Bactericidal activity of standard bovine serum against coliform bacteria isolated from udders and the environment of dairy cows.     

E J Carroll  D E Jasper 《American journal of veterinary research》1977,38(12):2019-2022

Coliform organisms were isolated from bedding, udders of cows exhibiting acute or chronic mastitis, and milk of cows tested for udder pathogens. The bactericidal activity of standard bovine serum was tested on 362 isolates, of which 2.4% were killed at a serum dilution of less than 1:5; 2.7% were killed at a dilution of 1.5; 3.0% were killed at a dilution of 1:12.5; and 4.4% were sensitive to a dilution of 1:25. Organisms isolated from mastitic udders were not killed by serum. Sensitivity to agglutination in 1:500 solution of acriflavine was tested on 157 isolates, and only 54 had any degree of agglutination. Of these 54, only 4 organisms had any susceptibility to killing by serum. Results suggest that most organisms in the environment of the cow are resistant to serum, few serum-sensitive coliforms cause mastitis, and agglutination in acriflavine (indicating organisms in the rough phase) does not correlate with sensitibity to serum.  相似文献   

Ultrastructure of Mycoplasma from bovine mastitis as observed in vitro and in vivo   总被引：1，自引：0，他引：1  

D E Jasper  K K Sekhri  V P Eroschenko  N C Jain  J D Dellinger 《American journal of veterinary research》1969,30(4):521-531

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Revenues,expenses, and returns on resources for private veterinary practices in the United States, 1999 and 2001     

Wise JK  Shepherd AJ  Fanning J 《Journal of the American Veterinary Medical Association》2003,223(2):193-195

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GC-FID- and acyl carbon number-based determination of characteristic groupings of complex triglyceride (Benefat S and other) mixtures     

Jasper JP 《Journal of agricultural and food chemistry》2000,48(3):785-791

Techniques for the gas and liquid chromatographic separation of complex mixtures of triglycerides have evolved over the past two decades, as reviewed in detail by Huang et al. (J. Agric. Food Chem. 1995, 43, 1834-1844; J. Agric. Food Chem. 1997, 45, 1770-1778). A novel method for the quantitative partitioning of complex mixtures of triglycerides into functionally related groups is developed and applied to a low-calorie triglyceride mixture [namely, Benefat S or Salatrim plus mid-chain (C(6,8,10,12)) fatty acids]. The method is based on a nonlinear calibration of retention times (RTs) of a suite of standard triglycerides on their acyl carbon numbers [(ACNs), the sum of all the acyl carbon atoms in a given triglyceride] to estimate all of the intermediate ACNs (from 6 to 66). With the calibrated ACN scale and identifications of some components of a complex mixture's composition, ACN-based partitions were established and a Benefat S-triglyceride chromatogram was partitioned into seven functionally related groups. This method is provisional in the sense that it would typically be employed when the identifications of many components of a complex, homologous series were unknown, yet functionally related groups needed to be quantified. This method has proven to be particularly useful in the intercalibration of research laboratories with production facility laboratories during complex ( approximately 50-90 compounds) and large-scale ( approximately 20 ton) syntheses because of the high reproducibility of the ACN-based partitioning of complex chromatograms. This carbon number and statistically based method can be generally applicable to other complex mixtures of organic compounds and is readily adaptable to laboratory intercalibration efforts.  相似文献   

Learning in context through conflict and alignment: Farmers and scientists in search of sustainable agriculture   总被引：1，自引：0，他引：1  

Jasper?EshuisEmail author  Marian?Stuiver 《Agriculture and Human Values》2005,22(2):137-148

This article analyzes learning in context through the prism of a sustainable dairy-farming project. The research was performed within a nutrient management project that involved the participation of farmers and scientists. Differences between heterogeneous forms of farmers knowledge and scientific knowledge were discursively constructed during conflict and subsequent alignment over the validity and relevance of knowledge. Both conflict and alignment appeared to be essential for learning in context. Conflict spurred learning when disagreeing groups of actors developed their knowledge in order to strengthen their arguments. Conflict caused self-referentiality when the actors no longer listened to each other. This inhibited self-reflection, thus blocking ongoing learning. Nevertheless, after a period of alignment, scientific models and knowledge of farmers were reevaluated and recontextualized. Through determining how to use scientific models and farmers knowledge for further learning, aimed at a shared goal, the participating actors also learned how to learn.Jasper Eshuis is a PhD candidate in the Department of Communication Management at Wageningen University, The Netherlands. His research deals with multiple land use, governance processes, and farmers decision-making. He is currently interested in monitoring and trust.Marian Stuiver is a PhD candidate in the Department of Rural Sociology of Wageningen University, The Netherlands. Her current research focuses on nutrient management, farmers innovation, and co-production of knowledge within the agricultural sciences.  相似文献   

Competencies: a cure for pre-med curriculum     

Anderson WA  Amasino RM  Ares M  Banerjee U  Bartel B  Corces VG  Drennan CL  Elgin SC  Epstein IR  Fanning E  Guillette LJ  Handelsman J  Hatfull GF  Hoy RR  Kelley D  Leinwand LA  Losick R  Lu Y  Lynn DG  Neuhauser C  O'Dowd DK  Olivera T  Pevzner P  Richards-Kortum RR  Rine J  Sah RL  Strobel SA  Walker GC  Walt DR  Warner IM  Wessler S  Willard HF  Zare RN 《Science (New York, N.Y.)》2011,334(6057):760-761

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Soil‐ and plant‐based nitrogen‐fertilizer recommendations in arable farming     

