2,237 research outputs found
Re-injury Anxiety & Return-to-Sport Outcomes in College Students
When athletes are injured, they are faced with the initial injury stage, physical therapy, rehabilitation, and then the return-to-sport. When athletes have a negative outlook, they are less likely to recover from the injury at the proposed date of return-to-sport, take a longer span of time to recover, and have higher levels of stress and anxiety. Wadey, Podlog, Hall, Hamson-Utley, Hicks-Little, & Hammer, (2014) examined the dimensions of reinjury anxiety and found athletes with greater reinjury anxiety were in denial of the severity of their injury by wishing things would get better and had a greater focus on their distress. Significant indirect effects for coping were found for wishful thinking, venting of emotions, denial, and behavioral disengagement (Wadey et al., 2014). The purpose of the present study is to examine reinjury anxiety and return-to-sport outcomes within college students. Participants (n=100) solicited from Dominican University and different social networks will be sent an email containing the Reinjury Anxiety Inventory (Walker, Thatcher & Lavallee, 2010), the Return to Sport After Serious Injury Questionnaire (Podlog & Eklund, 2005) and demographic items including type of injury and sport. These questionnaires measure the level of reinjury anxiety and if the perspective of the injury is positive or negative. It is hypothesized: 1) Those with greater reinjury anxiety will be kept out of their sport longer than those who experience less reinjury anxiety and negative thoughts, 2) It will take the participants with greater anxiety longer to recover, and 3) With a negative attitude, personal perspective of actual length of injury will be skewed. Participants with a negative perspective will have higher anxiety with their injury versus participants with a more positive perspective. Data collection will begin approximately in February 2015
Instability of human societies as a result of conformity
We introduce a new model that mimics the strong and sudden effects induced by
conformity in tightly interacting human societies. Such effects range from mere
crowd phenomena to dramatic political turmoil. The model is a modified version
of the Ising Hamiltonian. We have studied the properties of this Hamiltonian
using both a Metropolis simulation and analytical derivations. Our study shows
that increasing the value of the conformity parameter, results in a first order
phase transition. As a result a majority of people begin honestly to support
the idea that may contradict the moral principles of a normal human beings
though each individual would support the moral principle without tight
interaction with the society. Thus, above some critical level of conformity our
society occurs to be instable with respect to ideas that might be doubtful. Our
model includes, in a simplified way, human diversity with respect to loyalty to
the moral principles.Comment: 5 pages, 5 figures, accepted in Int. journ of modern physics section
Measuring thermodynamic length
Thermodynamic length is a metric distance between equilibrium thermodynamic
states. Among other interesting properties, this metric asymptotically bounds
the dissipation induced by a finite time transformation of a thermodynamic
system. It is also connected to the Jensen-Shannon divergence, Fisher
information and Rao's entropy differential metric. Therefore, thermodynamic
length is of central interest in understanding matter out-of-equilibrium. In
this paper, we will consider how to define thermodynamic length for a small
system described by equilibrium statistical mechanics and how to measure
thermodynamic length within a computer simulation. Surprisingly, Bennett's
classic acceptance ratio method for measuring free energy differences also
measures thermodynamic length.Comment: 4 pages; Typos correcte
Generalized Jarzynski Equality under Nonequilibrium Feedback Control
The Jarzynski equality is generalized to situations in which nonequilibrium
systems are subject to a feedback control. The new terms that arise as a
consequence of the feedback describe the mutual information content obtained by
measurement and the efficacy of the feedback control. Our results lead to a
generalized fluctuation-dissipation theorem that reflects the readout
information, and can be experimentally tested using small thermodynamic
systems. We illustrate our general results by an introducing "information
ratchet," which can transport a Brownian particle in one direction and extract
a positive work from the particle
Quantum Brayton cycle with coupled systems as working substance
We explore the quantum version of Brayton cycle with a composite system as
the working substance. The actual Brayton cycle consists of two adiabatic and
two isobaric processes. Two pressures can be defined in our isobaric process,
one corresponds to the external magnetic field (characterized by ) exerted
on the system, while the other corresponds to the coupling constant between the
subsystems (characterized by ). As a consequence, we can define two types
of quantum Brayton cycle for the composite system. We find that the subsystem
experiences a quantum Brayton cycle in one quantum Brayton cycle (characterized
by ), whereas the subsystem's cycle is of quantum Otto in another Brayton
cycle (characterized by ). The efficiency for the composite system equals
to that for the subsystem in both cases, but the work done by the total system
are usually larger than the sum of work done by the two subsystems. The other
interesting finding is that for the cycle characterized by , the subsystem
can be a refrigerator while the total system is a heat engine. The result in
the paper can be generalized to a quantum Brayton cycle with a general coupled
system as the working substance.Comment: 7 pages, 3 figures, accepted by Phys. Rev.
