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Showing papers by "University of Udine published in 1992"


Journal ArticleDOI
TL;DR: In a recent survey of the subject of environmental economics, this paper pointed out that the primary environmental issues are now "very cold" as topics for analytical investigation, and "dead" as research problems.

224 citations


Journal ArticleDOI
TL;DR: The results suggest that Ca+ channel blockers and antioxidants, although inactive on oxidative stress-induced Ca2+ release from intracellular stores, prevent the increased influx apparently related to a membrane thiol oxidation.

175 citations


Journal ArticleDOI
TL;DR: Of the three proteases, only elastase is able to catalyze the stepwise cleavage of probactenecins into the corresponding mature peptides, which have the same mass, N-terminal sequence and antibiotic activity of authentic Bac5 and Bac7.
Abstract: Bac5 and Bac7, antibiotics of the bactenecin (proline/arginine-rich peptide) family, are stored as proforms in the large granules of bovine neutrophils [Zanetti, M., Litteri, L., Gennaro, R., Horstmann, H. and Romeo, D. (1990) J. Cell Biol. 111, 1363-1371]. These proforms have been purified to homogeneity from granule extracts by immunoaffinity and reverse-phase chromatography. While mature bactenecins efficiently kill Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium with minimal inhibitory concentrations of 6-12 micrograms/ml, proBac5 and proBac7 do not affect the growth of the same microorganisms, even at 500 micrograms/ml. Previous investigations have suggested that the conversion of probactenecins into mature antimicrobial peptides is catalyzed by a neutral serine protease stored in the azurophil granules. Purified proBac5 and proBac7 were thus treated with elastase, cathepsin G or proteinase 3, which constitute the pool of neutral serine proteases of the azurophils, and the reaction products were identified by Western blot analysis, mass spectrometry, and N-terminal sequence analysis. Of the three proteases, only elastase is able to catalyze the stepwise cleavage of probactenecins into the corresponding mature peptides, which have the same mass, N-terminal sequence and antibiotic activity of authentic Bac5 and Bac7. These results point to the importance of cooperation between azurophils and large granules in mounting a defense reaction.

148 citations


Journal ArticleDOI
TL;DR: It is suggested that neural structures fed by the left eye are better at processing and/or storing of visual information which allows recognition of individual conspecifics which is part of a wider tendency to respond to small changes in any of a variety of intrinsic stimulus properties.

141 citations


Journal ArticleDOI
TL;DR: These findings suggest the possibility that oxidative stress may be related to the development of diabetic complications and may lead to new therapeutic approaches for the prevention of complications by limiting the damage caused by non‐enzymatic glycosylation and oxidant stress.
Abstract: It is generally accepted that chronic hyperglycaemia is responsible for most of the long-term complications of diabetes. Several studies suggest that accelerated non-enzymatic glycosylation may be the underlying mechanism by which hyperglycaemia causes complications. More recently, glucose auto-oxidation has been linked to non-enzymatic glycosylation, and glycosylated proteins have been shown to be a source of free radicals. These findings suggest the possibility that oxidative stress may be related to the development of diabetic complications. Anti-oxidants such as vitamins C and E have recently been demonstrated to reduce protein glycosylation both in vivo and in vitro. In addition they also act as scavengers of free radicals generated by non-enzymatic glycosylation of protein. These findings may lead to new therapeutic approaches for the prevention of complications by limiting the damage caused by non-enzymatic glycosylation and oxidant stress. Such therapies may also be useful in complementing existing treatment in those with the long-term complications of diabetes.

