67 research outputs found
Variation in the quality of meat from Irish steers at the time of slaughter.
End of Project ReportThere is no information on the variation in quality, in particular
tenderness, that exists in Irish Beef nor is there information on the
variation that would remain if optimum practices were imposed at
all stages of the beef production chain. Evaluation of the success of
measures to improve beef consistency requires information on
existing variation and the minimum variation achievable.The objectives
of this project were (i) to establish the variation that exists in
the quality of meat from Irish cattle, (ii) to quantify the minimum
variation in meat quality that can be achieved in a practical beef production
system, (iii) to determine the effects and mechanisms of
additional sources of variation.
The conclusions from this project are:
• The M. longissimus dorsi (loin) was found to be more variable
than the M. semimembranosus (topside) for most quality
attributes examined (tenderness, sarcomere length and pH).
The scale of variation within the loin was similar to that
reported by the other research groups within the EU and US.
Heifers were more variable than steers for most attributes,
while there was no consistent classification effect on the
variability of meat quality attributes.
• Tenderness was equally variable in meat from genetically similar
steers, managed similarly, compared to commercial steers
randomly selected from a factory lairage but matched for
weight and grade.This was likely a result of both groups being
crossbred beef cattle of similar age, fat score, carcass weight
and managed identically post-mortem. However, variation in
tenderness of both groups was less than that observed in
a survey of commercial throughput (experiment 1). This
decrease is attributed to better pre-and-post-slaughter handling
practices.
• The data suggest that selection of sires (within a breed) with
better than average conformation has no deleterious effect on the eating quality of beef of their progeny.A more comprehensive
comparison of sires within a breed and between
breeds is required to confirm the generality of this conclusion.
• In a comparison of genotypes, gender and slaughter weights,
there was no evidence that variation around the mean value
for tenderness differed between breeds or liveweights after
14 days ageing. Bulls were more variable than steers for some
quality traits but the variation in tenderness was similar for
bulls and steers after 14 days ageing.
• While optimising the management of animals during the pre
and post-slaughter period reduced variation in tenderness,
some residual variation remained. A large percentage of the
residual variation in tenderness (Warner Bratzler shear force)
after 2 and 7 days post-mortem was explained by proteolysis
(breakdown of myofibrillar proteins).Variation in tenderness
(Warner Bratzler shear force) after 2 days post-mortem was
largely explained by phosphates (energy) and proteolysis,
while sensory tenderness was largely explained by phosphates
and glycolytic potential.
• Further work is required to reduce residual variation in Irish
beef and to determine the causes of this variation
Football goal distributions and extremal statistics
We analyse the distributions of the number of goals scored by home teams, away teams, and the total scored in the match, in domestic football games from 169 countries between 1999 and 2001. The probability density functions (PDFs) of goals scored are too heavy-tailed to be fitted over their entire ranges by Poisson or negative binomial distributions which would be expected for uncorrelated processes. Log-normal distributions cannot include zero scores and here we find that the PDFs are consistent with those arising from extremal statistics. In addition, we show that it is sufficient to model English top division and FA Cup matches in the seasons of 1970/71–2000/01 on Poisson or negative binomial distributions, as reported in analyses of earlier seasons, and that these are not consistent with extremal statistics
The closest elastic tensor of arbitrary symmetry to an elasticity tensor of lower symmetry
The closest tensors of higher symmetry classes are derived in explicit form
for a given elasticity tensor of arbitrary symmetry. The mathematical problem
is to minimize the elastic length or distance between the given tensor and the
closest elasticity tensor of the specified symmetry. Solutions are presented
for three distance functions, with particular attention to the Riemannian and
log-Euclidean distances. These yield solutions that are invariant under
inversion, i.e., the same whether elastic stiffness or compliance are
considered. The Frobenius distance function, which corresponds to common
notions of Euclidean length, is not invariant although it is simple to apply
using projection operators. A complete description of the Euclidean projection
method is presented. The three metrics are considered at a level of detail far
greater than heretofore, as we develop the general framework to best fit a
given set of moduli onto higher elastic symmetries. The procedures for finding
the closest elasticity tensor are illustrated by application to a set of 21
moduli with no underlying symmetry.Comment: 48 pages, 1 figur
Selection of antigenically advanced variants of seasonal influenza viruses
Influenza viruses mutate frequently, necessitating constant updates of vaccine viruses. To establish experimental approaches that may complement the current vaccine strain selection process, we selected antigenic variants from human H1N1 and H3N2 influenza virus libraries possessing random mutations in the globular head of the haemagglutinin protein (which includes the antigenic sites) by incubating them with human and/or ferret convalescent se
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Efeito do grupo genético sobre as características de carcaça e maciez da carne fresca e maturada de bovinos superprecoces
Variation in the quality of meat from Irish steers at the time of slaughter.
End of Project ReportThere is no information on the variation in quality, in particular
tenderness, that exists in Irish Beef nor is there information on the
variation that would remain if optimum practices were imposed at
all stages of the beef production chain. Evaluation of the success of
measures to improve beef consistency requires information on
existing variation and the minimum variation achievable.The objectives
of this project were (i) to establish the variation that exists in
the quality of meat from Irish cattle, (ii) to quantify the minimum
variation in meat quality that can be achieved in a practical beef production
system, (iii) to determine the effects and mechanisms of
additional sources of variation.
The conclusions from this project are:
• The M. longissimus dorsi (loin) was found to be more variable
than the M. semimembranosus (topside) for most quality
attributes examined (tenderness, sarcomere length and pH).
The scale of variation within the loin was similar to that
reported by the other research groups within the EU and US.
Heifers were more variable than steers for most attributes,
while there was no consistent classification effect on the
variability of meat quality attributes.
• Tenderness was equally variable in meat from genetically similar
steers, managed similarly, compared to commercial steers
randomly selected from a factory lairage but matched for
weight and grade.This was likely a result of both groups being
crossbred beef cattle of similar age, fat score, carcass weight
and managed identically post-mortem. However, variation in
tenderness of both groups was less than that observed in
a survey of commercial throughput (experiment 1). This
decrease is attributed to better pre-and-post-slaughter handling
practices.
• The data suggest that selection of sires (within a breed) with
better than average conformation has no deleterious effect on the eating quality of beef of their progeny.A more comprehensive
comparison of sires within a breed and between
breeds is required to confirm the generality of this conclusion.
• In a comparison of genotypes, gender and slaughter weights,
there was no evidence that variation around the mean value
for tenderness differed between breeds or liveweights after
14 days ageing. Bulls were more variable than steers for some
quality traits but the variation in tenderness was similar for
bulls and steers after 14 days ageing.
• While optimising the management of animals during the pre
and post-slaughter period reduced variation in tenderness,
some residual variation remained. A large percentage of the
residual variation in tenderness (Warner Bratzler shear force)
after 2 and 7 days post-mortem was explained by proteolysis
(breakdown of myofibrillar proteins).Variation in tenderness
(Warner Bratzler shear force) after 2 days post-mortem was
largely explained by phosphates (energy) and proteolysis,
while sensory tenderness was largely explained by phosphates
and glycolytic potential.
• Further work is required to reduce residual variation in Irish
beef and to determine the causes of this variation
- …