1,382 research outputs found
Eye-movements reveal semantic interference effects during the encoding of naturalistic scenes in long-term memory
Similarity-based semantic interference (SI) hinders memory recognition. Within long-term visual memory paradigms, the more scenes (or objects) from the same semantic category are viewed, the harder it is to recognize each individual instance. A growing body of evidence shows that overt attention is intimately linked to memory. However, it is yet to be understood whether SI mediates overt attention during scene encoding, and so explain its detrimental impact on recognition memory. In the current experiment, participants watched 372 photographs belonging to different semantic categories (e.g., a kitchen) with different frequency (4, 20, 40 or 60 images), while being eye-tracked. After 10 minutes, they were presented with the same 372 photographs plus 372 new photographs and asked whether they recognized (or not) each photo (i.e., old/new paradigm). We found that the more the SI, the poorer the recognition performance, especially for old scenes of which memory representations existed. Scenes more widely explored were better recognized, but for increasing SI, participants focused on more local regions of the scene in search for its potentially distinctive details. Attending to the centre of the display, or to scene regions rich in low-level saliency was detrimental to recognition accuracy, and as SI increased participants were more likely to rely on visual saliency. The complexity of maintaining faithful memory representations for increasing SI also manifested in longer fixation durations; in fact, a more successful encoding was also associated with shorter fixations. Our study highlights the interdependence between attention and memory during high-level processing of semantic information
Metabolic Syndrome, Thyroid Function and Autoimmunity - The PORMETS Study
Background: The prevalence of thyroid dysfunction and autoimmunity in the Portuguese population has not yet been estimated. However, the national prevalence of the metabolic syndrome remains high. The association of thyroid pathology with cardiovascular risk has been addressed but is still unclear. Our study aimed to evaluate the prevalence of thyroid dysfunction and autoimmunity and to assess the associations of thyroid-stimulating hormone and thyroid hormones and antibodies with metabolic syndrome, its components, and other possible determinants in a national sample.
Material and Methods: The present study included a subsample of 486 randomly selected participants from a nationwide cross-sectional study sample of 4095 adults. A structured questionnaire was administered on past medical history and socio-demographic and behavioural characteristics. Blood pressure and anthropometric measurements were collected, and the serum lipid profile, glucose, insulin, hs- CRP, TSH, FT4, FT3 and thyroid antibodies were measured.
Results: In our sample, the prevalence of hypothyroidism, hyperthyroidism and undiagnosed dysfunction was 4.9%, 2.5% and 72.2%, respectively. Overall, the prevalence of positivity for the thyroid peroxidase and thyroglobulin antibodies was 11.9% and 15.0%, respectively. A positive association was found between free triiodothyronine and metabolic syndrome (OR: 2.019; 95% CI: 1.196, 3.410). Additionally, thyroid peroxidase antibodies had a negative association with metabolic syndrome (OR: 0.465; 95% CI: 0.236, 0.917) and its triglyceride component (OR: 0.321; 95% CI: 0.124, 0.836).
Conclusion: The prevalence of undiagnosed thyroid dysfunction and autoimmunity was high. Thyroid peroxidase antibodies were negatively associated with metabolic syndrome and its triglyceride component, whereas the free triiodothyronine level was positively associated with metabolic syndrome
Efeito das auxinas 2,4-D e TDZ na indução da embriogênese somática em Uncaria tomentosa a partir de ápice caulinar.
O objetivo desse trabalho foi avaliar o efeito das auxinas 2,4-D e TDZ na indução da embriogênese somática utilizando ápice caulinar de U. tomentosa
Embriogênese somática em Uncaria tomentosa a partir de folhas imaturas.
O objetivo desse trabalho foi induzir a embriogênese somática a partir de folhas imaturas de U. tomentosa de plântulas germinadas in vitro
An empirical study on influencers and their engagement factors: The YouTubers' perspective
The current marketing arena is witnessing that the use of influencers or third-party content-generators is an efficient practice. Adding the fact that one of the arising-stars platforms in the social media spectrum is YouTube, the current research aims to understand how YouTube influencers can contribute to the process of customer engagement. The present research methodology is based on a qualitative approach through in-depth interviews of 22 female Youtubers devoted to the lifestyle categories. The questionnaire was built upon existing literature, aiming to understand what are the engagement factors that influencers should rely on to promote engagement from followers with the focal advertised object (i.e., product, brand). But this time from the Youtubers perspective. From the development of this study, a set of customer engagement factors arise. Based on the results we can claim that having an informal relationship with brands, presenting different content from others in the industry, or having a well-connected relationship with followers are engagement factors that contribute to customer engagement.info:eu-repo/semantics/publishedVersio
How influencers and digital interaction can impact customer-brand relationship and engagement
This research seeks to unveil how YouTube influencers and digital interaction can
contribute to the process of customer-brand relationship and engagement. Based on
in-depth interviews of female Youtubers devoted to the lifestyle categories, we aim to
comprehend the engagement factors that influencers should rely on to promote
engagement between their followers and the brands they advocate.info:eu-repo/semantics/publishedVersio
Utilização do ácido girebélico (AG3) do desenvolvimento in vitro de embriões zigóticos de seringueira (Hevea spp.).
