906 research outputs found

    First Occurrence of Willhendersonite in the Lessini Mounts, Northern Italy

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    none2noWillhendersonite is a rare zeolite, with very few occurrences reported globally (Terni Province, Italy; the Eifel Region, Germany; Styria, Austria). Moreover, the data available from these sites are very limited and do not allow a detailed picture of this zeolite’s mineralogical and chemical characteristics. In this work, a new willhendersonite occurrence is reported from the Tertiary volcanic rocks of the Lessini Mounts, northern Italy. Morphology, mineralogy and chemical composition of selected crystals were studied by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray Diffraction (XRD), and electron probe microanalyser (EPMA). Willhendersonite occurs within basanitic rocks as isolated, colorless, transparent crystals with prismatic to flattened morphologies. Individual crystals often grow together to form small elongated clusters and trellis-like aggregates. The diffraction pattern exhibits 33 well-resolved diffraction peaks, all of which can be indexed to a triclinic cell with unit cell parameters a = 9.239(2) Å; b = 9.221(2) Å; and c = 9.496(2) Å, α = 92.324(2)◦, β = 92.677(2)◦, γ = 89.992◦ (Space Group P1). The chemical data point to significant variability from Ca-rich willhendersonite (K0.23Na0.03 )Σ=0,26Ca1.24 (Si3.06Al3,00Fe3+0.01)Σ=6,07 O12·5H2O) to Ca-K terms (K0.94Na0.01)Σ=0,95Ca0.99 (Si3.07Al2.93Fe3+0.00)Σ=6,00O12·5H2O). Willhendersonite from the Lessini Mounts highlights the existence of an isomorphous series between the Ca-pure crystals and Ca-K compositions, possibly extended up to a potassic end-member.openMattioli, Michele; Cenni, MarcoMattioli, Michele; Cenni, Marc

    Proline affects the size of the root meristematic zone in Arabidopsis

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    We reported previously that root elongation in Arabidopsis is promoted by exogenous proline, raising the possibility that this amino acid may modulate root growth. To evaluate this hypothesis we used a combination of genetic, pharmacological and molecular analyses, and showed that proline specifically affects root growth by modulating the size of the root meristem. The effects of proline on meristem size are parallel to, and independent from, hormonal pathways, and do not involve the expression of genes controlling cell differentiation at the transition zone. On the contrary, proline appears to control cell division in early stages of postembryonic root development, as shown by the expression of the G2/M-specific CYCLINB1;1 (CYCB1;1) gene. The overall data suggest that proline can modulate the size of root meristematic zone in Arabidopsis likely controlling cell division and, in turn, the ratio between cell division and cell differentiation

    SFADI: the Speckle-Free Angular Differential Imaging method

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    We present a new processing technique aimed at significantly improving the angular differential imaging method (ADI) in the context of high-contrast imaging of faint objects nearby bright stars in observations obtained with extreme adaptive optics (EXAO) systems. This technique, named "SFADI" for "Speckle-Free ADI", allows to improve the achievable contrast by means of speckles identification and suppression. This is possible in very high cadence data, which freeze the atmospheric evolution. Here we present simulations in which synthetic planets are injected into a real millisecond frame rate sequence, acquired at the LBT telescope at visible wavelength, and show that this technique can deliver low and uniform background, allowing unambiguous detection of 10510^{-5} contrast planets, from 100100 to 300300 mas separations, under poor and highly variable seeing conditions (0.80.8 to 1.51.5 arcsec FWHM) and in only 2020 min of acquisition. A comparison with a standard ADI approach shows that the contrast limit is improved by a factor of 55. We extensively discuss the SFADI dependence on the various parameters like speckle identification threshold, frame integration time, and number of frames, as well as its ability to provide high-contrast imaging for extended sources, and also to work with fast acquisitions.Comment: Accepted for publication in Ap

    Do Board Games Make People Smarter? Two Initial Exploratory Studies

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    In recent years, the authors have witnessed the rebirth of board games. This contribution aims to investigate the educational potential of non-random board games in two ways: the comparison of performances of “expert adult players” and “adult non-players” through a correlation study (n=45) and the comparison between the results achieved by a group of children after 26 hours of game training (n=10) and those of a control group that carried out traditional educational activities (n=10) by using a nonrandomized control group pretest-posttest. Specifically, the findings relating to fluid intelligence, analytical and converging cognitive processes and creativity were compared. The results suggest that non-random board games can be an important stimulus for the cognitive functions, with a particular focus on the creative side, and therefore have an important educational function

    Proline synthesis in developing microspores is required for pollen development and fertility

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    Background: In many plants, the amino acid proline is strongly accumulated in pollen and disruption of proline synthesis caused abortion of microspore development in Arabidopsis. So far, it was unclear whether local biosynthesis or transport of proline determines the success of fertile pollen development. Results: We analyzed the expression pattern of the proline biosynthetic genes PYRROLINE-5-CARBOXYLATE SYNTHETASE 1 & 2 (P5CS1 & 2) in Arabidopsis anthers and both isoforms were strongly expressed in developing microspores and pollen grains but only inconsistently in surrounding sporophytic tissues. We introduced in a p5cs1/p5cs1 p5cs2/P5CS2 mutant background an additional copy of P5CS2 under the control of the Cauliflower Mosaic Virus (CaMV) 35S promoter, the tapetum-specific LIPID TRANSFER PROTEIN 12 (Ltp12) promoter or the pollen-specific At5g17340 promoter to determine in which site proline biosynthesis can restore the fertility of proline-deficient microspores. The specificity of these promoters was confirmed by β-glucuronidase (GUS) analysis, and by direct proline measurement in pollen grains and stage-9/10 anthers. Expression of P5CS2 under control of the At5g17340 promoter fully rescued proline content and normal morphology and fertility of mutant pollen. In contrast, expression of P5CS2 driven by either the Ltp12 or CaMV35S promoter caused only partial restoration of pollen development with little effect on pollen fertility. Conclusions: Overall, our results indicate that proline transport is not able to fulfill the demand of the cells of the male germ line. Pollen development and fertility depend on local proline biosynthesis during late stages of microspore development and in mature pollen grains

