974 resultados para Bernardi Claraevallensis


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BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus . RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality > 80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii . Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40?60%) and low mortality for Z. indianus (mortality < 23%); however, these compounds reduced the larval infestation of the two species by 55?86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality < 40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvaeandadultsof D. suzukii and Z.indianus .Theuseoftoxicbaitsforadultsof D. suzukii couldbeanalternativeinmanagement of this species. © 2016 Society of Chemical Industry Keywords: spotted-wing drosophila; fig fly; chemical control; strawberry; toxic bait; pest control.

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Resumo: Drosophila suzukii (Matsumura) foi recentemente detectado causando danos idade para morangos no Brasil. Infestação na cultura de morango tem frequentemente foi observado conjuntamente com a presença de Zaprionus indianus Gupta. este estudo investigou a suscetibilidade de morangos em três amadurecimento estágios para infestação de D. suzukii e Z. indianus e sua interação. Abstracts: Drosophila suzukii (Matsumura) has been recently detected causing damage to strawberries in Brazil. Infestation in strawberry culture has often been observed jointly with the presence of Zaprionus indianus Gupta. This study investigated the susceptibility of strawberries at three ripening stages to infestation of D. suzukii and Z. indianus and their interaction. In the laboratory, strawberries cv. Albion at different ripening stages (green, semi-ripe and ripe) were exposed to D. suzukii and Z. indianus for 24 h in choice and no-choice bioassays. Additionally, we evaluated the effects of mechanical damage incurred artificially or by D. suzukii ovi-position on Z. indianus infestation. In no-choice bioassay, there were no significant differences in fruit susceptibility to D. suzukii infestation at different ripening stages. However, in choice bioassay, D. suzukii adults preferred to oviposit on R fruit. The presence of mechanical damage did not increase susceptibility of fruit to D. suzukii oviposition. For Z. indianus , there was greater susceptibility of R fruit in relation to SR and G fruit in both the choice and no-choice bioassays. There was a significant and positive interaction of mechanical damage and damage caused by D. suzukii to R fruit and infestation by Z. indianus , which was not observed in SR and G fruit. Although infestation of Z. indianus is related to attack damaged or decaying fruit, this work shows that this species has the ability to oviposit and develop in healthy strawberry fruit with and increased infestation level when the fruit has damage to its epidermis.

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2008

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La presente ricerca di dottorato, attraverso un’indagine multidisciplinare, si pone l’obiettivo di elaborare in chiave pedagogica una riflessione sulla relazione esistente tra la letteratura per l’infanzia, la narrazione, l’esperienza e il limite. La ricerca mira ad analizzare le metafore del limite intese come metafore della caducità, della ferita, della marginalità, della liminalità, della divergenza e dell’alterità. La ricerca si concentra in particolare sulle rappresentazioni metaforiche della relazione educativa tra personaggi mentori e personaggi bambini, colti in attraversamenti e transizioni esistenziali, colti quindi nell’atto di cura della loro natura limitata. L’impianto teorico-interpretativo elaborato è utilizzato per sondare criticamente l’opera di Robert Louis Stevenson e di James Matthew Barrie, autori scelti come rappresentanti emblematici del periodo di soglia a cavallo di secolo, compreso tra il 1880 e il 1914. Attraverso l’applicazione del paradigma indiziario della ricerca storiografica e letteraria, l’indagine raccoglie correlazioni incongrue tra le opere, le biografie e la storia in cui esse si inseriscono, per formulare ipotesi che permettano un’interpretazione delle modificazioni che le rappresentazioni del limite subirono in quel periodo, sul limitare del primo conflitto mondiale.

