135 research outputs found
Localization-delocalization transition on a separatrix system of nonlinear Schrodinger equation with disorder
Localization-delocalization transition in a discrete Anderson nonlinear
Schr\"odinger equation with disorder is shown to be a critical phenomenon
similar to a percolation transition on a disordered lattice, with the
nonlinearity parameter thought as the control parameter. In vicinity of the
critical point the spreading of the wave field is subdiffusive in the limit
. The second moment grows with time as a powerlaw , with exactly 1/3. This critical spreading finds its
significance in some connection with the general problem of transport along
separatrices of dynamical systems with many degrees of freedom and is
mathematically related with a description in terms fractional derivative
equations. Above the delocalization point, with the criticality effects
stepping aside, we find that the transport is subdiffusive with
consistently with the results from previous investigations. A threshold for
unlimited spreading is calculated exactly by mapping the transport problem on a
Cayley tree.Comment: 6 pages, 1 figur
E-pile model of self-organized criticality
The concept of percolation is combined with a self-consistent treatment of
the interaction between the dynamics on a lattice and the external drive. Such
a treatment can provide a mechanism by which the system evolves to criticality
without fine tuning, thus offering a route to self-organized criticality (SOC)
which in many cases is more natural than the weak random drive combined with
boundary loss/dissipation as used in standard sand-pile formulations. We
introduce a new metaphor, the e-pile model, and a formalism for electric
conduction in random media to compute critical exponents for such a system.
Variations of the model apply to a number of other physical problems, such as
electric plasma discharges, dielectric relaxation, and the dynamics of the
Earth's magnetotail.Comment: 4 pages, 2 figure
Fracton pairing mechanism for "strange" superconductors: Self-assembling organic polymers and copper-oxide compounds
Self-assembling organic polymers and copper-oxide compounds are two classes
of "strange" superconductors, whose challenging behavior does not comply with
the traditional picture of Bardeen, Cooper, and Schrieffer (BCS)
superconductivity in regular crystals. In this paper, we propose a theoretical
model that accounts for the strange superconducting properties of either class
of the materials. These properties are considered as interconnected
manifestations of the same phenomenon: We argue that superconductivity occurs
in the both cases because the charge carriers (i.e., electrons or holes)
exchange {\it fracton excitations}, quantum oscillations of fractal lattices
that mimic the complex microscopic organization of the strange superconductors.
For the copper oxides, the superconducting transition temperature as
predicted by the fracton mechanism is of the order of K. We suggest
that the marginal ingredient of the high-temperature superconducting phase is
provided by fracton coupled holes that condensate in the conducting
copper-oxygen planes owing to the intrinsic field-effect-transistor
configuration of the cuprate compounds. For the gate-induced superconducting
phase in the electron-doped polymers, we simultaneously find a rather modest
transition temperature of K owing to the limitations imposed by
the electron tunneling processes on a fractal geometry. We speculate that
hole-type superconductivity observes larger onset temperatures when compared to
its electron-type counterpart. This promises an intriguing possibility of the
high-temperature superconducting states in hole-doped complex materials. A
specific prediction of the present study is universality of ac conduction for
.Comment: 12 pages (including separate abstract page), no figure
RESVERATROL IN KUBAN WINES
Purpose: The main purpose of viticulture is to improve the quality of the grapes, both to a greater extent for ampelotherapy and winemaking, and, to a lesser extent, to onotherapy.
Methodology: The article highlights the results of perennial (from 2014) studies of 18 promising technical grape varieties from different zones of the Krasnodar Territory: Anapo-Taman, Central, as well as Amur from the Black Sea zone of the Krasnodar Territory and two control Western European world-famous and most common varieties Merlot and Cabernet-Sauvignon in the same zones.
Result: The average values of resveratrol were found in wine materials from the varieties Vladimir and Dmitry (4.7 mg / dm3), Podlesny (3.9 mg / dm3), Saperavi Severny (3.5 mg / dm3), 40 let Octiabria (3.3 mg / dm3), Kurchansky and 40 let Pobedy (3.0 and 2.9 mg / dm3, respectively). On the other hand, as shown by the analysis of wine materials, the Antaris, Varyushkin, Mitsar and Plechistik varieties synthesize a lower content of resveratrol (1.0 and 0.9 mg / dm3, respectively).
Applications: This research can be used for the universities, teachers and education students.
