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201.
Kay?HamerEmail author Astrid?Hadeler Thomas?Muschalla Jürgen?Schr?ter Günter?Timmer 《Journal of Soils and Sediments》2003,3(4):284-291
Goal
Annually, 400.000 m3 harbour sediments are dredged to maintain the water depth in the harbours of Bremen and Bremerhaven. The sediment contains organic and inorganic pollutants and hence is deposited on a landfill. Because of the limited capacity of that landfill alternative treatment techniques are investigated. This study aims to evaluate the production of Light Weight Aggregates (LWA) from harbour sediments with respect to the product quality and environmental aspects of the use of the LWA. 相似文献202.
Florian Chain Gérard Riault Maxime Trottet Emmanuel Jacquot 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(1):35-43
Serial passage experiments (SPE) of a Barley yellow dwarf virus-PAV (BYDV-PAV) isolate were performed on Zhong ZH and TC14 wheat lines to evaluate the durability of their resistance to BYDV. At different passage numbers (from the 2nd to the 114th), biological properties of the produced isolates were recorded either by monitoring infection percentages and virus titers of the first 3 weeks of viral infection or by measuring their impact on yield components. Statistical analyses using the area under pathogen progress curves and the area under concentration progress curves demonstrated that these two resistant lines induce, after only a few passages, a selection of variant(s) with significantly modified infection abilities. Isolates resulting from SPE performed on these lines induced important decreases of yield components. These results indicate that the use of Zhong ZH and TC14 lines in BYDV-resistant breeding programmes should be approached with caution. 相似文献
203.
Masabumi Komatsu Machiko Taniguchi Norihisa Matsushita Yukiko Takahashi Taizo Hogetsu 《Journal of General Plant Pathology》2010,76(6):363-369
Taphrina wiesneri, the pathogen of witches’ broom of cherry, is highly pathogenic to Cerasus × yedoensis, the most widely planted ornamental cherry species in Japan. For adequate control of this disease, it is necessary to understand
the life history of T. wiesneri. However, sites inhabited by T. wiesneri within infected trees are little understood, except during flowering and leafing periods in spring. Therefore, we attempted
to detect the location of T. wiesneri in shoots of witches’ broom before flowering and leafing in spring using PCR with a T. wiesneri-specific primer pair that was designed from 69 sequences in rDNA-internal transcribed spacer region of 32 Taphrina species. DNA extracted from symptomatic and asymptomatic C. × yedoensis sampled before leafing was amplified by PCR. T. wiesneri was detected in every bud and 5-mm stem segment of symptomatic shoots, except for one stem segment, and locally inside buds
and the inner bark of stem segments. These results indicate that T. wiesneri overwinters inside symptomatic shoots. Fungal hyphae were observed with an epifluorescence microscope in intercellular spaces
of young leaves in symptomatic buds but not in asymptomatic ones in thin sections stained with fluorescein-isothiocyanate-conjugated
concanavalin A. This observation supports the results of PCR detection. 相似文献
204.
Taissir Abou Al Fadil Alain Jauneau Yves Martinez Martina Rickauer Grégory Dechamp-Guillaume 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(1):93-103
Phoma macdonaldii, the causal agent of black stem disease of sunflower (Helianthus annuus), also attacks roots and collars of the plants, resulting in early death. Totally resistant lines do not exist for infection
of the aerial parts, but tolerant lines have been characterised. This paper presents a study on colonisation of a partially
resistant and a susceptible sunflower line by P. macdonaldii. The fungus was transformed with a constitutively expressed reporter gene encoding the jellyfish green fluorescent protein
via Agrobacterium tumefaciens, and colonisation of sunflower roots by this transformed strain was studied by various microscopy techniques including confocal
and scanning electron microscopy. The results show that penetration of the fungus into the root occurred through natural fissures
or through the epidermis and was similar in both lines. In contrast, the colonisation rate of the stele was reduced in the
partially resistant line, and the morphology of the fungal hyphae was also affected. The effect on hyphal morphology was strongest
in the stele, indicating a localised production of defence compounds in this line. 相似文献
205.
Mestorino N Formentini EA Lucas MF Fernandez C Modamio P Hernández EM Errecalde JO 《Veterinary research communications》2008,32(1):21-33
A comparative pharmacokinetic study was conducted to determine the order and the rate of absorption of triclabendazole (TCBZ)
in cattle and sheep. A commercial suspension of TCBZ (Biofasiolex, Biogénesis S.A., Argentina) was administered at a dose
rate of 10 mg/kg by the oral route to six Holstein female calves and six Corriedale female sheep. The plasma concentration
profiles of the metabolites triclabendazole sulfoxide (TCBZ-SO) and triclabendazole sulfone (TCBZ-SO2) were analysed by means of the non-compartmental method. The order of the absorption process of the active metabolite, TCBZ-SO,
was determined by construction of curves of cumulative absorbed fraction of the drug by means of the Wagner-Nelson method.
The appearance of TCBZ-SO in plasma of cattle and sheep resembles the entry of a constant quantity of drug into the organism
per unit time. This is explained by the reservoir effect of the rumen, which acts as a biological slow-release system for
TCBZ-SO and its precursor TCBZ to the posterior digestive tract where they are absorbed. The plasma concentration profiles
of TCBZ-SO in both species were well described by a one-compartment open model with zero-order process of absorption and first-order
process of elimination. The values of AUC0-∞ and C
max of TCBZ-SO did not differ between species, while other kinetic parameters except for λ
z
had higher values in calves than in sheep. In the case of TCBZ-SO2, t
max was the only parameter that did not differ between species, while other kinetic parameters except for λ
z
had higher values in calves than in sheep. 相似文献
206.
The effect of immunosuppression on protective immunity of turkey poults against infection with turkey coronavirus 总被引:2,自引:0,他引:2
Loa CC Lin TL Wu CC Bryan T Hooper T Schrader D 《Comparative immunology, microbiology and infectious diseases》2002,25(2):127-138
The objective of the present study was to evaluate the protective effect of humoral and cellular immunities on turkeys infected with turkey coronavirus (TCV). Two trials were conducted with two separate hatches of turkey poults. Turkey's were experimentally immunosuppressed with cyclosporin A (CsA) or cyclophosphamide (CY) and infected with TCV. Prior to infection, treatment with CsA selectively suppressed T cell activity as revealed by 2-3 fold decreased (p < 0.1) lymphocyte proliferation responses to a T cell mitogen, concanavalin A (Con A). Treatment with CY mainly induced B cell deficiency as indicated by significant reductions (p < 0.05) in antibody responses to sheep erythrocytes 7 days after injection. Body weight gain of turkeys treated with CY was significantly lower (p < 0.05) than that of untreated turkeys at 9 days post-infection (PI). Turkeys treated with CY had 1-2 fold higher immunofluorescent antibody assay (IFA) scores for TCV antigens (p < 0.05) in the intestine than untreated turkeys at 9 or 14 days PI. These results suggested that humoral immunity against TCV infection may be important in turkeys. 相似文献
207.
FlordeFátima Rosas-Cárdenas Noé Durán-Figueroa Jean-Philippe Vielle-Calzada Andrés Cruz-Hernández Nayelli Marsch-Martínez Stefan de Folter 《Plant methods》2011,7(1):4
Background
Small RNAs emerged over the last decade as key regulators in diverse biological processes in eukaryotic organisms. To identify and study small RNAs, good and efficient protocols are necessary to isolate them, which sometimes may be challenging due to the composition of specific tissues of certain plant species. Here we describe a simple and efficient method to isolate small RNAs from different plant species. 相似文献208.
Because of their highly polymorphic shell patterns, Cepaea land snails have been the subject of numerous studies in ecological genetics. Here, we investigated the spatial structure
of polychromatism in Cepaea hortensis in agricultural landscapes with zones from low to high hedgerow densities. Our main purpose was to search for a relationship
between landscape composition and spatial structuring of chromatism. Despite significant spatial heterogeneity in the three
landscapes sampled, only the high hedgerow density landscape showed a significant spatial structuring of shell polymorphism.
