How Elastic is The Demand for Labor?

This paper investigates the magnitude of the elasticity of demand for labor in time series data using more general and complete models of demand than have been previously employed. It argues that previous analyses have imposed two invalid constraints in calculations, which bias downward estimated elasticities. The first invalid constraint is the assumption that real capital prices have an equal opposite effect to real wages in the demand equation. We show on measurement error grounds that this constraint should not be imposed in econometric work even when long run homogeneity of prices correctly characterizes the market. The constraint is rejected in the data. The second invalid constraint is that all explanatory variables have the same lag distribution. We argue that this constraint is invalid when decisions are made under uncertainty and find that it is also rejected by the data. The principal positive empirical finding is that with the constraints relaxed, the elasticity, of demand with respect to real wages is much larger than the estimates in the literature, indicating much greater price responsiveness on the demand side of the labor market than has previously been thought.

The effect of blocking selected endocytic mechanisms on heterologous protein secretion in the yeast saccharomyces cerevisiae

>Magister Scientiae - MScThe yeast Saccharomyces cerevisiae is considered a good host used for heterologous protein production due to the organism’s microbial safety, rapid growth and eukaryotic post- translational processing. As a fermentative organism, S. cerevisiae is thus not only a useful platform for the production of biopharmaceuticals and industrial enzymes, but also a promising organism for second-generation biofuel production. Substantial effort has been focused on alleviating the many bottlenecks in recombinant gene expression, as well as in the secretory pathway to enhance heterologous protein titres. It was recently shown that highly active endocytosis could decrease the overall secreted protein titre in the supernatant. In this study, we aimed to block endocytotic and vacuolar complexes to ultimately disrupt, or impair, the endocytotic and vacuolar mechanisms of proteolysis and test the effect that this would have on secreted heterologous protein titres. This was accomplished by knocking out various genes involved in endocytosis and transforming the strains with genes encoding various hydrolases including β-glucosidase (Bgl), xylanase (Xyn2), endoglucanase (Eg2) and cellobiohydrylase (Cbh1). Our study demonstrated that genetic blocking of endocytotic mechanisms as well as vacuolar complexes could theoretically improve heterologous protein secretion in S. cerevisiae. Endoglucanase (Eg2) titres displayed improvement of 26% and 30% in strains which had the RVS161 and VRP1 genes deleted and xylanase titres displayed an improvement of 71% and 143% in strains with the END3 and SSA4 gene deletions. Several of the gene knockouts tested improved Xyn2 and Eg2 titres but the effect of the different gene targets varied widely. A double knock-out strain with deletions in CLC1 and RVS161 secreted 104% more Eg2 than its parental control strain on a per dry cell weight basis, a significant synergistic improvement. Other double knock-out strains displayed additive or similar activities when compared to their controls. Cbh1 secretion could not be improved through the gene deletions tested in our study and Bgl activity could not be measured in our transformants. These results demonstrate the different relationships of various heterologous proteins with various components of the secretion machinery and may also imply how endocytosis as well as vacuolar complexes affect the level of secreted protein

Colorectal Cancer Brochure Development for African Americans

Introduction: African Americans are more likely to die from colorectal cancer (CRC) than any other racial/ethnic group in the United States. Unfortunately, African Americans are also less likely to undergo screening for CRC than their White counterparts. Focus groups methodology was used to refine educational brochures designed to increase CRC screening among African Americans. Methods: Two series of focus groups were completed, with a total of seven groups and 39 participants. Six different brochures (stage-matched and culturally sensitive) designed to promote CRC screening among African Americans were evaluated. Results: All participants thought that the brochures motivated them to talk with their health care providers about screening. Cost, pain, medical mistrust and fear were identified as major barriers and the brochures were modified to address these concerns. Conclusions: Focus groups methodology with African Americans can be used to inform brochures designed to increase African Americans CRC screening that addresses their major concerns

First-principles investigation of magnetism and electronic structures of substitutional 3d3d transition-metal impurities in bcc Fe

The magnetic and electronic structures of $3d$ impurity atoms from Sc to Zn in ferromagnetic body-centered cubic iron are investigated using the all-electron full-potential linearized augmented plane-wave method based on the generalized gradient approximation (GGA). We found that in general, the GGA results are closer to the experimental values than those of the local spin density approximation. The calculated formation enthalpy data indicate the importance of a systematic study on the ternary Fe-C-$X$ systems rather than the binary Fe-$X$ systems, in steel design. The lattice parameters are optimized and the conditions for spin polarization at the impurity sites are discussed in terms of the local Stoner model. Our calculations, which are consistent with previous work, imply that the local spin-polarizations at Sc, Ti, V, Cu, and Zn are induced by the host Fe atoms. The early transition-metal atoms couple antiferromagnetically, while the late transition-metal atoms couple ferromagnetically, to the host Fe atoms. The calculated total magnetization ($M$) of bcc Fe is reduced by impurity elements from Sc to Cr as a result of the antiferromagnetic interaction, with the opposite effect for solutes which couple ferromagnetically. The changes in $M$ are attributed to nearest neighbor interactions, mostly between the impurity and host atoms. The atom averaged magnetic moment is shown to follow generally the well-known Slater-Pauling curve, but our results do not follow the linearity of the Slater-Pauling curve. We attribute this discrepancy to the weak ferromagnetic nature of bcc Fe. The calculated Fermi contact hyperfine fields follow the trend of the local magnetic moments. The effect of spin-orbit coupling is found not to be significant although it comes into prominence at locations far from the impurity sites.Comment: 26 pages, 11 figure

Commonwealth Singers

Disc Two of Two VCU Women\u27s Choir and VCU Commonwealth Singers present Open Minds: Music that Mend

The Horizon: A blended wing aircraft configuration design project, volume 3

The results of a study to design a High-Speed Civilian Transport (HSCT) using the blended wing-body configuration are presented. The HSCT is a Mach 2 to 5 transport aircraft designed to compete with current commercial aircraft. The subjects discussed are sizing, configuration, aerodynamics, stability and control, propulsion, performance, structures and pollution effects