Estimates for heritability and consumer-validation of a penetrometer method for phenotyping softness of cooked cassava roots

Although breeders have made significant progress in the genetic improvement of cassava ( Manihot esculenta Crantz) for agronomic traits, lack of information on heritability and limited testing of high-throughput phenotyping methods are major limitations to improving root quality traits, such as softness after cooking, which rank high among Ugandan consumers. The objectives of this study were to determine heritability for softness of cooked cassava roots, and quantify the relationship between penetrometer and consumer testing methods for phenotyping softness of cassava roots. Softness defined as the maximum force (N) needed to penetrate cooked root samples using a penetrometer, was evaluated at four cooking time intervals: 15, 30, 45, and 60 min on 268 cassava genotypes. Estimates of broad-sense heritability (repeatability) ranged from 0.17 to 0.37, with the highest value observed at 45 min of cooking time interval. In the second study involving 135 cassava consumers from Kibaale district in Uganda, penetrometer measurements of cooked roots from six cassava varieties were found to be in strong agreement (r2 = 0.91; P-value = 0.003) with ordinal scores of root softness from consumer testing. These results suggest that: (a) softness of cooked cassava roots is a trait amenable for evaluation and selection; and (b) a penetrometer can readily be used for assessment of cooked root softness. These findings form the basis for operationalising the routine assessment of root softness in cassava breeding trials, an output that will enhance ongoing efforts to breed for desired end-user root quality traits.Les s\ue9lectionneurs ont fait des progr\ue8s consid\ue9rables dans l\u2019am\ue9lioration g\ue9n\ue9tique des caract\ue8res agronomiques du manioc ( Manihot esculenta Crantz). Cependant un manque de m\ue9thodes de ph\ue9notypage haut-d\ue9bit adapt\ue9es aux caract\ue8res de qualit\ue9s tel que la fermet\ue9 de la racine apr\ue8s cuisson, essentiel pour les consommateurs Ougandais. Cette \ue9tude ambitionne a) de determiner l\u2019h\ue9ritabilit\ue9 de la fermete de racine cuite b) de quantifier la relation entre l \ue9valuation de la fermet\ue9 de racine cuite au p\ue9n\ue9trom\ue8tre et un panel consommateurs. Cette \ue9valuation a \ue9t\ue9 realisee a quatre intervals de temps: 15, 30, 45 et 60 minutes sur 268 genotypes de manioc. Pour d\ue9finir l\u2019h\ue9ritabilit\ue9 de la fermet\ue9 de la racine, celle ci a \ue9t\ue9 d\ue9finie par la force maximum (N) n\ue9cessaire pour p\ue9n\ue9trer des \ue9chantillons de racines incluant diff\ue8rent temps de cuisson (15, 30, 45, and 60 min) a l\u2019aide d\u2019un p\ue9n\ue9trom\ue8tre. L\u2019h\ue9ritabilit\ue9 au sens large (ou r\ue9p\ue9tabilit\ue9) observ\ue9e varie de 0.17 a 0.37, la valeur la plus \ue9lev\ue9 \ue9tant observ\ue9e pour un temps de cuisson de 45 minutes. Dans une seconde \ue9tude impliquant 135 consommateurs du district de Kibaale (Ouest de l\u2019Ouganda), les mesures au p\ue9n\ue9trom\ue8tre de racines cuites de six vari\ue9t\ue9s ont confirm\ue9es la forte correlation (r2 = 0.91; P-value = 0.003) avec les valeurs ordinales de fermet\ue9 de racine du panel consommateur. Les r\ue9sultats de cette \ue9tude indiquent que cette m\ue9thodologie de ph\ue9notypage est a) utile pour l\u2019 \ue9valuation de la fermet\ue9 sur des racines cuites en selection et b) d\ue9montre que l\u2019usage du p\ue9n\ue9trom\ue8tre est efficace pour celle ci. Ces r\ue9sultats offrent aux s\ue9lectionneurs une methode d\u2019 \ue9valuation de routine de la qualite de racine pour les essais experimentaux. Ceux ci contribueront aux efforts actuels pour l\u2019am\ue9lioration des caract\ue8res qualit\ue9s chers aux consommateurs

Parity nonconservation in deuteron photoreactions

We calculate the asymmetries in parity nonconserving deuteron photodisintegration due to circularly polarized photons gamma+d to n+p with the photon laboratory energy ranging from the threshold up to 10 MeV and the radiative capture of thermal polarized neutrons by protons n+p to gamma+d. We use the leading order electromagnetic Hamiltonian neglecting the smaller nuclear exchange currents. Comparative calculations are done by using the Reid93 and Argonne v18 potentials for the strong interaction and the DDH and FCDH "best" values for the weak couplings in a weak one-meson exchange potential. A weak NDelta transition potential is used to incorporate also the Delta(1232)-isobar excitation in the coupled-channels formalism.Comment: 14 pages, 13 figures (18 eps files), LaTeX2

The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new reference

Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set

This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of 3He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active 8B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54-0.31+0.33(stat.)-0.34+0.36(syst.)×106 cm-2 s-1, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Δm2=7.59-0.21+0.19×10 -5eV2 and θ=34.4-1.2+1.3degrees

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Recent results from SNO

The SNO project has now completed two of its three major phases of operation. The no-oscillation hypothesis has been ruled out at 5σ in the pure heavy water phase and 8σ in the salt phase. Discussion in terms of the SeeSaw model is presented