137 citations


Journal ArticleDOI
TL;DR: Therapy with erythropoietin induced a decrease in plasma histamine concentrations in both groups of patients with uremia, and recurrences of pruritus after the discontinuation of erythrooiet in were accompanied by increases in plasma Histamine concentrations.
Abstract: Background. The pathophysiologic aspects of pruritus in patients with chronic renal insufficiency are poorly understood, and there is no universally effective treatment. The improvement of pruritus in several patients receiving erythropoietin therapy raised the possibility that erythropoietin affects uremic pruritus directly. Methods. We undertook a 10-week placebo-controlled, double-blind, crossover study in a group of patients receiving hemodialysis who had severe pruritus, to investigate the effects of recombinant human erythropoietin on their pruritus and plasma histamine levels. Twenty patients with uremia, of whom 10 had severe pruritus and 10 did not, received erythropoietin (36 units per kilogram of body weight three times weekly) and placebo in random order, each for five weeks. The severity of pruritus was scored weekly, and plasma histamine levels were measured at the beginning and end of each five-week period. Results. Eight of the 10 patients with pruritus had marked reductions in th...

136 citations


Journal ArticleDOI
TL;DR: In this paper, the synthesis of nanometer-sized α-Al2O3−M composites (nanocomposites) is described for M = Fe, V, Cr, Mn, Co, Ni, Cu, Zn, Nb, Mo, W, Si, and Fe alloys.
Abstract: The synthesis of nanometer-sized α-Al2O3−M composites (nanocomposites) is described for M = Fe, V, Cr, Mn, Co, Ni, Cu, Zn, Nb, Mo, W, Si, and Fe alloys. The synthesis is performed by solid-state reduction reaction which occurs during room-temperature ball-milling of mixtures of a metal oxide (MxOy) and aluminum (Al2y/3). A complete reduction is reached for milling times of ≅ 1.5 h in a planetary mill. The crystallite sizes of alumina and metal obatined, for powders processed in a vibratory mill, are in general about 10 nm.

132 citations


Journal ArticleDOI
TL;DR: The chain-breaking antioxidant capacity of Mn(II) seems to be related to the rapid quenching of peroxyl radicals according to the reaction R-OO, considering the different reduction potentials of the examined cations.

124 citations


Journal ArticleDOI
TL;DR: Data show that high glucose levels may delay endothelial cells replication time through the generation of free radicals, suggesting a possible pathophysiological linkage between the high levels of glucose and the development of microvascular complications of diabetes, possibly suggesting a new therapeutic approach to prevent such complications.
Abstract: Exposure to hyperglycemia slows the rate of proliferation of cultured human endothelial cells. Recently, it has been reported that glucose may autoxidize generating free radicals which have been hypothesized to delay cell replication time. To test whether oxidative stress has an effect on delaying cell replication time in hyperglycemic conditions, human endothelial cells cultured from umbilical veins were incubated in 5 or 20 mM glucose, either alone or in the presence of one of three different antioxidants: superoxide dismutase (SOD), catalase and glutathione (GSH). Cells grown in medium with 5 mM glucose, with or without antioxidants, yielded similar population doubling times and cell cycle phase distributions. Significantly lower growth parameters were observed in cells grown in medium with 20 mM glucose, without antioxidants. The presence of the antioxidant reverted them to almost normal growth. These data show that high glucose levels may delay endothelial cells replication time through the generation of free radicals, suggesting a possible pathophysiological linkage between the high levels of glucose and the development of microvascular complications of diabetes, possibly suggesting a new therapeutic approach to prevent such complications.

122 citations


Journal ArticleDOI
TL;DR: In a multivariate analysis of higher alcohol production two main groupings were formed at 86%S, corresponding to the taxa H. guilliermondii and K. apiculata.
Abstract: P. ROMANO, G. SUZZI, G. COMI AND R. ZIRONI. 1992. Ninety-six strains of apiculate wine yeasts were investigated for their ability to produce higher alcohols and acetic acid in synthetic medium. Less isoamyl alcohol and more n-propanol and isobutanol were formed by Hanseniaspora guilliermondii than by Kloeckera apiculata. The latter produced twice as much acetic acid as H. guilliermondii. The production of higher alcohols and acetic acid was found to be a characteristic of individual strains and was statistically significant. In a multivariate analysis of higher alcohol production two main groupings were formed at 86%S, corresponding to the taxa H. guilliermondii and K. apiculata. Strains that produced low amounts (50 mg/1) of acetic acid, comparable with that of Saccharomyces cerevisiae, were found in both species of apiculate yeasts.

