2,791 research outputs found
Partial-Wave Analysis of Single-Pion Production Reactions
We present an overview of our efforts to analyze pion-nucleon elastic
scattering data, along with data from related photo- and electroproduction
reactions, in order to study the baryon spectrum. We then focus on the
Delta(1232) resonance. Fits to pion photo- and electroproduction data have been
used to extract values for the R_EM = E2/M1 and R_SM = S2/M1 ratios as
functions of Q^2. These results are compared to other recent determinations.Comment: 7 pages, 9 figures, the Shape of Hadrons Workshop Proceedings (27-29
April, 2006 Athens, Greece
Evaluation of Sediment and Nutrient Loss during the Revegetation of Mississippi Roadsides
Runoff during the revegetation of roadsides can transport sediment and nutrients offsite, leading to surface water quality reductions. Two field experiments were conducted near Starkville, MS in 2011 and 2012 to evaluate the influence of N and P sources and rates, fertilization timing, and mulch type on vegetative establishment and nutrient and sediment runoff losses. Stainless steel runoff frames (0.75 x 2.0 m) were installed on 10% and 15% slopes for Experiment I and Experiment II, respectively. A bahiagrass (Paspalum notatum Flugge), tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.], sericea lespedeza [Lespedeza cuneata (Dum. Cours.) G. Don], and common bermudagrass [Cynodon dactylon (L.) Pers.] mixture was seeded within each frame during Experiment I. Crimson clover (Trifolium incarnatum L.) was added for Experiment II. Experiment I treatments consisted of 73.5 or 147 kg N ha-1 as 13-13-13, poultry litter, ammonium nitrate, stabilized urea, polymer coated urea, or diammonium phosphate. Experiment II treatments consisted of wheat straw and six hydromulches; paper fiber, wood fiber, wood/paper fiber blend, flexible growth medium (FGM), extended term-FGM (ET-FGM), bonded fiber matrix (BFM). Runoff from natural and simulated rainfall was analyzed for PO43--P, total P (TP), NH4+-N, NO3- -N, total N (TN), and total solids (TS). Experiment I results suggest the greatest N and P runoff losses occurred during the first runoff event following fertilization. Splitting 147 kg N ha-1 into two equal applications increased nutrient losses compared to one application. Application of organic plus inorganic P increased PO43--P in runoff compared to inorganic P alone. Experiment II results indicate straw was the most effective mulch for increasing vegetative establishment and limiting solids and nutrients in runoff. However, lack of fertilizer prill dissolution may have influenced nutrient runoff losses during dry conditions. The FGM, ET-FGM, and BFM mulch treatments were more effective than the paper, wood, and paper/wood fiber treatments in reducing solids and nutrients in runoff. It was apparent during both experiments that timing, intensity, and duration of rainfall events following fertilization have an influence on runoff losses. However, further research is needed to quantify the influence of those rainfall parameters
Results from the Analysis of Crystal Ball Meson Production Measurements at BNL
The Crystal Ball spectrometer, with its nearly complete angular coverage, is
an efficient detector of photon and neutron final states. While installed in
the C6 beamline of the Alternating Gradient Synchrotron (AGS) of Brookhaven
National Laboratory (BNL), this feature was used in a series of precise
measurements of reactions with all-neutral final states. Here we concentrate on
the analysis of data from the pion-induced reactions: pi- p --> gamma n, pi- p
--> pi0 n, pi- p --> eta n, and pi- p --> pi0 pi0 n.Comment: Conference contribution to MESON 2006 - Krakow, Pola
Recommended from our members
A two-step method for identifying photopigment opsin and rhodopsin gene sequences underlying human color vision phenotypes.
PurposeTo present a detailed, reliable long range-PCR and sequencing (LR-PCR-Seq) procedure to identify human opsin gene sequences for variations in the long wavelength-sensitive (OPN1LW), medium wavelength-sensitive (OPN1MW), short wavelength-sensitive (OPN1SW), and rhodopsin (RHO) genes.MethodsColor vision was assessed for nine subjects using the Farnsworth-Munsell 100 hue test, Ishihara pseudoisochromatic plates, and the Rabin cone-contrast threshold procedure (ColorDX, Konan Medical). The color vision phenotypes were normal trichromacy (n = 3), potential tetrachromacy (n = 3), dichromacy (n = 2), and unexplained low color vision (n = 1). DNA was isolated from blood or saliva and LR-PCR amplified into individual products: OPN1LW (4,045 bp), OPN1MW (4,045 bp), OPN1SW (3,326 bp), and RHO (6,715 bp). Each product was sequenced using specific internal primer sets. Analysis was performed with Mutation Surveyor software.ResultsThe LR-PCR-Seq technique identified known single nucleotide polymorphisms (SNPs) in OPN1LW and OPN1MW gene codons (180, 230, 233, 277, and 285), as well as those for lesser studied codons (174, 178, 236, 274, 279, 298 and 309) in the OPN1LW and OPN1MW genes. Additionally, six SNP variants in the OPN1MW and OPN1LW genes not previously reported in the NCBI dbSNP database were identified. An unreported poly-T region within intron 5(c.36+126) of the rhodopsin gene was also found, and analysis showed it to be highly conserved in mammalian species.ConclusionsThis LR-PCR-Seq procedure (single PCR reaction per gene followed by sequencing) can identify exonic and intronic SNP variants in OPN1LW, OPN1MW, OPN1SW, and rhodopsin genes. There is no need for restriction enzyme digestion or multiple PCR steps that can introduce errors. Future studies will combine the LR-PCR-Seq with perceptual behavior measures, allowing for accurate correlations between opsin genotypes, retinal photopigment phenotypes, and color perception behaviors
- …