4,681 research outputs found
Extensions to the Estimation Calculus
Walther’s estimation calculus was designed to prove the termination of functional programs, and can also be used to solve the similar problem of proving the well-foundedness of induction rules. However, there are certain features of the goal formulae which are more common to the problem of induction rule well-foundedness than the problem of termination, and which the calculus cannot handle. We present a sound extension of the calculus that is capable of dealing with these features. The extension develops Walther’s concept of an argument bounded function in two ways: firstly, so that the function may be bounded below by its argument, and secondly, so that a bound may exist between two arguments of a predicate. Our calculus enables automatic proofs of the well-foundedness of a large class of induction rules not captured by the original calculus
Controlling evaporation loss from water storages
[Executive Summary]: Evaporation losses from on-farm storage can potentially be large, particularly in irrigation areas in northern New South Wales and Queensland where up to 40% of storage volume can be lost each year to evaporation. Reducing evaporation from a water storage would allow additional crop production, water trading or water for the environment. While theoretical research into evaporation from storages has previously been undertaken there has been little evaluation of current evaporation mitigation technologies (EMTs) on commercial sized water storages. This project was initiated by the Queensland Government Department of Natural Resources and Mines (NRM) with the express aim of addressing this gap in our knowledge. The report addressed i) assessment of the effectiveness of different EMT’s in reducing evaporation from commercial storages across a range of climate regions, ii) assessment of the practical and technical limitations of different evaporation control products, and iii) comparison of the economics of different EMT’s on water storages used for irrigation
Studies on ovine tumour necrosis factor-alpha
Tumour necrosis factor alpha (TNFa), a mediator of inflammatory
responses and pathologies of a wide variety of diseases, has been
extensively studied in humans and mice. However, little has previously
been known about this cytokine in the sheep, a species of value not
only to the agricultural industry, but also as a laboratory animal.In this work, the cDNA encoding ovine TNFa has been amplified,
cloned, sequenced and used to express recombinant ovine TNFa
(rovTNFa). The latter has been partially purified, characterised and
used to raise both poly- and mono-clonal antibodies.The sequence of ovine TNFa shows a high degree of homology to those
of other species. Certain regions, which are known to be structurally
or functionally important to the mRNA and/or protein, are particularly
well conserved. Consequently, rovTNFa displays several biological
activities previously noted for TNF'sa of other species, including
cytotoxicity, enhancement of thymocyte and fibroblast proliferation
and cartilage-degrading and anti-viral activities. However, whilst
rovTNFa is active in assays on ovine cells at concentrations
comparable to those observed in similar assays for other species, it
is 1000 fold less active than recombinant human TNFa (rhTNFa) in cyto¬
toxicity assays on TNF-sensitive murine (L929) cells, whose general
lack of species specificity allows their use in detecting TNF'sa from
many sources.A monoclonal antibody raised to rovTNFa detects a glycoprotein of
appropriate size for mature ovine TNFa in the supernatants of
stimulated ovine cell cultures. As in other species both ovine TNFa
mRNA and protein are rapidly inducible. Such supernatants repeatedly
have no activity in cytotoxicity assays (sensitive to 30pg rhTNFa/ml)
on L929 cells, in spite of many containing >lng ovine TNFa/ml. At
least one of these supernatants displays biological activity
attributable to TNFa (through its neutralisation by a polyclonal
antiserum raised to rovTNFa) in an assay on ovine cells. By comparing
the amino acid sequences of TNF'sa from many species and using
knowledge gained from structure/function studies on human TNFa,
possible explanations for the apparent species specificity of ovine
TNFa are proposed.Finally, preliminary investigations have been performed to examine
the role that TNFa plays in Maedi-Visna (MV) disease, a chronic lentivirally-induced ovine disease. RovTNFa can differentially regulate MV
viral expression in different cell types in vitro, whilst the native
protein is produced in MV-infected cultures of adherent ovine lung
cells. Ovine TNFa may therefore play a complex role in MV disease,
both by contributing to its pathogenesis and influencing the viral
life-cycle
Providential Capitalism: Heavenly Intervention and the Atlantic’s Divine Economist
Providential capitalism names the marriage of providential Christian values and market-oriented capitalist ideology in the post-revolutionary Atlantic through the mid nineteenth century. This is a process by which individuals permitted themselves to be used by a so-called “divine economist” at work in the Atlantic market economy. Backed by a slave market, capital transactions were rendered as often violent ecstatic individual and cultural experiences. Those experiences also formed the bases for national, racial, and classed identification and negotiation among the constellated communities of the Atlantic. With this in mind, writers like Benjamin Franklin, Olaudah Equiano, and Ukawsaw Gronniosaw presented market success as proof of divine election. At the same time, writers like Richard Henry Dana Jr., Royall Tyler, and the anonymous author of Humanity in