323 research outputs found

    Taylor subsumes Scott, Berry, Kahn and Plotkin

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    The speculative ambition of replacing the old theory of program approximation based on syntactic continuity with the theory of resource consumption based on Taylor expansion and originating from the differential γ-calculus is nowadays at hand. Using this resource sensitive theory, we provide simple proofs of important results in γ-calculus that are usually demonstrated by exploiting Scott's continuity, Berry's stability or Kahn and Plotkin's sequentiality theory. A paradigmatic example is given by the Perpendicular Lines Lemma for the Böhm tree semantics, which is proved here simply by induction, but relying on the main properties of resource approximants: strong normalization, confluence and linearity

    The Implications of Taste and Olfaction in Nutrition and Health

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    Taste and olfaction are sensory modalities that act synergistically to orchestrate the behaviors essential for survival, such as interactions with the environment, nutrient-rich food identification, and the avoidance of noxious substances [...]

    Validation of a single liquid chromatography-tandem mass spectrometry approach for oxytetracycline determination in bull plasma, seminal plasma and urine

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    Oxytetracycline is a broad-spectrum antibiotic, which inhibits protein synthesis and is generally used for the treatment of pneumonia, shipping fever, leptospirosis and wound infections in cattle and swine. The present work proposes a novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for oxytetracycline quantification in bull plasma, seminal plasma and urine, requiring limited sample treatment before analysis. Extraction with trichloroacetic acid followed by dilution of the supernatant in mobile phase proved to be effective in all three matrices, allowing to rapidly process large batches of samples. Sharp and symmetrical peak shape was obtained using a BEH C18 reversed-phase column in a chromatographic run of just 3.5 min. The mass spectrometer operated in positive electrospray ionization mode and monitored specific transitions for oxytetracycline (461.1 → 425.8) and the internal standard demeclocycline (465.0 → 447.6). The method was validated over concentration ranges suitable for field concentrations of oxytetracycline found in each matrix, showing good linearity during each day of testing (R2 always >0.99), as also confirmed by analysis of variance (ANOVA) and lack-of-fit tests. Excellent accuracy and precision were demonstrated by calculated bias always within ±15% and CV% below 10% at all quality control (QC) levels in the three matrices. Matrix effect and recovery were investigated for both analytes, which showed consistent and comparable behaviour in each matrix. To our knowledge, this is the first validated approach for mass spectrometric determination of oxytetracycline in seminal plasma and urine. The method was successfully applied to samples collected during a pharmacokinetic study in bulls, allowing to assess the oxytetracycline concentration–time profile in plasma, seminal plasma and urine

    A polymorphism in the human gene encoding OBPIIa affects the perceived intensity of smelled odors

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    Among the factors that contribute to the physiological variability of the olfactory function of individuals, an important role seems to be played by the OBPs present in the mucus that bathes the ciliated terminals of the olfactory sensory neurons, facilitating the access of odorants to the olfactory receptors. It was recently highlighted that the rs2590498 polymorphism in the odor binding-protein (OBPIIa) gene it is associated with the olfactory threshold in healthy individuals. Aim of this study was to evaluate: 1) the presence of a relationship between the threshold olfactory performance of healthy subjects and the intensity with which they perceive the smelled odorants, and 2) the effect of the rs2590498 polymorphism of the OBPIIa gene on perceived intensity. We found a positive correlation between threshold olfactory and perceived intensity, and that AA homozygous subjects reported a perceived intensity higher than heterozygous and GG homozygous subjects. By showing a positive effect of the rs2590498 polymorphism of the hOBPIIa gene on the intensity perceived, these results suggest that it allows a larger number of molecules in an odorous mixture to reach the olfactory receptors

    SGUARDI OLTRE IL PONTE CITTA’ COSTIERE DI SICILIA E CALABRIA TRA WATERFRONT NUOVE PORTUALITA’

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    For many years the South has been at the center of attention of the public opinion, the completion of the bridge over the Stretto di Messina, as a "resolution" passage of the connecting corridor between mainland Italy and the Sicily. That's the expression of a territorial vision of Europe based on building a network that is essential for economic exchange and north-south transport would also open a brand new relationship between continental Europe and the countries of the North African area. That vision has largely overshadowed the dynamics of the southern coastal city of our country; it’s actually proposing, on the one hand, a projected growth of settlements on the seas that surround it (Tyrrhenian, Adriatic and Ionian) to which they are very diverse forms of expression and waterfront uses of multiform coastline, on the other, a system of landing places for a substantial internal mobility (for goods and people that do not underestimate the contribution from tourism-related water) in the Mediterranean bacin. The changes related to these new forms of urban growth would change the structure of many cities in the South, Mediterranean recover ancient paths of memory, creating new destinations: they appear involved, the traditional settlement patterns in the South, the same system of connections of short and medium distance as well as assumptions that bind to the construction of local platforms and logistics. In fact, in the "long waiting" of the bridge, there are certain situations that are heavily penalizing the South in terms of production and the same quality of life of the people, but we are also witnessing the growth of short-term initiatives aimed at reducing inconveniences and create new forms of relationships. Some emerging questions. Is rising up the possibility of a different relationship with the sea that make the Eurocentric vision less effective? Are there determining alternative uses of coastal areas? Do we highlight new conveniences for transport solutions that bring shadows radicals assumed to origin? It is considered advisable the "cultural review”, before operating the assumptions above and at least the same should be the subject of critical attention. The changes related to these new forms of urban growth would change the structure of many cities in the South, Mediterranean recover ancient paths of memory, creating new destinations: they appear involved, the traditional settlement patterns in the South, the same system of connections of short and medium distance as well as assumptions that bind to the construction of local platforms and logistics. The contribution will develop for the Biennial of Towns and Town Planners in Europe focuses on the changes that are driving in the cities of the South (and especially its southern parts) in particular is to highlight the connection not yet sufficient depth between the vision-type transport terms "a unique system of relationships and the European contribution, to some extent but still innovative alternative, which flows to the reorganization of transport from urban and territorial policies, more often an expression of local needs and not properly coordinated, but nevertheless substantial, for somewhat irreversible

