Diagnosis of attention deficit hyperactivity disorder using non‐linear analysis of the EEG signal

Attention deficit hyperactivity disorder (ADHD) is a common behavioural disorder that may be found in 5%–8% of the children. Early diagnosis of ADHD is crucial for treating the disease and reducing its harmful effects on education, employment, relationships, and life quality. On the other hand, non‐linear analysis methods are widely applied in processing the electroencephalogram (EEG) signals. It has been proved that the brain neuronal activity and its related EEG signals have chaotic behaviour. Hence, chaotic indices can be employed to classify the EEG signals. In this study, a new approach is proposed based on the combination of some non‐linear features to distinguish ADHD from normal children. Lyapunov exponent, fractal dimension, correlation dimension and sample, fuzzy and approximate entropies are the non‐linear extracted features. For computing, the chaotic time series of obtained EEG in the brain frontal lobe (FP1, FP2, F3, F4, and Fz) need to be analysed. Experiments on a set of EEG signal obtained from 50 ADHD and 26 normal cases yielded a sensitivity, specificity, and accuracy of 98, 92.31, and 96.05%, respectively. The obtained accuracy provides a significant improvement in comparison to the other similar studies in identifying and classifying children with ADHD.Inspec keywords: feature extraction, time series, fractals, electroencephalography, medical disorders, neurophysiology, medical signal processing, entropy, signal classification, Lyapunov methodsOther keywords: nonlinear extracted features, chaotic time series, identifying classifying children, attention deficit hyperactivity disorder, nonlinear analysis methods, electroencephalogram signals, brain neuronal activity, chaotic behaviour, chaotic indices, EEG signals, nonlinear features, approximate entropies, common behavioural disorder, early diagnosis, life quality, ADHD     

SYNERGISTIC EFFECTS OF ANIONIC SURFACTANT AND NONIONIC POLYMER ADDITIVES ON DRAG REDUCTION

Turbulent drag reduction (DR) behavior of mixed nonionic polymer and anionic surfactant solutions in water was studied in a pipeline set up to explore the synergic effects of mixed additives on DR. The concentration of polymer polyethylene oxide (PEO) was varied from 0 to 2000 ppm and the concentration of surfactant sodium dodecyl sulfate (SDS) was varied from 0 to 5000 ppm. The critical aggregation concentration (CAC), where the interaction between the polymer and the surfactant begins, and the polymer saturation point (PSP), where the polymer molecules become saturated with the surfactant, were determined using electrical conductivity and surface tension measurements. As the polymer concentration was increased the CAC decreased but the PSP increased. The relative viscosity showed a remarkable increase upon the addition of surfactant to the polymer solution due to extension of polymer chains caused by the formation of micelles on the backbone of the polymer molecules. The data exhibited a considerable increase in DR in the case of mixed polymer/surfactant systems. The percent reduction in friction factor was as high as 79 when 3000 ppm or more surfactant was added to the 500 ppm polymer solution. Furthermore, the drag reduction behavior of the polymer solution changed from so-called Type A to Type B. In Type A drag reduction, a transition from laminar to turbulent regime is observed with a clear-cut onset point. In Type B drag reduction, no transition or onset point is observed; the data fall on a gradual extension of the laminar line.     

Development and Use of Quantitative Competitive PCR Assay for Detection of Poultry DNA in Sausage

This study focused on the development and evaluation of a quantitative competitive polymerase chain reaction (QC-PCR) for detection and quantification of poultry DNA in sausage. PCR is well known to be quantitative if internal DNA standards are co-amplified together with the target DNA. A DNA competitor differing by 83 bp in length from the poultry target sequence was constructed and used for PCR together with the target DNA. Specificity of the new primers was evaluated with DNA from cattle and sheep. The results of QC-PCR showed that the percentage of contamination was in the range of 23.87–52.06%.     

Predicting the stages of smoking acquisition in the male students of Shiraz's high schools, 2003.

A staged model of smoking adoption has been widely applied in studies of adolescent smoking. This paper examined the effects of socioenvironmental and personal factors on three stages of the smoking continuum among a sample of 10th-grade male students, ages 14-19 years, at 20 high schools in Shiraz city. This paper is the first step of a longitudinal study related to adolescents smoking and predictors of transition in the stages. A self-administered questionnaire was distributed to 1,132 10th-grade students from a possible population of 14,000 students. Multivariate discriminant function analysis was used to analyze the data. Overall 19.4% of students had smoked; 80.6%, 16.9%, and 2.5% had never smoked, had experimented, and had regularly smoked, respectively. The discriminant function analysis indicated that attitude toward smoking, use of alcohol, use of illicit drugs, smoking behavior of best friends, and self-esteem were related to more intense smoking behaviors. Finally, these variables permitted the correct classification of 70.3% of students into the stages of smoking acquisition. This finding has important public health significance, but further research is required to determine if the association is causal.     

