283 research outputs found

    Thermoanalytical characterization of several Antarctic meteorites

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    Thermodynamic data for several meteorites from Antarctica (5 achondrites, 2 chondrites, and 1 iron) were derived. The thermochemical response to heating in air was examined. The effects of oxidation processes can often be better identified by comparing the differential thermal analysis (DTA)-curves for heating in air with those obtained for heating in an oxidation-suppressed argon atmosphere. The thermoanalytical method can be helpful in determining the degree of weathering of meteoritic material

    Diversity and Distribution of the Inland Water Decapods of Sicily (Crustacea, Malacostraca)

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    The current knowledge of Sicilian inland water decapod malacostracans is scarce and an updated synopsis on species distribution is lacking. Therefore, we reviewed the checklist and recent distribution of Sicilian inland water decapods based on published and unpublished records and novel observations with the aim of providing an exhaustive repository, also to be used as a sound baseline for future surveys. Overall, five native decapod species occur in the study area, i.e., the atyid shrimp Atyaephyra desmarestii, the palaemonid shrimps Palaemon adspersus, P. antennarius, and P. elegans, and the freshwater crab Potamon fluviatile, and their current local distributions are described. In addition, three alien species were recorded: the common yabby Cherax destructor and the red swamp crayfish Procambarus clarkii, strictly linked to inland waters, and the Atlantic blue crab Callinectes sapidus, a mainly marine species that can also colonise the lower stretches of rivers and coastal brackish waters. The collected data suggest the existence of a partial segregation of native versus non-native species, with the latter currently confined to coastal water bodies and the lower stretches of rivers. Moreover, the exclusively freshwater caridean A. desmarestii and P. antennarius show a parapatric distribution in the study area, which may suggest the existence of mutual exclusion phenomena. The results obtained raise some concerns about the effects of alien species on the native biota, and dedicated monitoring and management strategies should be implemented in order to better understand and mitigate their impact

    Academic Resilience: A Retrospective Study of Adults With Learning Difficulties

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    This article reports qualitative analyses of two sets of retrospective interviews with adults with learning difficulties. The purpose of the study was to examine the high school experiences of these adults from a holistic perspective to understand possible factors that contributed to one group staying in school and the other group leaving school early. One set of interviews was conducted with adults who had returned to complete high school at an adult learning center (the late successful group). The second set of interviews was conducted with the early successful group, adults who had completed high school during adolescence. Interview questions focused on interests, friends, and general aspects of the high school experience. Analyses yielded three themes: intrapersonal support, interpersonal support, and institutional support. These data suggest that schools might act in a number of ways to counter the high rate of early leaving by adolescents with learning disabilities, including building strong teacher-student relationships, using students' interests to develop curricula and structured activities, and fostering a sense of purpose.Cet article expose deux analyses qualitatives de deux séries d'entrevues rétrospectives auprès d'adultes présentant des difficultés d'apprentissage. Le but de l'étude consistait à examiner, dans une perspective holistique, les expériences qu'avaient vécues ces adultes quand ils étaient au secondaire, pour ensuite déterminer si des facteurs avaient influencé le fait que certaines personnes étaient restées à l'école alors que d'autres avaient décroché. Une série d'entrevues a été effectuée auprès d'adultes qui avaient repris leurs études secondaires dans un institut d'apprentissage pour adultes (le groupe de diplômés tardifs). La deuxième série d'entrevues a eu lieu auprès d'adultes ayant terminé l'école secondaire alors qu'ils étaient adolescents dégroupe de diplômés précoces). Les questions d'entrevues portaient sur les intérêts, les amis et les aspects généraux de leur expérience à l'école secondaire. Trois thèmes sont ressortis des analyses: l'appui intrapersonnel, l'appui interpersonnel et l'appui institutionnel. Ces données donnent à penser que les écoles pourraient intervenir de diverses façons pour contrer le taux élevé de décrochage chez les adolescents ayant des difficultés d'apprentissage. Parmi ces stratégies notons la création de rapports solides entre les enseignants et les élèves, le développement de programmes d'études et d'activités structurées basés sur les intérêts des élèves et le fait de favoriser des buts bien précis

    Metabolic improvements following Roux-en-Y surgery assessed by solid meal test in subjects with short duration type 2 diabetes

