2,160 research outputs found
Building Global Citizenship through Network Leadership
This article is based upon a paper delivered by Anne Beales about the Interrelate group to the International Initiative for Mental Health Leadership, IIMHL, Conference in Killarney, Ireland, May 2010, and developed by the Interrelate group: Daniel Fisher, US, Shaun McNeil, Scotland, Jenny Speed, Australia, Paddy MacGowan, Ireland, Gary Platz, New Zealand, and Joan Edwards-Karmazyn, Canada
Anaerobic Cultures from Preserved Tissues of Baby Mammoth
Microbiological analysis of several cold-preserved tissue samples from the Siberian baby mammoth known as Lyuba revealed a number of culturable bacterial strains that were grown on anaerobic media at 4 C. Lactic acid produced by LAB (lactic acid bacteria) group, usually by members of the genera Carnobacterium and Lactosphera, appears to be a wonderful preservative that prevents other bacteria from over-dominating a system. Permafrost and lactic acid preserved the body of this one-month old baby mammoth and kept it in exceptionally good condition, resulting in this mammoth being the most complete such specimen ever recovered. The diversity of novel anaerobic isolates was expressed on morphological, physiological and phylogenetic levels. Here we discuss the specifics of the isolation of new strains, differentiation from trivial contamination, and preliminary results for the characterization of cultures
Nonequilibrium dynamics of random field Ising spin chains: exact results via real space RG
Non-equilibrium dynamics of classical random Ising spin chains are studied
using asymptotically exact real space renormalization group. Specifically the
random field Ising model with and without an applied field (and the Ising spin
glass (SG) in a field), in the universal regime of a large Imry Ma length so
that coarsening of domains after a quench occurs over large scales. Two types
of domain walls diffuse in opposite Sinai random potentials and mutually
annihilate. The domain walls converge rapidly to a set of system-specific
time-dependent positions {\it independent of the initial conditions}. We obtain
the time dependent energy, magnetization and domain size distribution
(statistically independent). The equilibrium limits agree with known exact
results. We obtain exact scaling forms for two-point equal time correlation and
two-time autocorrelations. We also compute the persistence properties of a
single spin, of local magnetization, and of domains. The analogous quantities
for the spin glass are obtained. We compute the two-point two-time correlation
which can be measured by experiments on spin-glass like systems. Thermal
fluctuations are found to be dominated by rare events; all moments of truncated
correlations are computed. The response to a small field applied after waiting
time , as measured in aging experiments, and the fluctuation-dissipation
ratio are computed. For ,
, it equals its equilibrium value X=1, though time
translational invariance fails. It exhibits for aging regime
with non-trivial , different from mean field.Comment: 55 pages, 9 figures, revte
Depinning with dynamic stress overshoots: A hybrid of critical and pseudohysteretic behavior
A model of an elastic manifold driven through a random medium by an applied
force F is studied focussing on the effects of inertia and elastic waves, in
particular {\it stress overshoots} in which motion of one segment of the
manifold causes a temporary stress on its neighboring segments in addition to
the static stress. Such stress overshoots decrease the critical force for
depinning and make the depinning transition hysteretic. We find that the steady
state velocity of the moving phase is nevertheless history independent and the
critical behavior as the force is decreased is in the same universality class
as in the absence of stress overshoots: the dissipative limit which has been
studied analytically. To reach this conclusion, finite-size scaling analyses of
a variety of quantities have been supplemented by heuristic arguments.
