Attrition milling is an easily scalable and environmentally friendly process used to produce Ca3Co4O9+δ nanoprecursors in a relatively short time. Sintered materials produced through the classical solid-state method, involving ball... more
Attrition milling is an easily scalable and environmentally friendly process used to produce Ca3Co4O9+δ nanoprecursors in a relatively short time. Sintered materials produced through the classical solid-state method, involving ball milling, show much larger grain sizes and slightly lower density than those obtained in samples produced from attrition-milled precursors. On the other hand, electrical resistivity has been drastically decreased, accompanied with a slight decrease in the Seebeck coefficient in samples obtained from these attrition-milled precursors. Moreover, the use of an attrition milling process leads to a very important reduction in processing time (around 75%), together with a slight power factor improvement of around 10%, when compared to the classically prepared samples.
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We have isolated three female-specific lethal mutations at the gene Sex-lethal (Sxl): Sxlfb, Sxlfc and Sxlfd. We have carried out the complementation analysis between these mutations and other previously reported Sxlf mutations. It is... more
We have isolated three female-specific lethal mutations at the gene Sex-lethal (Sxl): Sxlfb, Sxlfc and Sxlfd. We have carried out the complementation analysis between these mutations and other previously reported Sxlf mutations. It is possible to classify the alleles tested in this report into two complementation groups: the bc group defined by Sxlfb, and Sxlfc, and the LS group defined by SxlfLS. The other alleles tested affect both complementation groups albeit with different degrees. Contrary to what happens with mutations at the LS group, mutations at the bc group do not affect sex determination, nor late dosage compensation nor oogenesis. Both Sxlfb and Sxlfc present a DNA insertion of at least 5 kb between position -10 and -11 on the molecular map, within the fourth intron. On the contrary, Sxlfd, a strong mutation affecting all Sxl functions, is not associated to any detectable DNA alteration in Southern blots, so that it seems to be a "point" mutation. In agreement...
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Soil microorganisms surviving in mining sites have developed metal‐resistance mechanisms to biotransform metals. Their use as biofertilizers can improve phytoremediation efficiency in contaminated soils by reducing metal toxicity while... more
Soil microorganisms surviving in mining sites have developed metal‐resistance mechanisms to biotransform metals. Their use as biofertilizers can improve phytoremediation efficiency in contaminated soils by reducing metal toxicity while promoting plant growth. We analysed through whole‐metagenome shotgun sequencing the composition, diversity and function of microbial communities present in a contaminated mine soil along a gradient of metals (As, Cu, Fe, Mn, Pb, Zn) to identify tolerant species carrying metal‐resistance functional genes that can be used in association with plants for phytoremediation. Soil samples were collected from an abandoned copper mine, across three areas with different levels of metal contamination (unaffected, moderately contaminated and highly contaminated). The relative abundance of Proteobacteria, especially genus Bradyrhizobium, increased in the highly contaminated area, whereas Actinobacteria dominated in the unaffected area. Archaea (Euryarchaeota) predo...
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In this study, Ca0.9Yb0.1MnO3 + x wt.% Ag (with x = 0, 1, 3, 5, and 10) thermoelectric materials were prepared via the classical ceramic method. In spite of the very high sintering temperature (1300 °C), no significant Ag losses were... more
In this study, Ca0.9Yb0.1MnO3 + x wt.% Ag (with x = 0, 1, 3, 5, and 10) thermoelectric materials were prepared via the classical ceramic method. In spite of the very high sintering temperature (1300 °C), no significant Ag losses were observed following this process. Moreover, Ag addition enhanced cation mobility during sintering due to the formation of a liquid phase. Microstructurally, it was found that Ag decreases porosity; this was confirmed by density measurements. Ag was also found to promote the formation of a Ca2Mn2O5 secondary phase. Despite the presence of this secondary phase, samples with Ag displayed lower electrical resistivity than Ag-free ones, without a drastic decrease in the absolute Seebeck coefficient. The highest thermoelectric performances, which were determined by power factor, were obtained in 1 wt.% Ag samples. These maximum values are slightly higher than the best of those reported in the literature for sintered materials with similar compositions, with th...
