“三软”煤层综放工作面综合防尘技术试验研究

以典型工作面为例研究了煤体注水、自动喷雾、磁化水喷雾、化学防尘等综合防尘技术在“三软”煤层综采放顶煤工作面的实施方法,并对应用中遇到的一些理论问题进行了探讨     

Antenatal detection of neural tube defects: Comparison of biochemical and immunofluorescence methods

The aim of this study was to determine whether identification of glial cells in amniotic fluid samples could form a useful supplementary test in the antenatal diagnosis of neural tube defects (NTDs). In a 5-year study, 1452 samples of middle trimester amniotic fluid were examined blind to the results of other antenatal diagnostic tests and to the outcome of pregnancy. Reasons for amniocentesis included raised serum alpha-fetoprotein (329), previous NTD (73), and a family history of NTDs (71). Duplicate cytospin preparations were stained with Giemsa and an antibody to glial fibrillary acidic protein (GFAP), and on this basis a prediction of fetal NTD status was made which was not communicated to clinicians. Subsequent management of pregnancies was influenced only by the results of routine antenatal testing for NTDs. Twenty cases of NTDs occurred among the 1406 cases in which the outcome was subsequently known. Of these 20 cases, only five (four anencephalic, one spina bifida) were correctly predicted by immunofluorescent identification of GFAP-positive cells in the amniotic fluid. The remaining 15 cases (two anencephalic, 13 spina bifida) were not so identified. In a further 18 cases, apparently GFAP-positive cells were identified in the absence of NTDs. We conclude that GFAP immunofluorescence examination of routine amniocentesis samples of amniotic fluid is not a useful predictive test for NTDs.     

Successful outcome of pregnancy after treatment of maternal anti-ro (SSA) antibodies with immunosuppressive therapy and plasmapheresis

In this short communication we describe a patient with anti-SSA and anti-SSB antibodies whose first child died of congenital complete heart block (CCHB). During her second pregnancy she was treated with prednisolone, azathioprine, and plasmapheresis, and levels of anti-SSA and anti-SSB antibodies fell significantly. The pregnancy evolved uneventfully and resulted in the birth of an unaffected male infant. This is the fourth reported case of a successful outcome of pregnancy after treatment with immunosuppressive drugs in a woman with a significant risk of recurrence of CCHB.     

Maternal investment and sex-allocation in the Galapagos fur seal,Arctocephalus galapagoensis

Summary Maternal investment and sex-allocation were measured in a large, sexually dimorphic mammal, the Galapagos fur seal (Arctocephalus galapagoensis). The sex ratio at birth was 1.06. Males were always heavier than females and, at least initially, grew faster. Growth was variable from year to year suggesting energetic constraints on maternal investment. Sucking time conrrelated with milk intake. Mothers suckled yearling and 2-year-old sons more than daughters of the same age. Age at weaning appeared to be the same in both sexes or even slightly greater in males. No sex differences was found in mortality prior to weaning or in post-weaning dispersal. Birth rates of females with yearlings or 2-year-olds were significantly lower than those of females with no dependent young. Mothers invested more in sons than in daughters until weaning. It is unlikely that higher post-weaning investment in daughters balances the higher pre-weaning investment in sons. Data on sex ratio at birth, different growth rates, and weaning age of the sexes are typical of otariid seals as a group. The results of this study fit Maynard Smith's (1980) model of the evolution of sex allocation better than Fisher's (1930).     

New estimates of down syndrome risks at chorionic villus sampling,amniocentesis, and livebirth in women of advanced maternal age from a uniquely defined population

Current measures of livebirth prevalence of Down syndrome are derived from data obtained up to 20 years ago, before the introduction of the prenatal diagnostic tests amniocentesis and chorionic villus sampling (CVS). For women aged 36–52 years, but who were not tested prenatally, we proposed to make a direct estimate of current livebirth prevalence of Down syndrome. We could also determine prevalence at the time of CVS and amniocentesis in women of the same age undergoing prenatal testing. Differences in these prevalences allow an estimation of the relative loss of Down syndrome during pregnancy. In Victoria, Australia, we identified 3041 women having CVS, 7504 having amniocentesis, and 13 139 having no test. Smoothed regression estimates of age-specific livebirth prevalence were found to be higher than in the early studies. The estimate of spontaneous loss was 17 per cent between the time of CVS and amniocentesis, and 18 per cent after the time of amniocentesis. The latter figure is lower than previous estimates and may be explained by a greater likelihood of a Down syndrome fetus surviving to be liveborn, given the modern approach to early obstetric intervention. These current risk estimates of livebirth may be useful updates for genetic counselling, but perhaps more importantly, may be used as precise maternal age-related risk figures, necessary in the design and implementation of prenatal screening programmes for Down syndrome.     

Provincial development plans in Zimbabwe: an analysis of their content,structure and methodology

Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.

This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal.