10,219 research outputs found

    Drying kinetics and physico-chemical quality of mango slices

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    Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumerā€™s sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative process and extending the shelf-life. This study investigates the effect of dehydration at different temperatures (50, 60 and 70Ā°C) on drying kinetics and volatile compounds of two cultivars (Keitt and Osteen) of mango fruits cultivated in Sicily. Significant losses of volatile constituents of fresh mango occurred at higher temperature, especially for the Osteen cultivar. A diffusion model including the effect of shrinkage is also proposed, which may be used to describe drying behaviour of fruits and to define the optimal drying conditions.. Experimental data of the moisture ratio during drying were well predicted by the model

    A translation method for Belnap logic

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    In this report we present a translation of Belnap's four-valued logic into classical first-order logic. Soundness and completeness of the translation approach with respect to Belnap's notion of entailment are proved. Examples derivations are also given. These results provide the basis for developing a belief revision approach for Belnap's logic in terms of standard AGM belief revision operators for classical logic

    The perception of instability and legitimacy of status differences enhances the infrahumanization bias among high status groups

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    Previous research within the social identity framework has shown that perceptions of legitimacy and stability of status differences interactively determine cognitive, emotional, and behavioural responses to intergroup contexts. Whether such perceptions affect subtle forms of prejudice, namely infrahumanisation, is unknown. We examined if the perceptions regarding high status stability and legitimacy are associated to the infrahumanisation bias. We hypothesized that participants perceiving status differences as unstable and legitimate would report higher levels of infrahumanization than those who perceive status differences as stable and/or illegitimate. Participants (N = 439 Italian students enrolled in psychology courses) completed a structured paper-and-pencil questionnaire. We found that participants tended to attribute more negative secondary emotions to their ingroup (Italians) than to the outgroup (immigrants from Africa), indicating the presence of an infrahumanization bias. The results of a moderated regression aimed at predicting infrahumanization showed that high-status group members who perceived status differences as legitimate and unstable reported higher levels of infrahumanization than their counterparts did. The results attest the important and independent role of the perceptions related to the status for the debate on intergroup relations

    Stable non-BPS states in string theory: a pedagogical review

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    We present a pedagogical review of the stable non-BPS states in string theory which have recently attracted some attention in the literature. In particular, following the analysis of A. Sen, we discuss in detail the case of the stable non-BPS D-particle of Type I theory whose existence is predicted (and required) by the heterotic/Type I duality. We show that this D-particle originates from an unstable bound state formed by a D1/anti-D1 pair of Type IIB in which the tachyon field acquires a solitonic kink configuration. The mechanism of tachyon condensation is discussed first at a qualitative level and then with an exact conformal field theory analysis.Comment: 58 pages, 1 figure; minor correction

    Decay Modes of Intersecting Fluxbranes

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    Just as the single fluxbrane is quantum mechanically unstable to the nucleation of a locally charged spherical brane, so intersecting fluxbranes are unstable to various decay modes. Each individual element of the intersection can decay via the nucleation of a spherical brane, but uncharged spheres can also be nucleated in the region of intersection. For special values of the fluxes, however, intersecting fluxbranes are supersymmetric, and so are expected to be stable. We explicitly consider the instanton describing the decay modes of the two--element intersection (an F5-brane in the string theory context), and show that in dimensions greater than four the action for the decay mode of the supersymmetric intersection diverges. This observation allows us to show that stable intersecting fluxbranes should also exist in type 0A string theory.Comment: 19 pages, 6 figures. References adde

    Surgical treatment of sporadic vestibular schwannoma in a series of 1006 patients. Trattamento chirurgico degli schwannomi vestibolari: risultati su una serie di 1006 pazienti

