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Present Experiment (present + experiment)
Selected AbstractsHippocampus modulates the behaviorally-sensitizing effects of nicotine in a rat model of novelty-seeking: Potential role for mossy fibersHIPPOCAMPUS, Issue 10 2007Amrinder S. Bhatti Abstract Present experiments investigate interactions between a rat model of the novelty-seeking phenotype and psychomotor sensitization to nicotine (NIC) in adolescence, and the potential role of hippocampal mossy fibers in mediating the behaviorally-sensitizing effects of NIC. Outbred rats were phenotype-screened as high-responders (HR; locomotor reactivity to novelty score ranking in the upper third of the population) or low-responders (LR; locomotor reactivity to novelty score ranking in the lower third of the population). In Experiment 1, both phenotypes were trained with four NIC injections (at 3-d intervals on postnatal days 33,44), and lidocaine microinfusion was used to temporarily inactivate the hippocampal hilus at each NIC injection. Systemic saline and microinjection of artificial cerebral spinal fluid (CSF) were used as controls. During NIC training, lidocaine inactivation caused augmented locomotor response to NIC in HRs compared to LRs irrespective of injection days. Following 1 week of abstinence, all animals were challenged with a low dose of NIC. During challenge, previously NIC/CSF trained LRs and HRs were divided into two; one half receiving lidocaine inactivation of the hippocampal hilus and the other half receiving CSF control microinjection. Only HRs showed behavioral sensitization to the challenge dose of NIC, which was enhanced with lidocaine inactivation. In Experiment 2, a single NIC exposure was found sufficient to induce sensitization to the challenge dose of NIC in HRs, and concurrently an enlarged supra-pyramidal mossy fiber (SP-MF) terminal field. The increase in the SP-MF volume in HRs was greater with repeated NIC training. In both single and repeated NIC training cases, a significant positive morphobehavioral correlation was observed between challenge NIC-induced locomotion and the SP-MF terminal field volume. These findings suggest that the HR hippocampal mossy fibers are vulnerable to neuroadaptive alterations induced by NIC, which may be a substrate for the observed behavioral vulnerability to NIC. © 2007 Wiley-Liss, Inc. [source] Pair Duets in the Yellow-Naped Amazon (Psittaciformes: Amazona auropalliata): Responses to Playbacks of Different DialectsETHOLOGY, Issue 2 2001Timothy F. Wright Yellow-naped amazons, Amazona auropalliata, have regional dialects in which several functional classes of vocalization, including contact calls and pair duets, change their acoustic structure at the same geographic boundaries. Here we examine the responses of 11 pairs of yellow-naped amazons to playbacks of duets from other pairs nesting near the same roost, other roosts within the same dialect, and roosts in foreign dialect areas. Overall, pairs responded more strongly to duets from their own dialect than to those of the foreign dialect. Pairs responded to both treatments from their own dialect (local same dialect and distant same dialect) with movement towards the broadcasting loudspeaker and more rarely with squeals, a vocalization typically observed only in the context of aggressive chases. These aggressive responses were never observed during playbacks of the foreign dialect treatment or congeneric controls. There were no differences among treatments in the incidence of contact calls or pair duets. A similar pattern of stronger aggressive responses to local than to foreign dialects has been found in a wide range of oscine songbirds. The results of the present experiment suggest that a general function may underlie this behavioral response both in oscines and in other bird taxa with vocal learning. [source] Experimental study of the flow boiling heat transfer enhancement and pressure drop due to the bubble behavior restricted by a screen sheetHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 4 2003Katsuhiko Kadoguchi Abstract A unique method previously proposed by the authors was applied to the heat transfer augmentation in the flow boiling field. In this method a screen sheet was placed on the horizontal heated surface where bubble nucleation occurred. Generated vapor bubbles were trapped between the screen and the wall, became flat, and moved along the surface. This restricted bubble behavior caused the heat transfer enhancement. Three types of screen sheet were tested in the present experiment and the effect of the screen on the heat transfer and two-phase flow characteristics was investigated. In two of these cases, the screen was displaced upward by the bubble nucleation. Compared with the ordinary flow boiling case, heat transfer was enhanced by a factor of 1.2 to 6 within the present experimental range. Using a simple flow model, it was made clear that the effect of the height of the displaced screen was important in evaluating the increase in pressure drop. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(4): 319,329, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10094 [source] Involuntary, unreinforced (pure) spatial learning is impaired by fimbria-fornix but not by dorsal hippocampus lesionsHIPPOCAMPUS, Issue 3 2003Norman M. White Abstract Pure spatial learning occurs when rats acquire information about an environment while exploring it in the absence of reinforcers. We previously reported that voluntary, unreinforced exploration of a radial maze retards subsequent reinforced conditioned cue preference (CCP) learning in the same maze. In the present experiment, we examined the effects of involuntary, unreinforced pre-exposure to a radial maze. During pre-exposure, rats were moved by an experimenter between the ends of two arms of a radial maze five times in 30 min. This form of pre-exposure retarded CCP learning, whereas rats that were not pre-exposed and rats that were pre-exposed to a maze in a different room displayed normal CCP learning. These findings suggest that some information specific to the maze environment was acquired during involuntary unreinforced pre-exposure to it. In experiment 2, the retardation of reinforced CCP learning by involuntary unreinforced pre-exposure was eliminated by fimbria-fornix lesions made before pre-exposure but was unaffected by fimbria-fornix lesions made after pre-exposure but before training. Large neurotoxic lesions of the dorsal hippocampus made before pre-exposure had no effect on the retardation of CCP learning, but the rats with these lesions were impaired on a standard test of reinforced spatial learning in a water maze. The lesion effects in experiment 2 are similar to those previously reported for voluntary exploration and suggest that pure spatial learning may occur during both voluntary exploration of and involuntary exposure to an environment in the absence of reinforcers. Pure spatial learning can apparently occur with exposure to two different locations within an environment, but the rats do not have to move between the locations voluntarily. An intact fimbria-fornix is required for acquisition but not expression of this form of learning. The hippocampus is not involved in this form of learning. Hippocampus 2003;13:324,333. © 2003 Wiley-Liss, Inc. [source] SANS polarization analysis with nuclear spin-polarized 3HeJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2000T.R. Gentile A neutron spin filter based on transmission through nuclear-spin-polarized 3He gas has been applied to polarization analysis of small angle neutron scattering (SANS). Such spin filters, which are based on the large spin dependence of the absorption of neutrons by 3He, make SANS polarization analysis possible because of their large angular acceptance. In the present experiment, a 3He-based analyzer was employed to separate nuclear scattering into its coherent and spin-incoherent components. Polarized 3He analyzers were prepared by two different optical pumping methods and installed on the NG3 SANS instrument at the NIST Center for Neutron Research (NCNR). Measurements were taken on cellophane tape and silica gel, for which the scattering is almost completely incoherent and coherent, respectively, and on a combined sample. For the combined sample, separation of the coherent part from the incoherent part was successfully demonstrated using polarization analysis. [source] Bacterial synthesis of poly(hydroxybutyrate- co-hydroxyvalerate) using carbohydrate-rich mahua (Madhuca sp.) flowersJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007P.K. Anil Kumar Abstract Aims:, The objective of the present work was to utilize an unrefined natural substrate namely mahua (Madhuca sp.) flowers, as a carbon source for the production of bacterial polyhydroxyalkanoate (PHA) copolymer by Bacillus sp-256. Methods and Results:, In the present work, three