447 research outputs found

    La vita in una goccia d'acqua: spunti per un'azione didattico-educativa.

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    Il progetto \ue8 stato presentato dal Consiglio Direttivo della SIP (Societ\ue0 Itlaiana di Protistologia ONLUS). L\u2019obiettivo principale di questo progetto \ue8 quello di costituire ed organizzare un\u2019iniziativa didatticoformativapresso gli insegnanti di scienze della scuola secondaria di primo grado, come educatori della classe dei giovani in et\ue0 scolare, volta a sviluppare le cognizioni scientifico-applicative sull\u2019importanza dei microorganismi unicellulari eucariotici, comunemente definiti "protisti", in ambito sanitario e ambientale. Molto spesso dei protisti, i principali artefici del pi\uf9 grande salto evolutivo nella storia dei viventi, non esiste il bench\ue9 minimo accenno. La principale ragione di tale incompletezza sta nella non facile presentazione di tali organismi. I protisti, infatti, hanno dimensioni microscopiche e quindi non sono visibili ad occhio nudo. Eppure, questi organismi, oltre ad avere un elevata importanza evolutiva, sono indicatori di qualit\ue0 dell\u2019ambiente oltre ad essere di imponente interesse sanitario. I protisti di tipo parassitologico sono gli agenti infettanti di malattie molto gravi, quali la malaria, la toxoplasmosi e la leishmaniosi, tra le pi\uf9 note, e rivestono, oggi, grande importanza nei progetti d\u2019interesse prioritario per gli interventi istituzionali di sanit\ue0 pubblica in Italia e nel resto del mondo, ma di essi e delle loro infezioni ben poco sanno gli operatori e gli utenti della scuola secondaria dove, invece, il messaggio educazionale pu\uf2 essere molto efficiente anche in termini di prevenzione. Per tutto questo \ue8 molto importante promuovere la conoscenza di tale \u201cmondo sommerso\u201d nel quale esistono organismi sia da evitare in quanto patogeni (prevenzione primaria) che da promuovere in ambienti naturali (monitoraggio ambientale e controllo dell\u2019inquinamento). Il secondo obiettivo \ue8 quello di mettere al servizio di questa iniziativa le conoscenze scientifiche che vengono dalla ricerca, la pi\uf9 specializzata, come quella perseguita dai ricercatori che nel progetto svolgono le docenze. Contestualmente, il terzo obiettivo \ue8 quello di sopperire alla mancanza di informazioni sui protisti, rendendo evidente, attraverso l\u2019allestimento di una sala didattico-espositiva presso il Museo del Mare che ha sede nell\u2019Area Marina Protetta (AMP) Torre del Cerrano, l\u2019immagine di questo microcosmo, che svela i principali fenomeni che regolano la vita sulla Terra e che svolge un importante ruolo per la conservazione della biodiversit\ue0 sul nostro pianeta. Quest\u2019ultimo obiettivo \ue8 raggiunto anche dagli insegnanti e dai loro studenti, mettendo in uso le conoscenze ottenute nel corso del progetto, tramite l\u2019utilizzo della sala didattico-espositiva come un laboratorio di ricerca. In base a quanto sopra esposto possiamo dire che i risultati attesi da questo progetto sono: 1. Accrescimento delle cognizioni tecnico-scientifiche da parte degli insegnanti di scienze della scuola secondaria arruolati nel progetto nel settore della Protistologia, con particolare riguardo all\u2019importanza evolutiva e applicativa nel settore ambientale e sanitario dei protisti. 2. Ricaduta di queste cognizioni sugli studenti delle classi coinvolte, come risultato dell\u2019adempimento didattico dei suddetti insegnanti e rafforzamento delle stesse tramite l\u2019utilizzazione della sala didattico-espositiva come laboratorio applicativo di lavori di gruppo sul tema dei protisti e del loro coinvolgimento nella qualit\ue0 dell\u2019ambiente e della salute. 3. Ottenimento della collaborazione tra ricerca universitaria, scuola e aree marine protette in maniera sinergica

    Polyvinylpyridine-supported palladium nanoparticles: An efficient catalyst for Suzuki–Miyaura coupling reactions

