Paradoxical diffusion: Discriminating between normal and anomalous random walks

Commonly, normal diffusive behavior is characterized by a linear dependence of the second central moment on time, $\propto t$, while anomalous behavior is expected to show a different time dependence, $\propto t^{\delta}$ with $\delta 1$ for superdiffusive motions. Here we demonstrate that this kind of qualification, if applied straightforwardly, may be misleading: There are anomalous transport motions revealing perfectly "normal" diffusive character ($\propto t$), yet being non-Markov and non-Gaussian in nature. We use recently developed framework \cite[Phys. Rev. E \textbf{75}, 056702 (2007)]{magdziarz2007b} of Monte Carlo simulations which incorporates anomalous diffusion statistics in time and space and creates trajectories of such an extended random walk. For special choice of stability indices describing statistics of waiting times and jump lengths, the ensemble analysis of paradoxical diffusion is shown to hide temporal memory effects which can be properly detected only by examination of formal criteria of Markovianity (fulfillment of the Chapman-Kolmogorov equation).Comment: 8 pages, 7 figure

Bimodality and hysteresis in systems driven by confined L\'evy flights

We demonstrate occurrence of bimodality and dynamical hysteresis in a system describing an overdamped quartic oscillator perturbed by additive white and asymmetric L\'evy noise. Investigated estimators of the stationary probability density profiles display not only a turnover from unimodal to bimodal character but also a change in a relative stability of stationary states that depends on the asymmetry parameter of the underlying noise term. When varying the asymmetry parameter cyclically, the system exhibits a hysteresis in the occupation of a chosen stationary state.Comment: 4 pages, 5 figures, 30 reference

Content of the calcium and phosphorus in the meat of Prussian carp (Carassius auratus gibelio BLOCH, 1783) from the Lake Goplo (Poland)

The aim of this work was to compare the concentration of calcium and phosphorus and Ca/P ratio in the meat of Prussian carp (Carassius auratus gibelio) caught from the Lake Goplo. The study involved 14 individuals of fish caught in autumn (October, 26 2010). The muscles samples for analyses were taken from the whole body without the head and with the bones. Calcium concentration was determined by atomic absorption spectrophotometer Solar 969, Unicam. Phosphorus concentration was analysed using colorimetric method, by spectrophotometer Lambda 25, Perkin- Elmer. Measurements were performed at the analytical wavelength 430 nm. Analyses indicated that calcium concentration in the meat of Prussian carp was 5.63 g·kg-1. The mean content of P in the meat was 2.38 g·kg-1. Ratio of calcium to phosphorus in the meat of Prussian carp was 2.37:1. As analysis of correlation indicated there was a negative and statistical significant correlation between calcium and phosphorus concentration in the meat and the body length and the body mass of analysed fish collected from the Lake Goplo

Effect of ASA dose doubling versus switching to clopidogrel on plasma inflammatory markers concentration in patients with type 2 diabetes and high platelet reactivity: The AVOCADO study

Background: The aim of the study was to compare the effects of 2 strategies of antiplatelet treatment (i.e., 150 mg ASA vs. 75 mg clpoidogrel) on plasma level of inflammatory markers in type 2 diabetes mellitus (T2DM) patients with high platelet reactivity (HPR).Methods: Study cohort consisted of 304 T2DM patients on chronic ASA therapy (75 mg per day) participating in the Aspirin Versus/Or Clopidogrel in Aspirin-resistant Diabetics inflammation Outcomes (AVOCADO) study. Patients with HPR defined as Platelet Function Analyzer (PFA)-100 collagene/epinephrine closure time (CEPI-CT) < 193 s (n = 80) were randomized to 150 mg of ASA or 75 mg of clopidogrel in 2:3 ratio, respectively. Concentrations of the selected inflammatory markers, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, solubleCD40 ligand (sCD40L), and high sensitivity C-reactive protein (hsCRP), were measured and compared in both treatment groups before and after 8 weeks of treatment in both groups.Results: Out of 234 patients included into final analysis, the total of 34.2% (n = 80) patients displayed HPR, of which 14.1% (n = 33) were randomized into 150 mg of ASA group and 20.1% (n = 47) into 75 mg of clopidogrel group. Treatment with clopidogrel was a positive predictor (stepwise multiple regression analysis) of reduction of sCD40L concentration (odds ratio [OR] 4.15; p = 0.013), while treatment with 150 mg ASA was a positive predictor of reduction of IL-6 concentration (OR 4.38; p = 0.033). There was no statistically significant differences between clopidogrel and ASA 150 mg treatment in respect to predictive value for decreased hsCRP concentrations or increased TNF-α concentrations.Conclusions: Increasing the dose of ASA from 75 mg to 150 mg daily or switching ASA 75 mg to clopidogrel 75 mg daily may reduce concentrations of some inflammatory markers (in particular hsCRP, IL-6 and CD40L) in T2DM patients with HPR treated previously with 75 mg of ASA

