bluuebunny/crossref_metadata_2025_split huggingface dataset:
Schizophrenia diagnosis and anterior hippocampal volume make separate contributions to sensory gating
Authors: Thoma Robert J. , Hanlon Faith M. , Petropoulos Helen , Miller Gregory A. , Moses Sandra N. , Smith Ashley , Parks Lauren , Lundy S. Laura , Sanchez Natalie M. , Jones Aaron , Huang Mingxiong , Weisend Michael P. , Cañive Jose M. 
Published: September 2008

AbstractImpaired P50 gating is thought to reflect a core deficit in schizophrenia, but the relevant neural network is not well understood. The present study used EEG and MEG to assess sensory gating and volumetric MRI to measure hippocampal volume to investigate relationships between them in 22 normal controls and 22 patients with schizophrenia. In the schizophrenia group, anterior but not posterior hippocampal volume was smaller, and both the P50 and M50 gating ratios were larger (worse) than in controls. Independent of group, left‐hemisphere M50 gating ratio correlated negatively with left anterior hippocampal volume, and right‐hemisphere M50 gating ratio correlated negatively with right anterior hippocampal volume. Schizophrenia diagnosis predicted M50 gating independent of hippocampal volume. These results are consistent with the finding that hippocampus is a critical part of a fronto‐temporal circuit involved in auditory gating.
RUN/EDIT information processing mode and phasic cardiac acceleration
Authors: Sosnowski Tytus , Rynkiewicz Andrzej 
Published: September 2008

AbstractOur previous research showed that tasks demanding running of ready‐to‐use programs (RUN tasks) caused a greater tonic heart rate increase than did tasks that require problem solving (EDIT tasks). We found also a similar though not so consistent effect in the analysis of phasic cardiac acceleration. The aim of the present study was to replicate the last finding using new experimental tasks. Fifty‐four male secondary school pupils were divided randomly into three experimental groups. Each group performed a different version of a nonsignaled reaction time (RT) task: simple RT, sensory choice RT, and semantic choice RT. Participants had to respond within an established time limit, but this limit was continuously modified in such a way that each participant was given positive feedback in approximately 50% of trials. According to expectations, the simple RT task evoked greater phasic cardiac acceleration than did the choice RT tasks.
Cardiac vagal activity during psychological stress varies with social functioning in older women
Authors: Egizio Victoria B. , Jennings J. Richard , Christie Israel C. , Sheu Lei K. , Matthews Karen A. , Gianaros Peter J. 
Published: September 2008

AbstractThe polyvagal theory states that social behavior is linked to cardiac vagal control. This theory has been tested widely in infants and children, but less so in adults. Thus, we examined if resting or stress‐related changes in high‐frequency heart rate variability (HF‐HRV; a presumed index of vagal control) varied with social functioning in 50 healthy women (mean age 68 years). After completing assessments of social functioning, women were exposed to laboratory stressors with concurrent psychophysiological monitoring. Although stressor‐induced suppression of HF‐HRV was common, women with less stressor‐induced suppression of HF‐HRV reported more positive social functioning. Resting HF‐HRV was not related to social functioning. These findings are at apparent odds with the polyvagal theory; however, they complement prior work suggesting that emotional self‐regulation could plausibly modulate cardiac vagal control in association with social functioning.
Associations between the perception of dyspnea, pain, and negative affect
Authors: Schön Daniela , Dahme Bernhard , Leupoldt Andreas von 
Published: September 2008

AbstractThe perception of dyspnea shares many characteristics with the perception of pain, and both sensations might be linked to affective states. Therefore, the present study investigated the associations between perceived dyspnea, pain, and negative affect during resistive load breathing, the cold‐pressor test, and affective picture viewing in healthy volunteers. Physiological and psychological measures confirmed successful experimental manipulation. There was a positive correlation between perceived dyspnea and pain in the unpleasantness dimension, but not in the intensity dimension, and this was further related to negative affect. These associations might be explained by similarities in the cortical processing of dyspnea, pain, and negative affect. The present findings extend the knowledge on similarities between dyspnea and pain and provide support for theories focusing on the perception of physiologic sensations in the development of affective states.
Perceiving age and gender in unfamiliar faces: Brain potential evidence for implicit and explicit person categorization
Authors: Wiese Holger , Schweinberger Stefan R. , Neumann Markus F. 
Published: September 2008

