Photosynthetic O2 Evolution In Maize Inbreds And Their Hybrids Can Be Differentiated By Open Photoacoustic Cell Technique

Photosynthetic efficiency is considered one of the traits potentially suitable to differentiate hybrids from their inbred lines. Previous evaluations concerning photosynthetic efficiencies of maize (Zea mays L.) plants in the field have shown inconsistent and contradictory data. In this work, we attempted to study photosynthetic O2 evolution through photoacoustic spectroscopy in intact undetached leaves of dark-adapted seedlings of inbreds and their hybrids. The results indicate that photosynthetic efficiencies of inbreds and hybrids can be differentiated by photoacoustic measurements of oxygen evolution, providing a parameter that might prove useful in evaluating plant genotypes. © 1995.1042177181Shull, A pure-line method in corn breeding (1909) Am. Breeders Assoc. Rep., 5, pp. 51-59Duvick, Genetic contribution to the yield gains of U.S. hybrid maize, 1930 to 1980 (1984) Genetic Contributions to Yield gains of Five Major Crop Plants, 7, pp. 15-47. , 2nd Edn., W.R. Fehr, Crop Science Society of America Special PublicationRussell, Contribution of breeding to maize improvement in the United States (1986) Iowa State J. Res., 61, pp. 5-34Smith, Smith, Measurement of genetic diversity among maize hybrids: a comparison of isozymic, RFLP, pedigree, and heterosis data (1992) Maydica, 37, pp. 53-60Stuber, Lincoln, Wolff, Helentjaris, Lander, Identification of genetic factors contributing to heterosis in a hybrid from two elite maize inbred lines using molecular markers (1992) Genetics, 132, pp. 823-839Moss, Photosynthesis the corn plant a converter (1960) Proceedings of the 15th Annual Hybrid Corn Industry — Research Conference Publication, 15, pp. 54-60. , 2nd EdnElmore, Hesketh, Muramoto, A survey of rates of leaf growth leaf aging and photosynthetic rates among and within species (1967) Journal of the Arizona Academy of Science, 4, pp. 215-219Heichel, Musgrave, Varietal differences in net photosynthesis of Zea mays L (1969) Crop Science, 9, pp. 483-496Marquezini, Cella, Mansanares, Vargas, Miranda, Open photoacoustic cell spectroscopy (1991) Meas. Sci. Technol., 2, pp. 396-401Pereira, Zerbetto, Silva, Vargas, da Silva, Neto, Cella, Miranda, OPC technique for in vivo studies in plant photosynthesis research (1992) Meas. Sci. Technol., 3, pp. 931-934Pereira, Prioli, da Silva, Neto, Vargas, Cella, Alvarado-Gil, In vivo and in situ measurements of spectroscopic and photosynthetic properties of undetached maize leaves using the open photoacoustic cell technique (1994) Plant Sci., 96, pp. 203-209Poulet, Cahen, Malkin, Photoacoustic detection of photosynthetic oxygen evolution from leaves. Quantitative analysis by phase and amplitude measurements (1983) Biochim. Biophys. Acta, 724, pp. 433-446Walker, Photosynthetic induction phenomena and the light activation of ribulose diphosphate carboxylase (1973) New Phytologist, 72, pp. 209-23

Ciclo anual de precipitação como função de índices de instabilidade termodinâmica e fluxos de energia estática: análises em Maxaranguape-RN Annual rainfall cycle as a function of thermodynamic instability indexes, and static energy fluxes: analysis in Maxaranguape-RN

Estudaram-se índices de instabilidade termodinâmica, conteúdo de água precipitável e fluxos de energia estática associados ao ciclo anual de precipitação sobre Maxaranguape, situada no litoral do Rio Grande do Norte. O período de coleta de dados através de radiossondagens foi de janeiro de 2002 a dezembro de 2009 no âmbito do projeto South Hemisphere ADditional OZonesondes (SHADOZ). Os índices termodinâmicos não explicam o máximo de precipitação observado em julho, porém apresentam-se em fase com um máximo secundário em abril. Os fluxos de energia estática úmida e saturada mostram que o ciclo anual da precipitação é modulado pelos mecanismos que geram instabilidade termodinâmica associados à convergência de umidade em baixos níveis.<br>The relation between thermodynamic instability indexes, precipitable water content, static energy flux, and rainfall annual cycle over Maxaranguape (coastland site, Rio Grande do Norte, Northeast of Brazil) was investigated. The radiosonde dataset covered the period from January 2002 to December 2009 within the South Hemisphere ADditional OZonesondes (SHADOZ) project. The thermodynamics indexes variability do not explain the maximum rainfall in July, however they are in phase with the secondary maximum in April. The annual cycle of the moist and saturated static energy fluxes showed that rainfall cycle is modulated by both thermodynamics and low level moisture convergence mechanisms

