75 research outputs found
FlowDiv: A new pipeline for analyzing flow cytometric diversity
Background: Flow cytometry (FCM) is one of the most commonly used technologies for analysis of numerous biological systems at the cellular level, from cancer cells to microbial communities. Its high potential and wide applicability led to the development of various analytical protocols, which are often not interchangeable between fields of expertise. Environmental science in particular faces difficulty in adapting to non-specific protocols, mainly because of the highly heterogeneous nature of environmental samples. This variety, although it is intrinsic to environmental studies, makes it difficult to adjust analytical protocols to maintain both mathematical formalism and comprehensible biological interpretations, principally for questions that rely on the evaluation of differences between cytograms, an approach also termed cytometric diversity. Despite the availability of promising bioinformatic tools conceived for or adapted to cytometric diversity, most of them still cannot deal with common technical issues such as the integration of differently acquired datasets, the optimal number of bins, and the effective correlation of bins to previously known cytometric populations. Results: To address these and other questions, we have developed flowDiv, an R language pipeline for analysis of environmental flow cytometry data. Here, we present the rationale for flowDiv and apply the method to a real dataset from 31 freshwater lakes in Patagonia, Argentina, to reveal significant aspects of their cytometric diversities. Conclusions: flowDiv provides a rather intuitive way of proceeding with FCM analysis, as it combines formal mathematical solutions and biological rationales in an intuitive framework specifically designed to explore cytometric diversity.Fil: Wanderley, Bruno M. S.. Universidade Federal do Rio Grande do Norte; BrasilFil: Araújo, Daniel S.. Universidade Federal do Rio Grande do Norte; BrasilFil: Quiroga, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Amado, André M.. Universidade Federal do Rio Grande do Norte; Brasil. Universidade Federal de Juiz de Fora; BrasilFil: Neto, Adrião D. D.. Universidade Federal do Rio Grande do Norte; BrasilFil: Sarmento, Hugo. Universidade Federal do São Carlos; BrasilFil: Metz, Sebastián Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Unrein, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin
Synaptic Homeostasis and Restructuring across the Sleep-Wake Cycle
Sleep is critical for hippocampus-dependent memory consolidation. However, the underlying
mechanisms of synaptic plasticity are poorly understood. The central controversy is on
whether long-term potentiation (LTP) takes a role during sleep and which would be its specific
effect on memory. To address this question, we used immunohistochemistry to measure
phosphorylation of Ca2+/calmodulin-dependent protein kinase II (pCaMKIIα) in the rat
hippocampus immediately after specific sleep-wake states were interrupted. Control animals
not exposed to novel objects during waking (WK) showed stable pCaMKIIα levels
across the sleep-wake cycle, but animals exposed to novel objects showed a decrease during
subsequent slow-wave sleep (SWS) followed by a rebound during rapid-eye-movement
sleep (REM). The levels of pCaMKIIα during REM were proportional to cortical spindles
near SWS/REM transitions. Based on these results, we modeled sleep-dependent LTP on
a network of fully connected excitatory neurons fed with spikes recorded from the rat hippocampus
across WK, SWS and REM. Sleep without LTP orderly rescaled synaptic weights
to a narrow range of intermediate values. In contrast, LTP triggered near the SWS/REM
transition led to marked swaps in synaptic weight ranking. To better understand the interaction
between rescaling and restructuring during sleep, we implemented synaptic homeostasis
and embossing in a detailed hippocampal-cortical model with both excitatory and
inhibitory neurons. Synaptic homeostasis was implemented by weakening potentiation
and strengthening depression, while synaptic embossing was simulated by evoking LTP
on selected synapses. We observed that synaptic homeostasis facilitates controlled
synaptic restructuring. The results imply a mechanism for a cognitive synergy between
SWS and REM, and suggest that LTP at the SWS/REM transition critically influences the effect
of sleep: Its lack determines synaptic homeostasis, its presence causes synaptic
restructuring.: Support obtained from Financiadora de
Estudos e Projetos (http://www.finep.gov.br/) Grant #
01.06.1092.00 to SR; Conselho Nacional de
Desenvolvimento Científico e Tecnológico (http://
www.cnpq.br/): Grants 481506/2007-1, 481351/2011-
6 and 306604/2012-4 to SR, Coordenação de
Aperfeiçoamento de Pessoal de Nível Superior
(http://www.capes.gov.br/) and Ciencias sem
Fronteiras (http://www.cienciasemfronteiras.gov.br/
web/csf/home) to AT and CRC; Fundação de Amparo
à Pesquisa do Rio Grande do Norte (http://wwwfapern.rn.gov.br/): Grant Pronem 003/2011 to SR;
Fundação de Amparo à Pesquisa do Estado de São
Paulo (http://www.fapesp.br/): Grant #2013/ 07699-0 -
Center for Neuromathematics to SR; CMP and VRC
supported by post-doctoral fellowships from
Fundação de Amparo à Pesquisa do Rio Grande do
Norte /CNPq. Additional support obtained from the
Federal University of Rio Grande do Norte (www.ufrn.
br); Ministry of Science, Technology and Innovation
(http://www.mcti.gov.br/); Associação Alberto Santos
Dumont de Apoio à Pesquisa (http://natalneuro.com/
associacao/index.asp); Pew Latin American Fellows
Program (http://www.pewtrusts.org/en/projects/pewlatin-american-fellows/)
to SR; Informatics
Department of the Instituto Federal de Educação,
Ciência e Tecnologia do Rio Grande do Norte (http://
portal.ifrn.edu.br/) to WB. The funders had no role in
study design, data collection and analysis, decision to
publish, or preparation of the manuscrip
La gestion démocratique des écoles: de l´autogouvernement à l’émergence d’une post-démocratie gestionnaire?
O autor assinala três elementos básicos que têm sido historicamente associados à gestão democrática das escolas: eleição, colegialidade, participação na decisão. A combinação ou rejeição de algumas dessas diferentes dimensões, em contextos sociais específicos, pode resultar em várias concepções de gestão
democrática das escolas, desde o autogoverno até à possível ascensão de uma pós-democracia gestionária.The author points out three basic elements that have been
historically associated with the democratic management of schools: election,
collegiality, participation in decision-making. The combination or the rejection
of some of those different dimensions in specific social contexts may result
in various conceptions of democratic management of schools, from selfgovernment
to the possible rise of a managerial post-democracyL’auteur souligne trois éléments de base qui ont été historiquement
associés à la gestion démocratique des écoles: l’élection, la collégialité, la
participation à la décision. La combinaison ou le rejet de certaines de ces
différentes dimensions, dans des contextes sociaux spécifiques, peuvent entraîner des diverses conceptions de la gestion démocratique des écoles, de l’autogouvernement à l’émergence d’une post-démocratie gestionnaire(undefined
Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study
Background
Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave.
Methods
This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs.
Results
Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates.
Conclusions
Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility.
Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)
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