Quantification of <Emphasis Type="Italic">Pyrenophora graminea</Emphasis> in barley seed using real-time PCR     

Annemarie Fejer Justesen  Henrik Jørskov Hansen  Hans O. Pinnschmidt 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(2):253-263

A real-time PCR assay was designed to quantify seed-borne infection of Pyrenophora graminea in barley (Hordeum vulgare). Conventional tests such as the freezing blotter method cannot distinguish P. graminea from the closely related P. teres. The seed infection threshold for P. graminea is lower than the one for P. teres and is therefore applied for both species although P. graminea may be absent. This results in unnecessary rejections of seed lots. PCR primers and a TaqMan probe were designed to target a P. graminea-specific DNA sequence. The potential of the real-time PCR assay for quantifying seed-borne infection of P. graminea was investigated by examining seed lots harvested from P. graminea-infected fields. The major part (84%) of the variation in the amount of P. graminea DNA measured by real-time PCR could be attributed to variation between seed lots while only about 8% was due to variation within seed lots. DNA quantities of P. graminea were positively correlated with seed infection incidence detected by the freezing blotter method as well as with the infection incidence of plants examined in the greenhouse. Both correlations were highly significant (P < 0.001) but the DNA quantities accounted only for 59% (R ² = 0.59) and 56% (R ² = 0.56), respectively, of the variation in the results obtained by the two conventional methods. Seed lots of varieties resistant to P. graminea contained considerable amounts of P. graminea DNA but showed no or only few leaf symptoms in the greenhouse test suggesting that the recommended seed infection thresholds could be raised for resistant varieties.  相似文献   

Ecosystem C and N dynamics affected by a modified spring barley trait with increased nitrogen use - a simulation case study     

Henrik Eckersten  Håkan Marstorp  Dennis Collentine  Holger Johnsson  Thomas Kätterer 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2018,68(3):230-242

To what extent might a crop with increased plant N uptake efficiency and/or N demand increase plant biomass and soil carbon storage, decrease N leaching, and reduce the need for N fertilisation? This was assessed for a fertilised sandy loam site in central Sweden cultivated with spring barley for a four year period using a process based crop and soil simulation model (SOILN) calibrated to fit observations of field experiments with non-modified crops. Crop properties were changed in accordance with previous model applications to other crops with higher N uptake and utilisation efficiencies, to resemble potential effects of breeding. For the modified crops a doubling of daily uptake efficiency of soil mineral N and/or increase of radiation use efficiency by 30%, increased plant biomass by 3%–30%, decreased N leaching by 1%–30% and increased soil organic carbon (SOC) content by 1–12?g?C?m^?2 year^?1. The larger changes were mainly due to increased uptake efficiency. Fertilisation of the modified spring barley crop could be reduced while still producing the same plant biomass as the non-modified crop. The plant biomass to N leaching ratio of the modified crops increased. The simulated changes in plant biomass and SOC were sensitive to weather conditions suggesting that in situ experiments would need to cover a large range of weather conditions to evaluate the performance of new crop traits under climatic variability. The study suggests a strong need that field experiments are accompanied with model applications, when exploring the potential of the modified crops under variable conditions.  相似文献   

Conjunctival mucinous adenocarcinoma in an ostrich (Struthio camelus)          下载免费PDF全文

Kathryn L. Perrin  Mads F. Bertelsen  Henrik Bartholin  Carsten Grøndahl  Steffen Heegaard 《Veterinary ophthalmology》2017,20(6):547-550

A 2‐year‐old male ostrich (Struthio camelus) presented with a rapidly growing soft tissue mass protruding from the ventromedial aspect of the right eye (OD). The initial physical examination revealed a soft tissue mass attached to the medial inferior conjunctiva. The mass was excised with cryosurgery, and the conjunctival tissue margins were treated with cryoablation. Histopathological examination diagnosed granulomatous inflammation associated with scattered acid‐fast bacteria. The ostrich recovered uneventfully and appeared healthy until recurrence of a grossly similar mass 2 months later. Gross examination revealed a botryoid mass attached to the inferior palpebral conjunctiva and extending onto the palpebral aspect of the nictitating membrane. Euthanasia was selected, and the histological diagnosis of the second mass was a mixed mucinous adenocarcinoma; however, no acid‐fast bacteria were seen. Granulomatous conjunctival lesions have been previously described in the ostrich, while, to the authors' knowledge, neoplastic conjunctival lesions have not. Neoplasia should be considered as a differential diagnosis for a rapidly recurring, granulomatous conjunctival mass in this species.  相似文献   

Production and markets of modified wood in Russia     

Veronika Kiseleva  Henrik Heräjärvi  Maria Riala  Anne Toppinen 《Wood material science & engineering》2017,12(2):72-81

