Expression of Hemispheric Asymmetry and Psychological Type in the EEG Traveling Wave

Spontaneous EEG patterns were recorded from 16 derivations in the parieto-occipital area over 2 min for subjects in the resting state with the eyes closed. Further, computer analysis of the current pattern of EEG phase relationships between all derivations was conducted, followed by visualization in real time of the trajectory and velocity of the traveling EEG wave as a computerized animation over the contour of the head. On the basis of visual observations and objective statistical analysis, we found consistent individual characteristics of the time course and trajectory of the traveling wave, which were compared to the results of psychological testing of the subjects. Most characteristic were modulations of the electric activity (traveling) in the transverse direction (from left to right and from right to left) and along the diagonal from the left anterior to the right posterior areas. Distinct groups of subjects were found with the predominance of one or the other trajectory type. The specific direction of the diagonal traveling was significantly correlated with the level of extroversion of the subject: extroverts were characterized by traveling of electric waves from the occiput forward to the vertex along the diagonal indicated, whereas for introverts, traveling from the vertex to the occiput was typical.     

Traveling Wave Solutions of a Nerve Conduction Equation

We consider a pair of differential equations whose solutions exhibit the qualitative properties of nerve conduction, yet which are simple enough to be solved exactly and explicitly. The equations are of the FitzHugh-Nagumo type, with a piecewise linear nonlinearity, and they contain two parameters. All the pulse and periodic solutions, and their propagation speeds, are found for these equations, and the stability of the solutions is analyzed. For certain parameter values, there are two different pulse-shaped waves with different propagation speeds. The slower pulse is shown to be unstable and the faster one to be stable, confirming conjectures which have been made before for other nerve conduction equations. Two periodic waves, representing trains of propagated impulses, are also found for each period greater than some minimum which depends on the parameters. The slower train is unstable and the faster one is usually stable, although in some cases both are unstable.     

A Dendritic Mechanism for Decoding Traveling Waves: Principles and Applications to Motor Cortex

Traveling waves of neuronal oscillations have been observed in many cortical regions, including the motor and sensory cortex. Such waves are often modulated in a task-dependent fashion although their precise functional role remains a matter of debate. Here we conjecture that the cortex can utilize the direction and wavelength of traveling waves to encode information. We present a novel neural mechanism by which such information may be decoded by the spatial arrangement of receptors within the dendritic receptor field. In particular, we show how the density distributions of excitatory and inhibitory receptors can combine to act as a spatial filter of wave patterns. The proposed dendritic mechanism ensures that the neuron selectively responds to specific wave patterns, thus constituting a neural basis of pattern decoding. We validate this proposal in the descending motor system, where we model the large receptor fields of the pyramidal tract neurons — the principle outputs of the motor cortex — decoding motor commands encoded in the direction of traveling wave patterns in motor cortex. We use an existing model of field oscillations in motor cortex to investigate how the topology of the pyramidal cell receptor field acts to tune the cells responses to specific oscillatory wave patterns, even when those patterns are highly degraded. The model replicates key findings of the descending motor system during simple motor tasks, including variable interspike intervals and weak corticospinal coherence. By additionally showing how the nature of the wave patterns can be controlled by modulating the topology of local intra-cortical connections, we hence propose a novel integrated neuronal model of encoding and decoding motor commands.     

一类含时滞的Logistic反应扩散方程的波前解

研究一类含时滞的Logistic滞反应扩散方程的波前解．通过构造合适的上下解,证明了当时滞充分小时,方程存在波前解．用线性化方法,给出了存在波前解的时滞τ取值范围的一个估计．     

一类时滞反应扩散方程的稳态解和行波解

本文讨论了一类造血生物模型在Dirichlet边值条件下稳态解的全局吸引性,并利用上、下解技术和单调迭代方法讨论了行波解的存在性.     

一个具有年龄结构的单种群离散反应扩散模型的波前解

利用上下解方法研究了一个具有年龄结构的单种群离散反应扩散模型波前解的存在性,并证明了存在具有临界波速的波前解.     

