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Abstract

Apnea is one of the deadliest diseases that can be prevented and cured if it is detected in time. In this paper, we propose a precise method for early detection of the obstructive sleep apnea (OSA) disease using the latest feature selection and extraction methods. The feature selection in this paper is based on the Dual tree complex wavelet (DT-CWT) coefficients of the ECG signals of several patients. The feature extraction from these coefficients is done using frequency and time techniques. The Feature selection is done using the spectral regression discriminant analysis (SRDA) algorithm and the classification is performed using the hybrid RBF network. A hybrid RBF neural network is introduced in this paper for detecting apnea that is much less computationally demanding than the previously presented SVM networks. Our findings showed a 3 percent improvement in the detection and at least a 30 percent reduction in the computational complexity in comparison with methods that have been presented recently.

Abstract

Nonhuman primates are often used in biomedical research and to investigate physiologic processes that occur in man. Impedance plethysmography was used to measure calf, thigh, pelvic, abdominal, and thoracic volume changes in ten Rhesus and eight squirrel monkeys during five-minute exposures to HUT and HDT at angles of 5, 10, and 20 degrees. Calf, rump and tail measurements were made in three squirrel monkeys at 10 and 20 degrees of HUT and HDT. Fluid volume changes in all segments of the Rhesus monkeys were found to change during HUT an HDT in direct relation to the angle of tilt used. However, the volume changes that occurred in the squirrel monkeys were found to be quite different. Their calf, thigh, and pelvic segments lost volume during both HUT and HDT while their abdominal and thoracic segments responded similarly to those of the Rhesus monkeys. These results and those of the calf/tail measurements of the squirrel monkeys suggest that they may utilize their tails as a compensatory reservoir during postural changes and therefore, may not be an appropriate animal model for man under some orthostatic test conditions.

Abstract

Clustering as a fundamental unsupervised learning is considered an important method of data analysis, and K-means is demonstrably the most popular clustering algorithm. In this paper, we consider clustering on feature space to solve the low efficiency caused in the Big Data clustering by K-means. Different from the traditional methods, the algorithm guaranteed the consistency of the clustering accuracy before and after descending dimension, accelerated K-means when the clustering centeres and distance functions satisfy certain conditions, completely matched in the preprocessing step and clustering step, and improved the efficiency and accuracy. Experimental results have demonstrated the effectiveness of the proposed algorithm.

Abstract

A model for predator-prey interactions with herd behaviour is proposed. Novelty includes a smooth transition from individual behaviour (low number of prey) to herd behaviour (large number of prey). The model is analysed using standard stability and bifurcations techniques. We prove that the system undergoes a Hopf bifurcation as we vary the parameter that represents the efficiency of predators (dependent on the predation rate, for instance), giving rise to sustained oscillations in the system. The proposed model appears to possess more realistic features than the previous approaches while being also relatively easier to analyse and understand.

Abstract

In forests, edaphic microbial communities are involved in litter decomposition and soil forming processes, with major contribution to humification, especially bacteria and fungi being responsible for the main ecosystem services fulfilled by the soil. Research has been carried out aiming to characterize the structure and diversity of microbial communities in the Rendzic Leptosols (WRB) under natural deciduous forest from Visterna, Babadag Plateau and to assess their contribution to ecosystem services provided by soil. The paper presents the results of quantitative estimations and taxonomic composition of soil and litter communities of heterotrophic bacteria and fungi, identification of cellulolytic species, as well as the microbial biomass and global physiological activities expressed as soil respiration potential. More than a half of bacterial species were common in litter and soil (SI=57.14%) and were represented by dominant species of fluorescent or non-fluorescent pseudomonads and Bacillus subtilis but no similarity was found between the two fungal communities. Fungal populations included cosmopolitan species, such as antagonists and strong cellulolytic representatives of genera Penicillium, Trichoderma, Mortierella, Chaetomium, Epicoccum, Aspergillus. Microbial density and microbial biomass presented the highest values in the litter (684 mg C x kg-1 d.s.) and in surface horizon Am1 of soil profile than in the bottom layers. The highest diversity was found in Am1 horizon (0-5 cm) H’=1.983 bits and ε=0.869 for cellulolytic community. Soil respiration reflected the intense physiological activity of microbiome, with high values associated to numerous effectives of bacteria and fungi especially in surface horizon. Microorganisms identified contribute to formation of soil by recycling of nutrients, cellulose decomposition, the synthesis of stable organic matter (humic acids), aggregation of soil particles, biological control of pathogens by antagonistic activity. They improve plant uptake of water and nutrients by forming symbioses (ectomycorrhizae), thus modelling the structure of vegetation.