bacterial strains were tested for PHA production on mahua flower extract (to impart 20 g l,1 sugar) amongst which, Bacillus sp-256 produced higher concentration of PHA in its biomass (51%) compared with Rhizobium meliloti (31%) or Sphingomonas sp (22%). Biosynthesis of poly(hydroxybutyrate-co-hydroxyvalerate) , P(HB-co-HV) , of 90 : 10 mol% by Bacillus sp-256 was observed by gas chromatographic analysis of the polymer. Major component of the flower is sugars (57% on dry weight basis) and additionally it also contains proteins, vitamins, organic acids and essential oils. The bacterium utilized malic acid present in the substrate as a co-carbon source for the copolymer production. The flowers could be used in the form of aqueous extract or as whole flowers. PHA content of biomass (%) and yield (g l,1) in a 3·0-l stirred tank fermentor after 30 h of fermentation under constant pH (7) and dissolved oxygen content (40%) were 54% and 2·7 g l,1, respectively. Corresponding yields for control fermentation with sucrose as carbon source were 52% and 2·5 g l,1. The polymer was characterized by proton NMR. Conclusions:, Utilization of mahua flowers, a natural substrate for bacterial fermentation aimed at PHA production, had additional advantage, as the sugars and organic acids present in the flowers were metabolized by Bacillus sp-256 to synthesize P(HB-co-HV) copolymer. Significance and Impact of the Study:, Literature reports on utilization of suitable cheaper natural substrate for PHA copolymer production is scanty. Mahua flowers used in the present experiment is a cheaper carbon substrate compared with several commercial substrates and it is rich in main carbon as well as co-carbon sources that can be utilized by bacteria for PHA copolymer production. [source] Photocatalytic degradation of gaseous trichloroethene using immobilized ZnO/SnO2 coupled oxide in a flow-through photocatalytic reactorJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2005Taicheng An Abstract The photocatalytic degradation of gaseous trichloroethene (TCE) was investigated on immobilized ZnO/SnO2 coupled oxide in a flow-through photocatalytic reactor. It was found that gaseous photocatalysis is an efficient method for volatile organic compounds' abatement and air purification. Degradation of ,100% was found for TCE at the concentrations examined, up to 400 ppmv, in a flow-through dry synthetic gas stream. In our tested conditions, the flow rate had little influence on the photocatalytic degradation efficiencies of TCE, while the relative humidity had a significant influence on the photocatalytic degradation of TCE. The photocatalytic degradation efficiencies of TCE increased slowly below 20% relative humidity and then decreased as the relative humidity increased further. The deactivation of used immobilized photocatalyst was not observed within the 200 h testing period in the present experiment, although the surface of the photocatalyst changed greatly during the use of the photocatalyst. Copyright © 2004 Society of Chemical Industry [source] The effect of a fibrin glue on the integration of Bio-Oss® with bone tissueJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2002An experimental study in labrador dogs Abstract Background: Bio-Oss® is a deproteinized bovine mineral used in bone augmentation procedures. The particles are often mixed with a protein product (Tisseel®) to form a mouldable graft material. Aim: The aim of the present experiment was to study the healing of self-contained bone defects after the placement of Bio-Oss® particles alone or mixed with Tisseel® in cylindrical defects in the edentulous mandibular ridge of dogs. Material and methods: In 4 labrador dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. 3 months later, 3 cylindrical bone defects, 4 mm in diameter and 8 mm in depth, were produced in the right side of the mandible. Following a crestal incision, full thickness flaps were raised and the bone defects were prepared with a trephine drill. The defects were filled with Bio-Oss® (Geistlich Biomaterials, Wolhuser, Switzerland) particles alone or mixed with Tisseel® (Immuno AG, Vienna, Austria), or left "untreated". A collagen membrane (Bio-Gide®, Geistlich Biomaterials, Wolhuser, Switzerland) was placed to cover all defects and the flaps were sutured. 