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811.
Preimplantation genetic diagnosis (PGD) is an alternative to prenatal diagnosis for couples at risk of transmitting genetic disorders to their offspring. We present a fluorescence in situ hybridization (FISH) analysis of embryos obtained after seven PGD cycles in six couples with Robertsonian translocations and male factor infertility: 4 der(13;14), 1 der(14;21) and 1 der(15;21). Of 74 metaphase II (MII) injected oocytes, 61 (82.4%) fertilized normally and cleaved. Of these, 37/61 (60.7%) embryos were of high morphological quality with ≥6 blastomeres. After biopsy of 44 embryos at day 3 of development, seven degenerated, seven arrested in development and 30/44 (68.2%) evolved, of which 25/30 (83.3%) reached the morula/blastocyst stage. Analysis of biopsied blastomeres showed 23/44 (52.3%) of normal/balanced embryos, of which 15 (11 at the morula/blastocyst stage) were transferred in six cycles. One term pregnancy was achieved, which ended by cesarean section at 37 weeks of gestation, giving birth to two healthy newborn. Analysis of 49 embryos (excluding 12 inconclusive cases) showed a predominance of alternate segregation (38/49, 77.6%) over adjacent segregation (7/49, 14.3%), with one (2%) being a polyploid mosaic and three (6.1%) chaotic. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
812.
K. B. Gongalsky Zh. V. Filimonova A. D. Pokarzhevskii R. O. Butovsky 《Russian Journal of Ecology》2007,38(1):52-57
The influence of the Kosogorsky Metallurgical Plant (KMP; Tula region, Russia) on the abundance and biodiversity of carabid beetles and soil macrofauna and on the trophic activity of soil biota was studied. Metal concentrations in the impact plot were many times higher than those in the control plot located on the same transect. As the transect approached KMP, both the abundance of soil invertebrates (geobionts) and trophic activity of the soil biota remained unchanged, whereas the abundance and diversity of carabids (herpetobionts) decreased drastically. It is suggested that the impact of the KMP on herpetobionts is accounted for by modification of the structure of ecosystems and that herpetobiontic and geobiontic groups of the macrofauna respond differently to this impact because of differences in the ecological mechanisms of population response. 相似文献
813.
General trends in simplification of the structure and composition of forest communities in the zone of impact from the metallurgical industry are revealed. The load of toxicants is estimated from the concentrations of heavy metals in the snow and soil. The method is proposed for assessing biological damage on the basis of the main characteristics of phytocenosis, such as its species diversity and the cenotic significance of its structural components. The resultant integrated index of phytocenosis preservation (IIP
p) characterizes the degree of biological damage, and its value depends on the load of toxicants and resistance of plant communities characteristic of different natural zones. 相似文献
814.
Paleoethnobotanical materials and buried soils from the site of the ancient settlement of Idnakar and neighboring archaeological monuments were analyzed to reconstruct the agroecosystems of the 9th through the 13th centuries AD near the present-day city of Glazov. The results provided data on the main features of the agroecosystem structure and composition, climate, and agriculture in the Middle Ages. 相似文献
815.
Herwig Peeters 《Environment, Development and Sustainability》2003,5(1-2):197-230
The incapacity to finance sustainable development through philanthropic official assistance turned the Johannesburg Summit to business world and the financial industry. Pioneering financial institutions – including development banks and private banks – have developed a wide range of innovations that can support sustainable development. This article highlights a few innovative products and markets and focuses on the progress made by financial players on the level of standards, metrics and guidelines to improve sustainability management systems, reporting and accounting practices and the multi-stakeholder dynamic. The role of the socially responsible investing (SRI) community has been underexposed by the Summit. Through its voice and market success, SRI has moved from a green market niche to the mainstream, however not becoming mainstream. The invaluable levering effect of SRI has just been discovered by authorities and market regulators and is becoming instrumental. In order to show the business case of Corporate Social Responsibility and to prove the financial viability of the People, Planet, Prosperity investing approach, the SRI community should critically reflect on its own quality assurance systems, sound disclosure and verification practices. 相似文献
816.