Abstract

Stressful saline concentrations in soils affect photosynthesis by damaging pigments, photosystems, components of electron transport system, and enzymes involved in the process. Plants respond through very complex stress adaptation mechanisms including proteome modulation, alterations in pigment content, cell osmotic adjustment and control of ion and water homeostasis mechanisms, which stabilize cytosolic glutathione redox potential, etc. The level of plant sensitivity depends on salt toxicity levels, growth stage, physiological and genetic factors. With aim the investigation of the salinity tolerant cultivars, and for the elucidation of mechanisms underlying this complex biological process, here we analyze the impact of four NaCl concentrations (0-50-100-200mM) in growth parameters (root, shoot and leaves length), pigment content (chla, chlb, carotenoids), and GSH content, during seedling of five bread wheat (Triticum aestivum L.) cultivars in modified Hoagland solutions. Based on biometric parameters, pigment synthesis and GSH content cultivar Nogal is salt-sensitive (growth and pigments reduced); cultivar Viktoria is medium-tolerant (growth partially impaired, pigments constant), cultivar Toborzo and cultivar Suba are medium-tolerant (growth partially impaired, pigments increased), cultivar Dajti salt-tolerant (growth partially impaired/ leaves developed, pigments increased). Quantity of GSH in response to different levels of salinity is cultivar specific, and time of exposure to salinity is in negative correlation to GSH content for all investigated cultivars.

Abstract

This study aimed to investigate the effects of possible zinc (Zn) and molybdenum (Mo) contaminations on the critically endangered European Bluestar (Amsonia orientalis). The effects of Zn and Mo were tested in a dose-dependent manner on in vitro cultures. Zn at 0.1 mM in the medium inhibited root development whereas Mo showed the same effect only at ≥2.5 mM concentration. Gradual inhibition of shoot development was observed after treatment with both metals. Protein contents were also negatively affected by increasing metal concentrations, while proline levels increased gradually. Successive increases in metal concentrations resulted in higher hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations. The activity of the antioxidant enzymes, peroxidase (POD) and catalase (CAT), were found to be enhanced in response to increasing metal concentrations. Superoxide dismutase (SOD) activity decreased after Zn treatment but increased after Mo treatment. A marked increase in POD and CAT in response to metal stress suggests that these enzymes might have a significant cooperative role in regulating H2O2 production, although CAT, in response to drought and salt stress, has been reported to only play a supplementary role in A. orientalis. These results indicated that A. orientalis is susceptible to long-term Zn stress but can tolerate up to 2.5 mM Mo in the long-term. Deficiency of Mo is more common than high toxic concentrations in the environment. Therefore Zn contamination should be considered as one of the major threats for A. orientalis in its native habitat.

Abstract

Yarrow essential oil is used in complementary and alternative therapy for several diseases. Biological effects of essential oils span various cells and microorganisms. The aim of this study was to investigate the effects of different concentrations of the essential oil obtained from the yarrow plant (Achillea millefolium) on HeLa (CCL-2) cells. The components of the essential oil were studied by means of GC-MS analysis. Out of 10 determined compounds in the essential oil; 1,8-Cineole, Camphor, Beta-eudesmol and Camphene were found to be higher than others; and their biological effects were depicted with Ingeniuty Pathway Analysis (IPA) analysis. Moreover, cell cycle and proliferation tests were conducted on HeLa cells where yarrow plant’s essential oil was used. When extracted yarrow oil applied on HeLA Cells, apoptotic effects had been determined, furthermore proliferation of these cells decreased. In addition, activation of cell cycle control points was observed . Essential oil components could arrest the development of HeLa cells due to induction of cellular damage control mechanisms. In conclusion, we propose that the essential oil had a more repressive effect on HeLa cells, decreases their proliferation and prevented the increase in the number of cells.

Abstract

The potential use of asparaginases has gained tremendous significance in the treatment of acute lymphoblastic leukemia (ALL). Earlier studies suggest L-asparaginases (L-ASP) extracted from Escherichia coli and Erwinia aroideae regulates L-asparagine (L-Asn) from the circulating blood. Prolonged exposure to these enzymes may lead to hypersensitivity reactions. So, it is important to find novel asparaginases with anti-cancer properties. The three-dimensional structure of L-ASP I from Vibrio campbellii was determined by homology modeling using EasyModeller v.4.0. The structure was validated with quality indexing tools and was deposited in Protein Model DataBase. Molecular docking was performed between L-ASP I and ligand substrate L-Asn to study enzyme-substrate interactions. Qualitative and quantitative analysis of L-ASP I enzyme was found to be reliable and stable with a significant protein quality factor (LG score: 7.129). The enzyme is a dimer, belongs to α/β class of proteins. The active sites comprises of N-glycosylation site and a catalytic triad (T14-S117-D92). The binding energy of the docked complex was calculated to be -7.45 kcal/mol. The amino acid T14 identified as a primary nucleophile essential for catalytic reaction. The enzyme L-ASP I of V. campbellii provides a detailed view of structure and functional aspects with ligand substrate L-Asn. This in silico investigation has explicitly demonstrated for the first time that cytosolic L-ASP Type I of V. campbellii to have a catalytic triad which was attributed only to periplasmic L-ASP Type II. Thus, L-ASP I can serve as anti-leukemic agent in the treatment, management and control of ALL.