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PubMed1998

A compact mirror manipulator in the SRRC beamline.

A compact mirror manipulator which has high stiffness and is easily adjustable has been developed for new beamlines at SRRC. It consists of a vertical stem to support the mirror and allows for six-axis precise positioning. The rotation adjustment is designed with a minimum of cross-coupling between adjustments. An independent support is fixed to the ground to reduce vibration from the chamber and the pump. Some performance test results in vacuum and in atmosphere, including vibration, repeatability, long-term drift etc., are described in this paper.

Journal Article↗
PubMed1998

Thermal and deformation analyses of side-cooled monochromator mirrors for the SPring-8/Figure-8 soft X-ray undulator.

The numerical results for a bent parabolic mirror monochromator designed for the SPring-8/Figure-8 soft X-ray undulator are described. A thermal and structural finite-element analysis is presented for side-cooled premirrors of the bent parabolic mirror monochromator. Using a ray-tracing code, the effect of the final induced figure errors on the performance of the premirror are discussed.

Journal Article↗
PubMed1998

Design and performance of a multilayered mirror monochromator in the low-energy region of the VUV.

For the energy region from tens to hundreds of electron volts, the multilayered mirror (MLM) monochromator has never been realized due to the difficulty of reducing the background noise of the total reflection component, in spite of its usefulness in synchrotron radiation experiments. In this work, a double-crystal-type MLM monochromator equipped with a thin-film filter has been designed on the basis of trial fabrication of the mirror-driving system and of Mo/Si and Mo/C MLMs; its performance has been evaluated by calculating its output photon flux. It is shown that by using the MLMs at low incident angles, combined with an appropriate thin-film filter, it is possible to make a practical monochromator with high output photon flux and low background noise.

Journal Article↗
PubMed2006

Single-view-point omnidirectional catadioptric cone mirror imager.

We present here a comprehensive imaging theory about cone mirrors in a single-view-point (SVP) configuration and show that an SVP cone mirror catadioptric system is not only practical but also has unique advantages for certain applications. We show its merits and weaknesses and how to build a workable system.

Computer Simulation↗
PubMed2007

Design analysis of a high-resolution panoramic camera using conventional imagers and a mirror pyramid.

Wide field of view (FOV) and high-resolution image acquisition is highly desirable in many vision-based applications. Several systems have reported the use of reflections off mirror pyramids to capture high-resolution, single-viewpoint, and wide-FOV images. Using a dual mirror pyramid (DMP) panoramic camera as an example, in this paper, we examine how the pyramid geometry, and the selection and placement of imager clusters can be optimized to maximize the overall panoramic FOV, sensor utilization efficiency, and image uniformity. The analysis can be generalized and applied to other pyramid-based designs.

Algorithms↗
PubMed2004

Reducing SVM classification time using multiple mirror classifiers.

We propose an approach that uses mirror point pairs and a multiple classifier system to reduce the classification time of a support vector machine (SVM). Decisions made with multiple simple classifiers formed from mirror pairs are integrated to approximate the classification rule of a single SVM. A coarse-to-fine approach is developed for selecting a given number of member classifiers. A clustering method, derived from the similarities between classifiers, is used for a coarse selection. A greedy strategy is then used for fine selection of member classifiers. Selected member classifiers are further refined by finding a weighted combination with a perceptron. Experiment results show that our approach can successfully speed up SVM decisions while maintaining comparable classification accuracy.

Journal Article↗
PubMed1996

Fibular dimelia and mirror foot without associated anomalies.

Fibular dimelia with mirror foot is a rare anomaly that may be associated with additional anomalies such as ulnar dimelia, facial abnormalities and sacrococcygeal teratoma. We report a female child with unilateral tibial aplasia, ipsilateral duplication of fibula and calcaneus, and mirror polydactyly of the foot without associated abnormalities.

Female↗
PubMed2000

Binding of Tamm-Horsfall protein to complement 1q measured by ELISA and resonant mirror biosensor techniques under various ionic-strength conditions.