THE INFLUENCE OF PSYCHOTHERAPY INTERVENTION IN MASS VIOLENCE SETTINGS: A CASE OF KENYA’S POST ELECTION VIOLENCE
Mass violence, just like Kenya’s Post election violence, inevitably always results in trauma, which, if not confronted with psychotropic medicine or therapy, may never heal. Consequently, the preparedness of humanitarian agencies to provide psychotherapy is an interventional strategy is important. This study sought to determine the extent to which, and factors that influence the use of psychotherapy in confronting trauma. It administered a questionnaire and an interview schedule to respondents drawn from IDPs and professionals from humanitarian agencies. The study found that psychotherapy covered about 84% of PEV victims and improved their social and personality adjustments. In addition, time response and intervener skills were found to be significant in improving its effectiveness. Key words: psychotherapy, trauma, violence, election, humanitarian agencies
Numerical renormalization group calculation of impurity internal energy and specific heat of quantum impurity models
We introduce a method to obtain the specific heat of quantum impurity models
via a direct calculation of the impurity internal energy requiring only the
evaluation of local quantities within a single numerical renormalization group
(NRG) calculation for the total system. For the Anderson impurity model, we
show that the impurity internal energy can be expressed as a sum of purely
local static correlation functions and a term that involves also the impurity
Green function. The temperature dependence of the latter can be neglected in
many cases, thereby allowing the impurity specific heat, , to be
calculated accurately from local static correlation functions; specifically via
, where and are the
energies of the (embedded) impurity and the hybridization energy, respectively.
The term involving the Green function can also be evaluated in cases where its
temperature dependence is non-negligible, adding an extra term to . For the non-degenerate Anderson impurity model, we show by comparison
with exact Bethe ansatz calculations that the results recover accurately both
the Kondo induced peak in the specific heat at low temperatures as well as the
high temperature peak due to the resonant level. The approach applies to
multiorbital and multichannel Anderson impurity models with arbitrary local
Coulomb interactions. An application to the Ohmic two state system and the
anisotropic Kondo model is also given, with comparisons to Bethe ansatz
calculations. The new approach could also be of interest within other impurity
solvers, e.g., within quantum Monte Carlo techniques.Comment: 16 pages, 15 figures, published versio
AFM pulling and the folding of donor-acceptor oligorotaxanes: phenomenology and interpretation
The thermodynamic driving force in the self-assembly of the secondary
structure of a class of donor-acceptor oligorotaxanes is elucidated by means of
molecular dynamics simulations of equilibrium isometric single-molecule force
spectroscopy AFM experiments. The oligorotaxanes consist of
cyclobis(paraquat-\emph{p}-phenylene) rings threaded onto an oligomer of
1,5-dioxynaphthalenes linked by polyethers. The simulations are performed in a
high dielectric medium using MM3 as the force field. The resulting force vs.
extension isotherms show a mechanically unstable region in which the molecule
unfolds and, for selected extensions, blinks in the force measurements between
a high-force and a low-force regime. From the force vs. extension data the
molecular potential of mean force is reconstructed using the weighted histogram
analysis method and decomposed into energetic and entropic contributions. The
simulations indicate that the folding of the oligorotaxanes is energetically
favored but entropically penalized, with the energetic contributions overcoming
the entropy penalty and effectively driving the self-assembly. In addition, an
analogy between the single-molecule folding/unfolding events driven by the AFM
tip and the thermodynamic theory of first-order phase transitions is discussed
and general conditions, on the molecule and the cantilever, for the emergence
of mechanical instabilities and blinks in the force measurements in equilibrium
isometric pulling experiments are presented. In particular, it is shown that
the mechanical stability properties observed during the extension are
intimately related to the fluctuations in the force measurements.Comment: 42 pages, 17 figures, accepted to the Journal of Chemical Physic
Proof of Rounding by Quenched Disorder of First Order Transitions in Low-Dimensional Quantum Systems
We prove that for quantum lattice systems in d<=2 dimensions the addition of
quenched disorder rounds any first order phase transition in the corresponding
conjugate order parameter, both at positive temperatures and at T=0. For
systems with continuous symmetry the statement extends up to d<=4 dimensions.
This establishes for quantum systems the existence of the Imry-Ma phenomenon
which for classical systems was proven by Aizenman and Wehr. The extension of
the proof to quantum systems is achieved by carrying out the analysis at the
level of thermodynamic quantities rather than equilibrium states.Comment: This article presents the detailed derivation of results which were
announced in Phys. Rev. Lett. 103 (2009) 197201 (arXiv:0907.2419). v3
incorporates many corrections and improvements resulting from referee
comment
An Exact Solution to O(26) Sigma Model coupled to 2-D Gravity
By a mapping to the bosonic string theory, we present an exact solution to
the O(26) sigma model coupled to 2-D quantum gravity. In particular, we obtain
the exact gravitational dressing to the various matter operators classified by
the irreducible representations of O(26). We also derive the exact form of the
gravitationally modified beta function for the original coupling constant
. The relation between our exact solution and the asymptotic solution
given in ref[3] is discussed in various aspects.Comment: 10 pages, pupt-144
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