Informing Packaging Design Decisions at Toyota Motor Sales Using Life Cycle Assessment and Costing

Throughout their life cycle stages—material production, package manufacture, distribution, end-of-life management—packaging systems consume natural resources and energy, generate waste, and emit pollutants. Each of these stages also carries a financial cost. Motivated by a desire to decrease environmental burdens while reducing financial costs associated with the packaging of accessory and service parts, Toyota Motor Sales (TMS) partnered with the Donald Bren School of Environmental Science & Management to build a life cycle assessment and costing tool to support packaging design decisions. The resulting Environmental Packaging Impact Calculator (EPIC) provides comprehensive life cycle assessment (LCA) and life cycle costing (LCC). It allows packaging designers to identify environmentally and economically preferable packaging systems in daily decision-making. EPIC's parameterized process flow model allows users to assess many different packaging systems using a single model. Its input/output interface is designed for users without preexisting knowledge of LCA theory or practice and calculates results based on relatively few input data. The main motivation behind this environmental design tool is to provide relevant information to those individuals who are in the best position to reduce life cycle impacts and costs from TMS's packaging and distribution systems.     

A Real-Time Brain-Machine Interface Combining Motor Target and Trajectory Intent Using an Optimal Feedback Control Design

Real-time brain-machine interfaces (BMI) have focused on either estimating the continuous movement trajectory or target intent. However, natural movement often incorporates both. Additionally, BMIs can be modeled as a feedback control system in which the subject modulates the neural activity to move the prosthetic device towards a desired target while receiving real-time sensory feedback of the state of the movement. We develop a novel real-time BMI using an optimal feedback control design that jointly estimates the movement target and trajectory of monkeys in two stages. First, the target is decoded from neural spiking activity before movement initiation. Second, the trajectory is decoded by combining the decoded target with the peri-movement spiking activity using an optimal feedback control design. This design exploits a recursive Bayesian decoder that uses an optimal feedback control model of the sensorimotor system to take into account the intended target location and the sensory feedback in its trajectory estimation from spiking activity. The real-time BMI processes the spiking activity directly using point process modeling. We implement the BMI in experiments consisting of an instructed-delay center-out task in which monkeys are presented with a target location on the screen during a delay period and then have to move a cursor to it without touching the incorrect targets. We show that the two-stage BMI performs more accurately than either stage alone. Correct target prediction can compensate for inaccurate trajectory estimation and vice versa. The optimal feedback control design also results in trajectories that are smoother and have lower estimation error. The two-stage decoder also performs better than linear regression approaches in offline cross-validation analyses. Our results demonstrate the advantage of a BMI design that jointly estimates the target and trajectory of movement and more closely mimics the sensorimotor control system.     

一类S-I传染病模型行波解的存在性

本文研究了一类具有扩散且是非线性传染率的SI传染病模型,分析了模型的行波解的存在性条件,给出了最小波速与产生单调和振荡行波解的条件,并且进行了计算机仿真．     

Substrate Binding Mechanism of a Type I Extradiol Dioxygenase

A meta-cleavage pathway for the aerobic degradation of aromatic hydrocarbons is catalyzed by extradiol dioxygenases via a two-step mechanism: catechol substrate binding and dioxygen incorporation. The binding of substrate triggers the release of water, thereby opening a coordination site for molecular oxygen. The crystal structures of AkbC, a type I extradiol dioxygenase, and the enzyme substrate (3-methylcatechol) complex revealed the substrate binding process of extradiol dioxygenase. AkbC is composed of an N-domain and an active C-domain, which contains iron coordinated by a 2-His-1-carboxylate facial triad motif. The C-domain includes a β-hairpin structure and a C-terminal tail. In substrate-bound AkbC, 3-methylcatechol interacts with the iron via a single hydroxyl group, which represents an intermediate stage in the substrate binding process. Structure-based mutagenesis revealed that the C-terminal tail and β-hairpin form part of the substrate binding pocket that is responsible for substrate specificity by blocking substrate entry. Once a substrate enters the active site, these structural elements also play a role in the correct positioning of the substrate. Based on the results presented here, a putative substrate binding mechanism is proposed.     

