6,216 research outputs found
Anisotropic pore fabrics in faulted porous sandstones
Thanks to SEM technician Peter Chung at the University of Glasgow, David Wilde and Peter Greatbatch at Keele University for careful thin section preparation, Chris Wibberley and Tom Blenkinsop for input and Kieran Keith from Harlaw Academy, Aberdeen for help collecting petrophysical data. Thanks to Fabrizio Storti, Michael Heap and Toru Takeshita for helping to improve this paper with their constructive reviews. This work forms part of a NERC Standard award for DH (NE/N003063/1), which is gratefully acknowledged.Peer reviewedPublisher PD
A hedonic model of lamb carcass attributes
Lamb carcass value is widely reported to be a function of lean meat yield, which is the relationship between muscle, fat and bone. Five retailers and five wholesalers assessed 47 lamb carcasses from diverse genotypes and scored seven attributes. A hedonic model reveals that conformation attributes were more highly valued (16 c/kg) relative to yield characteristics (4 c/kg). Meat colour and fat distribution were significant for retailers, but less important for wholesalers. Genotype was not a strong indicator of conformation. Eye muscle area and depth were correlated with Fat C; however, these were not significant. These results indicate that carcass conformation, meat colour and fat distribution should be incorporated into carcass grading models.Hedonic, lamb, conformation and meat value, attributes, Livestock Production/Industries,
Strategy is key in assessing the proportionality of the Single Transferable Vote
The Single Transferrable Vote is in use in several countries, most notably Australia, Ireland, India, and Scotland. It is held up as one of the more proportional systems, and frequently advocated as an alternative to the First Past the Post system in use in the UK. But just how proportional is it? David Farrell argues that determining the answer rests on understanding party strategy
The Irish Constitutional Convention offers a potential routemap for renewing UK democracy
If the UK were to carry out a citizens convention, what should it look like? David Farrell, the Research Director of the Irish Constitutional Convention describes how the Irish model works, and recommends that the UK follow its lead, given the constitutional uncertainties following the Scottish independence referendum, the prospect of âEnglish Votes for English Lawsâ and a potential referendum on our European Union membershi
The John Sebastian Helmcken Medical Collection: The Material History of Nineteenth-Century Medical Practitioner's Armamentarium
This article proposes that museums with history collections practise material history methodologies. Using the example of the John Sebastian Helmcken Medical Collection - a collection of nineteenth-century medical instruments from a historic site in Victoria, British Columbia - the author illustrates how information abstracted from artifacts can be useful for interpretation. Further, this artifact analysis demonstrates how an assemblage of objects created by someone in the past can be analyzed using the same material history methodologies developed for single artifacts.
Résumé
Cet article recommande que les musĂ©es Ă col-lections historiques mettent en pratique les mĂ©thodologies Ă©tablies en histoire de la cul-ture matĂ©rielle. Partant de l'exemple de la col-lection mĂ©dicale John Sebastian Helmcken, une collection d'instruments mĂ©dicaux du XIXe siĂšcle provenant d'un site historique de Victo-ria (Colombie-Britannique), l'auteur illustre la façon dont l'information tirĂ©e des objets façon-nĂ©s peut ĂȘtre utile Ă l'interprĂ©tation. De plus, cette analyse d'objets façonnĂ©s dĂ©montre qu'une collection d'articles rassemblĂ©s par quelqu'un dans le passĂ© peut ĂȘtre analysĂ©e Ă l'aide des mĂȘmes mĂ©thodes Ă©tablies en histoire de la culture matĂ©rielle que celles qui servent Ă l'Ă©tude d'objets façonnĂ©s distincts
Welfare Time Limits: An Update on State Policies, Implementation, and Effects on Families
One of the most controversial features of the 1990s welfare reforms was the imposition of time limits on benefit receipt. This comprehensive review, written by The Lewin Group and MDRC, includes analyses of administrative data reported by states to the federal government, visits to several states, and a literature review
The High Consistency Refining of Reclaimed Paper Stock
By subjecting reclaimed paper stock to high consistency refining (HCR) the strength of the paper was developed, without having an adverse effect on the drainage. HCR was performed on the stock at (29% ± 1%) consistency in a Bauer single disc refiner. The HCR stock was compared to conventional refining at 4.5% consistency, which was also refined in the disc refiner.
It was shown that the conventional refining of the paper stock has an adverse effect on drainage because it developed a large percentage of fines and shives. It is believed that these were developed because the reclaimed paper stock fiber is less flexible and that the conventional refining is a more severe process than HCR. When refining the paper stock under high consistency conditions the mullen and tensile were developed without producing the fines and shives, and therefore the drainage was not effected
A hierarchical Bayesian model for predicting ecological interactions using scaled evolutionary relationships
Identifying undocumented or potential future interactions among species is a
challenge facing modern ecologists. Recent link prediction methods rely on
trait data, however large species interaction databases are typically sparse
and covariates are limited to only a fraction of species. On the other hand,
evolutionary relationships, encoded as phylogenetic trees, can act as proxies
for underlying traits and historical patterns of parasite sharing among hosts.
We show that using a network-based conditional model, phylogenetic information
provides strong predictive power in a recently published global database of
host-parasite interactions. By scaling the phylogeny using an evolutionary
model, our method allows for biological interpretation often missing from
latent variable models. To further improve on the phylogeny-only model, we
combine a hierarchical Bayesian latent score framework for bipartite graphs
that accounts for the number of interactions per species with the host
dependence informed by phylogeny. Combining the two information sources yields
significant improvement in predictive accuracy over each of the submodels
alone. As many interaction networks are constructed from presence-only data, we
extend the model by integrating a correction mechanism for missing
interactions, which proves valuable in reducing uncertainty in unobserved
interactions.Comment: To appear in the Annals of Applied Statistic
Attempted DNA extraction from a Rancho La Brea Columbian mammoth (Mammuthus columbi): prospects for ancient DNA from asphalt deposits.
Fossil-bearing asphalt deposits are an understudied and potentially significant source of ancient DNA. Previous attempts to extract DNA from skeletons preserved at the Rancho La Brea tar pits in Los Angeles, California, have proven unsuccessful, but it is unclear whether this is due to a lack of endogenous DNA, or if the problem is caused by asphalt-mediated inhibition. In an attempt to test these hypotheses, a recently recovered Columbian mammoth (Mammuthus columbi) skeleton with an unusual pattern of asphalt impregnation was studied. Ultimately, none of the bone samples tested successfully amplified M.âcolumbi DNA. Our work suggests that reagents typically used to remove asphalt from ancient samples also inhibit DNA extraction. Ultimately, we conclude that the probability of recovering ancient DNA from fossils in asphalt deposits is strongly (perhaps fatally) hindered by the organic compounds that permeate the bones and that at the Rancho La Brea tar pits, environmental conditions might not have been ideal for the general preservation of genetic material
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