Differential fast fixed-point algorithms for underdetermined instantaneous and convolutive partial blind source separation

This paper concerns underdetermined linear instantaneous and convolutive blind source separation (BSS), i.e., the case when the number of observed mixed signals is lower than the number of sources.We propose partial BSS methods, which separate supposedly nonstationary sources of interest (while keeping residual components for the other, supposedly stationary, "noise" sources). These methods are based on the general differential BSS concept that we introduced before. In the instantaneous case, the approach proposed in this paper consists of a differential extension of the FastICA method (which does not apply to underdetermined mixtures). In the convolutive case, we extend our recent time-domain fast fixed-point C-FICA algorithm to underdetermined mixtures. Both proposed approaches thus keep the attractive features of the FastICA and C-FICA methods. Our approaches are based on differential sphering processes, followed by the optimization of the differential nonnormalized kurtosis that we introduce in this paper. Experimental tests show that these differential algorithms are much more robust to noise sources than the standard FastICA and C-FICA algorithms.Comment: this paper describes our differential FastICA-like algorithms for linear instantaneous and convolutive underdetermined mixture

The similarity of astrocytes number in dentate gyrus and CA3 subfield of rats hippocampus

The dentate gyrus is a part of hippocampal formation that it contains granule cells, which project to the pyramidal cells and interneurons of the CA3 subfield of the hippocampus. Astrocytes play a more active role in neuronal activity, including regulating ion flux currents, energy production, neurotransmitter release and synaptogenesis. Astrocytes are the only cells in the brain that contain the energy molecule glycogen. The close relationship between dentate gyrus and CA3 area can cause the similarity of the number of astrocytes in these areas. In this study 5 male albino wistar rats were used. Rats were housed in large plastic cage in animal house and were maintained under standard conditions, after histological processing, The 7 μm slides of the brains were stained with PTAH staining for showing the astrocytes. This staining is specialized for astrocytes. We showed that the number of astrocytes in different (ant., mid., post) parts of dentate gyrus and CA3 of hippocampus is the same. For example, the anterior parts of two area have the most number of astrocytes and the middle parts of two area have the least number of astrocytes. We concluded that dentate gyrus and CA3 area of hippocampus have the same group of astrocytes. © 2007 Asian Network For Scientific Information

The effect of spatial learning on the number of astrocytes in rat dentate gyrus

In this study, we evaluated the effect of spatial learning on the number of astrocytes in the rat dentate gyrus with Morris water maze. Fifteen male albino Wistar rats were divided into three groups as control, reference memory and working memory groups. Each group was consisted of 5 rats. After spatial learning, the brains were histologically examined; the slides were stained with phosphotungstic acid hematoxylin (PTAH) staining to show the astrocytes. We found significant difference in the number of astrocytes in dentate gyrus between control and reference memory groups, and between control and working memory groups as well. When compared two learning groups there was a significant difference in the number of astrocytes between them, being higher in the working memory group. We concluded that the number of astrocytes increased due to spatial learning and this increase can be affected to the period of learning. Our studies of spatial learning and effect of learning techniques (reference and working memory) showed that the technique that has longer period of learning has more effect on the number of astrocytes

The effect of spatial learning on the number of astrocytes in the CA3 subfield of the rat hippocampus

Introduction: Astrocytes play an important role in the hippocampus, probably in memory and learning. The aim of this study was to evaluate the number of astrocytes in the CA3 subfield of the rat hippocampus after spatial learning using the Morris water maze with reference and working memory methods. Methods: 45 male albino wistar rats were divided into three groups, with 15 rats in the control group and 15 rats in each of the other two groups. The two study groups of rats underwent spatial learning using the Morris water maze, with one group trained using the reference memory and the other, the working memory technique, respectively. After histological processing, the slides of the brains were stained with the phosphotanguestic acid haematoxylin staining method for detection of the astrocytes. Results: There was a significant difference in the number of astrocytes in the CA3 area between the control and reference memory groups. The difference between control and working memory groups was significant as well. Additionally, when comparing the two learning groups, we also found significant differences between them. Conclusion: The number of astrocytes increased due to spatial learning

Water disinfection using photocatalytic process with titanium dioxide nanoparticles

