Electrocardiogram (ECG) patterns of left anterior fascicular block and conduction impairment in ventricular myocardium: a whole-heart model-based simulation study

Left anterior fascicular block (LAFB) is a heart disease identifiable from an abnormal electrocardiogram (ECG). It has been reported that LAFB is associated with an increased risk of heart failure. Non-specific intraventricular conduction delay due to the lesions of the conduction bundles and slow cell to cell conduction has also been considered as another cause of heart failure. Since the location and mechanism of conduction delay have notable variability between individual patients, we hypothesized that the impaired conduction in the ventricular myocardium may lead to abnormal ECGs similar to LAFB ECG patterns. To test this hypothesis, based on a computer model with a three dimensional whole-heart anatomical structure, we simulated the cardiac exciting sequence map and 12-lead ECG caused by the block in the left anterior fascicle and by the slowed conduction velocity in the ventricular myocardium. The simulation results showed that the typical LAFB ECG patterns can also be observed from cases with slowed conduction velocity in the ventricular myocardium. The main differences were the duration of QRS and wave amplitude. In conclusion, our simulations provide a promising starting point to further investigate the underlying mechanism of heart failure with LAFB, which would provide a potential reference for LAFB diagnosis. the angulation of impaction having little effect on facture risk.     

各向异性媒质中电偶极子辐射功率的角分布

分析振荡电偶极子在各向异性磁媒质中沿极轴振荡时其辐射能流密度的角分布和辐射功率的角分布情况,并与各向同性媒质中振荡电偶极子沿极轴振荡时辐射能流密度的角分布和辐射功率的角分布情况进行对比,得出更有效地利用电各向同性磁各向异性媒质的理论依据.yh     

振荡电偶极子在各向异性媒质中的总辐射功率

对各向异性媒质中电磁场辐射问题的研究．已完成了电偶极子的辐射电磁场及能流密度表达式的推导，章进而在各向异性球坐标系中通过球面积分先求得在各向异性媒质中电偶极辐射的总功率，再通过坐标变换回到各向同性坐标系中．得到用通常直角坐标系表述的电偶极在各向异性媒质中辐射总功率的表达式．当媒质为各向同性时其结果与预期的结果相吻合，验证了推导结果的正确性．利用该结果可对电偶极在各向异性媒质中的辐射效果做出判断，而且为测定各向异性媒质中电偶极辐射的总辐射功率提供了理论依据，从而谋求开发与应用．     

A simple dissection method for the conduction system of the human heart

A simple dissection guide for the conduction system of the human heart is shown. The atrioventricular (AV) node, AV bundle, and right bundle branch were identified in a formaldehyde‐fixed human heart. The sinu‐atrial (SA) node could not be found, but the region in which SA node was contained was identified using the SA nodal artery. Gross anatomical observation of the conduction system is useful for understanding the structure and function of the heart. Anat Sci Ed 2:78–80, 2009. © 2009 American Association of Anatomists.     

双相各向同性介质中弹性波方程的有限差分解法及波场模拟

基于双相各向同性介质模型,推导了双相各向同性介质中波动方程的有限差分格式,并对其进行了数值模拟.结果表明,弹性波在双相各向同性介质中传播时除了存在常规的快纵波(qP1)和横波以外,还存在慢纵波(qP2),并且慢纵波的速度明显小于快纵波.     

Non-Rigid Object Tracking by Anisotropic Kernel Mean Shift

Mean shift,an iterative procedure that shifts each data point to the average of data points in its neighborhood,has been applied to object tracker.However,the traditional mean shift tracker by isotropic kernel often loses the object with the changing object structure in video sequences,especially when the object structure varies fast.This paper proposes a non-rigid object tracker by anisotropic kernel mean shift in which the shape,scale,and orientation of the kernels adapt to the changing object structure.The experimental results show that the new tracker is self-adaptive and approximately twice faster than the traditional tracker,which ensures the robustness and real time of tracking.     

Computational Simulation of Hypervelocity Penetration Using Adaptive SPH Method

The normal hypervelocity impact of an Al-thin plate by an Al-sphere was numerically simulated by using the adaptive smoothed particle hydrodynamics (ASPH) method. In this method, the isotropic smoothing algorithm of standard SPH is replaced with anisotropic smoothing involving ellipsoidal kernels whose axes evolve automatically to follow the mean particle spacing as it varies in time, space, and direction around each particle. Using the ASPH, the anisotropic volume changes under strong shock condition are captured more accurately and clearly. The sophisticated features of meshless and Lagrangian nature inherent in the SPH method are kept for treating large deformations, large inhomogeneities and tracing free surfaces in the extremely transient impact process. A two-dimensional ASPH program is coded with C . The developed hydrocode is examined for example problems of hypervelocity impacts of solid materials. The results obtained from the numerical simulation are compared with available experimental ones. Good agreement is observed.     

