S-100 protein and neuron-specific enolase in amniotic fluid as markers of abdominal wall and neural tube defects in the fetus

The aim of this study was to determine whether there is increased leakage of neuron-specific enolase (NSE) and S-100 protein into amniotic fluid in pregnancies with neural tube defects, since both these proteins are produced by neural tissue, and to compare the value of these substances for detecting such defects with that of the more conventional techniques of alpha-fetoprotein (AFP) and acetylcholinesterase (AChE) gel electrophoresis. Amniotic samples from 25 mid-pregnancies (15–17 weeks' gestation) with neural tube defects (14 with open spina bifida and 11 with anencephaly) and from seven mid-pregnancies with abdominal wall defects were compared with a control material consisting of 80 amniotic fluid samples from 80 consecutive mid-pregnancy amniocenteses, with normal karyotypes and AFP concentrations. All of the above cases of abnormalities were primarily detected through increased AFP levels in the amniotic fluid. Amniotic fluid samples from 13 pregnancies with fetuses with autosomal chromosomal abnormalities and seven amniotic fluid samples contaminated with blood were also included in the investigation. It is concluded from the results that the conventional AFP assay combined with AChE gel electrophoresis is the best method for screening amniotic fluid for neural tube defects and defects of the abdominal wall. Neither NSE nor S-100 assay alone proved to be superior for the detection of these cases in mid-trimester amniotic fluid. The S-100 assay, however, could give additional information in cases where AChE gel electrophoresis is not decisive; for example, in samples contaminated with blood.     

莫桑比克伊尼亚卡岛的珊瑚礁生长:珊瑚群落与1999/2000年南部非洲洪水对其造成的影响

引言 在过去几十年中进行的调查工作使我们对低纬度珊瑚礁的生长有了较清楚的认识.生长在这些环境(往往在温度、盐度和光照方面处于理想的条件下)中的珊瑚虫能够形成在空间上非常重要的珊瑚礁结构.在清澈的水体中,水下100m多的地方都有珊瑚生长[1,2],但据报道,在较浅的地方,碳酸盐净累积速度为0.83～0.91kg CaCO3/m2@a[3,4].     

Profitability of intensification technologies among smallholder maize farmers in the forest-savanna transition zone of Nigeria

Sustaining the productive capacity of the land resource under the existing land-use system and increasing population pressure requires the use of appropriate technologies that will enhance farm productivity and income levels.This paper examines the effect on farm profitability of smallholder maize farmers’ use of intensification technologies in tropical agriculture. The survey was conducted in southwest Nigeria. A multi-stage sampling technique was used to select 300 respondents from two major agroclimatic zones in Osun State. Primary data were collected using a structured questionnaire and complemented with focus group discussions (FGDs), while the State’s Ministry of Agriculture provided secondary data.Pressure on land was found high because farmland was continuously cropped for an average of 10 years with a mean fallow period of 2 years only. Technologies used to intensify agriculture included inorganic fertilizer, organic manure, alley cropping, and tree planting.Results from costs and returns analysis showed that average net returns to inorganic fertilizer use ranked highest in the two zones, while tree planting ranked lowest. There was a significant ecoregional difference on the average net returns/year earned by users of mineral fertilizer. While organic manure use earned higher net returns than alley cropping practice in the rain forest, the reverse was the case for the derived savanna. FGDs revealed that respondents’ preferred to use inorganic fertilizer despite its inadequate supply because, apart from enhancing higher returns and net gains, it also improved output level and provided an opportunity for the continuous use of the scarce land.These results imply that economic returns play a critical role in farmers’ use of intensification technologies and consequently affect their resource management decisions. Policy measures aimed at promoting research on appropriate technologies that are profitable on farmers’ fields will be more effective in enhancing farmers’ use of intensification technologies.     

Vocal acrobatics in a Chinese frog, <Emphasis Type="Italic">Amolops tormotus</Emphasis>

Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x.     

