Output voltage estimation of a half-bridge inverter for domestic induction heating applications

The power supplied to a vessel by a domestic induction-heating appliance is strongly dependent on several parameters the designer of the system has no control over: the type and the size of the vessel, misalignments between the pot and the inductor, temperatures, etc. A reliable estimation of the power is essential to ensure that the home appliance works under the expected conditions and the user experience is suitable. Furthermore, any reduction of hardware is totally welcome by consumer-electronics manufacturers. In this work, two methods to estimate the output voltage of a half-bridge inverter without digitizing it with an analog-to-digital converter are proposed and the effects that this estimation has on the power calculation are evaluated. Both methods are implemented and experimentally verified in a real prototype with an FPGA (Field-Programmable Gate Array)

Outstanding Questions in Flower Metabolism

The great diversity of flowers, their color, odor, taste, and shape, is mostly a result of the metabolic processes that occur in this reproductive organ when the flower and its tissues develop, grow, and finally die. Some of these metabolites serve to advertise flowers to animal pollinators, other confer protection towards abiotic stresses, and a large proportion of the molecules of the central metabolic pathways have bioenergetic and signaling functions that support growth and the transition to fruits and seeds. Although recent studies have advanced our general understanding of flower metabolism, several questions still await an answer. Here, we have compiled a list of open questions on flower metabolism encompassing molecular aspects, as well as topics of relevance for agriculture and the ecosystem. These questions include the study of flower metabolism through development, the biochemistry of nectar and its relevance to promoting plant‐pollinator interaction, recycling of metabolic resources after flowers whiter and die, as well as the manipulation of flower metabolism by pathogens. We hope with this review to stimulate discussion on the topic of flower metabolism and set a reference point to return to in the future when assessing progress in the field

Botrytis cinerea loss and restoration of virulence during in vitro culture follows flux in global DNA methylation

Pathogenic fungi can lose virulence after protracted periods of culture, but little is known of the underlying mechanisms. Here, we present the first analysis of DNA methylation flux at a single-base resolution for the plant pathogen B. cinerea and identify differentially methylated genes/genomic regions associated with virulence erosion during in vitro culture. Cultures were maintained for eight months, with subcultures and virulence testing every month. Methylationsensitive amplified polymorphisms were performed at monthly intervals to characterise global changes to the pathogen’s genome during culture and also on DNA from mycelium inoculated onto Arabidopsis thaliana after eight months in culture. Characterisation of culture-induced epialleles was assessed by whole-genome re-sequencing and whole-genome bisulfite sequencing. Virulence declined with time in culture and recovered after inoculation on A. thaliana. Variation detected by methylation-sensitive amplified polymorphisms followed virulence changes during culture. Wholegenome (bisulfite) sequencing showed marked changes in global and local methylation during culture but no significant genetic changes. We imply that virulence is a non-essential plastic character that is at least partly modified by the changing levels of DNA methylation during culture. We hypothesise that changing DNA methylation during culture may be responsible for the high virulence/low virulence transition in B. cinerea and speculate that this may offer fresh opportunities to control pathogen virulence.James Breen, Luis Alejandro Jose Mur, Anushen Sivakumaran, Aderemi Akinyemi, Michael James Wilkinson, and Carlos Marcelino Rodriguez Lope

Germline mutations in the spindle assembly checkpoint genes BUB1 and BUB3 are infrequent in familial colorectal cancer and polyposis

Contains fulltext : 190008.pdf (publisher's version ) (Open Access

Inhibition of flower pigmentation by antisense CHS genes: promoter and minimal sequence requirements for the antisense effect

Introduction of a constitutive antisense full-length chalcone synthase (CHS) cDNA gene in petunia can result in an inhibition of flower pigmentation. We have evaluated some of the factors which may be important for the effectiveness of an antisense CHS gene. Antisense CHS genes encoding half-length or quarter-length RNA complementary to the 3′ half of CHS mRNA are able to affect flower pigmentation, while a gene encoding RNA complementary to the 5′ half of CHS mRNA did not show phenotypic effects in transgenic petunia plants. We demonstrate that the RNA encoded by the latter gene has a much lower average steady-state level in leaf tissue than the RNAs encoded by the other antisense gene constructs. We have compared the CaMV 35S and endogenous CHS promoter strengths and intrinsic stabilities of sense and antisense CHS RNAs. From the data we conclude that the constitutive antisense CHS genes are not likely to provide an excess of antisense RNA compared to the CHS mRNA derived from the endogenous genes. Effective inhibition of flower pigmentation is also observed when the antisense CHS gene is under control of the homologous CHS promoter. The results indicate that the mechanism of antisense inhibition cannot solely operate via RNA duplex formation between sense and antisense RNA. © 1990 Kluwer Academic Publishers

Antisense chalcone synthase genes in petunia: Visualization of variable transgene expression

The constitutive expression of an antisense chalcone synthase (CHS) gene in transgenic petunia plants results with high frequency in a reduced flower pigmentation due to a reduction in the CHS mRNA steady-state level in floral tissue. Here we show that this reduction is specific for CHS mRNA; chalcone flavanone isomerase (CHI) and dihydroflavonol reductase (DFR) mRNA steady-state levels are unaffected. However, in white floral tissue a severe reduction in CHI specific activity is found, accompanied by an altered signal for CHI protein on western blots. We find no correlation between the phenotypic effect of the antisense CHS gene and its chromosomal position. For some of the antisense CHS transformants the flower phenotype is highly variable. We demonstrate that pigmentation in these plants can be influenced by gibberellic acid and light, suggesting that the variable flower phenotype is caused by changes in physiological conditions during flower development. The results not only indicate that flower pigmentation in these plants reveals the variable expression of the antisense transgene, but also show that genomic sequences flanking the transgene may render its expression extremely susceptible to physiological conditions. © 1990 Springer-Verlag

The ALHAMBRA survey: tight dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5

International audienceAims. Our goal is to characterise the dependence of the optical mass-to-light ratio on galaxy colour up to z = 1.5, expanding the redshift range explored in previous work.Methods. From the redshifts, stellar masses, and rest-frame luminosities of the ALHAMBRA multi-filter survey, we derive the mass-to-light ratio versus colour relation for quiescent and for star-forming galaxies. The intrinsic relation and its physical dispersion are derived with a Bayesian inference model.Results. The rest-frame i-band mass-to-light ratio of quiescent and star-forming galaxies presents a tight correlation with the rest-frame (g − i) colour up to z = 1.5. The mass-to-light ratio versus colour relation is linear for quiescent galaxies and quadratic for star-forming galaxies. The intrinsic dispersion in these relations is 0.02 dex for quiescent galaxies and 0.06 dex for star-forming ones. The derived relations do not present a significant redshift evolution and are compatible with previous local results in the literature. Finally, these tight relations also hold for g- and r-band luminosities.Conclusions. The derived mass-to-light ratio versus colour relations in ALHAMBRA can be used to predict the mass-to-light ratio from a rest-frame optical colour up to z = 1.5. These tight correlations do not change with redshift, suggesting that galaxies have evolved along the derived relations during the last 9 Gyr.Key words: galaxies: fundamental parameters / galaxies: statistics / galaxies: stellar content⋆ Based on observations collected at the German-Spanish Astronomical Centre, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie (MPIA) at Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC)