Applying SNP marker technology in the cacao breeding programme in Ghana

In this investigation 45 parental cacao plants and five progeny derived from the parental stock studied were genotyped using six SNP markers to determine off-types or mislabeled clones and to authenticate crosses made in the Cocoa Research Institute of Ghana (CRIG) breeding programme. Investigation was based on the 5\u2019 nuclease SNPassay using Illustra Hot Start mix Ready-To-Go PCR strips and BioTek FLx800TBP Fluorescence Microplate Reader. In a group of six cacao plants labeled as PA150 clones and another five labeled as Pound7, one clone in each group was unambiguously determined as off-type or mislabeled. Similarly, in a cohort of 23 PA7 "clones", four genotypes were differentiated. Cross-checking the fidelity of five progeny from the parental stock under study, it was established that no errors were made in the crossing. The most significant outcome of this study, however, was that out of the four categories of 23 PA7 candidate parental trees only one category can be comparable to the reference clone in the International Cacao Germplasm collection, Trinidad (ICG,T); thus informing the need for further work to find the correct clone among these for the breeding programme. It was thus concluded that thissimple yet cutting-edge genotyping procedure can be used in applied cocoa breeding programmes in a cocoa producing country. This work represents a first step in the genotypic characterisation of the CRIG germplasm collection and Seed Gardens.Au cours de cette recherche, 45 plants de cacao parentaux et 5 descendants d\ue9rivant du stock parental ont \ue9t\ue9 g\ue9notyp\ue9 en utilisant 6 marqueurs SNP, afin de d\ue9terminer les clones mal \ue9tiquet\ue9s et d\u2019authentifier les croisements effectu\ue9s dans le programme d\u2019am\ue9lioration de l\u2019Institut de Recherche sur le Cacao au Ghana (CRIG). Cette \ue9tude a \ue9t\ue9 bas\ue9e sur les 5' nucl\ue9ases SNP en utilisant des bandes PCR "Hot Start mix Ready-To-Go PCR strips" et un Lecteur Microplat \ue0 Fluorescence "BioTek FLx800TBP". Au sein d\u2019un groupe de six plants de cacao \ue9tiquet\ue9 PA150 et d\u2019un autre groupe de cinq \ue9tiquet\ue9 Pound 7, il a \ue9t\ue9 d\ue9termin\ue9 sans ambigu\ueft\ue9 qu\u2019un clone par groupe \ue9tait mal \ue9tiquet\ue9. De fa\ue7on similaire, quatre g\ue9notypes diff\ue9rents ont \ue9t\ue9 identifi\ue9s dans une m\ueame cohorte de clones 23PA7. En v\ue9rifiant la fid\ue9lit\ue9 de cinq descendants issus du stock parental \ue9tudi\ue9, il a \ue9t\ue9 \ue9tabli qu\u2019aucune erreur n\u2019avait \ue9t\ue9 faite lors du croisement. Le r\ue9sultat le plus significatif de cette \ue9tude a \ue9t\ue9 que, sur quatre cat\ue9gories de 23 candidats PA7 de souches parentales, une seule pouvait \ueatre comparable au clone de r\ue9f\ue9rence dans la collection Internationale du Germoplasme de Cacao, Trinidad (ICG,T), d\ue9montrant ainsi la n\ue9cessit\ue9 de travaux suppl\ue9mentaires pour d\ue9terminer le clone exact parmi ceux \ue9voqu\ue9s pr\ue9c\ue9demment. Il a ainsi \ue9t\ue9 conclu que cette m\ue9thode avant-gardiste de g\ue9notypage, pourtantsimple, peut \ueatre utilis\ue9e dans les programmes appliqu\ue9s d\u2019am\ue9lioration du cacao dans un pays producteur. Ce travail repr\ue9sente une premi\ue8re \ue9tape dans la caract\ue9risation g\ue9n\ue9tique de la collection du germoplasme CRIG et jardins semenciers

Different Photostability of BiVO4 in Near pH Neutral Electrolytes

Photoelectrochemical water splitting is a promising route to produce hydrogen from solar energy. However, corrosion of photo electrodes remains a fundamental challenge for their implementation. Here, we reveal different dissolution behaviors ofBiVO4photoanode in pH-buffered borate, phosphate, and citrate (hole-scavenger)electrolytes, studied in operandoemploying an illuminated scanning flow cell. We demonstrate that decrease in photocurrents alone does not reflect the degradation of photo electrodes. Changes in dissolution rates correlate to the evolution of surface chemistry and morphology. The correlative measurements on both sides of the liquid−semiconductor junction provide quantitative comparison and mechanistic insights into the degradation processes