2 months later, the defect preparation and grafting procedures were repeated in the left side of the mandible. After another month, the animals were sacrificed and biopsies obtained from the defect sites. Results: Bio-Oss® -treated defects revealed a higher percentage of contact between graft particles and bone tissue than defects treated with Bio-Oss®+ Tisseel® (15% and 30% at 1 and 3 months versus 0.4% and 8%, respectively). Further, the volume of connective tissue in the Bio-Oss® treated defects decreased from the 1 to the 3 month interval (from 44% to 30%). This soft tissue was replaced with newly formed bone. In the Bio-Oss®+ Tisseel® treated defects, however, the proportion of connective tissue remained unchanged between 1 and 3 months. Conclusion: The adjunct of Tisseel® may jeopardize the integration of Bio-Oss® particles with bone tissue. Zusammenfassung Hintergrund: Bio-Oss® ist ein entproteiniertes Mineral vom Schwein, was bei knöchernen Augmentationen verwendet wird. Die Partikel werden oft mit einem Proteinprodukt gemischt, um ein formbares Implantationsmaterial zu erhalten. Ziel: Das Ziel des vorliegenden Experimentes war das Studium der Heilung von selbst-erhaltenden Knochendefekten nach der Anwendung von Bio-Oss® Partikeln allein oder vermischt mit Tisseel® in zylindrischen Defekten im zahnlosen unteren Kieferkamm von Hunden. Materal und Methoden: Bei 4 Labradorhunden wurden die 2., 3. und 4. unteren Prämolaren beidseitig extrahiert. 3 Monate später wurden 3 zylindrische Knochendefekte, 4 mm im Durchmesser und 8 mm tief, auf der rechten Seite des Unterkiefers hergestellt. Nach einer krestalen Incision wurde ein voller Mukoperiostlappen mobilisiert und die knöchernen Defekte mit einem Trepanfräser präpariert. Die Defekte wurden mit Bio-Oss® Partikeln (Geistlich Biomaterial, Wolhuser, Schweiz) allen oder gemischt mit Tisseel® (Immuno AG, Wien, Österreich) gefüllt oder blieben "unbehandelt". Eine Kollagenmembran (Bio-Gide®, Geistlich Biomaterial, Wolhuser, Schweiz) wurde zur Abdeckung über alle Defekte gelegt und die Lappen reponiert und vernäht. 2 Monate später wurden die Defektpräparationen und die Implantationsmaßnahmen auf der linken Seite des Unterkiefers widerholt. Nach einem weiteren Monat wurden die Tiere getötet und Biopsien von den Defektseiten gewonnen. Ergebnisse: Mit Bio-Oss® behandelte Defekte zeigten einen höheren Prozentsatz von Kontakt zwischen Implantationsmaterial und Knochengewebe als die Defekte, die mit Bio-Oss® und Tisseel® behandelt worden waren (15% und 30% zum 1. Monat und 3. Monat versus 0.4% und 8%). Weiterhin verringerte sich das Volumen des Bindegewebes in den mit Bio-Oss® behandelten Defekten vom 1. zum 3. Monat (von 44% zu 30%). Dieses Weichgewebe wurde mit neu gebildetem Knochen ersetzt. In dem mit Bio-Oss® und Tisseel® behandelten Defekten blieb die Verteilung des Bindegewebes zwischen dem 1. und 3. Monat unverändert. Zusammenfassung: Die Zugabe von Tisseel® kann die Integration von Bio-Oss® Partikeln mit Knochengewebe behindern. Résumé Origine: Le Bio-Oss® est un minéral bovin déprotéine utilisé pour les épaississements osseux. Les particules sont souvent mélangées avec un produit protéiné (Tisseel®) pour former un matérial de greffe malléable. But. Le but de l'étude présente a été d'étudier la guérison des lésions osseuses après le placement de particules de Bio-Oss® seules ou mélangées au Tisseel® dans des lésions cylindriques au niveau de la mandibule édentée de labradors. Matériaux et méthodes: Chez 4 labradors les 2ièmes, 3ièmes et 4ièmes prémolaires inférieures ont été avulsées bilatéralement. 3 mois après, 3 lésions osseuses et cylindriques de 4 mm de diamètre et de 8 mm de profondeur ont été produites du côté droit de la mandibule. A la suite d'une incision crestale, des lambeaux d'épaisseur complète ont été relevés et les lésions osseuses préparées avec un trépan. Les lésions ont été comblées par des particules de Bio-Oss® seul (Geistlich Biomaterials, Wolhuser, Suisse) ou mélangées au Tisseel® (Immuno AG, Vienne) ou laissées non-traitées. Une membrane collagène (Bio-Gide®, Geistlich Biomaterials, Wolhuser, Suisse) a été placée pour recouvrir toutes les lésions et les lambeaux ont ensuite été suturés. 2 mois après, les processus précités ont été répétés au niveau gauche de la mandibule. 