Understanding the state of market for modified wood as well as the forces that affect its future development will be essential for those seeking to enter the Russian market. Information on modified wood from websites of companies, research and development organisations, woodworking-oriented magazines and forums, and official Russian statistics were explored, and finally verified by personal contacts with experts. A number of modification methods have been either researched, developed or pre-commercialised during the past 15 years, but only few of them have been adopted by users. Mostly, the modification methods have been copied, further developed and commercialised from variations of thermal modification originally introduced in Western Europe. Modified wood products are still considered premium goods among Russian consumers. Political initiatives aim at increasing the share of wood in construction and renovation but also at import minimisation, which reduces the penetration of foreign producers into the markets. There are approximately 20 producers of thermally modified timber (TMT) with an overall annual capacity of 60,000–65,000 m³. The current annual market for TMT is estimated to be approximately €35–40 million. In contrast to the European mainstream end uses of TMT, there is also a market for massive and glued thermally modified logs in Russia.  相似文献   

A simulation study to assess statistical methods for binary repeated measures data     

Elmabrok Masaoud  Henrik Stryhn 《Preventive veterinary medicine》2010,93(2-3):81-97

Binary repeated measures data are commonly encountered in both experimental and observational veterinary studies. Among the wide range of statistical methods and software applicable to such data one major distinction is between marginal and random effects procedures. The objective of the study was to review and assess the performance of marginal and random effects estimation procedures for the analysis of binary repeated measures data. Two simulation studies were carried out, using relatively small, balanced, two-level (time within subjects) datasets. The first study was based on data generated from a marginal model with first order autocorrelation, the second on a random effects model with autocorrelated random effects within subjects. Three versions of the models were considered in which a dichotomous treatment was modelled additively, either between or within subjects, or modelled by a time interaction. Among the studied statistical procedures were: generalized estimating equations (GEE), Marginal Quasi Likelihood, likelihood based on numerical integration, penalized quasi-likelihood, restricted pseudo likelihood and Bayesian Markov Chain Monte Carlo. Results for data generated by the marginal model showed autoregressive GEE to be highly efficient when treatment was within subjects, even with strongly correlated responses. For treatment between subjects, random effects procedures also performed well in some situations; however, a relatively small number of subjects with a short time series proved a challenge for both marginal and random effects procedures. Results for data generated by the random effects model showed bias in estimates from random effects procedures when autocorrelation was present in the data, while the marginal procedures generally gave estimates close to the marginal parameters.  相似文献   

Capacity of model biobeds to retain and degrade mecoprop and isoproturon     

Henriksen VV  Helweg A  Spliid NH  Felding G  Stenvang L 《Pest management science》2003,59(10):1076-1082

Biobeds are used to increase the adsorption and degradation of pesticide spillage on sites used for mixing and loading and for cleaning of sprayers. The adsorption and the rate of degradation of 14C-labelled isoproturon and mecoprop (MCPP) at concentrations from 0.0005 to 25 000 mgkg(-1) were determined in biobed soil. Further leaching of the two herbicides was determined in a model biobed with a surface area of 2 m2. The biobed material showed enhanced ability to adsorb the two herbicides. Kd was 5.2 litre kg(-1) for isoproturon and 1.6 litre kg(-1) for MCPP in biobed material, which is higher than in natural soil. In different experiments with natural soil, Kd ranges from 0.07 to 0.6 litrekg(-1) for MCPP and from 1.5 to 4.6 litre kg(-1) for isoproturon in soils with varying organic carbon content. Degradation of MCPP was rapid at concentrations from 0.0005 to 500 mg kg(-1), delayed at 5000 mg kg(-1), and very slow at 25 000 mg kg(-1). For isoproturon, the relative degradation was most rapid at the lowest concentration and decreasing with increasing concentrations. After 120 days, between 55% and 8% 14C was evolved as 14CO2 at concentrations between 0.0005 and 25 000 mg kg(-1). The rate of evolution of 14CO2 indicated that degradation rates at low concentrations were of first-order and at higher concentrations of zero-order. Leaching of MCPP and isoproturon was determined in a newly established model biobed during a 2-year period. About 13% of applied MCPP and 1.4% of applied isoproturon leached out during the winter following the first autumn application (worst-case scenario). Leaching was completely prevented when the biobed had a well-developed grass cover and was covered during the winter.  相似文献   

Observer agreement on pen level prevalence of clinical signs in finishing pigs     

Petersen HH  Enøe C  Nielsen EO 《Preventive veterinary medicine》2004,64(2-4):147-156

Four observers performed a standard clinical examination of finisher pigs in two commercial finisher herds. In herd 1, 600 finisher pigs in 44 pens were examined. The observers assessed clinical signs of lameness, umbilical hernia and tail bite according to a standardized procedure. The prevalence of the clinical signs was estimated at the pen level. The procedure was repeated after 3 months in another herd, where 730 finisher pigs in 69 pens were examined. The agreement between observer pairs was assessed using prevalence-adjusted bias-adjusted kappa (PABAK) and proportionate-agreement estimates (P_pos and P_neg).

