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Highlights • Bulb size decreased from earliest to latest planting in spring-sowing cultivation. • Temperature affected leaf initiation, leaf number (associated to final bulb size). • Plant growth and bulb size increased in proportion to accumulated temperature. • Choice of cultivar and sowing time are important to reach production potential. Abstract Bulb size is an important factor in determining the productivity of onion (Allium cepa L.), and production of suitable bulb sizes is a priority objective in cultivation. Previous studies have reported that bulb development is controlled by photoperiod and temperature. Although many studies have investigated the influence of day length on bulb development, the effect of temperature has not received as much attention. It has been shown that transplanting time strongly affects bulb size, and our study showed that crop yield and bulb size of four commercially used cultivars in Japan significantly decreased from the earliest to the latest sowing in spring-sowing cultivation. This phenomenon was investigated using the commercially used onion cultivar 'Momiji No. 3' and a temperature gradient growth chamber, and our study revealed that a high temperature inhibited leaf initiation and decreased leaf number, which preceded bulb development and was closely related to final bulb size. We also show that plant growth, including parameters such as total leaf number, stem diameter, and bulb diameter, fresh, and dry weight, linearly increased with increasing accumulated temperature, which was calculated from the integrated values of the daily mean temperature; growth was suggested to have a strong positive correlation with temperature because the r -values were greater than 0.9. Therefore, for onion production, apart from choosing a suitable cultivar and sowing time for each production area, to attain the production potential of each cultivar it is important that an optimal temperature is maintained during plant growth and bulb development. [ABSTRACT FROM AUTHOR]

We investigated the use of a simplified soilless tomato culture system fertilized with controlled-release fertilizers (CRF) in northern Japan. The utility of this system was assessed by measuring plant growth, fruit yield, yield components, light interception by plant canopy and nutrient use during August–January. Five levels of fertilizer (5–15 g N per plant) were applied using CRF in a closed system and these were compared with plants given liquid fertilizer (LF) with an electrical conductivity (EC) control in an open system. The CRF was supplied in a water recirculation tank. Total N supply in the LF system (19.7 g N per plant) was higher than in the CRF treatments. In the latter, fresh fruit yield increased with higher fertilizer levels up to 12.5 g N. The fruit yields at 12.5 and 15.0 g N were similar to those with the LF system. The high fresh fruit yield was caused by high dry matter yield regardless of the CRF treatments, which showed similar dry matter distribution to fruit. A high correlation was noted between cumulative light interception and total dry matter production. Although both were high, dry matter distribution to fruit was lower in the LF system than in the CRF treatments. Overall, however, these effects resulted in similar dry and fresh fruit yields between CRF and LF treatments, with excessive vegetative growth in the LF system. We conclude that the closed CRF application system reduced 37% of nutrient use but still gave a fruit yield equivalent to that obtained by culturing with the open LF system and EC-based management. [ABSTRACT FROM AUTHOR]

To further development of a simplified fertigation system using controlled-release fertilizers (CRF), we investigated the effects of differing levels of fertilizers and plant density on leaf area index (LAI), fruit yields, and nutrient use in soilless tomato cultures with low node-order pinching and high plant density during spring-summer (SS), summer-fall (SF), and fall-winter (FW) seasons. Plants were treated with 1 of 3 levels of CRF in a closed system, or with liquid fertilizer (LF) with constant electrical conductivity (EC) in a drip-draining system. Two plant densities were examined for each fertilizer treatment. In CRF treatments, LAI at pinching increased linearly with increasing nutrient supply for all cropping seasons. In SS, both light interception by plant canopy at pinching and total marketable fruit yield increased linearly with increasing LAI up to 6 m2·m−2; the maximization point was not reached for any of the treatments. In FW, both light interception and yield were maximized at an LAI of approximately 4. These results suggest that maximizing the LAI in SS and FW to the saturation point for light interception is important for increasing yield. In SF, however, the yield maximized at an LAI of approximately 3, although the light interception linearly increased with increasing LAI, up to 4.5. According to our results, the optimal LAI at pinching may be 6 in SS, 3 in SF, and 4 in FW. In comparing LAI values with similar fruit yield, we found that nutrient supply was 32−46% lower with the CRF method than with LF. In conclusion, CRF application in a closed system enables growers to achieve a desirable LAI to maximize fruit yield with a regulated amount of nutrient supply per unit area. Further, the CRF method greatly reduced nutrient use without decreasing fruit yield at similar LAIs, as compared to the LF method. [ABSTRACT FROM AUTHOR]

Application of controlled-release fertilizer (CRF) to root-proof capillary-wick irrigation systems (a type of subirrigation method) has both economic and environmental benefits because it does not require any equipment for fertigation and minimizes water leaching. In this study, we compared three CRF fertilization methods: 1) mixed with the substrate completely ["mixed-fertilization" (MF)]; 2) packed in bags and placed on the wick ["packed bag-fertilization" (PF)]; and 3) supplied in the water reserve tank ["tank-fertilization" (TF)] in tomato cultivation using the root-proof capillary-wick irrigation system. We also refined the TF method to simplify and reduce labor requirements for fertilization of CRF and reuse of substrate. Fruit yield was lower in PF and TF than in MF because of high incidence of blossom-end rot (BER) in PF and TF during both cultivation periods, spring ù summer and fall ùwinter. However, promotion of nitrification in TF by supplying nitrogen through the addition of bark compost and aeration of the water reserve tank increased fruit yield to the same level as that observed in MF as a result of a decrease in BER incidence. Nutrient residue in the substrate was lower in TF than in MF. On the basis of the analysis of nitrogen concentration in xylem exudates, the uptake ratio of NH4-N/NO3-N was thought to be lower in MF than in PF and TF. The high NH4-N uptake in PF and TF could be the cause of calcium (Ca) deficiency and increased incidence of BER. Thus, the use of "tank fertilization" of CRF in the root-proof capillary-wick irrigation system for tomato production is possible by promoting nitrification in the water reserve tank. [ABSTRACT FROM AUTHOR]

