Prenatal diagnosis using deletion studies in Duchenne muscular dystrophy

Accurate carrier testing and prenatal diagnosis in Duchenne muscular dystrophy (DMD) families is facilitated when an Xp21 deletion is found to be segregating within a family. We discuss the results of the DNA testing in two families, one in which DNA from affected males was available for study and the other in which no DNA from an affected male was available. Factors complicating the counselling of DMD deletion families are outlined.     

Cystic hygroma: Prenatal diagnosis and genetic counselling

Six cases of cystic hygromas detected during second trimester ultrasound examination are reported: 4 fetuses (67 per cent) had a 45, X karyotype, 1 fetus had trisomy 18, 1 fetus had a normal karyotype (46,XX) and at autopsy multiple anomalies were observed. In the latter case the family history suggested an autosomal recessive pattern of inheritance. In order to reach a definite diagnosis and give proper genetic counselling when a fetus is found to have cystic hygroma, a fetal karyotype as well as a family and reproductive history should be obtained.     

喷射成形制造工艺

喷射成形是一种先进的材料制备技术,该技术具有近终形制造的特点,近年来已广泛应用于研究和开发多种高性能快速凝固材料.文中介绍了喷射成形工艺过程、特点,并回顾了喷射成形工艺的发展历程及现在所达到的技术水平.     

DNA-based carrier detection and prenatal diagnosis of tyrosinase-negative oculocutaneous albinism (OCA1A)

We describe molecular prenatal diagnosis and carrier detection of tyrosinase-negative oculocutaneous albinism (OCA1A) in two families. In one family, we carried out DNA-based prenatal diagnosis of OCA1A. In the other family, mutation analysis and carrier detection obviated the need for prenatal diagnosis. Molecular analysis is safer and probably more accurate than fetoscopy and fetal scalp biopsy, and should become the method of first choice for prenatal diagnosis of OCA1.     

一株硝基苯高效降解菌的筛选及其降解特性

自南京化工厂下水道底泥和废水处理系统曝气池活性污泥中驯化分离得到一株能快速降解硝基苯的菌株,初步鉴定其为不动杆菌属菌株。该菌株降解硝基苯的最适宜环境条件为温度25℃～35℃,pH7～8,振荡速率大于120r/m。在适宜环境条件下,该菌株能够在24h内全部降解初始浓度不超过400mg/L的硝基苯,该浓度范围内硝基苯的降解过程符合零级动力学特征;当硝基苯的初始浓度超过400mg/L时,降解菌的生长受到毒害作用,该浓度范围内硝基苯的降解在开始有一个明显的停滞期,降解过程不再符合零级或一级动力学特征。     

Intertemporal and intergenerational pareto efficiency: A comment

In a recent issue of this Journal, Sandler and Smith developed an analysis from which they concluded that discounting is Pareto inefficient in an intertemporal context. This comment questions the validity of that conclusion and demonstrates the essential role played by the discount rate in achieving intertemporal Pareto efficiency within a market economy.     

Mobility control: How injected surfactants and biostimulants may be forced into low‐permeability units

Recovering dense nonaqueous‐phase liquid (DNAPL) remains one of the most difficult problems facing the remediation industry. Still, the most common method of recovering DNAPL is to physically remove the contaminants using common technologies such as total fluids recovery pumps, vacuum systems, and “pump‐and‐treat.” Increased DNAPL removal can be attained using surfactants to mobilize and/or solubilize the pollutants. However, very little is understood of the methods developed by petroleum engineers beginning in the 1960s to overcome by‐passed, low‐permeability zones in heterogeneous oil reservoirs. By injecting or causing the formation of viscous fluids in the subsurface, petroleum engineers caused increased in‐situ pressures that forced fluid flow into low permeability units as well as the higher permeability thief zones. Polymer flooding involves injecting a viscous aqueous polymer solution into the contaminated aquifer. Foam flooding involves injecting surfactant to decontaminate the high‐permeability zones and then periodic pulses of air to cause a temporary viscous foam to form in the high‐permeable zones after all DNAPL is removed. Later surfactant pulses are directed by the foam into unswept low‐permeable units. These methods have been applied to DNAPL removal using surfactants but they can also be applied to the injection of bio‐amendments into low‐permeability zones still requiring continued remediation. Here we discuss the principles of mobility control as practiced in an alluvial aquifer contaminated with chlorinated solvent and coal tar DNAPLs as well as some field results. © 2003 Wiley Periodicals, Inc.     

An Application of a Modified Ecological Footprint Method and Structural Path Analysis in a Comparative Institutional Study

This paper presents an application of a modified ecological footprint method, using a regional, disturbance-based approach. In contrast to conventional institutional ecological footprint calculations, energy and land use resulting from all upstream production processes are explored by employing an input-output framework. Ecological footprints are calculated for two research institutions: the School of Physics (SoP) at the University of Sydney, and the Sustainable Ecosystems (CSE) Department of the Commonwealth Scientific and Industrial Research Organisation. These are broken down further in terms of land disturbance and greenhouse gas emissions, and as a function of production layer. To enable the use of the results in policy formulation, the ecological footprints are decomposed into detailed contributing paths, which are ranked according to their importance, using structural path analysis. The paper demonstrates that a considerable proportion of impacts occur upstream in industrial production. Thus a significant result of the study is the weight of obscure paths in the total footprints and, therefore, the importance of conducting an holistic assessment in order to ensure all upstream contributions are captured in the final impact of the institution.