• Title/Summary/Keyword: Cerebellar

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CMAC (Cerebellar Model Arithmetic Controller)

  • Hwang, Heon;Choi, Dong-Y.
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.675-681
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    • 1989
  • As an adaptive control function generator, the CMAC (Cerebellar Model Arithmetic or Articulated Controller) based learning control has drawn a great attention to realize a rather robust real-time manipulator control under the various uncertainties. There remain, however, inherent problems to be solved in the CMAC application to robot motion control or perception of sensory information. To apply the CMAC to the various unmodeled or modeled systems more efficiently, It is necessary to analyze the effects of the CMAC control parameters an the trained net. Although the CMAC control parameters such as size of the quantizing block, learning gain, input offset, and ranges of input variables play a key role in the learning performance and system memory requirement, these have not been fully investigated yet. These parameters should be determined, of course, considering the shape of the desired function to be trained and learning algorithms applied. In this paper, the interrelation of these parameters with learning performance is investigated under the basic learning schemes presented by authors. Since an analytic approach only seems to be very difficult and even impossible for this purpose, various simulations have been performed with prespecified functions and their results were analyzed. A general step following design guide was set up according to the various simulation results.

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Vertigo and Sudden Hearing Loss Caused by Pontine Infarction (현훈과 돌발성 난청을 주소로 하는 뇌교경색)

  • Hyun, Min-Kyung;Sin, Won-Yong;Kim, Mi-Rang;Shin, Hyeon-Cheol;Jeong, Ji-Cheon;Yoon, Cheol-Ho;Jeong, Byoung-Mu
    • The Journal of Internal Korean Medicine
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    • v.25 no.4
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    • pp.200-206
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    • 2004
  • Anterior inferior cerebellar artery(AICA) is a branch of the basilar artery which supplies the bloods for ventrolateral cerebellum and the lateral tegmentum of the lower two-thirds of pons. AICA occlusion can cause such symptoms as acute-onset unilateral deafness, vertigo, facial weakness and ataxia. A case of sudden hearing loss, facial palsy and vertigo caused by AICA territory infarction recently presented itself. Korean Oriental and Western medical therapy were applied in combination. Facial palsy and vertigo improved, but hearing loss did not improve. This case is reported with a brief overview of related literatures.

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Positional Cloning and Phenotypic Characterization of a New Mutant Mouse with Neuronal Migration Abnormality

  • Park, Chankyu;Ackerman, Susan-L
    • Proceedings of the KSAR Conference
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    • 2001.10a
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    • pp.14-17
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    • 2001
  • Positional cloning (map-based cloning) of mutations or genetic variations has been served as an invaluable tool to understand in-vivo functions of genes and to identify molecular components underlying phenotypes of interest. Mice homozygous for the cerebellar deficient folia (cdf) mutation are ataxic, with cerebellar hypoplasia and abnormal lobulation of the cerebellum. In the cdf mutant cerebellum approximately 40% of Purkinje cells are ectopically located within the white matter and the inner granule cell layer (IGL). To identify the cdf gene, a high-resolution genetic map for the cdf-gene-encompassing region was constructed using 1997 F2 mice generated from C3H/HeSnJ-cdf/cdf and CAST/Ei intercross. The cdf gene showed complete linkage disequilibrium with three tightly linked markers D6Mit208, D6Mit359, and D6Mit225. A contig using YAC, BAC, and P1 clones was constructed for the cdf critical region to identify the gene. A deletion in the cdf critical region on chromosome 6 that removes approximately 150kb of DNA was identified. A gene associated with this deletion was identified using cDNA selection. cdf mutant mice with the transgenic copy of the identified gene restored the brain abnormalities of the mutant mice. The positional cloning of cdf gene provides a good example showing the identification of a gene could lead to finding a new component of important molecular pathways.

