Isolation ofSalmonella from meat and meat products in Botswana     

I. T. Ndzinge  Mary L. M. Hall  R. G. Mares 《Tropical animal health and production》1982,14(2):89-90

  相似文献   

Biochemical evaluation of mitochondrial respiratory chain enzymes in canine skeletal muscle     

Wakshlag JJ  Cooper BJ  Wakshlag RR  Kallfelz FA  Barr SC  Nydam DV  Dimauro S 《American journal of veterinary research》2004,65(4):480-484

OBJECTIVE: To perform respiratory chain enzymatic activity assays on canine skeletal muscle biopsy specimens and establish reference range values of skeletal muscle enzyme activities for dogs. SAMPLE POPULATION: Biopsy specimens from the vastus lateralis muscle were obtained from 24 dogs (8 sexually intact males and 14 sexually intact females) ranging from 15 months to 6 years of age. PROCEDURE: Mean values of citrate synthase, cytochrome-c oxidase, succinate dehydrogenase, succinate dehydrogenase-cytochrome-c reductase, nicotinamide adenine dinucleotide (NADH) dehydrogenase, and NADH dehydrogenase-cytochrome-c reductase activities were established by use of 6 standard spectrophotometric assays for respiratory chain enzyme analysis. RESULTS: Compared with published data for skeletal muscle enzyme activities in humans, skeletal muscle enzyme activities in dogs were 2- to 4-fold higher. Additionally, citrate synthase activity, a marker for mitochondrial volume, was positively correlated with age in dogs, suggesting that mitochondrial volume increases with age, although no apparent change in respiratory chain enzymatic activity with an increase in age was found. CONCLUSIONS AND CLINICAL RELEVANCE: Reference range values for skeletal muscle enzyme activities of dogs are needed to accurately interpret results of respiratory chain enzymatic activity assays. During investigation of metabolic myopathies, if skeletal muscle biopsy specimens are evaluated for respiratory chain enzyme kinetics, they should be performed and evaluated in concert with skeletal muscle biopsy specimens from clinically normal animals of the same species.  相似文献   

Use of the caudolateral curvilinear osteophyte as an early marker for future development of osteoarthritis associated with hip dysplasia in dogs     

Powers MY  Biery DN  Lawler DE  Evans RH  Shofer FS  Mayhew P  Gregor TP  Kealy RD  Smith GK 《Journal of the American Veterinary Medical Association》2004,225(2):233-237

OBJECTIVE: To determine the relationship between the caudolateral curvilinear osteophyte (CCO) and osteoarthritis associated with hip dysplasia in dogs. DESIGN: Longitudinal cohort study. ANIMALS: 48 Labrador Retrievers from 7 litters. PROCEDURE: In each of 24 sex- and size-matched pairs fed the same diet, a restricted-fed dog was fed 25% less than a control dog for life. The dogs' hips were evaluated in the standard ventrodorsal hip-extended radiographic projection at 16, 30, and 52 weeks of age and then yearly for life. Histologic examination of hip joint tissues was performed on 45 dogs. RESULTS: Median age at death was 11.2 years. Adjusting for feeding group, dogs with a CCO were 3.7 times as likely to develop radiographic signs of osteoarthritis than those without a CCO. Stratified by diet, 100% of the control dogs with a CCO developed radiographic signs of osteoarthritis and 55% of restricted-fed dogs with a CCO developed radiographic signs of osteoarthritis. The CCO was the first radiographic change seen in 22 of 29 (76%) dogs with osteoarthritis. Overall, 35 of 37 (95%) dogs with a CCO had histopathologic lesions of osteoarthritis. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate a relationship between a CCO on the femoral neck and subsequent development of radiographic signs of osteoarthritis in Labrador Retrievers evaluated over their life span. A CCO is an important early radiographic indication of osteoarthritis associated with canine hip dysplasia.  相似文献   

Detection of bacterial wilt infection caused by Ralstonia solanacearum in potato (Solanum tuberosum L.) through multifractal analysis applied to remotely sensed data     

Perla Chávez  Christian Yarlequé  Hildo Loayza  Víctor Mares  Paola Hancco  Sylvie Priou  María del Pilar Márquez  Adolfo Posadas  Percy Zorogastúa  Jaume Flexas  Roberto Quiroz 《Precision Agriculture》2012,13(2):236-255

