144 research outputs found

    Mutual interaction of salinity and dietary protein level on growth, survival and body composition of narrow clawed cray fish (Astacus leptodactylus)

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    In this study Astacus leptodactylus were tested for 8 week with three practical diets containing three crude protein (30, 35 and 40%) and isoenergetic level (370kcal/100 g) in fresh water and brackish water of Caspian Sea. In this test, 6 treatments were used with three replicates in 18 fiberglass tank (110 liter). Each tank had 5 narrow clawed Cray fish (mean (±SD) individual weight=17±2.3g) and totally 90 clawed Cray fish were stocking. Result indicates mean weight of Cray fish in fresh water and brackish water were 14.82 and 12.73, respectively, that were significantly different. The highest survival occurred in interaction between protein (30%) and salinity (0) (95.55%) and lowest survival occurred in protein 40 – salinity (12) that were significantly different. The highest specific growth rate (SGR), weight gain (WG), Protein Efficiency Ratio (PER), Net Protein Utilization (NPU) and lowest Feed Conversion Ratio (FCR), demonstrated that dietary (protein 30% and fresh water) which had no significantly differences. Result of this study showed that the highest protein of body composition were in practical diet containing 30% protein and 0 salinity (freshwater) that were significantly different with other treatment

    Species identification reveals mislabeling of important fish products in Iran by DNA barcoding

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    This study reports on the molecular identification of fish species from processed products which had a priori been classified as belonging to 5 important species in Iran for human consumption. DNA barcoding using direct sequencing of an approximately 650bp of mitochondrial Cytochrome oxidase subunit I (COI) gene revealed incorrect labeling of Narrow-barred Spanish mackerel samples. High occurrence of fraudulent fishery products, if left unchecked, can pose a negative impact on the economy. This investigation adds further concern on the trading of processed fish products in Iran from both health and conservation points of view

    Physiological and biochemical responses of Damask rose (Rosa damascena Miller) to potassium silicate application under water deficit stress

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    In this field experiment, the effect of potassium silicate (PS) on the physiological and biochemical responses of Damask rose was investigated under the water deficit stress. The treatments were four levels of irrigation water application including 100, 75, 50 and 25% plant water requirement (PWR) and potassium silicate at three rates (0, i.e., just pure water, 0.2 and 0.4%), once (in spring or summer) or twice (once in spring and once in summer) during the plant growth. The results showed that with irrigation of 75% of plant water requirement significantly reduced the concentration of chlorophyll a (Chl a, 170%), chlorophyll b (Chl b, 163%) and carotenoids (91%), the leaf relative water content (RWC, 14.8%) and the total flower yield (20%) as compared to control. The elevated malondialdehyde (MDA) content and ion leakage, as two indicators of oxidative damage, were observed in the plants subjected to the water deficit stress. In response to oxidative stress induced by water deficit stress, the leaf catalase (CAT, 59.5%) activity and concentration of proline (64.8%) as compared to control increased. The foliar-applied Si at two rates of 0.2 and 0.4% in spring and summer resulted in a higher concentration of Chl a (57.3% and 61.7%), Chl b (31% and 24.6%) and carotenoid content as compared to control, respectively. The increased concentration of proline and higher activity of CAT in the plants supplied with Si led to the higher leaf RWC and less intensity of oxidative damage, namely ion leakage and MDA content. According to the results, with the potassium silicate spraying in 0.2 or 0.4% both in spring and summer at the irrigation level equal to 50% of the PWR, the optimum flower yield was achieved

    Local biases drive, but do not determine, the perception of illusory trajectories

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    When a dot moves horizontally across a set of tilted lines of alternating orientations, the dot appears to be moving up and down along its trajectory. This perceptual phenomenon, known as the slalom illusion, reveals a mismatch between the veridical motion signals and the subjective percept of the motion trajectory, which has not been comprehensively explained. In the present study, we investigated the empirical boundaries of the slalom illusion using psychophysical methods. The phenomenon was found to occur both under conditions of smooth pursuit eye movements and constant fixation, and to be consistently amplified by intermittently occluding the dot trajectory. When the motion direction of the dot was not constant, however, the stimulus display did not elicit the expected illusory percept. These findings confirm that a local bias towards perpendicularity at the intersection points between the dot trajectory and the tilted lines cause the illusion, but also highlight that higher-level cortical processes are involved in interpreting and amplifying the biased local motion signals into a global illusion of trajectory perception

    Local biases drive, but do not determine, the perception of illusory trajectories

    Get PDF
    When a dot moves horizontally across a set of tilted lines of alternating orientations, the dot appears to be moving up and down along its trajectory. This perceptual phenomenon, known as the slalom illusion, reveals a mismatch between the veridical motion signals and the subjective percept of the motion trajectory, which has not been comprehensively explained. In the present study, we investigated the empirical boundaries of the slalom illusion using psychophysical methods. The phenomenon was found to occur both under conditions of smooth pursuit eye movements and constant fixation, and to be consistently amplified by intermittently occluding the dot trajectory. When the motion direction of the dot was not constant, however, the stimulus display did not elicit the expected illusory percept. These findings confirm that a local bias towards perpendicularity at the intersection points between the dot trajectory and the tilted lines cause the illusion, but also highlight that higher-level cortical processes are involved in interpreting and amplifying the biased local motion signals into a global illusion of trajectory perception

    Anger as Seeing Red

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    A class of metaphors links the experience of anger to perceptions of redness. Whether such metaphors have significant implications for understanding perception is not known. In Experiment 1, anger (versus sadness) concepts were primed and it was found that priming anger concepts led individuals to be more likely to perceive the color red. In Experiment 2, anger states were directly manipulated, and it was found that evoking anger led individuals to be more likely to perceive red. Both experiments showed that the observed effects were independent of the actual color presented. These findings extend the New Look, perceptual, metaphoric, and social cognitive literatures. Most important, the results suggest that emotion representation processes of a metaphoric type can be extended to the perceptual realm. </jats:p
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