837 research outputs found
On Perturbations of Unitary Minimal Models by Boundary Condition Changing Operators
In this note we consider boundary perturbations in the A-Series unitary
minimal models by phi_{r,r+2} fields on superpositions of boundaries. In
particular, we consider perturbations by boundary condition changing operators.
Within conformal perturbation theory we explicitly map out the space of
perturbative renormalisation group flows for the example phi_{1,3} and find
that this sheds light on more general phi_{r,r+2} perturbations. Finally, we
find a simple diagrammatic representation for the space of flows from a single
Cardy boundary condition.Comment: 27 pages, 10 figure
Political Communication in the Online Era: Moral Psychology of News Media Consumption, New Forms of News Media, and Political Communication
Drawing on data from the moral psychology of political communication and literature on news media consumption, this thesis explores the relationships between new forms of news media and longstanding trends in the moral psychology of political communication. By discussing dynamic changes in the form and content of news media, as well as the new venues through which it is experienced, this thesis highlights three areas in which new forms of media place pressure on existing literature. Namely, it holds that the ways in which individuals experience new forms of news media place pressure on existing literature centering around the homogeneity of political discussion networks, the transmission of political expertise, and the credibility of news media. The implications of these pressures are numerous and multiply caused, and impel policymakers to take seriously questions concerning the regulation of news media content
Rural living and health-related quality of life in Australians with Parkinson\u27s disease
Introduction: The motor and non-motor symptoms associated with idiopathic Parkinson’s disease (PD) may compromise the health-related quality of life (HRQOL) of some individuals living with this debilitating condition. Although growing evidence suggests that PD may be more prevalent in rural communities, there is little information about the life quality of these individuals. This study examines whether HRQOL ratings vary in relation to rural and metropolitan life settings. Methods: An analytic cross-sectional study was conducted to compare the HRQOL of two separate samples of people with PD living in metropolitan Melbourne and rural Victoria. The metropolitan sample consisted of 210 individuals who had participated in the baseline assessment for an existing clinical trial. The rural sample comprised 24 participants who attended community-based rehabilitation programs and support groups in rural Victoria. Health-related quality of life was quantified using the Parkinson’s Disease Questionnaire-39 (PDQ-39). Results: The HRQOL of participants in rural Australia differed from individuals living in a large metropolitan city (p=0.025). Participants in rural Australia reported worse overall HRQOL, after controlling for differences in disease duration. Their overall HRQOL was lower than for city dwellers. Rural living was also found to be a significant negative predictor of HRQOL (β=0.14; 95% CI -1.27 to -0.08; p=0.027).Conclusion: The findings of this study suggest that some people with PD living in rural Victoria perceive their HRQOL to be relatively poor. In order to minimise the debilitating consequences of this disease, further studies examining the factors that may contribute to the HRQOL of individuals living in rural and remote areas are required
Universality of the Crossing Probability for the Potts Model for q=1,2,3,4
The universality of the crossing probability of a system to
percolate only in the horizontal direction, was investigated numerically by
using a cluster Monte-Carlo algorithm for the -state Potts model for
and for percolation . We check the percolation through
Fortuin-Kasteleyn clusters near the critical point on the square lattice by
using representation of the Potts model as the correlated site-bond percolation
model. It was shown that probability of a system to percolate only in the
horizontal direction has universal form for
as a function of the scaling variable . Here,
is the probability of a bond to be closed, is the
nonuniversal crossing amplitude, is the nonuniversal metric factor,
is the nonuniversal scaling index, is the correlation
length index.
