基于卫星图像的村庄真实形态评价:一种识别欧洲完整文化景观的方法

土地由中心到边缘呈现不同分布利用方式的村庄,构成了欧洲文化景观的基本单元.然而在许多的乡村景观中,那些拥有细致结构的耕地和有树木的草场的真正前工业时代的村庄正在不断失去其原有的结构,这种遗失威胁着文化的继承和生物多样性.因此,监测景观中这样的村庄真实形态的变化范围和速度是非常重要的.随着废弃时间的增加,村庄的真实形态不断丢失,我们所要研究的是怎样的丢失程度才能够通过卫星图像定量分析和目视解译进行评价.1999年,我们在波兰东南部的Bieszczady山脉开展本研究.使用1998年的陆地卫星TM数据,利用景观元素的粒度(田地大小)和土地覆盖组成(灌木和森林的扩侵)对代表真实村庄结构形态退化不同阶段的6种类型村庄进行定量描述.我们利用历史地图勾勒出村庄的边界,并测量从前森林和空地的范围.利用卫星数据,将当前的土地利用和表示成粒度及森林的扩侵状况的土地废弃程度绘制成图.退化沿着2条变化路径发生:被废弃并且最终变成森林,或者形成集约农业.为了验证这样的结果,我们通过对原始卫星影像的目视解译,将1000km2范围内的22个其他村庄分成了4类.而后,我们收集了过去60年人口变化的历史数据.村庄真实形态的分类与人口下降速度明显相关.我们希望验证和应用这种快速评估文化景观真实形态的方法能够得到重视,尤其是在随着欧盟的扩大正在经历或者将要发生巨大变化的欧洲区域.最后,我们论证了村庄具有成为一个融合自然与社会科学的景观尺度的可能性.     

Diffusive sampling of methyl isocyanate using 4-nitro-7-piperazinobenzo-2-oxa-1,3-diazole (NBDPZ) as derivatizing agent

A diffusive sampling method for the determination of methyl isocyanate (MIC) in air is introduced. MIC is collected using a glass fiber filter impregnated with 4-nitro-7-piperazinobenzo-2-oxa-1,3-diazole (NBDPZ). The urea derivative formed is desorbed from the filter with acetonitrile and analyzed by means of high-performance liquid chromatography (HPLC) using fluorescence detection (FLD) with lambdaex = 471 nm and lambdaex = 540 nm. Additionally, a method was developed using tandem mass spectrometric (MS-MS) detection, which was performed as selected reaction monitoring (SRM) on the transition [MIC-NBDPZ + H]+ (m/z 307) to [NBDPZ + H]+ (m/z 250). The diffusive sampler was tested with MIC concentrations between 1 and 35 microg m(-3). The sampling periods varied from 15 min to 8 h, and the relative humidity (RH) was set from 20% up to 80%. The sampling rate for all 15 min experiments was determined to be 15.0 mL min(-1) (using HPLC-FLD) with a relative standard deviation of 9.9% for 56 experiments. At 80% RH, only 15 min sampling gave acceptable results. Further experiments revealed that humidity did not affect the MIC derivative but the reagent on the filter prior to and during sampling. The sampling rate for all experiments (including long term sampling) performed at 20% RH was found to be 15.0 mL min(-1) with a relative standard deviation of 6.3% (N = 42). The limit of quantification was 3 microg m(-3) (LC-MS-MS: 1.3 microg m(-3)) for 15 min sampling periods and 0.2 microg m(-3) (LC-MS-MS: 0.15 microg m(-3)) for 8 h sampling runs applying fluorescence detection.     

Development of a diffusive sampling method for determination of methyl isocyanate in air

A diffusive sampling method for determination of methyl isocyanate in air has been developed. A glass fibre filter impregnated with 1-(2-methoxyphenyl)piperazine in a commercially available diffusive sampling device was used to collect methyl isocyanate and the derivative formed was analysed with LC-MS/MS. The sampling rate was determined to be 15.6 ml min(-1), with a relative standard deviation of 7.3%. The sampler was validated for sampling periods from 15 min to 8 h, for relative humidities from 20% to 80% and for concentrations from I to 46 microg m(-3). A field validation was also made and the diffusive sampling results showed no difference compared to a pumped reference method. The impregnated filters have to be stored apart from the diffusive sampler housing and loaded into the sampler prior to each sampling.     