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Codeinone reductase (COR) catalyzes the reversible NADPH-dependent reduction of codeinone to codeine as the penultimate step of morphine biosynthesis in opium poppy (Papaver somniferum). COR also irreversibly reduces neopinone, which... more
Codeinone reductase (COR) catalyzes the reversible NADPH-dependent reduction of codeinone to codeine as the penultimate step of morphine biosynthesis in opium poppy (Papaver somniferum). COR also irreversibly reduces neopinone, which forms by spontaneous isomerization in aqueous solution from codeinone, to neopine. In a parallel pathway involving 3-O-desmethylated analogs, COR converts morphinone to morphine, and neomorphinone to neomorphine. Similar to neopine, neomorphine formation by COR is irreversible. Neopine is a minor substrate for codeine O-demethylase (CODM) yielding morphine. In the plant, neopine levels are low and neomorphine has not been detected. Silencing of CODM leads to accumulation of upstream metabolites, such as codeine and thebaine, but does not result in a shift towards higher relative concentrations of neopine, suggesting a plant mechanism for limiting neopine production. In yeast (Saccharomyces cerevisiae) engineered to produce opiate alkaloids, the catalyti...
Research Interests: Biochemistry, Plant Biology, Biology, Medicine, Plant, and 3 moreThebaine, Opium Poppy, and Papaver Plant
Benzylisoquinoline alkaloids (BIAs) are produced in a wide variety of plants and include many common analgesic, antitussive and anticancer compounds. Several members of a distinct family of S-adenosylmethionine (SAM)-dependent... more
Benzylisoquinoline alkaloids (BIAs) are produced in a wide variety of plants and include many common analgesic, antitussive and anticancer compounds. Several members of a distinct family of S-adenosylmethionine (SAM)-dependent N-methyltransferases (NMTs) play critical roles BIA biosynthesis, but, the molecular basis of substrate recognition and catalysis are not known for NMTs involved in BIA metabolism. To address this issue, the crystal structure of pavine NMT (PavNMT) from Thalictrum flavum was solved using selenomethionine-substituted protein (dmin = 2.8 Å). Additional structures were determined for the native protein (dmin = 2.0 Å), as well as binary complexes with SAM (dmin = 2.3 Å) or the reaction product S-adenosylhomocysteine (SAH) (dmin = 1.6 Å). The structure of a complex with SAH and two molecules of tetrahydropapaverine (THP, one as the S conformer and a second in the R configuration) (dmin = 1.8 Å) revealed key features of substrate recognition. PavNMT converted racemi...
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When overexpressed in Xenopus embryos, Xwnt-1, -3A, -8 and -8b define a functional class of Wnts (the Wnt-1 class) that promotes duplication of the embryonic axis, whereas Xwnt-5A, -4, and -11 define a distinct class (the Wnt-5A class)... more
When overexpressed in Xenopus embryos, Xwnt-1, -3A, -8 and -8b define a functional class of Wnts (the Wnt-1 class) that promotes duplication of the embryonic axis, whereas Xwnt-5A, -4, and -11 define a distinct class (the Wnt-5A class) that alters morphogenetic movements (Du, S., S. Purcell, J. Christian, L. McGrew, and R. Moon. 1995. Mol. Cell. Biol. 15:2625-2634). Since come embryonic cells may be exposed to signals from both functional classes of Wnt during vertebrate development, this raises the question of how the signaling pathways of these classes of Wnts might interact. To address this issue, we coexpressed various Xwnts and components of the Wnt-1 class signaling pathway in developing Xenopus embryos. Members of the Xwnt-5A class antagonized the ability of ectopic Wnt-1 class to induce goosecoid expression and a secondary axis. Interestingly, the Wnt-5A class did not block goosecoid expression or axis induction in response to overexpression of cytoplasmic components of the ...
