14 research outputs found
Natural diversity in stomatal features of cultivated and wild Oryza species
Background
Stomata in rice control a number of physiological processes by regulating gas and water exchange between the atmosphere and plant tissues. The impact of the structural diversity of these micropores on its conductance level is an important area to explore before introducing stomatal traits into any breeding program in order to increase photosynthesis and crop yield. Therefore, an intensive measurement of structural components of stomatal complex (SC) of twenty three Oryza species spanning the primary, secondary and tertiary gene pools of rice has been conducted.
Results
Extensive diversity was found in stomatal number and size in different Oryza species and Oryza complexes. Interestingly, the dynamics of stomatal traits in Oryza family varies differently within different Oryza genetic complexes. Example, the Sativa complex exhibits the greatest diversity in stomatal number, while the Officinalis complex is more diverse for its stomatal size. Combining the structural information with the Oryza phylogeny revealed that speciation has tended towards increasing stomatal density rather than stomatal size in rice family. Thus, the most recent species (i.e. the domesticated rice) eventually has developed smaller yet numerous stomata. Along with this, speciation has also resulted in a steady increase in stomatal conductance (anatomical, gmax) in different Oryza species. These two results unambiguously prove that increasing stomatal number (which results in stomatal size reduction) has increased the stomatal conductance in rice. Correlations of structural traits with the anatomical conductance, leaf carbon isotope discrimination (â13C) and major leaf morphological and anatomical traits provide strong supports to untangle the ever mysterious dependencies of these traits in rice. The result displayed an expected negative correlation in the number and size of stomata; and positive correlations among the stomatal length, width and area with guard cell length, width on both abaxial and adaxial leaf surfaces. In addition, gmax is found to be positively correlated with stomatal number and guard cell length. The â13C values of rice species showed a positive correlation with stomatal number, which suggest an increased water loss with increased stomatal number. Interestingly, in contrast, the â13C consistently shows a negative relationship with stomatal and guard cell size, which suggests that the water loss is less when the stomata are larger. Therefore, we hypothesize that increasing stomatal size, instead of numbers, is a better approach for breeding programs in order to minimize the water loss through stomata in rice.
Conclusion
Current paper generates useful data on stomatal profile of wild rice that is hitherto unknown for the rice science community. It has been proved here that the speciation has resulted in an increased stomatal number accompanied by size reduction during Oryzaâs evolutionary course; this has resulted in an increased gmax but reduced water use efficiency. Although may not be the sole driver of water use efficiency in rice, our data suggests that stomata are a potential target for modifying the currently low water use efficiency in domesticated rice. It is proposed that Oryza barthii can be used in traditional breeding programs in enhancing the stomatal size of elite rice cultivars
Description and performance of track and primary-vertex reconstruction with the CMS tracker
A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of pT > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of pT = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in pT, and respectively, 10ÎŒm and 30ÎŒm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10â12ÎŒm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung
Revisiting constraints on asteroid-mass primordial black holes as dark matter candidates
Galaxy Clusters Discovered via the Thermal Sunyaev-Zel'dovich Effect in the 500-square-degree SPTpol Survey
International audienceWe present a catalog of 689 galaxy cluster candidates detected at significance via their thermal Sunyaev-Zel'dovich (SZ) effect signature in 95 and 150 GHz data from the 500-square-degree SPTpol survey. We use optical and infrared data from the Dark Energy Camera and the Wide-field Infrared Survey Explorer (WISE) and \spitzer satellites, to confirm 544 of these candidates as clusters with purity. The sample has an approximately redshift-independent mass threshold at redshift and spans . We use external radio data from the Sydney University Molonglo Sky Survey (SUMSS) to estimate contamination to the SZ signal from synchrotron sources. The contamination reduces the recovered by a median value of 0.032, or of the threshold value, and of candidates have a predicted contamination greater than . With the exception of a small number of systems , an analysis of clusters detected in single-frequency 95 and 150 GHz data shows no significant contamination of the SZ signal by emission from dusty or synchrotron sources. This cluster sample will be a key component in upcoming astrophysical and cosmological analyses of clusters. The SPTpol millimeter-wave maps and associated data products used to produce this sample are available at https://pole.uchicago.edu/public/Data/Releases.html, and the NASA LAMBDA website. An interactive sky server with the SPTpol maps and Dark Energy Survey data release 2 images is also available at NCSA https://skyviewer.ncsa.illinois.edu
