52 research outputs found
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
Glauber Dynamics for the mean-field Potts Model
We study Glauber dynamics for the mean-field (Curie-Weiss) Potts model with
states and show that it undergoes a critical slowdown at an
inverse-temperature strictly lower than the critical
for uniqueness of the thermodynamic limit. The dynamical critical
is the spinodal point marking the onset of metastability.
We prove that when the mixing time is asymptotically
and the dynamics exhibits the cutoff phenomena, a sharp
transition in mixing, with a window of order . At the
dynamics no longer exhibits cutoff and its mixing obeys a power-law of order
. For the mixing time is exponentially large in
. Furthermore, as with , the mixing time
interpolates smoothly from subcritical to critical behavior, with the latter
reached at a scaling window of around . These results
form the first complete analysis of mixing around the critical dynamical
temperature --- including the critical power law --- for a model with a first
order phase transition.Comment: 45 pages, 5 figure
TGF-β2 decreases baseline and IL-13-stimulated mucin production by primary human bronchial epithelial cells
Cerebral Blood Volume Changes Measured with MRI in Rats with Administration of the Serotonin-1A Agonist 8-OH-DPAT
Investigation of deposition parameters for the non-aqueous electroplating of CdTe films and application in electrochemical photovoltaic cells
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