3,811 research outputs found
The Eroding Artificial/Natural Distinction: Some Consequences for Ecology and Economics
Since Thomas Kuhnâs The Structure of Scientific Revolutions (1962), historians and philosophers of science have paid increasing attention to the implications of disciplinarity. In this chapter we consider restrictions posed to interdisciplinary exchange between ecology and economics that result from a particular kind of commitment to the ideal of disciplinary purity, that is, that each discipline is defined by an appropriate, unique set of objects, methods, theories, and aims. We argue that, when it comes to the objects of study in ecology and economics, ideas of disciplinary purity have been underwritten by the artificial-natural distinction. We then problematize this distinction, and thus disciplinary purity, both conceptually and empirically. Conceptually, the distinction is no longer tenable. Empirically, recent interdisciplinary research has shown the epistemological and policy-oriented benefits of dealing with models which explicitly link anthropogenic (i.e., âartificialâ) and non-anthropogenic factors (i.e., ânaturalâ). We conclude that, in the current age of the Anthropocene, it is to be expected that without interdisciplinary exchange, ecology and economics may relinquish global relevance because the distinct and separate systems to which each âpureâ science was originally made to apply will only diminish over time
Wild cyclic-by-tame extensions
Suppose G is a semi-direct product of the form Z/p^n \rtimes Z/m where p is
prime and m is relatively prime to p. Suppose K is a local field of
characteristic p > 0. The main result states necessary and sufficient
conditions on the ramification filtrations that occur for wildly ramified
G-Galois extensions of K. In addition, we prove that there exists a parameter
space for G-Galois extensions of K with given ramification filtration whose
dimension depends only on the ramification filtration. We provide explicit
equations for wild cyclic extensions of K of degree p^3.Comment: 15 pages, section 6.2 eliminated, major simplifications in former
Proposition 4.3 (now Proposition 4.2), corrections in former Proposition 4.4
(now Proposition 4.3), many small changes in notations and languag
Organic Farming in Wales 2003 - 2004
Organic Centre Wales (OCW) was originally formed to act as an information source for producers enquiring into organic farming; in our second phase, in response to changes in the sector, we have an increased remit on policy issues. It has been a busy time, seeing the production of a second Organic Action Plan, the implementation of the CAP reform and development work on agri-environment reforms. The year also saw the start of organic maintenance payments for farmers.
This Annual Report contains accounts of the progress that has been made on many fronts during the last 12 months, particularly in market knowledge due to the research for the recently published report, 'Organic Food: understanding the consumer and increasing sales'. This information, together with continuing product development work, will enable Welsh organic producers to be proactive in building a solid consumer base
Give us a game : evaluating the opportunities that exist for English footballers to play in the English Premier League
The purpose of this study was to provide a detailed, large-scale retrospective analysis of the number of English footballers that have been developed to play in the English Premier League (EPL) over twenty seasons. Unlike previous research, we examined appearance data as opposed to percentage of squad data enabling a more accurate representation of English players appearing in the EPL. The findings revealed a steady decline in the number and proportion of appearances made by English players in the EPL throughout the twenty season period. However, the results also indicated that the rate of decline had abated since the inception of UEFA's home-grown rule. The results support the view that opportunities for indigenous players have diminished since the EPL's inception. Given the short-term, results-focused culture that prevails in the EPL, this would appear to present a major challenge for governing bodies, particularly those working in elite player development. Discussion surrounding how these challenges might be met is presented
2006 SQ372: A Likely Long-Period Comet from the Inner Oort Cloud
We report the discovery of a minor planet (2006 SQ372) on an orbit with a
perihelion of 24 AU and a semimajor axis of 796 AU. Dynamical simulations show
that this is a transient orbit and is unstable on a timescale of 200 Myrs.
Falling near the upper semimajor axis range of the scattered disk and the lower
semimajor axis range of the Oort Cloud, previous membership in either class is
possible. By modeling the production of similar orbits from the Oort Cloud as
well as from the scattered disk, we find that the Oort Cloud produces 16 times
as many objects on SQ372-like orbits as the scattered disk. Given this result,
we believe this to be the most distant long-period comet ever discovered.
Furthermore, our simulation results also indicate that 2000 OO67 has had a
similar dynamical history. Unaffected by the "Jupiter-Saturn Barrier," these
two objects are most likely long-period comets from the inner Oort Cloud
Causality and the semantics of provenance
Provenance, or information about the sources, derivation, custody or history
of data, has been studied recently in a number of contexts, including
databases, scientific workflows and the Semantic Web. Many provenance
mechanisms have been developed, motivated by informal notions such as
influence, dependence, explanation and causality. However, there has been
little study of whether these mechanisms formally satisfy appropriate policies
or even how to formalize relevant motivating concepts such as causality. We
contend that mathematical models of these concepts are needed to justify and
compare provenance techniques. In this paper we review a theory of causality
based on structural models that has been developed in artificial intelligence,
and describe work in progress on a causal semantics for provenance graphs.Comment: Workshop submissio
Pre-Impact Thermophysical Properties and the Yarkovsky Effect of NASA DART Target (65803) Didymos
The NASA DART (Double Asteroid Redirection Test) spacecraft impacted the secondary body of the binary asteroid (65803) Didymos on 2022 September 26and altered its orbit about the primary body. Before the DART impact, we performed visible and mid-infrared observations to constrain the pre-impact thermophysical properties of the Didymos system and to model its Yarkovsky effect. Analysis of the photometric phase curve derives a Bond albedo of 0.07 ± 0.01, and a thermophysical analysis of the mid-infrared observations derives a thermal inertia of 320 ± 70 J m-2 K-1 s-1/2 and a thermal roughness of 40° ± 3° RMS (root-mean-square) slope. These properties are compatible with the ranges derived for other S-type near-Earth asteroids. Model-to-measurement comparisons of the Yarkovsky orbital drift for Didymos derives a bulk density of 2750 ± 350 kg m-3, which agrees with other independent measures based on the binary mutual orbit. This bulk density indicates that Didymos is spinning at or near its critical spin-limit at which self-gravity balances equatorial centrifugal forces. Furthermore, comparisons with the post-impact infrared observations presented in Rivkin et al. (2023) indicate no change in the thermal inertia of the Didymos system following the DART impact. Finally, orbital temperature simulations indicate that sub-surface water ice is stable over geologic timescales in the polar regions if present. These findings will be investigated in more detail by the upcoming ESA Hera mission.<br/
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