Measurement of the Proton Spin Structure Function g1p with a Pure Hydrogen Target

A measurement of the proton spin structure function g1p(x,Q^2) in deep-inelastic scattering is presented. The data were taken with the 27.6 GeV longitudinally polarised positron beam at HERA incident on a longitudinally polarised pure hydrogen gas target internal to the storage ring. The kinematic range is 0.021<x<0.85 and 0.8 GeV^2<Q^2<20 GeV^2. The integral Int_{0.021}^{0.85} g1p(x)dx evaluated at Q0^2 of 2.5 GeV^2 is 0.122+/-0.003(stat.)+/-0.010(syst.).Comment: 7 pages, 3 figures, 1 table, RevTeX late

Observation of a Coherence Length Effect in Exclusive Rho^0 Electroproduction

Exclusive incoherent electroproduction of the rho^0(770) meson from 1H, 2H, 3He, and 14N targets has been studied by the HERMES experiment at squared four-momentum transfer Q**2>0.4 GeV**2 and positron energy loss nu from 9 to 20 GeV. The ratio of the 14N to 1H cross sections per nucleon, known as the nuclear transparency, was found to decrease with increasing coherence length of quark-antiquark fluctuations of the virtual photon. The data provide clear evidence of the interaction of the quark- antiquark fluctuations with the nuclear medium.Comment: RevTeX, 5 pages, 3 figure

Determination of the Deep Inelastic Contribution to the Generalised Gerasimov-Drell-Hearn Integral for the Proton and Neutron

The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2] for the proton and neutron have been determined from measurements of polarised cross section asymmetries in deep inelastic scattering of 27.5 GeV longitudinally polarised positrons from polarised 1H and 3He internal gas targets. The data were collected in the region above the nucleon resonances in the kinematic range nu < 23.5 GeV and 0.8 GeV**2 < Q**2 < 12 GeV**2. For the proton the contribution to the generalised Gerasimov-Drell-Hearn integral was found to be substantial and must be included for an accurate determination of the full integral. Furthermore the data are consistent with a QCD next-to-leading order fit based on previous deep inelastic scattering data. Therefore higher twist effects do not appear significant.Comment: 6 pages, 3 figures, 1 table, revte

Flavor Decomposition of the Polarized Quark Distributions in the Nucleon from Inclusive and Semi-inclusive Deep-inelastic Scattering

Spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons have been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and 3He targets, in the kinematic range 0.023<x<0.6 and 1 GeV^2<Q^2<10 GeV^2. Polarized quark distributions are extracted as a function of x for up $(u+u_bar) and down (d+d_bar) flavors. The up quark polarization is positive and the down quark polarization is negative in the measured range. The polarization of the sea is compatible with zero. The first moments of the polarized quark distributions are presented. The isospin non-singlet combination Delta_q_3 is consistent with the prediction based on the Bjorken sum rule. The moments of the polarized quark distributions are compared to predictions based on SU(3)_f flavor symmetry and to a prediction from lattice QCD.Comment: 14 pages, 6 figures (eps format), 10 tables in Latex New version contains tables of asymmetries and correlation matri

Gluons and the quark sea at high energies: distributions, polarization, tomography

This report is based on a ten-week program on "Gluons and the quark sea at high-energies", which took place at the Institute for Nuclear Theory in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science case for an Electron-Ion Collider (EIC), a facility that will be able to collide electrons and positrons with polarized protons and with light to heavy nuclei at high energies, offering unprecedented possibilities for in-depth studies of quantum chromodynamics. This report is organized around four major themes: i) the spin and flavor structure of the proton, ii) three-dimensional structure of nucleons and nuclei in momentum and configuration space, iii) QCD matter in nuclei, and iv) Electroweak physics and the search for physics beyond the Standard Model. Beginning with an executive summary, the report contains tables of key measurements, chapter overviews for each of the major scientific themes, and detailed individual contributions on various aspects of the scientific opportunities presented by an EIC.Comment: 547 pages, A report on the joint BNL/INT/Jlab program on the science case for an Electron-Ion Collider, September 13 to November 19, 2010, Institute for Nuclear Theory, Seattle; v2 with minor changes, matches printed versio

Measurement of D0-D0 mixing and search for CP violation in D0→K+K-,π+π- decays with the full Belle data set

We report an improved measurement of D0 – D‾0 mixing and a search for CP violation in D0 decays to CP -even final states K+K− and π+π− . The measurement is based on the final Belle data sample of 976 fb −1 . The results are yCP=(1.11±0.22±0.09)% and AΓ=(−0.03±0.20±0.07)% , where the first uncertainty is statistical and the second is systematic