Epizootiologic aspects of viscerotropic velogenic Newcastle disease in six pet bird species

Pet birds of 6 species were exposed to a psittacine isolate to viscerotropic velogenic Newcastle disease (VVND) virus to evaluate the impact of VVND in those species. Species examined were the budgerigar, yellow-headed Amazon parrot, canary, halfmoon conure, lesser hill mynah, and blackheaded nun. Five of the 6 species were highly susceptible to infection with VVND virus. Canaries were relatively refractory to infection with the virus. Contact birds of the same species developed infections almost as rapidly as did the birds directly exposed to nebulized VVND virus. Mortality was most marked for the conures. Less than half of the parrots exposed to nebulized virus died of VVND. Of the directly exposed budgerigars, mynahs, and nuns, 16% to 22% died during an observation period of postexposure days 0 through 28.     

Nitrogen metabolism in sheep fed protein sources of various solubilities with low quality roughages

Four rumen-cannulated, mature crossbred wethers were used in a 4 x 4 latin square experiment designed to examine the effects on protein metabolism of protein sources with various solubilities fed with low quality roughages. Four diets were used: (1) grass hay plus oat straw (control), (2) control plus urea, (3) control plus soybean oil meal (SBOM) and (4) control plus sunflower oil mean (SFOM). The diets were isocaloric, isofibrous and isonitrogenous (1.60% except for the control, which contained 1.09% N). The protein solubility means determined by three solvents (Burroughs' mineral mixture, McDougal's artificial saliva and sodium chloride) were 23.7, 50.5, 18.2 and 24.2% for the respective diets. The average protein solubilities of SBOM and SFOM were 20.5 and 35.4%, respectively. Apparent crude protein digestibilites were higher (P less than .05) for diets with higher protein solubility. The Urea diet (highest protein solubility) resulted in higher urinary N excretion (P less than .05) and lower N retention than the SBOM and SFOM diets. N retention was similar for the animals fed the SBOM and SFOM diets. Ruminal NH3-N and plasma urea N levels were higher (P less than .05) in animals fed the urea diet. The protein source altered VFA concentrations but not C2 to C3 ratios of VFA. The SBOM and SFOM produced more branched chain fatty acids. These data illustrate that protein sources of higher solubility result in higher crude protein digestion and higher N loss in the urine. N balance was similar with SFOM and SBOM. SFOM and SBOM can be used interchangeably on an equal protein basis for sheep fed high roughage diets.     

Effect of oral administration of unfractionated heparin (UFH) on coagulation parameters in plasma and levels of urine and fecal heparin in dogs

The effects of heparin administration, by the oral route, were evaluated in dogs. In single and multiple dose studies (single 7.5 mg/kg, multiple 3 × 7.5 mg/kg per 48 h), plasma, urine, and fecal samples were collected at various times up to 120 h after oral administration of unfractionated heparin. Changes in plasma and urine anti-Xa activity, plasma and urine anti-IIa activity, plasma activated partial thromboplastin time (APTT) and antithrombin (ATIII), and chemical heparin in urine and feces were examined with time. There was support for heparin absorption, with significant differences in APTT, heparin in plasma as determined by anti-Xa activity (Heptest) in the single dose study and plasma anti-Xa activity, anti-IIa activity and ATIII; and chemical heparin in urine in the multiple dose study. No clinical evidence of bleeding was detected in any dog during the studies. Oral heparin therapy may be applicable for thromboembolic disease in animals. Further studies are warranted to determine the effects of oral heparin at the endothelial level in the dog.     

Climate Change During the Last Deglaciation in Antarctica

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated.     

A basal dromaeosaurid and size evolution preceding avian flight

Fossil evidence for changes in dinosaurs near the lineage leading to birds and the origin of flight has been sparse. A dinosaur from Mongolia represents the basal divergence within Dromaeosauridae. The taxon's small body size and phylogenetic position imply that extreme miniaturization was ancestral for Paraves (the clade including Avialae, Troodontidae, and Dromaeosauridae), phylogenetically earlier than where flight evolution is strongly inferred. In contrast to the sustained small body sizes among avialans throughout the Cretaceous Period, the two dinosaurian lineages most closely related to birds, dromaeosaurids and troodontids, underwent four independent events of gigantism, and in some lineages size increased by nearly three orders of magnitude. Thus, change in theropod body size leading to flight's origin was not unidirectional.     

奶花芸豆种植密度与施肥量优化组合模式的研究

采用正交回归旋转组合设计，研究了密度、氮（N）、磷（P2O5）、钾（K2O）施用量对奶花芸豆产量的影响，通过田间试验测定参数，利用计算机技术对试验数据进行处理，建立了产量函数模型，经计算机模拟寻优，筛选出了产量的最佳农艺措施组合方案。在试验条件下，当奶花芸豆栽培密度为150000株／hm^2，施氮量300kg／hm^2，施磷量200kg／hm^2，施钾量45kg／hm^2组合时，产量可达到3833．4kg／hm^2。