Search results for "Eye"

Cerebellar learning of bio-mechanical functions of extra-ocular muscles: modeling by artificial neural networks

2003

A control circuit is proposed to model the command of saccadic eye movements. Its wiring is deduced from a mathematical constraint, i.e. the necessity, for motor orders processing, to compute an approximate inverse function of the bio-mechanical function of the moving plant, here the bio-mechanics of the eye. This wiring is comparable to the anatomy of the cerebellar pathways. A predicting element, necessary for inversion and thus for movement accuracy, is modeled by an artificial neural network whose structure, deduced from physical constraints expressing the mechanics of the eye, is similar to the cell connectivity of the cerebellar cortex. Its functioning is set by supervised reinforceme…

Cooling of the cerebellar interpositus nucleus abolishes somatosensory cortical learning-related activity in eyeblink conditioned rabbits.

2005

Nictitating membrane movement and multiple-unit activity in the somatosensory cortex were recorded from rabbits during paired (N = 6) and unpaired (N = 5) presentations of a tone conditioned stimulus (CS) and an airpuff unconditioned stimulus (US). A behavioural conditioned response (CR) to the CS and an accompanying neural response in the somatosensory cortex developed only in the paired group. Inactivation of the cerebellar interpositus nucleus abolished both the acquired CR and the accompanying neural response. However, the CS facilitated both behavioural and neural responses to the US during the inactivation. Thus, the absence of the CR could not be accounted for by the general inabilit…

The role of the claustrum in the bilateral control of frontal oculomotor neurons in the cat.

1991

The effect of claustrum (CL) stimulation on the spontaneous unitary activity of ipsi and contralateral frontal oculomotor neurons, was studied in chloralose-anaesthetized cats. A total of 205 units was bilaterally recorded in the medial oculomotor area, homologous of the primate "frontal eye fields"; 127 neurons were identified as projecting to the superior colliculus; for 33 of these last units stimulation of the ipsilateral CL provoked an excitatory effect lasting 10-25 ms and appearing with a latency of 5-15 ms; on 8 units the excitatory effect was followed by an inhibition lasting 100-250 ms. Ninety-eight of the 127 neurons were also tested through activation of the contralateral CL: 13…

Associated arterial and venous cerebral manifestations in Behçet's disease

2018

Behcet's disease is a rare multisystemic vasculitis with an etiology that is still unknown. Neurological manifestations may be seen in approximately 5-15% of patients, and both parenchymal and extraparenchymal neurological involvement has been described. When cerebral venous thrombosis (CVT) is the main extraparenchymal manifestation of Behcet's disease, the condition is then dubbed "angio-Behcet's syndrome". However, arterial involvement is extremely rare, with only one reported case of vasculo-neuro-Behcet's disease, characterized by both venous and intracranial arterial involvement - until now. This report is of two patients diagnosed with Behcet's disease characterized by the concomitan…

Embden-Meyerhof-Parnas Pathway

2011

Baeyer−Villiger Oxidation with Potassium Peroxomonosulfate Supported on Acidic Silica Gel

2005

[reaction: see text] Potassium peroxomonosulfate deposited onto silica SiO2 x KHSO5 efficiently reacts with ketones in dichloromethane at room temperature to give the corresponding esters or lactones in quantitative yields. This method avoids hydrolysis of the reaction products. The Baeyer-Villiger reaction is catalyzed by potassium hydrogensulfate present in the supported reagent.

Retrobulbäre Bestrahlung bei endokriner Orbitopathie - Erfahrungen im Langzeitverlauf

2002

Background Significance of retrobulbar irradiation in patients suffering form Graves' ophthalmopathy, though established since almost one century, is subject of scientific debate. The present study investigated the effect of retrobulbar irradiation using a standardized protocol focussing on long term results. Patients and methods Between 1981 and 1997, 104 patients treated by retrobulbar irradiation (10 to 20 Gray) due to Graves' disease. Twenty-nine of these underwent irradiation as sole treatment (mean follow-up 57 months), while in the remaining 75, it was combined with a systemic steroid treatment (mean follow-up 40 months). Patients were evaluated regarding proptosis, intraocular press…

Diabetic retinopathy: Monitoring of the macro and microrheological parameters after oral administration of a single dose of calcium dobesilate (Doxiu…

1991

Comparative analysis of short tandem repeats and single nucleotide polymorphisms on the Y-chromosome in Germans, Chinese and Thais.

2003

We have typed genomic DNA samples from 95 individuals from Western Germany, 78 individuals from Bangkok/Thailand and 56 individuals from Chengdu/China for 11 Y-chromosomal diallelic polymorphisms and eight short tandem repeat (STR) systems. For single nucleotide polymorphism (SNP) analysis, a rapid method was applied using the single base extension technology (minisequencing) in combination with capillary electrophoresis. PCR products for SRY-8299, Tat, SRY2627, 92R7, SRY1532, M9, M13, M17/M19 and M20 were pooled and used as templates for the commercially available SNaPshot kit. In addition to these ten SNPs we also tested the Y-chromosomal diallelic Alu repeat insertion DYS287 (YAP) by aga…

Carotenoid binding sites in LHCIIb

2000

The major light-harvesting complex of photosystem II can be reconstituted in vitro from its bacterially expressed apoprotein with chlorophylls a and b and neoxanthin, violaxanthin, lutein, or zeaxanthin as the only xanthophyll. Reconstitution of these one-carotenoid complexes requires low-stringency conditions during complex formation and isolation. Neoxanthin complexes (containing 30–50% of the all-trans isomer) disintegrate during electrophoresis, exhibit a largely reduced resistance against proteolytic attack; in addition, energy transfer from Chl b to Chl a is easily disrupted at elevated temperature. Complexes reconstituted in the presence of either zeaxanthin or lutein contain nearly …