bluuebunny/crossref_metadata_2025 huggingface dataset:
Intracranially Recorded Memory-related Potentials Reveal Higher Posterior than Anterior Hippocampal Involvement in Verbal Encoding and Retrieval
Authors: Ludowig Eva , Trautner Peter , Kurthen Martin , Schaller Carlo , Bien Christian G. , Elger Christian E. , Rosburg Timm
Published: January 2008

The human hippocampus is essential for both encoding and recollection, but it remains controversial whether there is a functionally different involvement of anterior versus posterior parts of the hippocampus in these memory processes. In the present study, we examined encoding and retrieval processes via intrahippocampal recordings in 27 patients with unilateral temporal lobe epilepsy. Multicontact depth electrodes were implanted along the longitudinal axis of the hippocampus as part of the presurgical evaluation. In a continuous word recognition test, subjects had to indicate whether words were new or already presented. Recognized old words, as compared to new words, resulted in a larger P600 component, as well as in a larger late negative component (LNC, 600–900 msec). In addition, subsequently remembered words elicited a larger positivity (400 to 900 msec) than later forgotten words. We found differences concerning the distribution along the hippocampus for the LNC old-new effect, reflecting successful retrieval, as well as for the subsequent memory effect, reflecting successful encoding. Both effects were larger the further posterior an electrode was located in the hippocampus. Findings are suggestive for a predominant posterior hippocampal involvement in both verbal encoding and retrieval.
The Representation of Parts and Wholes in Face-selective Cortex
Authors: Harris Alison , Aguirre Geoffrey Karl
Published: January 2008

Although face perception is often characterized as depending on holistic, rather than part-based, processing, there is behavioral evidence for independent representations of face parts. Recent work has linked “face-selective” regions defined with functional magnetic resonance imaging (fMRI) to holistic processing, but the response of these areas to face parts remains unclear. Here we examine part-based versus holistic processing in “face-selective” visual areas using face stimuli manipulated in binocular disparity to appear either behind or in front of a set of stripes [Nakayama, K., Shimojo, S., & Silverman, G. H. Stereoscopic depth: Its relation to image segmentation, grouping, and the recognition of occluded objects. Perception, 18, 55–68, 1989]. While the first case will be “filled in” by the visual system and perceived holistically, we demonstrate behaviorally that the latter cannot be completed amodally, and thus is perceived as parts. Using these stimuli in fMRI, we found significant responses to both depth manipulations in inferior occipital gyrus and middle fusiform gyrus (MFG) “face-selective” regions, suggesting that neural populations in these areas encode both parts and wholes. In comparison, applying these depth manipulations to control stimuli (alphanumeric characters) elicited much smaller signal changes within face-selective regions, indicating that the part-based representation for faces is separate from that for objects. The combined adaptation data also showed an interaction of depth and familiarity within the right MFG, with greater adaptation in the back (holistic) condition relative to parts for familiar but not unfamiliar faces. Together, these data indicate that face-selective regions of occipito-temporal cortex engage in both part-based and holistic processing. The relative recruitment of such representations may be additionally influenced by external factors such as familiarity.
Event-related Potential Evidence on the Influence of Accentuation in Spoken Discourse Comprehension in Chinese
Authors: Li Xiaoqing , Hagoort Peter , Yang Yufang
Published: January 2008

In an event-related potential experiment with Chinese discourses as material, we investigated how and when accentuation influences spoken discourse comprehension in relation to the different information states of the critical words. These words could either provide new or old information. It was shown that variation of accentuation influenced the amplitude of the N400, with a larger amplitude for accented than for deaccented words. In addition, there was an interaction between accentuation and information state. The N400 amplitude difference between accented and deaccented new information was smaller than that between accented and deaccented old information. The results demonstrate that, during spoken discourse comprehension, listeners rapidly extract the semantic consequences of accentuation in relation to the previous discourse context. Moreover, our results show that the N400 amplitude can be larger for correct (new, accented words) than incorrect (new, deaccented words) information. This, we argue, proves that the N400 does not react to semantic anomaly per se, but rather to semantic integration load, which is higher for new information.
Effects of Right Parietal Transcranial Magnetic Stimulation on Object Identification and Orientation Judgments
Authors: Harris Irina M. , Benito Claire T. , Ruzzoli Manuela , Miniussi Carlo
Published: January 2008

We investigated the role played by the right parietal lobe in object identification and the ability to interpret object orientation, using transcranial magnetic stimulation (TMS) to momentarily interfere with ongoing cortical activity. Short trains of TMS pulses (12 Hz) were applied to a site overlying the right intraparietal sulcus/inferior parietal lobe while subjects performed either object identification tasks (i.e., picture-word verification and categorizing objects as natural or manufactured) or object orientation judgment tasks (i.e., picture-arrow verification and deciding whether an object was rotated clockwise or counterclockwise). Across different tasks, right parietal TMS impaired orientation judgments, but facilitated object identification, compared to TMS applied to a brain vertex control site. These complementary findings demonstrate that the right parietal lobe—a region belonging to the dorsal visual stream—is critical for processing the spatial attributes of objects, but not their identity. The observed improvement in object recognition, however, suggests an indirect role for the right parietal lobe in object recognition. We propose that this involves the creation of a spatial reference frame for the object, which allows interaction with the object and the individuation of specific viewing instances.
Sound Representing Self-Motion in Virtual Environments Enhances Linear Vection
Authors: Väljamäe Aleksander , Larsson Pontus , Västfjäll Daniel , Kleiner Mendel
Published: January 2008

