A Sound Quality Objective Evaluation Method Based on Auditory Peripheral Simulation Model

##正## Based on auditory peripheral simulation model, a new Sound Quality Objective Evaluation (SQOE) method is presented,which can be used to model and analyze the impacts of head, shoulder and other parts of human body on sound wave trans-mission.This method employs the artificial head technique, in which the head related transfer function was taken into account tothe outer ear simulation phase.First, a bionic artificial head was designed as the outer ear model with considering the outersound field in view of theory and physical explanations.Then the auditory peripheral simulation model was built, which mimicsthe physiological functions of the human hearing, simulating the acoustic signal transfer process and conversion mechanismsfrom the free field to the peripheral auditory system.Finally, performance comparison was made between the proposed SQOEmethod and ArtemiS software, and the verifications of subjective and objective related analysis were made.Results show thatthe proposed method was economical, simple, and with good evaluation quality.     

Analysis and classification of compressed EMG signals by wavelet transform via alternative neural networks algorithms

We propose intelligent methods for classifying three different muscle types, i.e. biceps, frontallis and abductor pollicis brevis muscles, with low computational complexity. For this aim, electromyogram (EMG) signals are recorded and modelled by using an auto-regressive (AR) model. As the size of the EMG signals is usually large, the computational complexity of artificial neural network (ANN) systems drastically increases. Therefore, in the proposed scheme EMG signals are pre-processed by using a wavelet transform and then they are modelled by employing an AR approach. The AR coefficients are used to train and test the ANNs. Experimental results show that the highest achieved classification accuracy is more than 95% in the case of EMG signals pre-processed by wavelet transform. The wavelet transform-based pre-processing significantly increases the performance rates compared to standard multilayer perceptron and general regression neural networks algorithms.     

A Neural Network Model of Chemotaxis Predicts Functions of Synaptic Connections in the Nematode Caenorhabditis elegans

The anatomical connectivity of the nervous system of the nematode Caenorhabditis elegans has been almost completely described, but determination of the neurophysiological basis of behavior in this system is just beginning. Here we used an optimization algorithm to search for patterns of connectivity sufficient to compute the sensorimotor transformation underlying C. elegans chemotaxis, a simple form of spatial orientation behavior in which turning probability is modulated by the rate of change of chemical concentration. Optimization produced differentiator networks capable of simulating chemotaxis. A surprising feature of these networks was inhibitory feedback connections on all neurons. Further analysis showed that feedback regulates the latency between sensory input and behavior. Common patterns of connectivity between the model and biological networks suggest new functions for previously identified connections in the C. elegans nervous system.     

Membrane Potential Fluctuations Determine the Precision of Spike Timing and Synchronous Activity: A Model Study

It is much debated on what time scale information is encoded by neuronal spike activity. With a phenomenological model that transforms time-dependent membrane potential fluctuations into spike trains, we investigate constraints for the timing of spikes and for synchronous activity of neurons with common input. The model of spike generation has a variable threshold that depends on the time elapsed since the previous action potential and on the preceding membrane potential changes. To ensure that the model operates in a biologically meaningful range, the model was adjusted to fit the responses of a fly visual interneuron to motion stimuli. The dependence of spike timing on the membrane potential dynamics was analyzed. Fast membrane potential fluctuations are needed to trigger spikes with a high temporal precision. Slow fluctuations lead to spike activity with a rate about proportional to the membrane potential. Thus, for a given level of stochastic input, the frequency range of membrane potential fluctuations induced by a stimulus determines whether a neuron can use a rate code or a temporal code. The relationship between the steepness of membrane potential fluctuations and the timing of spikes has also implications for synchronous activity in neurons with common input. Fast membrane potential changes must be shared by the neurons to produce synchronous activity.     

