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221.
Research at La Venta, a major Olmec center on a low salt dome 12 kilometers from the Gulf Coast has revealed evidence of initial occupation (about 1750 to 1400 B.C.) along levees of the silted-in Río Barí, north of the site core in a transitional estuarine-riverine environment. Between 1400 and 1150 B.C. settlement expanded to nearby La Venta itself, which between 1150 and 800 B.C. developed into a major temple-town complex. Local development peaked at La Venta and along the river levees between 800 and 500 B.C. In this span La Venta headed a local three-tiered site hierarchy as social distinctions expanded to the peripheral Río Barí sites. New excavations show that growth in population size and density at La Venta preceded the development of sociopolitical complexity. These data contradict the traditional organizational reconstruction of Olmec society, the "vacant ceremonial center" model, and provide qualified support for a model that presents riverine resource concentration as a significant factor in the evolution of Olmec civilization. 相似文献
222.
Six shipments totaling 3452 mummies of the blackmargined aphid,Monellia caryella (Fitch), parasitized withAphelinus perpallidus Gahan, were obtained by air freight during the years 1982-1985 from Texas A&M Research Center, El Paso, Texas. About two-thirds of the mummies did not yield parasites. A colony ofA. perpallidus was established in the laboratory. Under laboratory conditions the percentage of emerged parasites was higher than that in the imported mummies, and the parasite had very limited impact on the aphid population. Field releases of the parasite were made but no establishment ofA. perpallidus was observed through the years. 相似文献
223.
Kevles DJ 《Science (New York, N.Y.)》1988,242(4883):1314-1315
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Adetunji A Pascoe PJ McDonell WN Horney FD 《The Canadian veterinary journal. La revue veterinaire canadienne》1984,25(9):342-346
A retrospective morbidity and mortality study was carried out on 125 case records of cattle involving xylazine/halothane anesthesia at the Ontario Veterinary College, Guelph between May 1979 and February 1983. 相似文献
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Anvik JO 《The Canadian veterinary journal. La revue veterinaire canadienne》1984,25(12):445-447
A seven month old domestic shorthaired male cat was presented with a known history of acetaminophen ingestion. Clinical findings included icterus, depression, hypothermia, tachypnea and pronounced edema of the head and neck. Treatment was aimed at providing substrate to assist in conjugation of the drug and reversing methemoglobinemia. Administration of oral acetylcysteine, ascorbic acid and IV fluids was insufficient in this case due to a delay in initiation of treatment. The salient postmortem findings were icterus, subcutaneous and pulmonary edema and evidence of hemolysis in the liver, spleen and urinary tract. 相似文献
230.
Norris AM Withrow SJ 《The Canadian veterinary journal. La revue veterinaire canadienne》1984,25(4):153-157
A review of the principles of cancer chemotherapy for pet animals is presented. The various pharmacological classes of antineoplastic drugs are described with specific references to those drugs that have been widely used in veterinary medicine. 相似文献