电导率对厌氧产酸、正渗透与微生物燃料电池耦合工艺运行性能的影响

将厌氧产酸(AA)、正渗透技术(FO)与微生物燃料电池(MFC)进行耦合,构建了用于污水处理的AAFO-MFC耦合工艺,实现污水的同步产电和回用.由于电导率是AAFO-MFC运行的关键因素,考察了电导率对系统运行性能的影响.结果表明,较高的电导率可以降低MFC的内阻,提高产电,但是会加重FO膜污染,导致FO膜通量快速衰减,缩短运行时间.电导率对出水水质并没有显著影响,FO膜出水的总有机碳(TOC)和总磷(TP)浓度分别低于4 mg·L~(-1)和0.5 mg·L~(-1),但是FO膜对于氨氮(NH+4-N)的截留效果较差.控制反应器内电导率为7~8 m S·cm-1时,系统整体性能表现最佳,可以获得连续且相对稳定的输出电压,而且FO膜通量下降较为缓慢,运行周期达到29 d.     

Prenatal diagnosis of a 46,XX/47,XX, +12 mosaic

A case of true mosaicism 46,XX/47,XX,+ 12 was diagnosed prenatally. The pregnancy was terminated in the 21st week of gestation and the aberrant cell line was rediscovered in cultured fetal tissue. However, a detailed examination of the fetus did not disclose any significant physical malformation.     

Prenatal diagnosis of a 45,X male with a SRY-bearing chromosome 21

Male phenotype associated with a 45,X karyotype is an infrequent finding. We present a case diagnosed prenatally on amniocentesis performed for maternal age. The male phenotype was associated with a translocation of a distal part of Yp including the pseudoautosomal SHOX gene and SRY gene on the short arm of a chromosome 21. By DNA analysis we could show that the X chromosome was of maternal origin and that the breakpoint was in interval 3 of the Y chromosome. Mechanisms and genetic counselling are discussed based on a review of published cases of 45,X and XX males. Copyright © 2002 John Wiley & Sons, Ltd.     

广西典型碳酸盐岩区农田土壤-作物系统重金属生物有效性及迁移富集特征

为揭示碳酸盐岩地质高背景区土壤重金属生态风险,选择广西典型的成土母岩为碳酸盐岩的土壤重金属高背景区,采集水稻籽实及对应根系土样品68套,在分析测试土壤、农作物籽实样品中砷(As)、镉(Cd)、铬(Cr)、铜(Cu)、汞(Hg)、镍(Ni)、铅(Pb)和锌(Zn)这8种重金属含量及土壤中重金属赋存形态的基础上,采用统计学、地累积指数、生物富集系数及相关性分析等方法开展土壤重金属生态风险研究.结果表明,研究区土壤中8种重金属平均含量明显高于全国和广西表层土壤的平均水平,其中Cd、As和Cr超过农用地土壤污染筛选值的比例分别达95. 6%、86. 8%和69. 1%,超过土壤污染管控值的比例分别为27. 9%、17. 6%和5. 9%.区内土壤中As、Cr、Cu、Ni、Pb和Zn主要以残渣态为主(残渣态占比 80%),显示出较低的生物活性; Cd的生物活性相对较高,生物有效态组分占20. 99%,但仍明显低于全国其它非碳酸盐岩地区的土壤; Hg的潜在生物有效态组分占44. 04%,然而土壤中Hg全量较低,因此其潜在生物有效态的绝对含量较低.与土壤相比,研究区水稻籽实中重金属超标率明显较低,仅部分样品中Cd、Cr、Pb超过国家食品限量标准,超标率分别为8. 8%、2. 9%和23. 5%.相关性分析显示,研究区土壤重金属全量与对应的水稻籽实中重金属含量不存在显著正相关关系.水稻籽实重金属生物富集能力普遍较低,8种重金属生物富集系数(BCF)的均值均小于0. 1,其中As、Cr、Hg、Ni和Pb的BCF均值小于0. 05.上述结果表明,对于碳酸盐岩等地质高背景区,相关部门在制定污染土壤管控政策时不能仅以土壤重金属全量作为衡量标准,应综合考虑金属赋存形态、生物活性及农作物超标率等因素.     

An Outbreak of Norovirus Infections Among Lunch Customers at a Restaurant,Tampere, Finland, 2015

On January 29, 2015, the city of Tampere environmental health officers were informed of a possible foodborne outbreak among customers who had eaten lunch in restaurant X. Employees of electric companies A and B had a sudden onset of gastrointestinal symptoms. We conducted a retrospective cohort study to identify the vehicle, source, and causative agent of the outbreak. A case was defined as an employee of companies A or B with diarrhea and/or vomiting who ate lunch at Restaurant X on January 26, 2015. All employees of the companies attending the implicated lunch were invited to participate in the cohort study. Environmental investigation was conducted. Twenty-one responders were included in statistical analysis, of which 11 met with the case definition. Of the 15 food items consumed by participants, four food items were associated with gastroenteritis. Of four kitchen staff, three tested positive for norovirus GIP7, the strain was found earlier in the community. No patient samples were obtained. Level of hygiene in the kitchen was inadequate. Infected kitchen staff probably transmitted norovirus by inadequate hygiene practices. No new cases associated with Restaurant X were reported after the hygiene practices were improved.     