Sound is an important, but often neglected, component for creating a self-motion illusion (vection) in Virtual Reality applications, for example, motion simulators. Apart from auditory motion cues, sound can provide contextual information representing self-motion in a virtual environment. In two experiments we investigated the benefits of hearing an engine sound when presenting auditory (Experiment 1) or auditory-vibrotactile (Experiment 2) virtual environments inducing linear vection. The addition of the engine sound to the auditory scene significantly enhanced subjective ratings of vection intensity in Experiment 1 and vection onset times but not subjective ratings in Experiment 2. Further analysis using individual imagery vividness scores showed that this disparity between vection measures was created by participants with higher kinesthetic imagery. On the other hand, for participants with lower kinesthetic imagery scores, the engine sound enhanced vection sensation in both experiments. A high correlation with participants' kinesthetic imagery vividness scores suggests the influence of a first person perspective in the perception of the engine sound. We hypothesize that self-motion sounds (e.g., the sound of footsteps, engine sound) represent a specific type of acoustic body-centered feedback in virtual environments. Therefore, the results may contribute to a better understanding of the role of self-representation sounds (sonic self-avatars), in virtual and augmented environments.
Immersive Virtual Video Game Play and Presence: Influences on Aggressive Feelings and Behavior
Authors: Persky Susan , Blascovich Jim
Published: January 2008

Immersive virtual environment technology (IVET) allows developers to create simulated environments that can engage users in context relevant behaviors and that can produce relatively intense user experiences for purposes such as entertainment (e.g., video games), phobia desensitization, and training. We predicted that playing a violent video game using an IVET platform would lead to increased presence and aggressive feelings and behavior compared to playing on a less immersive desktop platform. The results of two experiments supported this hypothesis. The data suggest that presence mediated the relationship between playing platform and aggressive feelings but not the relationship between playing platform and aggressive behavior. Finally, we explored the utility of using cardiovascular measures within this research paradigm.
Effects of Stereo Viewing Conditions on Distance Perception in Virtual Environments
Authors: Willemsen Peter , Gooch Amy A. , Thompson William B. , Creem-Regehr Sarah H.
Published: January 2008

Several studies from different research groups investigating perception of absolute, egocentric distances in virtual environments have reported a compression of the intended size of the virtual space. One potential explanation for the compression is that inaccuracies and cue conflicts involving stereo viewing conditions in head mounted displays result in an inaccurate absolute scaling of the virtual world. We manipulate stereo viewing conditions in a head mounted display and show the effects of using both measured and fixed inter-pupilary distances, as well as bi-ocular and monocular viewing of graphics, on absolute distance judgments. Our results indicate that the amount of compression of distance judgments is unaffected by these manipulations. The equivalent performance with stereo, bi-ocular, and monocular viewing suggests that the limitations on the presentation of stereo imagery that are inherent in head mounted displays are likely not the source of distance compression reported in previous virtual environment studies.
Deregulation and the New Leader Agenda: Outcomes and Lessons from Michigan
Authors: Smith BetsAnn
Published: January 2008

Purpose: This research examined whether the removal of certification and other requirements led to larger or more diverse applicant pools for superintendent positions in Michigan. Michigan has not had any degree or certification requirements for educational administrators for many years and provided an empirical test of whether deregulation draws new talent into the field.

Research Design, Methods: The research was designed as a state-level case study employing quantitative and qualitative methods to develop descriptive findings and analytic interpretations.

Data Collection and Analysis: Data on superintendent search processes and applicant pools between 1996 and 2005 were collected. Sources of data included superintendent search files and semistructured interviews with search consultants, private sector recruiters, out-of-field superintendent candidates, professional association leaders, and other actors.

Findings: Removing certification and other requirements did not attract new talent into the field, did not stimulate new search systems, and did not generate interest among schools boards, their constituents, or other external agents. Over the 9-year period studied, superintendent applicant pools in Michigan underwent the same troubling trends in applicant pools and turnover as the nation overall.

Implications: No cavalry of talented executives lurks behind a wall of certification waiting to spread its talents to the nation's districts. Absent significant changes to a web of social, economic, and institutional factors, the likelihood that deregulation policies will affect educational leadership and school organizations is very low.
Mathematics Learning Disabilities in Girls With Fragile X or Turner Syndrome During Late Elementary School
Authors: Murphy Melissa M. , Mazzocco Michèle M. M.
Published: January 2008