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LEARNING PERFORMANCE AND DESIGN OF AN ADAPTIVE CONTROL FUCTION GENERATOR: CMAC(Cerebellar Model Arithmetic Controller)

  • Choe, Dong-Yeop;Hwang, Hyeon
    • 한국기계연구소 소보
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    • s.19
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    • pp.125-139
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    • 1989
  • As an adaptive control function generator, the CMAC (Cerebellar Model Arithmetic or Articulated Controller) based learning control has drawn a great attention to realize a rather robust real-time manipulator control under the various uncertainties. There remain, however, inherent problems to be solved in the CMAC application to robot motion control or perception of sensory information. To apply the CMAC to the various unmodeled or modeled systems more efficiently, it is necessary to analyze the effects of the CMAC control parameters on the trained net. Although the CMAC control parameters such as size of the quantizing block, learning gain, input offset, and ranges of input variables play a key role in the learning performance and system memory requirement, these have not been fully investigated yet. These parameters should be determined, of course, considering the shape of the desired function to be trained and learning algorithms applied. In this paper, the interrelation of these parameters with learning performance is investigated under the basic learning schemes presented by authors. Since an analytic approach only seems to be very difficult and even impossible for this purpose, various simulations have been performed with pre specified functions and their results were analyzed. A general step following design guide was set up according to the various simulation results.

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Selective Suppression of a Subset of Bax-dependent Neuronal Death by a Cell Permeable Peptide Inhibitor of Bax, BIP

  • Kim, Soo-Young;Kim, Hyun;Sun, Woong
    • Animal cells and systems
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    • v.12 no.4
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    • pp.211-217
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    • 2008
  • Bax, a pro-apoptotic member of Bcl-2 family proteins, plays a central role in the mitochondria-dependent apoptosis. Apoptotic signals induce the translocation of Bax from cytosol into the mitochondria, which triggers the release of apoptogenic molecules such as cytochrome C and apoptosis-inducing factor, AIF. Bax-inhibiting peptide(BIP) is a cell permeable peptide comprised of five amino acids designed from the Bax-interaction domain of Ku70. Because BIP inhibits Bax translocation and Bax-mediated release of cytochrome C, BIP suppresses Bax-dependent apoptosis. In this study, we observed that BIP inhibited staurosporine-induced neuronal death in cultured cerebral cortex and cerebellar granule cells, but BIP failed to rescue granule cells from trophic signal deprivation-induced neuronal death, although both staurosporine-induced and trophic signal deprivation-induced neuronal death are dependent on Bax. These findings suggest that the mechanisms of the Bax activation may differ depending on the type of cell death induction, and thus BIP exhibits selective suppression of a subtype of Bax-dependent neuronal death.

Intracranial Metastases of Cervical Intramedullary Low-Grade Astrocytoma without Malignant Transformation in Adult

  • Jang, Se-Youn;Kong, Min-Ho;Song, Kwan-Young;Frazee, John G.
    • Journal of Korean Neurosurgical Society
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    • v.45 no.6
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    • pp.381-385
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    • 2009
  • The first case of intracranial metastases of a cervical intramedullary low-grade astrocytoma without malignant transformation in adult is presented in this report. Seven years ago, a 45 year-old male patient underwent biopsy to confirm pathologic characteristics and received craniocervical radiation and chemotherapy for a grade II astrocytoma in the cervical spinal cord. Two years later, posterior fusion was necessary for progressive kyphosis in the cervical spine. He was well for approximately 7 years after the primary surgery. Two months ago, he presented with partial weakness and incoordination with gait difficulty. MRI Scan demonstrated multiple small lesions in the cerebellar vermis and left hemisphere. After suboccipital craniectomy and posterior cervical exposure, the small masses in the cerebellar vermis and hemispheres were excised to a large extent by guidance of an intraoperative navigation system. The tumor at the cervical and brain lesions was classified as an astrocytoma (WHO grade II). When a patient with low-grade astrocytoma in the spinal cord has new cranial symptoms after surgery, radiaton, and chemotherapy, the possibility of its metastasis should be suspected because it can spread to the intracranial cavity even without malignant transformation as shown in this case.

A Family of Dentatorubropallidoluysian Atrophy (Dentatorubropallidoluysian Atrophy 일가족)

  • Chung, Ji-Yoon;Park, Mee-Young;Lee, Jun;Yoon, Jun-Pil;Park, Hyun-Jung
    • Journal of Yeungnam Medical Science
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    • v.23 no.1
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    • pp.118-123
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    • 2006
  • Dentatorubropallidoluysian atrophy (DRPLA) is a rare neurodegenerative disorder usually inherited in an autosomal dominant pattern. DRPLA has been shown to be associated with expansion of an unstable cytosine-adenine-guanine (CAG) trinucleotide repeat in a gene on chromosome 12p. We evaluated a family with DRPLA that affected three members; A 35-year-old female presented with seven year history of gait ataxia, dysarthria and mild cognitive impairment. The MRI of the brain revealed diffuse cerebellar atrophy with an incidental lipoma in the midbrain. Her 30-year-old brother presented with progressive cerebellar ataxia that developed at the age of 20. Her grandmother and mother were reported to have developed ataxia during the late period of their life, and died at the age of 60 and 55, respectively. The demonstration of an expanded CAG repeat in the gene for DRPLA was used to confirm the diagnosis.

