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111.
Thibault Gateau Gautier Durantin Francois Lancelot Sebastien Scannella Frederic Dehais 《PloS one》2015,10(3)
Working memory is a key executive function for flying an aircraft. This function is particularly critical when pilots have to recall series of air traffic control instructions. However, working memory limitations may jeopardize flight safety. Since the functional near-infrared spectroscopy (fNIRS) method seems promising for assessing working memory load, our objective is to implement an on-line fNIRS-based inference system that integrates two complementary estimators. The first estimator is a real-time state estimation MACD-based algorithm dedicated to identifying the pilot’s instantaneous mental state (not-on-task vs. on-task). It does not require a calibration process to perform its estimation. The second estimator is an on-line SVM-based classifier that is able to discriminate task difficulty (low working memory load vs. high working memory load). These two estimators were tested with 19 pilots who were placed in a realistic flight simulator and were asked to recall air traffic control instructions. We found that the estimated pilot’s mental state matched significantly better than chance with the pilot’s real state (62% global accuracy, 58% specificity, and 72% sensitivity). The second estimator, dedicated to assessing single trial working memory loads, led to 80% classification accuracy, 72% specificity, and 89% sensitivity. These two estimators establish reusable blocks for further fNIRS-based passive brain computer interface development. 相似文献
112.
Raimon Sabate Frederic Rousseau Joost Schymkowitz Salvador Ventura 《PLoS computational biology》2015,11(1)
Typical amyloid diseases such as Alzheimer''s and Parkinson''s were thought to exclusively result from de novo aggregation, but recently it was shown that amyloids formed in one cell can cross-seed aggregation in other cells, following a prion-like mechanism. Despite the large experimental effort devoted to understanding the phenomenon of prion transmissibility, it is still poorly understood how this property is encoded in the primary sequence. In many cases, prion structural conversion is driven by the presence of relatively large glutamine/asparagine (Q/N) enriched segments. Several studies suggest that it is the amino acid composition of these regions rather than their specific sequence that accounts for their priogenicity. However, our analysis indicates that it is instead the presence and potency of specific short amyloid-prone sequences that occur within intrinsically disordered Q/N-rich regions that determine their prion behaviour, modulated by the structural and compositional context. This provides a basis for the accurate identification and evaluation of prion candidate sequences in proteomes in the context of a unified framework for amyloid formation and prion propagation. 相似文献
113.
Jean-Fran?ois Bastin Adeline Fayolle Yegor Tarelkin Jan Van den Bulcke Thales de Haulleville Frederic Mortier Hans Beeckman Joris Van Acker Adeline Serckx Jan Bogaert Charles De Cannière 《PloS one》2015,10(11)
Context
Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass.Methods
Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood).Results
Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity variance was explained by species only (45%) followed by a redundant part between species and regeneration guilds (36%). Despite substantial variation in wood specific gravity profiles among species and regeneration guilds, we found that values from the outer wood were strongly correlated to values from the whole profile, without any significant bias. In addition, we found that wood specific gravity from the DRYAD global repository may strongly differ depending on the species (up to 40% for Dialium pachyphyllum).Main Conclusion
Therefore, when estimating forest biomass in specific sites, we recommend the systematic collection of outer wood samples on dominant species. This should prevent the main errors in biomass estimations resulting from wood specific gravity and allow for the collection of new information to explore the intraspecific variation of mechanical properties of trees. 相似文献114.
115.
Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols 总被引:9,自引:0,他引:9
Paul D’Abzac François Bordas Eric Van Hullebusch Piet N. L. Lens Gilles Guibaud 《Applied microbiology and biotechnology》2010,85(5):1589-1599
The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from
four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic
exchange resin (CER), and CER associated with sonication) and four chemical (ethylenediaminetetraacetic acid, ethanol, formaldehyde
combined with heating, or NaOH) EPS extraction methods was compared to a control extraction protocols (i.e., centrifugation).
The nucleic acid content and the protein/polysaccharide ratio of the EPS extracted show that the extraction does not induce
abnormal cellular lysis. Chemical extraction protocols give the highest EPS extraction yields (calculated by the mass ratio
between sludges and EPS dry weight (DW)). Infrared analyses as well as an extraction yield over 100% or organic carbon content
over 1 g g−1 of DW revealed, nevertheless, a carry-over of the chemical extractants into the EPS extracts. The EPS of the anaerobic granular
sludges investigated are predominantly composed of humic-like substances, proteins, and polysaccharides. The EPS content in
each biochemical compound varies depending on the sludge type and extraction technique used. Some extraction techniques lead
to a slightly preferential extraction of some EPS compounds, e.g., CER gives a higher protein yield. 相似文献
116.
