2,382 research outputs found
Fair game: exploring the dynamics, perception and environmental impact of ‘surplus’ wild foods in England 10kya-present
This paper brings together zooarchaeological data from Neolithic to Post-medieval sites in England to explore the plasticity of cultural attitudes to the consumption of wild animals. It shows how, through time, game has been considered variously as ‘tabooed’ and ‘edible’, each having implications for patterns of biodiversity and wildlife management. The essential points being made are that deeper-time studies can reveal how human perceptions of ‘surplus foods’ have the potential to both create and remedy problems of environmental sustainability and food security. Perhaps more significantly, this paper argues that understanding the bio-cultural past of edible wild animal species has the potential to transform human attitudes to game in the present. This is important at a time when food security and the production of surplus are pressing national and global concerns
Pre-conceptual Design Assessment of DEMO Remote Maintenance
EDFA, as part of the Power Plant Physics and Technology programme, has been
working on the pre-conceptual design of a Demonstration Power Plant (DEMO). As
part of this programme, a review of the remote maintenance strategy considered
maintenance solutions compatible with expected environmental conditions, whilst
showing potential for meeting the plant availability targets. A key finding was
that, for practical purposes, the expected radiation levels prohibit the use of
complex remote handling operations to replace the first wall. In 2012/13, these
remote maintenance activities were further extended, providing an insight into
the requirements, constraints and challenges. In particular, the assessment of
blanket and divertor maintenance, in light of the expected radiation conditions
and availability, has elaborated the need for a very different approach from
that of ITER. This activity has produced some very informative virtual reality
simulations of the blanket segments and pipe removal that are exceptionally
valuable in communicating the complexity and scale of the required operations.
Through these simulations, estimates of the maintenance task durations have
been possible demonstrating that a full replacement of the blankets within 6
months could be achieved. The design of the first wall, including the need to
use sacrificial limiters must still be investigated. In support of the
maintenance operations, a first indication of the requirements of an Active
Maintenance Facility (AMF) has been elaborated.Comment: 6 pages, 5 figure
From icon of empire to national emblem: new evidence for the fallow deer of Barbuda
Barbuda and Antigua's national animal is the fallow deer, Dama dama dama, a species native to the eastern Mediterranean that has been transported around the world by people during the last 8,000 years. The timing and circumstances by which fallow deer came to be established on Barbuda are currently uncertain but, by examining documentary, osteological and genetic evidence, this paper will consider the validity of existing theories. It will review the dynamics of human-Dama relationships from the 1500s AD to the present day and consider how the meaning attached to this species has changed through time: from a symbol of colonial authority and dominance, to a 'walking larder' after the slave emancipation of 1834, and now an important part of the island's economy and cultural heritage that requires careful management
Minimal Model for Sand Dunes
We propose a minimal model for aeolian sand dunes. It combines an analytical
description of the turbulent wind velocity field above the dune with a
continuum saltation model that allows for saturation transients in the sand
flux. The model provides a qualitative understanding of important features of
real dunes, such as their longitudinal shape and aspect ratio, the formation of
a slip face, the breaking of scale invariance, and the existence of a minimum
dune size.Comment: 4 pages, 4 figures, replaced with publishd versio
Dynamics of the attractive 1D Bose gas: analytical treatment from integrability
The physics of the attractive one-dimensional Bose gas (Lieb-Liniger model)
is investigated with techniques based on the integrability of the system.
Combining a knowledge of particle quasi-momenta to exponential precision in the
system size with determinant representations of matrix elements of local
operators coming from the Algebraic Bethe Ansatz, we obtain rather general
analytical results for the zero-temperature dynamical correlation functions of
the density and field operators. Our results thus provide quantitative
predictions for possible future experiments in atomic gases or optical
waveguides.Comment: 26 pages, 5 figure
Theory of superfluidity and drag force in the one-dimensional Bose gas
The one-dimensional Bose gas is an unusual superfluid. In contrast to higher
spatial dimensions, the existence of non-classical rotational inertia is not
directly linked to the dissipationless motion of infinitesimal impurities.
Recently, experimental tests with ultracold atoms have begun and quantitative
predictions for the drag force experienced by moving obstacles have become
available. This topical review discusses the drag force obtained from linear
response theory in relation to Landau's criterion of superfluidity. Based upon
improved analytical and numerical understanding of the dynamical structure
factor, results for different obstacle potentials are obtained, including
single impurities, optical lattices and random potentials generated from
speckle patterns. The dynamical breakdown of superfluidity in random potentials
is discussed in relation to Anderson localization and the predicted
superfluid-insulator transition in these systems.Comment: 17 pages, 12 figures, mini-review prepared for the special issue of
Frontiers of Physics "Recent Progresses on Quantum Dynamics of Ultracold
Atoms and Future Quantum Technologies", edited by Profs. Lee, Ueda, and
Drummon
Increased nuclear suppressor of cytokine signaling 1 in asthmatic bronchial epithelium suppresses rhinovirus induction of innate interferons
Background Rhinovirus infections are the dominant cause of asthma exacerbations, and deficient virus induction of IFN-α/β/λ in asthmatic patients is important in asthma exacerbation pathogenesis. Mechanisms causing this interferon deficiency in asthmatic patients are unknown. Objective We sought to investigate the expression of suppressor of cytokine signaling (SOCS) 1 in tissues from asthmatic patients and its possible role in impaired virus-induced interferon induction in these patients. Methods We assessed SOCS1 mRNA and protein levels in vitro, bronchial biopsy specimens, and mice. The role of SOCS1 was inferred by proof-of-concept studies using overexpression with reporter genes and SOCS1-deficient mice. A nuclear role of SOCS1 was shown by using bronchial biopsy staining, overexpression of mutant SOCS1 constructs, and confocal microscopy. SOCS1 levels were also correlated with asthma-related clinical outcomes. Results We report induction of SOCS1 in bronchial epithelial cells (BECs) by asthma exacerbation–related cytokines and by rhinovirus infection in vitro. We found that SOCS1 was increased in vivo in bronchial epithelium and related to asthma severity. SOCS1 expression was also increased in primary BECs from asthmatic patients ex vivo and was related to interferon deficiency and increased viral replication. In primary human epithelium, mouse lung macrophages, and SOCS1-deficient mice, SOCS1 suppressed rhinovirus induction of interferons. Suppression of virus-induced interferon levels was dependent on SOCS1 nuclear translocation but independent of proteasomal degradation of transcription factors. Nuclear SOCS1 levels were also increased in BECs from asthmatic patients. Conclusion We describe a novel mechanism explaining interferon deficiency in asthmatic patients through a novel nuclear function of SOCS1 and identify SOCS1 as an important therapeutic target for asthma exacerbations
Field evidence for the upwind velocity shift at the crest of low dunes
Wind topographically forced by hills and sand dunes accelerates on the upwind
(stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind
regime, however, possesses a subtle effect, reported here for the first time
from field measurements of near-surface wind velocity over a low dune: the wind
velocity close to the surface reaches its maximum upwind of the crest. Our
field-measured data show that this upwind phase shift of velocity with respect
to topography is found to be in quantitative agreement with the prediction of
hydrodynamical linear analysis for turbulent flows with first order closures.
This effect, together with sand transport spatial relaxation, is at the origin
of the mechanisms of dune initiation, instability and growth.Comment: 13 pages, 6 figures. Version accepted for publication in
Boundary-Layer Meteorolog
- …