Differentiation of Actinobacillus pleuropneumoniae by PCR-REA based on sequence variability of the apxIVA gene and by ribotyping   总被引：1，自引：0，他引：1  

Jaglic Z  Svastova P  Rychlik I  Nedbalcova K  Kucerova Z  Pavlik I  Bartos M 《Veterinary microbiology》2004,103(1-2):63-69

During the period of 2001-2003, a total of 591 Actinobacillus pleuropneumoniae field isolates from the Czech Republic were serotyped with a high occurrence of cross-reactions. The cross-reactions were observed in 416 isolates. Most frequently, in 401 isolates (67.9%), cross-reactions with antisera specific for serotypes 9, 11, and/or 1 were observed. Two additional molecular methods, ribotyping and restriction analysis of PCR amplified apxIVA gene (PCR-REA), were therefore used for detailed characterisation of A. pleuropneumoniae. In this subsequent analysis, reference strains representing serotypes 1-12 and 25 field isolates showing the most frequent serotype cross-reactions were examined. PCR-REA enabled all reference strains to be distinguished except for the strains of serotypes 9 and 11. Ribotyping distinguished all reference strains except two pairs of serotypes: 3 versus 6, and 9 versus 11, respectively. Field isolates with serotype cross-reactivity 9, 11, and/or 1 could not be differentiated by either of these methods.  相似文献   

Indicators of nitrogen status for ornamental woody plants based on optical measurements of leaf epidermal polyphenol and chlorophyll contents     

Sabine Demotes-Mainard  Rachid Boumaza  Sylvie Meyer  Zoran G. Cerovic 《Scientia Horticulturae》2008

Indicators of plant nitrogen (N) status adapted to woody ornamental plants are essential for the adjustment of fertilization practices in nurseries. The objective of this study was to investigate whether optical measurements of leaf epidermal polyphenol (EPhen) and chlorophyll (Chl) contents could be used as N status indicators for woody deciduous and evergreen ornamental plants. One-year-old plants of Lagerstroemia indica, Callicarpa bodinieri and Viburnum tinus were grown outdoors in containers. They received low (TN₁, 4 mg L⁻¹) or high (TN₂, 105 mg L⁻¹) levels of N during 2 months in spring and summer. TN₁ treatment limited shoot growth from 28 to 37 days after treatment initiation in Lagerstroemia and Callicarpa, respectively. Shoot growth was unaffected until day 176 in Viburnum. The mass-based leaf N content (N_M) of a sample of young expanded leaves exposed to direct sunlight was tightly correlated with shoot N content and differentiated treatments several weeks before shoot growth reduction for the three species. N_M was therefore used as an index of plant N status. EPhen and Chl contents were recorded with Dualex™ and SPAD-502 leaf-clip meters, respectively. Dualex values were strongly and negatively correlated with N_M, and differentiated the treatments early in the experiment, in all three species. SPAD values were positively correlated with N_M for Lagerstroemia and Callicarpa, but not for Viburnum, because large variations in leaf mass per area (LMA) in this species compensated for variations in leaf dry mass invested in Chl. The SPAD/Dualex ratio was used to assess changes in the proportion of leaf dry mass allocated to proteins and polyphenols in response to fertilization. It differentiated between the treatments early in the experiment and was correlated with N_M in all three species.  相似文献   

OUTCOMES AND PROGNOSTIC FACTORS ASSOCIATED WITH CANINE SINONASAL TUMORS TREATED WITH CURATIVE INTENT CONE‐BASED STEREOTACTIC RADIOSURGERY (1999–2013)          下载免费PDF全文

Lyndsay Kubicek  Rowan Milner  Qi An  Kelvin Kow  Myron Chang  Kristen Cooke  Leslie Fox  James Farese  Nicholas Bacon  David Lurie 《Veterinary radiology & ultrasound》2016,57(3):331-340

