Carrier Screening for Spinal Muscular Atrophy (SMA) in 107,611 Pregnant Women during the Period 2005–2009: A Prospective Population-Based Cohort Study

BACKGROUND: Spinal muscular atrophy (SMA) is the most common neuromuscular autosomal recessive disorder. The American College of Medical Genetics has recently recommended routine carrier screening for SMA because of the high carrier frequency (1 in 25-50) as well as the severity of that genetic disease. Large studies are needed to determine the feasibility, benefits, and costs of such a program. METHODS AND FINDINGS: This is a prospective population-based cohort study of 107,611 pregnant women from 25 counties in Taiwan conducted during the period January 2005 to June 2009. A three-stage screening program was used: (1) pregnant women were tested for SMA heterozygosity; (2) if the mother was determined to be heterozygous for SMA (carrier status), the paternal partner was then tested; (3) if both partners were SMA carriers, prenatal diagnostic testing was performed. During the study period, a total of 2,262 SMA carriers with one copy of the SMN1 gene were identified among the 107,611 pregnant women that were screened. The carrier rate was approximately 1 in 48 (2.10%). The negative predictive value of DHPLC coupled with MLPA was 99.87%. The combined method could detect approximately 94% of carriers because most of the cases resulted from a common single deletion event. In addition, 2,038 spouses were determined to be SMA carriers. Among those individuals, 47 couples were determined to be at high risk for having offspring with SMA. Prenatal diagnostic testing was performed in 43 pregnant women (91.49%) and SMA was diagnosed in 12 (27.91%) fetuses. The prevalence of SMA in our population was 1 in 8,968. CONCLUSION: The main benefit of SMA carrier screening is to reduce the burden associated with giving birth to an affected child. In this study, we determined the carrier frequency and genetic risk and provided carrier couples with genetic services, knowledge, and genetic counseling

Curing simulation of composites coupled with infrared heating

International audienceBecause of higher specific strength and stiffness, low weight, and good resistance to corrosion, the use of composite materials in aerospace structures has increased. Aircraft industry has recently begun to investigate Liquid Composites Molding techniques (LCM) through research programs because of its ability to produce large parts at a low cost. In this paper, we have not addressed the filling step during which the resin flows through fibrous media, but we investigate the numerical simulation of curing reinforced RTM-6 by infrared heating. A ray tracing in-lab software called RAY-HEAT is used to compute the radiation energy due to the interaction between reinforced RTM-6 and lamps. Finite element based program COMSOL Multiphysics™ has been used to simulate the curing process. Thermochemical model has been implemented in order to compute reaction rate as a function of reaction temperature and degree of conversion using a cure kinetic model

Biomass characteristics, aeration and oxygen transfer in membrane bioreactors: their interrelations explained by a review of aerobic biological processes

Membrane bioreactor (MBR) is a promising alternative to conventional wastewater treatment methods. However this process is still under-used due to its high running costs. Its main power requirement comes from aeration, which is used to supply dissolved oxygen to the micro-organisms and to maintain the solids in suspension. In addition, in submerged MBRs, aeration is used for membrane cleaning. A complex matrix links the biomass characteristics, the aeration and the oxygen transfer. These parameters can impact on each other and/or delete one another effect. In order to understand the phenomena occurring in MBRs, similar aerobic biological processes, such as fermentation, mineral industry and slurry, were investigated. This review discusses the interrelations of the biomass characteristics (solids concentration, particle size and viscosity), the aeration intensity and the oxygen transfer in MBRs