5,869 research outputs found
Alterations in brain connectivity due to plasticity and synaptic delay
Brain plasticity refers to brain's ability to change neuronal connections, as
a result of environmental stimuli, new experiences, or damage. In this work, we
study the effects of the synaptic delay on both the coupling strengths and
synchronisation in a neuronal network with synaptic plasticity. We build a
network of Hodgkin-Huxley neurons, where the plasticity is given by the Hebbian
rules. We verify that without time delay the excitatory synapses became
stronger from the high frequency to low frequency neurons and the inhibitory
synapses increases in the opposite way, when the delay is increased the network
presents a non-trivial topology. Regarding the synchronisation, only for small
values of the synaptic delay this phenomenon is observed
2-(2-methyl-2-nitrovinyl)furan but not furvina interfere with staphylococcus aureus agr quorum-sensing system and potentiate the action of fusidic acid against biofilms
Quorum sensing (QS) plays an essential role in the production of virulence factors, in biofilm formation and antimicrobial resistance. Consequently, inhibiting QS is being consid-ered a promising target for antipathogenic/anti-virulence therapies. This study aims to screen 2-nitrovinylfuran derivatives structurally related to Furvina (a broad-spectrum antibiotic already used for therapeutic purposes) for their effects on QS and in biofilm prevention/control. Furvina and four 2-nitrovinylfuran derivatives (compounds 1–4) were tested to assess the ability to interfere with QS of Staphylococcus aureus using bioreporter strains (S. aureus ALC1742 and ALC1743). The activity of Furvina and the most promising quorum-sensing inhibitor (QSI) was evaluated in biofilm prevention and in biofilm control (combined with fusidic acid). The biofilms were further characterized in terms of biofilm mass, viability and membrane integrity. Compound 2 caused the most significant QS inhibition with reductions between 60% and 80%. Molecular docking simulations indicate that this compound interacts preferentially with the protein hydrophobic cleft in the LytTR domain of AgrA pocket. Metabolic inactivations of 40% for S. aureus ALC1742 and 20% for S. aureus ALC1743 were reached. A 24 h-old biofilm formed in the presence of the QSI increased the metabolic inactivation by fusidic acid to 80%, for both strains. The overall results highlight the effects of compound 2 as well as the potential of combining QSI with in-use antibiotics for the management of skin and soft tissues infections
Complementary action of chemical and electrical synapses to perception
Acknowledgements This study was possible by partial financial support from the following agencies: Fundação Araucária, EPSRC-EP/I032606/1, CNPq No. 441553/2014-1, CAPES No. 17656-12-5 and Science Without Borders Program— Process Nos. 17656125, 99999.010583/2013-00 and 245377/2012-3.Peer reviewedPostprin
Less is more. Adjusting the taxonomy of the polytypic: Mimosa setosa (Leguminosae, Mimosoid).
Métodos para superação da dormência em sementes de taxibranco (Tachigali vulgaris L.F Gomes da Silva E H.C Lima).
O Tachigali vulgaris , conhecido vulgarmente como Taxi - Branco ou Carvoeiro,é uma espécie leguminosa arbórea nativa da Amazônia brasileiraexigente em luz (heliófita) e de rápido crescimento, sua madeira apresenta qualidade superior para lenha e carvão, e tem como principal forma de propagação a via sexuada, apesar da baixa taxa de germinação naturaldas sementes
Modeling electrodialysis and a photochemical process for their integration in saline wastewater treatment.
Oxidation processes can be used to treat industrial wastewater containing non-biodegradable organic compounds. However, the presence of dissolved salts may inhibit or retard the treatment process. In this study, wastewater desalination by electrodialysis (ED) associated with an advanced oxidation process (photo-Fenton) was applied to an aqueous NaCl solution containing phenol. The influence of process variables on the demineralization factor was investigated for ED in pilot scale and a correlation was obtained between the phenol, salt and water fluxes with the driving force. The oxidation process was investigated in a laboratory batch reactor and a model based on artificial neural networks was developed by fitting the experimental data describing the reaction rate as a function of the input variables. With the experimental parameters of both processes, a dynamic model was developed for ED and a continuous model, using a plug flow reactor approach, for the oxidation process. Finally, the hybrid model simulation could validate different scenarios of the integrated system and can be used for process optimization
Atributos microbiológicos, físicos e químicos do solo em cultivos de mandioca sob manejo orgânico.
bitstream/item/66205/1/32001.pdfFERTBIO
Coaches’ cultural intelligence: How do coaches rate themselves and what are their cultural training needs?
Cultural intelligence is the capability of a person to adapt effectively to different cultures. This capability has been investigated in areas such as management, military, and education. However, there are no studies in sport referring to this capability. It is important to study cultural intelligence in sport because of the increased globalisation resulting from coaches’ and athletes’ migration across countries and clubs. This study aimed to develop the CQsport and examine its factorial structure and psychometric properties; and examine coaches’ cultural intelligence and their perceived cross-cultural training needs. Participants were 209 football coaches either with or without international experience. Participants completed an online survey consisting of CQsport and a cross-cultural training needs questionnaire. We used a Multi-Group analysis, within the SEM approach, to test group differences in the CQsport and performed a One-Way ANOVA for comparisons across groups concerning cross-cultural training needs. Coaches with international experience rated themselves with more cultural intelligence in the sports context than coaches with no international experience on the metacognitive, cognitive, motivational and behavioural dimensions. Coaches with international experience also self-rated fewer training needs than coaches without international experience. This study represents the first attempt to examine football coaches’ cultural intelligence and their cross-cultural training needs
Inhomogeneous molecular ring around the B[e] supergiant LHA 120-S 73
We aim to improve our knowledge on the structure and dynamics of the
circumstellar disk of the LMC B[e] supergiant LHA 120-S 73. High-resolution
optical and near-IR spectroscopic data were obtained over a period of 16 and 7
years, respectively. The spectra cover the diagnostic emission lines from
[CaII] and [OI], as well as the CO bands. These features trace the disk at
different distances from the star. We analyzed the kinematics of the individual
emission regions by modeling their emission profiles. A low-resolution
mid-infrared spectrum was obtained as well, which provides information on the
composition of the dusty disk. All diagnostic emission features display
double-peaked line profiles, which we interpret as due to Keplerian rotation.
We find that LHA 120-S 73 is surrounded by at least four individual rings of
material with alternating densities (or by a disk with strongly non-monotonic
radial density distribution). Moreover, we find that the molecular ring must
have gaps or at least strong density inhomogeneities, or in other words, a
clumpy structure. The mid-infrared spectrum displays features of oxygen- and
carbon-rich grain species, which indicates a long-lived, stable dusty disk. We
cannot confirm the previously reported high value for the stellar rotation
velocity. The line profile of HeI 5876 A is strongly variable in both width and
shape and resembles of those seen in non-radially pulsating stars. A proper
determination of the real underlying stellar rotation velocity is hence not
possible. The existence of multiple stable and clumpy rings of alternating
density recalls ring structures around planets. Although there is currently
insufficient observational evidence, it is tempting to propose a scenario with
one (or more) minor bodies or planets revolving around LHA 120-S 73 and
stabilizing the ring system, in analogy to the shepherd moons in planetary
systems.Comment: 14 pages, 13 figure, accepted for pulication in A&
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