A Conceptual Model of Natural and Anthropogenic Drivers and Their Influence on the Prince William Sound,Alaska, Ecosystem

Prince William Sound (PWS) is a semi-enclosed fjord estuary on the coast of Alaska adjoining the northern Gulf of Alaska (GOA). PWS is highly productive and diverse, with primary productivity strongly coupled to nutrient dynamics driven by variability in the climate and oceanography of the GOA and North Pacific Ocean. The pelagic and nearshore primary productivity supports a complex and diverse trophic structure, including large populations of forage and large fish that support many species of marine birds and mammals. High intra-annual, inter-annual, and interdecadal variability in climatic and oceanographic processes as drives high variability in the biological populations. A risk-based conceptual ecosystem model (CEM) is presented describing the natural processes, anthropogenic drivers, and resultant stressors that affect PWS, including stressors caused by the Great Alaska Earthquake of 1964 and the Exxon Valdez oil spill of 1989. A trophodynamic model incorporating PWS valued ecosystem components is integrated into the CEM. By representing the relative strengths of driver/stressors/effects, the CEM graphically demonstrates the fundamental dynamics of the PWS ecosystem, the natural forces that control the ecological condition of the Sound, and the relative contribution of natural processes and human activities to the health of the ecosystem. The CEM illustrates the dominance of natural processes in shaping the structure and functioning of the GOA and PWS ecosystems.     

A Mathematical Model of the Human Circadian System and Its Application to Jet Lag

A mathematical model of the circadian system is described that is appropriate for application to jet lag. The core of the model is a van der Pol equation with an external force. Approximate solutions of this equation in which the external force is composed of a constant and an oscillating term are investigated. They lead to analytical expressions for the amplitude and period of free-running rhythms and for the frequency limits of the entrainment region. The free-running period increases quadratically with stiffness. Both period and amplitude depend on the value of the constant external force. The width of the range of entrainment is mostly determined by the external force, whereas the relative position of this range follows the intrinsic period of the oscillator. Experiments with forced and spontaneous internal desynchronization were evaluated using these analytical expressions, and estimates were obtained for the intrinsic period of the oscillator, its stiffness, and the external force. A knowledge of these model parameters is essential for predictions about circadian dynamics, and there are practical implications for the assessment of the adaptation after rapid transmeridian travel.     

A Mathematical Model of the Human Circadian System and Its Application to Jet Lag

A mathematical model of the circadian system is described that is appropriate for application to jet lag. The core of the model is a van der Pol equation with an external force. Approximate solutions of this equation in which the external force is composed of a constant and an oscillating term are investigated. They lead to analytical expressions for the amplitude and period of free-running rhythms and for the frequency limits of the entrainment region. The free-running period increases quadratically with stiffness. Both period and amplitude depend on the value of the constant external force. The width of the range of entrainment is mostly determined by the external force, whereas the relative position of this range follows the intrinsic period of the oscillator. Experiments with forced and spontaneous internal desynchronization were evaluated using these analytical expressions, and estimates were obtained for the intrinsic period of the oscillator, its stiffness, and the external force. A knowledge of these model parameters is essential for predictions about circadian dynamics, and there are practical implications for the assessment of the adaptation after rapid transmeridian travel.     

RetroPred: A tool for prediction, classification and extraction of non-LTR retrotransposons (LINEs & SINEs) from the genome by integrating PALS, PILER, MEME and ANN

The problem of predicting non-long terminal repeats (LTR) like long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs) from the DNA sequence is still an open problem in bioinformatics. To elevate the quality of annotations of LINES and SINEs an automated tool "RetroPred" was developed. The pipeline allowed rapid and thorough annotation of non-LTR retrotransposons. The non-LTR retrotransposable elements were initially predicted by Pairwise Aligner for Long Sequences (PALS) and Parsimonious Inference of a Library of Elementary Repeats (PILER). Predicted non-LTR elements were automatically classified into LINEs and SINEs using ANN based on the position specific probability matrix (PSPM) generated by Multiple EM for Motif Elicitation (MEME). The ANN model revealed a superior model (accuracy = 78.79 +/- 6.86 %, Q(pred) = 74.734 +/- 17.08 %, sensitivity = 84.48 +/- 6.73 %, specificity = 77.13 +/- 13.39 %) using four-fold cross validation. As proof of principle, we have thoroughly annotated the location of LINEs and SINEs in rice and Arabidopsis genome using the tool and is proved to be very useful with good accuracy. Our tool is accessible at http://www.juit.ac.in/RepeatPred/home.html.     

