Fractional Cauchy problems on bounded domains: survey of recent results

In a fractional Cauchy problem, the usual first order time derivative is replaced by a fractional derivative. This problem was first considered by \citet{nigmatullin}, and \citet{zaslavsky} in $\mathbb R^d$ for modeling some physical phenomena. The fractional derivative models time delays in a diffusion process. We will give a survey of the recent results on the fractional Cauchy problem and its generalizations on bounded domains D\subset \rd obtained in \citet{m-n-v-aop, mnv-2}. We also study the solutions of fractional Cauchy problem where the first time derivative is replaced with an infinite sum of fractional derivatives. We point out a connection to eigenvalue problems for the fractional time operators considered. The solutions to the eigenvalue problems are expressed by Mittag-Leffler functions and its generalized versions. The stochastic solution of the eigenvalue problems for the fractional derivatives are given by inverse subordinators

Heart Rate Variability and Non-Linear Dynamics in Risk Stratification

The time-domain measures and power–spectral analysis of heart rate variability (HRV) are classic conventional methods to assess the complex regulatory system between autonomic nervous system and heart rate and are most widely used. There are abundant scientific data about the prognostic significance of the conventional measurements of HRV in patients with various conditions, particularly with myocardial infarction. Some studies have suggested that some newer measures describing non-linear dynamics of heart rate, such as fractal measures, may reveal prognostic information beyond that obtained by the conventional measures of HRV. An ideal risk indicator could specifically predict sudden arrhythmic death as the implantable cardioverter-defibrillator (ICD) therapy can prevent such events. There are numerically more sudden deaths among post-infarction patients with better preserved left ventricular function than in those with severe left ventricular dysfunction. Recent data support the concept that HRV measurements, when analyzed several weeks after acute myocardial infarction, predict life-threatening ventricular tachyarrhythmias in patients with moderately depressed left ventricular function. However, well-designed prospective randomized studies are needed to evaluate whether the ICD therapy based on the assessment of HRV alone or with other risk indicators improves the patients’ prognosis. Several issues, such as the optimal target population, optimal timing of HRV measurements, optimal methods of HRV analysis, and optimal cutpoints for different HRV parameters, need clarification before the HRV analysis can be a widespread clinical tool in risk stratification

Evaluation of maxillary canine and molar movement during the first phase of extraction space closure: a multilevel analysis

ABSTRACT Objective: This study was designed to analyze and compare the cusp and apex movements of the maxillary canines and first molars during canine retraction in the first step of extraction space closure, and to evaluate if these teeth follow a curvilinear (acceleration and/or deceleration) movement rate. Material and Methods: Twenty-five patients (23.3 ± 5.1 years of age) were enrolled. The retraction of the maxillary canines was accomplished using nickel-titanium closed coil springs (100gf) on 0.020-in stainless steel archwire. Oblique cephalograms were traced and superimposed on the anatomic best fit of the maxilla (before the retraction [T0], and after one month [T1], three [T3], five [T5] and seven [T7] months). Statistics was based in a normally distributed data. Multilevel procedures were used to derive polynomials for each of the measurements. Student’s t-test and one-way repeated measures ANOVA were conducted. The level of significance of 5% was adopted. Results: Canine cusps and apexes did not follow a quadratic curve regarding horizontal movement (neither accelerate nor decelerate). Canine and molar cusps showed more horizontal movement than apexes (4.80 mm vs. 2.78 mm, and 2.64 mm vs. 2.17 mm, respectively). Conclusions: Canine did not accelerate or decelerate overtime horizontally; the cusps and apexes of the canines and molars showed more horizontal movement and larger rate at the beginning of canine retraction, followed by significantly smaller and constant movement rate after the first month

Antitumor Activity of TRAIL Recombinant Adenovirus in Human Malignant Glioma Cells

Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL) has been reported to specifically kill malignant cells but to be relatively nontoxic to normal cells. One of disadvantages to previous in vivo protocols was the need for large quantities of TRAIL recombinant protein to suppress tumor growth. To evaluate the antitumor activity and therapeutic value of the TRAIL gene, we constructed adenoviral vectors expressing the human TRAIL gene (Ad.hTRAIL) and transferred them into malignant glioma cells in vitro and tumors in vivo, as an alternative to recombinant soluble TRAIL protein. The results show that TRAIL-sensitive glioma cells infected Ad.hTRAIL undergo apoptosis through the production and expression of TRAIL protein. The in vitro transfer elicited apoptosis, as demonstrated by the quantification of viable or apoptotic cells and by the analysis of cleavage of poly (ADP-ribose) polymerase. Furthermore, in vivo administration of Ad.hTRAIL at the site of tumor implantation suppressed the outgrowth of human glioma xenografts in SCID mice. These results further define Ad.hTRAIL as an anti-tumor therapeutic and demonstrate its potential use as an alternative approach to treatment for malignant glioma

