6,653 research outputs found
FORECASTING FUTURE EMPLOYMENT OPPORTUNITIES FOR FOOD, AGRICULTURE, AND NATURAL RESOURCES HIGHER EDUCATION GRADUATES USING ADJUSTED BUREAU OF LABOR FORECASTS
Forecasts of the number of future professionals required for an ongoing safe, efficient US food system are highly important. The demand for adequately prepared higher education graduates must be met by the US Food, Agriculture, and Natural Resources Education System. Without accurate forecasts of the human resource needs of the food sector of the economy, adequate professionals may not be available when needed. This research effort makes use of Bureau of Labor Statistics (BLS) forecasted employment opportunities. The estimation of professionals required in the food and agriculture sectors of the economy is developed by selecting and manipulating data from the BLS model that is relevant to food and agriculture careers. These forecasts of needed professionals can be used by Directors of Resident Instruction to manage the educational system to meet the food sector demands for adequately educated human resources.employment, employment opportunities, food, agriculture, natural resources, directed graphs, education, bureau of labor, Labor and Human Capital,
Stability of global entanglement in thermal states of spin chains
We investigate the entanglement properties of a one dimensional chain of spin
qubits coupled via nearest neighbor interactions. The entanglement measure used
is the n-concurrence, which is distinct from other measures on spin chains such
as bipartite entanglement in that it can quantify "global" entanglement across
the spin chain. Specifically, it computes the overlap of a quantum state with
its time-reversed state. As such this measure is well suited to study ground
states of spin chain Hamiltonians that are intrinsically time reversal
symmetric. We study the robustness of n-concurrence of ground states when the
interaction is subject to a time reversal antisymmetric magnetic field
perturbation. The n-concurrence in the ground state of the isotropic XX model
is computed and it is shown that there is a critical magnetic field strength at
which the entanglement experiences a jump discontinuity from the maximum value
to zero. The n-concurrence for thermal mixed states is derived and a threshold
temperature is computed below which the system has non zero entanglement.Comment: 13 pages, 3 figures. v.2 includes minor corrections and an added
section treating the quantum XX model with open boundarie
Criminal benefit, the confiscation order and the post-conviction confiscation regime
Governments and law enforcement agencies around the world seek to identify and confiscate the 'proceeds of crime' on the assertion that doing so will deter offending and symbolise to citizens and communities that 'crime does not pay'. In the UK such assertions have underpinned the enactment of legislation, the investment in law enforcement agents and the development of wide ranging new technologies to facilitate the identification of assets and their recovery. This paper critically considers two key concepts which fundamentally drive the post-conviction confiscation regime in the UK. First, 'criminal benefit' which is the amount that a defendant is adjudged to have made from 'criminal conduct'. Second, the 'available amount' which is the amount that the state hopes to recover from a defendant via the court ordered 'confiscation order'. In so doing, this paper explores the assumptions at the heart of the 2002 Proceeds of Crime Act and their application in practice, concentrating on the nature of the powers accorded to financial investigators and how these powers have been interpreted and applied. It is argued that far from representing the 'profit' generated from crime these values are constructs founded in the relationship between legislation, the discretional practice of police officers and financial investigators, organisational restrictions and constraints and informal negotiation and compromise between the defence and prosecution. This has implications for both conceptualising the nature of the post-conviction confiscation regime as well as for shaping what the state might expect to recover from defendants. © 2014 Springer Science+Business Media Dordrecht
Theory of Effectiveness Measurement
Effectiveness measures provide decision makers feedback on the impact of deliberate actions and affect critical issues such as allocation of scarce resources, as well as whether to maintain or change existing strategy. Currently, however, there is no formal foundation for formulating effectiveness measures. This research presents a new framework for effectiveness measurement from both a theoretical and practical view. First, accepted effects-based principles, as well as fundamental measurement concepts are combined into a general, domain independent, effectiveness measurement methodology. This is accomplished by defining effectiveness measurement as the difference, or conceptual distance from a given system state to some reference system state (e.g. desired end-state). Then, by developing system attribute measures such that they yield a system state-space that can be characterized as a metric space, differences in system states relative to the reference state can be gauged over time, yielding a generalized, axiomatic definition of effectiveness measurement. The effectiveness measurement framework is then extended to mitigate the influence of measurement error and uncertainty by employing Kalman filtering techniques. Finally, the pragmatic nature of the approach is illustrated by measuring the effectiveness of a notional, security force response strategy in a scenario involving a terrorist attack on a United States Air Force base
Can the mid-Holocene provide suitable models for rewilding the landscape in Britain?
Palaeoecologists have been encouraging us to think about the relevance of the Holocene fossil record for nature conservation for many years (e.g. Buckland 1993) but this information seems slow to filter through to the conservation community. Indeed, Willis et al. (2005) report
that recently published biodiversity reports and policy documents rarely look back more than 50 years and may ignore the historical context entirely. This has been a lost opportunity for understanding ecological systems. Many natural processes occur over timescales that confound our attempts to understand them, so the vast temporal
perspective provided by palaeoecological studies
can provide important guidance for nature conservation
(Willis & Birks 2006).
