José Marcos Alonso Álvarez

Microcontroller-Based High-Power-Factor Electronic Ballast to Supply Metal Halide Lamps

The analysis, design, and implementation of a microcontroller-based electronic ballast to supply metal halide (MH) lamps are presented. The proposed topology is based on the integration of the buck and flyback converters, the former providing power factor correction and the latter controlling lamp power. The lamp is supplied by a low-frequency square-waveform current, which is a convenient way to avoid acoustic resonances in high-intensity discharge lamps. Both converters operate in discontinuous conduction mode, thus allowing the use of only one high-frequency switch and simplifying the control. The electronic ballast is digitally controlled by using a low-cost microcontroller PIC16F684. The microcontroller performs all the necessary tasks during starting, warming-up, and steady state, including closed-loop control of lamp current and protections. The closed-loop control takes into account the lamp dynamical impedance. Experimental results for a 35-W MH lamp are presented, and the obtained overall efficiency is 90%.

Stable Agrobacterium-mediated transformation of maritime pine based on kanamycin selection.

An efficient transformation protocol based on kanamycin selection was developed for Agrobacterium-mediated transformation of maritime pine embryonal masses. The binary vector pBINUbiGUSint, which contained neomycin phosphotransferase II (nptII) as a selectable marker gene and β-glucuronidase (uidA) as a reporter gene, was used for transformation studies. Different factors, such as embryogenic line, bacterial strain, bacterial concentration, and coculture duration, were examined and optimized. For selection of transformants, 15 mgL−1 kanamycin was used. The highest transformation efficiency (11.4 events per gram of fresh mass) was achieved when a vigorously growing embryonal mass (embryogenic line L01) was cocultivated with Agrobacterium strain AGL1 at the optical density (OD600 nm) of 0.3 for 72 h. Evidence of the stable transgene integration was obtained by polymerase chain reaction for the nptII and uidA genes and expression of the uidA gene. Maturation capacity of the transgenic lines was negatively affected by the transformation process. Induction of axillary shoots by preculturing the embryos with benzyladenine allowed overcoming the low maturation rates of some transformed lines. The transgenic embryos were germinated and the axillar shoots were rooted. Transgenic plants were transferred to potting substrate showing normal growth.

Programmed cooling control of a batch crystallizer

Abstract A dynamic model of the evolution of the temperature of a batch cooling crystallizer has been used for the development of a Generic Model Control (GMC) system: for the crystallizer. This servo-control system has been found experimentally to work adequately. The crystallizer has also been controlled with a conventional PI controller, and the process has been simulated with the model. Simulations are accurate enough to allow the model to be used for the design of control strategies for programmed cooling crystallizers. The methodology described can be adapted to the study of other systems or control algorithms.

Improving plantlet yield in Pinus pinaster somatic embryogenesis

Abstract Somatic embryogenesis is expected to play a significant role in the future forest tree improvement programmes. The main bottleneck of this technique is still the progression from immature embryogenic cultures to mature cotyledonary embryos able to develop properly into well-growing plants. In this work, we present an improved protocol focused on increasing the maturation and conversion rate of Pinus pinaster Ait. embryogenic cultures. Results showed that the optimisation of the nutrient composition in the maturation medium increased the number of mature embryos by 25% (187.8 embryos per gram of fresh mass in average compared to 144.5 embryos in regular medium). It was also shown that 12-month cryostorage did not reduce viability or embryogenic ability of maritime pine cultures. A further increase in the yield of the protocol could be obtained by using benzyladenine in the conversion medium, promoting the bud-break of axillary buds that yielded 5.7 shoots in average per somatic embryo. Rooting of axillary shoots reached 84.3%. This methodology offers an alternative to overcome some problems associated with low somatic embryo production since the plantlet yield could be increased fivefolds.

