Complex regional pain syndrome (CRPS), formerly known as Sudeck’s dystrophy and causalgia, is a disabling and distressing pain syndrome. We here provide a review based on the current literature ...concerning the epidemiology, etiology, pathophysiology, diagnosis, and therapy of CRPS. CRPS may develop following fractures, limb trauma or lesions of the peripheral or CNS. The clinical picture comprises a characteristic clinical triad of symptoms including autonomic (disturbances of skin temperature, color, presence of sweating abnormalities), sensory (pain and hyperalgesia), and motor (paresis, tremor, dystonia) disturbances. Diagnosis is mainly based on clinical signs. Several pathophysiological concepts have been proposed to explain the complex symptoms of CRPS: (i) facilitated neurogenic inflammation; (ii) pathological sympatho‐afferent coupling; and (iii) neuroplastic changes within the CNS. Furthermore, there is accumulating evidence that genetic factors may predispose for CRPS. Therapy is based on a multidisciplinary approach. Non‐pharmacological approaches include physiotherapy and occupational therapy. Pharmacotherapy is based on individual symptoms and includes steroids, free radical scavengers, treatment of neuropathic pain, and finally agents interfering with bone metabolism (calcitonin, biphosphonates). Invasive therapeutic concepts include implantation of spinal cord stimulators. This review covers new aspects of pathophysiology and therapy of CRPS.
We investigate the non-linear evolution of the matter power spectrum by using a large set of high-resolution N-body/hydrodynamic simulations. The linear matter power in the initial conditions is ...consistently modified to mimic the presence of warm dark matter (WDM) particles which induce a small-scale cut-off in the power as compared to standard cold dark matter scenarios. The impact of such thermal relics is examined at small scales k > 1 h Mpc−1, at redshifts of z < 5, which are particularly important for the next generation of Lyman α forest, weak lensing and galaxy clustering surveys. We measure the mass and redshift dependence of the WDM non-linear matter power and provide a fitting formula which is accurate at the ∼2 per cent level below z= 3 and for particle masses of m
WDM≥ 0.5 keV. The role of baryonic physics on the WDM-induced suppression is also quantified. In particular, we examine the effects of cooling, star formation and feedback from strong galactic winds. Finally, we find that a modified version of the halo model describes the shape of the WDM suppressed power spectra better than halofit. In the case of weak lensing however, the latter works better than the former, since it is more accurate on the relevant, mid-range scales, albeit very inaccurate on the smallest scales (k > 10 h Mpc−1) of the matter power spectrum.
Polymer modified bitumen Bulatović, V O; Rek, V; Marković, K J
Materials research innovations,
02/2012, Letnik:
16, Številka:
1
Journal Article
Recenzirano
Standard methods of characterisation of bitumen (BIT) and polymer modified bitumen (PMB) do not provide sufficient information. We propose to rely on determination of rheological properties which are ...much more informative. Along theses lines, we have determined rheology before and after the rolling thin film oven test. The materials studied were BIT, BIT+linear (L), styrene-butadiene-styrene (SBS), block copolymer, BIT+radial (R) and SBS copolymer. The rheological properties of the modified binders are characterised using a dynamic shear rheometer, over wide ranges of temperatures at a fixed traffic frequency of 10 rad s
−1
. The SBS block copolymers increase the elasticity of the BIT at high temperatures and contribute to a better flexibility at low temperatures. Polymer modified bitumens have higher resistance to permanent deformation. After aging, the hardening of BIT and PMBs occurred and the elastic response decreases as a consequence of degradation. The determined rheological properties are in agreement with the results of conventional tests.
In order to achievement new engineering properties, bitumen is mixed with polymers, thereby obtained blends that can have different physical or chemical structures, depending on the composition of ...the added polymer. The addition of polymers influences the rheological properties of polymer modified bitumens (PMBs), resistance to permanent deformation, PMBs stability under stress and temperature. Along theses lines, the PMBs blends with non-reactive polymers, elastomer styrene-butadiene-styrene with linear and radial structure, thermoplastic polymer ethylene-vinyl acetate and reactive polymer ethylene-butylacrylate-glycidylmethacrylate (Elvaloy), were prepared. Their rheological properties are characterised using dynamic shear rheometer, over wide ranges of temperatures at a fixed traffic frequency of 10 rad s
−1
both before and after thermooxidative aging. The aim was to established the influence of the polymer type on the bitumen engineering properties and evaluation of the polymer modifier effectiveness.
In recent years, forecasting activities have become an important tool in designing and optimising large-scale structure surveys. To predict the performance of such surveys, the Fisher matrix ...formalism is frequently used as a fast and easy way to compute constraints on cosmological parameters. Among them lies the study of the properties of dark energy which is one of the main goals in modern cosmology. As so, a metric for the power of a survey to constrain dark energy is provided by the figure of merit (FoM). This is defined as the inverse of the surface contour given by the joint variance of the dark energy equation of state parameters {
w
0
,
w
a
} in the Chevallier-Polarski-Linder parameterization, which can be evaluated from the covariance matrix of the parameters. This covariance matrix is obtained as the inverse of the Fisher matrix. The inversion of an ill-conditioned matrix can result in large errors on the covariance coefficients if the elements of the Fisher matrix are estimated with insufficient precision. The conditioning number is a metric providing a mathematical lower limit to the required precision for a reliable inversion, but it is often too stringent in practice for Fisher matrices with sizes greater than 2 × 2. In this paper, we propose a general numerical method to guarantee a certain precision on the inferred constraints, such as the FoM. It consists of randomly vibrating (perturbing) the Fisher matrix elements with Gaussian perturbations of a given amplitude and then evaluating the maximum amplitude that keeps the FoM within the chosen precision. The steps used in the numerical derivatives and integrals involved in the calculation of the Fisher matrix elements can then be chosen accordingly in order to keep the precision of the Fisher matrix elements below this maximum amplitude. We illustrate our approach by forecasting stage IV spectroscopic surveys cosmological constraints from the galaxy power spectrum. We infer the range of steps for which the Fisher matrix approach is numerically reliable. We explicitly check that using steps that are larger by a factor of two produce an inaccurate estimation of the constraints. We further validate our approach by comparing the Fisher matrix contours to those obtained with a Monte Carlo Markov chain (MCMC) approach – in the case where the MCMC posterior distribution is close to a Gaussian – and finding excellent agreement between the two approaches.
Background. Numerous studies have been conducted collecting normative values dependent on age for the three major components of the Sniffin' Stick Test (threshold of n-butanol, and identification and ...discrimination of odors). Less is known about the influence of age on the hedonic and intensity evaluation of odors. Thus, the objective of this study was to analyze the influence of age on the hedonic and intensity estimates in a large human population. Methods. Two hundred one single data sets established the Hedonic Database of Smell-Franconia (HeDoS-F) with the parameters age, gender, odor threshold, odor discrimination, oder identification, intensity estimates, and hedonic estimates (median age: 39 years, interquartile range: 28, minimum age: 19, maximum age: 83, men: 103, women: 98). For olfactory testing the Sniffin' Stick Test was used, and hedonic and intensity estimates were registered using visual analogue rating scales. For statistical analysis, we separated the study population into three age groups (19–39 years, 40–59 years, and ≥ 60 years), and parametric and nonparametric tests were calculated. Results. We found a significant influence of age on threshold, discrimination, and identification with a decrease in the higher age class. Over all odors the summed intensity estimates did not depend on age, whereas the summed relative hedonic estimates increased with the beginning of the fifth decade. Conclusion. Our study suggests that, for perceived odors, olfactory pleasure increases at later stages of the life span, whereas the perceived intensity of odors remains stable.
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