A formação de mudas de seringueira ocorre pela enxertia, processo que visa conectar duas partes diferentes em uma única planta. A utilização de sementes que apresentem características similares se torna muito importante para a produção de porta-enxerto homogêneos e vigorosos. O presente trabalho teve como objetivo avaliar o efeito do ácido giberélico (AG3) no desenvolvimento de embriões zigóticos imaturos de seringueira (Hevea ssp). Sementes oriundas de frutos imaturos tiveram seus tegumentos retirados, em seguida as amêndoas foram lavadas em água destilada e então ocorreu a retirada dos embriões zigóticos imaturos, estes foram desinfestados em câmara de fluxo laminar mediante a imersão dos mesmos em álcool 70% por 15 segundos e solução de hipoclorito de sódio 1% por 10 minutos, sendo em seguida lavados por três vezes em água destilada e autoclavada e inoculados em meio de cultura WPM contendo várias concentrações de AG3 (T1 - 0; T2 - 0,5; T3 - 0,75; T4 - 1; T5 - 1,5; T6 - 2; T7 - 2,5 e T 8- 3 mg.L-1). A utilização do AG3 no meio de cultura promoveu maior desenvolvimento de embriões imaturos desta espécie
Invasion success of a Lessepsian symbiont-bearing foraminifera linked to high dispersal ability, preadaptation and suppression of sexual reproduction
Among the most successful Lessepsian invaders is the symbiont-bearing benthic foraminifera Amphistegina lobifera. In its newly conquered habitat, this prolific calcifier and ecosystem engineer is exposed to environmental conditions that exceed the range of its native habitat. To disentangle which processes facilitated the invasion success of A. lobifera into the Mediterranean Sea we analyzed a ~ 1400 bp sequence fragment covering the SSU and ITS gene markers to compare the populations from its native regions and along the invasion gradient. The genetic variability was studied at four levels: intra-genomic, population, regional and geographical. We observed that the invasion is not associated with genetic differentiation, but the invasive populations show a distinct suppression of intra-genomic variability among the multiple copies of the rRNA gene. A reduced genetic diversity compared to the Indopacific is observed already in the Red Sea populations and their high dispersal potential into the Mediterranean appears consistent with a bridgehead effect resulting from the postglacial expansion from the Indian Ocean into the Red Sea. We conclude that the genetic structure of the invasive populations reflects two processes: high dispersal ability of the Red Sea source population pre-adapted to Mediterranean conditions and a likely suppression of sexual reproduction in the invader. This discovery provides a new perspective on the cost of invasion in marine protists: The success of the invasive A. lobifera in the Mediterranean Sea comes at the cost of abandonment of sexual reproduction
Enraizamento in vitro das especies P. hispidinervum e P. aduncum utilizando diferentes concentrações de AIA.
A pimenta longa (Piper hispidinervum) e a pimenta de macaco (Piper aduncum) são espécies pertencentes à família botânica das Piperaceas e encontram-se entre as plantas aromáticas que fornecem óleo essencial rico nos respectivos compostos secundários, safrol e dilapiol, substâncias amplamente utilizadas em diversos setores industriais. O objetivo deste trabalho foi avaliar o efeito de diferentes concentrações do ácido indolilacético-AIA (0,0; 0,25; 0,5; 0,75; 1,0 e 2,0 mg.L-1) no enraizamento in vitro destas espécies. Brotos oriundos de plântulas germinadas in vitro foram inoculados em meio semi-sólido MS pleno com 3% de sacarose e suplementado com diversas concentrações do AIA. As culturas foram mantidas em sala de crescimento à temperatura controlada de 25+2ºC, expostas ao fotoperíodo de 16 horas de luz com intensidade luminosa de 30 umol.m2.s-1. Após 50 dias de incubação foram avaliadas as seguintes variáveis: porcentagem de enraizamento, comprimento da raiz principal, comprimento da parte aérea, número de folhas e número de raízes. O delineamento experimental utilizado foi inteiramente casualizado, com 6 repetições por tratamento e 4 explantes por repetição. Obteve-se 100% de enraizamento em todos os tratamentos utilizados para as duas espécies. As raízes surgidas apresentavam-se esbranquiçadas e com ramificações, indicando a formação de um sistema radicular eficiente, fato que sugere que esta planta não necessita da adição de auxina exógena
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