    Endothelial Function in Pre-diabetes, Diabetes and Diabetic Cardiomyopathy: A Review

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    Diabetes mellitus worsens cardiovascular risk profile of affected individuals. Its worldwide increasing prevalence and its negative influences on vascular walls morphology and function are able to induce the expression of several morbidities which worsen the clinical conditions of the patients getting them running towards a reduced survival curve. Although overt diabetes increases the mortality rate of individuals due to its pathogenesis, poor information are in literature about the role of pre-diabetes and family history of diabetes mellitus in the outcome of general population. This emphasizes the importance of early detection of vascular impairment in subjects at risk of developing diabetes. The identification of early stages of atherosclerotic diseases in diabetic persons is a fundamental step in the risk stratification protocols followed-up by physicians in order to have a complete overview about the clinical status of such individuals. Common carotid intima-media thickness, flow-mediated vasodilatation, pulse wave velocity are instrumental tools able to detect the early impairment in cardiovascular system and stratify cardiovascular risk of individuals. The aim of this review is to get a general perspective on the complex relationship between cardiovascular diseases onset, pre-diabetes and family history of diabetes. Furthermore, it points out the influence of diabetes on heart function till the expression of the so-called diabetic cardiomyopathy

    Trophic overlap between wolves and free-ranging wolf × dog hybrids in the Apennine Mountains, Italy

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    Hybridization between wolves (Canis lupus) and domestic dogs (Canis familiaris) can represent a threat to wild populations via genetic introgression and ecological competition. Therefore understanding the ecological role of hybrids may be crucial for developing appropriate conservation strategies. The Italian wolf population has a peculiar genetic composition due to a long-lasting geographic isolation. Nowadays, however, its genetic integrity is threatened by the spread of canine genes as a result of the hybridization with stray dogs in the wild. The aim of the present study was to gain insights into the ecological role of free-ranging wolf–dog hybrids by investigating their winter food habits in comparison with wolves in a mountain area of Central Italy. Levels of genetic introgression from the dogs were assessed in two adjacent areas occupied by up to five different packs by analyzing non-invasive samples and carcasses collected therein with a set of uniparental and bi-parental molecular markers. The obtained results enabled us to classify the two areas as 'hybrid' and 'wolf' areas based on their level of genetic introgression. Trophic niche and similarity/dissimilarity analyses did not detect significant difference in the diet between the two areas: in both of them, wild boar was the main prey, followed by roe deer. Furthermore, the same age/body mass classes of the two ungulates were selected by wolves and hybrids. Our findings confirmed wolf–dog hybrids as potential competitors for wolves. Further studies on other aspects of their biology and ecology are recommended in order to better estimate the impact of hybridization on natural wolf populations

    Un’esperienza di ricerca-formazione basata sulle competenze, nell’Istituto Comprensivo Melanzio-Parini di Castel Ritaldi

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    In recent years, the world of education has found itself facing a series of changes to meet the increasingly pressing needs of the world in which we live. From the methodological point of view, a series of innovative didactics have been developed, detached from the frontal lesson and from a transmitting idea of knowledge, favouring an active didactics where the student is at the centre of the learning process. In this article we present the results of a research-training aimed at verifying the effects of active and competencebased didactics in two classes (second and fifth) of primary school. To this end, the participating subjects were subjected, ex ante and ex post, to tests that verify their cognitive functioning, but also their approach and motivation to study. The results show an increase in the above mentioned dimensions for the experimental groups, compared to peer control groups, suggesting that these didactic interventions may have both a direct effect on the subjects’ learning, but also an empowerment effect of psychological and neuropsychological transversal dimensions.Negli ultimi anni il mondo della didattica, si è trovato ad affrontare una serie di cambiamenti per rispondere ai bisogni sempre più cogenti del mondo in cui viviamo. Dal punto di vista metodologico si sono sviluppate una serie di didattiche innovative che si distaccano dalla lezione frontale e da un’idea trasmissiva del sapere, privilegiando una didattica attiva dove l’alunno è al centro del processo di apprendimento. In questo articolo vengono presentati i risultati di una ricerca formazione tesa a verificare gli effetti di didattiche attive e per competenze in due classi (seconda e quinta) di scuola primaria. A tal fine i soggetti partecipanti sono stati sottoposti, ex ante ed ex post, alla somministrazione di test che verificano il funzionamento cognitivo, ma anche il loro approccio e la motivazione allo studio di cui sono portatori. I risultati mostrano un incremento delle dimensioni sopra citate per i gruppi sperimentali, rispetto a gruppi di controllo di pari, suggerendo che tali interventi didattici possano avere sia un effetto diretto sugli apprendimenti dei soggetti, ma anche un effetto di empowerment di dimensioni psicologiche e neuropsicologiche trasversali
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