Activity Characteristics and Tyrosinase Inhibition Mechanism of a Silk Fibroin Oligopeptide and Cordyceps Polysaccharide Composite

International Journal of Peptide Research and Therapeutics - Silk fibroin is an excellent raw material for medical products as it shows remarkable biocompatibility, water-based processing, and...     

Stapled BH3 Peptides against MCL-1: Mechanism and Design Using Atomistic Simulations

Atomistic simulations of a set of stapled alpha helical peptides derived from the BH3 helix of MCL-1 (Stewart et al. (2010) Nat Chem Biol 6: 595-601) complexed to a fragment (residues 172-320) of MCL-1 revealed that the highest affinity is achieved when the staples engage the surface of MCL-1 as has also been demonstrated for p53-MDM2 (Joseph et al. (2010) Cell Cycle 9: 4560-4568; Baek et al. (2012) J Am Chem Soc 134: 103-106). Affinity is also modulated by the ability of the staples to pre-organize the peptides as helices. Molecular dynamics simulations of these stapled BH3 peptides were carried out followed by determination of the energies of interactions using MM/GBSA methods. These show that the location of the staple is a key determinant of a good binding stapled peptide from a bad binder. The good binder derives binding affinity from interactions between the hydrophobic staple and a hydrophobic patch on MCL-1. The position of the staple was varied, guiding the design of new stapled peptides with higher affinities.     

Discharge in a Subthreshold Microwave Beam as an Unusual Type of Ionization Wave

Plasma Physics Reports - Ionization−overheating instability of a non-self-sustained discharge in air in a subthreshold microwave field creates a self-sustained discharge with a fine cellular...     

Binding Mechanism and Electrochemical Properties of M13 Phage-Sulfur Composite

Self-assembly of nanostructured materials has been proven a powerful technique in material design and synthesis. By phage display screening, M13 phage was found to strongly bind sulfur particles. Fourier transform infrared and X-ray photoelectron spectroscopy measurements indicated that the strong sulfur-binding ability of M13 phage derives from newly generated S-O and C-S bonds. Using this phage assembled sulfur composite in a lithium battery, the first discharge capacity reached 1117 mAh g^-1, which is more than twice that of the sulfur only cathode. Besides, the negative polysulfide shuttle effect in a lithium-sulfur battery was significantly suppressed.     

Clinical Results of Real-Time Ultrasonic Scanning of the Heart Using a Phased Array System

This report describes the operating characteristics and initial clinical results of a new echocardiographic system that produces real-time, high resolution, cross-sectional images of the heart. This system relies upon phased-array principles to rapidly steer and focus the ultrasound beam through the cardiac structures under investigation. A hand-held, linear array of 24 transducers is manipulated on the patient''s chest to direct the interrogating plane at various cardiac structures. Images of high line density are presented in selectable sector arcs to a maximum of 90 degrees. This imaging system has been used clinically in over 2,000 patients in the past two and one-half years. Its use in the detection of altered states of ventricular and valvular pathology has been described.     

Design and Experiment of a Deformable Bird-inspired UAV Perching Mechanism

Energy consumption and acoustic noise can be significantly reduced through perching in the sustained flights of small Unmanned Aerial Vehicles(UAVs).However,the existing flying perching robots lack good adaptability or loading capac-ity in unstructured environments.Aiming at solving these problems,a deformable UAV perching mechanism with strong adaptability and high loading capacity,which is inspired by the structure and movements of birds'feet,is presented in this paper.Three elastic toes,an inverted crank slider mechanism used to realize the opening and closing movements,and a gear mechanism used to deform between two configurations are included in this mechanism.With experiments on its performance towards different objects,Results show that it can perch on various objects reliably,and its payload is more than 15 times its weight.By integrating it with a quadcopter,it can perch on different types of targets in outdoor environments,such as tree branches,cables,eaves,and spherical lamps.In addition,the energy consumption of the UAV perching system when perching on objects can be reduced to 0.015 times that of hovering.     