The purpose of the present study was to quantify the binding affinity between Tamm-Horsfall protein (THP) and complement 1q (C1q) using ELISA and a resonant mirror biosensor. In ELISA, immobilized THP was incubated with soluble C1q under both low and physiological ionic-strength conditions. Tamm-Horsfall protein bound C1q with an equilibrium dissociation constant (KD) of 1.9 +/- 0.6 nmol/L in low ionic-strength Tris buffers (20 mmol/L NaCl, pH 7.5) and with a lower affinity (KD of 13.4 +/- 4.7 nmol/L) in physiological-strength Tris buffers (154 mmol/L NaCl, pH 7.5). A resonant mirror biosensor, which monitors binding events in real-time, was used to quantify the KD of this reaction, as well as to estimate the kinetic parameters. In these studies, THP and C1q bound with an association rate constant, kass, of 1.25 x 105 L/mol per s and a dissociation rate constant, kdiss, of 0.002-0.005/s. The calculated KD for the THP/C1q binding in low ionic-strength buffers was higher (averages of 10-15 nmol/L) than that obtained by the ELISA, while physiological ionic-strength buffers still reduced the affinity of this binding by an order of magnitude. In conclusion, THP consistently bound C1q with high affinity using several techniques. At least a portion of this interaction involved electrostatic events, as demonstrated by the influence of ionic strength on the binding affinity.

Adjuvants, Immunologic↗
PubMed1983

Tachistoscopic recognition of normal and mirror images of Kana and Kanji characters.

Accuracy of recognition was investigated for normal and mirror images of Kana (syllabic symbols) and Kanji (ideographic symbols) characters tachistoscopically presented in the left and right visual fields in normal right-handed Japanese subjects. A significant right field superiority was obtained for the recognition of each type of normal letter. In the case of mirrored letters, Kanji characters were better recognized in the right field while no lateral asymmetry for the recognition of Kana characters was shown. The results indicated that Kanji processing is somewhat different from the processing of Kana characters.

Adult↗
PubMed2005

Quantitative evaluation of mirror movements in adults with focal brain lesions.

Mirror movements (MM), involuntary movements of homologous muscles opposite to unilateral limb activity, decrease in the course of motor development, but may reappear in adults after brain damage. To better characterize this type of acquired MM, grip forces of 36 healthy subjects and 35 patients suffering from focal brain lesions were compared. Holding force transducers in a pinch grip between thumb and index fingers of each hand, subjects had to repeatedly change the grip force in one hand, whilst the other (mirror) hand just had to prevent the manipulandum from dropping. In a second task, force changes had to be produced either in a symmetric or in an antiparallel manner. No significant group differences between patients and controls in the extent of coupling were found. During unimanual squeezing, only six patients had a co-activation in the pathologic range. Whilst performing bimanual asymmetric grip force changes, pathologic coupling was seen only in five patients. No association was found between the presence of pathologic MM and clinical or neuroanatomical features. Brain lesions in adults seem only rarely to be associated with pathologic MM. They might be non-specific and not related to the characteristics of the lesion.

Adolescent↗
PubMed2001

Physiological tremor in human subjects with X-linked Kallmann's syndrome and mirror movements.

Human physiological tremor consists of mechanical-reflex and neurogenic components. The origin of the neurogenic component, classically detected in the frequency range 7-12 Hz, has been much debated. We have studied six subjects with X-linked Kallmann's syndrome (XKS) and mirror movements. In these subjects unilateral magnetic brain stimulation results in abnormal bilateral EMG responses. Furthermore, abnormal sharing of central nervous inputs between the left and right motoneurone pools results in both abnormal motor unit synchronisation between left and right EMGs and abnormal sharing of long but not short-latency cutaneomuscular reflexes. XKS subjects with mirror movements thus provide a model for studying the central origin of physiological tremor. During sustained co-extension of the left and right index fingers, simultaneous finger tremor and extensor indicis (EI) EMGs were recorded and cross-correlated. The tremor and EMG signals were also subjected to time and frequency domain analysis.Results of frequency domain analysis between ipsilateral finger tremor and EI EMG were similar for both control and XKS subjects. However, in contrast to the controls, short-term synchronisation of left and right EI motor unit activity and significant coherence between left and right EMG, left and right tremor, left EMG and right tremor and right EMG and left tremor were found in XKS subjects. The frequency range (6-40 Hz) and coherence values between left and right were similar to ipsilateral coherence values of rectified EMG and tremor. These data provide strong evidence to support the hypothesis that the neurogenic component of physiological tremor is supraspinal in origin and ranges from 6 to 40 Hz.

