University of Cagliari

About: University of Cagliari is a education organization based out in Cagliari, Italy. It is known for research contribution in the topics: Population & Dopamine. The organization has 11029 authors who have published 29046 publications receiving 771023 citations. The organization is also known as: Università degli Studi di Cagliari & Universita degli Studi di Cagliari.

Effect of the oral administration of tryptophan‐free amino acid mixtures on serum tryptophan, brain tryptophan and serotonin metabolism

Abstract: TRYPTOPHAN (Try) is the only amino acid circulating in plasma which is bound to serum proteins (MCMENAMY & ONCLEY, 1958). Previous studies from our (TAGLIAMONTE et al., 1971a; GESSA et al., 1972; TAGLIAMONTE et al., 1973a; 1973b) and Curzon's laboratories (KNOTT & CURZON, 1972) have shown that the concentration of free Try in serum parallels in many instances the concentration of Try in brain which, in turn, parallels the synthesis rate of brain serotonin (TAGLIAMONTE et al., 1971~; TAGLIAMONTE, et al., 1971b). On the other hand, studies on transport of amino acids from blood to brain on uptake of amino acids by brain slices GUROFF & UDENFRIEND, 1962; OLDENWRF, 1971; &HEN & LAJTHA, 1972) or synaptosomes (GRAHAME-SMITH & PARFITT, 1970) have shown that many of the aromatic acids share the same transport mechanism from blood to brain and that a high concentration of one can lower the uptake or transport of others. These considerations suggest that Try concentration in brain may depend not only on the concentration of free serumTry but also, as suggested by FERNSTROM & WURTMAN (1971), on the plasma concentration of the other amino acids competing for the same transport mechanism. In order to test this hypothesis, we studied the effect of the intragastric administration of different amino acid mixtures not containing Try, on brain Try level and serotonin metabolism. Results show that certain amino acid combinations produce a dramatic fall in Try, serotonin and 5-h ydroxyindoleacetic acid in brain and in free and total Try in serum. MATERIALS AND METHODS

Carotid Artery Wall Imaging: Perspective and Guidelines from the ASNR Vessel Wall Imaging Study Group and Expert Consensus Recommendations of the American Society of Neuroradiology

Abstract: Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis and surface irregularities using in vivo imaging techniques including sonography, CT and MR angiography, and digital subtraction angiography. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. The ability to look beyond the lumen using highly developed vessel wall imaging methods to identify plaque vulnerable to disruption has prompted an active debate as to whether a paradigm shift is needed to move away from relying on measurements of luminal stenosis for gauging the risk of ischemic injury. Further evaluation in randomized clinical trials will help to better define the exact role of plaque imaging in clinical decision-making. However, current carotid vessel wall imaging techniques can be informative. The goal of this article is to present the perspective of the ASNR Vessel Wall Imaging Study Group as it relates to the current status of arterial wall imaging in carotid artery disease.

Pollination: Rotting smell of dead-horse arum florets.

Abstract: These blooms chemically fool flies into pollinating them. Deceit by resource mimicry has evolved as a pollination strategy in several plant species1,2,3 and is particularly elaborate in a plant known as dead-horse arum (Helicodiceros muscivorus; Araceae: Aroideae), which may fool flies into pollinating it by emitting a smell like a dead animal — an important oviposition resource for these insects. Here we confirm that the composition of volatiles from these flowers and from a rotting carcass is strikingly similar and show that the pollinators respond in the same way to chemicals from both sources. This remarkably complex mimicry must have evolved to exploit insects as unrewarded pollinators.

Effects of melatonin on vascular reactivity, catecholamine levels, and blood pressure in healthy men.

Abstract: In this study it was investigated whether the oral administration of melatonin (1 mg) in comparison to placebo was able to reduce blood pressure, vascular reactivity, and catecholamines in men, as previously reported in young women. The administration of melatonin significantly reduced blood pressure, the pulsatility index in the internal carotid artery, and catecholamines levels within 90 minutes. The effect of melatonin on the artery pulsatility index was related to baseline values, being greater in men with higher baseline values. The present data indicate that melatonin may blunt the activity of the cardiovascular system and may have both physiopathologic and clinical implications.

Diversified Sensitivity-Based Undersampling for Imbalance Classification Problems

Abstract: Undersampling is a widely adopted method to deal with imbalance pattern classification problems. Current methods mainly depend on either random resampling on the majority class or resampling at the decision boundary. Random-based undersampling fails to take into consideration informative samples in the data while resampling at the decision boundary is sensitive to class overlapping. Both techniques ignore the distribution information of the training dataset. In this paper, we propose a diversified sensitivity-based undersampling method. Samples of the majority class are clustered to capture the distribution information and enhance the diversity of the resampling. A stochastic sensitivity measure is applied to select samples from both clusters of the majority class and the minority class. By iteratively clustering and sampling, a balanced set of samples yielding high classifier sensitivity is selected. The proposed method yields a good generalization capability for 14 UCI datasets.