1,224 research outputs found
A semiótica dos textos de terror : O discurso que provoca o medo
O trabalho a ser apresentado neste evento é fruto da pesquisa de doutorado da participante, que analisa os oito livros de terror mais vendidos no Brasil, no perÃodo de 1980 a 2007. O suporte teórico metodológico que sustenta as análises do corpus é a semiótica greimasiana. Seu objetivo é expor como o discurso se configura, provocando o efeito de sentido do medo nos textos. Para definir o terror, utiliza-se a teoria de Lovecraft (2008), segundo a qual o gênero se manifesta quando um elemento sobrenatural aparece no mundo real, causando medo. Nao há convivência de dois mundos, mas apenas existe o mundo real, com o sobrenatural inserido nele. Nesta vertente da literatura do medo, os textos sao configurados seguindo uma linha discursiva semelhante, conforme analisa a teoria semiótica, com temas, figuras e estruturas que confluem para o seguinte foco: provocar o medo no leitor. Atualmente, a literatura de terror tem conquistado um espaço cada vez maior no mercado editorial brasileiro. Entre tantos conceitos que a permeiam, é preciso considerar que, na medida em que o texto literário se apodera destes temores, demonstra o alerta, a denúncia, proporcionando o alÃvio da tensao cotidiana do ser humano que, ao pegar uma obra, coloca-se na funçao social de leitor. Esta é uma das hipóteses que justificam a grande vendagem atual de obras de terror. Segundo Bordini (1987), as histórias de terror definem-se pelo efeito irracional que produzem sobre o leitor. E incumbência da semiótica mostrar como este efeito irracional é transformado em discurso. Para este evento, propoe-se definir o terror, situando-o numa linha em que atuaram escritores como Edgar Allan Poe (1840) e Hawthorne (1851), e explicitar como o discurso deste tipo de literatura se configura, fazendo com que o efeito de sentido do medo saia das folhas do livro e atinja seu leito
Nanosensor based on thermal gradient and machine learning for the detection of methanol adulteration in alcoholic beverages and methanol poisoning
Methanol, naturally present in small quantities in the distillation of alcoholic beverages, can lead to serious health problems. When it exceeds a certain concentration, it causes blindness, organ failure, and even death if not recognized in time. Analytical techniques such as chromatography are used to detect dangerous concentrations of methanol, which are very accurate but also expensive, cumbersome, and time-consuming. Therefore, a gas sensor that is inexpensive and portable and capable of distinguishing methanol from ethanol would be very useful. Here, we present a resistive gas sensor, based on tin oxide nanowires, that works in a thermal gradient. By combining responses at various temperatures and using machine learning algorithms (PCA, SVM, LDA), the device can distinguish methanol from ethanol in a wide range of concentrations (1-100 ppm) in both dry air and under different humidity conditions (25-75% RH). The proposed sensor, which is small and inexpensive, demonstrates the ability to distinguish methanol from ethanol at different concentrations and could be developed both to detect the adulteration of alcoholic beverages and to quickly recognize methanol poisonin
PTR-ToF-MS fingerprinting of Italian EVOO
Extra Virgin Olive Oil (EVOO) is the highest quality olive oil available, extracted from the olive fruit without the use of any heat or chemicals. Among the high quality EVOOs recognized by the European Union (Protected Designation of Origin, PDO, and Protected Geographic Identification, PGI), almost the 40% come from Italy with 42 PDO and 4 PGI EVOOS followed by Spain and Greece having 29 recognized EVOOs each. Due to its economic value, high quality EVOO is susceptible to fraud. A high quality EVOO is distinguished for its aroma. Many factors influence the composition in Volatile Organic Compounds (VOCs) such as cultivar, agronomical practices, geographical origins, harvesting periods, processing technologies, storage conditions [1]. The study of volatile compounds could be a way to trace the origin and quality of EVOOs. The gold standard for this task is the use of GC-MS providing detailed information on VOCs profiling. On the other hand, such approach is not always a convenient and practical choice when dealing with large sample set (time and cost consuming). Fast fingerprinting can be a valid alternative, at least as screening tool, to characterize a population fast. Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) was already successfully applied for screening of olive oils [2], apples [3], and other food products allowing a fast screening of large sample set. In the present study, we applied PTR -ToF-MS to obtain a fast VOCs fingerprint of high quality EVOO samples collected within the Violin project (Project AGER2-Rif.2016-0169). Up to now, 200 EVOOs (monovarietals and blends) from 12 Italian regions and three other countries, harvested in two different years, were measured. Preliminary data elaboration suggests the possibility to discriminate EVOOs according to the origin. For example, EVOO from Sicily seems to present a peculiar fingerprint that allows a separation from all other EVOO analyzed to be achieved. On a reduced dataset (for which a sufficient number of samples per each location was available), including EVOOs from Apulia, Sicily, Lazio, and Tuscany, classification models based on Partial Least Squares Discriminant Analysis (PLS-DA) were tested
