Subjective Cognitive Dysfunction in Patients With and Without Fibromyalgia:Prevalence, Predictors, Correlates, and Consequences

Background: Subjective cognitive dysfunction (SCD) is common in fibromyalgia (FM), where it has been called 'fibrofog.' But its predictors and correlates are not well understood, including the extent to which SCD is present in fibromyalgia and non-fibromyalgia clinical populations. In addition, there are no studies available concerning SCD and fibromyalgia in the general population. We investigated these issues in a longitudinal rheumatic disease research databank and two cross-sectional general population studies. Methods: 11,150 unselected patients with rheumatoid arthritis completed an assessment of FM and cognitive severity (CS) status using the full 0-3 fibromyalgia 2016 criteria assessment. In addition, CS was dummy coded as present/absent (CS+). Assessments of SCD and fibromyalgia prevalence were available in two German general population studies. Results: Fibromyalgia was present (FM+) in 2,493 (21.7%) of clinical subjects and absent (FM-) in 9,017 (78.3%) by FM 2016 criteria. Cognitive severity was present in 1,304 (52.3%) of those with fibromyalgia and 1,009 (11.2%) of non-fibromyalgia subjects (FM-). In two general population studies, 42.0% to 52.3% of those with fibromyalgia were CS+ as were 1.4% to 5.5% of FM- subjects. Patients with CS+ had more abnormal scores for every measure of rheumatoid arthritis (RA) severity, fibromyalgia severity, and general health. The presence of CS+ was strongly related to somatic and non-somatic symptoms scores and less strongly to pain variables. The best predictor of CS+ in the clinic and the general population was the symptom severity scale (SSS), a criterion of fibromyalgia. Conclusions: Persons with SCD have high counts of somatic and psychological symptoms. Subjective cognitive dysfunction is best predicted by a simple symptoms score, and not by pain extent scores. Although SCD is called fibrofog in patients with FM, 43.6% of CS+ cases occurred in FM- subjects. Fibromyalgia and CS are correlated but appear to be different parts of a symptom severity continuum. 'Fibrofog' as a phenomenon linked only to fibromyalgia is a misnomer because it can be identified in many non-fibromyalgia patients as well

Monte Carlo Simulation Calculation of Critical Coupling Constant for Continuum \phi^4_2

We perform a Monte Carlo simulation calculation of the critical coupling constant for the continuum {\lambda \over 4} \phi^4_2 theory. The critical coupling constant we obtain is [{\lambda \over \mu^2}]_crit=10.24(3).Comment: 11 pages, 4 figures, LaTe

Cluster Expansion Approach to the Effective Potential in Φ2+14\Phi^4_{2+1}-Theory

We apply a truncated set of dynamical equations of motion for connected equal-time Green functions up to the 4-point level to the investigation of spontaneous ground state symmetry breaking in $\Phi^4_{2+1}$ quantum field theory. Within our momentum space discretization we obtain a second order phase transition as soon as the connected 3-point function is included. However, an additional inclusion of the connected 4-point function still shows a significant influence on the shape of the effective potential and the critical coupling.Comment: 1 compressed uuencoded postscript file with 5 figures included, 21 page

Connected Green function approach to ground state symmetry breaking in Φ1+14\Phi^4_{1+1}-theory

Using the cluster expansions for n-point Green functions we derive a closed set of dynamical equations of motion for connected equal-time Green functions by neglecting all connected functions higher than $4^{th}$ order for the $\lambda \Phi^4$-theory in $1+1$ dimensions. We apply the equations to the investigation of spontaneous ground state symmetry breaking, i.e. to the evaluation of the effective potential at temperature $T=0$. Within our momentum space discretization we obtain a second order phase transition (in agreement with the Simon-Griffith theorem) and a critical coupling of $\lambda_{crit}/4m^2=2.446$ as compared to a first order phase transition and $\lambda_{crit}/4m^2=2.568$ from the Gaussian effective potential approach.Comment: 25 Revtex pages, 5 figures available via fpt from the directory ugi-94-11 of [email protected] as one postscript file (there was a bug in our calculations, all numerical results and figures have changed significantly), ugi-94-1