Influence of conservation tillage on winter bird use of arable fields in Hungary

Bird use of conservation tillage-established (CT—seedbed preparation without soil inversion) crops was assessed at two adjacent sites in western Hungary, in comparison with conventionally established (mouldboard ploughed—P) fields. Bird abundance was assessed in a typical rotation of spring-sown maize and winter wheat in three consecutive winters. In the first winter, several species and the guild of seed-eating passerines were significantly more abundant on CT established plots, in both crop types. In the second winter, only starlings were more abundant on CT plots. In the third winter, only skylarks favoured CT over P plots. In combination with agri-environment scheme measures designed to provide resources for biodiversity, conservation tillage could play a role in softening the impact of agriculture on farmland birds in Hungary and elsewhere in Eastern Europe, in addition to its potential for reducing soil erosion and diffuse pollution.     

Climate anomalies, Indonesian vegetation fires and terrestrial carbon emissions

There was a widespread misconception about the causes of vegetation and land fires in Indonesia. At a certain point, the public perceived that fires and the associated haze pollution were primarily caused by smallholders' agricultural activities. In fact, there was a variety of land-use activities including large-scale land clearing following deforestation for further land development. El Niño events and the associated dry weather were sometimes quoted by officials and the media as the cause of fires. The fire episodes from 1980 to 2000 were analysed in connection with climate anomalies and the implementation of land-use policies related to forest conversions. The analysis employs long-term climatic and sea surface temperature data to reconstruct climate distributions and anomalies including Southern Oscillation Index (SOI), Sea Surface Temperature (SST) and Outgoing Long-wave Radiation (OLR). In this study, the terrestrial carbon emissions from vegetation fires were estimated based on official statistical data on area burnt. The possible incentives for sustainable land management were discussed in the light of fire prevention. The underlying cause neglected in the discussion of Indonesian vegetation fires was forest and land development policy. Legitimated in the early 1980s, it drove massive forest conversions and the use of fires for land clearing. El Niño Southern Oscillation (ENSO) provided dry weather suitable for biomass burning and widespread fire, but it was hardly the cause of fires. The estimate of area burnt in the big fires in 1997 was about 11.6 Mha, resulting in carbon release of 1.45 Gt, equivalent to 0.73 ppmv of CO₂, or almost half the annual global atmospheric CO₂ growth. Based on the current carbon market price such emissions by the 1997 fire episode were worth around US$ 3.6 billion.     

中国、印度和世界的新秩序

中国和印度几乎同时出现在世界舞台表明国际事务的架构发生了史无前例的变化.这两个占世界人口40%的巨人,其人口相当于位居其后的20个人口最多国家的人口总和.在十九和二十世纪,这两个巨人长期在主宰国际事务的欧洲、日本和美国的阴影之下沉睡.     

丁基锡化合物在水体悬浮颗粒物上的吸附行为研究

将海河河口表层底泥制成悬浮颗粒物（ＳＰＭ），采用批量平衡法首次研究了模拟河口条件下三丁基锡（ＴＢＴ）和二丁基锡（ＤＢＴ）在该ＳＰＭ上的吸附行为．结果表明，ＴＢＴ和ＤＢＴ均能在ＳＰＭ上发生吸附，尤以ＴＢＴ更为显著．吸附速率可用Ｋｕｏ和Ｌａｋｅ的经验公式描述；吸附过程受ＳＰＭ的浓度及ＴＯＣ含量、ｐＨ值、温度、腐殖酸浓度和盐度影响．实际河口水样中的ＳＰＭ对ＴＢＴ和ＤＢＴ的吸附百分率也较高，因此ＳＰＭ是ＴＢＴ和ＤＢＴ归趋的重要场所，去除ＳＰＭ可使水体得到一定净化．     

Greenhouse Gas Inventory for Land Use Change and Forestry in Finland Based on International Guidelines

Mitigation and Adaptation Strategies for Global Change - Guidelines of the Intergovernmental Panel on Climate Change (IPCC) were used to assess a greenhouse gas inventory for land use change and...