Adult↗
PubMed1981

Absence of seizures or mirror foci in experimental epilepsy after excision of alumina and astrogliotic scar.

In 15 rhesus monkeys (Macaca mulatta) made epileptic by the sensorimotor cortical injection of alumina, the roles of alumina and of "mirror foci" were investigated by serial surgical excisions of the granuloma, surrounding epileptic focus, and contralateral homotopic sensorimotor cortex. Electroencephalographic and electrocorticographic recordings documented foci and transmitted contralateral epileptic activity. After the granuloma was removed, seizures continued but without alumina. After the epileptic cortex was removed, no seizure activity remained and no contralateral independent foci occurred. These findings indicate that the epilepsy incident to alumina injection into the sensorimotor cortex in monkey is not dependent on the continual presence of alumina and is not associated with independent or "mirror foci."

Aluminum Hydroxide↗
PubMed1984

The relevance of secondary epileptogenesis to the treatment of epilepsy: kindling and the mirror focus.

Human beings with partial epilepsy and demonstrable cerebral lesions show, in addition to ipsilateral epileptiform EEG discharges, apparently independent epileptiform discharges from the opposite hemisphere. Patients with apparent unilateral focal onset of their partial seizures but without demonstrable lesions also frequently display what appear to be bilaterally independent EEG foci. When surgical treatment or medical prognosis is considered and there is no demonstrable lesion, the decision of which of the two apparent foci is primarily responsible for the seizures is often difficult. Even with a known structural lesion the question arises whether, following its removal, the contralateral focus will persist and will be epileptogenic. Two related experimental phenomena bear directly on these questions- kindling and the mirror focus. This presentation looks critically at existing evidence and finds that it fails to support the idea that kindling and the mirror focus have roles in human epilepsy that currently should influence clinical decisions.

Adult↗
PubMed2006

Ictal brain hyperperfusion contralateral to seizure onset: the SPECT mirror image.

PURPOSE: Ictal single-photon emission computed tomography (SPECT) may help localize the seizure-onset zone (SOZ) by detecting changes in regional cerebral blood flow induced by epileptic discharges. This imaging method also reveals hyperperfusions in areas of seizure propagation, including the hemisphere contralateral to the SOZ. We have studied the occurrence, the topography, and the clinical value of such contralateral ictal hyperperfusion areas (HPAs). METHODS: We examined data from presurgical evaluations of 36 consecutive patients with pharmacoresistant partial epilepsy of various localizations. Ictal and interictal SPECT examinations were made with 99mTc-ECD, and the scans were processed for coregistration, normalization, subtraction, and merging with MRI images. RESULTS: Contralateral HPAs were observed in 72% of the patients: 50% of mesiotemporal epilepsy cases with hippocampal sclerosis, 85.7% of the other mesiotemporal epilepsies, 85.7% of neocortical lateral temporal epilepsies, and 87.5% of extratemporal epilepsies. Contralateral HPAs were usually symmetrical to the SOZ, forming a mirror image, observed in 57.1% of the patients. They could be slightly asymmetrical in mesiotemporal epilepsies, perhaps because of the particular anatomic pathways linking temporal lobes. In neocortical epilepsies, they were located in the cortex homotopic to the SOZ. CONCLUSIONS: We show that the symmetrical nature of the mirror image usually does not disturb SPECT interpretation. It can confirm the location of the SOZ (11 patients) and even occasionally improve the precision of its definition (nine patients) by restraining several potential SOZ-related HPAs to a single one or by permitting a restricted localization of the SOZ in a large HPA.

