AFLP analysis of genetic diversity in leafy kale (<Emphasis Type="Italic">Brassica oleracea</Emphasis> L. convar. <Emphasis Type="Italic">acephala</Emphasis> (DC.) Alef.) landraces,cultivars and wild populations in Europe     

Stina Christensen  Roland von Bothmer  Gert Poulsen  Lorenzo Maggioni  Marianne Phillip  Bente Anni Andersen  Rikke Bagger Jørgensen 《Genetic Resources and Crop Evolution》2011,58(5):657-666

AFLP markers were used to characterize diversity and asses the genetic structure among 17 accessions of kale landraces, cultivars and wild populations from Europe. The range of average gene diversity in accessions was 0.11–0.27. Several landraces showed higher levels of diversity than the wild populations and one cultivar had the lowest diversity measures. The landraces that were most genetically diverse were from areas where kales are known to be extensively grown, suggesting in situ conservation in these areas as a supplement to storage of seeds in gene banks. An analysis of molecular variance (AMOVA) showed that 62% of the total variation was found within accessions. For most accessions, genetic distance was not related to geographic distance. Similarities among accessions were probably not caused by recent gene flow since they were widely separated geographically; more likely the relationship among them is due to seed dispersal through human interactions. Our results indicate that a kale population found in a natural habitat in Denmark was probably not truly wild but most likely an escape from a cultivated Danish kale that had subsequently become naturalized.  相似文献   

High alcohol consumption in Germany: results of the German National Health Interview and Examination Survey 1998     

Burger M  Mensink GB 《Public health nutrition》2004,7(7):879-884

OBJECTIVE: To analyse the alcohol consumption behaviour of the German adult population, with a focus on the characteristics of persons drinking more than the tolerable upper alcohol intake level (TUAL) of 10-12 g day(-1) for healthy adult women and 20-24 g day(-1) for healthy adult men. DESIGN AND SETTING: For the German National Health Interview and Examination Survey 1998, a representative sample of free-living adults was drawn. A total of 7124 participants were interviewed comprehensively about their sociodemographic background, lifestyle and eating habits including alcohol consumption. SUBJECTS: A sub-sample of 4030 women and men, 18-79 years old, who were involved in the integrated German Nutrition Survey. RESULTS: About 16% of women and 31% of men had mean alcohol consumption above the TUAL. Among other factors, the inclination to exceed the TUAL was related to middle-age, high socio-economic status, smoking and use of soft drugs. Among both women and men, a high proportion of persons drinking above the TUAL was observed among those consuming low amounts of soft drinks, fruit, poultry, milk products, bread and cake/biscuits. Women preferred to drink wine, whereas men preferred to drink beer. CONCLUSIONS: Many Germans have an alcohol consumption level above the TUAL and thus are supposed to be at increased risk for alcohol-associated diseases.  相似文献   

Evaluation of Breeding Value and Selection of Bull Dams in the Danish Dairy Breeds: II. Model Calculations of the Effect of Bias on the Efficiency of Selection     

Gert Aamand Pedersen  Poul H. Petersen  Lars Gjøl Christensen 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(1):32-35

Abstract

Alternative selection strategies in the bull dam path were investigated to reduce the magnitude of bias. The study's objective was to examine the effect of alternative strategies under the assumption of particular biases. Bias in the evaluation of bull dam estimated breeding values (EBVs) causes an estimated reduction of 32% in their genetic superiority, compared with the theoretical potential. Biased evaluations caused selection of too many bull dams from later lactations. Two alternative strategies were developed to account for existing bias. Results suggested that the influence of bias could be reduced. The estimated improvement in selection response was 11–13% higher than current practice. Problems with biased EBVs in conventional breeding schemes are discussed and a method to counteract bias from future breeding schemes is presented.  相似文献   

Human impact on sediment dynamics — quantification and timing     

Gert Verstraeten  Andreas Lang  Peter Houben 《CATENA》2009

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The cow as guru     

Prosman G 《Tijdschrift voor diergeneeskunde》2012,137(2):128-129

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Modelling soil carbon sequestration of intensively monitored forest plots in Europe by three different approaches     

Janet P. Mol Dijkstra  Gert Jan Reinds  Hans Kros  Björn Berg  Wim de Vries 《Forest Ecology and Management》2009