Galaxy Clusters Discovered via the Thermal Sunyaev-Zel'dovich Effect in the 500-square-degree SPTpol Survey
International audienceWe present a catalog of 689 galaxy cluster candidates detected at significance via their thermal Sunyaev-Zel'dovich (SZ) effect signature in 95 and 150 GHz data from the 500-square-degree SPTpol survey. We use optical and infrared data from the Dark Energy Camera and the Wide-field Infrared Survey Explorer (WISE) and \spitzer satellites, to confirm 544 of these candidates as clusters with purity. The sample has an approximately redshift-independent mass threshold at redshift and spans . We use external radio data from the Sydney University Molonglo Sky Survey (SUMSS) to estimate contamination to the SZ signal from synchrotron sources. The contamination reduces the recovered by a median value of 0.032, or of the threshold value, and of candidates have a predicted contamination greater than . With the exception of a small number of systems , an analysis of clusters detected in single-frequency 95 and 150 GHz data shows no significant contamination of the SZ signal by emission from dusty or synchrotron sources. This cluster sample will be a key component in upcoming astrophysical and cosmological analyses of clusters. The SPTpol millimeter-wave maps and associated data products used to produce this sample are available at https://pole.uchicago.edu/public/Data/Releases.html, and the NASA LAMBDA website. An interactive sky server with the SPTpol maps and Dark Energy Survey data release 2 images is also available at NCSA https://skyviewer.ncsa.illinois.edu
Galaxy Clusters Discovered via the Thermal Sunyaev-Zel'dovich Effect in the 500-square-degree SPTpol Survey
International audienceWe present a catalog of 689 galaxy cluster candidates detected at significance via their thermal Sunyaev-Zel'dovich (SZ) effect signature in 95 and 150 GHz data from the 500-square-degree SPTpol survey. We use optical and infrared data from the Dark Energy Camera and the Wide-field Infrared Survey Explorer (WISE) and \spitzer satellites, to confirm 544 of these candidates as clusters with purity. The sample has an approximately redshift-independent mass threshold at redshift and spans . We use external radio data from the Sydney University Molonglo Sky Survey (SUMSS) to estimate contamination to the SZ signal from synchrotron sources. The contamination reduces the recovered by a median value of 0.032, or of the threshold value, and of candidates have a predicted contamination greater than . With the exception of a small number of systems , an analysis of clusters detected in single-frequency 95 and 150 GHz data shows no significant contamination of the SZ signal by emission from dusty or synchrotron sources. This cluster sample will be a key component in upcoming astrophysical and cosmological analyses of clusters. The SPTpol millimeter-wave maps and associated data products used to produce this sample are available at https://pole.uchicago.edu/public/Data/Releases.html, and the NASA LAMBDA website. An interactive sky server with the SPTpol maps and Dark Energy Survey data release 2 images is also available at NCSA https://skyviewer.ncsa.illinois.edu
A measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and DES
We infer the mean optical depth of a sample of optically-selected galaxy clusters from the Dark Energy Survey (DES) via the pairwise kinematic Sunyaev-Zel'dovich (kSZ) effect. The pairwise kSZ signal between pairs of clusters drawn from the DES Year-3 cluster catalog is detected at in cosmic microwave background (CMB) temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the deg of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise kSZ signal is , while that inferred from the thermal SZ signal is . The two measures agree at . We perform a suite of systematic checks to test the robustness of the analysis
A measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and DES
We infer the mean optical depth of a sample of optically-selected galaxy clusters from the Dark Energy Survey (DES) via the pairwise kinematic Sunyaev-Zel'dovich (kSZ) effect. The pairwise kSZ signal between pairs of clusters drawn from the DES Year-3 cluster catalog is detected at in cosmic microwave background (CMB) temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the deg of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise kSZ signal is , while that inferred from the thermal SZ signal is . The two measures agree at . We perform a suite of systematic checks to test the robustness of the analysis
A measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and DES
We infer the mean optical depth of a sample of optically-selected galaxy clusters from the Dark Energy Survey (DES) via the pairwise kinematic Sunyaev-Zel'dovich (kSZ) effect. The pairwise kSZ signal between pairs of clusters drawn from the DES Year-3 cluster catalog is detected at in cosmic microwave background (CMB) temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the deg of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise kSZ signal is , while that inferred from the thermal SZ signal is . The two measures agree at . We perform a suite of systematic checks to test the robustness of the analysis