The present study focuses on math and related skills among 32 girls with fragile X ( n = 14) or Turner ( n = 18) syndrome during late elementary school. Performance in each syndrome group was assessed relative to Full Scale IQ—matched comparison groups of girls from the general population ( n = 32 and n = 89 for fragile X syndrome and Turner syndrome, respectively). Differences between girls with fragile X and their comparison group emerged on untimed arithmetic calculations, mastery of counting skills, and arithmetic problem verification accuracy. Relative to girls in the comparison group, girls with Turner syndrome did not differ on untimed arithmetic calculations or problem verification accuracy, but they had limited mastery of counting skills and longer response times to complete the problem verification task. Girls with fragile X or Turner syndrome also differed from their respective comparison groups on math-related abilities, including visual—spatial, working memory, and reading skills, and the associations between math and those related skills. Together, these findings support the notion that difficulty with math and related skills among girls with fragile X or Turner syndrome continues into late elementary school and that the profile of math and related skill difficulty distinguishes the two syndrome groups from each other.
Ghrelin Agonist (TZP‐101): Safety, Pharmacokinetics and Pharmacodynamic Evaluation in Healthy Volunteers: A Phase I, First‐in‐Human Study
Authors: Lasseter Kenneth C. , Shaughnessy Laura , Cummings David , Pezzullo John C. , Wargin William , Gagnon Rene , Oliva Jesus , Kosutic Gordana
Published: January 2008

The authors evaluate the human safety, tolerability, pharmacokinetics, and pharmacodynamics of TZP‐101, an agonist of the hGHS‐R1a (ghrelin) receptor. Healthy subjects were randomized to either single‐dose TZP‐101 (20–600 μg/kg) or placebo by 30‐minute intravenous infusion. Subjects underwent continuous cardiac monitoring, 12‐lead electrocardiograms, and assessment for orthostatic hypotension, injection site tolerability, vital signs, and adverse events during the 24‐hour postdose period. Blood and urine samples were collected for pharmacokinetic/pharmacodynamic assessment for 24 hours. Forty‐eight subjects randomly received 1 of 6 TZP‐101 doses or placebo. TZP‐101 was well tolerated, with single episodes each of headache, lower abdominal pain, diarrhea, and dizziness. At the highest dose, 2 subjects experienced bradycardia. All events were self‐limited. Mean arterial blood pressure and heart rate decreased from baseline approximately 45 to 60 minutes after infusion start at higher doses. No other significant changes were observed. Pharmacokinetic analysis revealed less than dose‐proportional behavior of drug with low clearance (≅7 mL/h/kg), small volume of distribution (≅114 mL/kg), and half‐life values of ≅13 hours, which were independent of dose. Pharmacodynamic analyses suggested TZP‐101, at doses as low as 40 μg/kg, expressed activity at the receptor. TZP‐101 displayed a promising pharmacokinetic, pharmacodynamic, and safety profile for use in gastrointestinal motility disorders.
Safety, Tolerability, and Single‐ and Multiple‐Dose Pharmacokinetics of Piperaquine Phosphate in Healthy Subjects
Authors: Ahmed Tausif , Sharma Pradeep , Gautam Anirudh , Varshney Brijesh , Kothari Monica , Ganguly Sanjeev , Moehrle Joerg J. , Paliwal Jyoti , Saha Nilanjan , Batra Vijay
Published: January 2008

Piperaquine phosphate is an orally active bisquinolone antimalarial drug that has been used for the past 3 decades. The authors report the safety, tolerability, and pharmacokinetics of piperaquine from a classical controlled phase I study. It was a double‐blind, randomized, parallel‐group, placebo‐controlled, and single‐ and multiple‐dose study. During the rising single‐dose study, single ascending oral doses of 500, 750, 1000, 1250, and 1500 mg of piperaquine phosphate were administered, whereas in rising multiple‐dose study, once‐daily ascending oral doses of 500, 750, 1000, and 1500 mg were administered for 3 consecutive days. Pharmacokinetic analysis for both the rising single‐ and multiple‐dose studies was done using the noncompartmental approach. The mean apparent terminal half‐life ranged from 11 to 23 days. Increase in exposure was less than dose proportional and linear. Piperaquine concentrations were measurable up to 60 days postdose. Multiple peaks were observed in the plasma piperaquine concentration—time profiles and exhibited 3‐ to 7‐fold accumulation following multiple dosing. Piperaquine was well tolerated following single and multiple doses.
Sex, Race, and Smoking Impact Olanzapine Exposure
Authors: Bigos Kristin L. , Pollock Bruce G. , Coley Kim C. , Miller Del D. , Marder Stephen R. , Aravagiri Manickam , Kirshner Margaret A. , Schneider Lon S. , Bies Robert R.
Published: January 2008

Response to antipsychotics is highly variable, which may be due in part to differences in drug exposure. The goal of this study was to evaluate the magnitude and variability of concentration exposure of olanzapine. Patients with Alzheimer's disease (n = 117) and schizophrenia (n = 406) were treated with olanzapine as part of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE). Combined, these patients (n = 523) provided 1527 plasma samples for determination of olanzapine concentrations. Nonlinear mixed‐effects modeling was used to determine the population pharmacokinetics of olanzapine, and patient‐specific covariates were evaluated as potential contributors to variability in drug exposure. The population mean olanzapine clearance and volume of distribution were 16.1 L/h and 2150 L, respectively. Elimination of olanzapine varied nearly 10‐fold (range, 6.66–67.96 L/h). Smoking status, sex, and race accounted for 26%, 12%, and 7% of the variability, respectively (P < .0001). Smokers cleared olanzapine 55% faster than non/past smokers (P < .0001). Men cleared olanzapine 38% faster than women (P < .0001). Patients who identified themselves as black or African American cleared olanzapine 26% faster than other races (P < .0001). Differences in olanzapine exposure due to sex, race, and smoking may account for some of the variability in response to olanzapine.
Performance Characteristics for Some Typical QT Study Designs Under the ICH E‐14 Guidance
Authors: Hutmacher Matthew M. , Chapel Sunny , Agin Marilyn A. , Fleishaker Joseph C. , Lalonde Richard L.
Published: January 2008