1 mois plus tard, les animaux ont été tués et les biopsies prélevées. Résultats: Les lésions traitées par le Bio-Oss® ont révélé un % plus important de contact entre les particules du greffon et le tissu osseux que les lésions traitées avec le Bio-Oss®+Tisseel® (respectivement 15% à 30% à 1 et 3 mois versus 0.4% et 8%). De plus le volume de tissu conjonctif dans les lésions traitées par Bio-Oss® diminuait du mois 1 au mois 3, de 44 à 30%. Ce tissu mou a été remplacé par un os néoformé. Dans les lésions traitées par Bio-Oss®+Tisseel®, la proportion de tissu conjonctif demeurait inchangée entre les mois 1 et 3. Conclusions: L'addition de Tisseel® peut mettre en péril l'intégration des particules de Bio-Oss® au tissu osseux. [source] Processes underlying deception: an empirical analysis of truth and lies when manipulating the stakesJOURNAL OF INVESTIGATIVE PSYCHOLOGY AND OFFENDER PROFILING, Issue 3 2005Letizia Caso Abstract The aim of the present experiment was to examine to what extent participants experience attempted control, cognitive load and arousal when they lie and tell the truth under lower-stakes and higher-stakes conditions. We expected both differences and similarities between truth tellers and liars. We expected that participants would experience these processes to a higher degree when they lied compared to when they told the truth (differences), but we also expected that both liars and truth tellers would be keen to make a convincing impression; and that raising the stakes would affect liars and truth tellers in a similar way (similarities). A total of 128 participants lied and told the truth during an interview (lying and truth telling was counterbalanced). Stakes were manipulated by informing half of the participants that their interviews would be recorded on videotape and would be analysed and evaluated by police officers. The predictions were supported. Copyright © 2005 John Wiley & Sons, Ltd. [source] Preparation and characterization of a customized cellulose acetate butyrate dispersion for controlled drug deliveryJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2002Siva Vaithiyalingam Abstract The purpose of the present experiment was to prepare and characterize the aqueous-based pseudolatex system of cellulose acetate butyrate (CAB) for controlled drug delivery. Aqueous pseudolatex systems are advantageous over organic-based coating systems because these systems are devoid of criteria pollutants such as carbon monoxide, nitrogen oxides, nonmethane volatile organic compounds, and sulfur dioxide. Pseudolatex was prepared with CAB and polyvinyl alcohol (stabilizer) by a polymer emulsification technique. The stability of pseudolatex was evaluated. Particle size was measured and rheological experiments were conducted. The glass transition temperature, microscopic free volume, permeation coefficient, and mechanical properties of plasticized pseudolatex films were estimated. Surface roughness of coating on inert Nu-Pareil® beads (Ingredient Technology Corp., Mahwah, NJ) was measured as a function of coating weight gain. The CAB Pseudolatex was found to be stabilized by steric forces. From intrinsic viscosity, the thickness of the stabilization layer was estimated. An increase in polymeric particles proportionately decreased the thickness of the stabilization layer. All the essential properties of a coating membrane such as microscopic free-volume fraction, permeability coefficient, mechanical properties, and glass transition temperature were fairly controllable as a function of plasticizer concentration. The pseudolatex dispersion of CAB was stable with negligible sedimentation volume and a particle size of 300 nm. Because CAB is water insoluble and non-ionizable, this pseudolatex can be used for pH-independent coating. The films obtained were strong and flexible for controlled drug delivery applications. Coating with the CAB dispersion reduced the surface roughness of beads but it remained stable as a function of increase in coating weight gain. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:1512,1522, 2002 [source] Remission and Resurgence of Anxiety-Like Behavior Across Protracted Withdrawal Stages in Ethanol-Dependent RatsALCOHOLISM, Issue 9 2007Yu Zhao Background:, Alcohol dependence is a chronic disorder in which withdrawal symptoms often persist after detoxification. The purpose of the present experiment was to characterize susceptibility to stress and anxiogenic stimuli in rats over an extended time period following ethanol withdrawal. Methods:, Male Wistar rats were made dependent via ethanol vapor exposure. The rats were then tested in the elevated plus-maze during acute ethanol withdrawal (ACW, ,8 hour), early "protracted" withdrawal (EPW, 2 weeks), or late "protracted" withdrawal (LPW, 