Levy stable noise induced transitions: stochastic resonance, resonant activation and dynamic hysteresis

A standard approach to analysis of noise-induced effects in stochastic dynamics assumes a Gaussian character of the noise term describing interaction of the analyzed system with its complex surroundings. An additional assumption about the existence of timescale separation between the dynamics of the measured observable and the typical timescale of the noise allows external fluctuations to be modeled as temporally uncorrelated and therefore white. However, in many natural phenomena the assumptions concerning the abovementioned properties of "Gaussianity" and "whiteness" of the noise can be violated. In this context, in contrast to the spatiotemporal coupling characterizing general forms of non-Markovian or semi-Markovian L\'evy walks, so called L\'evy flights correspond to the class of Markov processes which still can be interpreted as white, but distributed according to a more general, infinitely divisible, stable and non-Gaussian law. L\'evy noise-driven non-equilibrium systems are known to manifest interesting physical properties and have been addressed in various scenarios of physical transport exhibiting a superdiffusive behavior. Here we present a brief overview of our recent investigations aimed to understand features of stochastic dynamics under the influence of L\'evy white noise perturbations. We find that the archetypal phenomena of noise-induced ordering are robust and can be detected also in systems driven by non-Gaussian, heavy-tailed fluctuations with infinite variance.Comment: 7 pages, 8 figure

Association of plasma concentrations of salicylic acid and high on ASA platelet reactivity in type 2 diabetes patients

Background: The objective of this study was to investigate the association between plasmaconcentrations of salicylic acid (SA) and other minor acetylsalicylic acid (ASA) metabolitesand high on ASA platelet reactivity assessed with different methods in type 2 diabetic patients(T2DM).Methods: Study cohort consisted of 293 T2DM patients on chronic ASA therapy. Plateletfunction inhibition was analyzed using measurements of serum thromboxane B2 (S-TxB2),VerifyNow Aspirin and Platelet Function Analyzer (PFA)-100 assays. The concentration of ASAmetabolites in plasma was measured with a high-performance liquid chromatography (HPLC).Results: In logistic regression analysis both ASA dose/kg of body weight and plasma SAconcentration were found to be predictive of S-TxB2 concentrations above 0.72 ng/mL cut-offpoint (OR 16.9, 95% CI 2.29–125.8, p = 0.006 and OR 5.34, 95% CI 2.67–10.68, p < 0.001,respectively). When using the VerifyNow Aspirin Assay, the concentrations of SA were signifi -cantly lower (p = 0.007) in the group with high on ASA platelet reactivity when compared withthe group with normal on ASA platelet reactivity. In logistic regression analysis plasma SAconcentration was found to be predictive of VerifyNow Aspirin Reaction Units (ARU) ≥ 550(OR 3.86, 95% CI 1.86–8.00, p < 0.001).Conclusions: Our study suggests that disturbances of pharmacokinetic mechanisms mightcontribute to lower plasma SA levels, and subsequently incomplete inhibition of thromboxane A2synthesis as measured with S-TxB2 concentrations and increased platelet reactivity measuredwith VerifyNow in T2DM patients

Trendy nr 4/2016

W nowym numerze TRENDÓW piszemy o kompetencjach kluczowych – informatycznych, matematycznych, technicznych, umiejętności uczenia się, innowacyjności i przedsiębiorczości. W kwietniu 2017 r. zastanowimy się nad tym, jak kształtować pozostałe – umiejętność porozumiewania się w języku ojczystymi obcym, kompetencje społeczne i obywatelskie, świadomość i ekspresję kulturalną. Kompetencje kluczowe to kompetencje, które wspierają rozwój osobisty, włączanie w życie społeczne, aktywne obywatelstwoi możliwość znalezienia zatrudnienia. Proces kształtowania i rozwijaniaw sobie kompetencji kluczowych trwa przez całe życie i nigdy się niekończy. Autorzy artykułów w tym numerze udowadniają, że kształtowanie kompetencji kluczowych nie jest trudne – to codzienność i stały element pracy w szkołach

The inner centromere is a biomolecular condensate scaffolded by the chromosomal passenger complex.

The inner centromere is a region on every mitotic chromosome that enables specific biochemical reactions that underlie properties, such as the maintenance of cohesion, the regulation of kinetochores and the assembly of specialized chromatin, that can resist microtubule pulling forces. The chromosomal passenger complex (CPC) is abundantly localized to the inner centromeres and it is unclear whether it is involved in non-kinase activities that contribute to the generation of these unique chromatin properties. We find that the borealin subunit of the CPC drives phase separation of the CPC in vitro at concentrations that are below those found on the inner centromere. We also provide strong evidence that the CPC exists in a phase-separated state at the inner centromere. CPC phase separation is required for its inner-centromere localization and function during mitosis. We suggest that the CPC combines phase separation, kinase and histone code-reading activities to enable the formation of a chromatin body with unique biochemical activities at the inner centromere