Distributed moment histogram: a neurophysiology based method of agonist and antagonist trunk muscle activity prediction

A neurocortical-based technique of muscle recruitment is presented to solve the muscle indeterminacy problem for lumbar torso modeling. Cortical recordings from behaving primates have established motor cortex cells that respond to a wide range of task directions, but are tuned to a preferred direction. A characteristic activity pattern of these neurons seems to be associated with effort direction. It was hypothesized that a model which recruits muscles based on a similar distribution would predict antagonistic muscle activity with greater realism than a widely referenced optimization formulation. The predictions of the Distributed Moment Histogram (DMH) method were evaluated under common speed (< 30 degrees s-1) sagittal plane lifting conditions using five subjects. The predicted forces showed high correspondence with agonist and antagonist myoelectric patterns. The mean coefficient of determination for the erector spinae was r2 = 0.91, and 0.41 for the latissimus. For the antagonistic muscles, the rectus abdominus was found to be electrically silent (< 3% MVC) and no activity was predicted by the method. The external oblique muscle was observed to be minimally active (< 16% MVC), and the DMH method predicted its mostly constant activity with a mean standard error of 1.6% MVC. The realistic antagonistic predictions supported the hypothesis and justify this cortical based technique as an alternative for muscle tension estimation in biomechanical torso modeling. A primary advantage of this method is its computational simplicity and direct physiologic analog.     

Friedreich's ataxia with retained tendon reflexes: molecular genetics, clinical neurophysiology, and magnetic resonance imaging

Lower limb areflexia is generally regarded as an essential criterion for the diagnosis of Friedreich's ataxia (FRDA). We describe a family with a recessive form of early-onset ataxia in which one member had a phenotype typical of FRDA whereas another, with retained tendon reflexes in the lower limbs, did not have electrophysiologic evidence of the usual severe afferent axonal neuropathy of FRDA. In contrast, somatosensory evoked potentials, eye-movement recordings, and MRI of the head and cervical cord provided results highly suggestive of FRDA in both patients. We performed genetic linkage analysis in this family, using markers tightly linked to the FRDA locus on chromosome 9. Inheritance of identical paternal and maternal genotypes by the affected members, but not by their unaffected siblings, provided supporting evidence that this disorder may result from mutation within the FRDA gene or is tightly linked to the investigated loci on chromosome 9.     

Charcot-Marie-Tooth disease--muscle biopsy findings in relation to neurophysiology

Nine patients with Charcot-Marie-Tooth disease with reduced motor nerve conduction velocity (MNCV), i.e. type 1 (CMT1), demyelinating form, and nine patients with Charcot-Marie-Tooth disease with normal or near-normal MNCV, i.e. type 2 (CMT2), axonal form, were subjected to percutaneous muscle biopsy from the anterior tibial muscle in order to characterize histopathological abnormalities and evaluate differences between the two groups. Data from the biopsies were compared with those from 18 age- and sex-matched healthy controls. Muscle biopsies from the CMT1 patients exhibited angular atrophic fibres that were scattered or in small groups, findings commonly described as neuropathic. Muscle biopsies from the CMT2 patients exhibited atrophic fibres that were rounded or elongated in groups and hypertrophic fibres with central nuclei and fibre splitting. There were also increased amounts of connective tissue, 'whorled fibres', degeneration and signs of regeneration, findings commonly regarded as myopathic. In conclusion, muscle biopsies from patients with CMT1 and CMT2 showed markedly different histopathological abnormalities. Possible underlying mechanisms are discussed.     

Studies on the neurophysiology of the vas deferens

In order to investigate the mechanism of sperm transport along the genital ducts, intraluminal pressure of isolated segments of the vas deferens was recorded in vivo. Responses to filling and mechanical as well as pharmacologic and electric stimulation of the autonomic nervous system were monitored. Contraction waves were initated in response to the stretch of filling and from mechanical stimulation. Pharmacologic response was variable. Low doses of alpha-adrenergic stimulant produced an increase in frequency of the contraction wave. Large doses of the same drug induced stroking contraction of the entire vas. alpha-Blocking drugs did not alter the rhythmic activity of the vas. beta-Adrenergic stimulation blocked peristaltic activity while administration of parasympathomimetic drugs increased the force of contraction. Electric stimulation of the hypogastric nerve produced strong sustained contractions. These data suggest that, whenever stretched, the vas deferens responds by regular peristaltic waves of low amplitude. These peristaltic waves can be enhanced by sympathomimetics or electric stimulation of the sympathetic system. The contents of the vas are propulsed into the urethra through strong rhythmic contractions of the entire vas.     

