5,227 research outputs found
Total hip arthroplasty surgical approach does not alter postoperative gait mechanics one year after surgery
Objective: To investigate the differences in gait biomechanics on the basis of surgical approach 1 year after surgery. Design: This was a descriptive laboratory study to investigate the side-to-side differences in walking mechanics at a self-selected walking speed as well as a functional assessment 1year after total hip arthroplasty (THA). Temporospatial, kinetic, and kinematic data as well as functional outcomes were collected. Two-way analysis of variance was used to assess for between-group differences and limb-to-limb asymmetries. Setting: A controlled laboratory study. Participants: This study examined 35 patients with primary, unilateral THA. The THA surgical approaches that were used in these patients included 12 direct lateral, 18 posterior, and 11 anterolateral. All the patients were assessed 1 year after THA. Patients were excluded from the study if they had contralateral hip pain or pathology, or any prior lower extremity total joint replacements. Main Outcome Measurements: Three-dimensional lower extremity kinematics and kinetics as well as spatiotemporal variables were collected. In addition, a series of physical performance measures were collected. Results: No main effects for the physical performance measures or biomechanical variables were observed among the approach groups. Significant limb-to-limb asymmetries were observed among all the patients, with decreased sagittal plane range of motion, peak extension, and peak vertical ground reaction forces on the operative side. Conclusion: The results of this study indicated that no significant differences existed among the different surgical approach groups for any study variable. However, 1 year after THA, the patients demonstrated asymmetric gait patterns regardless of surgical approach, which indicated the potential need for continued intervention through physical therapy to regain normal side-to-side symmetry after THA. © 2014 American Academy of Physical Medicine and Rehabilitation
Patient centred diagnosis: sharing diagnostic decisions with patients in clinical practice.
Patient centred diagnosis is best practised through shared decision making; an iterative dialogue between doctor and patient, whichrespects a patient’s needs, values, preferences, and circumstances.
Shared decision making for diagnostic situations differs fundamentally from that for treatment decisions. This has important implications when considering its practical application.
The nature of dialogue should be tailored to the specific diagnostic decision; scenarios with higher stakes or uncertainty usually require more detailed conversation
Participating locally and nationally: explaining the offline and online activism of British party members
Drawing on survey data on the members of six British parties gathered in the immediate aftermath of the general election of 2015, this article addresses the question of what members do for their parties during campaigns. It identifies a key distinction between traditional forms of activity and more recent forms of online campaign participation. While the well-established general incentives theory of participation continues to offer a useful basis for explaining both types of campaign activism, we find that our understanding is significantly enhanced by considering the impact of national and local political contexts. Whereas the former chiefly adds explanatory value to the model of online participation by party members, the latter considerably improves the model of offline participation
Holographic Anomalous Conductivities and the Chiral Magnetic Effect
We calculate anomaly induced conductivities from a holographic gauge theory
model using Kubo formulas, making a clear conceptual distinction between
thermodynamic state variables such as chemical potentials and external
background fields. This allows us to pinpoint ambiguities in previous
holographic calculations of the chiral magnetic conductivity. We also calculate
the corresponding anomalous current three-point functions in special kinematic
regimes. We compare the holographic results to weak coupling calculations using
both dimensional regularization and cutoff regularization. In order to
reproduce the weak coupling results it is necessary to allow for singular
holographic gauge field configurations when a chiral chemical potential is
introduced for a chiral charge defined through a gauge invariant but
non-conserved chiral density. We argue that this is appropriate for actually
addressing charge separation due to the chiral magnetic effect.Comment: 17 pages, 1 figure. v2: 18 pages, 1 figure, discussion clarified
throughout the text, references added, version accepted for publication in
JHE
Anomalies and the chiral magnetic effect in the Sakai-Sugimoto model
In the chiral magnetic effect an imbalance in the number of left- and
right-handed quarks gives rise to an electromagnetic current parallel to the
magnetic field produced in noncentral heavy-ion collisions. The chiral
imbalance may be induced by topologically nontrivial gluon configurations via
the QCD axial anomaly, while the resulting electromagnetic current itself is a
consequence of the QED anomaly. In the Sakai-Sugimoto model, which in a certain
limit is dual to large-N_c QCD, we discuss the proper implementation of the QED
axial anomaly, the (ambiguous) definition of chiral currents, and the
calculation of the chiral magnetic effect. We show that this model correctly
contains the so-called consistent anomaly, but requires the introduction of a
(holographic) finite counterterm to yield the correct covariant anomaly.