General solutions for special orthotropic piezoelectric media

INTRODUCTION General solution is a convenient, effective method for solving space problems such as problems of infinite, semi-infinite and two-phase infinite media. For linear theory of piezoelasticity, Ding et al.(1996; 1997a) gave the general solution for coupled equa-tions for transversely piezoelectric media using po-tential theory. Ding et al.(1997b; 1997c) gave the general solution of plane problem. Based on the gen-eral solution, Ding et al.(1997a) presented the closed form fundam…     

Democratizing computer science knowledge: transforming the face of computer science through public high school education

Despite the fact that computer science (CS) is the driver of technological innovations across all disciplines and aspects of our lives, including participatory media, high school CS too commonly fails to incorporate the perspectives and concerns of low-income students of color. This article describes a partnership program – Exploring Computer Science (ECS) – that directly counters this problem in our nation's second largest school district. With a mission of democratizing CS learning, we argue that despite the constraints of working within public schools, it is imperative to do so. We discuss the ECS program based on inquiry, culturally relevant curriculum, and equity-oriented pedagogy. We describe two ECS-affiliated projects that highlight the importance of authorship, purpose, and agency for student learning and engagement: DietSens using mobile technology to study community health, and a project in which students create video games about social issues. Our work offers a counter-narrative to those who have written off the possibilities of working within public schools and a debunking of the too widespread myth within our educational system that females and students of color are inherently uninterested in rigorous CS learning.     

Solving Pavlov's puzzle: Attentional, associative, and flexible configural mechanisms in classical conditioning

This article introduces a new "real-time" model of classical conditioning that combines attentional, associative, and "flexible" configural mechanisms. In the model, attention to both conditioned (CS) and configural (CN) stimuli are modulated by the novelty detected in the environment. Novelty increases with the unpredicted presence or absence of any CS, unconditioned stimulus (US), or context. Attention regulates the magnitude of the associations CSs and CNs form with other CSs and the US. We incorporate a flexible configural mechanism in which attention to the CN stimuli increases only after the model has unsuccessfully attempted learn input-output combinations with CS-US associations. That is, CSs become associated with the US and other CSs on fewer trials than they do CNs. Because the CSs activate the CNs through unmodifiable connections, a CS can become directly and indirectly (through the CN) associated with the US or other CSs. In order to simulate timing processes, we simply assume that a CS is formed by a temporal spectrum of short-duration CSs that are activated by the nominal CS trace. The model accurately describes 94?% of the basic properties of classical conditioning, using fixed model parameters and simulation values in all simulations.     

Genetic algorithm for scheduling reentrant jobs on parallel machines with a remote server

This paper considers a reentrant scheduling problem on parallel primary machines with a remote server machine, which is required to carry out the setup operation. In this problem, each job has three operations. The first and last operations are performed by the same primary machine, implying the reentrance, and the second operation is processed on the single server machine. The order of jobs is predetermined in our context. The challenge is to assign jobs to the primary machines to minimize the makespan. We develop a genetic algorithm（GA） to solve this problem. Based on a simple strategy of assigning jobs in batches on the parallel primary machines, the standardized random key vector representation is employed to split the jobs into batches. Comparisons among the proposed algorithm, the branch and bound（BB） algorithm and the heuristic algorithm, coordinated scheduling（CS）, which is only one heuristic algorithm to solve this problem in the literature, are made on the benchmark data. The computational experiments show that the proposed genetic algorithm outperforms the heuristic CS and the maximum relative improvement rate in the makespan is 1.66%.     

Comparison of auditory and visual conditioning stimuli in delay eyeblink conditioning in healthy young adults

Classical eyeblink conditioning (EBC) has been widely used to probe cerebellar function in humans and nonhuman mammals. Although the neural pathways governing behavior in this task are well understood and fairly discrete, it remains unclear in the human literature how conditioned stimuli (CSs) of different modalities (e.g., visual and auditory) influence the exhibition of conditioned responses (CRs). In the present study, therefore, CRs to a visual CS and an auditory CS were examined with the single-cue delay EBC procedure. An initial experiment (N=61) was conducted to identify visual and auditory stimuli that had equal perceived intensities. Using these perceptually equivalent stimuli, a second group of 25 subjects completed auditory and visual EBC procedures in two testing sessions 5–8 days apart. Whereas the acquisition of CRs was similar between the CS modality conditions, the timing of the CRs differed such that earlier CR onset and peak latencies were associated with the visual CS. In addition, CR timing improved across testing sessions, as indicated by the later CR peak latencies exhibited during the second testing session, as compared with the first.     