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    Palladium nanoparticles (Pd NPs) synthesized by the metal vapor synthesis technique were supported on poly(4-vinylpyridine) 2% cross-linked with divinylbenzene (Pd/PVPy). Transmission electron microscopy revealed the presence of small metal nanoparticles (dm = 2.9 nm) highly dispersed on the PVPy. The Pd/PVPy system showed high catalytic efficiency in Suzuki-Miyaura carbon–carbon coupling reactions of both non-activated and deactivated aromatic iodides and bromides with aryl boronic acids, carried out under an air atmosphere. The high turnover of the catalyst and the ability of the PVPy resin to retain active Pd species are highlighted. By comparing the catalytic performances of Pd/PVPy with those observed by using commercially available Pd-based supported catalysts, the reported system showed higher selectivity and lower Pd leaching

    Macro-habitat preferences by the African manatee and crocodiles – ecological and conservation implications

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    African manatees (<i>Trichechus senegalensis</i>) and crocodiles are threatened species in parts of their range. In West Africa, crocodiles may constitute the main predators for manatees apart from humans. Here, we explore the macro-habitat selection of manatees and two species of crocodiles (West African crocodiles <i>Crocodylus suchus</i> and dwarf crocodile <i>Osteolaemus tetraspis</i>) in the Niger Delta (Nigeria), testing the hypotheses that (i) manatees may avoid crocodiles in order to minimize risks of predation, and (ii) the two crocodile species do compete. The study was carried out between 1994 and 2010 with a suite of different field techniques. We observed that the main macro-habitat types were freshwater rivers and coastal lagoons for manatees, mangroves for West African crocodiles, and rivers and creeks for dwarf crocodiles, with (i) the three species differing significantly in terms of their macro-habitat type selection, and (ii) significant seasonal influence on habitat selection of each species. Null models for niche overlap showed a significantly lower overlap in macro-habitat type use between manatee and crocodiles, whereas the two crocodiles were relatively similar. Null model analyses did not indicate any competitive interactions between crocodiles. On the other hand, manatees avoided macro-habitats where crocodiles, and especially West African crocodiles, are abundant

    Macro-habitat preferences by the African manatee and crocodiles – ecological and conservation implications

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    Abstract. African manatees (Trichechus senegalensis) and crocodiles are threatened species in parts of their range. In West Africa, crocodiles may constitute the main predators for manatees apart from humans. Here, we explore the macro-habitat selection of manatees and two species of crocodiles (West African crocodiles Crocodylus suchus and dwarf crocodile Osteolaemus tetraspis) in the Niger Delta (Nigeria), testing the hypotheses that (i) manatees may avoid crocodiles in order to minimize risks of predation, and (ii) the two crocodile species do compete. The study was carried out between 1994 and 2010 with a suite of different field techniques. We observed that the main macro-habitat types were freshwater rivers and coastal lagoons for manatees, mangroves for West African crocodiles, and rivers and creeks for dwarf crocodiles, with (i) the three species differing significantly in terms of their macro-habitat type selection, and (ii) significant seasonal influence on habitat selection of each species. Null models for niche overlap showed a significantly lower overlap in macro-habitat type use between manatee and crocodiles, whereas the two crocodiles were relatively similar. Null model analyses did not indicate any competitive interactions between crocodiles. On the other hand, manatees avoided macro-habitats where crocodiles, and especially West African crocodiles, are abundant

    Total Synthesis of Asparenydiol by Two Sonogashira Cross-Coupling Reactions Promoted by Supported Pd and Cu Catalysts

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    Asparenydiol, which is an important natural compound with potential pharmacological activities, was synthesized through two Sonogashira cross-coupling reactions catalyzed by supported Pd and Cu catalysts and by a Mitsunobu etherification. The optimization of the Sonogashira couplings allowed the use of catalysts supported on different matrices with good results in terms of catalytic efficiency and yields

    Developing a questionnaire evaluating knowledge, attitudes and behaviors on audit & feedback among general practitioners. A mixed methods study

