1,740 research outputs found
Detecting event-related recurrences by symbolic analysis: Applications to human language processing
Quasistationarity is ubiquitous in complex dynamical systems. In brain
dynamics there is ample evidence that event-related potentials reflect such
quasistationary states. In order to detect them from time series, several
segmentation techniques have been proposed. In this study we elaborate a recent
approach for detecting quasistationary states as recurrence domains by means of
recurrence analysis and subsequent symbolisation methods. As a result,
recurrence domains are obtained as partition cells that can be further aligned
and unified for different realisations. We address two pertinent problems of
contemporary recurrence analysis and present possible solutions for them.Comment: 24 pages, 6 figures. Draft version to appear in Proc Royal Soc
Sugammadex is effective in reversing rocuronium in the presence of antibiotics
Background: The effectiveness of sugammadex in reversing rocuronium-induced neuromuscular blockade (NMB) in the presence of drugs that may potentiate NMB remains to be fully established. The aim of this post-hoc analysis of data from a Phase III clinical trial (VISTA; NCT00298831) was to investigate the impact of antibiotics on recovery from rocuronium-induced NMB after administration of sugammadex for reversal, and compared the neuromuscular recovery in patients who received antibiotics preoperatively with those who did not.Methods: A Phase III, multicenter, open-label study designed to reflect potential use of sugammadex in clinical practice was conducted at 19 sites. Data obtained from patients who received antibiotics were compared with the cohort of patients who underwent the same protocol without antibiotics. Each subject received rocuronium 0.6 mg/kg for muscle relaxation, after which tracheal intubation was performed; patients were also permitted to receive maintenance doses of rocuronium 0.15 mg/kg to maintain the desired level of NMB throughout the operation, as required. At least 15 min after the last rocuronium dose, patients received sugammadex 4.0 mg/kg for reversal. Neuromuscular monitoring was continued until a train-of-four (TOF) ratio of ≥0.9 was achieved or the anesthetic was discontinued.Results: The presence of antibiotics prior to the administration of sugammadex did not affect the recovery time from rocuronium-induced NMB when sugammadex 4.0 mg/kg was administered at least 15 min after the last dose of rocuronium. In the presence of antibiotics, the geometric mean (95% CI) time from administration of sugammadex 4.0 mg/kg to recovery of the TOF ratio to ≥0.9 was 1.6 (1.4-1.9) min (range: 0.7-10.5 min), compared with 2.0 (1.8-2.3) min (range: 0.7-22.3 min) for patients who did not receive antibiotics.Conclusions: These findings suggest that prophylactic antibiotic use is unlikely to have a major impact on the recovery time from rocuronium-induced NMB with sugammadex reversal.Trial registration: ClinicalTrials.gov Identifier: NCT00298831
Disfluency in dialogue:an intentional signal from the speaker?
Disfluency is a characteristic feature of spontaneous human speech, commonly seen as a consequence of problems with production. However, the question remains open as to why speakers are disfluent: Is it a mechanical by-product of planning difficulty, or do speakers use disfluency in dialogue to manage listeners' expectations? To address this question, we present two experiments investigating the production of disfluency in monologue and dialogue situations. Dialogue affected the linguistic choices made by participants, who aligned on referring expressions by choosing less frequent names for ambiguous images where those names had previously been mentioned. However, participants were no more disfluent in dialogue than in monologue situations, and the distribution of types of disfluency used remained constant. Our evidence rules out at least a straightforward interpretation of the view that disfluencies are an intentional signal in dialogue. © 2012 Psychonomic Society, Inc
Boundaries of Semantic Distraction: Dominance and Lexicality Act at Retrieval
Three experiments investigated memory for semantic information with the goal of determining boundary conditions for the manifestation of semantic auditory distraction. Irrelevant speech disrupted the free recall of semantic category-exemplars to an equal degree regardless of whether the speech coincided with presentation or test phases of the task (Experiment 1) and occurred regardless of whether it comprised random words or coherent sentences (Experiment 2). The effects of background speech were greater when the irrelevant speech was semantically related to the to-be-remembered material, but only when the irrelevant words were high in output dominance (Experiment 3). The implications of these findings in relation to the processing of task material and the processing of background speech is discussed
Members of the chloride intracellular ion channel protein family demonstrate glutaredoxin-like enzymatic activity