Algiers offered hegemonic expansion as an integral part of a divine capitalist plan. However, writers like Ottobah Cugoano, Venture Smith, John Jea, and, later, Edgar Allan Poe, in The Narrative of Arthur Gordon Pym of Nantucket, and Herman Melville, in Redburn: His First Voyage, recognized the dehumanizing potential of this power arrangement. They described the ways in which humans could be commodified or rendered invisible by the operations of a market that used individuals for its own ends and maintained the aegis of divine sovereignty. Urban Gothic novels like Charles Brockden Brown’s Arthur Mervyn or Memoirs of the Year 1793 and George Lippard’s The Quaker City, or The Monks of Monk Hall likewise commented upon the unsettling nationalist stakes of this power structure. This project reorients Atlantic critical and literary studies around this conflation of interests, philosophies, and theologies, which became culturally formative in the revolutionary period, blossomed throughout the post-revolutionary era, and reached a point of crisis by the mid-nineteenth century. Building upon current Atlantic scholarship, it uses a disparate array of authors and texts to demonstrate the diversity of responses to the emergence, proliferation, and watershed of providential capitalism for Atlantic cultures and individuals
Isolation and characterization of microsatellites in the lichen Buellia frigida (Physciaceae), an Antarctic endemic
Premise of the study: Microsatellite markers were characterized for an Antarctic endemic, Buellia frigida, to investigate population structure and origin of Antarctic lichens.
Methods and Results: Five primer sets were characterized. All loci were polymorphic with eight to 16 alleles per locus in a sample of 59 lichens.
Conclusions: The microsatellite markers potentially provide insight into population structure and gene flow of B. frigida
Constructing A Flexible Likelihood Function For Spectroscopic Inference
We present a modular, extensible likelihood framework for spectroscopic
inference based on synthetic model spectra. The subtraction of an imperfect
model from a continuously sampled spectrum introduces covariance between
adjacent datapoints (pixels) into the residual spectrum. For the high
signal-to-noise data with large spectral range that is commonly employed in
stellar astrophysics, that covariant structure can lead to dramatically
underestimated parameter uncertainties (and, in some cases, biases). We
construct a likelihood function that accounts for the structure of the
covariance matrix, utilizing the machinery of Gaussian process kernels. This
framework specifically address the common problem of mismatches in model
spectral line strengths (with respect to data) due to intrinsic model
imperfections (e.g., in the atomic/molecular databases or opacity
prescriptions) by developing a novel local covariance kernel formalism that
identifies and self-consistently downweights pathological spectral line
"outliers." By fitting many spectra in a hierarchical manner, these local
kernels provide a mechanism to learn about and build data-driven corrections to
synthetic spectral libraries. An open-source software implementation of this
approach is available at http://iancze.github.io/Starfish, including a
sophisticated probabilistic scheme for spectral interpolation when using model
libraries that are sparsely sampled in the stellar parameters. We demonstrate
some salient features of the framework by fitting the high resolution -band
spectrum of WASP-14, an F5 dwarf with a transiting exoplanet, and the moderate
resolution -band spectrum of Gliese 51, an M5 field dwarf.Comment: Accepted to ApJ. Incorporated referees' comments. New figures 1, 8,
10, 12, and 14. Supplemental website: http://iancze.github.io/Starfish
Capping aspiration : the millennial housing challenge
Housing costs in the south east of England are unaffordable for millennials, even in social housing. And the Shared Accommodation Rate could cause severe hardship for single 16–34 year olds claiming Housing Benefit.
The housing aspirations identified during the research were tempered by realism, and younger people recognised the importance of increased earnings. However, most were pessimistic about the prospects of improving their housing situation.
In terms of developing viable housing offers to meet this group’s needs, housing associations are hampered by the nature of the homes they own; the procedures and protocols they share with their local authority partners in relation to allocating and managing those homes; and the impending risk of the Shared Accommodation Rate, which could make tenancies unsustainable
Using a generalisation critic to find bisimulations for coinductive proofs
Coinduction is a method of growing importance in reasoning about functional languages, due to the increasing prominence of lazy data structures. Through the use of bisimulations and proofs that observational equivalence is a congruence in various domains it can be used to proof the congruence of two processes. Several proof tools have been developed to aid coinductive proofs but all require user interaction. Crucially they require the user to supply an appropriate relation which the system can then prove to be a bisimulation. A method is proposed which uses the idea of proof plans to make a heuristic guess at a suitable relation. If the proof fails for that relation the reasons for failure are analysed using a proof critic and a new relation is proposed to allow the proof to go through
Architecture for Aboriginal children and families: a post occupancy evaluation of the Taikurrendi, Gabmididi Manoo and Ngura Yadurirn Children and Family Centres
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