Human Settlements on the Northern Shores of Lake Aral and Water Level Changes

The shore of Lake Aral in Kazakhstan is a perfect area for studying the human adaptation strategy to past climate changes. New archaeological material, gathered along the northern shores during the expedition of the INTAS project CLIMAN, is briefly presented. Changes in settlement activity during the Atlantic and Subboreal are related to lake level changes of the Aral Sea. A previ-ously proposed lake level maximum needs to be revised. In particular the lake level stand at 72/73 m, with an assumed age of 5000 BP is definitely refused. Based on the presented data the maximum lake level most probably never reached beyond 57/58 mean average sea level (masl). Furthermore the regression during the 15^th–16^th centuries has been underestimated. It may have been lower than the present day level. Thus the present desiccation of the Aral Sea is historically not unique, as a similar regression, probably induced by man as well, has occurred at least once during history. A readjustment of the water level is, therefore, possible at any time.     

Second-trimester maternal serum screening using alpha-fetoprotein,human chorionic gonadotrophin,and unconjugated oestriol: Experience of a regional programme

Over a 2-year period from January 1991 to December 1992, second-trimester maternal serum screening for Down's syndrome using alpha-fetoprotein (aFP), human chorionic gonadotrophin (hCG), and unconjugated oestriol (uE₃) was made available to five health districts in East Anglia, with a total population of 1·2 million. Amniocentesis was offered when the risk of Down's syndrome at term was 1:200 or greater. 25359 singleton pregnancies were screened, representing an uptake of 77 per cent. The recall rate for the 24 per cent of women who had not had a dating scan prior to the test was 9·4 per cent compared with 3·9 per cent for those who had been scanned (P<0·0005). Seventy-five per cent (36/48) of Down's syndrome pregnancies were detected for a false-positive rate of 4·0 per cent. Twenty-five out of 36 of detected Down's syndrome pregnancies were dated by scan prior to sampling, and in the 11 remaining cases, the dates were confirmed by scan after a high-risk result was obtained. The exclusion of uE₃ from the screening protocol would have reduced the detection rate to 52 per cent (25/48) for the same false-positive rate. Eighty-five per cent of women identified at high risk accepted the offer of an amniocentesis. Other fetal abnormalities detected were trisomy 18 (3), trisomy 13 (2), 45,X (6), 69,XXX (5), other chromosome abnormalities (9), open neural tube defects (26), hydrocephalus (7), abdominal wall defects (4), and steroid sulphatase deficiency (6).     

First-trimester diagnosis of Meckel–Gruber syndrome by transabdominal sonography in a low-risk case

Meckel–Gruber syndrome is a rare autosomal recessive disorder often resulting in neonatal death within a few hours of life. The condition is usually diagnosed ultrasonographically in the second trimester and earlier diagnosis has been mainly confined to high recurrence risk pregnancies. We describe the earliest non-invasive diagnosis of this condition at 12⁺² weeks' gestation in a patient with no previous history using transabdominal ultrasound. Pregnancy termination was declined. Subsequent development of anhydramnios in the mid-trimester resulted in poor fetal visualization. We propose that first-trimester diagnosis of this condition is not only possible but preferable, as normal liquor volume facilitates visualization of fetal anatomy.     

地下水中汞的形成及其与人群健康的关系

地下水中汞元素的形成，主要是含汞矿物岩土溶解作用的结果，但其含量一般很低。汞与人体关系密切，结肠癌、肺癌死亡率与土壤中汞含量呈正相关，胃癌死亡率则与汞元素含量呈负相关。地下水汞元素含量小于１μｇ／Ｌ时，不会对人体健康产生危害。     

Prenatal diagnosis of Pallister–Killian syndrome: Resolution of cytogenetic ambiguity by use of fluorescent in situ hybridization

We report a case of Pallister-Killian syndrome initially diagnosed prenatally as tetrasomy 21. A 33-year-old primiparous woman was noted at 24 weeks' gestation to have moderate polyhydramnios. Ultrasonography showed diminished fetal stomach filling, hydronephrosis, and prominence of the cisterna magna. Cytogenetic analysis of cultured amniocytes was initially interpreted as mosaic tetrasomy 21: 46,XX/47,XX,+i(21q). The patient was then referred to our centre for genetic counselling. At 34 weeks' gestation, a dysmorphic infant was delivered and died within 30 min. Physical features were consistent with the Pallister-Killian syndrome. Renal, gastrointestinal, and central nervous system anomalies were found at post-mortem examination. Analysis of peripheral lymphocytes revealed 5 per cent of cells with a marker chromosome, while 92 per cent of cultured fibroblasts had this same marker. Fluorescent in situ hybridization (FISH) using an alpha-satellite probe for chromosomes 13 and 21 failed to hybridize to the marker, while a chromosome 12 centromeric probe unequivocally identified it as an i(12p). Use of FISH can provide rapid, specific prenatal diagnosis of ambiguous marker chromosomes and improve prenatal counselling.     

青浦区城市化中人居环境的协调发展研究

青浦区人居环境的可持续发展体系是一个由人口、社会、资源、环境与经济5个子系统构成的开放巨系统。文章通过提出综合衡量系统“协调性”和“发展水平”的“协调发展度”模型，研究青浦区在城市化中人居环境复合系统内5个子系统之间协调发展度情况。并运用回归模型，探讨协调发展度与城市化发展水平之间的内在联系，提出城市化进程必须与其人居环境的可持续发展相适应。     

Increased maternal serum alpha-fetoprotein and human chorionic gonadotropin in compromised pregnancies other than for neural tube defects or Down syndrome

Intrauterine fetal death occurred in four women who were ‘screen-positive’ in a screening programme for neural tube defects (NTDs) and Down syndrome (DS). These women had very high levels of maternal serum alpha-fetoprotein (MSAFP) and maternal serum human chorionic gonadotropin (MShCG). Therefore, we evaluated all ‘screen-positive’ women in whom both of these markers were ⩾ 2.0 multiples of the median. The cases fulfilling these criteria totalled 11, and only one of them had no complications. High concentrations of both MSAFP and MShCG in a number of these cases might have been caused by an increased placental volume, which, in turn, might have been induced by decreased perfusion of the placenta. We conclude that screening programmes wrongly determine a high risk of fetal NTD or DS if the concentrations of both these parameters are very high. Invasive diagnostic procedures should be avoided in these cases, particularly in view of the increased risk of an adverse pregnancy outcome.     

高校主体性人力资源职业生涯发展管理研究

本文深入探讨了高校主体性人力资源的特点及其职业生涯发展的主要特征，针对高校当前在职业生涯发展管理上存在的主要问题，提出了进行管理创新的几个基础性工作，为全面有效地进行职业生涯发展管理奠定坚实的基础．     

人为活动影响下的生态系统反馈机制--塔里木河流域生态输水工程的效应分析

通过对塔里木河流域生态输水工程的效应分析,揭示了生态系统反馈机制的原理和特点,强调了负反馈机制的作用,即生态系统在受到外界影响或干扰后,通过一系列的自我调节功能来减轻这种干扰或影响的程度,并力图恢复到平衡或稳定状态.最后,探讨了生态系统反馈机制的作用和意义.     

Natural pollution caused by the extremely acidic crater lake Kawah Ijen, East Java, Indonesia

Background. Aims and Scope Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH 〈 0.3. It is the source of the extremely acid and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. Methods Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. Results and Discussion The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980 – 2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1600 mg/l) and aluminium (up to 3000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acid water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acid irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents” diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. Conclusions, Recommendations and Outlook In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.