If the force is increased slowly from zero, the spectrum of avalanche sizes
that occurs appears to be quite different from the dissipative limit. After
stopping from the moving phase, the restarting involves both fractal and
bubble-like nucleation. Hysteresis loops can be understood in terms of a
depletion layer caused by the stress overshoots, but surprisingly, in the limit
of very large samples the hysteresis loops vanish. We argue that, although
there can be striking differences over a wide range of length scales, the
universality class governing this pseudohysteresis is again that of the
dissipative limit. Consequences of this picture for the statistics and dynamics
of earthquakes on geological faults are briefly discussed.Comment: 43 pages, 57 figures (yes, that's a five followed by a seven), revte
From Relief to Recovery: Peer Support by Consumers Relieves the Traumas of Disasters and Facilitates Recovery from Mental Illness
This paper is about the expertise those with a lived experience of recovery from personal trauma can bring to disaster relief efforts in the form of peer support
Absence of Two-Dimensional Bragg Glasses
The stability to dislocations of the elastic phase, or ``Bragg glass'', of a
randomly pinned elastic medium in two dimensions is studied using the
minimum-cost-flow algorithm for a disordered fully-packed loop model. The
elastic phase is found to be unstable to dislocations due to the quenched
disorder. The energetics of dislocations are discussed within the framework of
renormalization group predictions as well as in terms of a domain wall picture.Comment: 5 pages, REVTEX, 3 figures included. Further information can be
obtained from [email protected]
Spatial distribution of shore-based fishers in the greater Perth Metropolitan area over summer 2010/2011
Aerial surveys are a useful technique for estimating numbers of recreational fishers. Following the success of a pilot study to examine the spatial patterns of recreational shore-based fishing activity in the Perth Metropolitan area from April – June 2010, another survey was conducted from December 2010 – February 2011 between Lancelin – Bunbury. More than 7,000 shorebased fishers were counted during 36 aerial flights, with significantly more recorded on morning and afternoon flights, when compared to those conducted at midday. Flights on weekends/public holidays also recorded more fishers than weekdays. The spatial distribution of fishers was variable along the coast, with sandy beaches at the northern and southern sections of the study area having high counts of fishers, along with groynes in the central section. Comparisons with the previous (autumn) study revealed that the northern beaches generally had higher numbers of shore-based fishers in summer, while those in the south had more during autumn. Data from this study assists with understanding the patterns of shore-based recreational fishing occurring along the greater Perth Metropolitan coast. Such information can be used to assist in the design of future on-ground surveys, compliance and education activities
Thermodynamic Casimir effects involving interacting field theories with zero modes
Systems with an O(n) symmetrical Hamiltonian are considered in a
-dimensional slab geometry of macroscopic lateral extension and finite
thickness that undergo a continuous bulk phase transition in the limit
. The effective forces induced by thermal fluctuations at and above
the bulk critical temperature (thermodynamic Casimir effect) are
investigated below the upper critical dimension by means of
field-theoretic renormalization group methods for the case of periodic and
special-special boundary conditions, where the latter correspond to the
critical enhancement of the surface interactions on both boundary planes. As
shown previously [\textit{Europhys. Lett.} \textbf{75}, 241 (2006)], the zero
modes that are present in Landau theory at make conventional
RG-improved perturbation theory in dimensions ill-defined. The
revised expansion introduced there is utilized to compute the scaling functions
of the excess free energy and the Casimir force for temperatures
T\geqT_{c,\infty} as functions of , where
is the bulk correlation length. Scaling functions of the
-dependent residual free energy per area are obtained whose
limits are in conformity with previous results for the Casimir amplitudes
to and display a more reasonable
small- behavior inasmuch as they approach the critical value
monotonically as .Comment: 23 pages, 10 figure
Bounding biomass in the Fisher equation
The FKPP equation with a variable growth rate and advection by an
incompressible velocity field is considered as a model for plankton dispersed
by ocean currents. If the average growth rate is negative then the model has a
survival-extinction transition; the location of this transition in the
parameter space is constrained using variational arguments and delimited by
simulations. The statistical steady state reached when the system is in the
survival region of parameter space is characterized by integral constraints and
upper and lower bounds on the biomass and productivity that follow from
variational arguments and direct inequalities. In the limit of
zero-decorrelation time the velocity field is shown to act as Fickian diffusion
with an eddy diffusivity much larger than the molecular diffusivity and this
allows a one-dimensional model to predict the biomass, productivity and
extinction transitions. All results are illustrated with a simple growth and
stirring model.Comment: 32 Pages, 13 Figure
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