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Eggs of Xenopus laevis undergo a postfertilization cortical rotation that specifies the position of the dorso-ventral axis and activates a transplantable dorsal-determining activity in dorsal blastomeres by the 32-cell stage. There have... more
Eggs of Xenopus laevis undergo a postfertilization cortical rotation that specifies the position of the dorso-ventral axis and activates a transplantable dorsal-determining activity in dorsal blastomeres by the 32-cell stage. There have heretofore been no reported dorso-ventral asymmetries in endogenous signaling proteins that may be involved in this dorsal-determining activity during early cleavage stages. We focused on β-catenin as a candidate for an asymmetrically localized dorsal-determining factor since it is both necessary and sufficient for dorsal axis formation. We report that β-catenin displays greater cytoplasmic accumulation on the future dorsal side of the Xenopus embryo by the two-cell stage. This asymmetry persists and increases through early cleavage stages, with β-catenin accumulating in dorsal but not ventral nuclei by the 16- to 32cell stages. We then investigated which potential signaling factors and pathways are capable of modulating the steady-state levels of en...
Research Interests: Biology, Cell Biology, Medicine, Signal Transduction, Embryo, and 15 moreBiological Sciences, Wnt Signaling, Animals, Proteins, Glycoproteins, Body Patterning, Transforming Growth Factor Beta, The cell, Embryos, Blastula, Lithium chloride, Ultraviolet Rays, Glycogen Synthase Kinase, Glycogen synthase kinases, and Medical and Health Sciences
Catenins are proteins associated with the cytoplasmic domain of cadherins, a family of transmembrane cell adhesion molecules. The cadherin–catenin adhesion system is involved in morphogenesis during development and in the maintenance of... more
Catenins are proteins associated with the cytoplasmic domain of cadherins, a family of transmembrane cell adhesion molecules. The cadherin–catenin adhesion system is involved in morphogenesis during development and in the maintenance of the integrity of different tissue types. Using a gene trap strategy, we have isolated a mouse mutation for the gene encoding the α-E-catenin. This form of the α-catenin appears frequently coexpressed with E-cadherin in epithelial cell types. The mutation obtained eliminates the carboxyl-terminal third of the protein but nevertheless provokes a complete loss-of-function phenotype. Homozygous mutants show disruption of the trophoblast epithelium (the first differentiated embryonic tissue), and development is consequently blocked at the blastocyst stage. This phenotype parallels the defects observed in E-cadherin mutant embryos. Our results show the requirement of the α-E-catenin carboxy terminus for its function and represent evidence of the role of th...
