How to Educate Entrepreneurs?

Entrepreneurship education has two purposes: To improve students’ entrepreneurial skills and to provide impetus to those suited to entrepreneurship while discouraging the rest. While entrepreneurship education helps students to make a vocational decision its effects may conflict for those not suited to entrepreneurship. This study shows that vocational and the skill formation effects of entrepreneurship education can be identified empirically by drawing on the Theory of Planned Behavior. This is embedded in a structural equation model which we estimate and test using a robust 2SLS estimator. We find that the attitudinal factors posited by the Theory of Planned Behavior are positively correlated with students’ entrepreneurial intentions. While conflicting effects of vocational and skill directed course content are observed in some individuals, overall these types of content are complements. This finding contradicts previous results in the literature. We reconcile the conflicting findings and discuss implications for the design of entrepreneurship courses

The role of prostaglandin E2 (PGE 2) in toll-like receptor 4 (TLR4)-mediated colitis-associated neoplasia

<p>Abstract</p> <p>Background</p> <p>We have previously found that TLR4-deficient (TLR4-/-) mice demonstrate decreased expression of mucosal PGE ₂and are protected against colitis-associated neoplasia. However, it is still unclear whether PGE ₂is the central factor downstream of TLR4 signaling that promotes intestinal tumorigenesis. To further elucidate critical downstream pathways involving TLR4-mediated intestinal tumorigenesis, we examined the effects of exogenously administered PGE ₂in TLR4-/- mice to see if PGE ₂bypasses the protection from colitis-associated tumorigenesis.</p> <p>Method</p> <p>Mouse colitis-associated neoplasia was induced by azoxymethane (AOM) injection followed by two cycles of dextran sodium sulfate (DSS) treatment. Two different doses of PGE ₂(high dose group, 200 μg, n = 8; and low dose group, 100 μg, n = 6) were administered daily during recovery period of colitis by gavage feeding. Another group was given PGE ₂during DSS treatment (200 μg, n = 5). Inflammation and dysplasia were assessed histologically. Mucosal Cox-2 and amphiregulin (AR) expression, prostanoid synthesis, and EGFR activation were analyzed.</p> <p>Results</p> <p>In control mice treated with PBS, the average number of tumors was greater in WT mice (n = 13) than in TLR4-/- mice (n = 7). High dose but not low dose PGE ₂treatment caused an increase in epithelial proliferation. 28.6% of PBS-treated TLR4-/- mice developed dysplasia (tumors/animal: 0.4 ± 0.2). By contrast, 75.0% (tumors/animal: 1.5 ± 1.2, P < 0.05) of the high dose group and 33.3% (tumors/animal: 0.3 ± 0.5) of the low dose group developed dysplasia in TLR4-/- mice. Tumor size was also increased by high dose PGE ₂treatment. Endogenous prostanoid synthesis was differentially affected by PGE ₂treatment during acute and recovery phases of colitis. Exogenous administration of PGE ₂increased colitis-associated tumorigenesis but this only occurred during the recovery phase. Lastly, PGE ₂treatment increased mucosal expression of AR and Cox-2, thus inducing EGFR activation and forming a positive feedback mechanism to amplify mucosal Cox-2.</p> <p>Conclusions</p> <p>These results highlight the importance of PGE ₂as a central downstream molecule involving TLR4-mediated intestinal tumorigenesis.</p

Review of solar energetic particle models

Solar Energetic Particle (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to improve the scientific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data.</p

A spectral nodal method for one-group X,Y,Z-cartesian geometry discrete ordinates problems

The solution of one-group discrete ordinates SN problems with linearly anisotropic scattering in x,y,z - cartesian geometry has been studied by using SGF-CN " spectral Green's function-constant nodal " method, developed first by De Barrros and Larsen (1990-1992) for one dimensional and two dimensional x,y - cartesian geometries. The solutions of SN transverse - integrated nodal equations in which only constant nodal volume leakage approximation is made, are obtained by a simple iterative algorithm. Finally, tabulated numerical results of average cell scalar fluxes are provided

Eigenvalue spectrum with chebyshev polynomial approximation of the transport equation in slab geometry

Using certain well-known properties of chebyshev polynomials, a simple and highly efficient approach to evaluate eigenvalue in radiation transport is presented. The spectrum of eigenvalues has been studied for slabs with isotropic scattering of different magnitudes of the cross section parameter c (i.e., the mean number of neutrons emitted per collision). It is shown that in the presence of the chebyshev polynomial approximation (TN) there are both discrete and continuum of eigenvalues. It is found that the TN method gives very good agreement with conventional spherical harmonics approximation (PN). © 2005 Elsevier Ltd. All rights reserved

TN method for the critical thickness of one-speed neutrons in a slab with forward and backward scattering

The critical slab problem in the case of combination of forward and backward scattering with usual isotropic scattering is studied for one-speed neutrons in a uniform finite slab by using TN method based on Chebyshev polynomial approximation and Marshak boundary conditions. It is shown that TN method gives accurate results in one-dimensional geometry and is very efficient both in derivation of equations and rapid convergence. Numerical results obtained by TN method are compared against the PN method in tabular form, which agreed quite well. © 2006 Elsevier Ltd. All rights reserved

Application of the UN method to the reflected critical slab problem for one-speed neutrons with forward and backward scattering

The UN method is used to solve the critical slab problem for reflecting boundary conditions in one-speed neutron transport theory. The isotropic scattering kernel with the combination of forward and backward scattering is chosen for the neutrons in a uniform finite slab. It is shown that the method converges rapidly with easily executable equations. The presented numerical results are compared with the results available in the literature. © Carl Hanser Verlag

T-N approximation to reflected slab and computation of the critical half thicknesses

WOS: 000238203000011The criticality solution to one-speed neutron transport equation using the T-N approximation is described for reflected slab. In the solution, Marshak type boundary condition is used. The critical half thicknesses are computed for different values of c and reflection coefficients. Computations are made by using the both T-N and P-N approximation for the comparison. (C) 2005 Elsevier Ltd. All rights reserved

Spectral green's function method for neutron transport with backward and forward scattering in 1-D slab and spherical geometry

In this work, a combination of forward and backward scattering is studied for the numerical solution of one-dimensional neutron transport problems in a finite homogeneous slab and sphere. The scattering of the neutrons is assumed to be anisotropic for the slab and isotropic for the spherical geometry. Numerical solutions are carried out by using both the spectral Green's function (SGF) and the diamond-difference (DD) methods to check the accuracy of the results. Calculated numerical results of cell-edge scalar fluxes are presented in the tables

Application of the spectral Green's function method for numerically solving discrete ordinates problems in cylindrical geometry

The spectral Green's function (SGF) method is used to solve numerically the transport of neutrons in an infinite homogeneous cylindrical domain. In the method, the scattering of neutrons is assumed to be isotropic and the transport equation in cylindrical geometry is reduced to plane-like transport equation by using our reasonable approach. Then, the plane-like transport equation is solved by using the SGF method and the results are compared with those already obtained by the Diamond Difference (DD) scheme to check the accuracy of the results. The agreement of the results is good and it can be concluded that the SGF method is very effective for the numerical solution of the transport equation. © Carl Hanser Verlag