Interpreting lemma and palea homologies: a point of view from rice floral mutants

In contrast to eudicot flowers which typically exhibit sepals and petals at their periphery, the flowers of grasses are distinguished by the presence of characteristic outer organs. In place of sepals, grasses have evolved the lemma and the palea, two bract-like structures that partially or fully enclose the inner reproductive organs. With little morphological similarities to sepals, whether the lemma and palea are part of the perianth or non-floral organs has been a longstanding debate. In recent years, comparative studies of floral mutants as well as the availability of whole genome sequences in many plant species have provided strong arguments in favor of the hypothesis of lemma and palea being modified sepals. In rice, a feature of the palea is the bending of its lateral region into a hook-shaped marginal structure. This allows the palea to lock into the facing lemma region, forming a close-fitting lemma-palea enclosure. In this article, we focus on the rice lemma and palea and review some of the key transcription factors involved in their development and functional specialization. Alternative interpretations of these organs are also addressed

Influence on uncertainty of earthquake response analysis results by initial particle arrangements and cohesion parameters in extended distinct element method

Following the occurrence of extremely large earthquakes, such as the Great East Japan Earthquake, the level of design for earthquake ground motion in nuclear power plants has been enhanced. Additionally, the quantitative evaluation of the seismic performance of critical facilities, such as nuclear power plants, and earthquake-induced failure of surrounding slopes are becoming increasingly important as deterministic approaches in regulation. However, evaluation of other aspects besides the design for earthquake ground motion in probabilistic risk assessment (PRA) needs to be conducted voluntarily by the corporation. For the earthquake response analysis, including the seamless transition of the slope from continuum to dis-continuum, the extended distinct element method (EDEM) is an effective approach; however, EDEM is characterised by initial particle arrangement uncertainty. Therefore, we investigated the uncertainty in the EDEM results with respect to failure timing and region. Although essential in the evaluation of impact force in the PRA framework, there are few researches regarding the uncertainty of impact force on the wall of the reactor building after slope failure caused by numerous initial particle arrangements. Furthermore, reducing the computational time is crucial in PRA. Hence, the parameters that do not have an influence on the EDEM results can be omitted, resulting in their dispersion and a reduction in the computational time. This research aims to investigate the impact force uncertainty caused by initial particle arrangements and the influence of cohesion uncertainty. For the former, we conducted 50 numerical simulations for the uncertainty of EDEM results caused by the initial particle arrangements. For the latter, we conducted 50 numerical simulations with two uncertainty factors, namely, cohesion and initial particle arrangement. The simulation results revealed that the largest and second largest loads on the wall occurred in two cases, namely, when there were single particles impacting the wall and when there were group particles impacting the wall. Additionally, the uncertainty caused by cohesion was less than that arrangement when the coefficient of variation was 0.1. Thus, the cohesion uncertainty can be ignored if it is somewhat small

Generic transport coefficients of a confined electrolyte solution

Physical parameters characterising electrokinetic transport in a confined electrolyte solution are reconstructed from the generic transport coefficients obtained within the classical non-equilibrium statistical thermodynamic framework. The electro-osmotic flow, the diffusio-osmotic flow, the osmotic current, as well as the pressure-driven Poiseuille-type flow, the electric conduction, and the ion diffusion, are described by this set of transport coefficients. The reconstruction is demonstrated for an aqueous NaCl solution between two parallel charged surfaces with a nanoscale gap, by using the molecular dynamic (MD) simulations. A Green-Kubo approach is employed to evaluate the transport coefficients in the linear-response regime, and the fluxes induced by the pressure, electric, and chemical potential fields are compared with the results of non-equilibrium MD simulations. Using this numerical scheme, the influence of the salt concentration on the transport coefficients is investigated. Anomalous reversal of diffusio-osmotic current, as well as that of electro-osmotic flow, is observed at high surface charge densities and high added-salt concentrations.Comment: 6 pages with 6 figure

Grouting in Consideration of Predominant Direction of Joints in Rock Masses

We conducted a grouting test in rock mass having steep joints with predominant direction, assuming blanket grouting for embankment dams. Vertical holes and inclined holes designed in consideration of the predominant direction of the joints were used as grouting holes, and the hole spacing was determined such that the number of grouting holes per unit area on a joint was the same for both cases. As a result, both tests saw a similar improvement despite the fact that the test using inclined holes had wider hole spacing than the test using vertical holes on the ground surface. We can also reduce the total drilling length of grouting holes if we use inclined holes instead of vertical holes, the hole spacing of which is determined in this manner, and thus we have demonstrated the usefulness of grouting that considers the predominant direction of joints in rock mass