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931.
932.
In some lines and F1 hybrids of winter hexaploid triticale ( xTriticosecale Witt.), significant positive associations were found amongst leaf anatomy, plant morphology, chlorophyll content, photochemical activity of chloroplasts, and photosynthetic or grain productivity. The data may be useful in practical triticale breeding.  相似文献   
933.
对以苇状羊茅占优势的人工草地分别于生长第一二年进行利用比较试验,结果表明:始用期和始牧草层高度不同,对草地生产力、牧草越夏率及杂草侵染程度具有明显影响.  相似文献   
934.
Objective To describe the clinical and histological appearance of persistent fetal intraocular vasculature in a colony of ferrets.
Design Prospective study.
Animals studied Eighty-six European ferrets ( Mustela putorius ).
Procedure Both eyes of 76 genetically related progeny and 10 breeding, adult, colony-raised ferrets were studied using a slit lamp biomicroscope and an indirect ophthalmoscope. Ferret progeny were examined after eyelid opening at 5–6 weeks of age, and at 12 months of age. After euthanasia, globes were enucleated and examined histologically.
Results Persistent fetal intraocular vasculature was evident in 21 progeny ferrets at 5–6 weeks of age and in three mature progenitor ferrets. Clinical appearance of diminutive vasculature was characterized by focal remnants of the posterior tunica vasculosa lentis, muscae volitantes, and an occluded hyaloid artery extending from the optic papilla and terminating in the anterior vitreous body. Extensive persistent vasculature was characterized by a perfused hyaloid artery, vasa hyaloidea propria and posterior tunica vasculosa lentis, posterior cortical and capsular cataract, and proliferation of fibrovascular tissue along the posterior lens capsule. Fetal vasculature persisted in 7 of 21 progeny ferrets at one year of age and in three progenitor ferrets. Results of histologic examination showed persistence of the hyaloid vasculature, proliferation of retrolental fibrovascular tissue with osseous metaplasia, posterior capsular and cortical cataract, and occasional retinal detachment.
Conclusions Persistent fetal intraocular vasculature in ferrets appears similar clinically and histologically to persistent fetal intraocular vasculature reported in humans and dogs. The ferret may be a suitable animal model for vasculogenic mechanisms of persistent fetal intraocular vasculature and for evaluating vasoinhibitory growth factors and angiostatic test compounds.  相似文献   
935.
Persistent hyperplastic primary vitreous (PHPV) syndrome associated with either severe ocular complications or multiple ocular lesions was diagnosed in three young dogs, a Samoyed, a Spanish Pachon, and a mixed breed dog. Due to opacification of the anterior ocular structures, B-mode and color-flow Doppler ultrasonography were performed to aid diagnosis. The Samoyed presented with unilateral hyphema; the Spanish Pachon presented with unilateral secondary glaucoma associated with uveitis and hyphema OD and leucocoria OU; and the mixed breed presented with bilateral leucocoria. B-mode ultrasonography of the Samoyed revealed a subcapsular cataract and a hyperechoic tubular structure attached from the optic disk to the posterior lens capsule. In the Spanish Pachon B-mode ultrasonography of the right eye indicated microphakia, cataract formation, and a retrolental mass with a thin hyperechoic strand stretching from the optic disk to the posterior lens; and for the right eye cataract formation, PHPV, retinal detachment, and vitreous hemorrhage. In the mixed breed dog, B-mode ultrasonography of both eyes indicated microphthalmia, retrolental mass, and hyperechoic lenses. By color-flow Doppler imaging, blood flow was present in the retrolental mass of the right eye suggesting a persistent hyaloid artery.  相似文献   
936.
