Peroxidase-mediated virucidal systems

Peroxidase (myeloperoxidase or lactoperoxidase), hydrogen peroxide, and a halide such as iodide, bromide, or chloride form a potent virucidal system that is effective against polio and vaccinia viruis, particularly at a low pH. The peroxidase-halide-hydrogen peroxide system may contribute to the host defense against certain viral infections.     

Shaping the vertebrate body plan by polarized embryonic cell movements

Polarized cell movements shape the major features of the vertebrate body plan during development. The head-to-tail body axis of vertebrates is elongated in embryonic stages by "convergent extension" tissue movements. During these movements cells intercalate between one another transverse to the elongating body axis to form a narrower, longer array. Recent discoveries show that these polarized cell movements are controlled by homologs of genes that control the polarity of epithelial cells in the developing wing and eye of the fruit fly, Drosophila.     

Antigen-specific proliferation and activation of peripheral blood mononuclear cells from Mycobacterium bovis-infected reindeer

To evaluate antigen-specific proliferative and activation-associated responses from Mycobacterium bovis-infected reindeer, blood mononuclear cells from M. bovis- (n = 10) and non-infected reindeer (n = 4) were stimulated with a recombinant early secretory antigenic target-6 and culture filtrate protein-10 fusion protein (rESAT6:CFP10), M. bovis purified protein derivative, pokeweed mitogen, or medium alone and evaluated by flow cytometry using dye tracker analysis and cell surface marker staining. gammadelta TCR+ and CD8+ cells, but not CD4+ cells, from M. bovis-infected reindeer proliferated in response to specific antigen stimulation. Expression (i.e., mean fluorescence intensity) of CD44 was increased and CD62L decreased on proliferative as compared to non-proliferative fractions in antigen- and mitogen-stimulated cultures. In response rESAT6:CFP10 stimulation, MHC II fluorescence intensity was increased on CD4+, gammadelta TCR+, CD172a+, and IgM+ cells from infected reindeer as compared to that of non-stimulated cells from the same reindeer. Recombinant ESAT6:CFP10 stimulation also induced expansion of a CD172a+, MHC II+ population within mononuclear cell cultures from M. bovis-infected reindeer. Despite a moderate challenge dose and extended duration of incubation, experimental infection of reindeer was generally limited to lymph nodes draining the inoculation site, suggestive of host resistance to progressive disease. Present in vitro findings, therefore, may be predictive of host responses by reindeer that limit progression to disseminated disease.     

Effects of Population Density and Feeding Rate on Growth and Feed Consumption of Red Swamp Crawfish Procambarns clarkii

Wire-mesh enclosures were used in production ponds to conduct growth trials in which population density and feeding rate were evaluated in a 2 × 2 factorial arrangement for their effects on crawfish growth. Juvenile Procambarus clarkii of uniform size (0.5 g) were stocked at 2 or 20 animals/m² in experiment 1 and weighed biweekly for 12 wk. Rice forage served as the detrital base, and supplemental feed (25% crude protein) was provided at either a low (26–52 kg/ha per week) or high (104–418 kg/ha per week) rate. In experiment 2, mixed sizes of crawfish were stocked at 10/m² or 20/m² and fed the formulated feed at either 52 or 312 kg/ha per week. Feed consumption was estimated for each treatment combination. Only population density significantly affected crawfish growth. Mean weight gain and final weights were inversely proportional to density but only when total crawfish biomass exceeded 1,235 kg/ha. Growth was not significantly influenced by feeding rate, but the high feeding rate resulted in a significantly greater ratio of hepatopancreas weight to body weight and tended to decrease hepatopancreas moisture levels, indicating improved condition. Population density, feeding rate, and their interaction had significant effects on estimated feed consumption. From the simple linear regression of mean feed consumption on crawfish standing crop, it was estimated that crawfish consume about 0.1 kg of dry feed per ha per week per kg of crawfish biomass on a 5 d per week feeding schedule at mean water temperatures, ranging from 14 to 30 C.     

Remote sensing for agricultural water management and crop yield prediction

Research we have conducted over the past several years relative to agricultural application of remote sensing is reviewed. In addition, new data are presented from recent experiments reported here for the first time.The subjects treated are soil moisture, evaporation, irrigation scheduling, and crop yield estimation. The analyses indicate that we have the technology at hand to successfully integrate remote sensing techniques into agricultural operations designed to enhance production via intelligent water management.Avenues for additional fruitful research are indicated.     

Chronically starved horses: predicting survival, economic, and ethical considerations

Nine of 45 horses subjected to prolonged malnutrition died subsequent to being placed with a responsible caregiver and being provided an appropriate diet. Initial extreme poor body condition score tended to be associated with death, although individual response to refeeding varied. The financial costs of stabilizing the group of horses significantly exceeded their free market price. Responsible management of chronically starved commercial animals should include options for immediate euthanasia.     

Radio Tracking of a Fin Whale (Balaenoptera physalus)

A tagged whale of the genus Balaenoptera was intermittently tracked by radio for 27.8 hours over a distance of about 145 kilometers. Data on breathing and movement show that during that time the whale took 58 breaths in 130 minutes and traveled 20 kilometers at more than 9 kilometers per hour. Precise measurements of such parameters and of other features of the life history of great whales, which travel long distances over the high seas, often in groups, are now possible through radio tagging.