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鸡败血支原体(Mycoplasma gallisepticum,MG)和滑液支原体(Mycoplasma synoviae,MS)在世界许多地区的重型鸡种中已被消灭;然而,在商品蛋鸡中,支原体感染仍为一大问题.最普遍的是 MS 感染,许多鸡群在感染后不表现明显  相似文献   
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In 15 horses with acute abdominal disease, a diagnosis of incarceration of small intestine through the epiploic foramen was made, either at the time of exploratory celiotomy or at necropsy.  相似文献   
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Colonic perforation after corticosteroid and surgical treatment of intervertebral disk disease in a dog Perforation of the distal segment of the descending colon, after corticosteroid and neurosurgical treatment for an intervertebral disk herniation, resulted in the death of a 3-year-old, male, Lhasa Apso. Initially, the dog was paraparetic in the hindlimbs, but became paraplegic after 4 days of conservative treatment. Corticosteroids were administered before referral and during decompressive hemilaminectomy. Six days after surgery, the dog had improved neurologically, but was depressed, anorectic, and vomiting. Abdominocentesis revealed septic peritonitis. The dog died shortly after a perforation in the descending colon was surgically corrected.  相似文献   
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Congenital aortic stenosis usually affects the subvalvular region, and occurs mainly in Newfoundland, Golden Retriever, German Shepherd, and Boxer dogs. The disorder is inherited as a dominant trait with variable penetrance in Newfoundland dogs.

The prevalence of subaortic stenosis-like heart murmurs in Golden Retriever dogs appears to be very much greater than previously suspected.

Most cases of aortic stenosis represent mild lesions, are detected as incidental findings, and result in no loss of longevity or quality of life. Moderate or severe stenosis may result in exertional weakness, syncope, or sudden death. Signs of congestive heart failure are rare unless mitral valve insufficiency is present.

Generally, electrocardiography and radiography are unrevealing in this disorder. Doppler echocardiography may be the best diagnostic tool to detect even mild cases of aortic stenosis.

At present, therapy is limited due to the technical expertise and expense required. The prognosis depends on the severity of the lesion.

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Much attention is focused today on predicting how plants will respond to anticipated changes in atmospheric composition and climate, and in particular to increases in CO(2) concentration. Here we review the long-term global fluctuations in atmospheric CO(2) concentration as a framework for understanding how current trends in atmospheric CO(2) concentration fit into a selective, evolutionary context. We then focus on an integrated approach for understanding how gas exchange metabolism responds to current environmental conditions, how it previously responded to glacial-interglacial conditions, and how it may respond to future changes in atmospheric CO(2) concentration.  相似文献   
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The open society     
Opel JR 《Science (New York, N.Y.)》1984,225(4660):378-380
The open society, unlike the closed society, requires constant citizen thought and action to ensure that it will continue to survive and prosper. Today in the United States we should give particular attention to three immediate problems. We should reinvigorate our national economic health and international competitiveness, particularly by reducing our unprecedented budget deficits and reforming our tax system. We must strengthen our scientific and engineering vitality, particularly in graduate engineering education and in secondary school instruction in science and mathematics. And we should work with our allies in the free industrialized world to keep our international open society as open as possible, encouraging a flow of people and information and ideas across national boundaries while instituting sensible and efficient safeguards against leakage of critical military technology to the Soviet Union.  相似文献   
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