A study concerning performance traits of the Ethiopian camel indicated that, in the camel herds examined, there was one active bull camel for 25 females. The bull camel was 5 years old at puberty; it reached rutting vigour at the age of 9 years, the number of mountings per day was 8 during the breeding season, and the reproduction span was 10 years. The female camel reached puberty at 4 years of age; the age at first calving was 5 years, and the lactation period was one year; the calving interval was 2 years, the calving rate was 50%, and the reproduction span was 10–15 years. The survival rate of the newborn calves was 50%. The average milk yield was 2.5 L per day; the price of camel's milk was higher than that of cow's milk at US$0.5. Adult camels weighed around 500 kg; the dressing-out percentage was 52%. Mutton was preferred to camel meat, which came second in popularity, costing US$2/kg. Owing to their poor reproductive performance, camels are not efficient for producing meat. The camels worked for 16 h per day, covering 60 km. Animal health problems encountered were trypanosomosis, camel pox, camel pustular dermatitis, camel cephalopsis, dermatomycosis, mange mite, tick infestation and balantidiosis, most of which mainly affected the young animals.  相似文献   
937.
总适应能力是指绵、山羊品种在被引入地区的自然生态环境和饲养管理条件相互作用下,所表现出的繁殖力、生产力和经济效果的总和,是衡量绵、山羊品种在被引入地区是否适应,及其适应程度的客观数量化指标。本文对总适应能力的组份,按其相对重要性进行剖分,并对其评定项目、计算得分方法和相应的总适应能力等级进行了阐述。  相似文献   
938.
The objective of this study was to describe the clinical, histologic and immunohistochemical features, the surgical treatment, and outcome of a cataract secondary to persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous (PHTVL/PHPV) in a dog. A 4-month-old male Bloodhound dog presented for evaluation of a cataract. A complete ophthalmic examination and ocular ultrasonography were performed. A resorbing cataract with intralenticular hemorrhage, lens induced uveitis, and PHTVL/PHPV were diagnosed. Extracapsular cataract extraction using phacoemulsification was performed. A primary posterior capsulectomy was performed to remove a retrolental plaque with the posterior capsule; the excised plaque was submitted for histopathology and immunohistochemical staining. A 41-Diopter intraocular lens (IOL) was implanted. Functional vision was maintained postoperatively during the 21-month follow-up period. Histologically, the posterior capsule was coiled and exhibited duplication. The retrolental plaque was comprised of dense fibrous connective tissue, blood vessels, free red blood cells, hemosiderin-laden macrophages, a pocket of neural tissue and numerous perivascular mast cells. With immunohistochemical staining, the neural elements were determined to be glial cells compatible with astrocytes. Cataract secondary to PHTVL/PHPV can be successfully treated using phacoemulsification and planned posterior capsulectomy. Posterior lens capsule duplication, mast cells and astrocytic glial cells may be normal components of the fibrovascular retrolental plaque associated with PHTVL/PHPV.  相似文献   
939.
广西合浦窿缘桉海防林生物量和生产力的研究   总被引:9,自引:0,他引:9  
用空间代替时间与定点连续观测相结合的方法,对0.7 ̄7.7a生窿级桉海防林的生物量和生产力进行了研究。结果表明,窿缘桉林分的生物量是随着林分年龄的增长面增加,即由造林初期的2.77t/hm^2增加到主伐期的70.932t/hm^2。不同年龄林分生物量的器官分配存在一定的变化,干材占总生物量的42.53% ̄56.34%,干皮12.16% ̄17.25%,光枝3.85% ̄5.30%,叶枝0.76% ̄4.  相似文献   
940.
以意大利蜜蜂为材料 ,把定期割雄蜂蛹的蜂群作为试验组 ,不割雄蜂蛹的蜂群作为对照组 ,定期测定两组蜂群的生产力、繁殖力及分蜂性 .结果表明 :两组蜂群的产浆量、繁殖力及分蜂性都差异不显著 ,但对照组的产蜜量比试验组高 8.4 %~ 10 .0 % .由以上结果 ,作者提出 :在养蜂生产中 ,养蜂者不必割雄蜂蛹  相似文献   
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