Expression of interferon gamma in the brain of cats with natural Borna disease virus infection     

Wensman JJ  Ilbäck C  Hjertström E  Blomström AL  Gustavsson MH  Jäderlund KH  Ström-Holst B  Belák S  Berg AL  Berg M 《Veterinary immunology and immunopathology》2011,141(1-2):162-167

Borna disease virus (BDV) is a neurotropic, negative-stranded RNA virus, which causes a non-suppurative meningoencephalomyelitis in a wide range of animals. In cats, BDV infection leads to staggering disease. In spite of a vigorous immune response the virus persists in the central nervous system (CNS) in both experimentally and naturally infected animals. Since the CNS is vulnerable to cytotoxic effects mediated via NK-cells and cytotoxic T-cells, other non-cytolytic mechanisms such as the interferon (IFN) system is favourable for viral clearance. In this study, IFN-γ expression in the brain of cats with clinical signs of staggering disease (N=12) was compared to the expression in cats with no signs of this disease (N=7) by quantitative RT-PCR. The IFN-γ expression was normalised against the expression of three reference genes (HPRT, RPS7, YWHAZ). Cats with staggering disease had significantly higher expression of IFN-γ compared to the control cats (p-value ≤ 0.001). There was no significant difference of the IFN-γ expression in BDV-positive (N=7) and -negative (N=5) cats having clinical signs of staggering disease. However, as BDV-RNA still could be detected, despite an intense IFN-γ expression, BDV needs to have mechanisms to evade this antiviral immune response of the host, to be able to persist.  相似文献   

A new resorbable device for ligation of blood vessels - A pilot study     

Odd V H?glund  Ragnvi Hagman  Kerstin Olsson  Jonas Mindemark  Niklas Borg  Anne-Sofie Lagerstedt 《Acta veterinaria Scandinavica》2011,53(1):47

Background

During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency.

Methods

The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version.The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs.

Results

The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, n = 11) and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, n = 11). Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance.Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached to the ovarian pedicle could be seen with ultrasound, and vessel compression and occlusion were verified by histology.

Conclusions

Tests of functionality of the device showed complete haemostasis and good tissue grip. Devices with a band of sufficient length were easily applied and tightened in tissue.  相似文献   

The potential of microdialysis to monitor organic and inorganic nitrogen compounds in soil     

Erich Inselsbacher  Jonas Öhlund  Sandra Jämtgård  Kerstin Huss-Danell 《Soil biology & biochemistry》2011,43(6):1321-1332

Plant nitrogen (N) acquisition is strongly controlled by the concentration of available inorganic and organic N in the soil solution and by biogeochemical processes in the rhizosphere. However, until now it was hardly possible to reliably estimate plant-available N in soil microsites. Here, a novel microdialysis approach based on passive diffusion sampling is presented and compared qualitatively and quantitatively with lysimeter and soil extraction techniques when analyzing two contrasting boreal soils. Further, preliminary dialysis membrane calibration issues for sampling plant-available N compounds are discussed. Due to its miniaturized design microdialysis was shown to be a suitable tool for continuous sampling of ammonium, nitrate and free amino acids from the soil solution with only minimal disturbance of the soil structure. Microdialysis proved to be outstanding regarding the possible spatial (<0.5 mm) and temporal (<30 min) resolution of soil solution N chemistry. The different methods for soil N sampling resulted in significantly different results. In lysimeter and soil extraction samples, nitrate and ammonium were found at the highest concentrations, while results from microdialysis revealed that the pool of plant-available amino acids was contributing most to the total N pool tested. Application of a standard N solution to the tested soils led to an immediate peak of recovery via the microdialysis probes followed by a rapid decrease due to the formation of a depletion zone at the probe surfaces. Therefore, this relatively new technique will not only provide essential data on diffusion rates of a variety of N compounds in the soil but might be used for monitoring quantitative and qualitative changes in plant-available N in soil microsites such as the rhizosphere.  相似文献   

Haemolysis of human erythrocytes heavily sensitized with sheep amboceptor by sheep complement chelated with EGTA or Mg²⁺-EGTA     

