Vulnerabilities and fisheries impacts: the uncertain future of manta and devil rays

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The effects of storage temperature on goat milk somatic cell count using the DeLaval counter

This study investigated the influence of storage temperature and storage time on goat milk somatic cell counts (SCCs) determined using the DeLaval cell counter (DCC). SCCs were measured in 40 Majorera goat milk samples using the DCC device. Samples were grouped from high score (>2,750 × 10³ cells/mL) to low score (<630 × 10³ cell/mL) according to the SCC. Each milk sample was divided into four aliquots and stored at four different temperatures (4°C, 21°C, 36°C or 45°C). The SCC was recorded every hour for 12 hours. Storage of goat milk with a high SCC for 5, 5, 2 or 1 hour at 4°C, 21°C, 36°C or 45°C, respectively, decreased the SCC value compared to fresh milk. The goat milk SCC was lower after 1 hour of storage than that determined for fresh milk at any tested temperature in low-SCC samples. The data presented herein suggest that regardless of storage temperature, goat milk samples should not be stored for more than 1 hour before measurement of SCC with a DCC device.     

Direct exchange of electrons within aggregates of an evolved syntrophic coculture of anaerobic bacteria

Microbial consortia that cooperatively exchange electrons play a key role in the anaerobic processing of organic matter. Interspecies hydrogen transfer is a well-documented strategy for electron exchange in dispersed laboratory cultures, but cooperative partners in natural environments often form multispecies aggregates. We found that laboratory evolution of a coculture of Geobacter metallireducens and Geobacter sulfurreducens metabolizing ethanol favored the formation of aggregates that were electrically conductive. Sequencing aggregate DNA revealed selection for a mutation that enhances the production of a c-type cytochrome involved in extracellular electron transfer and accelerates the formation of aggregates. Aggregate formation was also much faster in mutants that were deficient in interspecies hydrogen transfer, further suggesting direct interspecies electron transfer.     

Determining the shade tolerance of American chestnut using morphological and physiological leaf parameters

American chestnut (Castanea dentata (Marsh.) Borkh.) was once a principal component of the eastern deciduous forest until it became functionally extinct as a result of the invasive fungus Cryphonectria parasitica (Murr.) Barr. Restoration efforts are underway by means of a blight-resistant American-Chinese chestnut hybrid, and detailed silvicultural information, such as the shade tolerance of American chestnut and optimum site selection for restoration, is critical for planting success. In the present study, the physiological and morphological leaf characteristics of pure American chestnut seedlings, saplings, and mature trees were investigated in one of the few remaining stands of oak-chestnut vegetation (West Salem, WI) to determine shade tolerance. Seedlings, saplings, and mature trees had high maximum rates of photosynthesis, similar to shade intolerant species, and low light compensation points (LCPs), quantum efficiency, leaf mass per area (LMA), and percent nitrogen content, reminiscent of shade tolerant species. Dark respiration rates of seedlings and saplings were low, but increased in mature trees. LMA was found to significantly increase with height in the canopy, indicating a high level of light-induced plasticity. The results of this study suggest that American chestnut should be classified as intermediate in shade tolerance.     

Use of the ADVIA 120 for differentiating extracellular and intracellular hemoglobin

BACKGROUND: The use of cell-free hemoglobin (Hgb) solutions, such as Oxyglobin (Biopure Corp, Cambridge, MA, USA), as a blood substitute for the treatment of acute anemias is increasing in veterinary medicine. These solutions interfere with colorimetric tests, which do not discriminate between cellular Hgb (Hgb-cell) from the patient and extracellular Hgb (Hgb-delta) from the Oxyglobin, and therefore make the monitoring of anemia, based on Hgb concentration, difficult. The ADVIA 120 hematology analyzer (Bayer Diagnostics, Tarrytown, NY, USA) evaluates Hgb by 2 methods, a standard cyanmethemoglobin colorimetric method and flow cytometry, and therefore might provide the means to differentiate extracellular and intracellular Hgb. OBJECTIVE: The objective of this study was to determine the accuracy and precision of the ADVIA 120 in differentiating extracellular from intracellular Hgb. METHODS: Anticoagulated whole blood samples from 10 healthy dogs were analyzed in triplicate on the ADVIA 120. Hgb-delta concentration was determined by adding Oxyglobin (13 g/dL) to the whole blood samples at dilutions of 1:1, 1:2, 1:4, 1:8, 1:16, and 1:32. Hgb-cell and Hgb-total values were calculated and compared with actual values by linear regression. Analyses were done in triplicate and repeated 9 consecutive times to evaluate intra-assay precision of Hgb-total and Hgb-cell determinations. RESULTS: Correlation between Hgb values obtained by colorimetric (Hb-total) and flow cytometric (Hgb-cell) methods on whole blood samples was high (R(2) = .99; n = 10) with a slope of 0.96 and intercept of 0. Correlation between actual and predicted Hgb-cell values also was high (R(2) = .99), with a small positive bias (0.289 +/- 0.185; n = 60). Intra-assay precisions were high, with most coefficients of variation <2%. CONCLUSION: The ADVIA 120 is capable of differentiating Hgb-cell from Hgb-delta. The flow cytometric method is accurate and precise when compared with the cyanmethemoglobin method. A small bias between the results is unlikely to be clinically significant but may affect the ability of the ADVIA to differentiate small quantities (<0.3 g/dL) of Hgb-delta.     