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Il presente lavoro di tesi, inscritto in un’ottica pedagogica interdisciplinare che si sviluppa attraverso il paradigma indiziario, si propone di svolgere una riflessione attorno alla «parola poetica» nell’ottica di un’educazione estetica dell’infanzia che passi anche dalla scoperta di un linguaggio polisemico, metaforico, complesso, lieve quale quello poetico. Concetti quali la marginalità e l’alterità del dire poetico e della figura stessa del poeta, che dà voce al momento liminale della communitas, si fanno rivelatori di quella che si mostra come vera e propria “parola magica” capace di dare senso, nel mito e nel rito che costantemente lo rigenera, all’esperienza umana. La ricerca prende quindi in esame alcuni momenti paradigmatici, nella storia dell’immaginario e nella riflessione letteraria occidentale, che hanno favorito l’incontro fra poesia e infanzia nel terreno di una parola che dà voce alla liminalità: da Rousseau a Pascoli, da Baudelaire a Stevenson, numerosi sono gli autori che conducono la riflessione fino a quel territorio di soglia proficuamente spaesante che è la poesia «autentica» per l’infanzia contemporanea. In particolare, questa ricerca prende in esame la collana di poesia della casa editrice Topipittori significativamente denominata “Parola magica”. Ventidue titoli, riconducibili alle due tipologie testuali che C. Boutevin definisce «raccolta di poesie illustrata» e «albo-poesia», permettono un affondo nella poesia contemporanea per l’infanzia, che esprime in questa collana la propria dimensione di soglia: l’interdipendenza fra parola e immagine e la diffusa presenza di «tracce di fiaba» ne sono i principali indizi analizzati in questo lavoro.

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The disintegration of stone materials used in sculpture and architecture due to the crystallization of salts is capable of irreparably damaging artistic objects and historic buildings. A number of phosphonates and carboxylates were tested here as potential crystallization modifiers for sodium carbonate crystallization. Precipitated phases during crystallization induced either by cooling or by evaporation tests were nahcolite (NaHCO3), natron (Na2CO3∙10H2O) and thermonatrite (Na2CO3∙H2O), identified using X-ray diffraction. By using the thermodynamic code PHREEQC and the calculation of the nucleation rate it was demonstrated that nahcolite had to be first phase formed during both tests. The formation of the other phases depended on the experimental conditions under which the two tests were conducted. Nahcolite nucleation is strongly inhibited in the presence of sodium citrate tribasic dihydrate (CA), polyacrylic acid 2100MW (PA) and etidronic acid (HEDP), when the additives are dosed at appropriate concentrations and the pH range of the resulting solution is about 8. Electrostatic attraction generated between the deprotonated organic additives and the cations present in solution appears to be the principal mechanism of additive-nahcolite interaction. Salt weathering tests, in addition to mercury intrusion porosimetry tests allowed to quantify the damage induced by such salts. FESEM observation of both salts grown on calcite single crystals and in limestone blocks subjected to salt crystallization tests allowed to identify the effect of these additives on crystal growth and development. The results show that PA seems to be the best inhibitor, while CA and HEDP, which show similar behaviors, are slightly less effective. The use of such effective crystallization inhibitors may lead to more efficient preventive conservation of ornamental stone affected by crystallization damage due to formation of sodium carbonate crystals.

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Incorporation of the relevant monosaccharide N-Acetyl-D-glucosamine (GlcNAc) into synthetic oligosaccharides by chemical glycosylation is still a very challenging object of studies, since direct reactions are low yielding. This issue is generally ascribed to its low solubility in common solvents and to the formation of a poorly reactive oxazoline intermediate, which is typically bypassed by introducing extra synthetic steps to avoid the presence of the NHAc moiety during glycosylation. Recently, a new direct Lewis acids-catalysed GlcNAc-ylation protocol has been disclosed, with acylated donors appearing to hold potential for high yielding glycosylation reactions. This master project focused indeed on a novel synthesis of promising 1-acyl GlcNAc donors, in order to test them in direct Lewis acid catalysed glycosylation without the need of N-protecting groups. Screening of various Lewis acids and reaction conditions with these acylated donors has been carried out, in presence of reactive primary alcohols as well as more challenging carbohydrate acceptor alcohols. These experiments demonstrated that the fine tuning of the leaving group combined with a suitable metal triflate could lead to a successful reaction outcome in the direct glycosylation. Successful methodology of this kind would provide rapid access to naturally occurring N-glycan motifs, such as the highly relevant human milk oligosaccharides (HMOs).

