Subsurface bending and reorientation of tilted vortex lattices in bulk isotropic superconductors due to Coulomb-like repulsion at the surface

We study vortex lattices (VLs) in superconducting weak-pinning platelet-like single crystals of β-Bi2Pd in tilted magnetic fields with a scanning tunneling microscope. We show that vortices exit the sample perpendicular to the surface and are thus bent beneath the surface. The structure and orientation of the tilted VLs in the bulk are, for large tilt angles, strongly affected by Coulomb-type intervortex repulsion at the surface due to stray magnetic fieldsThe authors are grateful to P. C. Canfield for discussions, for having proposed the growth of single crystals of β-Bi2 Pd, and for having shown how to do that. E.H. was supported by the Departamento Administrativo de Ciencia, Tecnología e Innovación, COLCIENCIAS (Colombia) Programa Doctorados en el Exterior Convocatoria Program No. 568-2012 and the Universidad Nacional de Colombia, División de Investigación y Extensión sede Bogotá (DIEB) Project No. 35615. I.G. was supported by the ERC (Grant Agreement No. 679080 and the Ramón y Cajal Program through Grant No. RyC-2014-15093). This work also was supported by the Spanish MINECO (Grants No. FIS2014-54498-R and No. MAT2014-52405-C2-02), by the Comunidad de Madrid through Program NANOFRONTMAG-CM (Program No. S2013/MIT-2850), and by Axa Research Funds. We also acknowledge the SEGAINVEX workshop of UAM, Banco Santander and COST Grant No. CA16128 action, the EU through Grant Agreements No. FP7-PEOPLE-2013-CIG 618321 and No. 604391, and Nanopyme Grant No. FP7-NMP-2012-SMALL-6 NMP3-SL 2012-310516. V.G.K. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The Ames Laboratory is operated for the U.S. DOE by Iowa State University under Contract No. DE-AC02-07CH1135

Identification of new sources of resistance to RHBV- rice hoja blanca virus

With the aim to find new sources of resistance to rice hoja blanca (white leaf) disease, transmitted by the insect Tagosodes orizicolus, 660 genotypes were evaluated under greenhouse and field conditions. Seven resistant genotypes were identified, and genomic studies were performed to demonstrate that the resistance in these sources is genetically different from that of Fedearroz 2000, which is currently the variety with the most resistance to hoja blanca. These new resistance sources constitute a resource that can be used to sustainably extend hoja blanca disease management throughout all of the rice-growing regions of tropical America. This is the first report of hoja blanca resistance in indica rice and different from that of Fedearroz 2000.Con el objetivo de encontrar nuevas fuentes de resistencia a la enfermedad de la hoja blanca del arroz, transmitida por el insecto Tagosodes orizicolus, se evaluaron 660 genotipos en condiciones de invernadero y campo. Se identificaron siete genotipos con resistencia a la enfermedad y se realizaron estudios del genoma para evidenciar que eran genéticamente diferentes a Fedearroz 2000, la variedad de mejor comportamiento ante el virus, en el momento. Estas nuevas fuentes de resistencia constituyen un recurso que puede utilizarse para extender un manejo sostenible de la enfermedad, en todas las regiones productoras de arroz en América tropical. Este es el primer reporte de fuentes de resistencia, tipo indica, diferentes a Fedearroz 2000

Efficient photosynthesis in dynamic light environments: a chloroplast's perspective

In nature, light availability for photosynthesis can undergo massive changes on a very short timescale. Photosynthesis in such dynamic light environments requires that plants can respond swiftly. Expanding our knowledge of the rapid responses that underlie dynamic photosynthesis is an important endeavor: It provides insights into nature's design of a highly dynamic energy conversion system and hereby can open up new strategies for improving photosynthesis in the field. The present review focuses on three processes that have previously been identified as promising engineering targets for enhancing crop yield by accelerating dynamic photosynthesis, all three of them involving or being linked to processes in the chloroplast, i.e. relaxation of non-photochemical quenching, Calvin-Benson-Bassham cycle enzyme activation/deactivation and dynamics of stomatal conductance. We dissect these three processes on the functional and molecular level to reveal gaps in our understanding and critically discuss current strategies to improve photosynthesis in the field.</p

Interacciones entre el balance nutricional, los indicadores del metabolismo energético y proteico y las concentraciones plasmáticas de Insulina, e IGF-1 en vacas en lactancia temprana

