Spatial distribution of transcript changes in the maize primary root elongation zone at low water potential

Background: Previous work showed that the maize primary root adapts to low Ψw (-1.6 MPa) by maintaining longitudinal expansion in the apical 3 mm (region 1), whereas in the adjacent 4 mm (region 2) longitudinal expansion reaches a maximum in well-watered roots but is progressively inhibited at low Ψw. To identify mechanisms that determine these responses to low Ψw, transcript expression was profiled in these regions of water-stressed and well-watered roots. In addition, comparison between region 2 of water-stressed roots and the zone of growth deceleration in well-watered roots (region 3) distinguished stress-responsive genes in region 2 from those involved in cell maturation. Results: Responses of gene expression to water stress in regions 1 and 2 were largely distinct. The largest functional categories of differentially expressed transcripts were reactive oxygen species and carbon metabolism in region 1, and membrane transport in region 2. Transcripts controlling sucrose hydrolysis distinguished well-watered and water-stressed states (invertase vs. sucrose synthase), and changes in expression of transcripts for starch synthesis indicated further alteration in carbon metabolism under water deficit. A role for inositols in the stress response was suggested, as was control of proline metabolism. Increased expression of transcripts for wall-loosening proteins in region 1, and for elements of ABA and ethylene signaling were also indicated in the response to water deficit. Conclusion: The analysis indicates that fundamentally different signaling and metabolic response mechanisms are involved in the response to water stress in different regions of the maize primary root elongation zone

Methylation of WTH3, a possible drug resistant gene, inhibits p53 regulated expression

<p>Abstract</p> <p>Background</p> <p>Previous results showed that over-expression of the <it>WTH3 </it>gene in MDR cells reduced <it>MDR1 </it>gene expression and converted their resistance to sensitivity to various anticancer drugs. In addition, the <it>WTH3 </it>gene promoter was hypermethylated in the MCF7/AdrR cell line and primary drug resistant breast cancer epithelial cells. <it>WTH3 </it>was also found to be directly targeted and up regulated by the <it>p53 </it>gene. Furthermore, over expression of the <it>WTH3 </it>gene promoted the apoptotic phenotype in various host cells.</p> <p>Methods</p> <p>To further confirm <it>WTH3</it>'s drug resistant related characteristics, we recently employed the small hairpin RNA (shRNA) strategy to knockdown its expression in HEK293 cells. In addition, since the <it>WTH3 </it>promoter's p53-binding site was located in a CpG island that was targeted by methylation, we were interested in testing the possible effect this epigenetic modification had on the <it>p53 </it>transcription factor relative to <it>WTH3 </it>expression. To do so, the <it>in vitro </it>methylation method was utilized to examine the <it>p53 </it>transgene's influence on either the methylated or non-methylated <it>WTH3 </it>promoter.</p> <p>Results</p> <p>The results generated from the gene knockdown strategy showed that reduction of <it>WTH3 </it>expression increased <it>MDR1 </it>expression and elevated resistance to Doxorubicin as compared to the original control cells. Data produced from the methylation studies demonstrated that DNA methylation adversely affected the positive impact of <it>p53 </it>on <it>WTH3 </it>promoter activity.</p> <p>Conclusion</p> <p>Taken together, our studies provided further evidence that <it>WTH3 </it>played an important role in MDR development and revealed one of its transcription regulatory mechanisms, DNA methylation, which antagonized <it>p53</it>'s positive impact on <it>WTH3 </it>expression.</p

Forecasting the Direction of Short-Term Crude Oil Price Changes with Genetic-Fuzzy Information Distribution

This paper proposes a novel approach to the directional forecasting problem of short-term oil price changes. In this approach, the short-term oil price series is associated with incomplete fuzzy information, and a new fused genetic-fuzzy information distribution method is developed to process such a fuzzy incomplete information set; then a feasible coding method of multidimensional information controlling points is adopted to fit genetic-fuzzy information distribution to time series forecasting. Using the crude oil spot prices of West Texas Intermediate (WTI) and Brent as sample data, the empirical analysis results demonstrate that the novel fused genetic-fuzzy information distribution method statistically outperforms the benchmark of logistic regression model in prediction accuracy. The results indicate that this new approach is effective in direction accuracy

Price strategies and salesforce compensation design with overconfident sales agent

Salesforce compensation and pricing decisions have invoked the interest of several academicians and practitioners for a long period of time. However, dilemma of whether the pricing decisions should be made by the firm or delegated to the sales agent, especially the overconfident agent, is still unexplored. This study tries to investigate the problems associated with this dilemma by conducting a thorough study of the scenario, it studies a supply chain that the rational manufacturer hiring an overconfident sales agent to sell its products, the agent might overestimate the demand, or underestimate the variability of the demand. These behaviors are characterized as ability-based and precision-based overconfidence respectively. The models are designed for centralized pricing and delegated pricing settings, and the sensitivity analysis are conducted. Moreover, comparative studies have also been conducted to highlight the impacts of the two types of overconfidence on the compensation decisions under different pricing strategies. It was found out that, the manufacturer favors centralized pricing, while the sales agent prefers delegated pricing. The final decisions of both sides deviate considerably from the rational scenario, overconfidence prompts the agent to exert more efforts, which ultimately enhances manufacturer’s profits that the manufacturer should hire a more overconfident agent, while not guaranteeing a higher commission rate. Overconfidence leads to the decline of the agent’s actual utility, and the loss amount increases with the overconfidence level. The influences of the both types of overconfidence are substitutable. Managerial insights are also provided for various scenarios and propositions along with numerical illustration of the finding

Monitoring strategies of enterprise’s emission reduction with asymmetric information