The International Conference on Harmonization (ICH) guidance for clinical evaluation of QT prolongation (E14) affected drug development by advocating that a thorough QT study (TQT) be conducted during development to assess the QT prolongation liability of a compound. The ICH E14 Statistics Group shortly thereafter recommended that a noninferiority intersection‐union test (IUT) be used to exclude a clinically worrisome QT prolongation. Recent analyses have indicated that the IUT might be overly conservative with respect to excluding QT prolongation. This report assesses the IUT false positive rate for 4 recently conducted TQT trials using simple simulation experiments. Positive TQT study rates ranged from negligible to nearly 60% depending on study design, sample size, and patient status, despite no drug effect. Addition of clinically nonmeaningful QT prolongations (up to 5 milliseconds) increased the positive study rate to 80% for 1 particular study design. Ultimately, these results reveal significant limitations of the IUT with respect to excluding an effect and study interpretation for certain trial designs.
Child and Adolescent Psychopathy
Authors: Salekin Randall T. , Lochman John E.
Published: January 2008

This current article introduces the special issue on child and adolescent psychopathy and the search for protective factors. Although there has been considerable research conducted on psychopathy at the adult level and a surge of research attempting to extend the concept to children and adolescents in the past decade, few studies have attempted to examine factors that might moderate or protect against the development of psychopathy. This special issue focuses on topics relevant to examining potential protective factors within a developmental psychopathology framework. Articles in the special issue are longitudinal and thus allow for the examination of protective factors as they are evidenced in real time. They focus on genetics, peer relations, parental factors, and internalizing and externalizing symptoms. These studies provide a foundation for examining protective factors and provide the groundwork for future research in this area.
Correlates of Substance Use in Relation to Sexual Behavior in Black Gay and Bisexual Men: Implications for HIV Prevention
Authors: Wilton Leo
Published: January 2008

Since the onset of the AIDS epidemic, Black gay and bisexual men have been at a substantial risk for acquiring HIV. Substance use has been identified as a significant risk factor for engaging in HIV sexual risk behavior. The purpose of this formative research investigation was to examine substance use in relation to sexual behavior through differentiating users versus nonusers of alcohol and recreational drugs before or during sex in a community-based sample of 481 Black gay and bisexual men in the New York metropolitan area. Binary logistic regression results demonstrated that alcohol use before or during sex was predictive of having a primary sex partner, casual sex partner, higher income, previous sexually transmitted infection testing, and a higher number of male sex partners. Recreational drug use before or during sex was predictive of having an HIV positive status, casual sex partner, unprotected anal intercourse with a male sex partner, and being younger. These findings present significant formative implications for the influence of substance use in relation to HIV sexual risk behavior in Black gay and bisexual men.
Class, Race, and the Face: Social Context Modulates the Cross-Race Effect in Face Recognition
Authors: Shriver Edwin R. , Young Steven G. , Hugenberg Kurt , Bernstein Michael J. , Lanter Jason R.
Published: January 2008

The current research investigates the hypothesis that the well-established cross-race effect (CRE; better recognition for same-race than for cross-race faces) is due to social-cognitive mechanisms rather than to differential perceptual expertise with same-race and cross-race faces. Across three experiments, the social context in which faces are presented has a direct influence on the CRE. In the first two experiments, middle-class White perceivers show superior recognition for same-race White faces presented in wealthy but not in impoverished contexts. The second experiment indicates this effect is due to the tendency to categorize White faces in impoverished contexts as outgroup members (e.g., “poor Whites”). In the third experiment, this effect is replicated using different ingroup and outgroup categorizations (university affiliation), with ingroup White faces being recognized better than outgroup White faces. In line with a social-cognitive model of the CRE, context had no influence on recognition for cross-race Black faces across the three experiments.
Comparative analysis of oxygen uptake in elderly subjects performing two walk tests: the six-minute walk test and the 200-m fast walk test
Authors: Gremeaux Vincent , Iskandar Marwan , Kervio Gaëlle , Deley Gaëlle , Pérénnou Dominic , Casillas Jean-Marie
Published: January 2008

Objective: A novel walk test is proposed to assess the ability of elderly subjects to sustain a submaximal effort in ecological surroundings. Vo2 uptake during this test was compared with that of a six-minute walk test and maximal exercise test.

Design: Descriptive laboratory study.

Setting: Rehabilitation department, Dijon University Hospital.

Subjects: Thirty-one subjects, aged from 70 to 85 years, free from any chronic disease.

Intervention: Three tests to assess physical capacities: the 200-m fast walk test (200 mFWT), the six-minute walk test (6 MWT) at self-paced speed, and one maximal cardiorespiratory exercise test on an ergocycle.

