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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2009.07.042 Byline: Ken-ichiro Hibara (a), Mari Obara (a), Emi Hayashida (a), Masashi Abe (a), Tsutomu Ishimaru (a), Hikaru Satoh (b), Jun-ichi Itoh (a), Yasuo Nagato (a) Keywords: ADAXIALIZED LEAF1 (ADL1); Phytocalpain; Adaxial-abaxial axis; Embryo development; Aleurone layer; Epidermis specification Abstract: The adaxial-abaxial axis in leaf primordia is thought to be established first and is necessary for the expansion of the leaf lamina along the mediolateral axis. To understand axis information in leaf development, we isolated the adaxialized leaf1 (adl1) mutant in rice, which forms abaxially rolled leaves. adl1 leaves are covered with bulliform-like cells, which are normally distributed only on the adaxial surface. An adl1 double mutant with the adaxially snowy leaf mutant, which has albino cells that specifically appear in the abaxial mesophyll tissue, indicated that adl1 leaves show adaxialization in both epidermal and mesophyll tissues. The expression of HD-ZIPIII genes in adl1 mutant increased in mature leaves, but not in the young primordia or the SAM. This indicated that ADL1 may not be directly involved in determining initial leaf polarity, but rather is associated with the maintenance of axis information. ADL1 encodes a plant-specific calpain-like cysteine proteinase orthologous to maize DEFECTIVE KERNEL1. Furthermore, we identified intermediate and strong alleles of the adl1 mutant that generate shootless embryos and globular-arrested embryos with aleurone layer loss, respectively. We propose that ADL1 plays an important role in pattern formation of the leaf and embryo by promoting proper epidermal development. Author Affiliation: (a) Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan (b) Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan Article History: Received 23 March 2009; Revised 9 July 2009; Accepted 20 July 2009

A new bidirectional switch and snubber circuit are proposed for medium-voltage ac/ac converters. The proposed switch can be constructed using 2-in-1 insulated-gate bipolar transistor and 2-in-1 diode modules, and can reduce the voltage stress of the switching device by series connection. The proposed snubber configuration is very simple and can regenerate absorbed energy. On the other hand, timing errors in the switching between the series-connected switches cause a voltage imbalance in the snubber circuit. Therefore, a simple method is proposed for reducing the voltage imbalance that uses one voltage sensor for each switch circuit. This proposed method controls the snubber voltages by adjusting the switch timings. Furthermore, application of the proposed switch circuit to a matrix converter is discussed and is confirmed by experiment. Index Terms--AC/AC converter, matrix converter, medium-voltage converter, series connection, snubber circuit.

Barley (Hordeum vulgare) is the fourth most highly produced cereal in the world after wheat, rice and maize and is mainly utilized as malts and for animal feed. Barley, a model crop of the tribe Triticeae, is important in comparative analyses of Poaceae. However, molecular understanding about the developmental processes is limited in barley. Our previous work characterized one of two WUSCHEL-RELATED HOMEOBOX 3 (WOX3) genes present in the barley genome: NARROW LEAFED DWARF1 (NLD1). We demonstrated that NLD1 plays a pivotal role in the development of lateral organs. In the present study, we describe a bifurcated palea (bip) mutant of barley focusing on flower and leaf phenotypes. The palea in the bip mutant was split into two and develop towards inside the lemma surrounding the carpels and anthers. The bip mutant is devoid of lodicules, which develop in a pair at the base of the stamen within the lemma in normal barley. bip also exhibited malformations in leaves, such as narrow leaf due to underdeveloped leaf-blade width, and reduced trichome density. Map-based cloning and expression analysis indicated that BIP is identical to another barley WOX3 gene, named HvWOX3. The bip nld1 double mutant presented a more severe reduction in leaf-blade width and number of trichomes. By comparing the phenotypes and gene expression patterns of various WOX3 mutants, we concluded that leaf bilateral outgrowth and trichome development are promoted by both NLD1 and HvWOX3 , but that HvWOX3 serves unique and pivotal functions in barley development that differ from those of NLD1. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2008.04.040 Byline: Masashi Abe (a), Hideaki Kuroshita (a), Masaaki Umeda (b), Jun-Ichi Itoh (a), Yasuo Nagato (a) Keywords: Flattened shoot meristem; Rice; Apical meristem; CAF-1; Cell cycle; Fasciata1 Abstract: We isolated flattened shoot meristem (fsm) mutants in rice that showed defective seedling growth and died in the vegetative phase. Since most fsm plants had flat and small shoot apical meristems (SAMs), we suggest that FSM is required for proper SAM maintenance. FSM encodes a putative ortholog of Arabidopsis FASCIATA1 (FAS1) that corresponds to the p150 subunit of chromatin assembly factor-1 (CAF-1). FSM is expressed patchily in tissues with actively dividing cells, suggesting a tight association of FSM with specific cell-cycle phases. Double-target in situ hybridization counterstained with cell-cycle marker genes revealed that FSM is expressed mainly in the G.sub.1 phase. In fsm, expressions of the two marker genes representing S- and G.sub.2- to M-phases were enhanced in SAM, despite a reduced number of cells in SAM, suggesting that S- and G.sub.2-phases are prolonged in fsm. In addition, developmental events in fsm leaves took place at the proper time, indicating that the temporal regulation of development occurs independently of the cell-cycle period. In contrast to the fasciated phenotype of Arabidopsis fas1, fsm showed size reduction of SAM. The opposite phenotypes between fsm and fas1 indicate that the SAM maintenance is regulated differently between rice and Arabidopsis. Author Affiliation: (a) Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan (b) Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan Article History: Received 20 December 2007; Revised 24 April 2008; Accepted 30 April 2008

This paper proposes a novel circuit topology for a three-phase power factor correction (PFC) rectifier using a harmonics current injection method. In consideration of lower cost, the harmonics injection method is more suitable than a conventional six-arm pulse width modulation (PWM) rectifier. The harmonics injection current is simply generated by only one switching leg. As a result, the proposed circuit has the advantage of only two switches. An optimal injection current is achieved in order to obtain an input current of sinusoidai waveforms. This paper discusses the basic operation and optimal design method for the proposed circuit. In addition, the validity of the proposed circuit is confirmed by simulation and experimental results. An input current of almost sinusoidal waveform was obtained and an input current total harmonic distortion (THD) of 8.5% was obtained at a load of approximately 1 kW. Index Terms--AC-DC power conversion, converters, harmonic distortion, power conversion harmonics, power quality, rectifiers.