Mouse Staufen (mStau) is a double-stranded RNA-binding protein associated with polysomes and the rough endoplasmic reticulum (RER). We describe a novel endogenous isoform of mStau (termed mStau i ) which has an insertion of six amino acids within dsRBD3, the major double-stranded RNA (dsRNA)-binding domain. With a structural change of the RNA-binding domain, this conserved and widely distributed isoform showed strongly impaired dsRNA-binding ability. In transfected cells, mStau i exhibited the same tubulovesicular distribution (RER) as mStau when weakly expressed; however, when overexpressed, mStau i was found in large cytoplasmic granules. Markers of the RER colocalized with mStau i -containing granules, showing that overexpressed mStau i could still be associated with the RER. Cotransfection of mStau i with mStau relocalized overexpressed mStau i to the reticular RER, suggesting that they can form a complex on the RER and that a balance between these isoforms is important to achieve proper localization. Coimmunoprecipitation demonstrated that the two mStau isoforms are components of the same complex in vivo. Analysis of the immunoprecipitates showed that mStau is a component of an RNA-protein complex and that the association with mStau i drastically reduces the RNA content of the complex. We propose that this new isoform, by forming a multiple-isoform complex, regulates the amount of RNA in mStau complexes in mammalian cells.RNA transport and localization provide an efficient way to distribute genetic information and to allow different portions of the cell to establish their own biochemical fates (12,20,32,44). Examples of this process have been described in many different organisms and cell types. RNA localization and/or localized translation are linked to different biological processes such as asymmetric cell division (7, 28, 39, 45), long-term potentiation (30), synaptic transmission (40), cell motility (23), and axis formation in oocytes (44). It is now apparent that many determinants of RNA localization are conserved among these systems. The process of mRNA localization is initiated by association of RNA with one or more RNA-binding proteins (RBPs) through a targeting signal most commonly located in the 3Ј untranslated region (3Ј UTR) of the transcripts. This association results in the formation of large ribonucleoprotein complexes (RNPs) (1, 13, 24). These complexes then migrate along the cytoskeleton to their final destination, where they are anchored and translated. For the entire localization process, translation of localized mRNAs needs to be tightly regulated. Specific signals are important for repressing translation during mRNA transport and derepressing translation once RNPs are properly localized (15,21,22). The crucial role played by the cytoskeleton in many steps of transport, anchoring, and translation (2, 34, 41, 47) is another feature which appears to be conserved in numerous RNA localization systems. The multistep process of RNA localization is dependent on specific trans-acting proteins. T...

No abstract

Background:Obesity has become a major health problem among children and adolescents worldwide. This study aimed to examine the trends of overweight and obesity among childhood in China and assess their associations with family income, dietary intake, and physical activity (PA) between 1997 and 2009.Methods:Two waves of cross-sectional data of Chinese children and adolescents aged 7–17 years from the China Health and Nutrition Survey were used. Weight and height were measured following standardized procedures. Dietary intake was assessed by 3 consecutive 24-h recalls. Childhood overweight and obesity were defined using the International Obesity Task Force-recommended body mass index cut-offs. Multivariate linear regression analysis was used to examine the associations of family income with diet intakes and PA. Multivariate logistic regression analysis was conducted to assess the associations of overweight and obesity with family income, dietary intake, and PA.Results:The prevalence of childhood overweight and obesity increased from 12.6% in 1997 to 22.1% in 2009, particularly in the medium- and high-family income groups, which increased by 102.7% and 90.3%, respectively. Higher fat intake (% energy), and moderate and vigorous PA were significantly associated with overweight and obesity in final model (odds ratio [OR] = 1.01, 95% confidence interval [CI]: 1.00–1.02, P = 0.004; and OR = 0.99, 95% CI: 0.98–1.00, P = 0.036, respectively).Conclusions:The prevalence of overweight and obesity among Chinese children and adolescents has increased between 1997 and 2009. Reducing fat intake and increasing PA may help obesity prevention.

The paper presents a newly developed optical polishing method, Ultrasonic-magnetorheological compound finishing (UMC finishing). The mechanism of UMC finishing is introduced in the paper. Experiments are carried out to study the surface quality of the optical glass K9 in UMC finishing. The result shows that the surface roughness Ra of the optical glass is 4.0nm, which is measured by the profile meter. The rules of surface roughness for optical glass by the main processing parameters are also acquired by the experiments. The study will be the basis for the further study of UMC finishing technology.

Based on double Epstein frame measurement method, double Epstein frame measurement experiments are carried out for 30P120 silicon steel samples using two pairs of Epstein frames (namely 2E (25-20) and 2E (20-17.5)) magnetic measuring devices, to study factors affecting the mean path length of the Epstein frame. 3D simulation proves the preconditions of double Epstein frame method, that is equivalent magnetic flux density of corresponding corner positions. On this basis, a weighted processing method is proposed to determine the effective path length of standard 25cm Epstein frame and to compare with that of double Epstein frame method, which processes the mean path length determined by the different specific losses of the Epstein frame (i.e., the uniform areas, the corner areas and the impact zones between them of the whole Epstein frame). Not only the method excludes the effect of the magnetic characteristics inhomogeneity of samples in the corner double-lapped structure areas, but also considers the influence of the specific power losses in the different parts determining the mean path length. The obtained experimental results confirm the correctness of the method in this paper for determining the specific total loss of electrical steel sheet.