Con el fin de evaluar la influencia del balance nutricional sobre los indicadores del metabolismo energético y proteico y sobre la generación de insulina y del factor 1 insulinoide de crecimiento (IGF-1), se utilizaron 10 vacas Holstein, las cuales se muestrearon el día 12 preparto y los días 12, 24, 35 y 100 posparto (días en lactancia, DEL) para determinar los balance de energía neta de lactancia (ENL), proteína cruda (PC), proteína degradable en rumen (PDR) y proteína no degradable en rumen (PNDR), así como los cambios de peso. Adicionalmente se determinaron las concentraciones plasmáticas de urea (BUN), glucosa, colesterol total, amonio, ß-OH butirato, ácidos grasos no esterificados (AGNE), insulina, IGF-1 y la actividad glutamato oxaloacetato transaminasa (AST). ENL y PC fueron positivos para el muestreo preparto. En el día 12 posparto ENL y PC fueron negativos, al día 35 posparto los valores de PC fueron cero o superiores mientras que para ENL solo se observaron valores positivos al día 100 posparto. Los DEL se relacionaron positivamente con ENL y PC. La producción de leche se relacionó negativamente con ENL, PC, PDR, PNDR. Los valores de glicemia e IGF-1 fueron significativamente más bajos en el posparto. Los valores promedio de cambio de peso, ß-OH butirato, BUN, amonio e insulina plasmáticos no presentaron variaciones significativas entre periodos. Los valores de AST fueron significativamente más bajos en el preparto que en el posparto. Los valores más bajos de AGNE correspondieron en su orden al muestreo correspondiente al día 100 posparto y al muestreo preparto, coincidiendo con balances energéticos positivos. Se encontraron relaciones positivas entre colesterol y DEL, ENL, PC, PDR, PNDR; entre colesterol y glicemia; entre BUN y colesterol; entre glicemia y DEL. Se encontraron relaciones negativas entre la producción de leche y la insulina plasmática; entre ENL y AGNE; entre BUN y AST

Sparse representations of dynamic scenes for compressive spectral video sensing

The coded aperture snapshot spectral imager (CASSI) is an optical architecture that captures spectral images using compressive sensing. This system improves the sensing speed and reduces the large amount of collected data given by conventional spectral imaging systems. In several applications, it is necessary to analyze changes that occur between short periods of time. This paper first presents a sparsity analysis for spectral video signals, to obtain accurate approximations and better comply compressed sensing theory. The use of the CASSI system in compressive spectral video sensing then is proposed. The main goal of this approach is to capture the spatio-spectral information of dynamic scenes using a 2-dimensional set of projections. This application involves the use of a digital micro-mirror device that implements the traditional coded apertures used by CASSI. Simulations show that accurate reconstructions along the spatial, spectral and temporal axes are attained, with PSNR values of around 30 dB.El sistema de adquisición de imágenes espectrales de apertura codificada (CASSI) es una arquitectura óptica que capta imágenes espectrales usando muestreo compresivo. Este sistema acelera la detección y reduce la gran cantidad de datos adquiridos por los sistemas tradicionales. En algunas aplicaciones es necesario analizar la variabilidad de la escena en períodos cortos de tiempo. Este trabajo presenta un análisis de las bases de representación para imágenes espectrales dinámicas, con el fin de obtener aproximaciones correctas a partir de su representación dispersa, y permitir la aplicación de muestreo compresivo. Posteriormente se propone el uso del sistema CASSI captar la información espacial y espectral de escenas dinámicas utilizando un conjunto de proyecciones bidimensionales. Esto implica el uso de un dispositivo de microespejos digitales que implementa las aperturas codificadas utilizadas en CASSI. Resultados muestran que es posible obtener reconstrucciones correctas en las dimensiones espaciales, espectral y temporal, con valores de PSNR alrededor de 30 dB

Influencia de las alteraciones metabólicas sobre la actividad PEPCK, la generación de IGF-1 plasmático y la reactivación ovárica en vacas en la lactancia temprana

Con el fin de evaluar la influencia de las alteraciones en el metabolismo energético y proteico sobre la actividad de la enzima fosfoenolpiruvato carboxikinasa (PEPCK), la generación de insulina, del factor 1 insulinoide de crecimiento (IGF-1) y sobre la reactivación ovárica, se utilizaron 10 vacas Holstein, las cuales se muestrearon el día 12 preparto y los días 12, 24, 35 y 100 posparto (días en lactancia, DEL) con el fin de determinar el balance de energía neta de lactancia (ENL), las concentraciones plasmáticas de urea (BUN), glucosa, colesterol total, amonio, b-OH butirato, ácidos grasos no esterificados (AGNE), insulina, IGF-1 y la actividad glutamato oxaloacetato transaminasa (AST). Adicionalmente los días 12, 16, 20, 24, 28, 32, 36 y 40 posparto se determinó la concentración de progesterona plasmática (p4). El día 12 preparto, 12 y 24 posparto se tomaron biopsias de hígado con el objetivo de estimar la actividad (PEPCK). Los valores de glicemia e IGF-1 fueron significativamente más bajos en el posparto. Los valores promedio de b-OH butirato, BUN, amonio e insulina plasmáticos no presentaron variaciones significativas entre periodos. Los valores de AST fueron significativamente más bajos en el preparto que en el posparto. Los valores más bajos de AGNE correspondieron en su orden al muestreo corres-pondiente al día 100 posparto y al muestreo preparto. La actividad PEPCK fue significativamente más alta en el preparto que en el posparto. Se encontraron relaciones positivas entre PEPCK y BUN, y entre ENL y p4. Se encontraron relaciones negativas entre PEPCK y ß-OH butirato y entre AGNE y p4. La relación entre PEPCK e IGF-1 y entre AGNE y p4 pudo ser debida a un efecto indirecto de la glicemia y de ENL. Solo las vacas con ENL superior a -10% de los requerimientos presentaron reactivación ovárica

