Uptake and utilization of mRNA by myogenic cells in culture

Primary chick myoblast cultures demonstrate the ability to take up exogenously supplied polyadenylated RNA and express the encoded information in a specific manner. This expression is shown to exhibit tissue specificity. Analysis of creatine kinase activity monitored at various times of incubation in the presence of either polyadenylated or nonpolyadenylated RNA indicates that only the poly(A)+ mRNA is capable of being actively translated. Radioactively labled poly(A)+ mRNA is taken up by the cell cultures in a time-dependent manner and subsequently shown to be associated with polysomes. This association with polysomes does not occur in the presence of puromycin and is unaffected by actinomycin D. Thus, nonspecific interaction with polysomes and induction of new RNA synthesis are ruled out and the association of the exogenously supplied poly(A)+ mRNA with polysomes is indicative of its translation in the recipient cells. When heterologous mRNA (globin) is supplied to the myoblasts, it is also taken up and properly translated. In addition, exogenously supplied myosin heavy chain mRNA is found associated with polysomes consisting of 4-10 ribosomes in myoblast cell cultures while in myotubes it is associated with very large polysomes, thus reflecting the different translational efficiencies that this message exhibits at two very different stages of myogenesis. The results indicate that muscle cell cultures can serve as an in vitro system to study translational controls and their roles in development.     

Implosive therapy treatment of heroin addicts during methadone detoxification.

Examined the effectiveness of implosive therapy with heroin addicts during detoxification from methadone. 24 Ss with comparable histories of heroin addicition and similar maintenance levels of methadone were assigned to an implosive therapy, eclectic counseling, or control group. The 2 treatment groups received 12 sessions of implosive therapy or eclectic counseling and were followed for a subsequent 6-wk period. The implosive therapy Ss were the only ones to reduce significantly their methadone level during treatment and the follow-up period. (1 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reducing the fuel use and greenhouse gas emissions of the US vehicle fleet

The unrelenting increase in the consumption of oil in the US light-duty vehicle fleet (cars and light trucks) presents an extremely challenging energy and environmental problem. A variety of propulsion technologies and fuels have the promise to reduce petroleum use and greenhouse gas emissions from motor vehicles. Even so, achieving a noticeable reduction on both fronts in the near term will require rapid penetration of these technologies into the vehicle fleet, and not all alternatives can meet both objectives simultaneously. Placing a much greater emphasis on reducing fuel consumption rather than improving vehicle performance can greatly reduce the required market penetration rates. Addressing the vehicle performance–size–fuel consumption trade-off should be the priority for policymakers rather than promoting specific vehicle technologies and fuels.     

UV Microstereolithography System that uses Spatial Light Modulator Technology

A new stereophotolithography technique utilizing a spatial light modulator (SLM) to create three-dimensional components with a planar, layer-by-layer process of exposure is described. With this procedure it is possible to build components with dimensions in the range of 50 mum-50 mm and feature sizes as small as 5 mum with a resolution of 1 mum. A polysilicon thin-film twisted nematic SVGA SLM is used as the dynamic photolithographic mask. The system consists of eight elements: a UV laser light source, an optical shutter, beam-conditioning optics, a SLM, a multielement reduction lens system, a high-resolution translation stage, a control system, and a computer-aided-design system. Each of these system components is briefly described. In addition, the optical characteristics of commercially available UV curable resins are investigated with nondegenerate four-wave mixing. Holographic gratings were written at a wavelength of 351.1 nm and read at 632.8 nm to compare the reactivity, curing speed, shrinkage, and resolution of the resins. These experiments were carried out to prove the suitability of these photopolymerization systems for microstereolithography.     

Symbiotic coevolutionary genetic programming: a benchmarking study under large attribute spaces

Classification under large attribute spaces represents a dual learning problem in which attribute subspaces need to be identified at the same time as the classifier design is established. Embedded as opposed to filter or wrapper methodologies address both tasks simultaneously. The motivation for this work stems from the observation that team based approaches to Genetic Programming (GP) have the potential to design multiple classifiers per class—each with a potentially unique attribute subspace—without recourse to filter or wrapper style preprocessing steps. Specifically, competitive coevolution provides the basis for scaling the algorithm to data sets with large instance counts; whereas cooperative coevolution provides a framework for problem decomposition under a bid-based model for establishing program context. Symbiosis is used to separate the tasks of team/ensemble composition from the design of specific team members. Team composition is specified in terms of a combinatorial search performed by a Genetic Algorithm (GA); whereas the properties of individual team members and therefore subspace identification is established under an independent GP population. Teaming implies that the members of the resulting ensemble of classifiers should have explicitly non-overlapping behaviour. Performance evaluation is conducted over data sets taken from the UCI repository with 649–102,660 attributes and 2–10 classes. The resulting teams identify attribute spaces 1–4 orders of magnitude smaller than under the original data set. Moreover, team members generally consist of less than 10 instructions; thus, small attribute subspaces are not being traded for opaque models.     

Towards a universal disulphide stabilised single chain Fv format: importance of interchain disulphide bond location and vL-vH orientation

Engineered introduction of interface interchain disulphide bonds is perceived to be a simple method to increase the stability of single chain Fv (scFv). Six disulphide bond locations have been cited within the literature but the potential for the broad use of each has not been examined. Five of these disulphide bond locations were introduced into one scFv in order to compare their relative effects on expression, thermal stability, percent monomer formation and retention of antigen binding. The disulphide bond position vH44-vL100 was observed to enable the most favourable balance of biophysical properties. The vH44-vL100 disulphide bond was introduced into five additional scFv in both vL-vH and vH-vL orientations in order to investigate its general applicability. Data are presented to show the relative influence of scFv sequence, v-region organisation and interchain disulphide bond on expression yield, thermal stability and percent monomer. Introduction of the vH44-vL100 disulphide bond typically resulted in no or little increase in thermal stability and no change in percent monomer but did confer the benefit of permanently fixing monomer:dimer ratios during purification and analysis.