The physical and structural effects of 1-MCP on four different apple cultivars during storage
The impact of the ethylene inhibitor, 1-methylcyclopropene (1-MCP), on four apple cultivars (Braeburn, Fuji, Jazz and Golden Delicious) over 150 days of storage at 2 °C was assessed. Proton transfer reaction quadrupole mass spectrometry (PTR-QUAD-MS) was used to monitor changes in VOC composition, while texture analysis and X-ray microcomputer tomography (µ-CT) scanning were used to study microstructural changes. The application of 1-MCP on apples reduced VOC emissions, concurrently maintaining a firmer texture compared to the untreated apples at each time point. The µ-CT scanning revealed how changes in specific morphological characteristics such as anisotropy, connectivity and porosity, size and shape, as well as the interconnectivity of intracellular spaces (IS) influenced texture even when porosity was similar. Additionally, this study showed that the porosity and connectivity of IS were associated with VOC emission and increased simultaneously. This study highlights how the morphological parameters of an apple can help explain their ripening process during long-term storage and how their microstructure can influence the release of VOC
Oral processing behaviours of liquid, solid and composite foods are primarily driven by texture, mechanical and lubrication properties rather than by taste intensity
The aim of this study was to understand the influence of saltiness and sweetness intensity on oral processing behaviours of liquid, solid and composite foods. As salty foods, tomato sauce (liquid), penne pasta (solid) and their combination (composite food) were used at two levels of saltiness intensity (low/high). As sweet foods, strawberry sauce (liquid), milk gels (solid) and their combination (composite foods) were used at two levels of sweetness intensity (low/high). Saltiness, sweetness, hardness, chewiness, and liking were quantified using generalized labelled magnitude scales (gLMS). Oral processing behaviours were determined using video recordings (n = 39, mean age 25 ± 3 years) in a home-use-test (HUT) providing fixed bite sizes for all foods. As expected, taste intensity differed significantly between samples within the same food category. No significant effects of taste intensity on oral processing behaviours were found for sweet and salty foods. As expected, consistency strongly affected the consumption time per bite, number of chews per bite, number of chews per gram and eating rate. Solid foods were masticated for the longest time with the highest number of chews per bite, followed by composite foods as the liquid added to the solid foods enhanced lubrication. Liquid foods were masticated for the shortest time. We conclude that large differences in saltiness and sweetness intensity of liquid, solid and composite foods cause no differences in oral processing behaviours. We suggest that oral processing behaviours are primarily driven by texture, mechanical and lubrication properties of foods rather than by their taste intensity.4openYesGonzalez-Estanol, Karina; Libardi, Maddalena; Biasioli, Franco; Stieger, MarkusGonzalez-Estanol, K.; Libardi, M.; Biasioli, F.; Stieger, M
A mechanism for biogenic production and emission of MEK from MVK decoupled from isoprene biosynthesis
Methyl ethyl ketone (MEK) is an important compound in atmospheric chemistry. While attention has been paid mostly to anthropogenic sources of MEK, recently it has been shown that biogenic sources are globally as important as anthropogenic ones. However, the origin of biogenic MEK has yet to be completely elucidated. We present the full mechanism by which within-plant transformation of methyl vinyl ketone (MVK) and, to a minor extent, of 2-butanol and 3-buten-2-ol, is a source of biogenic MEK. Such transformation is observed in red oak for both exogenous MVK, taken up from the atmosphere, and endogenous MVK generated within a plant when it experiences stress (e.g. heat stress). Endogenous MVK emitted by plants is typically explained by within-plant oxidation of isoprene caused by oxidative stress. In this study we show that MVK and MEK emissions caused by heat stress are not related to isoprene in isoprene-emitting plants, implying that the massive carbon investment that plants commit to isoprene production is not explained by a direct antioxidant role. The presented mechanism can be important for inclusion in plant emission and in plant–atmosphere interaction model
