842 research outputs found
AFLP/SSR mapping of resistance genes to Alectra vogelii in cowpea (Vigna unguiculata l. Walp)
The parasite weed Alectra vogelii (Benth) causes significant yield reduction of cowpea in Africa. To find and map the resistance gene to A. vogelii in cowpea, a F2 population from a cross involving a resistant parent IT81D-994 and a susceptible TVX3236 was screened. Amplified fragment length polymorphism (AFLP) in combination with Single Sequence Repeat (SSR) analysis was used to identify markers that may be linked to the gene Rav3 conferring resistance to A. vogelii in the cowpea cultivar IT81D-994. The analysis of F2 individuals scored for resistance showedthat a single dominant gene conditioned A. vogelii resistance in IT81D-994 with a probability of 30 to 50%. Sixty-six AFLP/SSR markers were identified. Using MAPMAKER, four linkage groups were found. The first group showed 33 markers linked to the susceptible gene. The closest identified marker was 21.4 centimorgans away from the susceptible gene. The primer combination that showed the closest linkage was 809ACG8 (E-ACG 8 + UBC-809). The second group indicated 4 markers linked together while the third and the fourth groups showed 2 markers linkedtogether respectively. No markers were found linked to the resistance gene Rav3 conferring the resistance in the cultivated cowpea cultivar IT81D-994.La plante parasite Alectra vogelii (Benth) provoque une rĂ©duction significative du rendement de niĂ©bĂ© en Afrique. Pour repĂ©rer et cartographier le gĂšne de rĂ©sistance Ă A. vogelii, une population F2 issue dâun croisement impliquant le cultivar rĂ©sistant IT81D-994 et le cultivar sensible TVX3236 a Ă©tĂ© criblĂ©e. La technique Amplified fragment length polymorphism (AFLP) en combinaison avec des SĂ©quences Simples RĂ©pĂ©tĂ©s (SSR) a Ă©tĂ© utilisĂ©e pour identifier les marqueurs qui seraient liĂ©s au gĂšne Rav3 qui confĂšre la rĂ©sistance Ă A. vogelii chez le cultivar de niĂ©bĂ© IT81D- 994. Lâanalyse des individus F2 montrant une rĂ©sistance indique quâun seul gĂšne dominant conditionne la rĂ©sistance Ă A. vogelii chez IT81D-994 avec une probabilitĂ© de 30 Ă 50 %. Soixante six marqueurs AFLP/SSR ont Ă©tĂ© identifiĂ©s. A lâaide de MAPMAKER, 4 groupes de liaison ont Ă©tĂ© trouvĂ©s. Le premier groupe montre 33 marqueurs liĂ©s au gĂšne sensible. Le marqueur le plus proche identifiĂ© est Ă 21.4 centimorgans du gĂšne sensible. La combinaison dâamorces ayant des liaisons les plus proches Ă©tait 809ACG8 (E-ACG 8 + UBC-809). Le secondgroupe montre 4 marqueurs liĂ©s ensemble tandis que le troisiĂšme et le quatriĂšme groupe montrent 2 marqueurs liĂ©s entre eux respectivement. Aucun marqueur nâa Ă©tĂ© trouvĂ© liĂ© au gĂšne Rav3 qui confĂšre la rĂ©sistance au cultivar de niĂ©bĂ© cultivĂ© IT81D-994.Key words: Parasite, weeds, legumes, molecular marker
Combining Experiment and Theory to Elucidate the Role of Supercritical Water in Sulfide Decomposition
The cleavage of CâS linkages plays a key role in fuel processing and organic geochemistry. Water is known to affect these processes, and several hypotheses have been proposed, but the mechanism has been elusive. Here we use both experiment and theory to demonstrate that supercritical water reacts with intermediates formed during alkyl sulfide decomposition. During hexyl sulfide decomposition in supercritical water, pentane and CO + CO2 were detected in addition to the expected six carbon products. A multi-step reaction sequence for hexyl sulfide reacting with supercritical water is proposed which explains the surprising products, and quantum chemical calculations provide quantitative rates that support the proposed mechanism. The key sequence is cleavage of one CâS bond to form a thioaldehyde via radical reactions, followed by a pericyclic addition of water to the CS bond to form a geminal mercaptoalcohol. The mercaptoalcohol decomposes into an aldehyde and H2S either directly or via a water-catalyzed 6-membered ring transition state. The aldehyde quickly decomposes into CO plus pentane by radical reactions. The time is ripe for quantitative modelling of organosulfur reaction kinetics based on modern quantum chemistry
Addressing substance abuse and violence in substance use disorder treatment and batterer intervention programs
Background
Substance use disorders and perpetration of intimate partner violence (IPV) are interrelated, major public health problems. Methods
We surveyed directors of a sample of substance use disorder treatment programs (SUDPs; N=241) and batterer intervention programs (BIPs; N=235) in California (70% response rate) to examine the extent to which SUDPs address IPV, and BIPs address substance abuse. Results