CLAVATA1-LIKE, a leucine-rich-repeat protein receptor kinase gene differentially expressed during adventitious caulogenesis in Pinus pinaster and Pinus pinea

Molecular cloning and characterization of a CLAVATA1-LIKE gene in Pinus pinaster and Pinus pinea is reported. CLAVATA1 is a well-characterized gene in Arabidopsis integral to the balance between primordial differentiation and meristem proliferation. Currently, it is not known if the Arabidopsis model of in vitro caulogenesis is applicable to conifers. In this work, we study the putative role of the CLAVATA1-LIKE gene during caulogenic induction in cotyledons of P. pinea and P. pinaster after exposure to benzyladenine. Expression analysis showed that the gene was differentially expressed during the first phases of adventitious caulogenesis in cotyledons from both species, suggesting that CLAVATA1-LIKE may play a role in caulogenesis in conifers. A binary vector carrying CLAVATA1-LIKE promoter driven GFP:GUS expression was constructed. Results of genetic transformation showed GUS activity during somatic embryogenic mass proliferation and embryo maturation.

Characterization of a type-A response regulator differentially expressed during adventitious caulogenesis in Pinus pinaster

The molecular cloning and characterization of PipsRR1, a type-A response regulator in Pinus pinaster, is reported here. Type-A response regulators mediate downstream responses to cytokinin and act as negative feedback regulators of the signal transduction pathway. Some type-A response regulators in Arabidopsis have been related to de novo meristem formation. However, little information exists in Pinus spp. The PipsRR1 gene contains 5 exons, as do all type-A response regulators in Arabidopsis, and the deduced protein contains a receiver domain with the conserved DDK residues and a short C terminal extension. Expression analysis showed that the PipsRR1 gene is differentially expressed during the first phases of adventitious caulogenesis induced by benzyladenine in P. pinaster cotyledons, suggesting that PipsRR1 plays a role in caulogenesis in conifers. Additionally, a binary vector carrying the PipsRR1 promoter driving GFP:GUS expression was constructed to analyze the promoter activity in P. pinaster somatic embryos. The results of genetic transformation showed GUS activity during somatic embryo mass proliferation and embryo maturation.

Cloning and characterization of a type-A response regulator differentially expressed during adventitious shoot formation in Pinus pinea L.

Type-A response regulators play an important role in cytokinin-induced adventitious shoot formation, acting as negative regulators of cytokinin signal transduction. In this work, we obtained the full-length cDNA clone of a type-A response regulator from the conifer Pinus pinea, designated PipiRR1. The derived peptide sequence showed all the characteristic motifs found in angiosperms. Gene expression analysis showed that the gene was differentially expressed during adventitious shoot formation in P. pinea cotyledons, suggesting that PipiRR1 may play a role in caulogenesis in conifers. This is the first type-A response regulator identified in gymnosperms.

Analysis of the WUSCHEL-RELATED HOMEOBOX gene family in Pinus pinaster: New insights into the gene family evolution

WUSCHEL-RELATED HOMEOBOX (WOX) genes are key players controlling stem cells in plants and can be divided into three clades according to the time of their appearance during plant evolution. Our knowledge of stem cell function in vascular plants other than angiosperms is limited, they separated from gymnosperms ca 300 million years ago and their patterning during embryogenesis differs significantly. For this reason, we have used the model gymnosperm Pinus pinaster to identify WOX genes and perform a thorough analysis of their gene expression patterns. Using transcriptomic data from a comprehensive range of tissues and stages of development we have shown three major outcomes: that the P. pinaster genome encodes at least fourteen members of the WOX family spanning all the major clades, that the genome of gymnosperms contains a WOX gene with no homologues in angiosperms representing a transitional stage between intermediate- and WUS-clade proteins, and that we can detect discrete WUS and WOX5 transcripts for the first time in a gymnosperm.

Single Stage High Power Factor Electronic Ballast for HID Lamps Using Differential Connection

This paper presents an electronic ballast topology for HID lamps using differential connection of DC/DC converters. The integration of power factor correction, lamp power control and inverter stages results in a single-stage electronic ballast that supplies the lamp with a low frequency symmetrical square voltage waveform, which avoids both the acoustic resonance phenomenon excitation and the lamp restarting. The ballast consists of a buckboost power factor correction converter and two bidirectional flyback converters connected to the lamp in a differential way. These converters are combined using only two switches that share the same source reference, thus resulting in a simple control circuit.

Synthesis of 2-morpholinopenta-3,4-dienal derivatives and propargyloxyenamines by catalytic aminomercuration of dipropargyl ethers

Abstract Propargyloxyenamines and/or 2-morpholinopenta-3,4-dienal derivatives are obtained by catalytic aminomercuration of dipropargyl ethers depending on their substituents.