3,376 research outputs found
The impact of predictability on dual-task performance and implications for resource-sharing accounts.
The aim of this study was to examine the impact of predictability on dual-task performance by systematically manipulating predictability in either one of two tasks, as well as between tasks. According to capacity-sharing accounts of multitasking, assuming a general pool of resources two tasks can draw upon, predictability should reduce the need for resources and allow more resources to be used by the other task. However, it is currently not well understood what drives resource-allocation policy in dual tasks and which resource allocation policies participants pursue. We used a continuous tracking task together with an audiomotor task and manipulated advance visual information about the tracking path in the first experiment and a sound sequence in the second experiments (2a/b). Results show that performance predominantly improved in the predictable task but not in the unpredictable task, suggesting that participants did not invest more resources into the unpredictable task. One possible explanation was that the re-investment of resources into another task requires some relationship between the tasks. Therefore, in the third experiment, we covaried the two tasks by having sounds 250 ms before turning points in the tracking curve. This enabled participants to improve performance in both tasks, suggesting that resources were shared better between tasks
Automated Analysis of MUTEX Algorithms with FASE
In this paper we study the liveness of several MUTEX solutions by
representing them as processes in PAFAS s, a CCS-like process algebra with a
specific operator for modelling non-blocking reading behaviours. Verification
is carried out using the tool FASE, exploiting a correspondence between
violations of the liveness property and a special kind of cycles (called
catastrophic cycles) in some transition system. We also compare our approach
with others in the literature. The aim of this paper is twofold: on the one
hand, we want to demonstrate the applicability of FASE to some concrete,
meaningful examples; on the other hand, we want to study the impact of
introducing non-blocking behaviours in modelling concurrent systems.Comment: In Proceedings GandALF 2011, arXiv:1106.081
Common Mechanisms Underlying the Proconflict Effects of Corticotropin-Releasing Factor, A Benzodiazepine Inverse Agonist and Electric Foot-Shock
AmyPro: a database of proteins with validated amyloidogenic regions
Soluble functional proteins may transform into insoluble amyloid fibrils that deposit in a variety of tissues. Amyloid formation is a hallmark of age-related degenerative disorders. Perhaps surprisingly, amyloid fibrils can also be beneficial and are frequently exploited for diverse functional roles in organisms. Here we introduce AmyPro, an open-access database providing a comprehensive, carefully curated collection of validated amyloid fibril-forming proteins from all kingdoms of life classified into broad functional categories (http://amypro.net). In particular, AmyPro provides the boundaries of experimentally validated amyloidogenic sequence regions, short descriptions of the functional relevance of the proteins and their amyloid state, a list of the experimental techniques applied to study the amyloid state, important structural/functional/variation/mutation data transferred from UniProt, a list of relevant PDB structures categorized according to protein states, database cross-references and literature references. AmyPro greatly improves on similar currently available resources by incorporating both prions and functional amyloids in addition to pathogenic amyloids, and allows users to screen their sequences against the entire collection of validated amyloidogenic sequence fragments. By enabling further elucidation of the sequential determinants of amyloid fibril formation, we hope AmyPro will enhance the development of new methods for the precise prediction of amyloidogenic regions within proteins
And now what? Changing fields and methodologies during the Covid-19 pandemic: from international mobilities to education
The Covid-19 pandemic and the worldwide lockdown have brought about profound changes to the way in which fieldwork is done. During a time particularly marked by social distancing, how do social scientists cope with the need to alter their methodologies with fields in transition? This essay reflects upon the changes caused by the pandemic, both in the field and in the methodologies adopted by the authors – all in different phases of their PhD research. Drawing from their research areas, it focuses on two main thematic axes, both deeply affected by the current situation: international mobilities (of commodities and people) and education (in Portugal and abroad).info:eu-repo/semantics/publishedVersio
The significance of Lactobacillus crispatus and L. vaginalis for vaginal health and the negative effect of recent sex: a cross-sectional descriptive study across groups of African women
Background: Women in sub-Saharan Africa are vulnerable to acquiring HIV infection and reproductive tract infections. Bacterial vaginosis (BV), a disruption of the vaginal microbiota, has been shown to be strongly associated with HIV infection. Risk factors related to potentially protective or harmful microbiota species are not known.
Methods: We present cross-sectional quantitative polymerase chain reaction data of the Lactobacillus genus, five Lactobacillus species, and three BV-related bacteria (Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia) together with Escherichia coli and Candida albicans in 426 African women across different groups at risk for HIV. We selected a reference group of adult HIV-negative women at average risk for HIV acquisition and compared species variations in subgroups of adolescents, HIV-negative pregnant women, women engaging in traditional vaginal practices, sex workers and a group of HIV-positive women on combination antiretroviral therapy. We explored the associations between presence and quantity of the bacteria with BV by Nugent score, in relation to several factors of known or theoretical importance.
Results: The presence of species across Kenyan, South African and Rwandan women was remarkably similar and few differences were seen between the two groups of reference women in Kenya and South Africa. The Rwandan sex workers and HIV-positive women had the highest Gardnerella vaginalis presence (p = 0.006). Pregnant women had a higher Lactobacillus genus mean log (7.01 genome equivalents (geq)/ml) compared to the reference women (6.08 geq/ml). L. vaginalis (43%) was second to L. iners (81.9%) highly present in women with a normal Nugent score. Recent sexual exposure negatively affected the presence of Lactobacillus crispatus (<0.001), L. vaginalis (p = 0.001), and Lactobacillus genus (p < 0.001). Having more than one sexual partner in the last three months was associated with an increased prevalence of Gardnerella vaginalis (p = 0.044) and L. iners (p = 0.001).
Conclusions: Although the composition of species across the studied African countries was similar, the presence of protective species i.e. Lactobacillus crispatus and L. vaginalis in women with a normal Nugent score appeared lower compared to non-African studies. Furthermore, Lactobacillus species were negatively affected by sexual behavioural. Strategies to support protective Lactobacillus species are urgently needed
Effect of native gastric mucus on in vivo hybridization therapies directed at Helicobacter pylori
Helicobacter pylori infects more than 50% of the worldwide population. It is mostly found deep in the gastric mucus lining of the stomach, being a major cause of peptic ulcers and gastric adenocarcinoma. To face the increasing resistance of H. pylori to antibiotics, antimicrobial nucleic acid mimics are a promising alternative. In particular, locked nucleic acids (LNA)/2'-OMethyl RNA (2'OMe) have shown to specifically target H. pylori, as evidenced by in situ hybridization. The success of in vivo hybridization depends on the ability of these nucleic acids to penetrate the major physical barriers-the highly viscoelastic gastric mucus and the bacterial cell envelope. We found that LNA/2'OMe is capable of diffusing rapidly through native, undiluted, gastric mucus isolated from porcine stomachs, without degradation. Moreover, although LNA/2'OMe hybridization was still successful without permeabilization and fixation of the bacteria, which is normally part of in vitro studies, the ability of LNA/2'OMe to efficiently hybridize with H. pylori was hampered by the presence of mucus. Future research should focus on developing nanocarriers that shield LNA/2'OMe from components in the gastric mucus, while remaining capable of diffusing through the mucus and delivering these nucleic acid mimics directly into the bacteria
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