Yu Tanaka

Photosynthetic rate is determined by CO2 fixation and CO2 entry into the plant through pores in the leaf epidermis called stomata. However, the effect of increased stomatal density on photosynthetic rate remains unclear. This work investigated the effect of alteration of stomatal density on leaf photosynthetic capacity in Arabidopsis thaliana. Stomatal density was modulated by overexpressing or silencing STOMAGEN, a positive regulator of stomatal development. Leaf photosynthetic capacity and pla

Crop leaves are subject to continually changing light levels in the field. Photosynthetic efficiency of a crop canopy and productivity will depend significantly on how quickly a leaf can acclimate to a change. One measure of speed of response is the rate of photosynthesis increase toward its steady state on transition from low to high light. This rate was measured for seven genotypes of soybean [Glycine max (L.) Merr.]. After 10 min of illumination, cultivar 'UA4805' (UA) had achieved a leaf pho

Two-dimensional (2-D) photonic crystal (PC) directional couplers (DCs) that have a triangular lattice pattern of air holes in a planar dielectric slab are theoretically and experimentally analyzed. Unlike the 2-D PC DC structure with a dielectric rod in air, which is frequently used in theoretical studies, more practical PC DCs tend to be multimode in nature and exhibit a large group velocity dispersion, thus creating decoupling points in the dispersion relation without any additional modificati

The stomatal density (SD) can be a promising target to improve the leaf photosynthesis in soybeans (Glycine max (L.) Merr). In a conventional SD evaluation, the counting process of the stomata during a manual operation can be time-consuming. We aimed to develop a high-throughput technique for evaluating the SD and elucidating the variation in the SD among various soybean accessions. The central leaflet of the first trifoliolate was sampled, and microscopic images of the leaflet replica were obta

Leaf epidermal structure is an important determinant of leaf gas exchange in soybeans [ Glycine max (L.) Merr.] and can be used as an indirect criterion for the selection of gas exchange traits. The objective of this study was to assess the genetic variation of leaf morphology among soybean cultivars and to examine how U.S. and Japanese cultivars differ with respect to gas exchange. Over 70 cultivars, including U.S. and Japanese soybean, were grown in the field over 2 yr to determine stomatal de

The indeterminate stem growth habit resulted in a greater maximum stomatal conductance for soybean than the determinate habit, and this was attributed to the differences in leaf structure. This raises the further hypothesis that the difference in stem growth habit results in different water use characteristics of soybean plants in the field. Stomatal conductance under favourable conditions can be modified by leaf morphological traits.

Rice (<i>Oryza sativa</i> L.) is one of the most important cereals, which provides 20% of the world's food energy. However, its productivity is poorly assessed especially in the global South. Here, we provide a first study to perform a deep-learning-based approach for instantaneously estimating rice yield using red-green-blue images. During ripening stage and at harvest, over 22,000 digital images were captured vertically downward over the rice canopy from a distance of 0.8 to 0.9 m at 4,820 har

Group velocity, vg, dependence of propagation loss in single-line-defect photonic crystal waveguides on GaAs membranes, and minimum loss as low as 2.5 dB/mm, are presented. When vg is reduced by a factor of 7, an additional loss is found to be only 5 dB/mm, thus proving a feasible usage of low vg.

Photosynthesis occurs mainly in plant leaves and is a fundamental process in the global carbon cycle and in crop production. The exploitation of natural genetic variation in leaf photosynthetic capacity is a promising strategy to meet the increasing demand for crops. The present study reports the newly developed photosynthesis measurement system 'MIC-100,' with a higher throughput for measuring instantaneous photosynthetic rate in the field. MIC-100 is established based on the closed system and

Understanding the relationships between leaf photosynthetic activity and physiological and morphological traits of soybeans [ Glycine max . (L.) Merr.] with different stem growth habits could be exploited for yield improvement. Leaf photosynthetic rate (P n ), stomatal conductance (g s ), leaf mass per unit area (LMA), and leaf nitrogen content per unit area (LNC) were measured for field‐grown progeny of a cross between an indeterminate type, ‘Stressland’, and a determinate type, ‘Tachinagaha’,

The modulation characteristics of 1.3-μm InAs/GaAs high-density quantum-dot lasers is presented. The eight-stacked high-density quantum-dot layers provided high net modal gain of 46 cm-1. Fabricated Fabry-Perot lasers showed the 25-Gbps direct modulation.

In this paper, we discuss change of read range between a UHF passive RFID tag and reader when a tag is close to another tag. The read range is determined by the strength of forward link and reverse link, which are represented by received power at a tag and reader, respectively. Approaching of tags causes electromagnetic interference between antennas of tags and results in change in impedance matching condition between an antenna and IC of a tag. This change in impedance matching condition decrea

We report better spectral uniformity in Si-wire-based multistage delayed Mach-Zehnder interferometer (DMZI) type optical multiplexers/demultiplexers (MUX/DeMUX). Based on a 300 mm silicon-on-insulator wafer-scale ArF-immersion lithography process that guarantees higher phase controllability for low insertion loss, spectral flatness, and low crosstalk, we were able to further improve spectral uniformity across the wafer by optimizing the waveguide width within the optical path of each DMZI region

Enhancement of leaf photosynthetic capacity can lead to greater biomass productivity in crop plants. Targets for improving leaf photosynthetic capacity in soybean [ Glycine max (L.) Merr.], however, remain to be elucidated. The objective of this study was to identify the physiological and morphological factors underlying the diverse photosynthetic capacities of different soybean genotypes. Light‐saturated CO 2 assimilation rates ranged from 18.1 to 27.6 μmol m −2 s −1 under controlled conditions