Stereotactic radiosurgery (SRS) is a relatively new therapeutic option in veterinary oncology. The role of this modality has not been extensively evaluated for the use in canine nasal tumors. The objective of this retrospective, observational study was to describe the clinical outcome and prognostic factors associated with survival times in a sample of canine patients treated with SRS for sinonasal tumors. Fifty‐seven dogs with sinonasal tumors met inclusion criteria. Histologic diagnoses included sarcoma (SA) (n = 9), carcinoma (CA) (n = 40), osteosarcoma (OSA) (n = 7), and round cell (n = 1). Four of 57 cases were treated twice with SRS. For these, the median and mean doses delivered were 30Gy and 33Gy, respectively (range 18.75Gy–56Gy). Late effects occurred in 23 cases and ranged from grades I–III. The median overall survival time was 8.5 months. The median overall survival times in dogs with tumor type of CA, SA, and OSA were 10.4, 10.7, and 3.1 months, respectively. Dogs with the tumor type of OSA had shorter overall survival time than that in dogs with tumor type of CA and SA. Findings from this retrospective study indicated that SRS may be beneficial for canine patients with sinonasal tumors, however a controlled clinical trial would be needed to confirm this. Prospective studies are also needed to better define the role of SRS as palliative or curative, and to further investigate the risk of clinically significant toxicity.  相似文献   

ASSOCIATION BETWEEN COMPUTED TOMOGRAPHIC CHARACTERISTICS AND FRACTURES FOLLOWING STEREOTACTIC RADIOSURGERY IN DOGS WITH APPENDICULAR OSTEOSARCOMA          下载免费PDF全文

Lyndsay Kubicek  Daniel Vanderhart  Kimberly Wirth  Qi An  Myron Chang  James Farese  Francis Bova  Atchar Sudhyadhom  Kelvin Kow  Nicholas J. Bacon  Rowan Milner 《Veterinary radiology & ultrasound》2016,57(3):321-330

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Fast and local assessment of stilbene content in grapevine leaf by in vivo fluorometry   总被引：2，自引：0，他引：2  

Poutaraud A  Latouche G  Martins S  Meyer S  Merdinoglu D  Cerovic ZG 《Journal of agricultural and food chemistry》2007,55(13):4913-4920

Stilbenes are grapevine phytoalexins. These highly fluorescent molecules are generally analyzed by HPLC. This technique allows accurate assay of different stilbenes, but it is destructive, time-consuming, and neglects their spatial distribution. This is why we have tested a new method based on in vivo fluorescence using commercial spectrofluorometers that allowed fast and local assessment of stilbene content in grapevine leaves. Stilbene synthesis in grapevine Vitis vinifera var. Muscat Ottonel leaves was induced by Plasmopara viticola inoculation or UV-C irradiation. Fluorescence was measured both from the abaxial and adaxial sides of leaves, then stilbene content was analyzed by HPLC. It varied from 0 in control leaves to 15 mg g-1 dry weight in UV-treated leaves. Highly significant regressions were found between HPLC stilbene content and the corresponding leaf UV-induced blue fluorescence. Thus, in vivo fluorescence is a good tool for a rapid study of stilbenes synthesis in grapevine leaves that can potentially be extended to other fluorescent molecules.  相似文献   

American Association of Feline Practitioners. Senior Care Guidelines     

Jeanne Pittari DVM DABVP  Co-Chair  AAFP Senior Care Guidelines Panel  Ilona Rodan DVM DABVP  Co-Chair  AAFP Senior Care Guidelines Panel  Gerard Beekman DVM  Danille Gunn-Moore BVM&#x;S PhD MACVSc MRCVS RCVS  Specialist in Feline Medicine  David Polzin DVM PhD DACVIM-SAIM  Joseph Taboada DVM DACVIM-SAIM  Helen Tuzio DVM DABVP  Debra Zoran DVM PhD DACVIM-SAIM 《Journal of Feline Medicine and Surgery》2009,11(9):763-778

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Importance of biological processes in the sulfur budget of a northern hardwood ecosystem   总被引：4，自引：0，他引：4  

Mark B. David  Myron J. Mitchell  Thomas J. Scott 《Biology and Fertility of Soils》1987,5(3):258-264