The universal function . Nonuniversal scaling factors
were found numerically.Comment: 15 pages, 3 figures, revtex4b, (minor errors in text fixed,
journal-ref added
Portland cement based immobilization/destruction of chemical weapon agent degradation products
The direct immobilization and destruction of two compounds relevant to chemical warfare agents, ethyl methylphosphonic acid (EMPA) and thiodiglycol (TDG), within a freshly mixed Portland cement paste was studied. Cement hydration and phase formation were analyzed to determine the upper limits on the loading of these chemicals achievable in an immobilization setting. EMPA, a degradation product of the nerve agent VX, alters the phase formation within the cements, allowing calcium aluminate dissolution while retarding hydration of calcium silicate clinker phases. This yielded ettringite, and sufficient calcium silicate hydrate for setting at 10 wt % loading, but the cohesive calcium silicate binding phase was lacking when EMPA was added at 25 wt %. The addition of TDG, a degradation product of sulfur mustard, uniformly retards the entire range of cement hydration mechanisms. Heat output was lowered and extended over a longer time frame, and less strength forming phases were produced. Up to 10% wt. TDG could be accommodated by the cement, but higher loadings caused severe disruption to the cement setting. This work demonstrates the ability of Portland cement to directly incorporate up to 10% wt. of these contaminants, and still form a stable set cement with conventional hydration phases
Shortest paths on systems with power-law distributed long-range connections
We discuss shortest-path lengths on periodic rings of size L
supplemented with an average of pL randomly located long-range links whose
lengths are distributed according to P_l \sim l^{-\xpn}. Using rescaling
arguments and numerical simulation on systems of up to sites, we show
that a characteristic length exists such that for
. For small p we find
that the shortest-path length satisfies the scaling relation
\ell(r,\xpn,p)/\xi = f(\xpn,r/\xi). Three regions with different asymptotic
behaviors are found, respectively: a) \xpn>2 where , b)
1<\xpn<2 where 0<\theta_s(\xpn)<1/2 and, c) \xpn<1 where
behaves logarithmically, i.e. . The characteristic length is
of the form with \nu=1/(2-\xpn) in region b), but depends
on L as well in region c). A directed model of shortest-paths is solved and
compared with numerical results.Comment: 10 pages, 10 figures, revtex4. Submitted to PR
An algorithm to discover the k-clique cover in networks
In social network analysis, a k-clique is a relaxed clique, i.e., a k-clique is a quasi-complete sub-graph. A k-clique in a graph is a sub-graph where the distance between any two vertices is no greater than k. The
visualization of a small number of vertices can be easily performed in a graph.
However, when the number of vertices and edges increases the visualization
becomes incomprehensible. In this paper, we propose a new graph mining approach based on k-cliques. The concept of relaxed clique is extended to the whole graph, to achieve a general view, by covering the network with k-cliques.
The sequence of k-clique covers is presented, combining small world concepts
with community structure components. Computational results and examples are
presented
Extended multiplet structure in Logarithmic Conformal Field Theories
We use the process of quantum hamiltonian reduction of SU(2)_k, at rational
level k, to study explicitly the correlators of the h_{1,s} fields in the
c_{p,q} models. We find from direct calculation of the correlators that we have
the possibility of extra, chiral and non-chiral, multiplet structure in the
h_{1,s} operators beyond the `minimal' sector. At the level of the vacuum null
vector h_{1,2p-1}=(p-1)(q-1) we find that there can be two extra non-chiral
fermionic fields. The extra indicial structure present here permeates
throughout the entire theory. In particular we find we have a chiral triplet of
fields at h_{1,4p-1}=(2p-1)(2q-1). We conjecture that this triplet algebra may
produce a rational extended c_{p,q} model. We also find a doublet of fields at
h_{1,3p-1}=(\f{3p}{2}-1)(\f{3q}{2}-1). These are chiral fermionic operators if
p and q are not both odd and otherwise parafermionic.Comment: 24 pages LATEX. Minor corrections and extra reference
Dynamics in online social networks
An increasing number of today's social interactions occurs using online
social media as communication channels. Some online social networks have become
extremely popular in the last decade. They differ among themselves in the
character of the service they provide to online users. For instance, Facebook
can be seen mainly as a platform for keeping in touch with close friends and
relatives, Twitter is used to propagate and receive news, LinkedIn facilitates
the maintenance of professional contacts, Flickr gathers amateurs and
professionals of photography, etc. Albeit different, all these online platforms
share an ingredient that pervades all their applications. There exists an
underlying social network that allows their users to keep in touch with each
other and helps to engage them in common activities or interactions leading to
a better fulfillment of the service's purposes. This is the reason why these
platforms share a good number of functionalities, e.g., personal communication
channels, broadcasted status updates, easy one-step information sharing, news
feeds exposing broadcasted content, etc. As a result, online social networks
are an interesting field to study an online social behavior that seems to be
generic among the different online services. Since at the bottom of these
services lays a network of declared relations and the basic interactions in
these platforms tend to be pairwise, a natural methodology for studying these
systems is provided by network science. In this chapter we describe some of the
results of research studies on the structure, dynamics and social activity in
online social networks. We present them in the interdisciplinary context of
network science, sociological studies and computer science.Comment: 17 pages, 4 figures, book chapte
Identification of Candida species isolated from cows suffering mastitis in four Brazilian states
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