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    La gestione dello schwannoma vestibolare (SV) sporadico si ĆØ gradualmente evoluta negli ultimi decenni. Lo scopo di questo studio ĆØ di analizzare lā€™evoluzione negli esiti chirurgici dellā€™exeresi di queste lesioni, realizzata da un team neurotologico tra il 1990 e il 2006, attraverso differenti approcci. ƈ stata eseguita una revisione retrospettica monocentrica dei dati clinici di 1006 pazienti. Al fine di valutare eventuali modifiche e progressi, il periodo di 17 anni ĆØ stato diviso in tre periodi, ciascuno comprendente rispettivamente 268 SV (1990- 1996), 299 SV (1997-2001), e 439 SV (2002-2006). Il follow-up medio ĆØ stato di 5,9 Ā± 2,4 anni. Complessivamente lā€™asportazione totale ĆØ stata ottenuta nel 99,4% dei casi. Il tasso di mortalitĆ  ĆØ stato dello 0,3%, la meningite e la perdita di liquido cefalo rachidiano (LCR) sono stati osservati nel 1,2% e il 9% dei casi, rispettivamente. La frequenza della perdita di LCR ĆØ diminuita dal 11,6% al 7,1% tra il primo e dellā€™ultimo periodo (p < 0,01) e la revisione chirurgica dal 3,4% al 0,9% (p < 0,05). Il nervo facciale ĆØ stato anatomicamente conservato nel 97,7% dei casi. Ad un anno, una buona funzione del nervo facciale ĆØ stata osservata nel 85,1% dei pazienti (I e II grado HouseBrackmann), con una variazione tra il primo e lā€™ultimo periodo che andava dal 78,4% al 87,6% (p < 0,05). Ad un anno post-operatorio la conservazione dellā€™udito ĆØ stata ottenuta nel 61,6% dei pazienti, passando dal 50,9% del primo periodo, al 69,0% del periodo piĆŗ recente (p < 0,05) (classe A + B + C dalla classificazione AAO-HNS). Lā€™udito utile (classe A + B) ĆØ stato conservato nel 33,5% dei casi complessivamente, con percentuali comprese tra il 21,8% e 42% nel primo e nellā€™ultimo periodo rispettivamente (p < 0,01). Gli esiti chirurgici dellā€™asportazion dello schwannoma vestibolare sporadico sono migliorati negli anni per quanto riguarda i risultati funzionali del nervo facciale, la conservazione dellā€™udito, le perdite di liquido cefalorachidiano, principalmente grazie allā€™esperienza del team neurotologico. I risultati funzionali dopo la rimozione microchirurgica completa SV di grandi dimensioni dipendono dallā€™ esperienza maturata sulle lesioni di piccole dimensioniThe management of sporadic vestibular schwannoma (VS) has evolved in the last decades. The aim of this study was to analyse the evolution in surgical outcomes of VSs operated by a neurotological team between 1990 and 2006 by different approaches. A monocentric retrospective review of medical charts of 1006 patients was performed. In order to assess eventual changes and progress, the 17-years period was divided in three periods, each one comprehending 268 VS (1990-1996), 299 VS (1997-2001), and 439 VS (2002-2006). Mean follow-up was 5.9 Ā± 2.4 years. Overall, complete VS removal was achieved in 99.4% of cases. Mortality rate was 0.3%, meningitis and CSF leaks were observed in 1.2 % and 9 % of the cases, respectively. CSF leakage decreased from 11.6% to 7.1% between the first and last period (p < 0.01) as well as revision surgery from 3.4 % to 0.9 % (p < 0.05). Facial nerve was anatomically preserved in 97.7% of cases. At one year, a good facial nerve function was observed in 85.1% of patients (grade I and II of House-Brackmann grading scale), which ranged between the first and last period from 78.4% to 87.6% (p <0.05). At one year, hearing preservation was obtained in 61.6% of patients, which increased from the first period to the last one from 50.9% to 69.0% (p < 0.05) (class A+B+C from the AAO-HNS classification). Useful hearing (class A+B) was observed in 33.5% of cases overall, with 21.8% and 42% in the first and last period, respectively (p < 0.01). Surgical outcomes of sporadic vestibular schwannoma have improved concerning facial nerve function outcomes, hearing preservation and cerebrospinal fluid (CSF) leaks, mainly due to the neuro-otological team's experience. Functional results after complete microsurgical removal of large VS depend on experience gained on small VS removal

    Genetic variants of Y chromosome are associated with a protective lipid profile in black men