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    Background: Audit and Feedback (A&F) is one of the most common strategies used to improve quality in healthcare. However, there is still lack of awareness regarding the enabling factors and barriers that could influence its effectiveness. The aim of this study was to develop a questionnaire to measure the knowledge, attitudes and behaviors of general practitioners (GPs) regarding A&F. The study was performed in the context of the EASY-NET program (project code NET-2016-02364191). Methods: The survey was developed according to two steps. Firstly, a scoping review was performed in order to map the literature on the existing similar instruments with the aim of identifying the sub-domains and possible items to include in a preliminary version of the questionnaire. In the second phase, the questionnaire was reviewed by a multidisciplinary group of experts and administrated to a convenience sample in a pilot survey. Results: Ten papers were included in the scoping review. The survey target and development methodology were heterogenous among the studies. The knowledge, attitudes and behaviors domains were assessed in six, nine and seven studies, respectively. In the first step, 126 pertinent items were extracted and categorized as follows: 8 investigated knowledge, 93 investigated attitudes, and 25 investigated behaviors. Then, 2 sub-domains were identified for knowledge, 14 for attitudes and 7 for behavior. Based on these results, a first version of the survey was developed via consensus among two authors and then revised by the multidisciplinary group of experts in the field of A&F. The final version of the survey included 36 items: 8 in the knowledge domain, 19 in the attitudes domain and 9 in the behaviors domain. The results of the pilot study among 15 GPs suggested a good acceptability and item relevance and accuracy, with positive answers totaling 100% and 93.3% in the proposed questions. Conclusions: The methodology used has shown to be a good strategy for the development of the survey. The survey will be administrated before and after the implementation of an A&F intervention to assess both baseline characteristics and changes after the intervention

    A preliminary radiotracking study of movements, activity patterns and habitat use of free-ranging Gaboon vipers, Bitis gabonica

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    Radiotelemetry was employed to study daily movements, activity patterns, macrohabitat use, and substratum selection of four Gaboon vipers (Bitis gabonica), two adult males and two adult females. The study was carried out during the dry season (1st-20th of March, 1998) in south-eastern Nigeria. Transmitters, weighing approximately 4 g, were internally implanted. Gaboon vipers spent considerable time inactive below-ground. There was considerable nocturnal activity in the open in three of four specimens. and considerable above-ground activity during the early moming hours in ali the four radiotracked specimens . These vipers showed a significant preference for the clearings inside dryland rainforest patches, and avoided cultivated lands. Males used a wider spectrum of macrohabitats than females, these latter being confined almost exclusively to dry forest clearings. Home-ranges, calculated by minimum convex polygon method, averaged 1 .6 ha in the males and 0.8 ha in the females. Average daily distances moved were significantly higher in males than in females. ln both sexes, average daily distances moved were significantly higher during night hours than during daylight hours. Courtships, matings, and sexual combats between males were sometimes observed during the study period. These vipers used sometimes the termite nests as sheltersLes mouvements diurnes, les patrons d'activité, l'utilisation des macrohabitats et la sélection des substrats ont été étudiés par radiotélémétrie chez quatre vipères du Gabon (Bitis gabonica) adultes, deux mâles et deux femelles. L'étude a été conduite durant la saison sèche (suivi par radiopistage du 1er au 20 mars 1998) dans le sud-est du Nigéria. Les émetteurs, pesant environ 4 g. ont été implantés dans l'animal. Les vipères radio-équipées restèrent longtemps inactives sous terre. Trois d'entre-elles ont montré une grande activité nocturne en milieu ouvert. Les quatre ont été très actives durant les premières heures du jour. Ces vipères ont évité les terres cultivées et ont affiché une préférence significative pour les chablis dans les parcelles de forêt sêche. Les domaines vitaux moyens, calculés par la méthode du polygone convexe minimum, furent de 1.6 ha pour les mâles et de 0.8 ha pour les femelles. Les distances moyennes parcourues chaque jour furent significativement plus grandes chez les mâles que chez les femelles. Pour les deux sexes, les distances moyennes parcourues quotidiennement furent significativement plus fortes de nuit que de jour. Des parades nuptiales, des accouplements et des affrontements sexuels entre mâles furent parfois observés durant la période d'étude. Les vipères ont parfois utilisé des termitières comme abris
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