High-throughput volatilome fingerprint using PTR–ToF–MS shows species-specific patterns in Mortierella and closely related genera
In ecology, Volatile Organic Compounds (VOCs) have a high bioactive and signaling potential. VOCs are not only metabolic products, but are also relevant in microbial cross talk and plant interaction. Here, we report the first large-scale VOC study of 13 different species of Mortierella sensu lato (s.l.) isolated from a range of different alpine environments. Proton Transfer Reaction–Time-of-Flight Mass Spectrometry (PTR–ToF–MS) was applied for a rapid, high-throughput and non-invasive VOC fingerprinting of 72 Mortierella s.l. isolates growing under standardized conditions. Overall, we detected 139 mass peaks in the headspaces of all 13 Mortierella s.l. species studied here. Thus, Mortierellas.l. species generally produce a high number of different VOCs. Mortierella species could clearly be discriminated based on their volatilomes, even if only high-concentration mass peaks were considered. The volatilomes were partially phylogenetically conserved. There were no VOCs produced by only one species, but the relative concentrations of VOCs differed between species. From a univariate perspective, we detected mass peaks with distinctively high concentrations in single species. Here, we provide initial evidence that VOCs may provide a competitive advantage and modulate Mortierella s.l. species distribution on a global scal
A novel isoprene synthase from the monocot tree Copernicia prunifera (Arecaceae) confers enhanced drought tolerance in transgenic Arabidopsis
The capacity to emit isoprene, among other stresses, protects plants from drought, but the molecular mechanisms underlying this trait are only partly understood. The Arecaceae (palms) constitute a very interesting model system to test the involvement of isoprene in enhancing drought tolerance, as their high isoprene emissions may have contributed to make them hyperdominant in neotropical dry forests, characterized by recurrent and extended periods of drought stress. In this study we isolated and functionally characterized a novel isoprene synthase, the gene responsible for isoprene biosynthesis, from Copernicia prunifera, a palm from seasonally dry tropical forests. When overexpressed in the non-emitter Arabidopsis thaliana, CprISPS conferred significant levels of isoprene emission, together with enhanced tolerance to water limitation throughout plant growth and development, from germination to maturity. CprISPS overexpressors displayed higher germination, cotyledon/leaf greening, water usage efficiency, and survival than WT Arabidopsis under various types of water limitation. This increased drought tolerance was accompanied by a marked transcriptional up-regulation of both ABA-dependent and ABA-independent key drought response genes. Taken together, these results demonstrate the capacity of CprISPS to enhance drought tolerance in Arabidopsis and suggest that isoprene emission could have evolved in Arecaceae as an adaptive mechanism against drough
Configuração discursiva: uma nova proposta terminológica para compilação de textos formal e tematicamente semelhantes
By conceptualizing text, several perspectives can be taken as the basis, such as Textual Linguistics, Discourse Analysis, Semiotics. Thus, each chain sees, defines and analyzes the text under the vision of its theorists and their concepts. So, the terms that are given to the concepts established by each theory are also private and can differentiate between them, even though defining the same object. According to common sense, the group of texts with similar formal and thematically characteristics receives the name of gender or theme, however, it is proposed, with this paper, that it is a discursive configuration, differentiating the concept of gender, according to Bakhtin (1997), Marcuschi (2002), Fontanille (1999) and Fairclough (2001), and the concept of theme, according to Fiorin (1989) and Greimas and Courtés (1979), of the notion of discursive configuration, proposed by Greimas semiotic theory.Ao se conceitualizar o texto, diversas perspectivas podem ser tomadas como base, como a LinguÃstica Textual, a Análise do Discurso, a Semiótica. Dessa forma, cada corrente enxerga, define e analisa o texto sob a visão de seus teóricos e de seus conceitos. Sendo assim, os termos que são dados aos conceitos estabelecidos por cada teoria são, também, particulares, podendo se diferenciar entre elas, ainda que definindo um mesmo objeto. De acordo com o senso comum, o grupo de textos com caracterÃsticas formal e tematicamente semelhantes recebe o nome de gênero ou tema, no entanto, propõe-se, com este trabalho, que se trate de uma configuração discursiva, diferenciando o conceito de gênero, segundo Bakhtin (1997), Marcuschi (2002), Fontanille (1999) e Fairclough (2001), e o conceito de tema, segundo Fiorin (1989) e Greimas e Courtés (1979), da noção de configuração discursiva, proposta pela teoria semiótica greimasiana
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