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    BACKGROUND: Glucose homeostasis improves within days following Roux-en-Y gastric bypass (RYGB) surgery. The dynamic metabolic response to caloric intake following RYGB has been assessed using liquid mixed meal tolerance tests (MMTT). Few studies have evaluated the glycemic and hormonal response to a solid mixed meal in subjects with diabetes prior to, and within the first month following RYGB. METHODS: Seventeen women with type 2 diabetes of less than 5 years duration participated. Fasting measures of glucose homeostasis, lipids and gut hormones were obtained pre- and post-surgery. MMTT utilizing a solid 4 oz chocolate pudding performed pre-, 2 and 4 weeks post-surgery. Metabolic response to 4 and 2 oz MMTT assessed in five diabetic subjects not undergoing surgery. RESULTS: Significant reductions in fasting glucose and insulin at 3 days, and in fasting betatrophin, triglycerides and total cholesterol at 2 weeks post-surgery. Hepatic insulin clearance was greater at 3 days post-surgery. Subjects exhibited less hunger and greater feelings of fullness and satisfaction during the MMTT while consuming 52.9 ± 6.5% and 51.0 ± 6.5% of the meal at 2 and 4 weeks post-surgery respectively. At 2 weeks post-surgery, glucose and insulin response to MMTT were improved, with greater GLP-1 and PYY secretion. Improved response to solid MMTT not replicated by consumption of smaller pudding volume in diabetic non-surgical subjects. CONCLUSIONS: With a test meal of size and composition representative of the routine diet of post-RYGB subjects, improved glycemic and gut hormone responses occur which cannot be replicated by reducing the size of the MMTT in diabetic subjects not undergoing surgery

    New distributional data for the Mediterranean medicinal leech Hirudo verbana Carena, 1820 (Hirudinea, Hirudinidae) in Italy, with a note on its feeding on amphibians

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    Scarce data are currently available about the distribution of the Mediterranean medicinal leech Hirudo verbana in Italy, and most of the known occurrence localities are based on records collected in the nineteenth and the first half of the twentieth century, which were not confirmed in the last decades, mostly due to a lack of surveys. Accordingly, the available knowledge on the distribution of the species is far from being updated and representative, although a significant negative trend of H. verbana throughout the country is supposed. The lack of sound distribution data is a significant shortfall, which hinders the implementation of the monitoring of the species as required by the Article 17 of the “Habitats Directive” on the species of Union concern. To provide recent, validated distributional data for the Mediterranean medicinal leech in Italy to be used as baseline data for further surveys and monitoring, we present herein a set of unpublished observations collected in the last decades in peninsular Italy, Sicily, and Sardinia. Moreover, we report observation of H. verbana feeding on amphibians, a feeding habit to date poorly documented for the Mediterranean medicinal leech. Based on both published and novel data, H. verbana is characterised by a large but fragmented distribution in Italy. Therefore, dedicated monitoring programs and the collection of validated occasional observations are highly desirable to get a clearer picture of the real distribution of the species

    Ecosistemi di acque interne e di transizione

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    In questo contributo la vulnerabilità degli ecosistemi acquatici ai cambiamenti climatici è analizzata in relazione ai meccanismi di organizzazione e mantenimento della biodiversità e dei processi ecosistemici. Dai processi degli ecosistemi derivano funzioni che forniscono una serie di benefici o servizi per il genere umano (Daily et al., 2009). Tali servizi sono in larga misura dipendenti dalle componenti biologiche degli ecosistemi86. Negli ecosistemi acquatici i processi biogeochimici (ad es. denitrificazione batterica e assimilazione da parte della vegetazione acquatica), garantiscono l’abbattimento dei nutrienti, una funzione ecosistemica che produce il servizio di depurazione dell’acqua. Altri servizi sono la laminazione delle piene, la ricarica degli acquiferi, la regolazione del microclima locale, la produzione di risorse alimentari quali pesci, crostacei, ecc. (Jones, 2013). Le alterazioni degli ecosistemi, in particolare la perdita di specie e la diminuzione della biodiversità danneggiano questi servizi, con ricadute anche di tipo economico(si pensi, ad esempio, ai costi della depurazione dell’acqua destinata al consumo umano)
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