Quail cell lines supporting replication of Marek's disease virus serotype 1 and 2 and herpesvirus of turkeys     

Li X  Schat KA 《Avian diseases》2004,48(4):803-812

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Cytotoxic T lymphocyte responses to Marek's disease herpesvirus-encoded glycoproteins     

Markowski-Grimsrud CJ  Schat KA 《Veterinary immunology and immunopathology》2002,90(3-4):133-144

Cell-mediated immune responses are important for protective immunity to Marek’s disease (MD), especially because MD herpesvirus (MDV) infection is strictly cell-associated in chickens with the exception of the feather follicle epithelium. A system previously developed using reticuloendotheliosis (REV)-transformed cell lines stably expressing individual MDV genes allows the determination of relevant MDV proteins for the induction of cytotoxic T lymphocyte (CTL) responses. To examine the importance of glycoproteins for the induction of CTL, the MDV genes coding for glycoproteins (g) C, D, E, H, I, K, L, and M were stably transfected into the REV-transformed chicken cell lines RECC-CU205 (major histocompatibility complex (MHC): B²¹B²¹) and RECC-CU91 (MHC: B¹⁹B¹⁹). All transfected cell lines were lysed by REV-sensitized, syngeneic splenocytes obtained from MD-resistant N2a (MHC: B²¹B²¹) and MD-susceptible P2a (MHC: B¹⁹B¹⁹) chickens, indicating that the expression of individual MDV glycoproteins did not interfere with antigen processing pathways. Only cell lines expressing gI were recognized by CTL from both N2a and P2a MDV-infected chickens. Cell lines expressing glycoproteins gC and gK, and to a lesser extent, gH, gL, and gM were lysed by syngeneic MDV-sensitized splenocytes from N2a birds but not P2a birds. In contrast, gE was recognized by MDV-sensitized effector cells from the P2a line and not the N2a line. Glycoprotein D was not recognized by either line, with the exception of one marginally significant P2a assay. These results indicate that late viral glycoproteins are relevant for the induction of cell-mediated immunity during MDV infection.  相似文献   

Toxin production by and adhesive properties of Clostridium difficile isolated from humans and horses with antibiotic-associated diarrhea     

Taha S  Johansson O  Rivera Jonsson S  Heimer D  Krovacek K 《Comparative immunology, microbiology and infectious diseases》2007,30(3):163-174

Clostridium difficile is a common nosocomial pathogen in humans and animals that causes diarrhea and colitis following antibiotic therapy. Isolates of C. difficile obtained from faecal material from 20 human patients and 6 equine subjects with antibiotic-associated diarrhea were investigated regarding production of toxins A and B, their capacity to adhere to the human intestinal Caco-2 cell line and equine intestinal cells, and for the presence of fimbriae. The results showed that most (17/20) of the human clinical isolates produced both toxins A and B. One of the human isolates proved toxin A-negative/toxin B-positive. All (6/6) horse isolates were positive for both toxins A and B. Both the human and horse isolates possessed the capacity to adhere, to varying degree, to human and equine intestinal cells. It appeared that human isolates produced greater amounts of toxin B, and that there was a host-species dependency on ability to attach to intestinal epithelial cells. No fimbriae were found in any of the investigated isolates.  相似文献   

Reservoirs' siltation measurments and sediment transport assessment in the Czech Republic, the Vrchlice catchment study     

Josef Krasa  Tomas Dostal  Anton Van Rompaey  Jiri Vaska  Karel Vrana 《CATENA》2005,64(2-3):348

Sediment transport from agricultural land into rivers and reservoirs is a problem within the Czech Republic. This problem was highly accelerated almost 50 years ago during the communist period. At that time strong collectivization was undertaken leading to destruction of traditional landscape patterns, surface outflow, erosion processes intensification and surface water quality deterioration. Thirteen years after political changes erosion problems remain.At the Department of Irrigation, Drainage and Landscape Engineering at the CTU Prague there has been continuous research undertaken in the field of erosion and sediment transport assessment. There are several modelling tools available for this purpose. One of them—USLE (Universal Soil Loss Equation) is commonly used in the Czech Republic for many years at a plot-scale but modern GIS (geographical information systems) tools in computer science allow using it at larger scales. Very important is the validation of this model for two-dimensional topography and GIS routines. Moreover USLE produces only local erosion amount values and has to be completed by another tool to get sediment amounts. For this purpose SDR (sediment delivery ratio) is usually used, applying a lumped approach—total erosion of every watershed is reduced by SDR and by pond’s trapping efficiency. Another available approach is using the Watem/SEDEM model that puts together RUSLE (Revised USLE) and a distributive approach to sediment transport modelling. This has already been used for estimating sediment amount in several catchments of the Czech Republic, but has to be validated as well.At the Dept. of Drainage, Irrigation and Landscape Engineering there are datasets of sediment amount from different reservoirs available and other reservoirs are to be measured soon. As the dataset of various watersheds is expanded, a methodology for sediment amount measurements is needed. The main objective of this paper is to propose a simple methodology to measure the sediment amount within reservoirs as well as to present a review of available methods. The application of the methodology at Vrchlice Catchments (97 km²) case study is presented. Total sediment amounts between 125 000140 000 m³ were measured in Vrchlice reservoir and values of 110 976 m³ (using USLE), resp. 105833 m³ (using Watem/SEDEM) were predicted by the erosion models. For catchments of this scale it is a sufficient validation.  相似文献   