Observer bias was present despite training and standardization of the participating observers. The highest pen level agreement for the observer pairs was found for pens that had one or more pigs with tail bite (PABAK = 0.82–1.00) and umbilical hernia (PABAK = 0.77–1.00). The agreement was fair-to-moderate for identification of pens holding one or more lame pigs (PABAK = 0.27–0.71). In general, the average agreement of observer pairs on absence of clinical signs (P_neg) was higher than for presence (P_pos). The observer bias varied between observer pairs and with the clinical signs.  相似文献   

Susceptibility of different bacterial species isolated from food animals to copper sulphate, zinc chloride and antimicrobial substances used for disinfection     

Aarestrup FM  Hasman H 《Veterinary microbiology》2004,100(1-2):83-89

A total of 569 different bacterial isolates (156 Salmonella, 202 E. coli, 43 S. aureus, 38 S. hyicus, 52 E. faecalis, 78 E. faecium) were tested for susceptibility to copper sulphate, benzalkonium chloride, hydrogen peroxide and chlorhexidine using MIC determinations. A total of 442 isolates were also tested for susceptibility to formaldehyde and 177 isolates for susceptibility to zinc chloride. Enterococcal isolates formed a bimodal distribution of MICs to copper sulphate, whereas the other bacterial species formed one large population. Otherwise the isolates formed one large population of susceptibilities to the different antimicrobial agents. Large variations were observed in the susceptibility of the different bacterial species to the different compounds. Staphylococci were in general very susceptible to all antimicrobial compounds tested. The Salmonella isolates were in general less susceptible to copper sulphate, benzalkonium chloride and chlorhexidine followed by E. coli and the Gram-positive species. The opposite was the case for zinc chloride. All isolates were very susceptible to H(2)O(2) with MICs ranging from 0.002 to 0.016%, and to formaldehyde with MICs at 0.003 and 0.006%. This study showed that Danish bacterial isolates from livestock so far have not or have only to a limited degree developed resistance to antimicrobial compounds commonly used for disinfection. Acquired copper resistance was only found in enterococci. There were large differences in the intrinsic susceptibility of the different bacterial species to these compounds, and Salmonella especially seems intrinsically less susceptible than the other bacterial species, which might have human health implications.  相似文献   

Revised definition of Actinobacillus sensu stricto isolated from animals. A review with special emphasis on diagnosis     

Christensen H  Bisgaard M 《Veterinary microbiology》2004,99(1):13-30

The taxonomy of the members of the genus Actinobacillus associated with animals has been reviewed with focus on classification and identification including molecular based characterization, typing and identification. Out of the 22 species or species like taxa reported as Actinobacillus, 19 are associated with animals. When classified on the basis of 16S rRNA sequence based phylogenetic analysis, DNA-DNA hybridizations and phenotypic analysis, Actinobacillus sensu stricto is restricted to include A. lignieresii, A. pleuropneumoniae, A. equuli subsp. equuli, A. equuli subsp. haemolyticus (taxon 11 of Bisgaard), A. hominis, A. suis, A. ureae, A. arthritidis (taxon 9 of Bisgaard), Actinobacillus genomospecies 1 and 2 and the taxa 8 and 26 of Bisgaard. The remaining 11 species of Actinobacillus are unrelated to A. sensu stricto and should consequently be grouped with other genera or be renamed as new genera depending on new data. Identification of members of Actinobacillus at species level is possible through phenotypic characterization combined with information on host of isolation. PCR tests are available for specific detection of A. pleuropneumoniae. Only A. pleuropneumoniae is presently considered as a primary pathogen. Based on different types of RTX genes it is possible to PCR type A. pleuropneumoniae to serotype level. PCR might also be used for the specific detection of A. equuli subsp. haemolyticus. Epidemiological investigations and surveillance have so far included serotyping, multilocus enzyme electrophoresis (MLEE), ribotyping and restriction fragment length profiling.  相似文献   

Allometric scaling of M-mode cardiac measurements in normal adult dogs   总被引：1，自引：0，他引：1  

Cornell CC  Kittleson MD  Della Torre P  Häggström J  Lombard CW  Pedersen HD  Vollmar A  Wey A 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2004,18(3):311-321

Indices for M-mode measurements in dogs usually have been based on the assumption that a linear relationship exists between these measurements and body weight (BW) or body surface area (BSA). The relationships between the geometry of 3-dimensional objects do not support this assumption. The purposes of this study were to retrospectively examine M-mode data from a large number of dogs of varying sizes and breeds that were examined by a large number of ultrasonographers, to use the allometric equation to determine the appropriate BW exponent required to predict these cardiac dimensions, and to determine normal mean values and prediction intervals for common M-mode variables. Linear regression analyses of data from 494 dogs (2.2-95 kg) revealed a good correlation between M-mode measurements and BW after logarithmic transformation of the data (r2 = .55-.88). Most variables were most closely related to an index of body length, BW(1/3), although the exponent that best predicted diastolic and systolic left ventricular wall thicknesses was closer to 0.25. No variable indexed well to BW or BSA. With these data, appropriate mean values and prediction intervals were calculated for normal dogs, allowing veterinarians to correctly and appropriately index M-mode values. The equations developed from this study appear to be applicable to adult dogs of most breeds.  相似文献