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41.
种植方式和灌溉定额对碱化盐土及紫穗槐生长的影响   总被引:1,自引:3,他引:1  
针对甘肃白银碱化盐土表层土壤盐分高、植物生长困难的生产问题,在统一施用脱硫石膏18t/hm^2的基础上,通过2 a田间试验,在起垄沟植和未起垄种植2种种植方式下设置3个灌溉定额:8 250、9 750和11 250 m^3/hm^2,研究不同种植方式及灌溉定额对土壤pH值、碱化度、含盐量及紫穗槐生长的影响。试验结果表明:1)各处理均显著降低了土壤pH值、碱化度和含盐量;起垄沟植方式下垄沟内可汇集灌溉水和降水,提高土壤含水率;在0~40 cm土层起垄处理的土壤盐分比未起垄处理低15.7%,起垄沟植处理可以形成"高水低盐"的水盐环境,从而使紫穗槐的成活率、株高、冠幅均高于未起垄处理;2)2种种植方式下,随灌水量增加脱盐效果越显著,紫穗槐的成活率、株高、冠幅指标随灌水量增加而增加;灌溉定额为9 750和11 250 m^3/hm^2时,紫穗槐生长指标无显著差异。考虑到研究区地处干旱区,水资源有限,灌水量过多不仅浪费水资源还会增加发生次生盐渍化的风险,因此,施用脱硫石膏并起垄沟植适宜于甘肃白银碱化盐土紫穗槐种植,且适宜灌溉定额为9 750 m^3/hm^2。  相似文献   
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Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group.  相似文献   
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Cryopreservation is a modern technique which assists in the preservation of genetic material from oocytes and embryos for a long time. However, elevated vulnerability to cryopreservation due to the large accumulation of intracellular lipids within oocytes or embryos avoids success of this method. These lipids remain the main crucial factor limiting survival rates of oocytes and embryos after thawing. Lipid ingathering in the oocyte cytoplasm augments lipid peroxidation (LPO) and oxidative stress increases the apoptosis process, declines the viability after thawing, declines cytoskeleton actin filament injuries, lowers the blastocyst rates and reduces cryotolerance in the early stages of embryo development. There have been several attempts to reduce the ingathering of intracellular lipids in oocytes or embryos during the cryopreservation process, in that way enhancing the competence of cryopreserved oocytes or embryos and increasing their viability. One of the most applied agents for chemical delipidation is forskolin. Forskolin exhibited a possible part in improving the oocytes cryopreservation through stimulating cyclic adenosine monophosphate (cAMP) production. The main purpose of cAMP modulation is to provide energy to sustain the mammalian oocytes´ meiotic arrest. The purpose of the existing article is to assess and offer more evidence concerning the forskolin utilization as a modulator of cAMP during the cryopreservation of oocytes and its influence on meiosis completion and the reorganization of cytoplasm, which are prerequisites for the development of oocytes in addition to the contribution to fertilization and subsequently, the development of embryos.  相似文献   
44.
Owners of small backyard poultry and swine operations may be at higher risk of zoonotic diseases due to husbandry inexperience and/or a lack of knowledge. Backyard poultry and swine owners in southcentral Pennsylvania were surveyed regarding their knowledge and attitudes towards zoonotic disease prevention. One hundred and six backyard poultry and/or swine owners completed the survey (74 poultry, 15 swine, 17 both), which included questions on demographics, flock/herd characteristics, recognition of selected zoonotic diseases and clinical signs in animals, and biosecurity practices for visitors and owners. Most responded that they were aware of avian (92.2%) and swine (84.4%) influenza, and were less aware of other zoonotic diseases such as salmonellosis and brucellosis. The majority of backyard poultry and swine owners combined (62.9%) reported allowing visitors freely around their animals and did not require any special precautions. Backyard poultry and swine owners most commonly reported rarely (32.7%) or never (28.9%) wearing work gloves and never (57.1%) wearing nose/mouth coverings, such as a respirator mask, while handling animals or manure. The study findings indicated that veterinarians (61.5%) and the Internet (50.0%) are the main sources where small‐scale farm producers seek animal disease information. Approximately one‐third (34.9%) of the respondents reported receiving seasonal influenza vaccine. The findings of this study will be utilized to provide targeted veterinary and public health education for the prevention of zoonotic diseases in backyard farm animal settings in Pennsylvania.  相似文献   
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In the late fall of 2004 more severe lesions of porcine circovirus-2 associated disease (PCVAD) than usual occurred during an outbreak of porcine circovirus-2 (PCV-2) infection in Ontario nursery and grower/finisher pigs. The lesions were of unprecedented severity and included diffuse bronchointerstitial pneumonia, granulomatous enteritis, vasculitis, interstitial nephritis, and new lesions of splenic infarction. Some affected herds had up to 50% mortality. The outbreak correlated with the sudden emergence of a variant PCV-2, with PCR restriction fragment length polymorphism (RFLP) type 321. Phylogenetic comparison of ORF2 sequences and full genome sequences showed the new variant to be different from the previously dominant RFLP type 422 viruses, and similar to viruses that had occurred in France and other European and Asian countries. A subsequent retrospective study showed a statistically significant increase in the frequency of histological lesions in lymph node, spleen, lung, small intestine, colon and kidney, for pigs spontaneously infected with RFLP type 321, compared with the older RFLP type 422 strain. Viral burden, based on IHC staining in lymph node, also showed a statistically significant increase in pigs infected with the newer variant RFLP type 321, compared with the older RFLP type 422 strain. This enhanced virulence in pigs infected with PCV-2 RFLP type 321 strain may be related to the genetic differences in this new strain of PCV-2. This virus is now the dominant strain of PCV-2 virus found in Ontario and Quebec swine.  相似文献   
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