Classification of electrocardiogram signals with support vector machines and genetic algorithms using power spectral features

This paper proposes a new power spectral-based hybrid genetic algorithm-support vector machines (SVMGA) technique to classify five types of electrocardiogram (ECG) beats, namely normal beats and four manifestations of heart arrhythmia. This method employs three modules: a feature extraction module, a classification module and an optimization module. Feature extraction module extracts electrocardiogram's spectral and three timing interval features. Non-parametric power spectral density (PSD) estimation methods are used to extract spectral features. Support vector machine (SVM) is employed as a classifier to recognize the ECG beats. We investigate and compare two such classification approaches. First they are specified experimentally by the trial and error method. In the second technique the approach optimizes the relevant parameters through an intelligent algorithm. These parameters are: Gaussian radial basis function (GRBF) kernel parameter σ and C penalty parameter of SVM classifier. Then their performances in classification of ECG signals are evaluated for eight files obtained from the MIT–BIH arrhythmia database. Classification accuracy of the SVMGA approach proves superior to that of the SVM which has constant and manually extracted parameter.     

Antihemolytic and antioxidant activities of <Emphasis Type="Italic">Allium paradoxum</Emphasis>

Antioxidant activity of the aerial part and bulbs of Allium paradoxum was investigated by eight in vitro assay systems. Extracts showed good antioxidant activity. IC₅₀ for 1,1-diphenyl-2-picryl hydrazyl radical-scavenging activity was 890.9±43.2 and 984.9±33.5 μg/ml for the aerial part and bulbs, respectively. The aerial parts have better reducing power than bulb extracts but not comparable with Vitamin C (P>0.001). Extracts showed weak Fe²⁺ chelating ability, the IC₅₀ being 959±47 and 530±24 μg/ml for bulbs and aerial parts, respectively. Both tested extracts exhibited good hydrogen peroxide scavenging in a concentration dependent manner. They exhibited good antioxidant activity against the hemoglobin-induced linoleic acid system that was comparable with vitamin C (P>0.01). They showed good activity against cumene hydro peroxide induced hemolysis in RBCs. In addition, they possessed antihemolytic activity. The extract from aerial parts had significantly higher total phenol and flavonoid content than did bulbs. Amounts of eight elements (Cu, Mn, Zn, Fe, Ni, Pb, Cd and Cr) were also determined in the bulb and aerial part using atomic absorption spectroscopy. They contained higher Fe and Mn contents than other elements.     

Expression analysis of dehydrin multigene family across tolerant and susceptible barley (Hordeum vulgare L.) genotypes in response to terminal drought stress

Dehydrins are one of the characteristic families of plant proteins that usually accumulate in response to drought. In the present study, gene expressions of dehydrin multigene family (13 genes) were examined in flag leaves of tolerant (Yousef) and susceptible (Moroco) barley varieties under terminal drought to characterize the involvement of dehydrins in the adaptive processes. The stomatal conductance, RWC, and Chl a, b contents had more reduction in Moroco than the Yousef which has more elevated osmotic adjustment. Drought stress increased significantly MDA and electrolyte leakage levels, but greater in Moroco, indicating a poor protection of cell and cytoplasmic membrane in this variety. Yousef variety had no reduction in grain yield under drought condition. Five genes (Dhn1, Dhn3, Dhn5, Dhn7 and Dhn9) were exclusively induced in Yousef under drought stress. In the stress condition, relative gene expression of Dhn3, Dhn9 had the direct correlations (P < 0.05) with Chl a, b contents, osmotic adjustment, stomatal conductance, plant biomass and grain yield, and the negative correlations (P < 0.05) with MDA and electrolyte leakage levels. The results supported the impending functional roles of dehydrin K_n and particularly Y_nSK_n types in dehydration tolerance of barley during the reproductive stage.     

High rate of detection of mixed infections of Plasmodium vivax and Plasmodium falciparum in South-East of Iran, using nested PCR

Sistan and Baluchestan province, South-East of Iran, has been reported as an endemic area of malaria [Sadrizadeh B. Malaria in the world, in the eastern Mediterranean region and in Iran: Review article. WHO/EMRO Report 2001: 1-13.]. The main objective of this research was to perform rapid and correct diagnoses of malaria infection. Blood specimens were collected from 140 suspected volunteers. The Giemsa-stained slides examination and nested PCR for amplification of the Plasmodium small subunit ribosomal genes (ssrRNA) were utilized. The results demonstrated 118 out of 140 cases (84.3%) positive for malaria parasites, including 60.7%, 20.7% and 2.9% as having Plasmodium vivax (P.v), Plasmodium falciparum (P.f) and mixed infections (P.v+P.f), respectively by microscopy. The nested PCR detected malaria parasites in 134 samples (94.3%), consisting of 51.4% P.v, 12.6% P.f and 29.3% mixed infections. The PCR analysis detected 37 cases of mixed infections more than that of the routine microscopy. These results suggested that there are a considerable number of cases with mixed infections in the study area that mainly remain undiagnosed by microscopy. It is also concluded that the nested PCR is a suitable complement to microscopy for accurate specific diagnosis of malaria species in field.     