Computer assisted neurophysiology by a distributed Java program

The mere appearance of a tubular, epithelially-covered, bilateral structure, no matter how minuscule, on the anteroventral nasal septum of tetrapods, is generally called the vomeronasal organ (of Jacobson). However, considering the functionality of this chemosensory structure, the presence of a non-cilated (microvillar) neuroepithelium (and not just any odd type of epithelium) encased in a variously shaped vomeronasal cartilage, along with vomeronasal nerve bundles and above all an accessory olfactory bulb connected to the limbic vomeronasal amygdala, are the absolute essential neurostructural characteristics and anatomic requirement for a functional VNO and the accessory olfactory system in any tetrapod. The distribution of the vomeronasal organ is reported here in two mammalian orders: Chiroptera and Primates. An impressive data pool on the vomeronasal organ of bats is now available, pointing to the fact that at this time bats may be the only group in which this organ system is extremely variable, ranging from total absence (even in the embryo) to spectacular development with numerous intervening stages in different chiropteran species. Of the eighteen bat families, only one family of New World leaf-nosed bats, family Phyllostomidae, exhibits functional vomeronasal organs. The vespertilionid bat Miniopterus, and the mormoopid bat Pteronotus, present exceptions to this rule. Among Primates, very few species have been rigorously studied. As a result, developmental variability of the vomeronasal organ is almost unknown; either the vomeronasal organ is well developed (such as in New World monkeys) or absent (as in Old World monkeys and great apes) in the adult. The concept whether adult humans or embryonic and fetal forms are endowed with this so-called sixth sense, is a controversial one and is under intense study in our laboratory and by others. The general phylogenetic implications based on our cladistic analysis of bats are that the vomeronasal organ complex has evolved several times. Among the prosimians and platyrrhine primates, the organ is well developed, although to a varying degree. Among catarrhine primates, its loss has occurred only once, as it is generally absent in the adult forms.     

Using knockout and transgenic mice to study neurophysiology and behavior

Reverse genetics, in which detailed knowledge of a gene of interest permits in vivo modification of its expression or function, provides a powerful method for examining the physiological relevance of any protein. Transgenic and knockout mouse models are particularly useful for studies of complex neurobiological problems. The primary aims of this review are to familiarize the nonspecialist with the techniques and limitations of mouse mutagenesis, to describe new technologies that may overcome these limitations, and to illustrate, using representative examples from the literature, some of the ways in which genetically altered mice have been used to analyze central nervous system function. The goal is to provide the information necessary to evaluate critically studies in which mutant mice have been used to study neurobiological problems.     

The rat as an experimental model for sleep neurophysiology.

The aim of this study was to develop a sleep-wake recording system for rats that would yield results more comparable to those obtained from cats than those that are usually reported. For 18 male Sprague-Dawley rats, the authors combined measures of cortical and hippocampal electroencephalogram (EEG) and neck muscle electromyogram with the electrooculogram and pontine EEG, so that the behavioral states could be identified with greater confidence with the use of polygraphic criteria developed in the cat and so that the distinctive phasic events of REM sleep could be more easily studied in the rat. The results suggest that for many neurophysiological studies, the rat is a suitable alternative to the cat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why Freud failed: Some implications for neurophysiology and sociobiology.

Many parallels have recently been drawn between Freud's early work and the goals of the contemporary neurophysiology of mind and sociobiology. In this article it is argued that the portrayal of Freud as a reductionist and a biological determinist is incorrect. As a consequence, so is the perceived alignment of Freud with neurophysiology and sociobiology. But it is also true that, in his early work, Freud faced many of the same problems and issues that confront those interested in theories of mind and of human nature, and an understanding of how Freud faced these issues may inform our increasing interest in views of mind and behavior emanating from the life sciences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forty-two years of neurophysiology in Aragon in relation to other neurological specialties

INTRODUCTION: Forty two years after the first EEG had been done in our community we decided (encouraged by the Sociedad Aragonesa de Neurofisiología Clínica) to write a biographical synopsis of the specialty of neurophysiology in Aragón, since knowledge of the past usually makes for a better future. DEVELOPMENT: Initially, seven specialists, many others with their smaller contributions, the proceedings of the Sociedad Aragonesa de Neurofisiología Clínica, the proceedings of Serrate and the archives of the chair of Psychiatry of Zaragoza University have all provided information about the history of neurophysiology in Aragón. We studied the activities of public hospitals, private centres as well as academic neurophysiology activities. We also evaluated influences from outside our community in training different specialists, finding information about training in France and Germany an, in our country, in Barcelona and Pamplona. CONCLUSIONS: We observed that the specialty has now become fully developed in our community. However, it had done so in close relationship with the specialties of Neurology and Psychiatry, with which it is perfectly integrated. The university has been successfully involved in development of the specialty and, in recent years, so has the Sociedad Aragonesa de Neurofisiología Clínica.     

分布式信息系统的分布式查询优化算法

随着网络技术的发展，信息系统在结构上呈现分布式。介绍了分布式信息系统中分布式查询的原子查询、不确定查询、合并查询、连接查询、复合查询等算法，重点研究了分布式查询的核心算法连接查询的优化问题。     

分散处理CIMS

介绍了分散ＣＩＭＳ的概念、结构和目前发展情况。     

Microgrids and Distributed Generation

Application of individual distributed generators can cause as many problems as it may solve. A better way to realize the emerging potential of distributed generation is to take a system approach which views generation and associated loads as a subsystem or a “microgrid.” The sources can operate in parallel to the grid or can operate in island, providing utility power station services. The system will disconnect from the utility during large events (e.g., faults and voltage collapses), but may also intentionally disconnect when the quality of power from the grid falls below certain standards. Utilization of waste heat from the sources will increase total efficiency, making the project more financially attractive. University of Wisconsin laboratory verification of microgrid control concepts are included.