Application of controlled-release fertilizer (CRF) to a root-proof capillary wick irrigation system (a type of subirrigation method) has both economical and environmental benefits, because it does not require any equipment for fertigation and minimizes water leaching. In this study, we examined the effects of CRF and liquid fertilizer (LF), a conventional fertigation method, on fruit production and nutrient uptake and transport in forcing tomato cultures for harvesting 15 trusses per plant from October to June. No significant difference was noted in marketable fruit yield between CRF- and LF-treated plants. The quantity of nutrient uptake per plant and per fruit yield was lower with CRF than with LF, indicating that nutrients were used more efficiently for fruit production in plants grown with CRF. Analysis of the volume and mineral concentrations of xylem exudates indicated that the amount of nutrients absorbed was greater with LF than with CRF, particularly after the tenth truss was harvested. Mineral concentrations in the substrate solution of CRF-treated plants were initially higher than those in the substrate solution of LF-treated plants but extremely low after the second truss was harvested, whereas mineral concentrations in the xylem exudates were similar in CRF and LF plants until the eighth truss was harvested. Thus, the difference in mineral concentrations between the xylem exudates and substrate solution was much larger in the case of CRF than in the case of LF, indicating that the plants absorbed the bulk of nutrients immediately after their release from the CRF surface. Therefore, CRF is suitable in this system, because it combines high fruit production with high nutrient utilization efficiency. [ABSTRACT FROM AUTHOR]

In order to improve direction stability of a power wheelchair on a cross-sloped surface, a downhill turning prevention control (DTPC) has been developed by some researchers and wheelchair suppliers. The DTPC-induced effect on wheelchair maneuver, however, has not been well clarified. In this study, we quantitatively assessed DTPC-induced changes in joystick control strategies during a driving task on a cross-sloped test course. Among several evaluation measures calculated from the joystick inputs during the test trials, the x-axis joystick displacement amount was found to be significantly decreased by the DTPC. This result suggests that the DTPC can save wheelchair users from the burden of compensation control on cross-sloped surfaces. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Abstract: A method for incorporating BT nano-crystalline into barium titanate (BT) films is proposed for a low temperature fabrication of high dielectric constant films. BT nanoparticles were synthesized by hydrolysis of a BT complex alkoxide in 2-methoxyethanol (ME)/ethanol cosolvent. As the ME volume fraction in the cosolvent (ME fraction) increased from 0 to 100%, the particle and crystal sizes tended to increase from 13.4 to 30.2nm and from 15.8 to 31.4nm, respectively, and the particle dispersion in the solution became more improved. The BT particles were mixed with BT complex alkoxide dissolved in an ME/ethanol cosolvent for preparing a precursor solution that was then spin-coated on a Pt substrate and dried at 150°C. The dielectric constant of the spin-coated BT hybrid film increased with an increase in the volume fraction of the BT particles in the film. The dissipation factor of the hybrid film tended to decrease with an increase in the ME fraction in the precursor solution. The hybrid film fabricated at a BT fraction of 30% and an ME fraction of 25% attained a dielectric constant as high as 94.5 with a surface roughness of 14.0nm and a dissipation factor of 0.11. [ABSTRACT FROM AUTHOR]

The R-R interval (RRI) fluctuation in electrocardiogram (ECG) is called heart rate variability (HRV), which reflects activities of the autonomic nervous system (ANS) and has been used for various health monitoring services. Accurate R wave detection is crucial for success in HRV-based health monitoring services; however, ECG artifacts often cause missing R waves and deteriorate the accuracy of HRV analysis. The present work proposes a new missing RRI interpolation technique based on Just-In-Time (JIT) modeling. In the JIT modeling framework, a local regression model is built by weighing samples stored in the database according to the distance from a query and output is estimated only when an estimate is requested. The proposed method builds a local model and estimates missing RRI only when an RRI detection error is detected. Locally weighted partial least squares (LWPLS) is adopted for local model construction. The proposed method is referred to as LWPLS-based RRI interpolation (LWPLS-RI). The performance of the proposed LWPLS-RI was evaluated through its application to RRI data with artificial missing RRIs. We used the MIT-BIH Normal Sinus Rhythm Database for nominal RRI dataset construction. Missing RRIs were artificially introduced and they were interpolated by the proposed LWPLS-RI. In addition, MEAN that replaces the missing RRI by a mean of the past RRI data was compared as a conventional method. The result showed that the proposed LWPLS-RI improved root mean squared error (RMSE) of RRI by about 70% in comparison with MEAN. In addition, the proposed method realized precise HRV analysis. The proposed method will contribute to the realization of precise HRV-based health monitoring services. [ABSTRACT FROM AUTHOR]