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Mickaël Causse Jean-Michel Sénard Jean François Démonet Josette Pastor 《Applied psychophysiology and biofeedback》2010,35(2):115-123
The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the
operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great
challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required;
in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task
performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy
subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves
over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving.
Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more
elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress.
A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced
psychological stress during task performance is a promising way to better monitor operators in complex working situations
to detect mental overload or pejorative stress factor of error. 相似文献
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Ploquin M Petukhova GV Morneau D Déry U Bransi A Stasiak A Camerini-Otero RD Masson JY 《Nucleic acids research》2007,35(8):2719-2733
Genetic analysis of fission yeast suggests a role for the spHop2–Mnd1 proteins in the Rad51 and Dmc1-dependent meiotic recombination pathways. In order to gain biochemical insights into this process, we purified Schizosaccharomyces pombe Hop2-Mnd1 to homogeneity. spHop2 and spMnd1 interact by co-immunoprecipitation and two-hybrid analysis. Electron microscopy reveals that S. pombe Hop2–Mnd1 binds single-strand DNA ends of 3′-tailed DNA. Interestingly, spHop2-Mnd1 promotes the renaturation of complementary single-strand DNA and catalyses strand exchange reactions with short oligonucleotides. Importantly, we show that spHop2-Mnd1 stimulates spDmc1-dependent strand exchange and strand invasion. Ca2+ alleviate the requirement for the order of addition of the proteins on DNA. We also demonstrate that while spHop2-Mnd1 affects spDmc1 specifically, mHop2 or mHop2-Mnd1 stimulates both the hRad51 and hDmc1 recombinases in strand exchange assays. Thus, our results suggest a crucial role for S. pombe and mouse Hop2-Mnd1 in homologous pairing and strand exchange and reveal evolutionary divergence in their specificity for the Dmc1 and Rad51 recombinases. 相似文献
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Planchon S Chambon C Desvaux M Chafsey I Leroy S Talon R Hébraud M 《Journal of proteome research》2007,6(9):3566-3580
Staphylococcus xylosus is a saprophytic bacterium commonly found on skin of mammals but also used for its organoleptic properties in manufacturing of fermented meat products. This bacterium is able to form biofilms and to colonize biotic or abiotic surfaces, processes which are mediated, to a certain extent, by cell-envelope proteins. Thus, the present investigation aimed at evaluating and adapting different existing methods for cell-envelope subproteome analyses of the strain S. xylosus C2a. The protocol selected consisted initially of a lysostaphin treatment producing protoplasts and giving a fraction I enriched in cell wall proteins. A second fraction enriched in membrane proteins was then efficiently recovered by a procedure involving delipidation with a mixture of tributyl phosphate, methanol, and acetone and solubilization with a buffer containing ASB14. Proteins were separated using two-dimensional gel electrophoresis (2-DE) and identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). A total of 168 protein spots was identified corresponding to 90 distinct proteins. To categorize and analyze these proteomic data, a rational bioinformatic approach was carried out on proteins identified within cell envelope of S. xylosus C2a. Thirty-four proteins were predicted as membrane-associated with 91% present, as expected, within fraction II enriched in membrane proteins: 24 proteins were predicted as membranal, 3 as lipoproteins, and 7 as components of membrane protein complex. Eighteen out of 25 (72%) proteins predicted as secreted were indeed identified in fraction I enriched in cell wall proteins: 6 proteins were predicted as secreted via Sec translocon, and the remaining 19 proteins were predicted as secreted via unknown secretion system. Eighty-one percent (25/31) of proteins predicted as cytoplasmic were found in fraction II: 8 were clearly predicted as interacting temporarily with membrane components. By coupling conventional 2-DE and bioinformatic analysis, the approach developed allows fractionating, resolving, and analyzing a significant and important set of cell envelope proteins from a coagulase-negative staphylococcus, that is, S. xylosus C2a. 相似文献
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In this paper we examined plan continuation error (PCE), a well known error made by pilots consisting in continuing the flight
plan despite adverse meteorological conditions. Our hypothesis is that a large range of strong negative emotional consequences,
including those induced by economic pressure, are associated with the decision to revise the flight plan and favor PCE. We
investigated the economic hypothesis with a simplified landing task (reproduction of a real aircraft instrument) in which
uncertainty and reward were manipulated. Heart rate (HR), heart rate variability (HRV) and eye tracking measurements were
performed to get objective clues both on the cognitive and emotional state of the volunteers. Results showed that volunteers
made more risky decisions under the influence of the financial incentive, in particular when uncertainty was high. Psychophysiological
examination showed that HR increased and total HRV decreased in response to the cognitive load generated by the task. In addition,
HR also increased in response to the financially motivated condition. Eventually, fixation times increased when uncertainty
was high, confirming the difficulty in obtaining/interpreting information from the instrument in this condition. These results
support the assumption that risky-decision making observed in pilots can be, at least partially, explained by a shift from
cold to hot (emotional) decision-making in response to economic constraints and uncertainty. 相似文献
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Eukaryotic methionine aminopeptidase type 2 (MetAP2, MetAP2 gene (MAP2)), together with eukaryotic MetAP1, cotranslationally hydrolyzes initiator methionine from nascent polypeptides when the side chain of the second residue is small and uncharged. In this report, we took advantage of the yeast (Saccharomyces cerevisiae) map1 null strain's reliance on MetAP2 activity for the growth and viability to provide evidence of the first dominant negative mutant of eukaryotic MetAP2. Replacement of the conserved His(174) with alanine within the C-terminal catalytic domain of yeast MetAP2 eliminated detectable catalytic activity against a peptide substrate in vitro. Overexpression of MetAP2 (H174A) under the strong GPD promoter in a yeast map1 null strain was lethal, whereas overexpression under the weaker GAL1 promoter slightly inhibited map1 null growth. Deletion mutants further revealed that the N-terminal region of MetAP2 (residues 2-57) is essential but not sufficient for MetAP2 (H174A) to fully interfere with map1 null growth. Together, these results indicate that catalytically inactive MetAP2 is a dominant negative mutant that requires its N-terminal region to interfere with wild-type MetAP2 function. 相似文献
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The first and short synthesis of 16beta-hydroxy-5alpha-cholestane-3,6-dione 1 a metabolite from marine algae, has been achieved in six steps from readily available diosgenin 5. Selective deoxygenation of primary alcohol of triol 6 has been accomplished in one step using Et(3)SiH and catalytic amount of B(C(6)F(5))(3) to produce compound 9 in high yield. Oxidation of 11 with PCC, allowed the introduction of 3,6-ene-dione functionality, and further catalytic hydrogenation and deprotection furnished the 3,6-diketo steroid 1. 相似文献
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J Malmström J Viklund C Slivo A Costa M Maudet C Sandelin G Hiller LL Olsson A Aagaard S Geschwindner Y Xue M Vasänge 《Bioorganic & medicinal chemistry letters》2012,22(18):5919-5923
4-(1,3-Benzothiazol-2-yl)thiophene-2-sulfonamide (4a) was found to be a moderately potent inhibitor of cyclin-dependent kinase 5 (cdk5) from a HTS screen. The synthesis and SAR around this hit is described. The X-ray coordinates of ligand 4a with cdk5 are also reported, showing an unusual binding mode to the hinge region via a water molecule. 相似文献