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Research Interests: Immunology, Computational Biology, Biology, Medicine, Software, and 13 moreMolecular Immunology, Humans, Sequence alignment, Allergens, Immunoglobulin E, Information Storage and Retrieval, S100 protein family, Structure activity Relationship, Epitopes, Physicochemical Properties, Database Search, Structural similarity, and Sequence similarity
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Research Interests: Molecular Biology, Human Embryonic Stem Cells, Biology, Medicine, Gene expression, and 15 moreCell line, Mice, Animals, Embryonic Stem Cell, Gene, Clinical Sciences, Gene Targeting, Large Scale, Nerve Growth Factor, Internal ribosome entry site, Biochemistry and cell biology, ES cell, insertional mutagenesis, Reporter gene, and Cell culture techniques
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Research Interests: Developmental Biology, Flow Cytometry, Biology, Cell Biology, Medicine, and 15 moreCell separation, Hematopoiesis, Biological Sciences, Hematopoietic Stem Cells, Liver, Mice, Animals, Embryonic Stem Cell, Megakaryocytes, Haematopoiesis, Aorta, DNA binding proteins, Hematopoietic Stem Cell, Mesonephros, and Medical and Health Sciences
Research Interests: Developmental Biology, Biology, Cell Biology, Transcription Factors, Morphogenesis, and 14 moreMedicine, Transgenic Mice, Biological Sciences, Spleen, Mice, Animals, Developmental, Embryonic Development, Organ Culture, Transgenic Mouse Technology, Stomach, Reporter gene, Medical and Health Sciences, and mouse embryo
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Research Interests: Genetics, Genomics, Computational Biology, Plant Biology, Biology, and 15 moreMedicine, Functional Genomics, Mutagenesis, Maize, DNA Extraction, Herbicide Resistance, Gene, Arabidopsis, Plant cell, Large Scale, Base Sequence, PLANT PROTEINS, DNA binding proteins, Biochemistry and cell biology, and insertional mutagenesis
Research Interests: Biology, Cell Biology, Apoptosis, Medicine, Arabidopsis thaliana, and 14 moreBiological Sciences, Plant diseases, Mutation, Reactive Oxygen Species, Cell Death, Programmed cell death, Arabidopsis, NADPH oxidase, Superoxide, Hypersensitive Response, Salicylic Acid, PLANT PROTEINS, Respiratory Burst, and Medical and Health Sciences
Pseudomonas syringae strains deliver diverse type III effector proteins into host cells, where they can act as virulence factors. Although the functions of the majority of type III effectors are unknown, several have been shown to... more
Pseudomonas syringae strains deliver diverse type III effector proteins into host cells, where they can act as virulence factors. Although the functions of the majority of type III effectors are unknown, several have been shown to interfere with plant basal defense mechanisms. Type III effectors also could contribute to bacterial virulence by enhancing nutrient uptake and pathogen adaptation to the environment of the host plant. We demonstrate that the type III effector HopAM1 (formerly known as AvrPpiB) enhances the virulence of a weak pathogen in plants that are grown under drought stress. This is the first report of a type III effector that aids pathogen adaptation to water availability in the host plant. Expression of HopAM1 makes transgenic Ws-0 Arabidopsis hypersensitive to abscisic acid (ABA) for stomatal closure and germination arrest. Conditional expression of HopAM1 in Arabidopsis also suppresses basal defenses. ABA responses overlap with defense responses and ABA has been...
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Reactive oxygen intermediates (ROI) are strongly associated with plant defense responses. The origin of these ROI has been controversial. Arabidopsis respiratory burst oxidase homologues ( rboh genes) have been proposed to play a role in... more
Reactive oxygen intermediates (ROI) are strongly associated with plant defense responses. The origin of these ROI has been controversial. Arabidopsis respiratory burst oxidase homologues ( rboh genes) have been proposed to play a role in ROI generation. We analyzed lines carrying dSpm insertions in the highly expressed AtrbohD and AtrbohF genes. Both are required for full ROI production observed during incompatible interactions with the bacterial pathogen Pseudomonas syringae pv. tomato DC3000( avrRpm1 ) and the oomycete parasite Peronospora parasitica . We also observed reduced cell death, visualized by trypan blue stain and reduced electrolyte leakage, in the Atrboh mutants after DC3000( avrRpm1 ) inoculation. However, enhanced cell death is observed after infection of mutant lines with P. parasitica . Paradoxically, although atrbohD mutation eliminated the majority of total ROI production, atrbohF mutation exhibited the strongest effect on cell death.