Hans‐Werner Olfs  Klaus Blankenau  Frank Brentrup  Jrg Jasper  Axel Link  Joachim Lammel 《植物养料与土壤学杂志》2005,168(4):414-431

Under‐ as well as overfertilization with nitrogen (N) will result in economic loss for the farmer due to reduced yields and quality of the products. Also from an ecological perspective, it is important that the grower makes the correct decision on how much and when to apply N for a certain crop to minimize impacts on the environment. To aggravate the situation, N is a substance that is present in many compartments in different forms (nitrate, ammonium, organic N, etc.) in the soil‐plant environment and takes part in various processes (e.g., mineralization, immobilization, leaching, denitrification, etc.). Today, many N‐recommendation systems are mainly based on yield expectation. However, yields are not stable from year to year for a given field. Also the processes that determine the N supply from other sources than fertilizer are not predictable at the start of the growing season. Different methodological approaches are reviewed that have been introduced to improve N‐fertilizer recommendations for arable crops. Many soil‐based methods have been developed to measure soil mineral N (SMN) that is available for plants at a given sampling date. Soil sampling at the start of the growing period and analyzing for the amount of NO ‐N (and NH ‐N) is a widespread approach in Europe and North America. Based on data from field calibrations, the SMN pool is filled up with fertilizer N to a recommended amount. Depending on pre‐crop, use of organic manure, or soil characteristics, the recommendation might be modified (±10–50 kg N ha^–1). Another set of soil methods has been established to estimate the amount of N that is mineralized from soil organic matter, plant residues, and/or organic manure. From the huge range of methods proposed so far, simple mild extraction procedures have gained most interest, but introduction into practical recommendation schemes has been rather limited. Plant‐analytical procedures cover the whole range from quantitative laboratory analysis to semiquantitative “quick” tests carried out in the field. The main idea is that the plant itself is the best indicator for the N supply from any source within the growth period. In‐field methods like the nitrate plant sap/petiole test and chlorophyll measurements with hand‐held devices or via remote sensing are regarded as most promising, because with these methods an adequate adjustment of the N‐fertilizer application strategy within the season is feasible. Prerequisite is a fertilization strategy that is based on several N applications and not on a one‐go approach.  相似文献   

The use of the log-linear model to evaluate the effects of three herd factors on Streptococcus agalactiae mastitis occurrence in California, 1977     

Margaret A. Thorburn  Tim E. Carpenter  Donald E. Jasper  Chester B. Thomas 《Preventive veterinary medicine》1983,1(3):243-256

Epidemiologic relationships among Streptococcus agalactiae infected dairy herds and herd size, location and California Dairy Herd Improvement Association (CDHIA) participation were examined using log-linear methodology. Dairies located in five out of the six California Bureau of Animal Health veterinary districts were studied. Data sources included the Dairy Cattle Data Base, which uniquely identifies each of the 2875 dairies in California, the 1977 statewide CDHIA year-end summary report and microbiological results from a 1977 statewide survey of bulk tank milk samples. These data were merged, fitted and the best model selected using likelihood-ratio statistics. The model included all four “main effects”, the six possible “1st-order effetss” and the “2nd-order effect” due to the interaction of herd size, location and CDHIA participation. Subsequently, a logit model was used to estimate the effect of the independent herd factor variables (size, location and CDHIA participation) on the log odds of the dependent S. agalactiae variable. This model required conditioning on the three-way relationship among the independent variables.medium-sized, non-CDHIA herds in district 2 (northcentral California) showed the highest expected odds (3.37) for S. agalactiae in bulk tank milk, while small, CDHIA herds in district 3 (northcentral coastal California) produced the lowest odds (0.39).  相似文献   

Relationship between mastitis pathogen numbers in bulk tank milk and bovine udder infections in California dairy herds   总被引：1，自引：0，他引：1  

R N Gonzalez  D E Jasper  R B Bushnell  T B Farver 《Journal of the American Veterinary Medical Association》1986,189(4):442-445

Samples of bulk tank milk and cow-composite milk from 23,138 dairy cows from 50 California dairies were examined by use of microbiologic procedures. The number of colonies of mastitis pathogens isolated per milliliter of bulk tank milk (used as a predictor of the percentage of infected cows in the herd) was evaluated, using simple regression analysis and Spearman's rank correlation. Correlations between the pathogens and the percentage of cows in each herd shedding the pathogens were found for Streptococcus agalactiae (r = 0.71) and mycoplasma (r = 0.59), but were considerably lower for other pathogens. When greater than or equal to 4,000 colonies of Streptococcus agalactiae were found per milliliter of bulk tank milk, at least 7% of the cows in the herd was shedding this organism. However, a pattern was not found between the number of mycoplasma colonies per milliliter of bulk tank milk and the percentage of infected cows in the herd.  相似文献   

Enterobacteriaceae bedding populations,rainfall and mastitis on a california dairy     

C.B. Thomas  D.E. Jasper  M.H. Rollins  R.B. Bushnell  E.J. Carroll 《Preventive veterinary medicine》1983,1(3):227-242

The bedding populations of Enterobacteriaceae, rainfall and mastitis incidence due to Enterobacteriaceae were studied over 12 months on one California dairy. The bedding material used was a mixture of sawdust and wood shavings. Over the 12-month period Escherichia coli was isolated from 59 mastitic milk samples and Klebsiella pneumoniae from 44. The bedding population, rainfall and mastitis incidence data were analyzed by fitting log-linear models. The results of these analyses indicated that rainfall, bedding populations of E. coli and E. coli mastitis incidence were statistically independent, while a strong association existed between rainfall and K. pneumoniae bedding populations and separately between K. pneumoniae bedding populations and the incidence of K. pneumoniae mastitis.  相似文献