Main measures: Distance walked on the 6 MWT, time to perform the 200 mFWT. Heart rate (HR) and oxygen uptake (Vo2) were measured for each test.

Results: All subjects successfully completed the two walk tests without any complaints. They walked more quickly during the 200 mFWT than during the 6 MWT (mean (SD) speed respectively 1.60 (0.17) versus 1.23 (0.16) m/s, P<0.001). Compared with the maximal exercise test, the relative intensity was much higher during the 200 mFWT than during the 6 MWT (mean (SD) Vo2 uptake 86.8 (8.9)% versus 67.4 (10.7)% of peak Vo2, mean (SD) HR 89.9 (9.4) versus 76.2 (0.8)% of peak HR; P<0.001).

Conclusion: In healthy elderly subjects, the 200 mFWT requires a more sustained effort than the 6 MWT. This test is simple, ecological and well tolerated. In addition to the 6 MWT, the 200 mFWT could be a useful tool to build up and evaluate training or rehabilitation programmes, especially when interval training is planned
Effects of vitamin E supplementation on plasma membrane permeabilization and fluidization induced by chlorpromazine in the rat brain
Authors: Maruoka Nobuyuki , Murata Tetsuhito , Omata Naoto , Takashima Yasuhiro , Fujibayashi Yasuhisa , Wada Yuji
Published: January 2008

Neurotransmitter receptors play a key role in most research on antipsychotic drugs, but little is known about the effects of these drugs on the plasma membrane in the central nervous system. Therefore, we investigated whether chlorpromazine (CPZ), a typical phenothiazine antipsychotic drug, affects the plasma membrane integrity in the rat brain, and if so, whether these membrane alterations can be prevented by dietary supplementation with vitamin E, which has been shown to be an antioxidant and also a membrane-stabilizer. Leakage of [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG)-6-phosphate from rat striatal slices and decrease in 1,6-diphenyl-1,3,5-hexatriene fluorescence anisotropy were used as indexes for plasma membrane permeabilization and fluidization, respectively. CPZ induced leakage of [18F]FDG-6-phosphate from striatal slices, and the leakage was delayed in the vitamin E-supplemented group compared to that in the normal diet group. The decrease in plasma membrane anisotropy induced by CPZ was significantly attenuated by vitamin E supplementation. Chronic treatment with α-phenyl-N-tert-butyl nitrone, a free radical scavenger, had no effect on CPZ-induced plasma membrane permeabilization, and the treatment with CPZ did not induce lipid peroxidation. CPZ can reduce plasma membrane integrity in the brain, and this reduction can be prevented by vitamin E via its membrane-stabilizing properties, not via its antioxidant activity.
Adequacy of continuation and maintenance treatments for major depression in Japan
Authors: Fujita Akiko , Azuma Hideki , Kitamura Toshinori , Takahashi Kiyohisa , Akechi Tatsuo , Furukawa Toshi A.
Published: January 2008

Guidelines for treating depression often recommend continuing antidepressants at least for 6 months after remission. Whether this recommendation is implemented in daily practices represents a serious concern. We aimed to examine adequacy of continuation and maintenance treatment in Japan. A naturalistic prospective follow-up study with mood disorders was undertaken in 23 psychiatric departments from all over Japan. A total of 95 patients diagnosed with major depression were followed up every month until treatment termination and every 6 months thereafter. In this study, the cohort received 45.1 (SD = 64.7) mg of imipramine or equivalent per day during continuation phase, and about 74% were prescribed inadequate doses, i.e. less than 75 mg/day. At maintenance phase immediately before relapse, average dosage was 42.0 (SD = 74.7) mg/day and 83% were prescribed inadequate doses. There is gross under-treatment of depression during continuation and maintenance phases in Japan.
Appetitive overshadowing is disrupted by systemic amphetamine but not by electrolytic lesions to the nucleus accumbens shell
Authors: Horsley RR , Moran PM , Cassaday HJ
Published: January 2008

There is evidence that the indirect dopamine (DA) agonist amphetamine (AMP) can disrupt selective learning in an aversive overshadowing task, consistent with a role for the DA system in this form of salience manipulation. In the following experiments we assessed in the male Wistar rat: (1) whether amphetamine disruption of overshadowing extends to an appetitively motivated overshadowing task; and (2) whether selective electrolytic lesions to the n.acc (shell versus core subfields) disrupt appetitively motivated overshadowing. The experiments used sucrose reward pellets as the unconditioned stimulus (UCS). In each case, a conditioned stimulus (CS, light) was either conditioned alone or in compound together with a more intense CS (noise or tone). The presence of overshadowing was demonstrated as reduced conditioning to the light when it had been previously conditioned in compound compared to when it had been conditioned alone.