Euclid: Early Release Observations -- A preview of the Euclid era through a galaxy cluster magnifying lens

International audienceWe present the first analysis of the Euclid Early Release Observations (ERO) program that targets fields around two lensing clusters, Abell 2390 and Abell 2764. We use VIS and NISP imaging to produce photometric catalogs for a total of $\sim 500\,000$ objects. The imaging data reach a $5\,\sigma$ typical depth in the range 25.1-25.4 AB in the NISP bands, and 27.1-27.3 AB in the VIS band. Using the Lyman-break method in combination with photometric redshifts, we identify $30$ Lyman-break galaxy (LBG) candidates at $z>6$ and 139 extremely red sources (ERSs), most likely at lower redshift. The deeper VIS imaging compared to NISP means we can routinely identify high-redshift Lyman breaks of the order of $3$ magnitudes, which reduces contamination by brown dwarf stars and low-redshift galaxies. Spectroscopic follow-up campaigns of such bright sources will help constrain both the bright end of the ultraviolet galaxy luminosity function and the quasar luminosity function at $z>6$, and constrain the physical nature of these objects. Additionally, we have performed a combined strong lensing and weak lensing analysis of A2390, and demonstrate how Euclid will contribute to better constraining the virial mass of galaxy clusters. From these data, we also identify optical and near-infrared counterparts of known $z>0.6$ clusters, which exhibit strong lensing features, establishing the ability of Euclid to characterize high-redshift clusters. Finally, we provide a glimpse of Euclid's ability to map the intracluster light out to larger radii than current facilities, enabling a better understanding of the cluster assembly history and mapping of the dark matter distribution. This initial dataset illustrates the diverse spectrum of legacy science that will be enabled by the Euclid survey

Euclid: Early Release Observations -- A preview of the Euclid era through a galaxy cluster magnifying lens

International audienceWe present the first analysis of the Euclid Early Release Observations (ERO) program that targets fields around two lensing clusters, Abell 2390 and Abell 2764. We use VIS and NISP imaging to produce photometric catalogs for a total of $\sim 500\,000$ objects. The imaging data reach a $5\,\sigma$ typical depth in the range 25.1-25.4 AB in the NISP bands, and 27.1-27.3 AB in the VIS band. Using the Lyman-break method in combination with photometric redshifts, we identify $30$ Lyman-break galaxy (LBG) candidates at $z>6$ and 139 extremely red sources (ERSs), most likely at lower redshift. The deeper VIS imaging compared to NISP means we can routinely identify high-redshift Lyman breaks of the order of $3$ magnitudes, which reduces contamination by brown dwarf stars and low-redshift galaxies. Spectroscopic follow-up campaigns of such bright sources will help constrain both the bright end of the ultraviolet galaxy luminosity function and the quasar luminosity function at $z>6$, and constrain the physical nature of these objects. Additionally, we have performed a combined strong lensing and weak lensing analysis of A2390, and demonstrate how Euclid will contribute to better constraining the virial mass of galaxy clusters. From these data, we also identify optical and near-infrared counterparts of known $z>0.6$ clusters, which exhibit strong lensing features, establishing the ability of Euclid to characterize high-redshift clusters. Finally, we provide a glimpse of Euclid's ability to map the intracluster light out to larger radii than current facilities, enabling a better understanding of the cluster assembly history and mapping of the dark matter distribution. This initial dataset illustrates the diverse spectrum of legacy science that will be enabled by the Euclid survey

Euclid. I. Overview of the Euclid mission

International audienceThe current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. Euclid is a medium-class mission in the Cosmic Vision 2015-2025 programme of the European Space Agency (ESA) that will provide high-resolution optical imaging, as well as near-infrared imaging and spectroscopy, over about 14,000 deg^2 of extragalactic sky. In addition to accurate weak lensing and clustering measurements that probe structure formation over half of the age of the Universe, its primary probes for cosmology, these exquisite data will enable a wide range of science. This paper provides a high-level overview of the mission, summarising the survey characteristics, the various data-processing steps, and data products. We also highlight the main science objectives and expected performance