Adaptive Mixture Methods Based on Bregman Divergences

We investigate adaptive mixture methods that linearly combine outputs of $m$ constituent filters running in parallel to model a desired signal. We use "Bregman divergences" and obtain certain multiplicative updates to train the linear combination weights under an affine constraint or without any constraints. We use unnormalized relative entropy and relative entropy to define two different Bregman divergences that produce an unnormalized exponentiated gradient update and a normalized exponentiated gradient update on the mixture weights, respectively. We then carry out the mean and the mean-square transient analysis of these adaptive algorithms when they are used to combine outputs of $m$ constituent filters. We illustrate the accuracy of our results and demonstrate the effectiveness of these updates for sparse mixture systems.Comment: Submitted to Digital Signal Processing, Elsevier; IEEE.or

A novel approach for preventing esophageal stricture formation: olmesartan prevented apoptosis

Accidentally ingested corrosive substances can cause functional and structural damage to the esophageal tissue resulting in stricture formation. It has been reported that the administration of olmesartan (OLM) can have anti-inflammatory, antifibrotic and antiapoptotic effects on injured tissue. The aim of our study was to check if OLM could prevent formation of scars in the corrosive esophageal burn model. Fifty-one Wistar Albino rats were divided into six groups: Control, Sham, OLM, Sham + OLM, Burn, and Burn + OLM. Olmesartan (5 mg/kg) was given by gavage once per day for 21 consecutive days after injury. The morphology of the esophagus was assessed after Masson trichrome staining, and apoptosis was evaluated using the terminal deoxynucleotidyl transferased UTP nick end labeling (TUNEL) method. The serum nucleosomes (as an indicator of apoptosis), serum p53 protein, and esophageal tissue p53 protein levels of each group were measured by immunoassays. Muscularis mucosa damage, submucosal collagen deposition, and tunica muscularis injury in the Burn + OLM group decreased significantly compared with the Burn group (p < 0.05). Similarly, the number of apoptotic cells in the Burn + OLM group decreased compared with the Burn group (p < 0.05). Serum levels of nucleosomes and p53 and tissue of p53 protein did not differ between the groups. Exogenously administered OLM can effectively prevent the occurrence of esophageal strictures caused by corrosive esophageal burns. (Folia Histochemica et Cytobiologica 2014, Vol. 52, No. 1, 29–35

Desferrioxamine Reduces Oxidative Stress in the Lung Contusion

Our hypothesis in this study is that desferrioxamine (DFX) has therapeutic effects on experimental lung contusions in rats. The rats were divided into four groups (n=8): control, control+DFX, contusion, and contusion+DFX. In the control+DFX and contusion+DFX groups, 100 mg/kg DFX was given intraperitoneally once a day just after the contusion and the day after the contusion. Contusions led to a meaningful rise in the malondialdehyde (MDA) level in lung tissue. MDA levels in the contusion+DFX group experienced a significant decline. Glutathione levels were significantly lower in the contusion group than in the control group and significantly higher in the contusion+DFX group. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels in the contusion group were significantly lower than those in the control group. In the contusion+DFX group, SOD and GPx levels were significantly higher than those in the contusion group. In light microscopic evaluation, the contusion and contusion+DFX groups showed edema, hemorrhage, alveolar destruction, and leukocyte infiltration. However, histological scoring of the contusion+DFX group was significantly more positive than that of the contusion group. The iNOS staining in the contusion group was significantly more intensive than that in all other groups. DFX reduced iNOS staining significantly in comparison to the contusion group. This study showed that DFX reduced oxidative stress in lung contusions in rats and histopathologically ensured the recovery of the lung tissue

Structure and Ion Exchange Behavior of Zirconium Antimonates for Strontium

WOS: 000318354800010Zirconium antimonates with initial Sb:Zr mole ratios of 1.0, 1.5, 4.0, and 9.0 were synthesized by co-precipitation to remove strontium ions from acidic solutions. The characterization of materials was investigated by X-ray diffraction (XRD), Scanning electron microscopy-Energy dispersive X-ray (SEM-EDX), X-ray fluoresence (XRF), and zeta potential analyses. Ion exchange studies of the synthesized materials towards strontium were conducted as a function of contact time and initial pH. Preliminary results reveal that as the antimony ratio increases the surface of the materials become more acidic and thus, strontium exchange is more favorable in a pH range of 2-6

Removal of Ni-63 and Co-57 from aqueous solution using antimony doped tin dioxide-polyacrylonitrile (Sb doped SnO2-PAN) composite ion-exchangers

WOS: 000329299200119Tin dioxide and its antimony doped counterpart were synthesized using traditional sol-gel procedure. The metal oxides were then turned into composites by mixing them with polyacrylonitrile (PAN) and composite spheres ready for use in traditional column applications were obtained. The characterization of materials was investigated by X-ray diffraction, scanning electron microscopy-energy dispersive X-ray, surface area, point of zero charge and thermal analyses. Static batch experiments showed that the antimony doped tin dioxide-PAN (Sb doped SnO2-PAN) is an effective material for nickel removal and the composite maintains its good metal uptake properties in dynamic column conditions. The composite showed a high nickel uptake capacity of 9 mmol/g in 0.1 M NaNO3 solution. It was observed that the ion exchange kinetics of antimony doped tin dioxide (Sb doped SnO2) was remarkably fast for Co-57 and Ni-63 ions but turning the material into PAN composite significantly decreased the materials kinetic properties