1,719 research outputs found
Short-term effect of soil disturbance by mechanical weeding on plant available nutrients in an organic vs conventional rotations experiment
The question whether soil disturbance from mechanical weeding in organic systems affects nutrient release from organic matter in compost-amended soil was examined in a long-term organic-versus-conventional rotational cropping system experiment over three years. The experimental design included continuous snap beans, and a fully phased snap beans/fall rye crop rotation sequence. Treatments were combinations of yearly applied fertiliser (synthetic fertiliser, 1× compost, 3× compost) and weed control (herbicide, mechanical weeding). The 1× compost rate was calculated to deliver the equivalent of 50 kg N ha-1: equal to the rate ofN in the synthetic fertiliser treatments. Ion exchange membranes were buried for 24 hours following mechanical weeding in bean plots. Adsorbed ions were then eluted and quantified. Available ammonium-nitrogen was not affected byweeding treatment, but nitrate-nitrogen was consistently less in mechanically weeded plots than in plots treated with herbicide. Principal component analysis of NH4-N, NO3-N, P, K, Ca and Mg availabilities showed distinct groupings of treatments according to fertility treatment rather than weeding treatment. The effect of cropping sequence on available nutrients was pronounced (P ≤ 0.001) only in plots amended with synthetic fertilisers
Cotreatment with a novel phosphoinositide analogue inhibitor and carmustine enhances chemotherapeutic efficacy by attenuating AKT activity in gliomas
Controlled Natural Language Generation from a Multilingual FrameNet-based Grammar
This paper presents a currently bilingual but potentially multilingual
FrameNet-based grammar library implemented in Grammatical Framework. The
contribution of this paper is two-fold. First, it offers a methodological
approach to automatically generate the grammar based on semantico-syntactic
valence patterns extracted from FrameNet-annotated corpora. Second, it provides
a proof of concept for two use cases illustrating how the acquired multilingual
grammar can be exploited in different CNL applications in the domains of arts
and tourism
Cross-language frame semantics transfer in bilingual corpora
Abstract. Recent work on the transfer of semantic information across languages has been recently applied to the development of resources annotated with Frame information for different non-English European languages. These works are based on the assumption that parallel corpora annotated for English can be used to transfer the semantic information to the other target languages. In this paper, a robust method based on a statistical machine translation step augmented with simple rule-based post-processing is presented. It alleviates problems related to preprocessing errors and the complex optimization required by syntax-dependent models of the cross-lingual mapping. Different alignment strategies are here in-vestigated against the Europarl corpus. Results suggest that the quality of the de-rived annotations is surprisingly good and well suited for training semantic role labeling systems.
Dark Matter Caustics
Caustics are a generic feature of the nonlinear growth of structure in the
dark matter distribution. If the dark matter were absolutely cold, its mass
density would diverge at caustics, and the integrated annihilation probability
would also diverge for individual particles participating in them. For
realistic dark matter candidates, this behaviour is regularised by small but
non-zero initial thermal velocities. We present a mathematical treatment of
evolution from Hot, Warm or Cold Dark Matter initial conditions which can be
directly implemented in cosmological N-body codes. It allows the identification
of caustics and the estimation of their annihilation radiation in fully general
simulations of structure formation.Comment: 6 pages, 1 figure, Accepted for publication in MNRAS, minor edit
Schur functions and their realizations in the slice hyperholomorphic setting
we start the study of Schur analysis in the quaternionic setting using the
theory of slice hyperholomorphic functions. The novelty of our approach is that
slice hyperholomorphic functions allows to write realizations in terms of a
suitable resolvent, the so called S-resolvent operator and to extend several
results that hold in the complex case to the quaternionic case. We discuss
reproducing kernels, positive definite functions in this setting and we show
how they can be obtained in our setting using the extension operator and the
slice regular product. We define Schur multipliers, and find their co-isometric
realization in terms of the associated de Branges-Rovnyak space
Dark Energy and Extending the Geodesic Equations of Motion: Connecting the Galactic and Cosmological Length Scales
Recently, an extension of the geodesic equations of motion using the Dark
Energy length scale was proposed. Here, we apply this extension to the
analyzing the motion of test particles at the galactic scale and longer. A
cosmological check of the extension is made using the observed rotational
velocity curves and core sizes of 1393 spiral galaxies. We derive the density
profile of a model galaxy using this extension, and with it, we calculate
to be ; this is within experimental error of the
WMAP value of . We then calculate to be
kpc, which is in reasonable agreement with observations.Comment: 25 pages. Accepted for publication in General Relativity and
Gravitation. Paper contains the published version of the second half of
arXiv:0711.3124v2 with corrections include
Nonspherical similarity solutions for dark halo formation
We carry out fully 3-dimensional simulations of evolution from self-similar,
spherically symmetric linear perturbations of a Cold Dark Matter dominated
Einstein-de Sitter universe. As a result of the radial orbit instability, the
haloes which grow from such initial conditions are triaxial with major-to-minor
axis ratios of order 3:1. They nevertheless grow approximately self-similarly
in time. In all cases they have power-law density profiles and near-constant
velocity anisotropy in their inner regions. Both the power-law index and the
value of the velocity anisotropy depend on the similarity index of the initial
conditions, the former as expected from simple scaling arguments. Halo
structure is thus not "universal" but remembers the initial conditions. On
larger scales the density and anisotropy profiles show two characteristic
scales, corresponding to particles at first pericentre and at first apocentre
after infall. They are well approximated by the NFW model only for one value of
the similarity index. In contrast, at all radii within the outer caustic the
pseudo phase-space density can be fit by a single power law with an index which
depends only very weakly on the similarity index of the initial conditions.
This behaviour is very similar to that found for haloes formed from LCDM
initial conditions and so can be considered approximately universal.Comment: 8 pages, 7 figures, submitted to MNRA
Evaluating policy as argument: the public debate over the first UK austerity budget
This article aims to make a methodological contribution to the ‘argumentative turn’ in policy analysis and to the understanding of the public debate on the UK Government's austerity policies. It suggests that policy arguments are practical arguments from circumstances, goals and means–goal relations to practical conclusions (proposals) that can ground decision and action. Practical proposals are evaluated in light of their potential consequences. This article proposes a deliberation scheme and a set of critical questions for the evaluation of deliberation and decision-making in conditions of incomplete knowledge (uncertainty and risk). It illustrates these questions by analysing a corpus of articles from five newspapers over the two months following the adoption of the first austerity budget in June 2010. It also suggests how analysis of ‘frames’ and ‘framing’ can be integrated with the evaluation of deliberation and decision-making
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