Evolution of twist-3 fragmentation functions in multicolour QCD and the Gribov-Lipatov reciprocity

It is shown that twist-3 fragmentation functions in the large-$N_c$ limit of QCD obey the DGLAP evolution equations. The anomalous dimensions are found explicitly. The Gribov-Lipatov reciprocity is violated at the twist-3 level in the leading logarithmic approximation.Comment: 7 pages, Late

Overlimiting Current and Shock Electrodialysis in Porous Media

Most electrochemical processes, such as electrodialysis, are limited by diffusion, but in porous media, surface conduction and electro-osmotic flow also contribute to ionic fluxes. In this paper, we report experimental evidence for surface-driven over-limiting current (faster than diffusion) and deionization shocks (propagating salt removal) in a porous medium. The apparatus consists of a silica glass frit (1 mm thick with 500 nm mean pore size) in an aqueous electrolyte (CuSO$_4$ or AgNO$_3$) passing ionic current from a reservoir to a cation-selective membrane (Nafion). The current-voltage relation of the whole system is consistent with a proposed theory based on the electro-osmotic flow mechanism over a broad range of reservoir salt concentrations (0.1 mM - 1.0 M), after accounting for (Cu) electrode polarization and pH-regulated silica charge. Above the limiting current, deionized water ($\approx 10 \mu$ $M$) can be continuously extracted from the frit, which implies the existence of a stable shock propagating against the flow, bordering a depleted region that extends more than 0.5mm across the outlet. The results suggest the feasibility of "shock electrodialysis" as a new approach to water desalination and other electrochemical separations.Comment: 39 pages, 9 fig

BEX2 has a functional interplay with c-Jun/JNK and p65/RelA in breast cancer.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: We have previously demonstrated that BEX2 is differentially expressed in breast tumors and has a significant role in promoting cell survival and growth in breast cancer cells. BEX2 expression protects breast cancer cells against mitochondrial apoptosis and G1 cell cycle arrest. In this study we investigated the transcriptional regulation of BEX2 and feedback mechanisms mediating the cellular function of this gene in breast cancer. RESULTS: We found a marked induction of BEX2 promoter by c-Jun and p65/RelA using luciferase reporter assays in MCF-7 cells. Furthermore, we confirmed the binding of c-Jun and p65/RelA to the BEX2 promoter using a chromatin immunoprecipitation assay. Importantly, transfections of c-Jun or p65/RelA in MCF-7 cells markedly increased the expression of BEX2 protein. Overall, these results demonstrate that BEX2 is a target gene for c-Jun and p65/RelA in breast cancer. These findings were further supported by the presence of a strong correlation between BEX2 and c-Jun expression levels in primary breast tumors. Next we demonstrated that BEX2 has a feedback mechanism with c-Jun and p65/RelA in breast cancer. In this process BEX2 expression is required for the normal phosphorylation of p65 and IkappaB alpha, and the activation of p65. Moreover, it is necessary for the phosphorylation of c-Jun and JNK kinase activity in breast cancer cells. Furthermore, using c-Jun stable lines we showed that BEX2 expression is required for c-Jun mediated induction of cyclin D1 and cell proliferation. Importantly, BEX2 down-regulation resulted in a significant increase in PP2A activity in c-Jun stable lines providing a possible underlying mechanism for the regulatory effects of BEX2 on c-Jun and JNK. CONCLUSIONS: This study shows that BEX2 has a functional interplay with c-Jun and p65/RelA in breast cancer. In this process BEX2 is a target gene for c-Jun and p65/RelA and in turn regulates the phosphorylation/activity of these proteins. These suggest that BEX2 is involved in a novel feedback mechanism with significant implications for the biology of breast cancer

Comparison of mechanical properties of wheat and rice straw influenced by loading rates

This study investigates the comparison of mechanical properties of wheat and rice straw such as shear strength, specific shearing energy and cutting forces. The experiments were conducted at three loading rate of 15, 20 and 25 mm min-1 and three internode positions 70 (N1), 130 (N2) and 190 (N3) mm down from the ear. Results show that by increasing the loading rate, strength of wheat and rice straw changed from 8.12 to 22.94 and 6.06 to 14.33 MPa and specific shear energy was varied from 12.10 to 18.64 and 10.40 to 16.17 mJ mm-2, respectively. Moreover, the values of cutting forces of wheat and rice straw were within the ranges 13.23 to 19.50 and 9.40 to 16.70 N. Whereas the shear strength, specific shearing energy and cutting force were higher at higher loading rate at the third internode of both straw internode positions. The shear strength, specific shearing energy and cutting force of rice straw were significantly higher (p<0.05) than that of wheat straw. With respect to the findings of the present research study, it is concluded that with decreasing loading rate of cutting blade toward the first internode, more energy can be saved by harvesting and threshing machines.Keywords: Cutting force, rice straw, shear strength, specific shearing energy, wheat strawAfrican Journal of Biotechnology Vol. 12(10), pp. 1068-107