The jump behavior of the humeroradial and tarsocrural joints of the horse

Osteoligamentous preparations of the elbow and hock joints of the horse show “jump” behavior when flexed and extended. This behavior is not seen in undissected anatomical specimens or in the live horse. The hypothesis is that energy is stored in the collateral ligaments during the middle range of joint displacement and quickly released nearing full flexion or extension. This energy storage mechanism has the attribute of negative work. In the undissected specimen and the live horse energy is stored in muscles and tendons as well as in the collateral ligaments, and the obvious jump phenomenon is not observed although the principle of negative work still pertains.     

Porcine malignant hyperthermia susceptibility: erythrocytic osmotic fragility

Erythrocyte osmotic fragility was determined in 27 Pietrain swine which were susceptible to malignant hyperthermia (MH), 29 Yorkshire swine which were resistant to MH (controls), and 50 crossbred swine (Pietrain x Yorkshire), half of which were MH susceptible. Halothane challenge tests and blood creatine kinase activity were used as criteria for determining MH susceptibility. Mean values for osmotic fragility of erythrocytes in concentrations of NaCl between 60 and 120 mM were significantly different for the 3 groups (P less than 0.001). Hemolysis (50%) of erythrocytes occurred at NaCl concentrations of 90 mM for Pietrains, 85 mM for crossbreds, and 78 mM for controls. Increased fragility values occurred in 96% of the Pietrains, 3% of the controls, and 42% of crossbred swine that were halothane test-positive, and 58% of halothane test-negative crossbreds (P less than 0.05). The mean time of onset of signs of MH in response to halothane challenge testing was twice as long in the crossbreds as in Pietrains (P less than 0.01). Reticulocyte counts were moderately high in blood samples from both the Pietrains (P less than 0.001) and the crossbreds (P less than 0.05). Of the swine which were tested for erythrocyte selenium-dependent glutathione peroxidase activity, values were within acceptable laboratory limits in 18 of 20 Pietrains, 14 of 14 halothane test-negative crossbreds, and 8 of 8 halothane test-positive crossbreds. In 2 of 20 Pietrains, a 35% deficiency of this enzyme was found. Heinz bodies were not detected in erythrocytes examined from 21 Pietrains, 20 crossbred swine (8 halothane test positives), and 12 controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prediction of total phenols,condensed tannins,and 3-deoxyanthocyanidins in sorghum grain using near-infrared (NIR) spectroscopy

The reported high phenolic levels in sorghum have led an interest from sorghum breeding programs in developing and identifying germplasms with high phenolic levels, which require screening a large number of samples to find those with the highest levels. Since wet chemistry screening methods are slow, expensive, and destructive, the use of NIR calibration curves could be an alternative. The objectives of this project were to determine the variation range in total phenols, condensed tannins, and 3-deoxyanthocyanidin levels in a diverse set of sorghum genotypes and to assess the predictive value of NIR curves to estimate these compounds in sorghum. A calibration curve to estimate each compound was developed and validated with an independent validation set. Calibration curve correlations for total phenols, condensed tannins, and 3-deoxyanthocyanidins were r = 0.98, 0.97, and 0.99, respectively. Correlations between NIR-predicted values and reference values in the validation set were significant for total phenols (r = 0.93), condensed tannins (r = 0.81) and 3-deoxyanthocyanidin (r = 0.82). These indicated that sufficient variation for these compounds existed within sorghum and that NIR calibration curves could be used to rapidly and non-destructively predict total phenols, condensed tannins, and 3-deoxyanthocyanidins concentrations in whole grain sorghum.     

Antifungal proteins in commercial hybrids and elite sorghums

The antifungal proteins (AFP) in the caryopsis of commercial and elite sorghums grown in several environments were related to grain mold resistance. Previous studies revealed that improved grain mold resistance was correlated with higher levels of AFP at combine harvest maturity [50 days after anthesis (DAA)] or with better retention of AFP after physiological maturity (30 DAA). Commercial hybrids and public parental lines and hybrids were grown in College Station, TX, during 2000, 2001, and 2002. Samples of caryopses were collected at 30 and 50 DAA, and caryopsis proteins were extracted, blotted, identified with immunoassays, and quantified for two AFP (chitinase and sormatin). Sorghums varied in amounts of AFP and their ability to retain AFP after physiological maturity. The environment in 2002 was conducive for fungal deterioration of grain, and a wide range of AFP and grain molding was observed at harvest maturity. High levels of AFP and low levels of grain molding were observed in non-mold-conducive environments in 2000 and 2001. Commercial and elite sorghums with higher levels and increased retention of AFP had less grain molding in the mold-conducive environment.     

Impulse and breakdown on straights and turns in racehorses

Consideration of the impulse (force multiplied by time) experienced by legs of racehorses indicates that the portion of the force directed sideways on the sloping straight parts of race courses and centripetally on underbanked turns is related to the incidence of breakdown, fracture, of the legs. Better racehorses have smoother impulse patterns.