Behavior of runoff-derived metals in a detention pond system     

Karel Mesuere  William Fish 《Water, air, and soil pollution》1989,47(1-2):125-138

The removal and fate of runoff-derived heavy metals in a 1-yr old detention pond system were investigated during climatic conditions typical of the U.S. maritime Northwest. The catchment was a medium-sized, suburban parking lot near Portland, Oregon. Water samples from runoff, the detention pond system, and pond effluent were collected and analyzed for dissolved and particulate Cu. Copper was the dominant toxic metal for the study site, while analysis of selected samples for Pb and Cd showed these metals to be minor pollutants. Total Cu in runoff varied among different storm events over a wide range of concentrations (< 2 to 33 µg L^?1), while total Cu levels in pond effluent remained within a fairly narrow range (5 to 12 µg L^?1), Sediment samples collected from the detention pond system were analyzed for Cu in two size fractions (< 63 µm and < 125 µm). Copper was found to be deposited in the pond sediments in a small but highly concentrated plume (up to 130 mg kg^?1), extending axially from the runoff inlet pipe. Overall, results from this study showed that low-cost, small-scale detention ponds can be a useful management practice for runoff from parking lot areas and can be of value in preserving the integrity of receiving waters.  相似文献   

Toxicity of ggr-Benzene Hexachloride in Clothing     

Horton RG  Karel L  Chadwick LE 《Science (New York, N.Y.)》1948,107(2775):246-247

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The influence of bark beetles outbreak vs. salvage logging on ground layer vegetation in Central European mountain spruce forests     

Magda Jonášová  Karel Prach 《Biological conservation》2008,141(6):1525-1535

Changes in the herb and moss layers of mountain spruce (Picea abies (L.) Karst.) forests after bark beetle (Ips typographus (L.)) outbreak were compared with and without forestry intervention. The study area is situated in the Šumava National Park (Czech Republic, Central Europe), where an extensive bark beetle outbreak occurred in the 1990s. Parts of forests were left without interventions, while salvage logging was applied in other areas. Altogether, 18 permanent research plots were established in: (1) climax stands with completely dead canopy, (2) climax stands where salvage logging was applied (clearcuts), and (3) waterlogged stands with only partly dead canopy. Vegetation composition of the ground layer and species numbers were evaluated in 1997 and 2002.The effect of salvage logging on vegetation was greater than that of the bark beetle outbreak itself. Forest herb species and partly also bryophytes survived relatively well under untouched dead canopy. The fewest changes occurred under the partly dead canopy in waterlogged forests. The herb layer expanded in clearcuts originated due to salvage logging, being dominated by grasses. Bryophytes were more susceptible to logging than herbs; their cover in clearcuts was markedly lower and composition changed towards pioneer species. The results show that a natural succession of mountain spruce forests after a bark beetle outbreak, if left without interventions, will probably avoid a pioneer stage and direct recovery of the forests will be possible. Salvage logging had negative effects on species composition of the spruce forests, delayed the forest recovery, and should not be permitted in the national park.  相似文献   

Fish and mussels: Importance of fish for freshwater mussel conservation          下载免费PDF全文

Vanessa Modesto  Martina Ilarri  Allan T Souza  Manuel Lopes‐Lima  Karel Douda  Miguel Clavero  Ronaldo Sousa 《Fish and Fisheries》2018,19(2):244-259

Co‐extinctions are increasingly recognized as one of the major processes leading to the global biodiversity crisis, but there is still limited scientific evidence on the magnitude of potential impacts and causal mechanisms responsible for the decline of affiliate (dependent) species. Freshwater mussels (Bivalvia, Unionida), one of the most threatened faunal groups on Earth, need to pass through a parasitic larval (glochidia) phase using fishes as hosts to complete their life cycle. Here, we provide a synthesis of published evidence on the fish–mussel relationship to explore possible patterns in co‐extinction risk and discuss the main threats affecting this interaction. We retrieved 205 publications until December 2015, most of which were performed in North America, completed under laboratory conditions and were aimed at characterizing the life cycle and/or determining the suitable fish hosts for freshwater mussels. Mussel species were reported to infest between one and 53 fish species, with some fish families (e.g., Cyprinidae and Percidae) being used more often as hosts than others. No relationship was found between the breadth of host use and the extinction risk of freshwater mussels. Very few studies focused on threats affecting the fish–mussel relationship, a knowledge gap that may impair the application of future conservation measures. Here, we identify a variety of threats that may negatively affect fish species, document and discuss the concomitant impacts on freshwater mussels, and suggest directions for future studies.  相似文献   

Coastal zone planning: a geophysical classification of inlets to define ecological representation     

Michelle E. Greenlaw  John C. Roff  Anna M. Redden  Karel A. Allard 《水产资源保护:海洋与淡水生态系统》2011,21(5):448-461

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Inhibition of fungal pathogens of woody plants by the plant growth regulator paclobutrazol     

Karel A Jacobs  Lisa C Berg 《Pest management science》2000,56(5):407-412

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