57 research outputs found

    S 4

    Full text link
    Numerical solution of the transport equation for monoenergetic neutrons scattered isotropically through the medium of a finite homogeneous slab is studied for the determination of the eigenvalues. After obtaining the discrete ordinates form of the transport equation, separated homogeneous and particular solutions are formed and then the eigenvalues are calculated using the Gauss-Legendre quadrature set. Then, the calculated eigenvalues for various values of the c0, the mean number of secondary neutrons per collision, are given in the tables

    How to Educate Entrepreneurs?

    Get PDF
    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

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>We have previously found that TLR4-deficient (TLR4-/-) mice demonstrate decreased expression of mucosal PGE <sub>2 </sub>and are protected against colitis-associated neoplasia. However, it is still unclear whether PGE <sub>2 </sub>is 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 <sub>2 </sub>in TLR4-/- mice to see if PGE <sub>2 </sub>bypasses 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 <sub>2 </sub>(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 <sub>2 </sub>during 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 <sub>2 </sub>treatment 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 <sub>2 </sub>treatment. Endogenous prostanoid synthesis was differentially affected by PGE <sub>2 </sub>treatment during acute and recovery phases of colitis. Exogenous administration of PGE <sub>2 </sub>increased colitis-associated tumorigenesis but this only occurred during the recovery phase. Lastly, PGE <sub>2 </sub>treatment 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 <sub>2 </sub>as a central downstream molecule involving TLR4-mediated intestinal tumorigenesis.</p

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

    No full text
    WOS: 000245230000010The U-N 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
    corecore