121 citations


Journal ArticleDOI
TL;DR: The Edinburgh Logical Framework is a logic-independent tool which, given a specification for a logical system, synthesizes a proof editor and checker for that system and to what extent it is successful is discussed.
Abstract: Much research has been devoted in building computer systems for checking proofs or for developing interactively correct proofs in specific logical systems. However, implementing a proof environment for a specific logical system is both complex and time-consuming, this-together with the proliferation of logics-suggests that a uniform and reliable alternative is desirable. One such alternative is the Edinburgh Logical Framework (LF), developed in the late eighties at the LFCS (Laboratory for Foundations of Computer Science). The LF is a logic-independent tool which, given a specification for a logical system, synthesizes a proof editor and checker for that system. Its specification language is based on a general theory of logics, which enables one to capture uniformities and idiosyncrasies of a large class of logics without sacrificing generality for tractability. Peculiarities (such as side conditions on rule application, variable occurrence or formula formation) are expressed at the level of the specification. In this paper we are going to provide a broad illustration of its applicability and discuss to what extent it is successful. The analysis (of the formal presentation) of a system carried out through encoding often illuminates the system itself. This paper will also deal with this phenomenon.

Journal ArticleDOI
TL;DR: The authors prove an Approximation Theorem, which holds in all topological models, thatTopological models are not complete w.r.t. λ-calculus.

Journal ArticleDOI
TL;DR: A high-performance liquid chromatography method is described for the simultaneous determination of the biogenic amines tryptamine, 2-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine in cheese.

Journal ArticleDOI
TL;DR: It is argued that gender effects in social discrimination can be accounted for in terms of stronger social attachment in females and aggressive responses in males.
Abstract: Social discrimination in male and female domestic chicks (Gallus gallus) was investigated by using (a) latencies of approach response, (b) simultaneous free choice, and (c) intersubject aggressive-pecking tests. In approach-response tests, females showed shorter latencies when tested with cagemates than when tested with strangers, whereas males showed shorter latencies when tested with strangers than when tested with cagemates. In simultaneous-choice tests, females spent more time near a cagemate, whereas males spent more time near a strange chick. In aggressive-pecking tests, both sexes pecked more at strangers than at cagemates; aggressive pecking at strangers, however, was higher in males than in females. It is argued that gender effects in social discrimination can be accounted for in terms of stronger social attachment in females and aggressive responses in males.


Journal ArticleDOI
TL;DR: The coincidence between the increase in the reinfestation rate and the scarcity of nectar flow and the massive importation of mites, observed especially in September and October, suggest that rein festation was mainly caused by robbing of infested colonies (mostly feral swarms) by the bees of treated colonies.
Abstract: The sources of reinfestation of a treated apiary byVarroa jacobsoni Oud. were studied in Friuli (North-Eastern Italy), in an area with a high density of colonies. Ten colonies, initiallyVarroa-free, were treated with Apistan or Bayvarol strips and mites killed by these treatments were counted twice a week for 1 year. Five hives were provided with “drone excluders”, to avoid the entrance of drones from other apiaries. Nectar and honeydew flow were monitored. The reinfestation rate was low during spring, varied between 1.6–13.7 mites/day/colony during June, July and first week of August, and rose impressively during September and October (up to a mean of 75.6 mites/day/colony); it was relatively high when nectar flow was scarce. The presence of drone excluders did not help to limit the number of mites imported: drones did not seem to be the main cause of reinfestation. The coincidence between the increase in the reinfestation rate and the scarcity of nectar flow and the massive importation of mites, observed especially in September and October, suggest that reinfestation was mainly caused by robbing of infested colonies (mostly feral swarms) by the bees of treated colonies.

Journal ArticleDOI
TL;DR: A correlation of spectral simplification with the known tertiary structure establishes the feasibility of new strategies for topological mapping of surface and buried protons of the protein and applies to the elucidation of protein structure and to the study of dynamical processes.

