Search results for "SYSTEMS"
showing 10 items of 11952 documents
Optical factors influencing the amplitude of accommodation
2017
AbstractThe purpose of this work was to find plausible predictors among optical parameters that may explain the inter-individual differences in subjective amplitude of accommodation not explained by age. An exploratory multivariable regression analysis was carried out retrospectively on a dataset with 180 eyes from 97 subjects (ages ranged from 20 to 58years). Subjective amplitudes of accommodation were recorded with the use of a custom-made Badal system. A commercial aberrometer was used to obtain each eye’s wavefront during the full range of accommodation. The plausible predictors under study were pupil diameter in the unaccommodated eye, its reduction with accommodation; fourth- and six-…
Difficult memory task during postural tasks of various difficulties in young and older people: A pilot study
2007
Abstract Objective This study examined the effects of a difficult and individually tailored additional cognitive task on postural stability and electromyographic (EMG) activities of the ankle dorsi- and plantar-flexors, in young and older individuals performing postural tasks of varying difficulties. Methods Eight young (mean age = 24 years) and eight older (74 years) men took part in the investigation. Centre of pressure velocity and surface EMG of ankle joint muscles were both examined during various postural conditions. Results The main findings suggested that high levels of muscle activity were a characteristic of age-related declines in postural stability. Moreover, during the complex …
Localization of Congenital Tegmen Tympani Defects
2007
Objective: This study sets out to demonstrate the normal developmental steps of the tegmen tympani and thus explains the typical localization of congenital tegmental defects. Specimens: For this study, 79 macerated and formalin-fixed human temporal bones from 14th fetal week to adults were observed and prepared. Intervention: Macroscopic and microscopic examination of the prenatal and postnatal changes of the tegmen tympani during its development. Main Outcome Measure: Temporal bones from 14th fetal week to adults underwent descriptive anatomic studies to understand the normal development of the tegmen tympani and to find a possible cause of its congenital defects. Results: The medial part …
Stable aesthetic standards delusion: changing 'artistic quality' by elaboration.
2014
The present study challenges the notion that judgments of artistic quality are based on stable aesthetic standards. We propose that such standards are a delusion and that judgments of artistic quality are the combined result of exposure, elaboration, and discourse. We ran two experiments using elaboration tasks based on the repeated evaluation technique in which different versions of the Mona Lisa had to be elaborated deeply. During the initial task either the version known from the Louvre or an alternative version owned by the Prado was elaborated; during the second task both versions were elaborated in a comparative fashion. After both tasks multiple blends of the two versions had to be …
Colour Constancy in Goldfish and Man: Influence of Surround Size and Lightness
2002
Colour constancy was investigated by using a series of 10 simultaneously presented surface colours ranging in small steps from green through gray to red – purple. Goldfish were trained to select one medium test field when the entire setup was illuminated with white light. In the tests, either red or green illumination was used. Colour constancy, as inferred from the choice behaviour, was perfect under green illumination when the test fields were presented on a gray or a white background, but imperfect on a black background. Under red illumination and a white background, however, colour constancy was overcompensated. Here, a colour contrast effect was observed. The influence of background l…
Dopamine in amygdala gates limbic processing of aversive stimuli in humans
2008
Dopamine is known to contribute to the amygdala-mediated aversive response, where increased dopamine release can augment amygdala function. Combining fMRI and PET imaging techniques, Kienast et al. present findings that suggest a functional link between anxiety temperament, dopamine storage capacity and emotional processing in the amygdala. Dopamine is released under stress and modulates processing of aversive stimuli. We found that dopamine storage capacity in human amygdala, measured with 6-[18F]fluoro-L-DOPA positron emission tomography, was positively correlated with functional magnetic resonance imaging blood oxygen level–dependent signal changes in amygdala and dorsal anterior cingula…
Deterministic chaos and the first positive Lyapunov exponent: a nonlinear analysis of the human electroencephalogram during sleep
1993
Under selected conditions, nonlinear dynamical systems, which can be described by deterministic models, are able to generate so-called deterministic chaos. In this case the dynamics show a sensitive dependence on initial conditions, which means that different states of a system, being arbitrarily close initially, will become macroscopically separated for sufficiently long times. In this sense, the unpredictability of the EEG might be a basic phenomenon of its chaotic character. Recent investigations of the dimensionality of EEG attractors in phase space have led to the assumption that the EEG can be regarded as a deterministic process which should not be mistaken for simple noise. The calcu…
Different KIRs Confer Susceptibility and Protection to Adults with Latent Autoimmune Diabetes in Latvian and Asian Indian Populations
2008
KIRs (killer Ig-like receptors) expressed on natural killer (NK) cells are an important component of innate (and adaptive) immunity. They are either activatory or inhibitory, and certain KIRs are known to interact with specific motifs of HLA Class I molecules, which is very crucial in determining whether a cell is targeted to lysis or otherwise. Latent autoimmune diabetes in adults (LADA) is a slowly progressive form of autoimmune diabetes, with an adult onset (>30 years). Because autoantibodies and autoimmunity involved are involved in the etiology of LADA, KIRs might play an important role in conferring susceptibility to or protection against the disease. The purpose of this study was to …
Specific association of IL17A genetic variants with panuveitis.
2015
Background/aims A pathogenic role of Th17 cells in uveitis has become clear in recent years. Therefore, in the present study, we aimed to evaluate the possible influence of the IL 17A locus on susceptibility to non-anterior uveitis and its main clinical subgroups. Methods Five IL17A polymorphisms (rs4711998, rs8193036, rs3819024, rs2275913 and rs7747909), selected by tagging, were genotyped using TagMan assays in 353 Spanish patients with non-anterior uveitis and 1851 ethnically matched controls. Results The case/control analysis yielded a consistent association between two of the analysed genetic variants, rs8193036 and rs2275913, and the presence of panuveitis under a dominant model (p(FD…
Health-Related Physical Activity Levels in Spanish Youth and Young Adults
2014
The aim of this study was to analyze the current physical activity (PA) levels in youth and young adults from Granada, Spain, and to assess if they accomplish the recommendations for healthy PA. A sample of 1,832 boys and 1,840 girls was administered the International Physical Activity Questionnaire. Results showed that most of the children (72.2%) and adolescents (56.4%) reached the recommended PA levels, whereas only 40% of young adults achieved recommended levels of PA. The most active were students from Primary schools, whereas university students were the least active. Youth of college and university ages were found to be at higher risk for engagement in PA.