Decision support system for greenhouse seedling production

A decision support system was developed for greenhouse seedling production by incorporating tomato seedling growth models to attain the desired dry weight of tomato seedlings at the time of transplant. Tomato seedlings were produced in a greenhouse to develop growth models, which were divided into emergence, and post emergence. These mathematical models were used to develop a decision making process in the form of a DSS. The DSS was developed in visual basic 6.0. The DSS has two modules long term planning and daily temperature management. The former module deals with the long term planning of seedling production and advice on average temperature and supplementary light depending on users input, while the other module deals with daily temperature management and advice on hour to hour for temperature control strategies as per the prevailing environmental and greenhouse conditions, and required temperature conditions to achieve the predefined target of seedling growth in terms of days required for seedling production. The developed algorithms attempt to maximum use of ambient conditions and minimum use of supplementary expensive energy. The feature not only hardens the seedlings but also reduces the cost of seedlings hardening.     

Moisture storage and transport properties of preservative treated and untreated southern pine wood

Moisture storage and transport properties of southern pine (Pinus spp.) wood were measured for implementation into hygrothermal models. Specimens were untreated or pressure-treated with alkaline copper quaternary (ACQ) preservative. Moisture storage was characterized with sorption isotherms in the hygroscopic region (high capillary pressures) and documented with mercury intrusion porosimetry in the overhygroscopic region (low capillary pressures). The data were then combined into a single moisture retention curve as a function of capillary pressure. Moisture transport was evaluated from steady-state water vapor transmission and dynamic capillary water absorption experiments. These data were used to calculate the moisture permeability over the entire range of capillary pressures using the diffusivity approach of Carmeliet et al. Moisture storage and transport properties were similar for the untreated and ACQ-treated southern pine, except for the permeability of the treated wood which was lower in the radial direction. The data presented here can be used to improve the accuracy of hygrothermal and combined hygrothermal–corrosion modeling simulations.     

An experimental model for subclinical edema disease (Escherichia coli enterotoxemia) manifest as vascular necrosis in pigs.

An experimental model for subclinical edema disease was developed in weanling pigs. In multiple experiments, 3-week-old pigs were weaned, then inoculated intragastrically with 10(10) colony-forming units of an SLT-IIv-positive strain of Escherichia coli originally isolated from a pig with edema disease (principals). Control pigs were inoculated with a nonpathogenic E coli strain. Of 39 principals, 8 developed clinical edema disease within 14 days after inoculation. However, 20 of 21 principals that did not develop clinical signs of edema disease, but were submitted for necropsy examination at 14 days after inoculation, had characteristic vascular lesions of edema disease. Vascular lesions, found principally in ileum and brain, consisted of segmental necrosis of myocytes in the tunica media of small arteries and arterioles. None of the pigs inoculated with a nonpathogenic strain of E coli developed edema disease or vascular lesions. None of the principals necropsied at 2 days after inoculation had vascular lesions. Development of vascular lesions by 14 days after inoculation was used as the end point for detecting subclinical edema disease in the model.     

Role of the posterior vacuole in Spraguea lophii (Microsporidia) spore hatching

Microsporidia constitute a large group of obligate intracellular protozoan parasites that inject themselves into host cells via the extrusion apparatus of the infective spore stage. Although the injection process is poorly understood, its energy source is thought to reside in the posterior vacuole that swells significantly during spore firing. Here we report the presence and localisation of the key peroxisomal enzymes catalase and acyl-CoA oxidase (ACOX) within the posterior vacuole of Spraguea lophii (Doflein, 1898) spores. Western blot analyses show that these enzymes discharge out of the spore and end up in the medium external to the extruded sporoplasms. The presence of a catalase enzyme system in the Microsporidia was first made evident by the detection of significant levels of molecular oxygen in the medium containing discharging spores in the presence of hydrogen peroxide. Catalase was visualised in inactive, activated, and discharged spores using alkaline diaminobenzidine (DAB) on glutaraldehyde-fixed cells. The position of these enzymes within the extrusion apparatus before and during spore discharge support the Lom and Vávra model that postulates discharge occurs by an eversion process. In addition to these enzymes, spores of S. lophii contain another characteristic peroxisomal component, the very long chain fatty acid (VLCFA) nervonic acid. A sizeable decrease in nervonic acid levels occurs during and after spore discharge. These data indicate that nervonic acid is discharged from the spore into the external medium during firing along with the catalase and ACOX enzymes.     

Power of a Labrador Retriever-Greyhound pedigree for linkage analysis of hip dysplasia and osteoarthritis

OBJECTIVE: To estimate the number of dogs required to find linkage to heritable traits of hip dysplasia in dogs from an experimental pedigree. ANIMALS: 147 Labrador Retrievers, Greyhounds, and their crossbreed offspring. PROCEDURE: Labrador Retrievers with hip dysplasia were crossed with unaffected Greyhounds. Age at detection of femoral capital ossification, distraction index (DI), hip joint dorsolateral subluxation (DLS) score, and hip joint osteoarthritis (OA) were recorded. Power to find linkage of a single marker to a quantitative trait locus (QTL) controlling 100% of the variation in a dysplastic trait in the backcross dogs was determined. RESULTS: For the DI at the observed effect size, recombination fraction of 0.05, and heterozygosity of 0.75, 35 dogs in the backcross of the F1 to the Greyhound generation would yield linkage at a power of 0.8. For the DLS score, 35 dogs in the backcross to the Labrador Retriever generation would be required for linkage at the same power. For OSS, 45 dogs in the backcross to the founding Labrador Retrievers would yield linkage at the same power. Fewer dogs were projected to be necessary to find linkage to hip OA. Testing for linkage to the DLS at 4 loci simultaneously, each controlling 25% of the phenotypic variation, yielded an overall power of 0.7 CONCLUSIONS AND CLINICAL SIGNIFICANCE: Based on this conservative single-marker estimate, this pedigree has the requisite power to find microsatellites linked to susceptibility loci for hip dysplasia and hip OA by breeding a reasonable number of backcross dogs.     

Ultrasonographic findings in horses with right dorsal colitis: five cases (2000-2001)

OBJECTIVE: To determine whether ultrasonography would be useful in the diagnosis of right dorsal colitis in horses. DESIGN: Retrospective study. ANIMALS: 5 horses with right dorsal colitis and 15 healthy adult horses. PROCEDURE: Mural thickness and appearance of the right dorsal colon were determined from ultrasonographic images obtained at right intercostal spaces 10, 11, 12, 13, and 14. RESULTS: The right dorsal colon could be imaged most consistently at the right 11th, 12th, and 13th intercostal spaces, below the margin of the lung and axial to the liver. Mural thickness measured from ultrasonographic images was significantly greater in horses with right dorsal colitis than in healthy horses. The right dorsal colon in affected horses had a prominent hypoechoic layer associated with submucosal edema and inflammatory infiltrates. Successful treatment of 1 horse with right dorsal colitis was associated with a decrease in mural thickness coincident with an increase in serum albumin and total protein concentrations and weight gain. A decrease in mural thickness was also observed in a second horse treated for right dorsal colitis that was not associated with healing of the right dorsal colon or an increase in serum albumin concentration but rather thinning of a segment of the right dorsal colon that eventually ruptured. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ultrasonographic measurement of mural thickness and evaluation of the appearance of the right dorsal colon may be useful in the diagnosis of right dorsal colitis in horses.