M. Stankiewicz  W. Jonas 《Veterinary immunology and immunopathology》1981,2(3):253-264

Human erythrocytes sensitized with an agglutinating dose of either sheep anti-human erythrocyte antiserum, IgM, slow or fast γ-globulin antibody are haemolysed by foetal lamb or sheep serum complement (C) in the presence of ethyleneglycoltetraacetic acid (EGTA) or Mg²⁺-EGTA but not ethylenediaminetetraacetic acid (EDTA) or triethylenetetraminehexaacetic acid (TTHA). Dialysis of the C source against phosphate buffered saline rendered it inactive, but addition of Mg²⁺ or Mg²⁺-EGTA restored haemolytic activity. Haemolysis of sensitized erythrocytes took place more rapidly in buffer containing Ca²⁺ and Mg²⁺ than in EGTA or Mg²⁺-EGTA. Heating the C source at 50 °C for 30 min or 56 °C for 3 min abolished haemolytic activity. In the presence of EGTA or Mg²⁺-EGTA, haemolytic activity was restored to 50 °C-heated serum by a CM-cellulose fraction that contained sheep factor B.These results show that sheep C, in the presence of EGTA or Mg²⁺-EGTA will haemolyse human erythrocytes heavily sensitized with sheep amboceptor. The alternative pathway of sheep C is thought to be involved.  相似文献   

Multi-temporal wheat disease detection by multi-spectral remote sensing   总被引：2，自引：1，他引：2  

Jonas Franke  Gunter Menz 《Precision Agriculture》2007,8(3):161-172

For the implementation of site-specific fungicide applications, the spatio-temporal dynamics of crop diseases must be well known. Remote sensing can be a useful tool to monitor the heterogeneity of crop vitality within agricultural sites. However, the identification of fungal infections at an early growth stage is essential. This study examines the potential of multi-spectral remote sensing for a multi-temporal analysis of crop diseases. Within an experimental field, a 6 ha plot of winter wheat was grown, containing all possible infective stages of the powdery mildew (Blumeria graminis) and leaf rust (Puccinia recondita) pathogens. Three high-resolution remote sensing images were used to execute a spatio-temporal analysis of the infection dynamics. A decision tree, using mixture tuned matched filtering (MTMF) results and the Normalized Difference Vegetation Index (NDVI), was applied to classify the data into areas showing different levels of disease severity. Classification results were compared to ground truth data. The classification accuracy of the first scene was only 56.8%, whereas the scenes from May 28^th and June 20^th achieved considerably higher accuracies of 65.9% and 88.6% respectively. The results showed that high-resolution multi-spectral data are generally suitable to detect in-field heterogeneities of crop vigour but are only moderately suitable for early detection of crop infections.

Jonas FrankeEmail:

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The uptake and destruction of Salmonella typhimurium by some body tissues of sheep     

W.E. Jonas B.V.Sc. Ph.D.  H.D. Pulford  Susan Broad 《New Zealand veterinary journal》2013,61(1-2):17-25

A developmental anomaly, resulting from partial segmental aplasia of the Mullerian ducts, was present in a Clydesdale mare. She had complete double cervices and a divided uterine body. In this mare, bilateral pregnancies were destroyed in sequence by squeezing them per rectum 25 and 29 days after insemination.  相似文献   

Fenbendazole and its effect on the immune system of the sheep     

W. Cabaj  M. Stankiewicz  W.E. Jonas  L.G. Moore 《New Zealand veterinary journal》2013,61(6):216-220

Ten parasite-free 6-month-old lambs were drenched on days 0 and 28 with fenbendazole and 1 day after each drench were injected with human erythrocytes and ovalbumin. Ten other lambs injected with the antigens were not drenched with anthelmintic and served as controls. Lymphocytes from the fenbendazole-drenched lambs collected 3 days after the first antigen injections and cultured in vitro in RPM11640 plus 5% foetal calf serum, and lymphocytes collected at 3 and 7 days and cultured in RPM1 plus 50% autologous serum, had decreased blastogenic activity compared with lymphocytes from control lambs. Similiarly, decreased blastogenesis was observed with lymphocytes collected 7 days after the second antigen injections from drenched lambs and cultured in 50% autologous serum containing concanavalin A. In contrast, increased blastogenesis was seen with lymphocytes collected 14 days after the second antigen injections from the drenched lambs and cultured in 50% autologous serum containing phytohaemagglutinin. Similar antibody responses were seen for the drenched and control lambs in response to the injections of both antigens except that, after the second injection, there was a significant reduction in antibody response to human erythrocytes in the fenbendazole-treated lambs. Decreased serum complement levels were seen particularly 3 and 7 days after the second antigen injections in drenched lambs. These serum samples had increased conglutinin activity. At the end of the experiment, the fenbendazole-drenched lambs were significantly heavier than the control lambs. However, this did not appear to be related to any effects of fenbendazole on levels of growth promoting hormones.  相似文献   

