Molecular Mapping of a Male-Sterile Gene in Soybean

A newly identified genie male-sterile mutant in soybean [Glycine max (L.) Merr.] has high seed set under natural field conditions and is potentially useful in breeding programs. Meiosis is normal in the mutant line. Sterility in this mutant is caused by failure of cailose dissolution at the tetrad stage, which results in microspore abortion; however, little is known about the male-sterile gene at the molecular level. The objective of this study was to identify molecular markers linked with the male-sterile gene (ms) and to place the ms gene onto the soybean molecular genetic map. An F2 population of 107 individuals was constructed from a cross between the mutant msMOS (ms ms) and the cultivar Minsoy (Ms Ms). Two hundred seventy markers, including 219 RFLP and 51 SSRs, were evaluated. Of these, 102 RFLP probes and 31 SSR markers detected polymorphisms between the parents. The F2 population was screened for segregation of these polymorphic molecular markers. Analyses revealed that the male-sterile locus, designated ‘ms’, was located on linkage group D1b of the USDA/ISU soybean molecular genetic map. The availability of linked DNA markers will facilitate the genetic analysis of this male-sterility gene in relation to soybean breeding programs, and will be a starting point for the isolation of the ms gene by map-based cloning

Fr1 (root fluorescence) locus is located in a segregation distortion region on linkage group K of soybean genetic map

We report the use of bulked segregant SSR analysis for rapid identification of DNA markers linked to the Fr1 locus in soybean. Pooled DNA extracts from 10 homozygous Fr1 Fr1 and 10 fr1 fr1 F2 plants, derived from a msMOS x Minsoy cross, were analyzed using 65 SSR markers. Five SSRs produced repeatable polymorphisms between paired bulks. Linkage with the Fr1 locus was tested using these five SSR primers and DNA from individual plants of each bulk. DNA polymorphisms generated by these five primers were linked to the Fr1 locus. Linkage of SSR loci with the Fr1locus was verified by using an F2 population segregating for Fr1. The five SSR markers and Fr1 are on linkage group K of the USDA ARS/ISU molecular genetic map. The markers flanking Fr1 are Satt337 (11.0 cM) and Satt044 (0.6 cM). Fr1 previously was mapped on linkage group 12 of the classical genetic map. Thus classical genetic linkage group 12 has been correlated to linkage group K of the molecular genetic map. Six SSR markers were chosen on linkage group K to test the segregation ratio. All six SSRs tested were skewed toward the Minsoy genotype, one chi-square value was statistically significant. This suggested that a gametophyte factor may lie in the region close to Fr1 and most likely close to Satt046

Barium-isotopic fractionation in seawater mediated by barite cycling and oceanic circulation

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters, 430 (2015): 511-522, doi:10.1016/j.epsl.2015.07.027.The marine biogeochemical cycle of Ba is thought to be controlled by particulate BaSO4 (barite) precipitation associated with the microbial oxidation of organic carbon and its subsequent dissolution in the BaSO4-undersaturated water column. Despite many of these processes being largely unique to Ba cycling, concentrations of Ba and Si in seawater exhibit a strong linear correlation. The reasons for this correlation are ambiguous, as are the depth ranges corresponding to the most active BaSO4 cycling and the intermediate sources of Ba to particulate BaSO4. Stable isotopic analyses of dissolved Ba in seawater should help address these issues, as Ba-isotopic compositions are predicted to be sensitive to the physical and biogeochemical process that cycle Ba. We report a new methodology for the determination of dissolved Ba-isotopic compositions in seawater and results from a 4, 500 m depth profile in the South Atlantic at 39.99 S, 0.92 E that exhibit oceanographically-consistent variation with depth. These data reveal that water masses obtain their [Ba] and Ba-isotopic signatures when at or near the surface, which relates to the cycling of marine BaSO4. The shallow origin of these signatures requires that the substantial Ba-isotopic variations in the bathypelagic zone were inherited from when those deep waters were last ventilated. Indeed, the water column below 600 m is well explained by conservative mixing of water masses with distinct [Ba] and Ba-isotopic compositions. This leads us to conclude that large scale oceanic circulation is important for sustaining the similar oceanographic distributions of Ba and Si in the South Atlantic, and possibly elsewhere. These data demonstrate that the processes of organic carbon oxidation, BaSO4 cycling, and Ba-isotopic fractionation in seawater are closely coupled, such that Ba-isotopic analyses harbor great potential as a tracer of the carbon cycle in the modern and paleo-oceans.T.J.H. acknowledges support from Makoto A. Saito (Gordon and Betty Moore Foundation; Project # 3782) and the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Doherty Foundation. Development of Ba-isotopic protocols at NIRVANA was made possible with funding from The Andrew W. Mellon Foundation Endowed Fund for Innovative Research (T.J.H. and S.G.N.)