Avoidance of nonhost plants by a bark beetle, Pityogenes bidentatus, in a forest of odors

The bark beetle, Pityogenes bidentatus (Coleoptera: Scolytidae), searches in mixed conifer and deciduous forests of northern Europe for suitable branches of its host, Scots pine (Pinus sylvestris). We tested whether odors from several diverse nonhost trees and plants common in the habitat (e.g., mountain ash, Sorbus aucuparia; oak, Quercus robur; alder buckthorn, Frangula alnus; blueberry, Vaccinium myrtillus; raspberry, Rubus idaeus; and grass, Deschampsia flexuosa) would reduce the attraction of the bark beetle to traps releasing its aggregation pheromone components in the field. Volatiles from the leaves or bark of each of these plants significantly reduced the attraction of the beetles to their pheromone. Odors collected from these nonhosts and analyzed by GC/MS contained monoterpenes, sesquiterpenes, and green-leaf alcohols, several of which (e.g., 1-octene-3-ol and -caryophyllene) reduced the attraction to pheromone in the field and elicited electroantennographic responses. In the laboratory, reproduction by the beetle was marginal in nonhost Norway spruce, Picea abies, and was absent in the other nonhost trees. Olfactory avoidance of unsuitable nonhosts may have evolved due to advantages in avoiding mistakes during host selection.     

Effects of a winter legume on phosphorus,potassium, calcium and magnesium cycling in a humid subtropical agroecosystem

Phosphorus, potassium, calcium and magnesium cycling were compared in sorghum agroecosystems with winter legume (Trifolium incarnatum L.) or inorganic fertilizer nitrogen inputs. The system with fertilizer N input had winter rye (Secale cereale L.) as a winter cover crop. Nutrient uptake by winter and summer crops, double acid extractable soil nutrients, soil pH and soil ammonium/nitrate ratio were measured. The legume took up more of all nutrients than the rye and also provided higher amounts of available nutrients in soil for the subsequent summer crop. Soil pH was also increased in the clover-N treatment. Nutrient uptake by winter crops is important for reducing leaching losses and chemical fixation of nutrients in humid subtropical regions.     

Prenatal diagnosis of a mosaic 46,XY/47,X,i (Xq)Y

A case of mosaic 46,XY/47,X,i(Xq)Y is diagnosed at 18 gestational weeks in amniotic fluid cells and confirmed at birth in the lymphocytes of the child. The literature on Klinefelter's syndromes with structural chromosome X rearrangements is reviewed. This is the first case reported of a mosaic isochromosome Xq in a boy.     

The lumisphere,a new model of pre-biotic evolution

Lyophilization of the amber-colored, fluorescent oils obtained via thermolysis of amino acid mixtures (Lys, Ala, Gly) leads to a cellular-structured material—with an average cell diameter of 50 μm. The cellular aggregates show a resemblance to epithel tissues. Single cellular entities find their analogs in Fox microspheres as well as in the microfossilsIsuasphaera. Short-wave UV (254 nm) irradiation of the aqueous suspensions destroys the cells, whereas suspension in saline solutions (NaCl) offers protection against dissolution by UV light. The fluorescence spectrum of the microscopic preparations containing the highly fluorescent cellular material (“lumispheres”) was registered.     

探索构建政府、市场和媒体三方共治的环境监管模式

政府在环境监管中发挥着无可替代的重要作用,但受行政资源约束等因素影响,监管能力存在局限性,亟需探索建立新的环境监管模式,保障环保事业的长期健康发展。文章认为应探索建立起政府、市场与媒体三方共同监督、协同治理的长效机制,对环境问题进行全程有效监管。建议政府应始终作为环境监管的中流砥柱,不断完善治理能力和体系的作用;市场需充分发挥激励机制,成为环境监管的价值准绳;媒体应有效发挥舆论监督作用,成为环境监管的良知之网。     

一株嗜酸硫氧化细菌的分离鉴定及生长特性

从北京清河污泥中分离出一株硫氧化细菌,命名为QH-1,并对该菌株进行了分离鉴定.同时,初步研究了该菌株对几种重金属离子的耐受能力.结果发现,该菌株为革兰氏阴性,短杆状,需氧型,可从氧化还原态的硫元素中获得能量.QH-1菌株具有很好的产酸和耐酸能力,培养24h后pH即可下降到2.0,1周内可达到1.0以下,对数生长期为15d,进入稳定期时pH降为0.6.QH-1菌株的16S rRNA基因测序与分析表明,该菌株与Acidithiobacillus thiooxidans strain AAU具有99%以上的16S rRNA基因序列相似性.通过构建该菌株在相关种属中的系统发育树,并结合形态与生理生化特征分析,将QH-1菌株鉴定为氧化硫嗜酸硫杆菌(Acidithiobacillus thiooxidans).QH-1菌株对Zn2+和Cu2+有一定的耐受性,对Mo2+的耐受性较差.     