滇池水华蓝藻干粉制剂的生物脱毒实验 总被引:7,自引:0,他引:7
滇池属长江流域的一个内陆湖泊,近年来水体富营养化日益严重,每年夏季都出现大面积的水华。由品种单一,主要为蓝藻门,其中微囊藻是优势种,产生的微囊藻毒素具有很强的毒性。本实验以富营养化湖湖滇池中的水华蓝藻作为主要原料,将其制成干粉后,利用双协菌株在28-32℃条件下对其进行固态发酵,培养基质初始水份为65%。发酵培养2d后,培养基质中微囊藻毒素含量明显降低,6d后,基质中微囊藻毒素含量未检出(最低浓度检测限1μg/mg)。同时对实验所获得时间序列进行动力学研究,结果表明利用双协菌降解微囊藻毒毒的反应为准一级动力学反应。 相似文献
817.
At Loch Fleet, and in other liming studies in similar environments, catchment liming is successful if an adequate amount of lime is added to hydrological source areas. Geochemical modelling demonstrates that the relatively late acidification of L. Fleet is consistent with the ameliorating effect of an alkaline groundwater input: the presence of this input implies that had the Loch not been limed in 1985 it would have recovered to conditions suitable for fish in about 20 years, given current commitments to sulphur emission reductions. Lakes without similar alkaline groundwater are not likely to recover as quickly. the different consequences of liming and emission reduction as methods of restoring acid waters are reviewed and contrasted. Restoration of waters by liming may result in some undesirable effects on the terrestrial catchment: these are discussed but it is concluded that catchment liming, used with discrimination, can be an acceptable management tool. 相似文献
818.
向赤忠 《长江流域资源与环境》1993,2(3):253-260
根据径流场观测材料、调查资料及历史事实,论述了乌江流域(四川部分)的水土流失现状、特点、危害及导致水土流失的自然因素和人为因素。针对该流域水土流失特点和原因提出了防治对策。 相似文献
819.
两种消化方法对无齿相手蟹重金属含量测定结果的影响 总被引:2,自引:0,他引:2
生物样品分别经湿灰法和干灰法消化处理后,测定其Zn,Cu和Pb的含量。结果表明,不同消化方法对样品中Cu含量的测定没有显著的影响,而对Zn和Pb含量的测定都有显著的影响,湿灰法处理后样品中Zn和Pb含量的测定值均普遍高于干灰法处理后相应的测定值。根据本研究结果可知。测定Cu含量的生物样品可用常规灰化温度进行处理,而测定Zn和Pb含量的生物样品宜用低温灰化技术进行处理。图6表1参12 相似文献
820.
重金属元素在樟树人工林中的累积与迁移 总被引:4,自引:0,他引:4
结合樟树人工林生态系统生物产量研究,采用Hp3510原子吸收分光光度法测定樟树人工林生态系统不同组分中Cu、Zn、Mn、Pd、Ni、Cd的含量,探讨了重金属元素Cu、Zn、Mn、Pb、Ni、Cd在湖南株洲市樟树人工林中的累积与迁移.结果表明,樟树人工林地土壤层(0~100 cm)中,6种重金属元素的平均含量以Pb为最高,为67.929 mg/kg,Cd最低,仅为0.699 mg/kg,排序为Pb>Zn>Mn>Ni>Cu>Cd,总储量为2 737 174 kg/hm2.在樟树不同器官中,Cu、Zn、Mn、Pd、Ni、Cd的含量范围分别为6.849~13.178 mg/kg,3.776~37.443 mg/kg,32.214~659.130 mg/kg,1.626~15.544 mg/kg,0.218~3.719 mg/kg,1.033~9.506 mg/kg.樟树对土壤中6种重金属元素富集能力排序为Cd>Mn>Zn>Cu>Pb>Ni.在樟树林中,6种重金属元素的总积累量为11.124 kg/hm2,且排序为Mn(8.097 kg/hm2)>Zn(1.429 kg/hm2)>Cu(0.763 kg/hm2)>Pb(0.491 kg/hm2)> Cd(0.272 kg/hm2)>Ni(0.072 kg/hm2),重金属元素积累量空间分布为叶(3.447 kg/hm2)>枝(2.863 kg/hm2)>皮(1.685 kg/hm2)>干(1.635 kg/hm2)>根(1.307 kg/hm2).樟树林与环境之间,Mn的交换能力最强,其次是Cd、Zn、Cu,再次为Ni、Pb. 相似文献