Pre- and postoperative radiographic and computed tomographic evaluation of dogs with medial patellar luxation

OBJECTIVE: To quantify, using radiographic and computed tomographic (CT) techniques, the effects of surgical procedures most commonly combined to treat dogs with medial patellar luxation (MPL). STUDY DESIGN: Prospective study. METHODS: Six dogs with 8 MPL were studied. Radiographs and CT of the pelvic limbs were obtained before and immediately after soft-tissue reconstruction, trochlear wedge recession, and tibial crest transposition. Radiographic measurements included angle of inclination, Norberg angle, quadriceps angle (QA), anteversion angle, ratio of the length of the patellar tendon (PT) to the length of the patella, and change in patella tendon angle. CT measurements included angle of inclination, Norberg angle, QA, anteversion angle, depth of the femoral trochlear groove, ratio of the middle femoral trochlear groove depth to the patella thickness, and tibial crest alignment. RESULTS: Conformation of the coxofemoral joint was not affected by surgery. Surgical treatment corrected the QA by 33-58%. Trochlear wedge recession was most effective in deepening the proximal trochlea by 103.5%. The ratio of the middle femoral trochlear groove depth to the thickness of the patella postoperatively resulted in 50% coverage of the patella. Tibial crest transposition resulted in caudalization of the PT by 8.5+/-3.0 degrees, with lateralization of the tibial tuberosity of 11.3 degrees. CONCLUSION: The effects of surgery for MPL can be quantified with radiographic and CT measurements. Surgical correction restored the alignment of the quadriceps and adequately deepened the femoral trochlear groove. Tibial crest transposition resulted in caudalization of the patella tendon and lateralization of the tibial tuberosity. CLINICAL RELEVANCE: These pilot data quantified the effects of surgical procedures most commonly combined to treat MPL. We hope to use these measurements to correlate surgical treatment with functional outcome and postoperative occurrence of luxation.     

Molecular analyses of disease pathogenesis: application of bovine microarrays

The molecular analysis of disease pathogenesis in cattle has been limited by the lack of availability of tools to analyze both host and pathogen responses. These limitations are disappearing with the advent of methodologies such as microarrays that facilitate rapid characterization of global gene expression at the level of individual cells and tissues. The present review focuses on the use of microarray technologies to investigate the functional pathogenomics of infectious disease in cattle. We discuss a number of unique issues that must be addressed when designing both in vitro and in vivo model systems to analyze host responses to a specific pathogen. Furthermore, comparative functional genomic strategies are discussed that can be used to address questions regarding host responses that are either common to a variety of pathogens or unique to individual pathogens. These strategies can also be applied to investigations of cell signaling pathways and the analyses of innate immune responses. Microarray analyses of both host and pathogen responses hold substantial promise for the generation of databases that can be used in the future to address a wide variety of questions. A critical component limiting these comparative analyses will be the quality of the databases and the complete functional annotation of the bovine genome. These limitations are discussed with an indication of future developments that will accelerate the validation of data generated when completing a molecular characterization of disease pathogenesis in cattle.     

Herbicide loss following application to a railway

Railways have been identified as a potential source of herbicides detected in surface and groundwaters, but there are few data to support this theory. Two studies were undertaken to investigate the fate of herbicides applied to railway trackbeds: a pilot study in a section of a disused, but intact, cutting where runoff and throughflow were sampled from trenches adjacent to the treated area, and a larger scale study on 0.75 km of embankment where surface water from the drainage ditch at the base of the embankment and groundwater were sampled. In the pilot study, peak concentrations of atrazine, diuron and glyphosate (1280, 210 and 15 microg litre(-1) respectively) were detected 6days after treatment (DAT). Oxadiazon, oryzalin and isoxaben were not detected above their limits of quantification. Lower concentrations were detected 81 DAT (10 and 0.8 microg litre(-1) of atrazine and glyphosate respectively). In the larger scale study, herbicides were not detected, in either the surface water or groundwater, at concentrations above the limit of detection that could be attributed to application to the railway. Rainfall volume and depth to sampling point may partly explain the different results obtained from the two studies. The findings are compared with herbicide losses from other 'hard surfaces'.     

Seroprevalence of Mycobacterium avium subsp paratuberculosis infection among dairy cows in Colorado and herd-level risk factors for seropositivity

OBJECTIVE: To estimate seroprevalence of Mycobacterium avium subsp paratuberculosis (MAP) infection among adult dairy cows in Colorado and determine herd-level factors associated with the risk that individual cows would be seropositive. DESIGN: Cross-sectional observational study. ANIMALS: 10,280 adult (> or = 2 years old) dairy cows in 15 herds in Colorado. PROCEDURE: Serum samples were tested with a commercial ELISA. A herd was considered to be infected with MAP if results of mycobacterial culture of > or = 1 individual cow fecal sample were positive or if > or = 1 culled cow had histologic evidence of MAP infection. RESULTS: 424 of the 10,280 (4.12%) cows were seropositive. Within-herd prevalence of seropositive cows ranged from 0% to 7.82% (mean, 2.6%). Infection was confirmed in 11 dairies. Cows in herds that had imported > or = 8% of their current herd size annually during the preceding 5 years were 3.28 times as likely to be seropositive as were cows in herds that imported < 8%. Cows in herds with > or = 600 lactating cows were 3.12 times as likely to be seropositive as were cows in herds with < 600 lactating cows. Cows in herds with a history of clinical signs of MAP infection were 2.27 times as likely to be seropositive as were cows in herds without clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE: Annual importation rate, herd size, and whether cows in the herd had clinical signs typical of MAP infection were associated with the risk that individual cows would be seropositive for MAP infection.     

Unilateral congenital elbow luxation in a Cavalier King Charles Spaniel

A 7-week-old, intact female, Cavalier King Charles Spaniel was evaluated for nonweight bearing lameness of the right forelimb. Type III unilateral congenital elbow luxation was diagnosed radiographically. After surgical reduction, temporary placement of a transarticular pin, and external splinting of the joint, full weight bearing was achieved. Radial head subluxation persisted.