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Immunohistochemical Localization of Anoctamin 1 in the Mouse Cerebellum

  • Park, Yong Soo;Jeon, Ji Hyun;Lee, Seung Hee;Paik, Sun Sook;Kim, In-Beom
    • Applied Microscopy
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    • v.48 no.4
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    • pp.110-116
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    • 2018
  • Since a transmembrane protein, TMEM16A, also called anoctamin 1 (ANO1), was identified as a bona fide calcium ($Ca^{2+}$)-activated chloride ($Cl^-$) channel (CaCC), there have been many reports on its expression and function. However, limited information on ANO1 expression and function in the brain is still available. In this study, we tried to reexamine expression patterns of ANO1 in the mouse cerebellum and further characterize ANO1-expressing components by immunohistochemical analyses. Strong ANO1 immunoreactivity was observed as large puncta in the granule cell layer and weak to moderate immunoreactivities were observed as small puncta in the molecular and Purkinje cell layers. Double-label experiments revealed that ANO1 did not colocalize with cerebellar neuronal population markers, such as anti-calbindin and anti-NeuN, while it colocalized or intermingled with a presynaptic marker, anti-synaptophysin. These results demonstrate that ANO1 is mainly localized at presynaptic terminals in the cerebellum and involved in synaptic transmission and modulation in cerebellar information processing.

Coil Embolization of Ruptured Proximal Posterior Inferior Cerebellar Artery Aneurysm with Contralateral Retrograde Approach for LVIS Jr. Intraluminal Support Deployment

  • Kim, Dong Sub;Sung, Jae Hoon;Lee, Dong Hoon;Yi, Ho Jun
    • Journal of Cerebrovascular and Endovascular Neurosurgery
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    • v.20 no.4
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    • pp.235-240
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    • 2018
  • The safety and feasibility of simple coil embolization and stent deployment for the treatment of posterior inferior cerebellar artery (PICA) aneurysms, as well as their radiologic and clinical results, have not been adequately understood. Especially, if dissecting aneurysm of proximal PICA is associated with small caliber PICA and stenosis of ipsilateral vertebral artery orifice (VAO), endovascular coiling with saving of PICA is not always easy. This 64-year-old man presented with subarachnoid hemorrhage due to a ruptured dissecting aneurysm of left proximal PICA. The aneurysm was irregularly fusiform in nature with a shallow PICA orifice (1.4 mm) and narrow caliber (0.9-1.5 mm). Moreover, the ipsilateral VAO showed severe stenosis (1.8 mm). We performed bifemoral puncture and chose additional route from right vertebral artery to left vertebrobasilar junction for retrograde approach and deployment of LVIS Jr. intraluminal support at proximal PICA. And then, the antegrade approach and coiling of aneurysm was done. Despite of transient thrombus of PICA, the aneurysm was successfully secured with preservation of whole PICA course. For preservation of narrow PICA with ipsilateral VAO stenosis, the contralateral approach and deployment of LVIS Jr. intraluminal support may be considered.

Delayed Clinical Signs Associated with Cerebellar Lesion in Holstein Calf Infected with Bovine Viral Diarrhea Virus

  • Choi, Woojae;Ro, Younghye;Hong, Leegon;Kim, Eunkyung;Choe, Eunhui;Kim, Danil
    • Journal of Veterinary Clinics
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    • v.39 no.1
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    • pp.38-43
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    • 2022
  • A 5-month-old Holstein downer calf was presented, and bovine viral diarrhea virus was detected in the feces and the cerebrospinal fluid. Combined treatment of recombinant bovine somatotropin (rBST) administration and standing rehabilitation had been performed for two months, and the calf could maintain the standing position for a while. However, the symptoms were not improved, and the calf died due to ruminal tympany and aspiration pneumonia. Megaesophagus, abomasal ulcer, and a normal-sized but softened cerebellum were observed in clinical necropsy. Improvement of symptoms was confirmed by rBST, but was not reached the complete recovery of gait and standing position.