AbstractWe used repetition priming to investigate implicit and explicit processes of unfamiliar face categorization. During prime and test phases, participants categorized unfamiliar faces according to either age or gender. Faces presented at test were either new or primed in a task‐congruent (same task during priming and test) or incongruent (different tasks) condition. During age categorization, reaction times revealed significant priming for both priming conditions, and event‐related potentials yielded an increased N170 over the left hemisphere as a result of priming. During gender categorization, congruent faces elicited priming and a latency decrease in the right N170. Accordingly, information about age is extracted irrespective of processing demands, and priming facilitates the extraction of feature information reflected in the left N170 effect. By contrast, priming of gender categorization may depend on whether the task at initial presentation requires configural processing.
The Complex Trial Protocol (CTP): A new, countermeasure‐resistant, accurate, P300‐based method for detection of concealed information
Authors: Rosenfeld J. Peter , Labkovsky Elena , Winograd Michael , Lui Ming A. , Vandenboom Catherine , Chedid Erica 
Published: September 2008

AbstractA new P300‐based concealed information test is described. A rare probe or frequent irrelevant stimulus appears in the same trial in which a target or nontarget later appears. One response follows the first stimulus and uses the same button press regardless of stimulus type. A later second stimulus then appears: target or nontarget. The subject presses one button for a target, another for a nontarget. A P300 to the first stimulus indicates probe recognition. One group was tested in 3 weeks for denied recognition of familiar information. Weeks 1 and 3 were guilty conditions; Week 2 was a countermeasure (CM) condition. The probe–irrelevant differences were significant in all weeks, and percent hits were >90%. Attempted CM use was detectable via elevated reaction time to the first stimulus. In a replication, results were similar. False positive rates for both studies varied from 0 to .08, yielding J. B. Grier (1971) A′ values from .9 to 1.0.
Comparing low frequency heart rate variability and preejection period: Two sides of a different coin
Authors: Goedhart Annebet D. , Willemsen G. , Houtveen Jan H. , Boomsma Dorret I. , De Geus Eco J. C. 
Published: September 2008

AbstractIt has been hypothesized that the ratio of heart rate variability in the low‐ (LF) and high‐ (HF) frequency bands may capture variation in cardiac sympathetic control. Here we tested the temporal stability of the LF/HF ratio in 24‐h ambulatory recordings and compared this ratio to the preejection period (PEP), an established measure of cardiac sympathetic control. Good temporal stability was found across a period of 3.3 years (.46<r<.78), but the LF/HF ratio did not show the expected negative correlation to PEP, either between or within subjects. We conclude that the evidence to support the LF/HF ratio as a potential marker of cardiac sympathetic control in epidemiology‐scaled research is currently insufficient.
Influence of successive bouts of fatiguing exercise on perceptual and physiological markers during an incremental exercise test
Authors: Coquart Jeremy B.J. , Legrand Renaud , Robin Sophie , Duhamel Alain , Matran Regis , Garcin Murielle 
Published: September 2008

AbstractThe purpose of this study was to examine the effects of a succession of fatiguing stages, on ratings of perceived exertion (RPE) and estimated time limits (ETL) during an incremental exercise test. Twenty‐seven cyclists performed a continuous incremental test and a discontinuous test with randomized workloads. A linear mixed model was used to compare the RPE, ETL, respiratory gas, heart rate, and blood data obtained during the two exercise tests. RPE and ETL were not significantly different between the tests. Ventilation, breathing frequency, heart rate, and blood lactate concentration were significantly higher during the last incremental test workloads. In conclusion, although the incremental exercise test generated higher cardiorespiratory and muscular workloads than observed during the randomized exercise test, most likely due to a greater fatiguing process, these higher workloads did not influence the perceptual response.
The effects of 28 hours of sleep deprivation on respiratory sinus arrhythmia during tasks with low and high controlled attention demands
Authors: Walker Alexander D. , Muth Eric R. , Odle‐Dusseau Heather N. , Moore De Wayne , Pilcher June J. 
Published: September 2008