Potato bacterial wilt, caused by the bacterium Ralstonia solanacearum race 3 biovar 2 (R3bv2), affects potato production in several regions in the world. The disease becomes visually detectable when extensive damage to the crop has already occurred. Two greenhouse experiments were conducted to test the capability of a remote sensing diagnostic method supported by multispectral and multifractal analyses of the light reflectance signal, to detect physiological and morphological changes in plants caused by the infection. The analysis was carried out using the Wavelet Transform Modulus Maxima (WTMM) combined with the Multifractal (MF) analysis to assess the variability of high-resolution temporal and spatial signals and the conservative properties of the processes across temporal and spatial scales. The multispectral signal, enhanced by multifractal analysis, detected both symptomatic and latently infected plants, matching the results of ELISA laboratory assessment in 100 and 82%, respectively. Although the multispectral method provided no earlier detection than the visual assessment on symptomatic plants, the former was able to detect asymptomatic latent infection, showing a great potential as a monitoring tool for the control of bacterial wilt in potato crops. Applied to precision agriculture, this capability of the remote sensing diagnostic methodology would provide a more efficient control of the disease through an early and full spatial assessment of the health status of the crop and the prevention of spreading the disease.  相似文献   

Food sovereignty in US food movements: radical visions and neoliberal constraints     

Alison Hope Alkon  Teresa Marie Mares 《Agriculture and Human Values》2012,29(3):347-359

Although the concept of food sovereignty is rooted in International Peasant Movements across the global south, activists have recently called for the adoption of this framework among low-income communities of color in the urban United States. This paper investigates on-the-ground processes through which food sovereignty articulates with the work of food justice and community food security activists in Oakland, California, and Seattle, Washington. In Oakland, we analyze a farmers market that seeks to connect black farmers to low-income consumers. In Seattle, we attend to the experiences of displaced immigrant farmers from Latin America and their efforts to address their food needs following migration. In both cases, we find that US based projects were constrained by broader forces of neoliberalism that remained unrecognized by local activists. In Oakland, despite a desire to create a local food system led by marginalized African Americans, emphasis on providing green jobs in agriculture led activists to take a market-based approach that kept local food out of the economic grasp of food-insecure neighborhood residents. In Seattle, the marginalization of the immense agroecological knowledge of Latino/an immigrant farmers rendered local food projects less inclusive and capable of transformative change. Taken together, these very different cases suggest that a shift towards food sovereignty necessitates a broad acknowledgement of and resistance to neoliberalism.  相似文献   

Effect of temperature on lutein esterification and lutein stability in wheat grain     

Fauziah Tufail Ahmad  Robert E. Asenstorfer  Imelda R. Soriano  Daryl J. Mares 《Journal of Cereal Science》2013

The creamy colour of many wheat-based end-products is conferred by endogenous lutein. During post-harvest storage of grain, free lutein may be converted in part to potentially more stable lutein mono- and di-fatty acid esters. This study investigates the synthesis of lutein esters and stability of free lutein and lutein esters over a wide range of temperatures in grain of a high lutein bread wheat, Triticum aestivum L. line DM5685*B12 and a durum, Triticum durum L cv Kamilaroi. Disappearance of free lutein and lutein esterification followed first order reaction rates. The maximum rate of lutein esterification was at ≈80 °C, however, the optimum temperature for maximum synthesis with minimum degradation was between 30 °C and 60 °C. No ester synthesis was observed at temperatures higher than 120 °C. The data are consistent with an enzyme participating in the esterification reaction. Lutein esters were found to be more stable than free lutein with a longer shelf life at 60 °C whilst at temperatures ≤40 °C, lutein degradation was minimal. This study provides new information on lutein ester formation and lutein stability that should be useful to grain handlers and food manufacturers seeking to optimise retention of lutein for the benefit of consumers.  相似文献   

The risk and control of Salmonella outbreaks in calf-raising operations: a mathematical modeling approach     

Lanzas C  Warnick LD  Ivanek R  Ayscue P  Nydam DV  Gröhn YT 《Veterinary research》2008,39(6):61

Salmonellosis in calves has economic and welfare implications, and serves as a potential source of human infections. Our objectives were to assess the risk of Salmonella spread following its introduction into a herd of pre-weaned calves and to evaluate the efficacy of control strategies to prevent and control outbreaks. To meet these objectives, we developed a model of Salmonella transmission within a pre-weaned group of calves based on a well documented outbreak of salmonellosis in a calf-raising operation and other literature. Intervention scenarios were evaluated in both deterministic and stochastic versions of the model. While the basic reproduction number (R0) was estimated to be 2.4, simulation analysis showed that more than 60% of the invasions failed after the introduction of a single index case. With repeated introduction of index cases, the probability of Salmonella spread was close to 1, and the tested control strategies were insufficient to prevent transmission within the group. The most effective strategies to control ongoing outbreaks were to completely close the rearing operation to incoming calves, to increase the proportion of admitted calves that were immunized (>75%), and to assign personnel and equipment to groups of calves.  相似文献   

Calf-level risk factors for neonatal diarrhea and shedding of Cryptosporidium parvum in Ontario dairy calves     