Brain↗
PubMed1994

Radiofrequency catheter ablation of sustained intraatrial reentrant tachycardia in a patient with mirror-image dextrocardia.

INTRODUCTION: There has been limited experience with radiofrequency catheter ablation in patients with dextrocardia. This report describes a 37-year-old man who had secundum type atrial septal defect, mirror-image dextrocardia, and drug-refractory atrial tachycardia, in whom catheter-mediated radiofrequency energy successfully eliminated the tachycardia without complication. METHODS AND RESULTS: On electrophysiologic study, the atrial tachycardia could be induced and terminated by atrial extrastimulation or rapid atrial pacing. Mixed resetting response pattern and manifest entrainment were also demonstrated. These findings suggested that the mechanism of atrial tachycardia might be related to reentry with an excitable gap. Because of the mirror-image dextrocardia, biplane fluoroscopy was adjusted to the right anterior oblique (RAO) 60 degrees and left anterior oblique (LAO) 30 degrees positions. Inducibility of the tachycardia was completely abolished after the sixth application of radiofrequency current (30 W). It was noted that the successful electrogram preceded the onset of P wave during atrial tachycardia by about 40 msec. CONCLUSION: This report presents another case in which radiofrequency catheter ablation was used in a patient with dextrocardia. Atrial tachycardia in patients with congenital heart disease may be difficult to control pharmacologically; however, the use of radiofrequency catheter ablation could be recommended as an alternative to medication and surgery.

Adult↗
PubMed1994

Discourses in the mirrored room: a postmodern analysis of therapy.

A postmodern approach is used to examine the discourses that circulate in the therapy room. Dominant discourses support and reflect the prevailing ideologies in the society. Three ready examples concern gender relations: the male sex drive discourse, the permissive discourse, and the marriage-between-equals discourse. I point out how the therapy room is a mirrored room that can reflect back only the discourses brought to it by the family and therapist. There is a predetermined content in the conversation of therapy: that provided by the dominant discourses of the language community and culture. I suggest that therapists need to develop a reflexive awareness if muted discourses are to enter the mirrored room.

Adolescent↗
PubMedDate not supplied

Morphology and development of left-handed singlets derived from mirror-image doublets of Stylonychia mytilus.

Mirror-image doublets of Stylonychia mytilus include 2 sets of cortical structures, one with the normal "right-handed" (RH) arrangement, the other with a reversed "left-handed" (LH) arrangement. These sets, however, are incomplete, with certain structures, most notably cirri of the right marginal type, missing near the line of symmetry. When a mirror-image doublet is bisected longitudinally to separate the RH and LH components physically, each fragment undergoes a regeneration process that restores a complete set of cortical structures, including the previously missing cirri of the right marginal type. In the resulting LH cell, all ciliary structures are present in an arrangement that is globally reversed in relation to that found in RH cells; in particular, marginal cirri of the left-marginal type are formed at the cell's right margin, and marginal cirri of the right-marginal type are produced at the cell's left margin. Whereas the regenerated RH fragment always divides and initiates a clone of normal singlets, the LH fragment, though structurally nearly complete, in all cases eventually dies without dividing. The cause of death is starvation due to the formation of an abnormal oral apparatus. In the Discussion, we consider the nature and consequences of a reversal of global positional information.

Animals↗
PubMed1980

The variable angle-mirror, a new tool for the study of ocular dominance and eye fixation.

A simple tool for studying optical dominance consisting of two plane mirrors moveably fixed to one another was developed. The patient looks straight ahead at the reflection of his own face and observes which eye is covered by the joint between the two mirror halves. By changing the angle a further checkup on eye dominance can be obtained. The method is simple and gives us a quick idea of the eye dominance.

Dominance, Cerebral↗