Ultrafast optically induced spin transfer in ferromagnetic alloys

The vision of using light to manipulate electronic and spin excitations in materials on their fundamental time and length scales requires new approaches in experiment and theory to observe and understand these excitations. The ultimate speed limit for all-optical manipulation requires control schemes for which the electronic or magnetic subsystems of the materials are coherently manipulated on the time scale of the laser excitation pulse. In our work, we provide experimental evidence of such a direct, ultrafast, and coherent spin transfer between two magnetic subsystems of an alloy of Fe and Ni. Our experimental findings are fully supported by time-dependent density functional theory simulations and, hence, suggest the possibility of coherently controlling spin dynamics on subfemtosecond time scales, i.e., the birth of the research area of attomagnetism

Biodiversity into your hands - A call for a virtual global natural history 'metacollection'

10.1186/1742-9994-10-55Frontiers in Zoology101

Quantum dynamics and thermalization for out-of-equilibrium phi^4-theory

The quantum time evolution of \phi^4-field theory for a spatially homogeneous system in 2+1 space-time dimensions is investigated numerically for out-of-equilibrium initial conditions on the basis of the Kadanoff-Baym equations including the tadpole and sunset self-energies. Whereas the tadpole self-energy yields a dynamical mass, the sunset self-energy is responsible for dissipation and an equilibration of the system. In particular we address the dynamics of the spectral (`off-shell') distributions of the excited quantum modes and the different phases in the approach to equilibrium described by Kubo-Martin-Schwinger relations for thermal equilibrium states. The investigation explicitly demonstrates that the only translation invariant solutions representing the stationary fixed points of the coupled equation of motions are those of full thermal equilibrium. They agree with those extracted from the time integration of the Kadanoff-Baym equations in the long time limit. Furthermore, a detailed comparison of the full quantum dynamics to more approximate and simple schemes like that of a standard kinetic (on-shell) Boltzmann equation is performed. Our analysis shows that the consistent inclusion of the dynamical spectral function has a significant impact on relaxation phenomena. The different time scales, that are involved in the dynamical quantum evolution towards a complete thermalized state, are discussed in detail. We find that far off-shell 1 3 processes are responsible for chemical equilibration, which is missed in the Boltzmann limit. Finally, we address briefly the case of (bare) massless fields. For sufficiently large couplings $\lambda$ we observe the onset of Bose condensation, where our scheme within symmetric \phi^4-theory breaks down.Comment: 77 pages, 26 figure

Systematic review with meta-analysis: cytokines in fibromyalgia syndrome

<p>Abstract</p> <p>Background</p> <p>To perform a systematic review and meta-analysis on cytokine levels in patients with fibromyalgia syndrome (FMS).</p> <p>Methods</p> <p>Through December 2010 we systematically reviewed the databases PubMed, MEDLINE, and PsycINFO and screened the reference lists of 22 review articles for suitable original articles. Original articles investigating cytokines in patients with FMS were included. Data were extracted by two independent authors. Differences of the cytokine levels of FMS patients and controls were summarized by standardized mean differences (SMD) using a random effects model. Study quality was assessed applying methodological scores: modified Center of Evidence Based Medicine, Newcastle-Ottawa-Scale, and Würzburg Methodological Quality Score.</p> <p>Results</p> <p>Twenty-five articles were included investigating 1255 FMS patients and 800 healthy controls. Data of 13/25 studies entered meta-analysis. The overall methodological quality of studies was low. The results of the majority of studies were not comparable because methods, investigated material, and investigated target cytokines differed. Systematic review of the selected 25 articles revealed that FMS patients had higher serum levels of interleukin (IL)-1 receptor antagonist, IL-6, and IL-8, and higher plasma levels of IL-8. Meta-analysis of eligible studies showed that FMS patients had higher plasma IL-6 levels compared to controls (SMD = -0.34 [-0.64, -0.03] 95% CI; p = 0.03). The majority of investigated cytokines were not different between patients and controls.</p> <p>Conclusions</p> <p>The pathophysiological role of cytokines in FMS is still unclear. Studies of higher quality and with higher numbers of subjects are needed.</p