Effects of UVB on the synthesis of complement proteins by keratinocytes

Conditioned taste aversion is a common classic conditioning procedure used to identify noxious stimuli. When a rat is given a taste solution, the conditioned stimulus (CS), followed by an unpleasant experience, the unconditioned stimulus (US), the rat will avoid consumption of the CS in future presentations. These experiments use the taste aversion procedure to examine the effect of exposure to a high magnetic field. A solution consisting of 3.0 g glucose and 1.25 g saccharin per 1 L of solution (G+S) was used as the CS and a 9.4-T magnet served as the US. In Experiment 1, all rats received a 10 min presentation of the G+S solution followed by either a 30 min exposure to the magnetic field (Magnet, n = 8), a 30-min exposure in a container with similar conditions but lacking the magnetic field (Sham, n = 8), or no exposure (Control, n = 8). The Magnet Group showed a taste aversion on the first day of preference testing (p < 0.05). Experiment 2 employed the same US-CS protocol for 3 consecutive days of conditioning. The Magnet Group demonstrated a taste aversion for the postexposure Days 1-8 (p < 0.01). There was no difference between the Sham and Control Groups in either experiment. The results of this study clearly demonstrate that the rats associated the G+S solution with the experience of being exposed to the high magnetic field and avoided the solution in subsequent presentations.     

Post-mortem stimulation of carcasses: effects on biochemistry, biophysics, microbiology, and quality of meat

The influence of post-mortem electrical stimulation of carcasses on the physicochemical, ultrastructural, microbiological, and quality characteristics of meat have been described at length. The latest views, based on the physiological, biochemical, and mechanical models that have been extended to explain the development of tension (contraction) in muscle are presented. The mechanisms by which electrical stimulation causes improvement in certain quality characteristics of meat are considered with some new thoughts. The significance of the mode of electrical flow through the carcass and how the various electrical parameters (electrode-carcass contact, type of current, voltage, pulse characteristics) affect the rate of glycolysis have been explained. The commercial implications of electrical stimulation in the meat industry are highlighted giving special emphasis to hot-boning, energy conservation, and operator safety.     

The mechanism for the promotion of tenderness in meat during the post‐mortem process: A review

The post‐mortem changes in the chemical composition and structure of striated muscle have been reviewed on the basis of various concepts that emerged from the studies of different investigators to explain the course of tenderization of meat during aging. These concepts include the changes in the sarcoplasmic proteins, myofibrillar proteins (such as complete dissociation of actomyosin, partial dissociation of actomyosin, cleavage of disulfide linkages, depolymerization of F‐actin filaments, cleavage of myosin filaments, disorganization of Z‐bands and the troponin‐tropomyosin complex), sarcolemma, connective tissue elements (collagen fibrils, ground substance), and the protein‐ion relationship of the muscle cells (more strictly, syncy‐tia). The experimental evidence for and against each of the views is discussed critically in the light of certain fundamentals of biophysical chemistry and biochemistry. Finally, an alternative hypothesis has been presented based on the differential effect of the post‐mortem formation of lactic acid (H⁺ ion concentration) on the intra‐ and extracellular components of muscle and the possible role of lysosomal cathepsins. Consequently, a series of biophysical, biochemical, and ultrastructural changes seem to account for the mechanism by which meat becomes tender during the aging process.     

Influence of the Ethylene Glycol, Water Treatment and Microwave Irradiation on the Characteristics and Performance of VPO Catalysts for n-Butane Oxidation to Maleic Anhydride

In this paper, the preparation of vanadium phosphate catalysts was shown to be improved by (1) using V₂O₅ and ethylene glycol as starting and reducing agent material, respectively for VOPO₄ · 2H₂O, (2) subsequent water treatment and (3) microwave irradiation. In particular, the preparation route, based on the reduction of VOPO₄ · 2H₂O with various alcohols, is described in detail and contrasted with other three established methods performed by using ethylene glycol and isobutyl alcohol as reductant and solvent for V₂O₅ or distilled water as a solvent material. The preparation of catalyst precursor is carried out by two different methods, namely conventional heating and microwave irradiation. With this new technique, catalysts derived from the reduction of VOPO₄ · 2H₂O by ethylene glycol exhibit substantially higher surface area (typically >40 m² g^?1) and activity. In fact, the surface area of the catalyst is significantly enhanced when the precursor is refluxed by distilled water and dried by microwave heating. The characterization of catalysts was carried out using X-ray diffraction (XRD), Brunauer–Emmer–Teller (BET) surface area measurement, temperature programmed reduction (H₂-TPR), temperature-programmed reaction (TPRn) and scanning electron microscopy (SEM). This study shows that employing ethylene glycol as reducing agent, followed by adding the water treatment step to catalyst synthesis procedure, and using microwave irradiation would give rise to enhanced surface area, activity and selectivity of the catalyst. Moreover, it introduces a more energy efficient procedure for preparation of vanadium phosphate catalyst used in selective oxidation of n-butane process.