Information on soil carbon sequestration and its interaction with nitrogen availability is rather limited, since soil processes account for the most significant unknowns in the C and N cycles. In this paper we compare three completely different approaches to calculate carbon sequestration in forest soils. The first approach is the limit-value concept, in which the soil carbon accumulation is estimated by multiplying the annual litter fall with the recalcitrant fraction of the decomposing plant litter, which depends on the nitrogen and calcium content in the litter. The second approach is the N-balance method, where carbon sequestration is calculated from the nitrogen retention in the soil multiplied with the present soil C/N ratio in organic layer and mineral topsoil. The third approach is the dynamic SMART2 model in combination with an empirical approach to assess litter fall inputs. The comparison is done by first validating the methods at three chronosequences with measured C pools, two in Denmark and one in Sweden, and then application on 192 intensive monitoring plots located in the Northern and Western part of Europe. Considering all three chronosequences, the N-balance method was generally most in accordance with the C pool measurements, although the SMART2 model was also quite consistent with the measurements at two chronosequences. The limit-value approach generally overestimated the soil carbon sequestration. At the intensive monitoring plots, the limit-value concept calculated the highest carbon sequestration, ranging from 160 to 978 kg ha⁻¹ year⁻¹, followed by the N-balance method which ranged from 0 to 535 kg ha⁻¹ year⁻¹. With SMART2 we calculated the lowest carbon sequestration from −30 to 254 kg ha⁻¹ year⁻¹. All the three approaches found lower carbon sequestration at a latitude from 60 to 70° compared to latitudes from 40 to 50 and from 50 to 60. Considering the validation of the three approaches, the range in results from both the N-balance method and SMART2 model seems most appropriate.  相似文献   

Variation in Pathogenicity Among South African Isolates of Phytophthora cinnamomi     

Linde  Celeste  Kemp  Gert H.J.  Wingfield  Michael J. 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(3):231-239

Phytophthora cinnamomi isolates from South Africa were evaluated for differences in growth rate in vitro and levels of pathogenicity towards Eucalyptus smithii in the field. Inoculations were conducted in the field in summer and winter in two subsequent years at two locations in South Africa using 59 P. cinnamomi isolates. The isolates differed significantly in growth rate in vitro, as well as in levels of pathogenicity to E. smithii in the field. Growth rate in vitro was significantly influenced by interactions with culture age, geographic origin and genetic background as determined using isozymes. Levels of pathogenicity in the field were influenced by season of inoculation and average minimum temperatures at trial sites. The host from which P. cinnamomi isolates were originally obtained did not significantly affect levels of pathogenicity in the field. Culture age had a significant negative effect on growth rate in vitro and pathogenicity in the field. Significant differences in levels of pathogenicity could be found for different multilocus isozyme genotypes. Geographic origin and mating type of P. cinnamomi isolates had no significant effect on levels of pathogenicity in the field. A positive correlation was found between growth rate in vitro and levels of pathogenicity in the field. Levels of variation for pathogenicity within A1 mating type isolates were significantly lower than for A2 mating type isolates. Results of this study provide valuable information on selection of P. cinnamomi isolates for future resistance/tolerance screening assays of Eucalyptus germplasm in South Africa.  相似文献   

Genetic diversity in Nordic horseradish,Armoracia rusticana,as revealed by AFLP markers     

Katarina Wedelsbäck Bladh  Erland Liljeroth  Gert Poulsen  Flemming Yndgaard  Agnese Kolodinska Brantestam 《Genetic Resources and Crop Evolution》2014,61(2):383-394

176 horseradish accessions from the Nordic countries Denmark, Finland, Norway and Sweden were analysed to estimate the level of genetic diversity and to propose conservation strategies for this cultivated plant. Most of the accessions were collected in old gardens of the Nordic countries but selections from European countries and Danish breeding lines were also included in the study. Since horseradish is mainly vegetative propagated the genetic diversity has been assumed to be small. However, using the AFLP method with three primer combinations we revealed a significant genetic diversity among Nordic horseradish. The analysis yielded 65 polymorphic bands and we found an overall diversity index of 0.5 (Shannon–Weaver). The highest diversity was found among the Finnish accessions followed by the Danish accessions. An overall AMOVA analysis indicated that 90 % of the variation could be explained by among accession variation. The AFLP data assigned the different accessions into groups that corresponded with their country of origin. A closer relationship was observed between the Swedish, Danish and some of the Norwegian accessions while the Finnish accessions separated more clearly from the other three countries. A possible explanation for the diversity is that horseradish probably has been introduced to the Nordic countries at many occasions during a long period of time.  相似文献