Novelty/Originality: In this research, the model of resveratrol in Kuban wines is presented in a comprehensive and complete manner
Nutritional Status Disorders in Chronic Kidney Disease: Practical Aspects (Systematic Review)
Despite the significant achievements in the management of chronic kidney disease (CKD) patients, the mortality rate of these patients still remains high. Nutritional status disorders (NSD) are considered now as one of the prognostic risk factors not only for dialysis but also for predialysis CKD stages. Since the publication of KDIGO 2012 guidelines for CKD patientâs management, there has been some significant advancement in our understanding of main NSD mechanisms in CKD, including different nosological group patients (first, in diabetic and systemic diseases patients). At the same time, there is still an urgent need for randomized trials for better-informed decisions and future optimization of CKD patientsâ care. This chapter provides the current data on all aspects of NSD in CKD: etiology, diagnosis, prevention, and treatment approaches, as well as on risk factors of NSD at predialysis stages and in chronic hemodialysis patients. Considerable attention was devoted to the diagnosis and differential diagnosis of NSD in CKD patients. It was determined that the overall strategy for dietary treatment contributed to improving the life quality of patients and slowing down of CKD progression. The review is written based on the published results of clinical studies performed on the position of evidence-based medicine
Disorders in the System of Mineral and Bone Metabolism RegulatorsâFGF-23, Klotho and Sclerostinâin Chronic Kidney Disease: Clinical Significance and Possibilities for Correction
The chapter discusses the current understanding of the system of mineral and bone metabolism regulatorsâFGF-23, Klotho and sclerostinâdisturbances in chronic kidney disease (CKD). In the chapter we presented the date, including our own results, which allow to suggest the change in the ratio of FGF-23-Klotho-sclerostin in CKD as an early biomarker not only for the chronic kidney damage but also for high cardiovascular (CV) risk. Results of studies show that disorders in FGF-23-Klotho-sclerostin ratio correlate with the frequency and severity of hypertension, vascular calcification, cardiac remodelling, anaemia, malnutrition, inflammation and strong aggravate CV risk in CKD. It was found independent from blood pressure (BP) action of increased serum FGF-23 on the myocardium as well as the correlation of serum high-sensitive troponin I with increased serum FGF-23 and low Klotho levels in CKD patients. At the same time, it was shown that renoprotective therapy, including renin-angiotensin blockers, low-protein diet with amino/keto acid supplementation and phosphate binders, erythropoiesis stimulators, vitamin D metabolites used to get the target levels of BP, serum phosphorus, haemoglobin, parathyroid hormone and nutritional status disorders correction can reduce the risk of CV events, as the major cause of death in CKD patients
Quality of life of chronic kidney disease patients on renal replacement therapy
The study demonstrated the results of the comparative analysis of various types of renal replacement therapy effects on the quality of life patients with terminal stage of chronic kidney disease on the basis of standardized questionnaires. It has been shown that the quality of life is significantly improved after a kidney transplantation. At the same time, it has also been found that the introduction of home dialysis, epoetins, active metabolites of vitamin D, calcimimetics in the clinic care expanded the opportunities for the labor rehabilitation of the dialysis patients and made their quality of life comparable with the same of the kidney transplant recipients
A nonextensive entropy approach to solar wind intermittency
The probability distributions (PDFs) of the differences of any physical
variable in the intermittent, turbulent interplanetary medium are scale
dependent. Strong non-Gaussianity of solar wind fluctuations applies for short
time-lag spacecraft observations, corresponding to small-scale spatial
separations, whereas for large scales the differences turn into a Gaussian
normal distribution. These characteristics were hitherto described in the
context of the log-normal, the Castaing distribution or the shell model. On the
other hand, a possible explanation for nonlocality in turbulence is offered
within the context of nonextensive entropy generalization by a recently
introduced bi-kappa distribution, generating through a convolution of a
negative-kappa core and positive-kappa halo pronounced non-Gaussian structures.
The PDFs of solar wind scalar field differences are computed from WIND and ACE
data for different time lags and compared with the characteristics of the
theoretical bi-kappa functional, well representing the overall scale dependence
of the spatial solar wind intermittency. The observed PDF characteristics for
increased spatial scales are manifest in the theoretical distribution
functional by enhancing the only tuning parameter , measuring the
degree of nonextensivity where the large-scale Gaussian is approached for
. The nonextensive approach assures for experimental studies
of solar wind intermittency independence from influence of a priori model
assumptions. It is argued that the intermittency of the turbulent fluctuations
should be related physically to the nonextensive character of the
interplanetary medium counting for nonlocal interactions via the entropy
generalization.Comment: 17 pages, 7 figures, accepted for publication in Astrophys.
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