14 research outputs found

    Chemical composition of the brown alga Padina pavonia (L.) Gaill. from the adriatic sea

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    The chemical composition of the brown alga Padina pavonia (L.) Gaill. from the southern Adriatic Sea was investigated. Twelve sterols were identified in the sterol fraction, the main ones being cholesterol and fucosterol. The main fatty acids in the lipids were also identified.The most abundant fatty acid was palmitic acid, followed by oleic and myristic acids.The concentration of polyunsaturated fatty acids was unusually low for a marine alga. By GC/MS analysis of the volatile and polar fractions, 40 compounds were identified. Some of them probably possess defensive functions. In the volatile fraction free fatty acids, aromatic esters, benzyl alcohol and benzaldehyde predominated. Low concentrations of terpenoids, phenols and sulfur containing compounds were also identified.The nbutanol extract contained mainly fatty acids and polyols. Some of the extracts had an antibacterial activity

    Proprioceptive Movement Illusions Due to Prolonged Stimulation: Reversals and Aftereffects

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    Background. Adaptation to constant stimulation has often been used to investigate the mechanisms of perceptual coding, but the adaptive processes within the proprioceptive channels that encode body movement have not been well described. We investigated them using vibration as a stimulus because vibration of muscle tendons results in a powerful illusion of movement. Methodology/Principal Findings. We applied sustained 90 Hz vibratory stimulation to biceps brachii, an elbow flexor and induced the expected illusion of elbow extension (in 12 participants). There was clear evidence of adaptation to the movement signal both during the 6-min long vibration and on its cessation. During vibration, the strong initial illusion of extension waxed and waned, with diminishing duration of periods of illusory movement and occasional reversals in the direction of the illusion. After vibration there was an aftereffect in which the stationary elbow seemed to move into flexion. Muscle activity shows no consistent relationship with the variations in perceived movement. Conclusion. We interpret the observed effects as adaptive changes in the central mechanisms that code movement in direction-selective opponent channels

    Preparación de concentrados de ácidos grasos poliinsaturados de aceite de hígado de cazón (Squalus acanthias) del Mar Negro.

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    The fatty acid composition of the liver oil from the Black Sea dogfish Squalus acanthias, as well as its seasonal variations were determined. A scheme for concentration of polyunsaturated fatty acids from the dogfish liver oil by urea complexation was proposed. From 360g of free fatty acids a 48g concentrate was obtained, containing 7,8% C20:4, 16,4% C20:5. 9,2% C22:5 and 49,7% C22:6.Se ha determinado la composición en ácidos grasos del aceite de hígado de cazón (Squalus acanthias) del Mar Negro, así como sus variaciones estacionales. Se propone un esquema para la concentración de ácidos grasos poliinsaturados de aceite de hígado de cazón mediante complexión de urea. A partir de 360g de ácidos grasos libres se obtuvo un concentrado de 48g, que contenía 7,8% C20:4, 16,4% C20:5, 9,2% C22:5 y 49,7% C22:6

    Lateral skin stretch influences direction judgments of motion across the skin

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    The two-volume set LNCS 8618 and 8619 constitutes the refereed proceedings of the 9th International Conference EuroHaptics 2014, held in Versailles, France, in June 2014
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