Introducing net chirality through an axial chemical potential, we find a
nonvanishing vector current only before including this counterterm. This seems
to imply the absence of the chiral magnetic effect in this model. On the other
hand, for a conventional quark chemical potential and large magnetic field,
which is of interest in the physics of compact stars, we obtain a nontrivial
result for the axial current that is in agreement with previous calculations
and known exact results for QCD.Comment: 35 pages, 4 figures, v2: added comments about frequency-dependent
conductivity at the end of section 4; references added; version to appear in
JHE
Nodal dynamics, not degree distributions, determine the structural controllability of complex networks
Structural controllability has been proposed as an analytical framework for
making predictions regarding the control of complex networks across myriad
disciplines in the physical and life sciences (Liu et al.,
Nature:473(7346):167-173, 2011). Although the integration of control theory and
network analysis is important, we argue that the application of the structural
controllability framework to most if not all real-world networks leads to the
conclusion that a single control input, applied to the power dominating set
(PDS), is all that is needed for structural controllability. This result is
consistent with the well-known fact that controllability and its dual
observability are generic properties of systems. We argue that more important
than issues of structural controllability are the questions of whether a system
is almost uncontrollable, whether it is almost unobservable, and whether it
possesses almost pole-zero cancellations.Comment: 1 Figures, 6 page
Fracturing ranked surfaces
Discretized landscapes can be mapped onto ranked surfaces, where every
element (site or bond) has a unique rank associated with its corresponding
relative height. By sequentially allocating these elements according to their
ranks and systematically preventing the occupation of bridges, namely elements
that, if occupied, would provide global connectivity, we disclose that bridges
hide a new tricritical point at an occupation fraction , where
is the percolation threshold of random percolation. For any value of in the
interval , our results show that the set of bridges has a
fractal dimension in two dimensions. In the limit , a self-similar fracture is revealed as a singly connected line
that divides the system in two domains. We then unveil how several seemingly
unrelated physical models tumble into the same universality class and also
present results for higher dimensions
Why Are Male Social Relationships Complex in the Doubtful Sound Bottlenose Dolphin Population?
Copyright 2008 Elsevier B.V., All rights reserved.Peer reviewedPublisher PD
A cross-national study on the antecedents of work–life balance from the fit and balance perspective
Drawing on the perceived work–family fit and balance perspective, this study investigates demands and resources as antecedents of work–life balance (WLB) across four countries (New Zealand, France, Italy and Spain), so as to provide empirical cross-national evidence. Using structural equation modelling analysis on a sample of 870 full time employees, we found that work demands, hours worked and family demands were negatively related to WLB, while job autonomy and supervisor support were positively related to WLB. We also found evidence that resources (job autonomy and supervisor support) moderated the relationships between demands and work–life balance, with high resources consistently buffering any detrimental influence of demands on WLB. Furthermore, our study identified additional predictors of WLB that were unique to some national contexts. For example, in France and Italy, overtime hours worked were negatively associated with WLB, while parental status was positively associated with WLB. Overall, the implications for theory and practice are discussed.Peer ReviewedPostprint (author's final draft
The emerging structure of the Extended Evolutionary Synthesis: where does Evo-Devo fit in?
The Extended Evolutionary Synthesis (EES) debate is gaining ground in contemporary evolutionary biology. In parallel, a number of philosophical standpoints have emerged in an attempt to clarify what exactly is represented by the EES. For Massimo Pigliucci, we are in the wake of the newest instantiation of a persisting Kuhnian paradigm; in contrast, Telmo Pievani has contended that the transition to an EES could be best represented as a progressive reformation of a prior Lakatosian scientific research program, with the extension of its Neo-Darwinian core and the addition of a brand-new protective belt of assumptions and auxiliary hypotheses. Here, we argue that those philosophical vantage points are not the only ways to interpret what current proposals to ‘extend’ the Modern Synthesis-derived ‘standard evolutionary theory’ (SET) entail in terms of theoretical change in evolutionary biology. We specifically propose the image of the emergent EES as a vast network of models and interweaved representations that, instantiated in diverse practices, are connected and related in multiple ways. Under that assumption, the EES could be articulated around a paraconsistent network of evolutionary theories (including some elements of the SET), as well as models, practices and representation systems of contemporary evolutionary biology, with edges and nodes that change their position and centrality as a consequence of the co-construction and stabilization of facts and historical discussions revolving around the epistemic goals of this area of the life sciences. We then critically examine the purported structure of the EES—published by Laland and collaborators in 2015—in light of our own network-based proposal. Finally, we consider which epistemic units of Evo-Devo are present or still missing from the EES, in preparation for further analyses of the topic of explanatory integration in this conceptual framework
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