Background and purpose: Disinfection is one of the most important stages in water treatment. So far, various chemical disinfection methods such as chlorination have been widely used. However, these methods have serious disadvantages, like producing DBPs. The purpose of this research was to study the efficacy of nTiO2 photocatalyst process on removing E.Coli as a water microbial pollution index and effects of some parameters on its efficiency. Materials and methods: Water was artificially contaminated with E.Coli. Culture method and counting were performed according to standard methods for water and wastewater and was reported as CFU/ml. The size of nTiO2 was 20 nm that was used in the presence or absence of UV for disinfection. The Kolmogorov-Smirnov Test was used to check the normality of the data. The ANOVA and T-Test were used for analyzing the data. Results: The results indicated that the inactivation of Escherichia coli increased with increase of nTiO2 catalyst dose and contact time. However, the efficiency decreased when the number of colonies increased. Minimum, average and maximum percentage removal of nTiO2+UV process were 75.1, 88.9±12.7, and 100%, respectively, in 40 min contact time and 0.8 g/L catalyst dose. Conclusion: The bacteria mortality rate in the presence of UV alone was more than that of the nTiO2 alone process. However, the efficiency of the photocatalytic process (UV+nTiO2) was more than that of the UV alone or nTiO2 alone. © 2015, Mazandaran University of Medical Sciences. All rights reserved

Estimation of astrocyte number in different subfield of rat hippocampus

The hippocampal formation is present in all mammalian species and it is consist of the subiculum, the hippocampus and the dentate gyrus. Apart from principal neurons, the hippocampal formation contains glial cells and various types of intemeurons. Glial cells in hippocampus contains the Astrocytes, microglia and oligodantrocytes. Astrocytes play a more active role in neuronal activity, including regulating ion flux currents, energy production, neurotransmitter release and synaptogenesis. Astrocytes are the only cells in the brain that contain the energy molecule glycogen. In this study 5 male albino wistar rats were used. After histological processing. The slides of the brains were stained with PTAH staining for showing the astrocytes. We showed differences in number of astrocytes in different compartment of hippocampus. There is significant difference between CA1 and CA3 and also between CA2 and CA3 areas. We concluded that functional differences can due to structural differences. © 2006 Asian Network for Scientific Information

Vasopressin attenuates ischemia-reperfusion injury via reduction of oxidative stress and inhibition of mitochondrial permeability transition pore opening in rat hearts

Aim of this study was to investigate the involvement of the mitochondrial permeability transition pore (MPTP) and oxidative stress in the cardioprotective effect of vasopressin (AVP) on ischemia/reperfusion (I/R) injury. Anesthetized male wistar rats were subjected to regional 30 min ischemia and 120 min reperfusion and randomly divided into nine groups: (1) Control; saline was administered intravenously before ischemia, (2) vasopressin was administrated 10 min prior to ischemia, (3, 4) Atractyloside as MPTP opener, was injected 5 min prior to reperfusion without and with vasopressin, (5, 6) Cyclosporine A as a MPTP closer, was injected 5 min prior to reperfusion without and with vasopressin, (7) mitochondria were isolated from control group and CaCl2 was added as MPTP opener and swelling inducer, (8) isolated mitochondria from Control hearts was incubated with Cyclosporine A before adding the CaCl2 (9) CaCl2 was added to isolated mitochondria from vasopressin group. Infusion of vasopressin decreased infarct size (18.6±1.7% vs. control group 37.6±2.4%), biochemical parameters [LDH (Lactate Dehydrogenase), CK-MB (Creatine Kinase-MB) and MDA (Malondialdehyde) plasma levels, PAB (Prooxidant-antioxidant balance)] compared to control group. Atactyloside suppressed the cardioprotective effect of vasopressin (32.5±1.9% vs. 18.6±1.7%) but administration of the Cyclosporine A without and with vasopressin significantly reduced infarct size to 17.7±4% (P<0.001) and 22.7±3% (P<0.01) respectively, vs. 37.6±2.4% in control group. Also, vasopressin, similar to Cyclosporine A, led to decrease in CaCl2-induced swelling. It seems that vasopressin through antioxidant effect and MPTP inhibition has created a cardioprotection against ischemia/reperfusion injuries. © 2015 Elsevier B.V. All rights reserved

Monitoring hydroperoxides formation as a measure of predicting walnut oxidative stability

It is believed that lipids are the most important factor affecting nuts shelf-life. In the present study, an accelerated shelf-life testing by means of elevated temperatures 62, 72, and 82 °C was conducted to predict the oxidation stability of walnuts over a long-term storage. Peroxide value (PV) was employed to monitor the lipid oxidation progression in the walnuts. A range of 74.01–79.57 kJ mol−1 K−1 energy was required for formation of primary oxidation products. The reaction changes followed an apparent first-order kinetic. Formation of hydroperoxides in walnut kernels was found to be a temperature-dependent reaction with Q10 of 2.1. Walnut kernels were also kept in normal condition (temp: 20–30 °C; relative humidity (RH): 35–45%) for 12 months to validate the shelf-life estimation approach. The results showed that PV could provide a proper estimation for oxidative stability of the walnuts stored in ordinary condition