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The Wilms tumor suppressor gene (Wt1) encodes a C2H2-type zinc-finger transcription factor that participates in transcriptional regulation, RNA metabolism, and protein–protein interactions. WT1 is involved in the development of several... more
The Wilms tumor suppressor gene (Wt1) encodes a C2H2-type zinc-finger transcription factor that participates in transcriptional regulation, RNA metabolism, and protein–protein interactions. WT1 is involved in the development of several organs, including the kidneys and gonads, heart, spleen, adrenal glands, liver, diaphragm, and neuronal system. We previously provided evidence of transient WT1 expression in about 25% of cardiomyocytes of mouse embryos. Conditional deletion of Wt1 in the cardiac troponin T lineage caused abnormal cardiac development. A low expression of WT1 has also been reported in adult cardiomyocytes. Therefore, we aimed to explore its function in cardiac homeostasis and in the response to pharmacologically induced damage. Silencing of Wt1 in cultured neonatal murine cardiomyocytes provoked alterations in mitochondrial membrane potential and changes in the expression of genes related to calcium homeostasis. Ablation of WT1 in adult cardiomyocytes by crossing αMHCM...
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Heart morphogenesis is a complex and dynamic process that has captivated researchers for almost a century. This process involves three main stages, during which the heart undergoes growth and folding on itself to form its common chambered... more
Heart morphogenesis is a complex and dynamic process that has captivated researchers for almost a century. This process involves three main stages, during which the heart undergoes growth and folding on itself to form its common chambered shape. However, imaging heart development presents significant challenges due to the rapid and dynamic changes in heart morphology. Researchers have used different model organisms and developed various imaging techniques to obtain high-resolution images of heart development. Advanced imaging techniques have allowed the integration of multiscale live imaging approaches with genetic labeling, enabling the quantitative analysis of cardiac morphogenesis. Here, we discuss the various imaging techniques used to obtain high-resolution images of whole-heart development. We also review the mathematical approaches used to quantify cardiac morphogenesis from 3D and 3D+time images and to model its dynamics at the tissue and cellular levels.
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Guided ultrasonic waves have many useful properties that can be exploited for non-destructive testing (NDT) and structural health monitoring (SHM) applications. However, for a reliable fault monitoring, much information and an improved... more
Guided ultrasonic waves have many useful properties that can be exploited for non-destructive testing (NDT) and structural health monitoring (SHM) applications. However, for a reliable fault monitoring, much information and an improved understanding of the sources and propagation of these waves is required. The knowledge of characteristics such as attenuation, energy focusing of Lamb waves and wave velocity is then vital for the selection of optimal inspection frequencies, the optimization of sensor networks and a reliable damage localization. On that account, the present paper develops a higher order plate theory for modelling disperse solutions in viscoelastic fibre-reinforced composites in order to investigate the radiation and attenuation of Lamb waves in anisotropic media. Numerical simulations and experiments demonstrate that material anisotropy has a strong influence on the velocities, attenuation and acoustic energy for the different modes of propagation, and that they are f...
Turnip mosaic virus (TuMV) is one of the most important plant viruses worldwide. It has a very wide host range infecting at least 318 species in over 43 families, such as Brassicaceae, Fabaceae, Asteraceae, or Chenopodiaceae from... more
Turnip mosaic virus (TuMV) is one of the most important plant viruses worldwide. It has a very wide host range infecting at least 318 species in over 43 families, such as Brassicaceae, Fabaceae, Asteraceae, or Chenopodiaceae from dicotyledons. Plant NADPH oxidases, the respiratory burst oxidase homologues (RBOHs), are a major source of reactive oxygen species (ROS) during plant–microbe interactions. The functions of RBOHs in different plant–pathogen interactions have been analyzed using knockout mutants, but little focus has been given to plant–virus responses. Therefore, in this work we tested the response after mechanical inoculation with TuMV in ArabidopsisrbohD and rbohF transposon knockout mutants and analyzed ultrastructural changes after TuMV inoculation. The development of the TuMV infection cycle was promoted in rbohD plants, suggesting that RbohD plays a role in the Arabidopsis resistance response to TuMV. rbohF and rbohD/F mutants display less TuMV accumulation and a lack...