Trotz-Williams LA  Wayne Martin S  Leslie KE  Duffield T  Nydam DV  Peregrine AS 《Preventive veterinary medicine》2007,82(1-2):12-28

This work was conducted to investigate calf-level factors that influence the risk of neonatal diarrhea and shedding of Cryptosporidium parvum oocysts in calves, on dairy farms in Ontario with histories of calf diarrhea or cryptosporidiosis. Fecal samples were collected weekly for 4 weeks from each of 1045 calves under 30 days of age on 11 dairy farms in south-western Ontario during the summer of 2003 and the winter of 2004. A questionnaire designed to gather information on calf-level management factors was administered on farm for each calf in the study. Samples were examined for C. parvum oocysts by microscopy, and a subset of specimens was also tested for enterotoxigenic Escherichia coli, Salmonella, bovine rotavirus and bovine coronavirus. The consistency of each sample was scored and recorded at the time of collection in order to assess the presence or absence of diarrhea. In addition, a blood sample was taken from each calf upon enrollment in the study, for assessment of maternal antibody transfer and for polymerase chain reaction testing for persistent bovine viral diarrhea virus infection. Using the GLLAMM function in Stata 9.0, multilevel regression techniques were employed to investigate associations between management practices and the risk of C. parvum shedding or diarrhea. C. parvum oocysts were detected in the feces of 78% of the 919 calves from which all four fecal samples had been collected. Furthermore, 73% of the 846 calves for which all four fecal consistency scores had been recorded were diarrheic at the time of collection of at least one sample. Significant predictors of the calf-level risk of C. parvum shedding included the use of calf diarrhea prophylaxis in pregnant cows, and the type of maternity facilities in which the calves were born. Factors associated with an increased risk of diarrhea were leaving the calf with the dam for more than an hour after birth, and the birth of a calf in the summer as opposed to winter. Calves shedding C. parvum oocysts had 5.3 (95% CI 4.4, 6.4) times the odds of diarrhea than non-shedding calves, controlling for other factors included in the final multivariable model. Furthermore, infected calves shedding more than 2.2 x 10(5) oocysts per gram of feces were more likely to scour than infected calves shedding lower numbers of oocysts (OR= 6.1, 95% CI 4.8, 7.8). The odds of diarrhea in calves shedding oocysts that had been allowed to remain with their dams for more than an hour were higher than the odds of diarrhea in shedding calves that had been separated from their dams within an hour after birth.  相似文献   

Evaluation of polymerase chain reaction diagnosis of Cryptosporidium spp in dairy cattle and wildlife     

Ziegler PE  Santucci F  Lindergard G  Nydam DV  Wade SE  Schaaf SL  Chang YF  Mohammed HO 《Veterinary therapeutics : research in applied veterinary medicine》2007,8(2):148-159

This study investigated the utility of the polymerase chain reaction (PCR) protocol as a screening test for Cryptosporidium spp in 125 fecal samples from dairy cattle and wild rodents. Samples initially examined by fecal flotation and ELISA were evaluated using four PCR protocols (18S SSU rRNA, TRAP-C2, HSP70, and COWP), and the relative accuracy and agreement of PCR protocols was assessed. Although PCR can be both highly sensitive and accurate, the ability of these protocols to accurately detect DNA in samples can vary. A combination of techniques may be the best choice for to screen samples for this parasite.  相似文献   

Changes in the nutritional parameters of muscles of the common carp (Cyprinus carpio) and the silver carp (Hypophthalmichthys molitrix) following environmental exposure to cyanobacterial water bloom     

Jan Mares  Miroslava Palikova  Radovan Kopp  Stanislav Navratil  & Jiri Pikula 《Aquaculture Research》2009,40(2):148-156

The present study evaluated the effect of naturally developing cyanobacteria on the composition of muscles of two commercially important freshwater fish species. Fish were exposed to cyanobacterial biomass including Microcystis aeruginosa and Microcystis ichthyoblabe for 4 weeks. Then, they were transferred to dechlorinated potable water without any cyanobacteria for another 4-week period, thus modelling their preparation for consumers. Samples of muscles were collected every week during exposure and subsequent stay in dechlorinated potable water. The cyanobacterial water bloom of 3.9–6 × 10⁵ cells mL⁻¹ (133–383 μg g⁻¹ of total MC DW) induced statistically significant effects only in the content of fatty acids ( P <0.05; P <0.01) in the common carp ( Cyprinus carpio ), while all studied parameters including the content of dry matter and fat ( P <0.01), proteins ( P <0.05), fatty acid composition ( P <0.05; P <0.01) and some amino acids ( P <0.05) were affected in the silver carp ( Hypophthalmichthys molitrix ). This study has shown that cyanobacteria in the environment of commercially produced fish may decrease the dietetic value of fish muscles.  相似文献