Summary Total S, organic S and sulfate were measured in foliage, litter, roots, soil and solutions at a hardwood site within the Adirondack Mountains of New York. Sulfate as a percentage of total S was similar in foliage and litter (10%), but was greater in roots (30%). Sulfur constituents in the hardwood forest ecosystem were dominated by C-bonded S (60 g m^–2) and ester sulfate (16 g m^–2) which are formed by biological processes. Because sulfur mineralization (1.42 g m^–2 yr^–1) was greater than wet precipitation inputs (0.82 g m^–2 yr^–1), those factors that influence mineralization-immobilization processes are important in evaluating S cycling and sulfate fluxes in this ecosystem. Ester sulfate was formed within the forest floor by the soil biota and was leached to mineral horizons. Annual turnover of this pool was high (25%) within the mineral forest floor. Forest-floor C-bonded S was derived from root and above-ground litter, and substantial amounts were leached to mineral horizons. Calculated storage + outputs (1.64 g m^–2 yr^–1) was much greater than wet inputs (0.82 g m^–2 yr^–1).  相似文献   

In-lake alkalinity generation by sulfate reduction: A paleolimnological assessment     

Stephen A. Norton  Myron J. Mitchell  Jeffrey S. Kahl  George F. Brewer 《Water, air, and soil pollution》1988,39(1-2):33-45

The generation of alkalinity by SO₄ reduction and net storage of reduced S in lake sediments has been estimated from an analysis of sediment cores from 16 lakes in ME, VT, NY, MI, MN, and WY. The cores have been dated by ²¹⁰Pb. The rate of pre-1850 (background) storage of S in lake sediments suggests that alkalinity contribution to lake water from this process ranged from 0.2 to 9.3 geq L^?1, with an average of 4 geq L^?1, Background values are similar for all lakes and remain low in the WY lakes up to the present. Maximum alkalinity contributions recorded in sediment, from upper mid-west and eastern lakes, dated between 1850 and 1985 are between 0.4 and 33 geq L^?1, with a lake mean maximum of 9.9 geq L^?1, Significant increases in recent S storage only occur in eastern lakes. Average values for net S accumulation in the sediment of most lakes for post-1850 sediment are typically less than half of maximum values.  相似文献   

Organic fertilizer amendment promotes wheat resistance to herbivory and biocontrol services via bottom-up effects in agroecosystems     

Gu  Shimin  Zalucki  Myron P.  Men  Xingyuan  Li  Jing  Hou  Ruixing  Zhang  Qingqing  Ge  Feng  Ouyang  Fang 《Journal of pest science》2022,95(1):339-350

Journal of Pest Science - Excessive mineral fertilizer input results in little extra yield but exacerbates insect herbivory and affects environmental health and ecosystem services. The use of...  相似文献   

Nitrate dynamics of forested watersheds: spatial and temporal patterns in North America,Europe and Japan     

Myron J. Mitchell 《Journal of Forest Research》2011,16(5):333-340

The relationships of nitrogen biogeochemistry are reviewed, focusing on forested watersheds in North America, Europe and Japan. Changes in both local and global nitrogen cycles that affect the structure and function of ecosystems are described. Within northeastern United States and Europe, atmospheric deposition thresholds of ~8 and ~10 kg N ha⁻¹ year⁻¹, respectively, result in enhanced mobilization of nitrate. High nitrate concentrations and drainage water loss rates up to 22 kg N ha⁻¹ year⁻¹ have also been found near Tokyo. Although atmospheric deposition may explain a substantial portion of the spatial pattern of nitrate in surface waters, other factors also play major roles in affecting the spatial patterns of nitrogen biogeochemistry. Calcium availability influences the composition of the vegetation and the biogeochemistry of nitrogen. The abundance of sugar maple is directly linked to soil organic matter characteristics and high rates of nitrogen mineralization and nitrification. Seasonal patterns of nitrate concentration and drainage water losses are closely coupled with differences in seasonal temperature and hydrological regimes. Snow-dominated forested catchments have highest nitrate losses during snowmelt. Watersheds in the main island of Japan (Honshu) with high summer temperatures and precipitation inputs have greatest losses of nitrate occur during the late summer. Understanding future changes in nitrate concentrations in surface waters will require an integrated approach that will evaluate concomitantly the influence of both biotic and biotic factors on nitrogen biogeochemistry.  相似文献