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Instruction cues are widely employed for research on neural mechanisms during movement preparation. However, their influence on brain connectivity during movement has not received much attention. Herein, 15 healthy subjects completed two experimental tasks including either instructed or voluntary movements; meanwhile electroencephalogram (EEG) data were synchronously recorded. Based on source analysis and related literature, six movement-related brain regions were selected, including the left/right supplementary motor area (SMA), left/right inferior frontal gyrus (iFg), and left/right postcentral gyrus (pCg). After assuming 10 a priori models of regional brain connectivity, we evaluated the optimal connectivity model between brain regions for the two scenarios using the dynamic causality model (DCM). During voluntary movement, the movement originated in the SMA, passed through the iFg of the prefrontal lobe, and then returned to the main sensory cortex of the pCg. In the instructed movement, the movement originated in the iFg, and then was transmitted to the pCg and the SMA, as well as from the pCg to the SMA. In contrast to the preparation process of voluntary movement, there were long-range information interactions between the iFg and pCg. Further, almost the same brain regions were active during movement preparation under both voluntary and instructed movement tasks, which evidences certain similarities in dynamic brain connectivity, that is, the brain has direct connections between the bilateral SMA, bilateral pCg, and bilateral SMA, indicating that the both brain hemispheres work together during the movement preparation phase. The results suggest that the network during the preparation process of instructed movements is more complex than voluntary movements.

A new hybrid system mainly composed of a dye-sensitized solar cell (DSSC), a solar selective absorber (SSA) and an absorption heat transformer (AHT) is theoretically put forward to harness the long wavelength sunlight transmitted through the DSSC. The models of both DSSC and AHT are adopted from the current literature and the condition enables the AHT to involve in heat upgrading is obtained. The model validations of DSSC and AHT are conducted using experimental data. Mathematical expressions of power output and efficiency for the hybrid system are formulated by taking a variety of irreversible losses into account. The effectiveness of the hybrid system is justified and evaluated. Maximum power density (MPD) and maximum energy efficiency (MEE) of the integrated system are, respectively, 158.2 W m−2 and 16.3 %, having evidently improvement compared to that of a single DSSC. A variety of operating conditions and design parameters affecting the hybrid system performance are studied. Numerical calculation results show that the working temperature, photoelectron absorption coefficient of DSSC and total heat-transfer area of the AHT have positive effects on the hybrid system performance. There exists an optimum TiO2 thin film thickness to optimize the hybrid system performance. However, a greater Schottky barrier has negative influence on the hybrid system performance. The results obtained here may provide some guidance for designing such a practical hybrid system.

Starch and storage proteins are the main components of rice (Oryza sativa L.) grains. Despite their importance, the molecular regulatory mechanisms of storage protein and starch biosynthesis remain largely elusive. Here, we identified a rice opaque endosperm mutant, opaque3 (o3), that overaccumulates 57-kDa proglutelins and has significantly lower protein and starch contents than the wild type. The o3 mutant also has abnormal protein body structures and compound starch grains in its endosperm cells. OPAQUE3 (O3) encodes a transmembrane basic leucine zipper (bZIP) transcription factor (OsbZIP60) and is localized in the endoplasmic reticulum (ER) and the nucleus, but it is localized mostly in the nucleus under ER stress. We demonstrated that O3 could activate the expression of several starch synthesis-related genes (GBSSI, AGPL2, SBEI, and ISA2) and storage protein synthesis-related genes (OsGluA2, Prol14, and Glb1). O3 also plays an important role in protein processing and export in the ER by directly binding to the promoters and activating the expression of OsBIP1 and PDIL1-1, two major chaperones that assist with folding of immature secretory proteins in the ER of rice endosperm cells. High-temperature conditions aggravate ER stress and result in more abnormal grain development in o3 mutants. We also revealed that OsbZIP50 can assist O3 in response to ER stress, especially under high-temperature conditions. We thus demonstrate that O3 plays a central role in rice grain development by participating simultaneously in the regulation of storage protein and starch biosynthesis and the maintenance of ER homeostasis in endosperm cells.

A new hybrid system model comprised of a concentrated photovoltaic cell (CPC) and an elastocaloric cooler (ECC) is proposed, where the ECC is driven by the thermal energy from CPC that cannot be converted into electrical energy. Mathematical expression between the exhaust heat of CPC and the operating electric current as well as the time required for one cycle are derived. Mathematical formulas for the power output and efficiency of CPC and proposed system and the cooling rate and efficiency of ECC are specified. Calculations show that maximum energy efficiency (MEE) and maximum power density (MPD) of hybrid system are, respectively, 20.20 % and 767.47 W m−2 larger than that of the CPC alone. A variety of design parameters and operating conditions affecting the hybrid system performance are studied. Numerical calculation results show that the environmental temperature, solar irradiation, concentration ratio and cross-sectional area ratio of CPC as well as length ratio are helpful to improve the hybrid system performance. The results obtained are helpful to optimally design and run such a real CPC/ECC hybrid system.

A new cogeneration system model that integrates a concentrated photovoltaic cell (CPV) and a two-stage thermoelectric generator (TTEG) considering the Peltier, Seebeck and Thomson effects is proposed, where the CPV converts the inlet solar energy into electricity and heat, and the TTEG further harvests the heat for additional electricity production. Mathematical relation of the operating electric currents between TTEG and CPV is determined. Mathematical formulas for the power output and efficiency of the proposed system are specified under different operation conditions. The maximum power density (MPD) and maximum energy efficiency (MEE) of the proposed hybrid system are about 8% greater than that of the stand-alone CPV, respectively. Furthermore, the impacts of the operating temperature of CPV, solar irradiance, concentration ratio, thermocouple number ratio between top-stage and bottom-stage, total number of thermocouple and different thermoelectric materials on the hybrid system performance are revealed. The results may provide some new insights into designing such an efficient solar-to-electricity hybrid system.