Journal ArticleDOI
TL;DR: In this paper, a conceptual model for operations that can be utilized in identifying the most significant opportunities and decisions in order to obtain competitive advantages in global industries is proposed, considering the following elements: competitive advantages, the performance of the operating system (as sources of competitive advantage) and the four phases of the so-called operation value chain: design, purchasing, production and distribution.
Abstract: Suggests a conceptual model for operations that can be utilized in identifying the most significant opportunities and decisions in order to obtain competitive advantages in global industries. The model considers the following elements: competitive advantages, the performance of the operating system (as sources of competitive advantage) and the four phases of the so‐called operation value chain: design, purchasing, production and distribution. The study of the implications on production strategy deriving from globalization is carried out using three groups of strategic decision categories: organization and management, management systems, technologies. The crossing of the three groups of strategic decision categories and the four operations phases identifies a matrix with twelve areas of opportunities and decisions for realization of global‐type strategies. The proposed model makes it possible to identify the emergence of three paradigms in global industries regarding performance and behaviour of companies:...

Journal ArticleDOI
TL;DR: In this article, the existence of periodic solutions in a compact attractor of (R+)n for the Kolmogorov system x′i= xifi(t, x1, …, xn), i = l, l, n in the competitive case.
Abstract: We prove the existence of periodic solutions in a compact attractor of (R+)n for the Kolmogorov system x′i= xifi(t, x1, …, xn), i = l, …, n in the competitive case. Extension to differential delay equations are con- sidered too. Applications are given to Lotka-Volterra systems with periodic coefficients.

Journal ArticleDOI
TL;DR: The spin asymmetry of transversely-polarized protons was measured at Fermilab over a wide range of XF, with a value of 0.15±0.03 in the region 0.6
Abstract: The spin asymmetryAN for inclusive π0 production by 200-GeV transversely-polarized protons on a liquid hydrogen target has been measured at Fermilab over a wide range ofxF, with 0.5 0.3, the asymmetry rises with increasingxF and reaches a value ofAN=0.15±0.03 in the region 0.6

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the selectivity of iridium and ruthenium catalysts in unsaturated carbonyl compounds over groups 8 and 9 titania-supported metal catalysts.

Journal ArticleDOI
TL;DR: In this article, the authors compared the end products and the time courses of mineralization and humification during the theermophilic phase of two different composting processes used to transform residues from cotton carding.

Journal ArticleDOI
TL;DR: Ain d'obtenir des informations supplementaires sur les populations locales d'abeilles, nous avons fait une analyse morphometrique sur des abeilles prelevees dans le Frioul.
Abstract: Le Frioul dans le Nord-Est de l'Italie est considere comme une zone d'hybridation entre Apis mellifera ligustica et Apis mellifera carnica, mais jusqu'a present une seule analyse morphometrique avait ete realisee sur des echantillons d'abeilles venant de cette region. Afin d'obtenir des informations supplementaires sur les populations locales d'abeilles, nous avons fait une analyse morphometrique sur des abeilles prelevees dans le Frioul. Des echantillons d'A m ligustica et d'A m carnica recoltes dans leurs propres regions de repartition ont egalement ete analyses

Journal ArticleDOI
TL;DR: It is shown that the formal system for binary decompositions of database relations applies successfully to binary decomPOSitions of probability distributions and graphs too.

Journal ArticleDOI
TL;DR: In this article, the effect of humic fraction on microsomal and tonoplast ion-stimulated ATPase activity was studied, and the main target of the humic molecules is the electrical membrane potential and suggest a possible way of interference of these naturally occurring substances with the biochemical mechanisms involved in plant mineral nutrition.
Abstract: The effect of a low molecular size (<5 KDa) humic fraction, essentially fulvic acids, on microsomal and tonoplast ion-stimulated ATPase activity was studied. After 20 min of pre-incubation with microsomal vesicles from oat roots, humic substances at organic C concentration of up to 0.5 μg cm-3 increased KCl-stimulated ATPase activity, while they inhibited enzyme activity at higher concentrations. Cl--stimulated ATPase activity of tightly sealed tonoplast-enriched vesicles was similarly affected by <5 KDa humic substances. This behaviour was not observed when gramicidin D was added to the assay medium. Proton transport by vesicles incubated up to 5 min with <5 KDa humic molecules was affected in a concentration-dependent manner, strongly resembling that observed for ATP hydrolysis, whereas it was severely reduced when the assay conditions were close to those used for measuring ATP hydrolysis (20 min pre-incubation of vesicles with humic substances). The transmembrane electrical potential was negatively affected, irrespective of the concentration of humic molecules. Furthermore, a 15-min pre-incubation strongly reduced the formation of a potential gradient. The size and concentrations of humic substances employed make an interaction with the vacuolar membrane of root cells plausible. The results show that the main target of humic molecules is the electrical membrane potential and suggest a possible way of interference of these naturally occurring substances with the biochemical mechanisms involved in plant mineral nutrition.