语码转换的社会属性及其语用功能

语码转换是一种有趣而又独特的社会语言现象。目前,有关语码转换的研究主要集中在两个方面：1.对语码转换概念的探索以及对这一语言现象的历时性研究;2.大量的关于语码转换的语用及句法结构特征的个案研究。本文探讨了语码转换的社会属性及其语用功能。同时,鉴于以往研究中人们对语码转换这一概念缺乏统一的认识,本文也试图为语码转换提出一个工作定义。     

EDGE PARAMETER COMPUTING METHODS FOR ANISOTROPIC VOLUME DATA

ＥＤＧＥＰＡＲＡＭＥＴＥＲＣＯＭＰＵＴＩＮＧＭＥＴＨＯＤＳＦＯＲＡＮＩＳＯＴＲＯＰＩＣＶＯＬＵＭＥＤＡＴＡＸｉｅＸｉａｏｈｕａ（谢筱华）ＬｕｏＬｉｍｉｎ（罗立民）（ＤｅｐａｒｔｉｎｅｎｔｏｆＢｉｏｌｏｇｙａｎｄＭｅｄｉｃａｌＥｎｇｉｎｅｅｒｉｎｇ）Ｅ...     

Reversal from blocking in humans as a result of posttraining extinction of the blocking stimulus

In a blocking procedure, conditioned stimulus (CS) A is paired with the unconditioned stimulus (US) in Phase 1, and a compound of CSs A and X is then paired with the US in Phase 2. The usual result of such a treatment is that X elicits less conditioned responding than if the A-US pairings of Phase 1 had not occurred. Obtaining blocking with human participants has proven difficult, especially if a behavioral task is used or if the control group experiences reinforcement of a CS different from the blocking CS in Phase 1. In the present series, in which human participants and a behavioral measure of learning were used, we provide evidence of blocking, using the above described control condition. Most important, we demonstrate that extinction of the blocking CS (A) following blocking treatment reverses the blocking deficit (i.e., increases responding to X). These results are at odds with traditional associative theories of learning, but they support current associative theories that predict that posttraining manipulations of the competing stimulus can result in a reversal of stimulus competition phenomena.     

Overshadowing and CS duration: counteraction and a reexamination of the role of within-compound associations in cue competition

In the present experiments, we examined the role of within-compound associations in the interaction of the overshadowing procedure with conditioned stimulus (CS) duration, using a conditioned suppression procedure with rats. In Experiment 1, we found that, with elemental reinforced training, conditioned suppression to the target stimulus decreased as CS duration increased (i.e., the CS duration effect), whereas, with compound reinforced training (i.e., the overshadowing procedure), conditioned suppression to the target stimulus increased as CS duration increased. In subsequent experiments, we replicated these findings with sensory preconditioning and demonstrated that extinction of the overshadowing stimulus results in retrospective revaluation with short CSs and in mediated extinction with long CSs. These results highlight the role of the duration of the stimulus in behavioral control. Moreover, these results illuminate one cause (the CS duration) of whether retrospective revaluation or mediated extinction will be observed.     

平面体波在各向异性媒质中的传播

Combining the linear transformation and the solution technique for the cubic equation,a general closed-form analyti solution for bulk waves in orthotropic anisotropic materials is obtained.This method is straightforward and general.Degenerated cases include transversely isotropic,cubic,and isotropic materials.Numerical computations are carried out on a fiber-reinforced composite plate modeled as a transversely isotropic media.The fibers are parallel to the top and bottom surfaces of the plate ,and they are rotated counterclockwise around the plate normal through different angles.The two-dimensional slowness curves corresponding to different rotations are presented graphically.The wave propagation characteristics displayed in slowness surfaces for different fiber orientation are analyzed.     

矩阵酉相抵的充分必要条件

本文证明了下列结论:1.m×n矩阵A与B酉相抵的充分必要条件是tr((AA)~(*K))=tr((B B~*)~K), K=1,2,…,”,m2.m阶方阵A与B有相同奇异值的充分必要条件是tr((AA~*)~K)=tr((B B~*)~K),K=1,2,…,m。     

基于Crystal Space的自定义插件的设计与实现

Crystal Space（简称CS）是一个开源的3D游戏引擎,作为其框架核心的SCF为用户设计和开发基于CS的自定义插件提供了便利。本文介绍了CS和SCF;然后,探讨了SCF在自定义插件等方面所具备的优势,最后,设计及实现了一个基于CS的自定义插件,并详细论述了其中所涉及的关键技术,从中发现,在实际开发过程中,设计及使用符合自己需要的自定义插件,将使基于CS的游戏开发或软件开发更加便利、快捷。     

不纯正不作为犯的等置性分析

不纯正不作为犯的核心问题是不作为与作为的等置性,即对存在结构上不同的两种行为样态适用同一个构成要件进行评价。正是基于等置性,才承认特定的不作为可以成立通常以作为形式实施的犯罪。所以,只有解决了将二者等置评价这一基础问题,才给不纯正不作为犯的成立和对不作为者的定罪科刑提供正当性。等置性如何贯彻在不纯正不作为犯中,即等置性在不纯正不作为犯中的体系地位如何?梳理若干重要的关于等置性体系地位的观点,并对这些观点进行评价。在此基础上,具体地分析成立不纯正不作为犯所要求的等置性的内容。