Diet-related risk factors for gastric dilatation-volvulus in dogs of high-risk breeds

A nested case-control study was conducted among 1634 dogs with complete diet information in a 5-year prospective study to determine diet-related risk factors for gastric dilatation-volvulus (GDV). Cases included 106 dogs that developed GDV; controls included 212 dogs without GDV that were frequency matched to cases by year of GDV onset. Proportionate energy consumed from major food types and from carbohydrates was determined. Dogs were categorized as consuming either a low volume or high volume of food based on the median number of cups of food fed per kg of body weight per meal. Dogs fed a larger volume of food per meal were at a significantly (P<0.05) increased risk of GDV, regardless of the number of meals fed daily. For both large- and giant-breed dogs, the risk of GDV was highest for dogs fed a larger volume of food once daily.     

Role of the generative cell in androgenesis in henbane

When anthers of henbane containing uninucleate pollen grains were cultured, a large number of embryoids originated exclusively from the division of the generative cell. In a small proportion of pollen grains, both generative and vegetative cells contributed to embryoid formation. Embryogenesis by segmentation of the vegetative cell alone was rarely observed.     

Influence of operating parameters on the use of the microwave-assisted process (MAP) for the extraction of azadirachtin-related limonoids from neem (Azadirachta indica) under atmospheric pressure conditions

The use of the microwave-assisted process (MAP) for the extraction of azadirachtin-related limonoids (AZRL) from various parts of the neem tree was investigated under different operating conditions. The influence of microwave power, solvent, and irradiation time on the recovery of AZRL was studied. The efficiency of the microwave-assisted extraction (MAE) of the seed kernel, the seed shell, the leaf, and the leaf stem was compared to that of conventional extraction methods. The content of AZRL in the extracts was estimated with a vanillin-based colorimetric assay and a multivariate calibration technique. The results showed that the MAE technique can enhance the extraction of AZRL from different parts of neem possessing microstructures. Investigation of the influence of the solvent also indicted that the solvent used not only influences the efficiency but also affects the selectivity of the MAE.     

Physico-mechanical properties and yield of silage corn as affected by soil compaction and tillage methods

Experimental investigations were conducted over three years to test the hypothesis that soil compaction affects the physical and mechanical properties of corn ears and corn cobs. Field experiments were made on sub-drained clay and sandy loam soils at Macdonald College Farm in Quebec Province of Canada. The mechanical properties of corn ears and corn cobs were determined from quasi-static force-deformation analysis performed with a universal Instron testing machine.

The results showed that soil compaction treatments did not significantly influence corn cob elastic modulus and strength in simple bending nor in radial compression. Cob moisture content did not significantly change as a result of the application of various traffic treatments. However, corn cob diameter and pith diameter were both significantly affected by soil compaction.

Corn ear moisture content and bending strength were not significantly affected by soil compaction. However, corn ear yield in all three years was found to be dependent on the amount of soil compaction applied.

Also studied were the effects of various tillage methods in ameliorating the deleterious effects of soil compaction on crop yield and crop quality. It is concluded that a judicious choice of tillage machinery system can minimize the reductions in ear yield due to soil compaction.     

Distribution of exogenous delta-tocopherol between the membrane lipids and triacylglycerols of a cod muscle-triacylglycerol model system

Membranes of muscle foods are more susceptible to oxidation than triacylglycerols. Hence, directing a lipid-soluble antioxidant into the membranes may reduce the oxidative deterioration of muscle tissue. The objective of this research was to use a model system of cod muscle and triacylglycerol to study the distribution of exogenous delta-tocopherol between the membranes and triacylglycerol fractions of muscle. When ethanol was the carrier solvent, more tocopherol was incorporated into the membranes than when oil was the carrier. Addition of tocopherol to the muscle before the triacylglycerol was added allowed more antioxidant to be incorporated into the membranes than for the case when the oil was added before the antioxidant. When the triacylglycerol was solid, the amount of tocopherol incorporated into the membranes was higher than if the triacylglycerol was liquid and the amount of tocopherol incorporated into the membranes was less dependent on the order of tocopherol and triacylglycerol addition. There was a competition between the membrane lipids and triacylglycerol for uptake of the delta-tocopherol. In some circumstances, some of the tocopherol did not enter either the membrane lipid or triacylglycerol phase.     

Eff icacy of angler catch data as a population and conservation monitoring tool for the f lagship Mahseer f ishes (Tor spp.) of Southern India

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Antioxidative activity of protein hydrolysates prepared from alkaline-aided channel catfish protein isolates

Antioxidative activity of hydrolyzed protein prepared from alkali-solubilized catfish protein isolates was studied. The isolates were hydrolyzed to 5, 15, and 30% degree of hydrolysis using the protease enzyme, Protamex. Hydrolyzed protein was separated into hydrolysates and soluble supernatants, and both of these fractions were studied for their metal chelating ability, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and their ability to inhibit the formation of thiobarbituric acid reactive substances (TBARS) in washed tilapia muscle containing tilapia hemolysate. Both hydrolysates and supernatants were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results showed that DPPH radical scavenging ability and reducing power of catfish protein hydrolysates decreased, whereas the ORAC value, metal chelating ability, and ability to inhibit TBARS increased, with an increase in the degree of hydrolysis. Hydrolysate samples showed higher DPPH radical scavenging ability and Fe(3+) reducing ability, and supernatant samples had higher metal chelating ability. In general, low molecular weight (MW) peptides had high ORAC values and high metal chelating ability, and high MW peptides had a higher reducing power (FRAP) and were more effective in scavenging DPPH radicals. In a washed muscle model system, the ability of catfish protein hydrolysates and their corresponding supernatants to inhibit the formation of TBARS increased with an increase in the degree of hydrolysis.     

Antioxidative efficacy of alkali-treated tilapia protein hydrolysates: a comparative study of five enzymes

The antioxidant activities of alkali-treated tilapia protein hydrolysates were determined by their ability to inhibit the formation of lipid hydroperoxides (PV) and thiobarbituric acid reactive substances (TBARS) in a washed muscle model system and by their ability to inhibit DPPH free radicals and chelate ferrous ion in an aqueous solution. Protein isolates were prepared from tilapia white muscle using alkali solubilization at pH 11.0 and reprecipitation at pH 5.5. Protein hydrolysates were prepared by hydrolyzing the isolates using five different enzymes, Cryotin F, Protease A Amano, Protease N Amano, Flavourzyme, and Neutrase, to 7.5, 15, and 25% degrees of hydrolysis (DH). All of the protein hydrolysates significantly (p<0.05) inhibited the development of TBARS and PV. The antioxidant activity of the hydrolysates increased with the DH. Also, the antioxidant activity of the hydrolysates varied significantly (p<0.05) among the different enzymes. The ability of different enzyme-catalyzed protein hydrolysates to scavenge DPPH radicals was not reflected in their ability to inhibit oxidation in a washed tilapia model system. In a washed muscle model system, the hydrolysates prepared using Cryotin F were most effective and the hydrolysates prepared using Flavourzyme and Neutrase were least effective in inhibiting the development of TBARS and PV, whereas in an aqueous solution, hydrolysates prepared using Flavourzyme were most effective in scavenging DPPH radicals and chelating ferrous ions. Enzymatic hydrolysis decreased the size of tilapia protein hydrolysates and, in general, tilapia protein hydrolysates with low molecular weights were better antioxidants than those with high molecular weights.     

Herbicidal potential of ophiobolins produced by Drechslera gigantea

Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds.