301 research outputs found
QUALITY OF LIFE IN PATIENTS WITH BACK PAIN
The article presents data on the effect of pain syndrome in patients with dorsopathies on the quality of their life. Back pain is an actual problem of modern medicine. In 82-95 % of cases back pain is caused by dorsopathies. Chronic dorsopathies restrict patients' capacity for work, reduce quality of life, change minds and behavior. Therefore improvement of the quality of life of patients is an important aim of therapy. We studied the effect of back pain on the quality of life of patients with dorsopathy. To assess the quality of life we used non-specific questionnaire SF-36. This questionnaire allows to estimate "basic condition of the body", "physical functioning", "role functioning", "pain intensity", "social functioning", "emotional state", "life activity" and "mental health". The features of parameters of quality of life depending on the nature of pain in patients with dorsopathy were determined, the relationship between quality of life and the intensity of pain in patients with dorsopathy was showed as the result of the research
Temperature-driven single-valley Dirac fermions in HgTe quantum wells
We report on temperature-dependent magnetospectroscopy of two HgTe/CdHgTe
quantum wells below and above the critical well thickness . Our results,
obtained in magnetic fields up to 16 T and temperature range from 2 K to 150 K,
clearly indicate a change of the band-gap energy with temperature. The quantum
well wider than evidences a temperature-driven transition from
topological insulator to semiconductor phases. At the critical temperature of
90 K, the merging of inter- and intra-band transitions in weak magnetic fields
clearly specifies the formation of gapless state, revealing the appearance of
single-valley massless Dirac fermions with velocity of
ms. For both quantum wells, the energies extracted from
experimental data are in good agreement with calculations on the basis of the
8-band Kane Hamiltonian with temperature-dependent parameters.Comment: 5 pages, 3 figures and Supplemental Materials (4 pages
Majority versus minority dynamics: Phase transition in an interacting two-state spin system
We introduce a simple model of opinion dynamics in which binary-state agents
evolve due to the influence of agents in a local neighborhood. In a single
update step, a fixed-size group is defined and all agents in the group adopt
the state of the local majority with probability p or that of the local
minority with probability 1-p. For group size G=3, there is a phase transition
at p_c=2/3 in all spatial dimensions. For p>p_c, the global majority quickly
predominates, while for p<p_c, the system is driven to a mixed state in which
the densities of agents in each state are equal. For p=p_c, the average
magnetization (the difference in the density of agents in the two states) is
conserved and the system obeys classical voter model dynamics. In one dimension
and within a Kirkwood decoupling scheme, the final magnetization in a
finite-length system has a non-trivial dependence on the initial magnetization
for all p.ne.p_c, in agreement with numerical results. At p_c, the exact 2-spin
correlation functions decay algebraically toward the value 1 and the system
coarsens as in the classical voter model.Comment: 11 pages, 3 figures, revtex4 2-column format; minor revisions for
publication in PR
Dynamics of Social Balance on Networks
We study the evolution of social networks that contain both friendly and
unfriendly pairwise links between individual nodes. The network is endowed with
dynamics in which the sense of a link in an imbalanced triad--a triangular loop
with 1 or 3 unfriendly links--is reversed to make the triad balanced. With this
dynamics, an infinite network undergoes a dynamic phase transition from a
steady state to "paradise"--all links are friendly--as the propensity p for
friendly links in an update event passes through 1/2. A finite network always
falls into a socially-balanced absorbing state where no imbalanced triads
remain. If the additional constraint that the number of imbalanced triads in
the network does not increase in an update is imposed, then the network quickly
reaches a balanced final state.Comment: 10 pages, 7 figures, 2-column revtex4 forma
Particles Sliding on a Fluctuating Surface: Phase Separation and Power Laws
We study a system of hard-core particles sliding downwards on a fluctuating
one-dimensional surface which is characterized by a dynamical exponent . In
numerical simulations, an initially random particle density is found to coarsen
and obey scaling with a growing length scale . The structure
factor deviates from the Porod law in some cases. The steady state is unusual
in that the density-segregation order parameter shows strong fluctuations. The
two-point correlation function has a scaling form with a cusp at small argument