It was predicted that AMP and lesions to the n.acc shell would disrupt overshadowing. AMP was found to abolish overshadowing at 0.5 mg/kg, but not at 1 mg/kg. Contrary to prediction, the shell lesioned animals did not differ from shams. The results of Experiment 1 add to the evidence that the DA system can moderate salience processing of weaker predictors, also in cases where CS salience is manipulated directly via the physical intensities of the stimuli, as here. However, in terms of the brain structures involved, Experiment 2 suggests that, overshadowing is moderated by projections of the DA system without n.acc.
Ziprasidone and aripiprazole attenuate olanzapine-induced hyperphagia in rats
Authors: Snigdha S. , Thumbi C. , Reynolds GP , Neill JC
Published: January 2008

Weight gain induced by some second-generation anti—psychotics such as olanzapine has emerged as a most debilitating side-effect. This study investigates whether co-administration with either ziprasidone or aripiprazole, which have little propensity to induce weight gain, can attenuate the hyperphagic effect of olanzapine. Female hooded-Lister rats ( n = 8 per group) were treated acutely with either vehicle, olanzapine (1 mg/kg), ziprasidone (1 mg/kg), aripiprazole (2 mg/kg) or olanzapine in combination with ziprasidone or aripiprazole and placed in automated locomotor activity (LMA) boxes with preweighed palatable mash. Food intake and LMA were measured for 60 min postdrug treatment. All olanzapine-treated groups demonstrated significant increases in food intake ( P < 0.001). This effect was attenuated following co-administration of olanzapine with either ziprasidone or aripiprazole ( P < 0.001), neither of which affected food intake alone. The lack of hyperphagia induced by aripiprazole and ziprasidone may reflect an inherent pharmacological mechanism preventing weight gain.
Differential expression of IEG mRNA in rat brain following acute treatment with clozapine or haloperidol: a semi-quantitative RT—PCR study
Authors: Robbins MJ , Critchlow HM , Lloyd A. , Cilia J. , Clarke JD , Bond B. , Jones DNC , Maycox PR
Published: January 2008

Antipsychotic drugs have been shown to modulate immediate early gene (IEG) expression in rat brain regions that are associated with schizophrenia, which may be directly linked to their immediate therapeutic benefit. In this study, we analysed the expression profile of a series of IEGs (c-fos, c-jun, fra-1, Krox-20, Krox-24, arc, sgk-1, BDNF and NARP) in six rat brain regions (prefrontal cortex, hippocampus, striatum, nucleus accumbens, thalamus and cerebellum). Rats ( n = 5) were administered either clozapine (20 mg/kg i.p.), haloperidol (1 mg/kg i.p.) or the appropriate vehicle with pre-treatment times of 1, 6 and 24 h. IEG expression was analysed in these regions by Taqman RT—PCR. The spatial and temporal profile of IEG induction following antipsychotic drug treatment correlates with regions associated with the efficacy and side effect profile of each drug. In particular, sgk-1 expression levels after antipsychotic drug treatment may have predictive value when investigating the profile of a novel antipsychotic drug.
The effect of rate of antidepressant tapering on the incidence of discontinuation symptoms: a randomised study
Authors: Tint Aung , Haddad Peter M , Anderson Ian M
Published: January 2008

Twenty eight patients treated with selective serotonin reuptake inhibitors /venlafaxine were randomized to a three-day (short) or 14-day (longer) anti—depressant taper and openly assessed after a five to seven day drug-free washout, and again after seven days treatment with a new anti—depressant of the treating clinician's choice. A 'discontinuation syndrome' ( ≥ 3 new symptoms on the Discontinuation Emergent Signs and Symptoms checklist) occurred in 46% of patients with a similar frequency in those with short (7/15) versus longer (6/13) taper. Patients initially on short half-life anti—depressants had significantly greater increases in discontinuation and depressive symptoms than those stopping fluoxetine. Four patients, all on paroxetine, developed emergent suicidal ideation after taper. These results support the importance of half-life in determining discontinuation symptoms and suggest that there is little advantage to a two-week taper over a three-day taper when switching antidepressants. Antidepressant discontinuation in depressed patients can be associated with worsening depression and increased suicidality.
Modulation of celecoxib- and streptozotocin-induced experimental dementia of Alzheimer's disease by pitavastatin and donepezil
Authors: Sharma Bhupesh , Singh Nirmal , Singh Manjeet
Published: January 2008

Present study was designed to investigate modulation of experimental dementia by Pitavastatin and donepezil. Learning and memory of the swiss albino mice were studied on Morris water-maze. Celecoxib orally (p.o.)/Streptozotocin (STZ) intracerebroventricular administrations were used to induce experimental dementia. Brain acetyl cholinesterase activity was measured by EllMann's method to assess cholinergic activity of the brain. Brain thio barbituric acid reactive species (TBARS) levels and reduced glutathione (GSH) levels were measured by Ohokawa's and Beutler's method respectively, to assess total oxidative stress in brain. Total serum cholesterol level was measured by Allain's method. Celecoxib/STZ treatments produced a significant loss of learning and memory. Pitavastatin/Donepezil successfully attenuated this Celecoxib/STZ induced dementia. Higher levels of brain acetyl-cholinesterase (AChE) activity, TBARS and lower level of GSH were observed in Celecoxib/STZ treated animals, which were significantly attenuated by Donepezil. Pitavastatin also attenuated the Celecoxib/STZ induced high levels of TBARS & low levels of GSH without effecting AChE activity and total serum cholesterol levels. Celecoxib induced dementia noted in the present study may be attributed to its stimulatory effect on amyloid beta-42, brain AChE activity, and oxidative stress. Sub-diabetogenic STZ induced memory deficits closely related to Alzheimer's disease. Reversal of Celecoxib/STZ induced memory deficits by Pitavastatin may be due to its antioxidative, anti beta amyloid aggregatory property, and by Donepezil, due to its anticholinesterase and neuroprotective actions.
P3b versus P3a: an event-related potential investigation of the glucose facilitation effect
Authors: Riby LM , Sünram-Lea SI , Graham C. , Foster JK , Cooper T. , Moodie C. , Gunn VP
Published: January 2008