A historical study of mineral elements in forest plants from South Norway

Herbarium plants were used as a material to study possible long-term changes in mineral elements of forest plants. Plants from South Norway collected in the period 1870 to 1930 were compared to plants collected in 1982. Relative to mineral contents in plants from 1870 to 1930, the 1982 material showed elevated levels of Zn, Cd, Rb, K, Mn and Ti and decreased levels of Sr, B, Ca and Mo in some of the plant species analysed. Most of these differences may be explained by changes in the environmental conditions, due to differences in chemical composition of precipitation, accelerated soil acidification and subsequent increasing mineral weathering. Consequently analysis of herbarium plants seems to provide valuable information about preindustrial levels of mineral elements and seems to detect changes in mineral elements brought about by recent anthropogenic activity.     

Measurements of fractionated gaseous mercury concentrations over northwestern and central Europe, 1995-99

Although it makes up only a few per cent. of total gaseous mercury (TGM) in the atmosphere, the fraction of oxidised (divalent) mercury plays a major role in the biogeochemical cycle of mercury due to its high affinity for water and surfaces. Quantitative knowledge of this fraction present in mixing ratios in the parts-per-10(15) (ppq) range is currently very scarce. This work is based on approximately 220 data for divalent gaseous mercury (DGM) collected during 1995-99 in ambient air. Over the course of the measurements, the sampling and analytical methods were modified and improved. This is described here in detail and includes transition from wet leaching and reduction procedures to thermo-reductive desorption, the use of annular as well as tubular denuders and adoption of an automated sampling system. The concentration of DGM exhibited a strong seasonal behaviour in contrast to atomic gaseous mercury, with low values in winter and maximum values in summer. The DGM/TGM ratios were frequently found to be below the detection limit (< or = 1%) and in the range 1-5%. A trend of diurnal DGM patterns was observed and implies photolytically induced sources. Scavenging of DGM during rain events was also noticed.     

科学的挑战--重视成本效益,清洁波罗的海

波罗的海是世界上受人类活动影响最严重的海洋之一,虽然有减少向波罗的海排放营养物质的国际协议,但迄今为止采取的措施,既没有从根本上减少营养物质的排放,也没有促进环境的改善.部分原因可以归咎为缺少有关物理学、生物地球化学和生态特性之间大尺度关系和相互作用的知识,但是还缺少全流域范围的成本效益分析.错误的决策非常危险,例如,执行的减少排放的方案根本没有效果,或远远达不到成本效益.许多学科的研究者正面临着一个共同的挑战开发一个决策支持系统,作为整个波罗的海成本效益分析法的科学基础.研究项目海洋富营养化的研究(MARE)(http∥www.mare.su.se)正致力于这方面的研究.     

从富营养化状态中复原：减少对瑞典四大湖磷输入的经验

自20世纪60年代以来,人们一直在研究随着输入的减少韦特恩湖、维纳恩湖、梅拉伦湖以及哈马伦湖中磷(P)和氮(N)的浓度变化.在前两个水更新速度较慢的深水、贫营养湖中,自70年代以来磷输入的急剧减少只是造成较长一段时间内磷浓度的少量减小.同时在水团中出现了非有机氮的积累现象,本文对这一现象的可能原因进行了探讨.在后两个中等营养到高营养的湖中,哈马伦湖中的两个浅盆地由于沉积物释放的氮而显示出恢复较慢.这两个盆地以及梅拉伦湖中的两个盆地有氮缺乏现象,特别是在磷输入减少之前的数年中、而且表明存在固氮现象.在梅拉伦湖的两个盆地中,湖内磷浓度的恢复与用于湖泊从营养物污染中恢复的IMSA模型相比较预期的要好.在其他的5个湖泊/盆地中,20年之后的叶绿素浓度与那些模拟的情况相比类似.     

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.     

Successful DNA-based prenatal exclusion of juvenile neuronal ceroid lipofuscinosis

A family with two siblings, 10 and 8 years old, both with clinical and ultrastructural evidence of juvenile neuronal ceroid lipofuscinosis is described. The family was found to be informative for the restriction fragment length polymorphisms (RFLPs) detected by the probes pCJ52–95Ml (locus D16S148) and pCJ52-94Tl (locus D16S159) flanking the juvenile neuronal ceroid lipofuscinosis locus, CLN3. The parents were both heterozygous using these probes, while their two children with juvenile neuronal ceroid lipofuscinosis were both homozygous. Chorionic villi analysis showed that the fetus was heterozygous and had inherited the one allele of the mother which was not found in the two siblings. This suggested that the fetus had derived one healthy allele from the mother, the risk for a double crossing-over being less than 1 per cent. Electron microscopy showed no fingerprint inclusions in chorionic villi. The child was investigated at 6 months of age and found to be healthy, as new fingerprint inclusions were found at electron microscopy and no vacuolated lymphocytes were found in the blood smear. Due to the risk of heterogeneity, both DNA-based analysis and electron microscopy on chorionic villi are recommended for prenatal examination for juvenile neuronal ceroid lipofuscinosis.