Generally, SUDPs were not addressing co-occurring IPV perpetration in a formal and comprehensive way. Few had a policy requiring assessment of potential clients, or monitoring of admitted clients, for violence perpetration; almost one-quarter did not admit potential clients who had perpetrated IPV, and only 20% had a component or track to address violence. About one-third suspended or terminated clients engaging in violence. The most common barriers to SUDPs providing IPV services were that violence prevention was not part of the programâs mission, staff lacked training in violence, and the lack of reimbursement mechanisms for such services. In contrast, BIPs tended to address substance abuse in a more formal and comprehensive way; e.g., one-half had a policy requiring potential clients to be assessed, two-thirds required monitoring of substance abuse among admitted clients, and almost one-half had a component or track to address substance abuse. SUDPs had clients with fewer resources (marriage, employment, income, housing), and more severe problems (both alcohol and drug use disorders, dual substance use and other mental health disorders, HIV + status). We found little evidence that services are centralized for individuals with both substance abuse and violence problems, even though most SUDP and BIP directors agreed that help for both problems should be obtained simultaneously in separate programs. Conclusions
SUDPs may have difficulty addressing violence because they have a clientele with relatively few resources and more complex psychological and medical needs. However, policy change can modify barriers to treatment integration and service linkage, such as reimbursement restrictions and lack of staff training
Progress with the Upgrade of the SPS for the HL-LHC Era
The demanding beam performance requirements of the High Luminosity (HL-) LHC
project translate into a set of requirements and upgrade paths for the LHC
injector complex. In this paper the performance requirements for the SPS and
the known limitations are reviewed in the light of the 2012 operational
experience. The various SPS upgrades in progress and still under consideration
are described, in addition to the machine studies and simulations performed in
2012. The expected machine performance reach is estimated on the basis of the
present knowledge, and the remaining decisions that still need to be made
concerning upgrade options are detailed.Comment: 3 p. Presented at 4th International Particle Accelerator Conference
(IPAC 2013
The Demonstration of a Light Extinction Tomography System at the NASA Glenn Research Center's Icing Research Tunnel
A prototype light extinction tomography system has been developed for acquiring real-time in-situ icing cloud uniformity and density measurements in the NASA Glenn Research Center's Icing Research Tunnel (IRT). These measurements are currently obtained through periodic manual calibrations of the IRT. These calibrations are time consuming and assume that cloud uniformity and density does not greatly vary between the periodic calibrations. It is envisioned that the new light extinction tomography system will provide the means to make these measurements in-situ in real-time and minimize the need for these manual calibrations. This new system uses the principle of light extinction tomography to measure the spray density and distribution in the test section. The prototype system was installed and successfully demonstrated in the Icing Research Tunnel in early 2018. Data sets were acquired for several standard spray and simulated fault conditions to assess system capability and sensitivity. This paper will describe the prototype light extinction system, the theory behind it, and the results of the demonstration test that was conducted in the IRT
Semidiurnal Internal Tide Energy Fluxes and Their Variability in a Global Ocean Model and Moored Observations
We examine the temporal means and variability of the semidiurnal internal tide energy fluxes in 1/25° global simulations of the Hybrid Coordinate Ocean Model (HYCOM) and in a global archive of 79 historical moorings. Low-frequency flows, a major cause of internal tide variability, have comparable kinetic energies at the mooring sites in model and observations. The computed root-mean-square (RMS) variability of the energy flux is large in both model and observations and correlates positively with the time-averaged flux magnitude. Outside of strong generation regions, the normalized RMS variability (the RMS variability divided by the mean) is nearly independent of the flux magnitudes in the model, and of order 23% or more in both the model and observations. The spatially averaged flux magnitudes in observations and the simulation agree to within a factor of about 1.4 and 2.4 for vertical mode-1 and mode-2, respectively. The difference in energy flux computed from the full-depth model output versus model output subsampled at mooring instrument depths is small. The global historical archive is supplemented with six high-vertical resolution moorings from the Internal Waves Across the Pacific (IWAP) experiment. The model fluxes agree more closely with the high-resolution IWAP fluxes than with the historical mooring fluxes. The high variability in internal tide energy fluxes implies that internal tide fluxes computed from short observational records should be regarded as realizations of a highly variable field, not as âmeansâ that are indicative of conditions at the measurement sites over all time
- âŠ