Plant and Cell Physiology

Crop canopies create environments of highly fluctuating light intensities. In such environments, photoprotective mechanisms and their relaxation kinetics have been hypothesized to limit photosynthetic efficiency and therefore crop yield potential. Here, we show that overexpression of the Arabidopsis thylakoid K(+)/H(+) antiporter KEA3 accelerates the relaxation of photoprotective energy-dependent quenching after transitions from high to low light in Arabidopsis and tobacco. This, in turn, enhances PSII quantum efficiency in both organisms, supporting that in wild-type plants, residual light energy quenching following a high to low light transition represents a limitation to photosynthetic efficiency in fluctuating light. This finding underscores the potential of accelerating quenching relaxation as a building block for improving photosynthetic efficiency in the field. Additionally, by overexpressing natural KEA3 variants with modification to the C-terminus, we show that KEA3 activity is regulated by a mechanism involving its lumen-localized C-terminus, which lowers KEA3 activity in high light. This regulatory mechanism fine-tunes the balance between photoprotective energy dissipation in high light and maximum quantum yield in low light, likely to be critical for efficient photosynthesis in fluctuating light conditions

Subsurface bending and reorientation of tilted vortex lattices in bulk isotropic superconductors due to Coulomb-like repulsion at the surface

We study vortex lattices (VLs) in superconducting weak-pinning platelet-like single crystals of β-Bi2Pd in tilted magnetic fields with a scanning tunneling microscope. We show that vortices exit the sample perpendicular to the surface and are thus bent beneath the surface. The structure and orientation of the tilted VLs in the bulk are, for large tilt angles, strongly affected by Coulomb-type intervortex repulsion at the surface due to stray magnetic fields.E.H. was supported by the Departamento Administrativo de Ciencia, Tecnología e Innovación, COLCIENCIAS (Colombia) Programa Doctorados en el Exterior Convocatoria Program No. 568-2012 and the Universidad Nacional de Colombia, División de Investigación y Extensión sede Bogotá (DIEB) Project No. 35615. I.G. was supported by the ERC (Grant Agreement No. 679080 and the Ramón y Cajal Program through Grant No. RyC-2014-15093). This work also was supported by the Spanish MINECO (Grants No. FIS2014-54498-R and No. MAT2014-52405-C2-02), by the Comunidad de Madrid through Program NANOFRONTMAG-CM (Program No. S2013/MIT-2850), and by Axa Research Funds. We also acknowledge the SEGAINVEX workshop of UAM, Banco Santander and COST Grant No. CA16128 action, the EU through Grant Agreements No. FP7-PEOPLE-2013-CIG 618321 and No. 604391, and Nanopyme Grant No. FP7-NMP-2012-SMALL-6 NMP3-SL 2012-310516. V.G.K. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The Ames Laboratory is operated for the U.S. DOE by Iowa State University under Contract No. DE-AC02-07CH11358

Stromal NADH supplied by PHOSPHOGLYCERATE DEHYDROGENASE3 is crucial for photosynthetic performance

During photosynthesis, electrons travel from light-excited chlorophyll molecules along the electron transport chain to the final electron acceptor NADP to form NADPH, which fuels the Calvin–Benson–Bassham Cycle (CBBC). To allow photosynthetic reactions to occur flawlessly, a constant resupply of the acceptor NADP is mandatory. Several known stromal mechanisms aid in balancing the redox poise, but none of them utilizes the structurally highly similar coenzyme NAD(H). Using Arabidopsis (Arabidopsis thaliana) as a C3-model, we describe a pathway that employs the stromal enzyme PHOSPHOGLYCERATE DEHYDROGENASE 3 (PGDH3). We showed that PGDH3 exerts high NAD(H)-specificity and is active in photosynthesizing chloroplasts. PGDH3 withdrew its substrate 3-PGA directly from the CBBC. As a result, electrons diverted from NADPH via the CBBC into the separate NADH redox pool. pgdh3 loss-of-function mutants revealed an over-reduced NADP(H) redox pool but a more oxidized plastid NAD(H) pool compared to wild-type plants. As a result, photosystem I acceptor side limitation increased in pgdh3. Furthermore, pgdh3 plants displayed delayed CBBC activation, changes in non-photochemical quenching, and altered proton motive force partitioning. Our fluctuating light-stress phenotyping data showed progressing photosystem II damage in pgdh3 mutants, emphasizing the significance of PGDH3 for plant performance under natural light environments. In summary, this study reveals an NAD(H)-specific mechanism in the stroma that aid in balancing the chloroplast redox poise. Consequently, the stromal NAD(H) pool may provide a promising target to manipulate plant photosynthesis