The WARPS survey - IV: The X-ray luminosity-temperature relation of high redshift galaxy clusters

We present a measurement of the cluster X-ray luminosity-temperature relation out to high redshift (z~0.8). Combined ROSAT PSPC spectra of 91 galaxy clusters detected in the Wide Angle ROSAT Pointed Survey (WARPS) are simultaneously fit in redshift and luminosity bins. The resulting temperature and luminosity measurements of these bins, which occupy a region of the high redshift L-T relation not previously sampled, are compared to existing measurements at low redshift in order to constrain the evolution of the L-T relation. We find a best fit to low redshift (z1 keV, to be L proportional to T^(3.15\pm0.06). Our data are consistent with no evolution in the normalisation of the L-T relation up to z~0.8. Combining our results with ASCA measurements taken from the literature, we find eta=0.19\pm0.38 (for Omega_0=1, with 1 sigma errors) where L_Bol is proportional to (1 + z)^eta T^3.15, or eta=0.60\pm0.38 for Omega_0=0.3. This lack of evolution is considered in terms of the entropy-driven evolution of clusters. Further implications for cosmological constraints are also discussed.Comment: 11 pages, 7 figures, accepted for publication in MNRA

InP/Ga0.47In0.53As monolithic, two-junction, three-terminal tandem solar cells

The work presented has focussed on increasing the efficiency of InP-based solar cells through the development of a high-performance InP/Ga(0.47)In(0.53)As two-junction, three-terminal monolithic tandem cell. Such a tandem is particularly suited to space applications where a radiation-hard top cell (i.e., InP) is required. Furthermore, the InP/Ga(0.47)In(0.53)As materials system is lattice matched and offers a top cell/bottom cell bandgap differential (0.60 eV at 300 K) suitable for high tandem cell efficiencies under AMO illumination. A three-terminal configuration was chosen since it allows for independent power collection from each subcell in the monolithic stack, thus minimizing the adverse impact of radiation damage on the overall tandem efficiency. Realistic computer modeling calculations predict an efficiency boost of 7 to 11 percent from the Ga(0.47)In(0.53)As bottom cell under AMO illumination (25 C) for concentration ratios in the 1 to 1000 range. Thus, practical AMO efficiencies of 25 to 32 percent appear possible with the InP/Ga(0.47)In(0.53)As tandem cell. Prototype n/p/n InP/Ga(0.47)In(0.53)As monolithic tandem cells were fabricated and tested successfully. Using an aperture to define the illuminated areas, efficiency measurements performed on a non-optimized device under standard global illumination conditions (25 C) with no antireflection coating (ARC) give 12.2 percent for the InP top cell and 3.2 percent for the Ga(0.47)In(0.53)As bottom cell, yielding an overall tandem efficiency of 15.4 percent. With an ARC, the tandem efficiency could reach approximately 22 percent global and approximately 20 percent AMO. Additional details regarding the performance of individual InP and Ga(0.47)In(0.53)As component cells, fabrication and operation of complete tandem cells and methods for improving the tandem cell performance, are also discussed

Structural dynamics analysis

Dynamic analysis of large space antenna systems must treat the deployment as well as vibration and control of the deployed antenna. Candidate computer programs for deployment dynamics, and issues and needs for future program developments are reviewed. Some results for mast and hoop deployment are also presented. Modeling of complex antenna geometry with conventional finite element methods and with repetitive exact elements is considered. Analytical comparisons with experimental results for a 15 meter hoop/column antenna revealed the importance of accurate structural properties including nonlinear joints. Slackening of cables in this antenna is also a consideration. The technology of designing actively damped structures through analytical optimization is discussed and results are presented

Absorbing systematic effects to obtain a better background model in a search for new physics