Classifying fishers' behaviour. An invitation to fishing styles          下载免费PDF全文

Wiebren J Boonstra  Jonas Hentati‐Sundberg 《Fish and Fisheries》2016,17(1):78-100

The study and classification of fishers' behaviour remains a much debated topic. There is a tension between detailed empirical studies, which highlight the variety and diversity of fisheries, and the parsimony and generalization required to satisfy science and policy demands. This study contributes to this debate. The first section reviews quantitative methods currently used for classifying fishing practices. The review uncovers significant weaknesses in quantitative classification methods, which, we argue, can be improved through the complementary use of qualitative methods. To this purpose, we introduce the concept of ‘fishing style’, which integrates quantitative classification methods with qualitative analysis. We explain the scientific premises of the fishing‐style concept, outline a general methodological framework and present a fishing‐style analysis of Swedish Baltic Sea fisheries. Based on these results, we conclude that it is possible to classify fishing practices in a relatively uniform and limited number of styles that can highlight the rich, empirical diversity of fishers' behaviour. We therefore propose that fishing‐style analysis, based on an integration of quantitative and qualitative methods, can be an important step towards more effective and sustainable fisheries management.  相似文献   

Deciduous forest mapping using change detection of multi-temporal canopy height models from aerial images acquired at leaf-on and leaf-off conditions     

Jonas Bohlin  Jörgen Wallerman  Johan E. S. Fransson 《Scandinavian Journal of Forest Research》2016,31(5):517-525

Discrimination of deciduous trees using spectral information from aerial images has only been partly successfully due to the complexity of the reflectance at different view angles, times of acquisition, phenology of the trees and inter-tree radiance. Therefore, the objective was to evaluate the accuracy of estimating the proportion of deciduous stem volume (P) utilizing change detection between canopy height models (CHMs) generated by digital photogrammetry from leaf-on and leaf-off aerial images instead of using spectral information. The study was conducted at a hemi-boreal study area in Sweden. Using aerial images from three seasons, CHMs with a resolution of approximately 0.5?m were generated using semi-global matching. For training plots, metrics describing the change between leaf-on and leaf-off conditions were calculated and used to model the continuous variable P, using the Random Forest approach. Validated at sub-stands, the estimation accuracy of P in terms of root mean square error and bias was found to be 18% and ?6%, respectively. The overall classification accuracy, using four equally wide classes, was 83% with a kappa value of 0.68. The validation plots in classes of high proportion of coniferous or deciduous stem volume were well classified, whereas the mixed forest classes showed lower classification accuracies.  相似文献   

Common Bean Productivity Following Diverse Boron Applications on Soil     

Rilner Alves Flores  Talles Victor Silva  Virgínia Damin  Renata de Castro Marques Carvalho  Débora Regina Marques Pereira  Jonas Pereira de Souza Junior 《Communications in Soil Science and Plant Analysis》2018,49(6):725-734

Aspects related to micronutrients management are still poorly studied and need to be clarified to guarantee sustainable production. In this way, the study aimed to evaluate boron (B) fertilization effects on nutrition and production of common beans. The parameters measured were relative chlorophyll index, dry mass, boron transport, utilization and absorption efficiencies, B content, and B accumulation in plant tissues. The study showed that the dry mass production was negatively affected by B application, with linear dry mass decrease following the increase of B doses. Accordingly, it was found that the common bean cultivar Esplendor presented high absorption capacity of boron, and can reach 175 mg kg^?1. However, the high absorption caused phytotoxicity and reduced dry matter production by up to 30%, reflecting the efficiency of boron use by the plant, which was reduced in up to 75%.  相似文献