Preparation of Polyamide Nanocapsules of Aloe vera L. Delivery with In Vivo Studies

Aloe vera is the oldest medicinal plant ever known and the most applied medicinal plant worldwide. The purpose of this study was to prepare polyamide nanocapsules containing A. vera L. by an emulsion diffusion technique with in vivo studies. Diethyletriamine (DETA) was used as the encapsulating polymer with acetone ethyl acetate and dimethyl sulfoxide (DMSO) as the organic solvents and Tween and gelatin in water as the stabilizers. Sebacoyl chloride (SC) monomer, A. vera L. extract, and olive oil were mixed with the acetone and then water containing DETA monomer was added to the solution using a magnetic stirrer. Finally, the acetone was removed under vacuum, and nanocapsules were obtained using a freeze drier. This study showed that the size of the nanocapsule depends on a variety of factors such as the ratio of polymer to oil, the concentration of polymers, and the plant extract. The first sample is without surfactant and the size of nanocapsules in the sample is 115 nm. By adding surfactant, nanocapsules size was reduced to 96 nm. Nanocapsules containing A. vera were administered to rats and the effects were compared with a normal control group. The results showed that in the A. vera group, the effect is higher. The nanocapsules were identified by scanning electron microscopy (SEM), zeta potential sizer (ZPS), and Fourier-transform infrared spectroscopy (FT-IR).KEY WORDS: Aloe vera L., in vivo, medicinal plant, nanocapsule, polyamide nanocapsule     

Identification of differentially accumulated proteins associated with embryogenic and non-embryogenic calli in saffron (Crocus sativus L.)

Background

Somatic embryogenesis (SE) is a complex biological process that occurs under inductive conditions and causes fully differentiated cells to be reprogrammed to an embryo like state. In order to get a better insight about molecular basis of the SE in Crocus sativus L. and to characterize differentially accumulated proteins during the process, a proteomic study based on two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry has been carried out.

Results

We have compared proteome profiles of non-embryogenic and embryogenic calli with native corm explants. Total soluble proteins were phenol-extracted and loaded on 18 cm IPG strips for the first dimension and 11.5% sodium dodecyl sulfate-polyacrylamide gels for the second dimension. Fifty spots with more than 1.5-fold change in abundance were subjected to mass spectrometry analysis for further characterization. Among them 36 proteins could be identified, which are classified into defense and stress response, protein synthesis and processing, carbohydrate and energy metabolism, secondary metabolism, and nitrogen metabolism.

Conclusion

Our results showed that diverse cellular and molecular processes were affected during somatic to embryogenic transition. Differential proteomic analysis suggests a key role for ascorbate metabolism during early stage of SE, and points to the possible role of ascorbate-glutathione cycle in establishing somatic embryos.     

The effect of PTZ-induced epileptic seizures on hippocampal expression of PSA-NCAM in offspring born to kindled rats

Background

Maternal epileptic seizures during pregnancy can affect the hippocampal neurons in the offspring. The polysialylated neural cell adhesion molecule (PSA-NCAM), which is expressed in the developing central nervous system, may play important roles in neuronal migration, synaptogenesis, and axonal outgrowth. This study was designed to assess the effects of kindling either with or without maternal seizures on hippocampal PSA-NCAM expression in rat offspring.

Methods

Forty timed-pregnant Wistar rats were divided into four groups: A) Kind⁺/Seiz⁺, pregnant kindled (induced two weeks prior to pregnancy) rats that received repeated intraperitoneal (i.p.) pentylenetetrazol, PTZ injections on gestational days (GD) 14-19; B) Kind^-/Seiz⁺, pregnant non-kindled rats that received PTZ injections on GD14-GD19; C) Kind⁺/Seiz^-, pregnant kindled rats that did not receive any PTZ injections; and D) Kind^-/Seiz^-, the sham controls. Following birth, the pups were sacrificed on PD1 and PD14, and PSA-NCAM expression and localization in neonates’ hippocampi were analyzed by Western blots and immunohistochemistry.