This paper presents a novel approach to estimate the Standard Model backgrounds based on modifying Monte Carlo predictions within their systematic uncertainties. The improved background model is obtained by altering the original predictions with successively more complex correction functions in signal-free control selections. Statistical tests indicate when sufficient compatibility with data is reached. In this way, systematic effects are absorbed into the new background model. The same correction is then applied on the Monte Carlo prediction in the signal region. Comparing this method to other background estimation techniques shows improvements with respect to statistical and systematical uncertainties. The proposed method can also be applied in other fields beyond high energy physics

Insect-mediated cross-pollination in soybean [Glycine max (L.) Merrill] : I. Agronomic performance

In soybean, manual cross-pollination to produce large quantities of F1 hybrid seed for yield trials is difficult and time-consuming. Conversely, insect-mediated cross-pollination has been shown to produce large quantities of hybrid seed in soybean and could facilitate the identification of heterotic patterns. The objective of our study was: (1) evaluate F1hybrid soybean plants from single crosses for yield and agronomic traits over several environments and (2) compare hybrid performance of the single crosses to lines developed from three-way crosses and backcrosses. In 2003, F1 seed of single-crosses and their parent lines were evaluated in replicated experiments at three locations. Also in 2003, three-way crosses, and BC1F1 seed were produced. In 2004, three-way crosses, BC1F1 crosses, and their parent lines were evaluated at one location. High-parent heterosis (HPH) in single-crosses for grain yield ranged from −41.11% to +11.19%; for protein content from −4.34% to +3.53%, and for oil content from −13.22% to −0.84%. In three-way crosses, HPH for yield ranged from −25.21% to −4.50%, for protein from −2.72% to +1.92%, and for oil from −5.87% to −1.20%. For BC1F1 crosses, HPH for yield ranged from −15.65% to +41.97%, for protein from −2.57% to +1.69%, and for oil from −2.47% to +2.22%. Although positive heterosis levels were observed across all populations tested to determine the economic feasibility it is imperative that more tests of more cross-combinations be evaluated in replicated environments. Extensive research in different environments must be conducted to determine what parental combinations will produce the highest heterosis levels, and to develop criteria for selecting the parents with the best combining ability. This will be important to maximize agronomic performance that can economically justify the use of hybrids in soybean production

Individual differences in the shape of the nasal visual field

AbstractBetween-subject differences in the shape of the nasal visual field were assessed for 103 volunteers 21–85years of age and free of visual disorder. Perimetry was conducted with a stimulus for which contrast sensitivity is minimally affected by peripheral defocus and decreased retinal illumination. One eye each was tested for 103 volunteers free of eye disease in a multi-center prospective longitudinal study. A peripheral deviation index was computed as the difference in log contrast sensitivity at outer (25–29° nasal) and inner (8° from fixation) locations. Values for this index ranged from 0.01 (outer sensitivity slightly greater than inner sensitivity) to −0.7 log unit (outer sensitivity much lower than inner sensitivity). Mean sensitivity for the inner locations was independent of the deviation index (R2<1%), while mean sensitivity for the outer locations was not (R2=38%, p<0.0005). Age was only modestly related to the index, with a decline by 0.017 log unit per decade (R2=10%). Test-retest data for 21 volunteers who completed 7–10 visits yielded standard deviations for the index from 0.04 to 0.17 log unit, with a mean of 0.09 log unit. Between-subject differences in peripheral deviation persisted over two years of longitudinal testing. Peripheral deviation indices were correlated with indices for three other perimetric stimuli used in a subset of 24 volunteers (R2 from 20% to 49%). Between-subject variability in shape of the visual field raises concerns about current clinical visual field indices, and further studies are needed to develop improved indices

Nature versus Nurture: The curved spine of the galaxy cluster X-ray luminosity -- temperature relation

The physical processes that define the spine of the galaxy cluster X-ray luminosity -- temperature (L-T) relation are investigated using a large hydrodynamical simulation of the Universe. This simulation models the same volume and phases as the Millennium Simulation and has a linear extent of 500 h^{-1} Mpc. We demonstrate that mergers typically boost a cluster along but also slightly below the L-T relation. Due to this boost we expect that all of the very brightest clusters will be near the peak of a merger. Objects from near the top of the L-T relation tend to have assembled much of their mass earlier than an average halo of similar final mass. Conversely, objects from the bottom of the relation are often experiencing an ongoing or recent merger.Comment: 8 pages, 7 figures, submitted to MNRA