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Airborne Particulate Matter (PM), can get removed from the atmosphere through wet and dry mechanisms, and physically/chemically interact with materials and induce premature decay. The effect of dry depositions is a complex issue, especially for outdoor materials, because of the difficulties to collect atmospheric deposits repeatable in terms of mass and homogeneously distributed on the entire investigated substrate. In this work, to overcome these problems by eliminating the variability induced by outdoor removal mechanisms (e.g. winds and rainfalls), a new sampling system called ‘Deposition Box’, was used for PM sampling. Four surrogate materials (Cellulose Acetate, Regenerated Cellulose, Cellulose Nitrate and Aluminum) with different surfaces features were exposed in the urban-marine site of Rimini (Italy), in vertical and horizontal orientations. Homogeneous and reproducible PM deposits were obtained and different analytical techniques (IC, AAS, TOC, VP-SEM-EDX, Vis-Spectrophotometry) were employed to characterize their mass, dimension and composition. Results allowed to discriminate the mechanisms responsible of the dry deposition of atmospheric particles on surfaces with different nature and orientation and to determine which chemical species, and in which amount, tend to preferentially deposit on them. This work demonstrated that “Deposition Box” can represent an affordable tool to study dry deposition fluxes on materials and results obtained will be fundamental in order to extend this kind of exposure to actual building and heritage materials, to investigate the PM contribution in their decay.

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Deterioration phenomena occurring on outdoor cultural heritage have been the subject of several studies, but relatively few works investigated the specific role of Particulate Matter (PM) in the corrosion of metals. This topic is really complex and, besides field exposures, accelerated ageing tests are also necessary to isolate and understand deterioration mechanisms due to PM. For this reason, the development of a methodology that allows to reproduce and analyze the effect of PM on alloys through accelerated ageing in climatic chamber has been started. On quaternary bronze specimens, single salts and a mix of them were deposited via two deposition methods: dry (directly depositing the salt on the surface) and wet (dropping a salt solution and drying it), simulating the initial chemical activation of the salts by RH% variations or by raindrops, respectively. Then, to better mimic the composition of real PM, a mixture containing a soluble salts, a mineral, a black carbon and an organic fraction was formulated and spread on the samples. The samples were placed in a climatic chamber and exposed to cyclic variations of T and RH for three weeks. The ageing cycles were set according to predictions on salt deliquescence/recrystallization through E-AIM model and to the evaluation of regional climatic data. The surface evolution was followed by SEM-EDX, Raman, AT-IR and UV-Vis Spectrophotometry. At the end of the test, mass losses were determined and corroded metals removed by pickling were analyzed by AAS. On the basis of the obtained results, the tested procedures seem to be promising in accelerating and mimicking realistic corrosion phenomena, as under the selected conditions, corrosion products typically found at different exposure time (from days to years) on outdoor bronzes were able to progressively form and evolve. Moreover, the two deposition modes simulating different condition of chemical activation of PM deposits allow to obtain complementary information.

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The topic of this thesis concerns the study of catalytic processes for the synthesis of chiral 3,4,5-trisubstituted piperidine and 2,6-disubstituted morpholine. Substrates possessing an α,β-unsaturated ester and a ketone moiety, able to undergo addition/cyclization cascade reactions with different pro-nucleophiles (thiophenols, acetone cyanohydrin and malononitrile), have been evaluated. Chiral and achiral systems for phase-transfer catalysis have been applied as catalysts. Moderate enantiomeric excesses have been obtained for the morpholinic products and good to excellent values for the piperidinic products, by using cyclopeptoids and quaternary ammonium salts derived from Chincona alkaloids as catalysts respectively. Moreover, the absolute configuration of the 3,4,5-trisubstituted piperidines has been determined through quantomechanical simulations of their chirooptical spectra. Finally, the relative configuration of the 2,6-disubstituted morpholines has been assigned through NMR experiments.