前列腺钙化灶的超声显像诊断与分型的临床研究

目的：探究超声显像诊断前列腺钙化灶（PFC）的临床实用价值和超声分型。方法：对1284倒经腹部超声显像诊断为PFC的临床资料进行回顾性分析,并根据超声所见进行分型。结果：超声显像诊断PFC1,284例,单发768倒（59．81％）。多发516例（40．19％）;钙化灶直径2-36mm;Ⅰ度542例（42．21％）,Ⅱ度460例（35．83％）,Ⅲ度282例（21．96％）;孤立型412例（32．09％）,散在型319例（24．84％）,聚集型395例（30．76％）,条索型158例（12-31％）。内腺435例（33．88％）、外腺348例（（27．10％）、内外腺交界处351例（27．34％）、后尿道周围150例（11．68％）。单纯性钙化520例（40．50％）,合并前列腺增生597例（46．50％）、前列腺炎129例（10．05％）、前列腺囊肿36例（2．80％）、前列腺癌2例（0．16％）。结论：PFC是男性泌尿生殖系统常见疾病,其程度和类型与年龄密切相关,近半数与前列腺增生并存,可能与组织退变、增生、炎症、钙磷代谢紊乱等因素有关。超声显像是诊断PFC最可靠、最简便的方法,具有重要的l陆床实用价值。     

Complex Mechanism of Enhanced Optical Transmission Through a Composite Coaxial/Circular Aperture

Making use of the FDTD simulation, we study light transmission properties of a composite coaxial/circular aperture milled in a thin metallic film. Representing the aperture as consisting of segments of coaxial and hollow waveguides, connected in series, we show that there are three characteristic frequencies (the cutoff frequencies of the coaxial and hollow waveguides and the frequency of a longitudinal standing wave in the coaxial waveguide segment) and four regimes of operation (bounded by these frequencies, as well as by low- and high-frequency limits) which determine the behavior of the transmission efficiency. For two regimes of operation (for frequencies between the cutoff frequency of the coaxial waveguide and the resonant frequency of the longitudinal standing wave), both segments can contribute to the overall transmission. For other two regimes, either no enhancement occurs or only one segment contributes to the transmission efficiency. A way is proposed to optimize the transmission through the composite aperture. In particular, as we show, the transmission efficiency of the aperture can be enhanced by decreasing the exit hole size (radius of the circular aperture). In the considered case, an increase of the transmission efficiency exceeds 50%. The effect of the enhanced transmission is shown to result from both vertical and in-plane surface plasmon resonances occurring in the aperture.     

Diffusing Wave and Ultrasonic Spectroscopy of Rennet-Induced Gelation of Milk in the Presence of High-Methoxyl Pectin

Rennet-induced aggregation was studied in milk systems containing high-methoxyl pectin (HMP) using ultrasonic and diffusing wave spectroscopy. These two techniques allow for in situ measurements of sol–gel transitions without the need for dilution. At low HMP concentrations, the casein micelles aggregation behavior was similar to that of skim milk, although changes could be noted in the microstructure of the renneted gels. At HMP concentrations between 0.1 and 0.15%, phase-separation kinetics were slower than the rennet-induced aggregation, and different microstructures formed caused by different dynamics of interactions between casein micelles present in HMP-depleted flocs. Higher amounts of HMP failed to create a continuous gel, as phase separation occurred at a faster rate than rennet aggregation. These results highlight the importance of non-invasive techniques in the study of concentration-dependent phase separating and aggregating systems, as only with observations in situ is it possible to determine new ways to control the structuring of protein–polysaccharide mixed systems.