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Aliovalent substitutions in Ca3Co4O9 often result in complex effects on the electrical properties and the solubility, and impact of the substituting cation also depends largely on the preparation and processing method. It is also... more
Aliovalent substitutions in Ca3Co4O9 often result in complex effects on the electrical properties and the solubility, and impact of the substituting cation also depends largely on the preparation and processing method. It is also well-known that the monoclinic symmetry of this material’s composite crystal structure allows for a significant hole transfer from the rock salt-type Ca2CoO3 buffer layers to the hexagonal CoO2 ones, increasing the concentration of holes and breaking the electron–hole symmetry from the latter layers. This work explored the relevant effects of relatively low La-for-Ca substitutions, for samples prepared and processed through a conventional ceramic route, chosen for its simplicity. The obtained results show that the actual substitution level does not exceed 0.03 (x < 0.03) in Ca3−xLaxCo4O9 samples with x = 0.01, 0.03, 0.05 and 0.07 and that further introduction of lanthanum results in simultaneous Ca3Co4O9 phase decomposition and secondary Ca3Co2O6 and (La...
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A transcription factor gradient conveys positional information in the vertebrate limb bud.
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ABSTRACTVertebrate axial skeletal patterning is controlled by coordinated collinear expression ofHoxgenes and axial level-dependent activity of Hox protein combinations. Transcription factors of the Meis family act as cofactors of Hox... more
ABSTRACTVertebrate axial skeletal patterning is controlled by coordinated collinear expression ofHoxgenes and axial level-dependent activity of Hox protein combinations. Transcription factors of the Meis family act as cofactors of Hox proteins and profusely bind to Hox complex DNA, however their roles in mammalian axial patterning have not been established. Similarly, retinoic acid (RA) is known to regulate axial skeletal element identity through the transcriptional activity of its receptors, however, whether this role is related to Meis/Hox activity in axial patterning remains unknown. Here we study the role of Meis in axial skeleton formation and its relationship to the RA pathway by characterizingMeis1,Meis2andRaldh2mutant mice. Meis elimination produces axial skeleton defects without affecting Hox gene transcription, including vertebral homeotic transformations and rib mis-patterning associated to defects in the hypaxial myotome. While Raldh2 and Meis positively regulate each ot...
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Abstract A nonlinear strategy for a high voltage direct current power transmission system (HVDC) based on voltage-source-converters is proposed. Specifically, a point-to-point monopole link between two three-phase systems which may... more
Abstract A nonlinear strategy for a high voltage direct current power transmission system (HVDC) based on voltage-source-converters is proposed. Specifically, a point-to-point monopole link between two three-phase systems which may operate at different frequencies is analyzed. Based on the dq model of the open loop system, the expressions which define its operating points are obtained. These expressions allow the analysis of the operating regions of the system. After the open loop analysis, a control strategy is proposed based ...
Research Interests: Engineering, Biology, Control system, Computer Simulation, Power Transmission, and 14 moreReactive Power, Linearization, Control Strategy, Converters, Operating Point, Pulse Width Modulation, Input Output, Ac Power, Voltage Source, Power flow, High Voltage Direct Current, Voltage Source Converter, Power System Simulation, and Voltage Regulation
Research Interests: Biology, Medicine, Gene expression, Environmental Change, Arabidopsis thaliana, and 15 moreBiological Sciences, Mutation, Brassicaceae, New, Alternative splicing, Endosperm, Arabidopsis, Abscisic Acid, NADPH oxidase, Germination, Environmental Conditions, Model System, Alternative Splicing, Dormancy, and Protein carbonylation
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Research Interests: Biology, Calcium, Cell Biology, Medicine, Signal Transduction, and 14 moreBiological Sciences, Mutation, Reactive Oxygen Species, Calcium channels, Stomata, Gene, Arabidopsis, Abscisic Acid, NADPH oxidase, Hydrogen Peroxide, Gene Function, Base Sequence, Medical and Health Sciences, and Protein subunits
Reactive oxygen species restrict cell death at sites of parasitic nematode infection and support nurse cell formation in plant roots.