Solution Electrospinning of Polyolefins: The Effect of Comonomers in Propylene/α‐Olefin Copolymers

Two propylene copolymers with similar comonomer content and molecular weight were electrospun from solution. The 1‐octene and 1‐decene copolymers yielded ribbon‐like fibers. Isotactic poly(propylene) prepared by both heterogeneous and homogeneous catalyst systems could not be electrospun from the same solvent system used for the copolymers. The presence of the higher 1‐alkene comonomers in small amounts (about 1 mol‐%) not only affects the crystallinity of the polymer compared to the homopolymer, but appears to influence the solubility as well. The combined effect of lowering crystallinity and increasing solubility indicates that the use of higher 1‐alkene comonomers in low amounts could be a route to prepare poly(propylene) based electrospun fibers.

     

Nutrient content of South African C2 beef offal

The aim of this study was to determine a selected group of nutrients in raw and cooked C-age, fat code 2, bovine offal and to evaluate it as a potential source of nutrients such as protein and iron. Samples of the different raw and cooked C-age, fat code 2 bovine offal parts were analysed by accredited laboratories. Cooking affected mainly the nutrients such as moisture, protein, fat, ash and energy as well as the micronutrient values, which were higher in the cooked offal cuts. Some cuts of offal (heart, lungs and spleen) are as lean as or leaner than chicken meat. The biggest difference could be attributed to the difference in fat content between the cuts, for example, the tongue is very high in fat with 23.30 g/100 g and therefore has the highest kJ (1,157 kJ) content of the six cuts of offal. The spleen had the highest iron content of 36.6 mg/100 g. Significantly lower fat contents were observed in the lungs (2.53 g/100 g), heart (6.7 g/100 g) and the spleen (3.20 g/100 g) cuts when compare to the values in the 1999 version of the South African Medical Research Council’s Food Composition Tables. The heart, intestine and spleen are also an important source of iron and compare favourable to beef. The heart also contained the highest zinc content of all the cuts. Offal containing primary food components which have high potential in human nutrition such as high protein content and can therefore is recommended as a good low cost nutritious product.     

Behavioral profile of a heterozygous mutant mouse model for EGF-like domain neuregulin 1.

Human genetic studies have demonstrated that the neuregulin 1 gene (NRG1) is involved in the development of schizophrenia. Alternative splicing of NRG1 results in at least 15 distinct isoforms and all contain an extracellular epidermal growth factor (EGF)-like domain, which is sufficient for Nrg1's biological activity. Here, we characterize a heterozygous mutant model for mouse EGF-like domain neuregulin 1 (Nrg1) regarding schizophrenia-related behavioral domains. A comprehensive, multitiered phenotyping strategy was used to investigate locomotion, exploration, anxiety-related behaviors, and sensorimotor gating. Nrg1 mutant mice exhibited a hyper-locomotive phenotype and an improved ability to habituate to a new environment. Extensive analysis of anxiety-related behaviors revealed a wild type-like phenotype in this domain. However, a moderate impairment in sensorimotor gating was found after pharmacological challenge using psychoactive substances. Our study adds to the increasing behavioral data available from a variety of animal models for Nrg1 isoforms. We suggest a standardized and comprehensive behavioral phenotyping approach to distinguish between the different models and to clarify their relevance for schizophrenia research. Future behavioral investigations will focus on the negative and cognitive symptoms of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of efficient sampling designs for urban stormwater monitoring

Monitoring programs for urban runoff have not been assessed for effectiveness or efficiency in estimating mass emissions. In order to determine appropriate designs for stormwater, total suspended solids (TSS) and flow information from the Santa Ana River was collected nearly every 15 min for every storm of the 1998 water year. All samples were used to calculate the "true load" and then three within-storm sampling designs (flow-interval, time-interval, and simple random) and five among-storm sampling designs (stratified by size, stratified by season, simple random, simple random of medium and large storms, and the first m storms of the season) were simulated. Using these designs, we evaluated three estimators for storm mass emissions (mean, volume-weighted, and ratio) and three estimators for annual mass emissions (median, ratio, and regular). Designs and estimators were evaluated with respect to accuracy and precision. The optimal strategy was used to determine the appropriate number of storms to sample annually based upon confidence interval width for estimates of annual mass emissions and concentration. The amount of detectable trend in mass emissions and concentration was determined for sample sizes 3 and 7. Single storms were most efficiently characterized (small bias and standard error) by taking 12 samples following a flow-interval schedule and using a volume-weighted estimator of mass emissions. The ratio estimator, when coupled with the simple random sample of medium and large storms within a season, most accurately estimated concentration and mass emissions; and had low bias over all of the designs. Sampling seven storms is the most efficient method for attaining small confidence interval width for annual concentration. Sampling three storms per year allows a 20% trend to be detected in mass emissions or concentration over five years. These results are decreased by 10% by sampling seven storms per year.