Journal ArticleDOI
TL;DR: Three strains of Saccharomyces cerevisiae have been adapted in vitro upon treatment with copper or cadmium and Catalase level remains almost unchanged in the conditions tested, showing a lack of correlation with growth rate and metal uptake.

Journal ArticleDOI
TL;DR: The reaction between the antitumor octahedral complex trans-RuCl2(DMSO)4 and d(GpG)4 leads to the formation of a stable compound characterized by a covalent bifunctional coordination of the bases to the metal center, indicating that such a way of interaction with DNA is not exclusive to Pt or to metals with square planar coordination geometries.
Abstract: The reaction between the antitumor octahedral complex trans-RuCl2(DMSO)4 and d(GpG) leads to the formation of a stable compound characterized by a covalent bifunctional coordination of the bases to the metal center The structure of the compound has been fully characterized by NMR and molecular modeling studies, showing the presence of two N7-coordinated guanine moieties in a head to head conformation, two dimethyl sulfoxide molecules, and one halogen atom in the coordination sphere of the ruthenium The glycosidic chi angles are essentially in the anti range, the sugar puckering of the 5'G is 3'-endo (100% N), whereas that of the 3'G is more flexible but mainly in 2'-endo conformation (85% S), the two bases are strongly destacked The compound shows structural features which are surprisingly similar to those exhibited by the corresponding cisplatin complex, indicating that such a way of interaction with DNA is not exclusive to Pt or to metals with square planar coordination geometries

Journal ArticleDOI
TL;DR: It seems that the low incidence of listeriosis from these products is related to the low concentration and virulence of L. monocytogenes present.
Abstract: Listeria monocytogenes was isolated and enumerated in Italian fresh ground beef, fresh pork meat and industrial sausages. All the samples contained less than 2000 L. monocytogenes/g of meat. The main serotype isolated was 1/2c (56.9%). Other serotypes isolated included 1/2a, 1/2b, 3c, 4b and 4c. A prevalence of less virulent serotypes over more virulent was thus noted. It seems that the low incidence of listeriosis from these products is related to the low concentration and virulence of L. monocytogenes present.

Journal ArticleDOI
P. Abreu1, Wolfgang Adam2, Tim Adye3, E. Agasi  +551 moreInstitutions (43)
TL;DR: In this paper, seven unambiguous events out of a sample of 270 000 Z0 decays, contain in the same jet a Ds meson and a muon at large transverse momentum relative to the jet axis.

Journal ArticleDOI
TL;DR: In this paper, room temperature reduction and exchange reactions of metal (M) sulphides are described, driven by ball mining powder mixtures of the sulphide and the reductant (R) or exchange compound (CaO).
Abstract: Solid state room temperature reduction and exchange reactions of metal (M) sulphides are described. Reactions are driven by ball mining powder mixtures of the sulphide and the reductant (R) or exchange compound (CaO). Reduction reactions show a complete reduction of the metal sulphide with formation of M-R sulphide nanocomposites. Exchange reactions with CaO show the formation of M oxide -CaS nanocomposites. Reactions having positive enthalpy or even positive free-energy changes in a wide temperature range are shown to occur. The effect of milling iron sulphide alone is also reported. Milling was performed for 24 h to assess the feasibility of the various reactions involved. X-ray diffraction and Mossbauer spectroscopy for iron-containing systems were used to characterize the powders before and after processing.