    METHANATION OF CARBON DIOXIDE

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    Abstract This paper describes the CO 2 conversion to methane by reduction with hydrogen on a Ni catalyst. The catalyst has been characterized in terms of number of surface sites. The effect of H 2 S poisoning on catalytic activity has been evaluated too

    Gustatory Sensitivity and Food Acceptance in Two Phylogenetically Closely Related Papilionid Species: Papilio hospiton and Papilio machaon.

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    In herbivorous insects, food selection depends on sensitivity to specific chemical stimuli from host-plants as well as to secondary metabolites (bitter) and to sugars (phagostimulatory). Bitter compounds are noxious, unpalatable or both and evoke an aversive feeding response. Instead, sugars and sugar alcohols play a critical role in determining and enhancing the palatability of foods. We assumed that peripheral taste sensitivity may be related to the width of the host selection. Our model consists of two closely phylogenetically related Papilionid species exhibiting a difference in host plant choice: Papilio hospiton and Papilio machaon. The spike activity of the lateral and medial maxillary styloconic taste sensilla was recorded following stimulation with several carbohydrates, nicotine and NaCl, with the aim of characterizing their gustatory receptor neurons and of comparing their response patterns in the light of their different acceptability in feeding behaviour. The results show that: a) each sensillum houses phagostimulant and phagodeterrent cells; b) the spike activity of the gustatory neurons in response to different taste stimuli is higher in P. hospiton than in P. machaon; c) sugar solutions inhibit the spike activity of the deterrent and salt cells, and the suppression is higher in P. machaon than in P. hospiton. In conclusion, we propose that the different balance between the phagostimulant and phagodeterrent inputs from GRNs of maxillary sensilla may contribute in determining the difference in food choice and host range

    PRELIMINARY DATA ON FUMONISINS PRESENCE IN PIG LIVER

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    Mycotoxins are heterogeneous chemical compounds characterized by a low molecular weight and synthesized by the secondary metabolism of different molds. Fumonisins are water-soluble mycotoxins produced by Fusarium species spoiling corn and derived products. These mycotoxins can enter the food chain also through the consumption of meat of exposed animals. Fumonisins and their metabolites have been associated with several animal and human diseases. They are suspected risk factors for esophageal and liver cancers, neural tube defects and cardiovascular problems. Improved methods are needed to accurately assess fumonisin concentrations in food from vegetable and animal origin to prevent acute and chronic human exposure. The aim of the present work was to develop a sensitive and selective method for quantification and unambiguous identification of fumonisin B1 (FB1), fumonisin B2 (FB2) and their complete hydrolyzed products (HFB1 and HFB2), in order to determine their presence in pig liver. Furthermore, the developed method was applied, in order to test its efficacy, on liver samples of weaned piglets fed a diet in compliance with the FB1 and FB2 contamination limits set by EU. All the samples showed the presence of at least one of the analytes. In particular FB1 was found in 5 out of 7 samples and the average level of contamination found was 28 ppb

    Optical properties of bulk high-entropy diborides for solar energy applications

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    So far, the studies regarding the innovative High-Entropy Borides (HEBs), which belong to the more general class of Ultra-high temperature ceramics (UHTCs), have been entirely confined to their fabrication or characterization from the microstructural, mechanical and oxidation resistance viewpoints. In this work, the optical properties of two members of HEBs, i.e. (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2 and (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2, are evaluated for the first time to assess their possible utilization in the thermal solar energy field. The bulk samples (96.5 % and 97.4 % dense, respectively) are obtained as single-phase products by Spark Plasma Sintering (1950 °C/20 min/20 MPa) starting from powders previously synthesized by Self-propagating High-temperature Synthesis (SHS). The optical characterization, whose results are discussed by comparing HEBs to the individual borides, shows that they are characterized by intrinsic spectral selectivity and low thermal emittance, resulting therefore interesting for high-temperature solar absorbers applications
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