Environmental and Socioeconomic Interactions in the Evolution of Traditional Irrigated Lands: A Dynamic System Model

The Huerta de Murcia is a traditionally irrigated land located in the middle lowland area of the Segura River around the city of Murcia, Southeast Spain. During the twentieth century several factors, such as the creation of new irrigated lands and the urbanization of traditionally irrigated lands, have changed the use of natural resources, giving rise to a growing imbalance between water resources and irrigation demands and a loss of fertile soil and other environmental and cultural values of this traditionally agricultural area. Such factors constitute environmental problems that will need to be controlled if more sustainable conditions for agriculture are to be achieved. The objectives of the present work are to develop a dynamic system model containing the main social, economic, and environmental and to use this model to explore the long-term effects of several policies designed to promote the sustainability of this agrolandscape. Some preliminary conclusions suggest that regulation and agricultural policy are not enough to stop the loss of traditionally irrigated lands and that additional water management and environmental policies are necessary.     

Application of the Model System of Hormonal Stimulation of the Sturgeon Oocyte Maturation and Ovulation in vitro for Solving Some Fundamental and Applied Problems

The author summarizes the results of many-year application of the model of in vitro sturgeon oocyte maturation for different purposes, such as comparison of gonadotropic activities of different preparations, selection of females for breeding, and studying the effects of different factors in order to improve the breeding technology. Special attention is paid to factors that can affect the results of experiments on hormonal stimulation of in vitro oocyte maturation and ovulation and their interpretation. Two other phenomena are discussed: the inhibitory effect of gonadotropic pituitary hormones on the progesterone-induced in vitro oocyte maturation and the nonhormonal induction of oocyte maturation, further studies of which can elucidate the mechanisms underlying the hormonal regulation of oogenesis in sturgeons.     

Cadmium Dynamics in the Rhizosphere and Cd Uptake of Different Plant Species Evaluated by A Mechanistic Model

Maize, sunflower, flax, and spinach differed in the accumulation of Cd when grown on a Cd contaminated soil. This was mainly due to the different Cd net influx, I_n , that varied among species by a factor of up to 30. The objective of this study was to find possible reasons for the different Cd I_n by using a mechanistic model. After 14 days of Cd uptake the model calculated only a small Cd depletion at the root surface, e.g. from 0.22 μmol L^?1down to 0.19 μmol L^?1for maize and from 0.48 μmol L^?1down to 0.35 μmol L^?1for spinach. Even so the model always overestimated the Cd I_n , for spinach by a factor of 1.5 and for maize by a factor of 10. Only simulating a decrease of C_Li or the root absorbing power, α, by 40% to 90% gave an agreement of calculated and measured I_n . This may be interpreted as that about 40% in the case of spinach and 90% in the case of maize of the Cd in soil solution were not accessible for plant uptake. The high sensitivity to α also shows that not the Cd transport to the root but α was limiting the step for Cd uptake.     

Assessment of Effects of Human Development on the Environment by Using System Dynamic Modeling Technique (SD): A Case Study of the Mkomazi Watershed (Pangani Basin) in Northeastern Tanzania

This study analyzes land use changes due to human development in the Mkomazi Valley, Tanzania, and its impacts on nature using the SD–Modeling (System Dynamic modeling) technique. Ultimately this method relates environment and economy of society with regard to a seasonal rainfall–based agriculture practice and their harmonization with irrigation agriculture for development sustainability. VENSIM PLE (VENTANA SIMULATION ENVIRONMENT, PERSONAL LEARNING EDITION 2002 VENSIM PLE (VENTANA SIMULATION ENVIRONMENT PERSONAL LEARNING EDITION), 2002, Vensim Product Center,Ventana Systems Inc URL:http://www.vensim.com, E-mail: plesupport@vensim.com  [Google Scholar]) software, which simplified the assessment, was used to build a SD–model that accommodated changes in Population, Deforestation, Gross Domestic Product (GDP), and Basin Storage. Model results indicate groundwater behavior, deforestation, public opinion and decreased health of the farmers all relate to changes in land use (i.e., introduction of a rice development project) with its associated environment degradation, deforestation, and poverty due to deforestation. Moreover, these changes might be the cause of animal flight from the Mkomazi game reserve and an increase in human disease and deaths. Finally, it is concluded that uncontrolled human activities and behavior are the main causes of environmental degradation and therefore a brief summary is presented on challenges and opportunities for decision–makers on the sustainable development of the Mkomazi Valley.