The ingestion of a glucose containing drink has been shown to improve performance on a variety of cognitive tasks. There is debate, however, as to whether glucose especially benefits hippocampal memory functioning or whether it has a more global effect on attentional systems. The present study used event related potential methodology (ERPs) to investigate further glucose-mediated cognitive processes. Each participant acted as his/her own control in a repeated measures design, receiving one of two possible treatments (25g glucose vs. placebo) in a counterbalanced order. After a two hour fasting period participants completed a visual three-stimulus oddball task. This paradigm involves an individual detecting an infrequent target stimulus randomly embedded in a train of repetitive background or standard stimuli. Detection of the target results in a large P3b ERP component (memory updating effect). The infrequent presentation of a novel and irrelevant stimulus, randomly interspersed with the target and standard stimuli, generates a P3a response (orientation of attention effect). These components were used as markers to establish whether the glucose enhancement effect was restricted to the neuro-cognitive processes related to memory. Consistent with behavioural work, glucose moderated the magnitude and latency of the P3b ERP component. However, glucose also interacted with attentional systems (P3a and an earlier P2), although this effect was non-significant. This work converges with recent fMRI findings indicating the sensitivity of the medial-temporal lobes and the pre-frontal cortex to glucose administration.
Similar discontinuation symptoms for withdrawal from medium-dose paroxetine and venlafaxine after nine years in the same patient
Authors: Kotzalidis GD , de Pisa E. , Patrizi B. , Savoja V. , Ruberto G. , Girardi P.
Published: January 2008

A woman who had developed a discontinuation syndrome nine years ago with paroxetine tapered from 10 to 5 mg/day represented the same syndrome recently when she occasionally missed her 75 mg q 12 h venlafaxine doses. The symptoms, comprising agitation, numbness, pricking sensations, sweating, difficulty concentrating, weakness, derealisation and perceived xerophthalmia, immediately subside upon drug dose reinstitution. The patient had used cannabis irregularly before the onset of pauci-symptomatic panic attacks, but none of her panic symptoms were present in her withdrawal symptomatology. Some symptoms waxed and waned during the withdrawal period. The syndrome is compatible with both hyper- and hypoactivity of the central serotonergic system.
Systemic mazindol reduces food intake in rats via suppression of meal size and meal number
Authors: Wellman PJ
Published: January 2008

The aim of the present study was to determine the impact of the appetite suppressant mazindol on meal pattern in rats. Meal patterns were monitored in adult male rats after mazindol dosing during the first three hours of the dark cycle using automated feeding chambers (BioDAQ). Mazindol (0, 0.25, 1.25 and 2.5 mg/kg, IP) produced a dose-dependent hypophagia and hypodipsia. Meal size and meal number were significantly suppressed by mazindol. The meal pattern findings indicate that mazindol inhibits eating in the rat via a suppression of both meal size and meal number.
Effects of chronic infusion of neurotensin and a neurotensin NT1 selective analogue PD149163 on amphetamine-induced hyperlocomotion
Authors: Norman C. , Beckett Srg , Spicer CH , Ashton D. , Langlois X. , Bennett GW
Published: January 2008

Neurotensin (NT) has been proposed as an endogenous antipsychotic based in part on the similarity in behavioural effects to antipsychotic drugs, for example, attenuation of both amphetamine-induced hyperlocomotion (AH) and amphetamine disrupted pre-pulse inhibition in the rat. However, there is some evidence that repeated administration of NT or an analogue produces behavioural tolerance to such effects. The present experiments sought to confirm and extend these findings by testing the effects on AH of 7 days central administration of NT and the NT1selective analogue PD 149163 and the effects of 21 days central administration of NT. NT and PD149163 continuously administered for 7 days produced no effect on AH (in contrast to attenuation with a single injection here and previously reported), whereas 21 days of NT administration potentiated AH. Together, these studies report that the effects of NT or a NT analogue on AH depends on the duration of administration of peptide. The results are discussed in comparison with the reported antipsychotic properties of acute administration of NT and possible mechanisms involving NT1receptors.
Methylphenidate and nicotine focus responding to an informative discrete CS over successive sessions of appetitive conditioning
Authors: Cassaday HJ , Finger BC , Horsley RR
Published: January 2008

