Different reaction-times for subitizing, estimation, and texture

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Pupillometry correlates of visual priming, and their dependency on autistic traits

In paradigms of visual search where the search feature (say color) can change from trial to trials, responses are faster for trials where the search color is repeated than when it changes. This is a clear example of "priming" of attention. Here we test whether the priming effects can be revealed by pupillometry, and also whether they are related to autistic-like personality traits, as measured by the Autism-Spectrum Quotient (AQ). We repeated Maljkovic and Nakayama's (1994) classic priming experiment, asking subjects to identify rapidly the shape of a singleton target defined by color. As expected, reaction times were faster when target color repeated, and the effect accumulated over several trials; but the magnitude of the effect did not correlate with AQ. Reaction times were also faster when target position was repeated, again independent of AQ. Presentation of stimuli caused the pupil to dilate, and the magnitude of dilation was greater for switched than repeated trials. This effect did not accumulate over trials, and did not correlate with the reaction times difference, suggesting that the two indexes measure independent aspects of the priming phenomenon. Importantly, the amplitude of pupil modulation correlated negatively with AQ, and was significant only for those participants with low AQ. The results confirm that pupillometry can track perceptual and attentional processes, and furnish useful information unobtainable from standard psychophysics, including interesting dependencies on personality traits

Transfer phenomena of volatile organic compounds in thermoplastic polymers and polymer blends by supercritical carbon dioxide

The low-temperature uptake of the flavouring agents limonene and vanillin from supercritical carbon dioxide (CO2SCF) into films of a poly(ethylene terephthalate)-based copolyester (PET-G), polycaprolactam (PA6), and isotactic poly(propylene) (PP), also blended with hydrogenated oligo(cyclopentadiene) or polycaprolactam, have been investigated through thermogravimetric determination of the additive amount released in the temperature range 30-230 degrees C. The uptake of an additive strongly depends on its relative solubility in the polymer and in CO2SCF: limonene can easily be transferred into lipophilic PP-based and PET-G polymers, also due to the plastifying action of CO2SCF on PET-G, while only the more polar vanillin can be taken up by hydrophilic PA6. The CO2SCF treatment is particularly suitable for the low-temperature uptake of heat-sensitive flavours into polymeric substrates to be used in "active" packaging

Evoluzione pre e postnatale del blocco atrioventricolare congenito isolato diagnosticato in utero

We evaluated the pre- and postnatal outcome of isolated atrioventricular (AV) block detected during fetal life in order to identify factors that may affect the natural history of this lesion and to assess prenatal therapy. Over the past eight years, we consecutively evaluated 10 fetuses with complete AV block. The mean gestational age at diagnosis was 25.3 weeks and the mean heart rate was 57 bpm; two fetuses were hydropic. During pregnancy, one fetus suddenly died, while 6 out of 9 fetuses had a mean reduction in heart rate of 17.8 bpm; 4 patients had heart rate < 50 bpm. Five fetuses developed heart failure, which was severe in 2 cases and mild in 3. The mean gestational age at delivery was 31 weeks. Dexamethasone was administered to the mothers during pregnancy in 4 cases without modification of AV block and/or of heart rate, but in 3 out of 4 fetuses the general condition remained stable in spite of the reduction in heart rate in two of them. Sympathomimetic drugs were employed in 3 cases with an increase in fetal heart rate, but maternal discomfort appeared in two cases. Three newborns died during the first week of life, two of hydrops and one of persistent pulmonary hypertension. Cardiac pacing was performed in 6/9 patients within the first 8 months of life and in 3 within the first 2 days. In conclusion, morbidity and mortality are high when AV block is detected during fetal life. Negative prognostic factors are hydrops and a heart rate < 50 bpm. Pre-term delivery to enable cardiac pacing is probably the therapy of choice if gestational age is > 27-28 weeks. Sympathomimetic drugs are effective but are poorly tolerated by the mothers. Dexamethasone has no effect on AV block and/or heart rate, but may improve clinical tolerance of conduction disturbance