Intramuscular Stimulation of Muscle Afferents Attains Prolonged Tremor Reduction in Essential Tremor Patients

This study proposes and clinically tests intramuscular electrical stimulation below motor threshold to achieve prolonged reduction of wrist flexion/extension tremor in Essential Tremor (ET) patients. The developed system consisted of an intramuscular thin-film electrode structure that included both stimulation and electromyography (EMG) recording electrodes, and a control algorithm for the timing of intramuscular stimulation based on EMG (closed-loop stimulation). Data were recorded from nine ET patients with wrist flexion/extension tremor recruited from the Gregorio Mara\uf1\uf3n Hospital (Madrid, Spain). Patients participated in two experimental sessions comprising: 1) sensory stimulation of wrist flexors/extensors via thin-film multichannel intramuscular electrodes; and 2) surface stimulation of the nerves innervating the same target muscles. For each session, four of these patients underwent random 60-s trials of two stimulation strategies for each target muscle: 1) selective and adaptive timely stimulation (SATS) - based on EMG of the antagonist muscle; and 2) continuous stimulation (CON) of target muscles. Two patients underwent SATS stimulation trials alone while the other three underwent CON stimulation trials alone in each session. Kinematics of wrist, elbow, and shoulder, together with clinical scales, were used to assess tremor before, right after, and 24 h after each session. Intramuscular SATS achieved, on average, 32% acute (during stimulation) tremor reduction on each trial, while continuous stimulation augmented tremorgenic activity. Furthermore, tremor reduction was significantly higher using intramuscular than surface stimulation. Prolonged reduction of tremor amplitude (24 h after the experiment) was observed in four patients. These results showed acute and prolonged (24 h) tremor reduction using a minimally invasive neurostimulation technology based on SATS of primary sensory afferents of wrist muscles. This strategy might open the possibility of an alternative therapeutic approach for ET patients

Dynamics of conflicts in Wikipedia

In this work we study the dynamical features of editorial wars in Wikipedia (WP). Based on our previously established algorithm, we build up samples of controversial and peaceful articles and analyze the temporal characteristics of the activity in these samples. On short time scales, we show that there is a clear correspondence between conflict and burstiness of activity patterns, and that memory effects play an important role in controversies. On long time scales, we identify three distinct developmental patterns for the overall behavior of the articles. We are able to distinguish cases eventually leading to consensus from those cases where a compromise is far from achievable. Finally, we analyze discussion networks and conclude that edit wars are mainly fought by few editors only.Comment: Supporting information adde

Two-orbital SU(N) magnetism with ultracold alkaline-earth atoms

Fermionic alkaline-earth atoms have unique properties that make them attractive candidates for the realization of novel atomic clocks and degenerate quantum gases. At the same time, they are attracting considerable theoretical attention in the context of quantum information processing. Here we demonstrate that when such atoms are loaded in optical lattices, they can be used as quantum simulators of unique many-body phenomena. In particular, we show that the decoupling of the nuclear spin from the electronic angular momentum can be used to implement many-body systems with an unprecedented degree of symmetry, characterized by the SU(N) group with N as large as 10. Moreover, the interplay of the nuclear spin with the electronic degree of freedom provided by a stable optically excited state allows for the study of spin-orbital physics. Such systems may provide valuable insights into strongly correlated physics of transition metal oxides, heavy fermion materials, and spin liquid phases.Comment: 15 pages, 10 figures. V2: extended experimental accessibility and Kondo sections in the main text (including new Fig. 5b) and in the Methods; reorganized other parts; added reference

GSTM1, GSTT1 and GSTP1 Polymorphisms in the Korean Population

The isoenzymes of the glutathione s transferase (GST) family play a vital role in phase II of biotransformation of many substances. Using a multiplex polymerase chain reaction and a direct sequencing analysis, the frequencies of GSTM1, GSTT1, and GSTP1 polymorphisms were evaluated in 1,051 Korean male subjects. We found that 53.8% of the individuals had the GSTM1 null genotype and 54.3% had the GSTT 1 null genotype. The genotypic distribution of GSTP1 was Ile105/Ile105 in 68.4%, Ile105/Val105 in 29.1% and Val105/Val105 in 2.5%. The most frequently observed combination of GSTM1, GSTP1 and GSTT1 genotypes was Null type/Ile105/Ile105/Null type, while the combination of Non-null type/Val105/Val105/Non-Null type was not observed. We found that the genotype distributions of three GST isoenzymes in the Koreans are similar to those reported in Asians and previously reported Koreans. We believe our results, which are represented by a large population, are reliable estimates of the frequencies of the polymorphic GST alleles in the Koreans and will help future researches on GST polymorphisms