More recently, the Chinese Government had been making appreciable efforts to stimulate and encourage entrepreneurial emission reductions. These efforts could be boosted by availability of dual asymmetric information about the adopted technology for efficient reduction and enterprises’ investment strategies, possibly leading to adverse selection and moral hazard. This paper incorporates Stackelberg game model and incentive mechanism theory to find a feasible solution to dual asymmetric information problem. Hence firstly, through application of linear function of the total emission, an emission reduction contract would be formulated for regulating incentive payments from government to supervisory authorities followed by derivation of a two stage principal-agent monitoring model based on the enterprise’s private information and action respectively. Some findings have been obtained through analysis of the monitoring models along with their comparison with the results of no monitoring scenario which confirm the effectiveness of hiring the supervisory authorities for monitoring of enterprises’ emission reduction, which, ultimately, would facilitate increasing payoff and efficient emission reduction. In this perspective, the action-based monitoring mechanism depicts overall government dominance. Several, managerial insights have also been provided for various scenarios and propositions and all the findings are illustrated numerically. It could prove highly beneficial and significant to the government in encouraging entrepreneurial emission reductions

Hydrodeoxygenation of Lignin-Derived Phenolic Monomers and Dimers to Alkane Fuels over Bifunctional Zeolite-Supported Metal Catalysts

A bifunctional catalyst of Ru supported in zeolite HZSM-5, Ru/HZSM-5 (Si/Al = 25), exhibited excellent hydrodeoxygenation activity toward the conversion of lignin-derived phenolic monomers and dimers to cycloalkanes in aqueous solution. The oxygen-containing groups in mono- and binuclear phenols were removed through a cleavage of C-O bonds in phenolics followed by an integrated metal- and acid-catalyzed hydrogenation and dehydration. As a bifunctional catalyst Ru/HZSM-5, the presence of both the Bronsted acid site in the pores of HZSM-5 for dehydration and a metallic function of Ru for hydrogenation was indispensible for the formation of alkanes from lignin-derived phenolics. Our findings also reveal that the Ru/HZSM-5 with the lowest Si/Al ratio of HZSM-5 proved to be most selective to cycloalkanes, indicating that more acid sites over zeolite are favorable for the dehydration of cyclohexanol during hydrodeoxygenation process, which leads higher selectivity to hydrocarbons. This approach for the construction of bifunctional catalyst highlights an efficient route for hydrodeoxygenation of lignin-derived phenolic oil to transportation biofuels

Conversion of fructose into 5-hydroxymethylfurfural catalyzed by recyclable sulfonic acid-functionalized metal-organic frameworks

A series of sulfonic acid-functionalized metal-organic frameworks (MOF-SO3H) were prepared by postsynthetic modification (PSM) of the organic linkers within the MOF with chlorosulfonic acid. The obtained MOF-SO3H, including sulfonic acid-functionalized MIL-101(Cr) [MIL-101(Cr)-SO3H], UIO-66(Zr) [UIO-66(Zr)-SO3H], and MIL-53(Al) [MIL-53(Al)-SO3H], have been systematically studied as solid acids in fructose transformation to 5-hydroxymethylfurfural (HMF). With MIL-101(Cr)-SO3H as catalyst, a HMF yield of 90% with a full fructose conversion was obtained at 120 degrees C for 60 min in DMSO. The concentration of -SO3H in MOF-SO3H as well as the contribution of Bronsted acidity of MOF-SO3H parallels its -SO3H grafting rate. Under a lower -SO3H grafting level, a good linear correlation between catalytic activity, in terms of turnover frequency, and sulfonic acid-site density of MOF-SO3H was found. Moreover, the sulfonic acid groups, which function as the catalytic sites, are equivalent in all MOF-SO3H for fructose-to-HMF transformation, regardless of precursor MOFs. Both conversions of fructose and selectivities towards HMF increase with the sulfonic acid-site density of MOF-SO3H at an initial stage of fructose-to-HMF transformation. Kinetics studies reveal that the MIL-101(Cr)-SO3H promoted fructose-to-HMF transformation may follow pseudo-first-order kinetics with observed activation energy of 55 kJ mol(-1) under the investigated conditions. Moreover, MIL-101(Cr)-SO3H behaves as a heterogeneous catalyst and can be easily recovered and reused. The research highlights a good prospect for catalytic application of MOF-derived solid acid catalysts for biomass carbohydrate valorization

Hydrodeoxygenation of Lignin-Derived Phenolic Monomers and Dimers to Alkane Fuels over Bifunctional Zeolite-Supported Metal Catalysts

A bifunctional catalyst of Ru supported in zeolite HZSM-5, Ru/HZSM-5 (Si/Al = 25), exhibited excellent hydrodeoxygenation activity toward the conversion of lignin-derived phenolic monomers and dimers to cycloalkanes in aqueous solution. The oxygen-containing groups in mono- and binuclear phenols were removed through a cleavage of C–O bonds in phenolics followed by an integrated metal- and acid-catalyzed hydrogenation and dehydration. As a bifunctional catalyst Ru/HZSM-5, the presence of both the Brønsted acid site in the pores of HZSM-5 for dehydration and a metallic function of Ru for hydrogenation was indispensible for the formation of alkanes from lignin-derived phenolics. Our findings also reveal that the Ru/HZSM-5 with the lowest Si/Al ratio of HZSM-5 proved to be most selective to cycloalkanes, indicating that more acid sites over zeolite are favorable for the dehydration of cyclohexanol during hydrodeoxygenation process, which leads higher selectivity to hydrocarbons. This approach for the construction of bifunctional catalyst highlights an efficient route for hydrodeoxygenation of lignin-derived phenolic oil to transportation biofuels