A genetic locus and gene expression patterns associated with the priming effect on lettuce seed germination at elevated temperatures

Seeds of most cultivated varieties of lettuce (Lactuca sativa L.) fail to germinate at warm temperatures (i.e., above 25–30°C). Seed priming (controlled hydration followed by drying) alleviates this thermoinhibition by increasing the maximum germination temperature. We conducted a quantitative trait locus (QTL) analysis of seed germination responses to priming using a recombinant inbred line (RIL) population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. Priming significantly increased the maximum germination temperature of the RIL population, and a single major QTL was responsible for 47% of the phenotypic variation due to priming. This QTL collocated with Htg6.1, a major QTL from UC96US23 associated with high temperature germination capacity. Seeds of three near-isogenic lines (NILs) carrying an Htg6.1 introgression from UC96US23 in a Salinas genetic background exhibited synergistic increases in maximum germination temperature in response to priming. LsNCED4, a gene encoding a key enzyme (9-cis-epoxycarotinoid dioxygenase) in the abscisic acid biosynthetic pathway, maps precisely with Htg6.1. Expression of LsNCED4 after imbibition for 24 h at high temperature was greater in non-primed seeds of Salinas, of a second cultivar (Titan) and of NILs containing Htg6.1 compared to primed seeds of the same genotypes. In contrast, expression of genes encoding regulated enzymes in the gibberellin and ethylene biosynthetic pathways (LsGA3ox1 and LsACS1, respectively) was enhanced by priming and suppressed by imbibition at elevated temperatures. Developmental and temperature regulation of hormonal biosynthetic pathways is associated with seed priming effects on germination temperature sensitivity

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

Do women directors contribute to R&D? The role of critical mass and expert power

The paper provides insights into the implications for innovation input of having women on company boards. It sheds light on the effects of critical mass and expert power of women directors, and the moderating role played by female CEOs. Drawing on a sample of Italian companies in the high-tech industry, the study shows that having women on the board positively affects innovation input, measured as R&D spending, but only when they reach a critical mass. This result highlights that having a critical mass of women directors can limit the biases of other board members and improve women’s ability to influence innovation. The analyses also show that the expert power of women directors has positive implications for R&D spending. More mature and powerful women can improve board decision-making by providing new ideas and perspectives that may prompt company innovation. Finally, the presence of a woman as CEO positively moderates the relationships between innovation input and both critical mass and expert power of women directors. The results therefore support the idea that CEO-board gender similarity may encourage the commitment of women directors and foster company innovation

Empirical research on nonprofit boards: main features and differences from the literature on corporate and public boards

Purpose. Recent literature on nonprofit boards of directors has extensively investigated the composition, role, responsibilities, and characteristics of boards. Given the growing number of studies on nonprofit boards, which added new impulse to the debate on the role and characteristics of these players, it is time to analyze the state of the art and systematize the current knowledge. On the other hand, despite the presence of some literature reviews, a research comparing the debate among the nonprofit, private, and public sectors is still lacking. Using Gabrielsson and Huse’s (2004) framework, we wanted to identify factors that can influence research on nonprofit boards and compare our results with existing studies on private and public sector. Methodology/Approach. We conduct a systematic literature review, selecting empirical articles published in international scientific journals from 1992 to 2012. Findings. We found similarities and differences in relation to research on boards among sectors. As a common result, we found that evolutionary studies still remains a neglected area in all of three realms. Finally, whereas input–output studies prevail in the private sector and contingency studies prevail in the public sector, behavioral studies prevail in the nonprofit sector, demonstrating, also, that the sector itself can make a difference in the board’s research. Research Limitations/Implications. This literature review provides some suggestion for further research on boards for all of three sectors. For example, we suggest complementing research on boards on all three sectors, especially in relation to evolutionary studies. Originality/Value of Paper. This paper fills the need to clarify the status of research on nonprofit boards, in order to address scholars in the understanding of the phenomenon