Results

Our data show a significant down regulation of hippocampal PSA-NCAM expression in the offspring of Kind⁺/Seiz⁺ (p = 0.001) and Kind^-/Seiz⁺ (p = 0.001) groups compared to the sham control group. The PSA-NCAM immunoreactivity was markedly decreased in all parts of the hippocampus, especially in the CA3 region, in Kind⁺/Seiz⁺ (p = 0.007) and Kind^-/Seiz⁺ (p = 0.007) group’s newborns on both PD1 and 14.

Conclusion

Our findings demonstrate that maternal seizures but not kindling influence the expression of PSA-NCAM in the offspring’s hippocampi, which may be considered as a factor for learning/memory and cognitive impairments reported in children born to epileptic mothers.     

Theoretical investigation of the use of nanocages with an adsorbed halogen atom as anode materials in metal-ion batteries

The applicability of C₄₄, B₂₂N₂₂, Ge₄₄, and Al₂₂P₂₂ nanocages, as well as variants of those nanocages with an adsorbed halogen atom, as high-performance anode materials in Li-ion, Na-ion, and K-ion batteries was investigated theoretically via density functional theory. The results obtained indicate that, among the nanocages with no adsorbed halogen atom, Al₂₂P₂₂ would be the best candidate for a novel anode material for use in metal-ion batteries. Calculations also suggest that K-ion batteries which utilize these nanocages as anode materials would give better performance and would yield higher cell voltages than the corresponding Li-ion and Na-ion batteries with nanocage-based anodes. Also, the results for the nanocages with an adsorbed halogen atom imply that employing them as anode materials would lead to higher cell voltages and better metal-ion battery performance than if the nanocages with no adsorbed halogen atom were to be used as anode materials instead. Results further implied that nanocages with an adsorbed F atom would give higher cell voltages and better battery performance than nanocages with an adsorbed Cl or Br atom. We were ultimately able to conclude that a K-ion battery that utilized Al₂₁P₂₂ with an adsorbed F atom as its anode material would afford the best metal-ion battery performance; we therefore propose this as a novel highly efficient metal-ion battery.

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Graphical abstract The results of a theoretical investigation indicated that Al₂₂P₂₂ is a better candidate for a high-performance anode material in metal-ion batteries than Ge₄₄ is. Calculations also showed that K-ion batteries with nanocage-based anodes would produce higher cell voltages and perform better than the equivalent Li-ion and Na-ion batteries with nanocage-based anodes, and that anodes based on nanocages with an adsorbed F atom would perform better than anodes based on nanocages with an adsorbed Cl or Br atom

     

Plantlet regeneration from protoplast-derived embryogenic calli of Crocus cancellatus

Plant regeneration from protoplast culture of Crocus cancellatus was investigated using regenerable embryogenic calli obtained from shoot meristem culture on LS (Linsmaier and Skoog, 1965) medium containing 4 mg l⁻¹ kinetin and 1 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D). Protoplasts were isolated directly from embryogenic calli. The best protoplast growth was found on those embedded in Ca-alginate beads and cultured with nurse cells in MS (Murashige and Skoog, 1962) medium supplemented with 2 mg l⁻¹ kinetin, 1 mg l⁻¹ 2,4-D and 100 mg l⁻¹ ascorbic acid at 25 °C in darkness. After 4–5 weeks of culture, microcalli appeared on the surface of the Ca-alginate beads, but the protoplasts without immobilization in Ca-alginate beads showed very low cell division. Growth of the microcalli in the medium with nurse cells was much better than in the medium without nurse cells. Transferring beads onto half strength MS medium supplemented with 0.2 mg l⁻¹ kinetin and 0.1 mg l⁻¹ 2,4-D, increased the growth of embryogenic calli. Somatic embryo development was observed either on half strength MS medium growth regulator free or with 1 mg l⁻¹ abscisic acid. Matured embryos germinated on half strength MS medium containing 25 mg l⁻¹ of gibberelic acid. Plantlet formation was obtained on half strength MS medium containing 1 mg l⁻¹ 6-benzyladenine and 1 mg l⁻¹ α-naphthaleneacetic acid at 20 °C in a 16/8 h light/dark cycle. This revised version was published online in June 2006 with corrections to the Cover Date.     

CO2 biofixation and fatty acid composition of two indigenous Dunaliella sp. isolates (ABRIINW-CH2 and ABRIINW-SH33) in response to extremely high CO2 levels

Bioprocess and Biosystems Engineering - Global warming, as a result of atmospheric CO2 increase, is regarded as an important universal concern. Microalgae are considered as appropriate...