117.
Craig Jamieson Robert A. Campbell Iain A. Cumming Kevin J. Gillen Jonathan Gillespie Bert Kazemier Michael Kiczun Yvonne Lamont Amanda J. Lyons John K.F. Maclean Frederic Martin Elizabeth M. Moir John A. Morrow John Pantling Zoran Rankovic Lynn Smith 《Bioorganic & medicinal chemistry letters》2010,20(20):6072-6075
Starting from lead compound 1, we demonstrate how X-ray structural data can be used to understand SAR and expediently optimize bioavailability in a novel series of AMPA receptor modulators, furnishing 5 with improved bioavailability and robust in vivo activity. 相似文献
118.
Jean-Christophe Ianotto Adrian Tempescul Jean-Richard Eveillard Norbert André Frederic Morel Isabelle Quintin-Roué Christian Berthou 《Journal of hematology & oncology》2010,3(1):1-2
We report a case of a 48-year-old Chinese female with end-stage renal disease and chronic anemia on hemodialysis. Clonazepam was prescribed for myoclonus disorder two weeks prior to her hospitalization. Subsequently, she was hospitalized for neutropenic fever with thrombocytopenia and worsening anemia. Bone marrow examination demonstrated a markedly hypocellular marrow (10-20% total cellularity). Clonazepam was discontinued, with gradual improvement of thrombocytopenia, and neutropenia in 1-2 weeks. To our knowledge, this is the first reported case of pancytopenia associated with clonazepam. We recommend patients taking clonazepam to be monitored with regular complete blood count to check for clinically significant pancytopenia or thrombocytopenia. 相似文献
119.
Jan Bartacek Isabella Manconi Gerardo Sansone Roberta Murgia Piet N.L. Lens 《Nitric oxide》2010,22(2):101-105
Hydrogen sulfide (H2S) inhibits the last step of the denitrification process, i.e. the reduction of nitrous oxide (N2O) to dinitrogen gas (N2), both in natural environments (marine sediments) and industrial processes (activated sludge, methanogenic sludge, BioDeNOx process). In a previously published study, we showed that the inhibitory effect of sulfide to N2O reduction in mixed microbial communities is reversible and can be counteracted by dosing trace amounts of copper. It remained, however, unclear if this was due to copper sulfide precipitation or a retrofitting of the copper containing N2O-reductase (N2OR). The present study aimed to elucidate the mechanism of the restoration of sulfide-inhibited N2O reducing activity by metal addition to a pure Pseudomonas aeruginosa culture. This was done by using other metals (zinc, cobalt and iron) in comparison with copper. Zinc and cobalt clearly alleviated the sulfide inhibition of N2OR to the same extent as copper and the activity restoration was extremely fast (within 15 min, Fig. 3) for zinc, cobalt and copper. This suggests that the alleviation of the inhibitory effect of sulfide is due to metal sulfide precipitation and thus not exclusively limited to Cu. This work also underlines the importance of metal speciation: supply of iron did not restore the N2OR activity because it was precipitated by the phosphates present in the medium and thus could not precipitate the sulfide. 相似文献
120.
Kelly H. Zou Frederic S. Resnic Adheet S. Gogate Silvia Ondategui‐Parra Lucila Ohno‐Machado 《Biometrical journal. Biometrische Zeitschrift》2003,45(7):826-836
Health care utilization and outcome studies call for hierarchical approaches. The objectives were to predict major complications following percutaneous coronary interventions by health providers, and to compare Bayesian and non‐Bayesian sample size calculation methods. The hierarchical data structure consisted of: (1) Strata: PGY4, PGY7, and physician assistant as providers with varied experiences; (2) Clusters: ks providers per stratum; (3) Individuals: ns patients reviewed by each provider. The main outcome event illustrated was mortality modeled by a Bayesian beta‐binomial model. Pilot information and assumptions were utilized to elicit beta prior distributions. Sample size calculations were based on the approximated average length, fixed at 1%, of 95% posterior intervals of the mean event rate parameter. Necessary sample sizes by both non‐Bayesian and Bayesian methods were compared. We demonstrated that the developed Bayesian methods can be efficient and may require fewer subjects to satisfy the same length criterion. 相似文献