AbstractTask performance while sleep deprived may be moderated by the controlled attention required by the task (Pilcher, Band, Odle‐Dusseau, & Muth, 2007). This study examined the effects of 28 h of sleep deprivation on respiratory sinus arrhythmia (RSA) during tasks with low and high controlled attention demands. The results showed that RSA increased throughout the night for both task types, but was consistently reduced during the low compared to high controlled attention tasks. The increase in RSA was linear for the high controlled attention tasks but curvilinear for the low ones. Hence, RSA followed a circadian pattern during the low controlled attention tasks but not the high ones. These results suggest that the effects of sleep deprivation on task performance may be moderated by parasympathetic activity and task type, and this has implications for task assignment during sustained operations that cause sleep deprivation.
Transverse patterning dissociates human EEG theta power and hippocampal BOLD activation
Authors: Meltzer Jed A. , Fonzo Greg A. , Constable R. Todd 
Published: September 2008

AbstractTheta oscillations (4–8 Hz) are often modulated in human electroencephalogram (EEG) studies of memory, whereas overlapping frequencies dominate rodent hippocampal EEG. An emerging parallelism between theta reactivity and hippocampal functional magnetic resonance imaging activation has suggested a homology between theta activity in humans and rodents, representing a process of cortico‐hippocampal interaction involved in memory. In the present study, we investigated EEG reactivity during performance of a relational memory task that induces a negative hippocampal blood oxygenation level dependent (BOLD) signal change, compared to a nonrelational control condition. Relational trials induced theta increases and alpha decreases. Low Resolution Electromagnetic Brain Tomography estimates localized theta and alpha modulation to frontal midline and parietal midline cortices, respectively, both of which exhibit negative BOLD responses in this task. Thus, theta and alpha dynamics are dissociable from positive BOLD activation, and may, in fact, colocalize with negative BOLD responses.
Regulation of DARPP‐32 phosphorylation by three distinct dopamine D1‐like receptor signaling pathways in the neostriatum
Authors: Kuroiwa Mahomi , Bateup Helen S. , Shuto Takahide , Higashi Hideho , Tanaka Masatoshi , Nishi Akinori 
Published: September 2008

AbstractDopamine D1‐like receptors play a key role in dopaminergic signaling. In addition to Gs/olf/adenylyl cyclase (AC)‐coupled D1receptors, the presence of D1‐like receptors coupled to Gq/phospholipase C (PLC) has been proposed. Benzazepine D1receptor agonists are known to differentially activate Gs/olf/AC and Gq/PLC signaling. By utilizing SKF83959 and SKF83822, we investigated the D1‐like receptor signaling cascades, which regulate DARPP‐32 phosphorylation at Thr34 (the PKA‐site) in mouse neostriatal slices. Treatment with SKF83959 or SKF83822 increased DARPP‐32 phosphorylation. The SKF83959‐ and SKF83822‐induced increase in DARPP‐32 phosphorylation was largely, but partially, antagonized by a D1receptor antagonist, SCH23390, and the residual SCH23390‐insensitive increase was abolished by an adenosine A2Areceptor antagonist. In addition, the SKF83959‐induced, SCH23390‐sensitive increase in DARPP‐32 phosphorylation was enhanced by a PLC inhibitor. Analysis in slices from D1R/D2R‐DARPP‐32 mice revealed that both D1receptor agonists regulate DARPP‐32 phosphorylation in striatonigral, but not in striatopallidal, neurons. Thus, dopamine D1‐like receptors are coupled to three signaling cascades in striatonigral neurons: (i) SCH23390‐sensitive Gs/olf/AC/PKA, (ii) adenosine A2Areceptor‐dependent Gs/olf/AC/PKA, and (iii) Gq/PLC signaling. Interestingly, Gq/PLC signaling interacts with SCH23390‐sensitive Gs/olf/AC/PKA signaling, resulting in its inhibition. Three signaling cascades activated by D1‐like receptors likely play a distinct role in dopaminergic regulation of psychomotor functions.
The blood–brain barrier significantly limits eflornithine entry into Trypanosoma brucei brucei infected mouse brain1
Authors: Sanderson Lisa , Dogruel Murat , Rodgers Jean , Bradley Barbara , Thomas Sarah Ann 
Published: September 2008

