1,004 research outputs found
An evaluation of genotyping by sequencing (GBS) to map the <em>Breviaristatum-e (ari-e)</em> locus in cultivated barley
ABSTRACT: We explored the use of genotyping by sequencing (GBS) on a recombinant inbred line population (GPMx) derived from a cross between the two-rowed barley cultivar ‘Golden Promise’ (ari-e.GP/Vrs1) and the six-rowed cultivar ‘Morex’ (Ari-e/vrs1) to map plant height. We identified three Quantitative Trait Loci (QTL), the first in a region encompassing the spike architecture gene Vrs1 on chromosome 2H, the second in an uncharacterised centromeric region on chromosome 3H, and the third in a region of chromosome 5H coinciding with the previously described dwarfing gene Breviaristatum-e (Ari-e). BACKGROUND: Barley cultivars in North-western Europe largely contain either of two dwarfing genes; Denso on chromosome 3H, a presumed ortholog of the rice green revolution gene OsSd1, or Breviaristatum-e (ari-e) on chromosome 5H. A recessive mutant allele of the latter gene, ari-e.GP, was introduced into cultivation via the cv. ‘Golden Promise’ that was a favourite of the Scottish malt whisky industry for many years and is still used in agriculture today. RESULTS: Using GBS mapping data and phenotypic measurements we show that ari-e.GP maps to a small genetic interval on chromosome 5H and that alternative alleles at a region encompassing Vrs1 on 2H along with a region on chromosome 3H also influence plant height. The location of Ari-e is supported by analysis of near-isogenic lines containing different ari-e alleles. We explored use of the GBS to populate the region with sequence contigs from the recently released physically and genetically integrated barley genome sequence assembly as a step towards Ari-e gene identification. CONCLUSIONS: GBS was an effective and relatively low-cost approach to rapidly construct a genetic map of the GPMx population that was suitable for genetic analysis of row type and height traits, allowing us to precisely position ari-e.GP on chromosome 5H. Mapping resolution was lower than we anticipated. We found the GBS data more complex to analyse than other data types but it did directly provide linked SNP markers for subsequent higher resolution genetic analysis
1/N_c Expansion of the Heavy Baryon Isgur-Wise Functions
The 1/N_c expansion of the heavy baryon Isgur-Wise functions is discussed.
Because of the contracted SU(2N_f) light quark spin-flavor symmetry, the
universality relations among the Isgur-Wise functions of \Lambda_b to \Lambda_c
and \Sigma_b^{(*)} to \Sigma_c^{(*)} are valid up to the order of 1/N_c^2.Comment: 7 pages, latex, no figures, to appear in Phys. Rev.
Evolution of brown carbon in wildfire plumes
Particulate brown carbon (BrC) in the atmosphere absorbs light at subvisible wavelengths and has poorly constrained but potentially large climate forcing impacts. BrC from biomass burning has virtually unknown lifecycle and atmospheric stability. Here, BrC emitted from intense wildfires was measured in plumes transported over 2 days from two main fires, during the 2013 NASA SEAC4RS mission. Concurrent measurements of organic aerosol (OA) and black carbon (BC) mass concentration, BC coating thickness, absorption Ångström exponent, and OA oxidation state reveal that the initial BrC emitted from the fires was largely unstable. Using back trajectories to estimate the transport time indicates that BrC aerosol light absorption decayed in the plumes with a half-life of 9 to 15 h, measured over day and night. Although most BrC was lost within a day, possibly through chemical loss and/or evaporation, the remaining persistent fraction likely determines the background BrC levels most relevant for climate forcing
Serum squamous cell carcinoma antigen as an early indicator of response during therapy of cervical cancer
1/m_Q Corrections to the Heavy-to-Light-Vector Transitions in the HQET
Within the HQET, the heavy to light vector meson transitions are
systematically analyzed to the order of 1/m_Q. Besides the four universal
functions at the leading order, there are twenty-two independent universal form
factors at the order of 1/m_Q. Both the semileptonic decay B->\rho which is
relevant to the |V_{ub}| extraction, and the penguin induced decay B -> K^*
which is important to new physics discovering, depend on these form factors.
Phenomenological implications are discussed.Comment: RevTeX, 9 pages, no figure
Top quark electric and chromo electric dipole moments in the general two Higgs Doublet model
We study the electric and chromo electric dipole moment of top quark in the
general two Higgs Doublet model (model III). We analyse the dependency of this
quantity to the new phases coming from the complex Yukawa couplings and masses
of charged and neutral Higgs bosons. We observe that the electric and chromo
elecric dipole moments of top quark are at the order of 10^{-21} e cm and
10^{-20} g_s cm, which are extremely large values compared to ones calculated
in the SM and also two Higgs Doublet model with real Yukawa couplings.Comment: 9 pages,10 figure
Distracted , Stressed, and Confused: The Effects of Distraction and Stress on Memory Retention
Previous research has tested the effects of test anxiety and memory impairment due to stress, but little research has investigated the interplay of these factors with environmental distraction. Our study aims to fill in this gap by examining the association between distraction, stress and information recall in an effort to identify optimal testing experiences within the academic environment. Professors and administrators can improve academic success based upon the knowledge of how stressful stimuli affects test performance.
In this experiment, we seek to establish a connection between stress, distraction, and memory recall within academic testing. By employing distracting stimuli in a controlled environment, we hope to uncover further insight into whether students perform better or worse in stressful environments. Understanding how added stressors influence student performance can help professors and administrators structure effective learning environments. Likewise, our findings might also add to our knowledge of the influence of marginal distractibility on the recall of class content. We speculate that there is an optimal range of distractibility and stress within the academic setting. Understanding how added stressors and distractions influence student performance can help college administrators structure effective learning environments.
During the experimental phase, our team examined the effects of stress on material recollection by using a graded versus an ungraded exam. We expected that the combination of stress and distracted conditions will result in a significantly diminished student memory performance, compared to the marginal declines caused by stress or distraction alone. Additionally, we explored the role of environmental distraction on memory performance by measuring how students responded to the sudden announcement of a graded test. We hypothesized that if a sudden stressor is presented, one will respond negatively, unable to recall the desired information. Thus, we expect the student to perform less successfully as one would without the stressor. We suspected that environmental noise and distractions increased, academic anxiety will increase as well, causing memory deficits for the affected students. Findings are under review, but are expected to support the stated hypotheses
From Tetraquark to Hexaquark: A Systematic Study of Heavy Exotics in the Large Limit
A systematic study of multiquark exotics with one or heavy quarks in
the large limit is presented. By binding a chiral soliton to a heavy
meson, either a normal -quark baryon or an exotic -quark baryon
is obtained. By replacing the heavy quark with heavy antiquarks, exotic
-quark and -quark mesons are obtained. When , they are
just the normal triquark baryon , the exotic pentaquark baryon , tetraquark di-meson and the hexaquark
di-baryon respectively. Their
stabilities and decays are also discussed. In particular, it is shown that the
``heavy to heavy'' semileptonic decays are described by the Isgur--Wise form
factors of the normal baryons.Comment: 14 pages in REVTeX, no Figure
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