Strategies of a bark beetle, Pityogenes bidentatus, in an olfactory landscape

 Volatiles from leaves or bark of nonhost birch (Betula pendula) and Norway spruce (Picea abies) dramatically reduced the attraction of the bark beetle, Pityogenes bidentatus (Coleoptera: Scolytidae), to their aggregation pheromone components (cis-verbenol and grandisol) in the field. In addition, odors from both the needles and bark of the host Scots pine (Pinus sylvestris) similarly inhibited attraction. Monoterpenes of pine and spruce (α-pinene, β-pinene, terpinolene, and 3-carene) as well as ethanol, chalcogran and some nonhost green leaf alcohols [(Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, and 1-hexanol], also reduced catches. Collections of volatiles from the field-tested plant tissues indicated they released monoterpenes in amounts similar to the synthetics that inhibited responses. The various plant and insect sources of these inhibitory compounds indicate that P. bidentatus bark beetles have evolved several strategies to increase their fitness by avoiding nonhost and unsuitable host trees in a complex olfactory landscape. Received: 6 June 2000 / Accepted in revised form: 25 September 2000     

Biodiversity,profitability, and vegetation structure in a Mexican coffee agroecosystem

We studied the relationships of bird and small mammal species richness, composition, and abundance to vegetation structure and economic profitability across a coffee intensification gradient in central Veracruz, Mexico. We conducted 2 years of point count censuses for summer resident birds, 2 years of Sherman live trapping for small mammals, and gathered vegetation structure data at 147 sampling points distributed over 16 sites spanning a cultivation intensification gradient. We calculated net annual revenue per hectare as an index of profitability from economic and management data collected during interviews with plantation owners/managers. Both the species richness and abundance of forest-affiliated birds were significantly greater in floristically and structurally diverse ‘bajo monte’ coffee and forest compared with commercial polyculture coffee, which was, in turn, significantly richer than statistically indistinguishable specialized shade and sun coffee. Mammal capture rates were extremely low at all but two sites. Forest bird species richness and abundance were explained by multiple linear regression models that included statistically significant effects of shade cover, percent of trees with epiphytes, and canopy height. We found no clear relationship between profitability and biodiversity, with biodiverse bajo monte coffee plantations ranking among the most profitable under all price scenarios. The high profitability of biodiverse bajo monte coffee systems was not dependent on the inclusion of long-term environmental costs or premium pricing systems. Our results demonstrate that high-biodiversity coffee cultivation can be compatible with high profitability, and has significant potential for conserving biodiversity in coffee-growing regions, but only as a substitute for low-biodiversity coffee cultivation, not forest.     

Evidence of a second gamete fusion after the first cleavage of the zygote in a 47,XX, + 18/70,XXX, + 18 mosaic. A remarkable diploid-triploid discrepancy after CVS

A 70,XXX, +18 karyotype was found by chorionic villus sampling, while the fetal fibroblast culture of the affected fetus revealed a 47,XX,+ 18 karyotype. From several possible mechanisms, we assume that a second gamete fusion occurred after the first cell division of the zygote. According to this interpretation, the mosaicism arose in very early pregnancy (at the two-cell stage). This discrepancy can therefore be explained by selection pressure, due to the differentiation processes in the embryonic tissues.     

Development of a generalist predator,Podisus maculiventris,on glucosinolate sequestering and nonsequestering prey

Insect herbivores exhibit various strategies to counter the toxic effects of plant chemical defenses. These strategies include the detoxification, excretion, and sequestration of plant secondary metabolites. The latter strategy is often considered to provide an additional benefit in that it provides herbivores with protection against natural enemies such as predators. Profiles of sequestered chemicals are influenced by the food plants from which these chemicals are derived. We compared the effects of sequestration and nonsequestration of plant secondary metabolites in two specialist herbivores on the development of a generalist predator, Podisus maculiventris. Profiles of glucosinolates, secondary metabolites characteristic for the Brassicaceae, are known to differ considerably both inter- and intraspecifically. Throughout their immature (=nymphal) development, the predator was fed on larval stages of either sequestering (turnip sawfly, Athalia rosae) or nonsequestering (small cabbage white butterfly, Pieris rapae) prey that in turn had been feeding on plants originating from three wild cabbage (Brassica oleracea) populations that have previously been shown to differ in their glucosinolate profiles. We compared survival, development time, and adult body mass as parameters for bug performance. Our results show that sequestration of glucosinolates by A. rosae only marginally affected the development of P. maculiventris. The effects of plant population on predator performance were variable. We suggest that sequestration of glucosinolates by A. rosae functions not only as a defensive mechanism against some predators, but may also be an alternative way of harmlessly dealing with plant allelochemicals.