Methylphenidate (MP) and nicotine would be expected to improve associative learning, though previous evidence suggests that they should reduce the selectivity with which associations are formed. Here we tested their effects on learning the association between a conditioned stimulus (CS) and food (unconditioned stimulus, UCS) in male Wistar rats. The UCS was delivered immediately (0s) following CS offset or after a 10s trace. In addition to the measures of discrete CS conditioning, contextual and trace responding was measured in the inter-trial- and the inter-stimulus-interval, respectively. In all cases, conditioning was measured as nose poking for food. Both MP and nicotine improved the acquisition of discrete cue conditioning. Acquisition was accelerated (compared to saline) under 5 but not 1 mg/kg MP and 0.6, but not 0.4 mg/kg nicotine. In each case, this effect was observed in 0s but not 10s conditioned groups. For comparison, some earlier published data obtained following the same procedure with D-amphetamine were re-analysed in the same way. Amphetamine similarly improved conditioning in the 0s group, in this case at 0.5, but not 1.5 mg/kg. Thus three different dopamine agonists increased the ability to focus responding to CS presentations over successive sessions of appetitive acquisition.
South African-ness Among Adolescents
Authors: Norris Shane A. , Roeser Robert W. , Richter Linda M. , Lewin Nina , Ginsburg Carren , Fleetwood Stella A. , Taole Elizabeth , van der Wolf Kees
Published: January 2008

The authors assessed the emergence of a South African identity among Black, Colored (mixed ancestral origin), White (predominantly English speaking), and Indian adolescents participating in a birth cohort study called “Birth to Twenty” in Johannesburg, South Africa. They examined young people's certainty of their self-categorization as South African; the centrality of their personal, racial, linguistic, and South African identities in their self-definition; and their perceptions of South African life and society today. These results reflect a historical opportunity for full citizenship and national enfranchisement that the end of apartheid heralded for Black and Colored individuals. Black and Colored youth tend to be more certain about their South African-ness, have a more collective identity, and have a more positive perception around South Africa. In contrast, White and Indian youth are less certain about their South African-ness, have a more individualistic identity, and have a less positive perception about South Africa today.
Complications of Anterior Cruciate Ligament Reconstruction with Bone-Patellar Tendon-Bone Constructs
Authors: Busam Matthew L. , Provencher Matthew T. , Bach Bernard R.
Published: January 2008

Rupture of the anterior cruciate ligament is a common injury. Correct diagnosis and patient selection, along with proper surgical technique, with careful attention to anatomic graft placement, followed by attention to proper rehabilitation, leads to predictably good to excellent results. This article reviews the recognition and avoidance of complications associated with bone–patellar tendon–bone contructs of anterior cruciate ligament reconstruction.
Making (In)Visible
Authors: Hentschel Christine
Published: January 2008

This article focuses on the new plurality of social and spatial categorizing in everyday policing and watching in urban South Africa. It is argued that the pluralization of control produces new forms of social sorting that are neither reducible to after-pains of racial apartheid nor to an often-claimed new economic segregation. By investigating different, not only state-driven, modes of observing public space, mapping hotspots, controlling bars, or identifying “intruders,” it is shown that “the will-to-see” goes hand-in-hand with a tendency to force from view. Outlined is how the interaction of these opposing logics of making visible and making invisible in the everyday policing of “crime and grime” in the coastal town of Durban can provide insights into practices of inclusion in the new South Africa.
Comparison of Modeling Approaches for Full-scale Nonlinear Viscous Dampers
Authors: Yun H.-B. , Tasbighoo F. , Masri S.F. , Caffrey J.P. , Wolfe R.W. , Makris N. , Black C.
Published: January 2008

A study is presented comparing several identification approaches, both parametric and nonparametric, for developing reduced-order nonlinear models of full-scale nonlinear viscous dampers commonly used with large flexible bridges. Such models are useful for incorporation into large-scale computational models, as well as for use as part of structural health monitoring studies based on vibration signature analysis. The paper reports the analysis results from a large collection of experimental tests on a 1112 kN (250 kip) orifice viscous damper under a wide range of frequency and amplitude oscillations. A simplified parametric design model is used in the parametric phase, as well as two different nonparametric methods: the Restoring Force Method, and artificial neural networks. The variations of model parameters with the excitation and response characteristics are investigated, and the relative accuracy and fidelity of the modeling approaches are compared and evaluated.
Dynamical Integrity and Control of Nonlinear Mechanical Oscillators
Authors: Rega Giuseppe , Lenci Stefano
Published: January 2008

The dynamical integrity of nonlinear mechanical oscillators is analyzed in a systematic way extending a previous authors' work. The definition of the safe basin, which is a crucial point that entails choosing what is dynamically acceptable, is critically reviewed. Two different integrity measures are used to quantify the magnitude of the safe basin. When drawn as functions of a varying parameter, they give the so-called erosion profiles, which are the key tool for studying the variation of dynamical integrity. The main focus is on the practically most interesting cases in which the parameter is the excitation amplitude and the integrity reduces as it increases. With the aim of reducing erosion, namely of shifting the erosion profiles toward larger excitation amplitudes, a control method is then applied. It is based on eliminating the homo/heteroclinic bifurcation of the hilltop saddle, which is the triggering event for the considered erosions, by optimally choosing the shape of the periodic excitation. The erosion curves of four different mechanical oscillators, chosen with the aim of covering some main mechanical, dynamical and control features, are numerically constructed and systematically compared with each other. It is found that the control is always able to shift the erosion profiles, although to different extents. Furthermore, its effectiveness may extend above, sometimes well above, the theoretical predictions. Several supplementary specific issues of dynamics and control interest are discussed in detail.