AbstractDrugs to treat African trypanosomiasis are toxic, expensive and subject to parasite resistance. New drugs are urgently being sought. Although the existing drug, eflornithine, is assumed to reach the brain in high concentrations, little is known about how it crosses the healthy and infected blood–brain barrier. This information is essential for the design of drug combinations and new drugs. This study used novel combinations of animal models to address these omissions. Eflornithine crossed the healthy blood–CNS interfaces poorly, but this could be improved by co‐administering suramin, but not nifurtimox, pentamidine or melarsoprol. Work using a murine model of sleeping sickness demonstrated that Trypanosoma brucei brucei crossed the blood–CNS interfaces, which remained functional, early in the course of infection. Concentrations of brain parasites increased during the infection and this resulted in detectable blood–brain barrier, but not choroid plexus, dysfunction at day 28 post‐infection with resultant increases in eflornithine brain delivery. Barrier integrity was never restored and the animals died at day 37.9 ± 1.2. This study indicates why an intensive treatment regimen of eflornithine is required (poor blood–brain barrier penetration) and suggests a possible remedy (combining eflornithine with suramin). The blood–brain barrier retains functionality until a late, possibly terminal stage, of trypanosoma infection.
Activation and membrane binding of retinal protein kinase Bα/Akt1 is regulated through light‐dependent generation of phosphoinositides
Authors: Li Guiyuan , Rajala Ammaji , Wiechmann Allan F. , Anderson Robert E. , Rajala Raju V. S. 
Published: September 2008

AbstractAkt is a phospholipid‐binding protein and the downstream effector of the phosphoinositide 3‐kinase (PI3K) pathway. Akt has three isoforms: Akt1, Akt2, and Akt3. All of these isoforms are expressed in rod photoreceptor cells, but the individual functions of each isoform are not known. In this study, we found that light induces the activation of Akt1. The membrane binding of Akt1 to rod outer segments (ROS) is insulin receptor (IR)/PI3K‐dependent as demonstrated by reduced binding of Akt1 to ROS membranes of photoreceptor‐specific IR knockout mice. Membrane binding of Akt1 is mediated through its Pleckstrin homology (PH) domain. To determine whether binding of the PH domain of Akt1 to photoreceptor membranes is regulated by light, various green fluorescent protein (GFP)/Akt1‐PH domain fusion proteins were expressed in rod photoreceptors of transgenic Xenopus laevis under the control of the Xenopus opsin promoter. The R25C mutant PH domain of Akt1, which does not bind phosphoinositides, failed to associate with plasma membranes in a light‐dependent manner. This study suggests that light‐dependent generation of phosphoinositides regulates the activation and membrane binding of Akt1 in vivo. Our results also suggest that actin cytoskeletal organization may be regulated through light‐dependent generation of phosphoinositides.
The effect of glibenclamide on acetylcholine and sodium nitroprusside induced vasodilatation in human cutaneous microcirculation
Authors: Hojs Nina , Strucl Martin , Cankar Ksenija 
Published: September 2008

SummaryObjective:  KATP channels have an important regulatory role in resting vascular tone and during hypoxia. Their role in endothelium dependent and independent vasodilatation in human skin microcirculation is less known.Methods:  We monitored the laser‐Doppler (LD) response in 14 healthy male volunteers on the skin of the forearm. In the case of endothelium dependent vasodilatation [acetylcholine (ACh) induced], a saline solution (used as control) or a solution of glibenclamide (KATP channel blocker) were randomly injected each into a distinct measurement site on different forearms followed by the iontophoresis of ACh. In the case of endothelium dependent vasodilatation with the inhibition of prostaglandin production, diclofenac (cyclooxygenase inhibitor) or the combination of diclofenac and glibenclamide were randomly injected each into a distinct measurement site on different forearms followed by the iontophoresis of ACh. In the case of endothelium independent vasodilatation [sodium nitroprusside (SNP) induced], a saline solution or glibenclamide were randomly injected each into a distinct measurement site on different forearms, iontophoresis of SNP followed.Results:  Glibenclamide alone, diclofenac alone or the combination of glibenclamide and diclofenac reduced the LD flux values during rest and after ACh application (P<0·05). The reduction of LD flux in ACh mediated vasodilatation was greatest when using the combination of glibenclamide and diclofenac. In the case of SNP application, there was also a significantly lower LD flux rise for glibenclamide in comparison with the saline solution (P<0·05).Conclusions:  KATP channels play an important role in human cutaneous vasodilatation induced by ACh and SNP.
Validity of Selected AHRQ Patient Safety Indicators Based on VA National Surgical Quality Improvement Program Data
Authors: Romano Patrick S. , Mull Hillary J. , Rivard Peter E. , Zhao Shibei , Henderson William G. , Loveland Susan , Tsilimingras Dennis , Christiansen Cindy L. , Rosen Amy K. 
Published: September 2008