However, accurate vegetation mapping is difficult enough in modern landscapes (Cherrill & McLean 1999), so the challenge of describing prehistoric environments is immeasurably greater.
Nevertheless, pioneering work in the mid 20th century showed that pollen and spores extracted from peat bogs were so perfectly preserved thatthey could be used to demonstrate sequences of vegetation change since the last glaciation
(Godwin 1956). Since then, the science has
burgeoned: ancient deposits of beetles, snails,
fungal spores and plant macrofossils add to the
picture, as does the chemistry of ancient lake sediments
(Bell & Walker 2004).
Many questions still remain to be answered by this fascinating research and one aspect has received considerable attention in the last decade.
This concerns the nature of the ‘primeval’ landscapes,
in other words our understanding of natural systems prior to significant human impact. The debate was kindled by a thesis by the Dutch forest ecologist Frans Vera in 2000 (see also Vera & Buissink 2007). Vera effectively challenged established views about the primeval landscapes and argued that the refutation, and the resulting alternative landscape models, had critical importance
for modern conservation practice.
Vera’s thesis is focused on the pre-Neolithic (ca 8000-5000bp) landscape in the lowlands of central and western Europe, with the assumption that this period represents an almost pristine or ‘natural’ state which should provide a suitable conservation benchmark. Vera contends (i) that
this landscape was not closed woodland but a relatively
open park-like mosaic of wood and grassland,and (ii) that large wild herbivores were an essential driving force behind woodland-grassland vegetation cycles. The advocacy in his argument and the timing of the publication, when grazingwas seen as increasingly important in conservation
in Europe, have combined to raise the profile
of this issue. If Vera is correct, the open park-like
landscapes were inherited rather than created by
people; this may have implications for conservation
practice in Europe.
The adoption of Vera’s ideas into conservation
management plans in the UK (see Box 1) gives an
indication of the influence that this work has had.
Indeed, Vera’s ideas have been described as a ‘challenge
to orthodox thinking’ (Miller 2002) and considerable debate has been stimulated centering
on the ecological validity of Vera’s hypothesis
and its relevance for modern conservation.
In this article, we attempt to address these issues
on the basis of results from a literature review,
web-debate and discussions with Dutch and British
ecologists, prepared for English Nature with a
view to informing conservation strategies (Hodder
& Bullock 2005a)
Time Reversal and n-qubit Canonical Decompositions
For n an even number of qubits and v a unitary evolution, a matrix
decomposition v=k1 a k2 of the unitary group is explicitly computable and
allows for study of the dynamics of the concurrence entanglement monotone. The
side factors k1 and k2 of this Concurrence Canonical Decomposition (CCD) are
concurrence symmetries, so the dynamics reduce to consideration of the a
factor. In this work, we provide an explicit numerical algorithm computing v=k1
a k2 for n odd. Further, in the odd case we lift the monotone to a two-argument
function, allowing for a theory of concurrence dynamics in odd qubits. The
generalization may also be studied using the CCD, leading again to maximal
concurrence capacity for most unitaries. The key technique is to consider the
spin-flip as a time reversal symmetry operator in Wigner's axiomatization; the
original CCD derivation may be restated entirely in terms of this time
reversal. En route, we observe a Kramers' nondegeneracy: the existence of a
nondegenerate eigenstate of any time reversal symmetric n-qubit Hamiltonian
demands (i) n even and (ii) maximal concurrence of said eigenstate. We provide
examples of how to apply this work to study the kinematics and dynamics of
entanglement in spin chain Hamiltonians.Comment: 20 pages, 3 figures; v2 (17pp.): major revision, new abstract,
introduction, expanded bibliograph
An ion probe study of the sulphur isotopic composition of Fe-Ni sulphides in CM carbonaceous chondrites
From the Introduction: The CM chondrites have endured variable degrees of aqueous alteration [1] which has changed their original mineralogy. A detailed study of the petrology and mineralogy of the sulphides in a suite of increasingly aqueously altered CMs, combined with sulphur isotope data measured in situ, can provide clues as to whether differences in the CM group are a result of different degrees of aqueous alteration, or whether they are the result of nebular heterogeneity
Parallelism for Quantum Computation with Qudits
Robust quantum computation with d-level quantum systems (qudits) poses two
requirements: fast, parallel quantum gates and high fidelity two-qudit gates.
We first describe how to implement parallel single qudit operations. It is by
now well known that any single-qudit unitary can be decomposed into a sequence
of Givens rotations on two-dimensional subspaces of the qudit state space.
Using a coupling graph to represent physically allowed couplings between pairs
of qudit states, we then show that the logical depth of the parallel gate
sequence is equal to the height of an associated tree. The implementation of a
given unitary can then optimize the tradeoff between gate time and resources
used. These ideas are illustrated for qudits encoded in the ground hyperfine
states of the atomic alkalies Rb and Cs. Second, we provide a
protocol for implementing parallelized non-local two-qudit gates using the
assistance of entangled qubit pairs. Because the entangled qubits can be
prepared non-deterministically, this offers the possibility of high fidelity
two-qudit gates.Comment: 9 pages, 3 figure
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