which we relate to a power law distribution of particle cluster sizes. Exact
results on a related model of surface depths provides insight into the origin
of this behaviour.Comment: 5 pages, 5 Postscript figure
Massless Dirac fermions in III-V semiconductor quantum wells
We report on the clear evidence of massless Dirac fermions in two-dimensional
system based on III-V semiconductors. Using a gated Hall bar made on a
three-layer InAs/GaSb/InAs quantum well, we restore the Landau levels fan chart
by magnetotransport and unequivocally demonstrate a gapless state in our
sample. Measurements of cyclotron resonance at different electron
concentrations directly indicate a linear band crossing at the point
of Brillouin zone. Analysis of experimental data within analytical Dirac-like
Hamiltonian allows us not only determing velocity m/s of
massless Dirac fermions but also demonstrating significant non-linear
dispersion at high energies.Comment: Main text and Supplemental Materials, 14 pages, 9 figure
Uncovering the overlapping community structure of complex networks in nature and society
Many complex systems in nature and society can be described in terms of
networks capturing the intricate web of connections among the units they are
made of. A key question is how to interpret the global organization of such
networks as the coexistence of their structural subunits (communities)
associated with more highly interconnected parts. Identifying these a priori
unknown building blocks (such as functionally related proteins, industrial
sectors and groups of people) is crucial to the understanding of the structural
and functional properties of networks. The existing deterministic methods used
for large networks find separated communities, whereas most of the actual
networks are made of highly overlapping cohesive groups of nodes. Here we
introduce an approach to analysing the main statistical features of the
interwoven sets of overlapping communities that makes a step towards uncovering
the modular structure of complex systems. After defining a set of new
characteristic quantities for the statistics of communities, we apply an
efficient technique for exploring overlapping communities on a large scale. We
find that overlaps are significant, and the distributions we introduce reveal
universal features of networks. Our studies of collaboration, word-association
and protein interaction graphs show that the web of communities has non-trivial
correlations and specific scaling properties.Comment: The free academic research software, CFinder, used for the
publication is available at the website of the publication:
http://angel.elte.hu/clusterin
Anomalous self-diffusion in the ferromagnetic Ising chain with Kawasaki dynamics
We investigate the motion of a tagged spin in a ferromagnetic Ising chain
evolving under Kawasaki dynamics. At equilibrium, the displacement is Gaussian,
with a variance growing as . The temperature dependence of the
prefactor is derived exactly. At low temperature, where the static
correlation length is large, the mean square displacement grows as
in the coarsening regime, i.e., as a finite fraction of the
mean square domain length. The case of totally asymmetric dynamics, where
(resp. ) spins move only to the right (resp. to the left), is also
considered. In the steady state, the displacement variance grows as . The temperature dependence of the prefactor is derived exactly,
using the Kardar-Parisi-Zhang theory. At low temperature, the displacement
variance grows as in the coarsening regime, again proportionally to
the mean square domain length.Comment: 22 pages, 8 figures. A few minor changes and update
A convolute diversity of the Auriculariales (Agaricomycetes, Basidiomycota) with sphaeropedunculate basidia
Morphological and DNA data show that effused representatives of the Auriculariales (Basidiomycota) with sphaeropedunculate basidia belong to eleven genera of which seven are dealt with in this study. Among them, Myxarium is the largest genus containing 21 accepted species of which nine are reintroduced below and five are described as new. Protodontia is limited to three species only, P. subgelatinosa (the generic type) and two newly described species from Africa. Protoacia is a new monotypic genus for P. delicata, sp. nov., widely distributed on coniferous hosts in Eurasia. Myxariellum is erected for two new species with smooth hymenophore from northwestern North America while Gelacantha is introduced for G. pura, a new species with hydnoid hymenophore from Caucasus. Our data do not confirm the present synonymy of Sebacina sphaerospora with Tremella glaira, and these species are placed in two separate genera - Hydrophana, gen. nov., and Ofella, gen. nov., respectively. A key to European Myxarium and similar-looking species is included.Peer reviewe
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