Objectives. To examine the criterion validity of the Agency for Health Care Research and Quality (AHRQ) Patient Safety Indicators (PSIs) using clinical data from the Veterans Health Administration (VA) National Surgical Quality Improvement Program (NSQIP).Data Sources. Fifty five thousand seven hundred and fifty two matched hospitalizations from 2001 VA inpatient surgical discharge data and NSQIP chart‐abstracted data.Study Design. We examined the sensitivities, specificities, positive predictive values (PPVs), and positive likelihood ratios of five surgical PSIs that corresponded to NSQIP adverse events. We created and tested alternative definitions of each PSI.Data Collection. FY01 inpatient discharge data were merged with 2001 NSQIP data abstracted from medical records for major noncardiac surgeries.Principal Findings. Sensitivities were 19–56 percent for original PSI definitions; and 37–63 percent using alternative PSI definitions. PPVs were 22–74 percent and did not improve with modifications. Positive likelihood ratios were 65–524 using original definitions, and 64–744 using alternative definitions. “Postoperative respiratory failure” and “postoperative wound dehiscence” exhibited significant increases in sensitivity after modifications.Conclusions. PSI sensitivities and PPVs were moderate. For three of the five PSIs, AHRQ has incorporated our alternative, higher sensitivity definitions into current PSI algorithms. Further validation should be considered before most of the PSIs evaluated herein are used to publicly compare or reward hospital performance.
Advancing Measurement of Patient Safety Culture
Authors: Ginsburg Liane , Gilin Debra , Tregunno Deborah , Norton Peter G. , Flemons Ward , Fleming Mark 
Published: September 2008

Objective. To examine the psychometric and unit of analysis/strength of culture issues in patient safety culture (PSC) measurement.Data Source. Two cross‐sectional surveys of health care staff in 10 Canadian health care organizations totaling 11,586 respondents.Study Design. A cross‐validation study of a measure of PSC using survey data gathered using the Modified Stanford PSC survey (MSI‐2005 and MSI‐2006); a within‐group agreement analysis of MSI‐2006 data.Extraction Methods. Exploratory factor analyses (EFA) of the MSI‐05 survey data and confirmatory factor analysis (CFA) of the MSI‐06 survey data; Rwg coefficients of homogeneity were calculated for 37 units and six organizations in the MSI‐06 data set to examine within‐group agreement.Principal Findings. The CFA did not yield acceptable levels of fit. EFA and reliability analysis of MSI‐06 data suggest two reliable dimensions of PSC: Organization leadership for safety (α=0.88) and Unit leadership for safety (α=0.81). Within‐group agreement analysis shows stronger within‐unit agreement than within‐organization agreement on assessed PSC dimensions.Conclusions. The field of PSC measurement has not been able to meet strict requirements for sound measurement using conventional approaches of CFA. Additional work is needed to identify and soundly measure key dimensions of PSC. The field would also benefit from further attention to strength of culture/unit of analysis issues.
How Much New Information Is There in Earnings?
Authors: BALL RAY , SHIVAKUMAR LAKSHMANAN 
Published: September 2008

ABSTRACTWe quantify the relative importance of earnings announcements in providing new information to the share market, using the R2 in a regression of securities' calendar‐year returns on their four quarterly earnings‐announcement “window” returns. The R2, which averages approximately 5% to 9%, measures the proportion of total information incorporated in share prices annually that is associated with earnings announcements. We conclude that the average quarterly announcement is associated with approximately 1% to 2% of total annual information, thus providing a modest but not overwhelming amount of incremental information to the market. The results are consistent with the view that the primary economic role of reported earnings is not to provide timely new information to the share market. By inference, that role lies elsewhere, for example, in settling debt and compensation contracts and in disciplining prior information, including more timely managerial disclosures of information originating in the firm's accounting system. The relative informativeness of earnings announcements is a concave function of size. Increased information during earnings‐announcement windows in recent years is due only in part to increased concurrent releases of management forecasts. There is no evidence of abnormal information arrival in the weeks surrounding earnings announcements. Substantial information is released in management forecasts and in analyst forecast revisions prior (but not subsequent) to earnings announcements.