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    Objectiveā€” Gender and ethnicity modulate the phenotypic expression of cardiovascular risk factors. In particular, men are at higher risk of developing cardiovascular diseases compared to women, whereas black populations of African origin display reduced mortality from coronary heart disease (CHD) as compared to both whites and South Asians. Because the male-specific region (MSY) of the human Y chromosome is an obvious candidate for gender-related differences in the development of cardiovascular diseases, we aimed to identify genetic variants of MSY influencing cardiovascular risk profile in different ethnic groups. Methods and Resultsā€” We genotyped 4 polymorphisms of MSY (HindIIIĀ±, rs768983 of TBL1Y, rs3212292 of USP9Y, and rs9341273 of UTY genes) in 579 men of different ethnic groups (blacks, South Asians, and whites) from UK and in 301 whites in Italy. We found that the TBL1YA USP9YA haplotype, present only in blacks in whom it represents the most frequent allelic combinations (AA: n=125; all other combinations: n=45), was associated with lower levels of triglycerides (P=0.025) and higher levels of HDL-cholesterol (P=0.005) as compared to the other haplotypes. Conclusionā€” The TBL1YA USP9YA haplotype of the Y chromosome, present only in black people of African origin, attributes a favorable lipoprotein pattern, likely to contribute to their reduced susceptibility to coronary heart disease. The study evaluated the association of genetic variants of the male-specific region of the Y chromosome with cardiovascular risk factors in different ethnic groups. The most frequently observed haplotype in black people was associated with a favorable lipoprotein pattern, thus contributing to the lower rate of cardiovascular diseases in blacks

    Representation of tropical deep convection in atmospheric models - Part 1 : Meteorology and comparison with satellite observations

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    Published under Creative Commons Licence 3.0. Original article can be found at : http://www.atmospheric-chemistry-and-physics.net/ "The author's copyright for this publication is transferred to University of Hertfordshire".Fast convective transport in the tropics can efficiently redistribute water vapour and pollutants up to the upper troposphere. In this study we compare tropical convection characteristics for the year 2005 in a range of atmospheric models, including numerical weather prediction (NWP) models, chemistry transport models (CTMs), and chemistry-climate models (CCMs). The model runs have been performed within the framework of the SCOUT-O3 (Stratospheric-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere) project. The characteristics of tropical convection, such as seasonal cycle, land/sea contrast and vertical extent, are analysed using satellite observations as a benchmark for model simulations. The observational datasets used in this work comprise precipitation rates, outgoing longwave radiation, cloud-top pressure, and water vapour from a number of independent sources, including ERA-Interim analyses. Most models are generally able to reproduce the seasonal cycle and strength of precipitation for continental regions but show larger discrepancies with observations for the Maritime Continent region. The frequency distribution of high clouds from models and observations is calculated using highly temporally-resolved (up to 3-hourly) cloud top data. The percentage of clouds above 15 km varies significantly between the models. Vertical profiles of water vapour in the upper troposphere-lower stratosphere (UTLS) show large differences between the models which can only be partly attributed to temperature differences. If a convective plume reaches above the level of zero net radiative heating, which is estimated to be ~15 km in the tropics, the air detrained from it can be transported upwards by radiative heating into the lower stratosphere. In this context, we discuss the role of tropical convection as a precursor for the transport of short-lived species into the lower stratosphere.Peer reviewe

    Bibliometric Analysis of Scientific Production Related to Tick Control

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    Ticks are distributed all over the world and significantly affect human and animal health. Increasing public health concern with tick borne diseases requires the strategic control of ticks in animals that transmit diseases to humans. The aim of this article is to present a bibliometric analysis of the scientific production related to tick control, using bibliometrics as an instrument of analysis to measure scientific activity. To identify the studies , a search was made on four Scopus databases, Web of Science, Medline / Pubmed and Science Direct. Of 1764 publications, only 480 were analyzed after the exclusion of certain productions according to previously defined criteria. It was pointed out that the identified studies have great relevance for the control of ticks, considering that scientific publications are important markers of the activity of production and development of the field of knowledge
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