In order to understand this result, an investigation of daily movement patterns in relation to habitat form was carried out
on a mark-release experiment under semi-artificial conditions. This experiment revealed a strong influence of a linear corridor
on snail dispersal. In the field, spatial heterogeneity of shell polymorphism, related to the effects of genetic drift, was
shaped by restricted dispersal in narrow corridors. In the more enclosed one, i.e. where hedgerow density was the highest,
the significant spatial structure we detected involved a balance between local genetic drift and environmentally mediated
gene flow. This isolation-by-distance pattern resulted from direct gene exchange through fields between neighbouring populations.
When applying landscape distances based on hedgerow length, no significant spatial correlation with polychromatism was found.
In the more fragmented sites, random genetic drift seemed to be the prevailing force and, at the scale of the whole sampled
area, selective pressures potentially interfere with these genetic drift-dispersal events. 相似文献
209.
Context
Freshwater ecosystems depend on surrounding terrestrial landscape for resources. Most important are terrestrial leaf litter subsidies, which differ depending on land use. We lack a good understanding of the variation of these inputs across spatial scales.Objectives
We sought to determine: (1) the relative importance of local versus catchment-level forestation for benthic leaf litter biomass in streams, (2) how landscape configuration alters these relationships, and (3) how land use affects the quality and diversity of leaf litter subsidies.Methods
We measured biomass and identity of benthic leaf litter in 121 reaches in 10 independent catchments seasonally over the course of a year. We assessed direct and indirect effects of forestation, reach position, and seasonality on leaf litter biomass using structural equation models, and assessed how leaf litter diversity varied with land use.Results
In catchments with forested headwaters, the degree of forestation and reach position in the catchment influenced benthic leaf litter biomass indirectly through local reach-scale forestation. In catchments where forest was only located downstream, or with minimal forest, none of these factors influenced reach-level benthic leaf litter. Leaf litter diversity peaked in fall in all land use types, but was generally lowest in forested reaches.Conclusions
Not only habitat amount, but its location relative to other habitats is important for ecosystem function in the context of cross-ecosystem material flows. Here, lack of upstream forest altered spatial patterns of leaf litter storage. Studies with high spatiotemporal resolution may further reveal effects of landscape configuration on other ecosystems.210.
Chun-Lian Wang An-Bi Xu Ying Gao Ying-Lun Fan Yun-Tao Liang Chong-Ke Zheng Liang-Qing Sun Wen-Quan Wang Kai-Jun Zhao 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(3):343-351
Xanthomonas oryzae pv. oryzae causes bacterial blight of rice. Xa23, a bacterial blight resistance gene identified originally in wild rice, Oryza rufipogon, is dominant and resistant to all X. oryzae pv. oryzae field isolates tested. The corresponding avirulence gene avrXa23 is unknown. Here we report the generation of a random insertion mutant library of X. oryzae pv. oryzae strain PXO99 using a Tn5-derived transposon tagging system, and identification of mutant strains that are virulent on CBB23,
a near-isogenic rice line containing Xa23. A total of 24,192 Tn5 inserted clones was screened on CBB23 by leaf-cutting inoculation and at least eight of them caused
lesions on CBB23 comparable to those on JG30, the susceptible recurrent parent of CBB23. Polymerase chain reaction and Southern
blot analysis showed that all the eight mutants, designated as P99M1, P99M2, P99M3, P99M4, P99M5, P99M6, P99M7 and P99M8,
have a single Tn5-insertion in their genomes. The flanking DNA sequences of the Tn5-insertion sites were isolated by PCR-walking
and sequenced. Bioinformatic analysis of the flanking sequences, by aligning them with the whole genome sequences of X. oryzae pv. oryzae strains PXO99, KACC10331 and MAFF311018 through NCBI, revealed that the Tn5-insertions disrupted genes that encode TAL effector
AvrBs3/PthA, ISXo1 transposase, Type II secretion system protein-like protein or outer membrane protein, glycogen synthase,
cytochrome C5 and conserved hypothetical protein. Further identification of these mutants will facilitate the molecular cloning
of avirulence gene avrXa23.
The authors C.-L. Wang, A.-B. Xu contributed equally to this work; Y. Gao and Y.-L. Fan contributed equally to this work. 相似文献