© 2015 Al Khamici et al. The Chloride Intracellular Ion Channel (CLIC) family consists of six evolutionarily conserved proteins in humans. Members of this family are unusual, existing as both monomeric soluble proteins and as integral membrane proteins where they function as chloride selective ion channels, however no function has previously been assigned to their soluble form. Structural studies have shown that in the soluble form, CLIC proteins adopt a glutathione S-transferase (GST) fold, however, they have an active site with a conserved glutaredoxin monothiol motif, similar to the omega class GSTs. We demonstrate that CLIC proteins have glutaredoxin-like glutathione-dependent oxidoreductase enzymatic activity. CLICs 1, 2 and 4 demonstrate typical glutaredoxin-like activity using 2-hydroxyethyl disulfide as a substrate. Mutagenesis experiments identify cysteine 24 as the catalytic cysteine residue in CLIC1, which is consistent with its structure. CLIC1 was shown to reduce sodium selenite and dehydroascorbate in a glutathione-dependent manner. Previous electrophysiological studies have shown that the drugs IAA-94 and A9C specifically block CLIC channel activity. These same compounds inhibit CLIC1 oxidoreductase activity. This work for the first time assigns a functional activity to the soluble form of the CLIC proteins. Our results demonstrate that the soluble form of the CLIC proteins has an enzymatic activity that is distinct from the channel activity of their integral membrane form. This CLIC enzymatic activity may be important for protecting the intracellular environment against oxidation. It is also likely that this enzymatic activity regulates the CLIC ion channel function
Imaging the Two Gaps of the High-TC Superconductor Pb-Bi2Sr2CuO6+x
The nature of the pseudogap state, observed above the superconducting
transition temperature TC in many high temperature superconductors, is the
center of much debate. Recently, this discussion has focused on the number of
energy gaps in these materials. Some experiments indicate a single energy gap,
implying that the pseudogap is a precursor state. Others indicate two,
suggesting that it is a competing or coexisting phase. Here we report on
temperature dependent scanning tunneling spectroscopy of Pb-Bi2Sr2CuO6+x. We
have found a new, narrow, homogeneous gap that vanishes near TC, superimposed
on the typically observed, inhomogeneous, broad gap, which is only weakly
temperature dependent. These results not only support the two gap picture, but
also explain previously troubling differences between scanning tunneling
microscopy and other experimental measurements.Comment: 6 page
Quantum Stochastic Processes and the Modelling of Quantum Noise
This brief article gives an overview of quantum mechanics as a {\em quantum
probability theory}. It begins with a review of the basic operator-algebraic
elements that connect probability theory with quantum probability theory. Then
quantum stochastic processes is formulated as a generalization of stochastic
processes within the framework of quantum probability theory. Quantum Markov
models from quantum optics are used to explicitly illustrate the underlying
abstract concepts and their connections to the quantum regression theorem from
quantum optics.Comment: 14 pages, invited article for the second edition of Springer's
Encyclopedia of Systems and Control (to appear). Comments welcom
Significance of herpesvirus immediate early gene expression in cellular immunity to cytomegalovirus infection
Interstitial pneumonia linked with reactivation of latent human cytomegalovirus due to iatrogenic immunosuppression can be a serious complication of bone marrow transplantation therapy of aplastic anaemia and acute leukaemia1. Cellular immunity plays a critical role in the immune surveillance of inapparent cytomegalovirus infections in man and the mouse1−7. The molecular basis of latency, however, and the interaction between latently or recurrently infected cells and the immune system of the host are poorfy understood. We have detected a so far unknown antigen in the mouse model. This antigen is found in infected cells in association with the expression of the herpesvirus 'immediate early' genes and is recognized by cytolytic T lymphocytes (CTL)8. We now demonstrate that an unexpectedly high proportion of the CTL precursors generated in vivo during acute murine cytomegalovirus infection are specific for cells that selectively synthesize immediate early proteins, indicating an immunodominant role of viral non-structural proteins
The geography of recent genetic ancestry across Europe
The recent genealogical history of human populations is a complex mosaic
formed by individual migration, large-scale population movements, and other
demographic events. Population genomics datasets can provide a window into this
recent history, as rare traces of recent shared genetic ancestry are detectable
due to long segments of shared genomic material. We make use of genomic data
for 2,257 Europeans (the POPRES dataset) to conduct one of the first surveys of
recent genealogical ancestry over the past three thousand years at a
continental scale. We detected 1.9 million shared genomic segments, and used
the lengths of these to infer the distribution of shared ancestors across time
and geography. We find that a pair of modern Europeans living in neighboring
populations share around 10-50 genetic common ancestors from the last 1500
years, and upwards of 500 genetic ancestors from the previous 1000 years. These
numbers drop off exponentially with geographic distance, but since genetic
ancestry is rare, individuals from opposite ends of Europe are still expected
to share millions of common genealogical ancestors over the last 1000 years.
There is substantial regional variation in the number of shared genetic
ancestors: especially high numbers of common ancestors between many eastern
populations likely date to the Slavic and/or Hunnic expansions, while much
lower levels of common ancestry in the Italian and Iberian peninsulas may
indicate weaker demographic effects of Germanic expansions into these areas
and/or more stably structured populations. Recent shared ancestry in modern
Europeans is ubiquitous, and clearly shows the impact of both small-scale
migration and large historical events. Population genomic datasets have
considerable power to uncover recent demographic history, and will allow a much
fuller picture of the close genealogical kinship of individuals across the
world.Comment: Full size figures available from
http://www.eve.ucdavis.edu/~plralph/research.html; or html version at
http://ralphlab.usc.edu/ibd/ibd-paper/ibd-writeup.xhtm
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