6, 12 weeks) following brief restraint or no stress. Principal components analysis was used to identify constructs underlying plus-maze behavior. Results:, Three factors characterized plus-maze performance: anxiety, locomotor activity, and risk assessment/decision making. Spontaneous anxiety-like behavior was increased during ACW, decreased to levels of ethanol-naïve controls during EPW, but markedly resurged during LPW. Withdrawal did not alter sensitivity to the anxiety-like effects of restraint stress. All ethanol-dependent rats showed locomotor hypoactivity that, in contrast to anxiety, remained stable throughout all withdrawal stages. Neither ethanol withdrawal nor restraint stress altered mean "risk assessment/decision making" scores, though ethanol withdrawal altered the emission of "risk assessment/decision making" behavior in relation to anxiety-like behavior and behavioral activation state. Conclusions:, The findings illustrate and model the spontaneous, severe, and long-lasting nature of behavioral abnormalities that accompany withdrawal from chronic, intermittent ethanol intoxication. The dynamic remission and resurgence in symptoms of negative affect (i.e., behavioral signs of anxiety) during "protracted" withdrawal may complicate recovery from alcoholism. [source] Effect of Yttrium and Erbium Ions on Epitaxial Phase Transformations in AluminaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2003Deirdre D. Ragan The effect of low concentrations of Y, Er, and Cr solutes on the amorphous-to-, transformation and on the ,-to-, transformation in aluminum oxide has been studied in situ by time-resolved reflectivity. The activation energies of the two transformations with these dopants are the same as in undoped alumina, being 4.1 ± 0.1 and 5.2 ± eV, respectively. Although not affecting the activation energies, Y, Er, and Cr do affect the transformation kinetics. Y and Cr ions decrease the ,-to-, transformation velocity and, over the limited range studied, do so in proportion to their concentration. Concentrations of Er as low as ,6 ppm retard the ,-to-, transformation and concentrations of 32 ppm essentially stop the transformation occurring within the times and temperatures accessible within the present experiment, thereby preventing quantification of the effect of Er on the ,-phase transformation. Erbium also retards the amorphous-to-, transformation relative to undoped alumina whereas yttrium and chromium accelerate it. [source] Changes of maternal transcripts in oocytes from persistent follicles in cattleMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 3 2007Brandon M. Lingenfelter Abstract A high incidence of early embryonic loss is associated with prolonged dominance of follicles. The objective of the present experiment was to determine if persistence of a follicle resulted in alterations in mRNA expression of important genes in the oocyte. Cows were assigned to four groups: growing follicles on day 6 (G0h) or day 8 (G48h) and persistent follicles on day 13 (P0h) or day 15 (P48h) of the estrous cycle (estrus,=,day 0). All cows were super-stimulated on day 1,4. Cows in G48h, P0h, and P48h groups received 25 mg prostaglandin (PG) F2, on day 6. Cows in P0h and P48h groups received progesterone from CIDR-B devices on day 5 through 13. Ovaries of cows in G0h, G48h, P0h, and P48h groups were removed on day 6, 8, 13, and 15, respectively. Oocytes were aspirated immediately after colpotomy and denuded of cumulus cells. Quantitative real-time PCR was used to measure the mRNA abundances of 10 selected genes important for early embryogenesis in oocytes obtained from growing and persistent follicles. Relative abundances of MSY2, PARN, and YY1 mRNA (P,<,0.05) were significantly lower in oocytes from persistent than from growing follicles. Oocytes from persistent follicles, however, had greater abundances of PAP and eIF-4E transcripts (P,<,0.05). The data indicate that persistence of a follicle leads to altered abundances of mRNA for genes important for regulation of transcription and protein translation in the oocyte, which could compromise development of early embryos in cows that ovulate a persistent follicle. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source] Accommodation microfluctuations and pupil size during sustained viewing of visual display terminalsOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2000L.S. Gray Summary Accommodation microfluctuations comprise two dominant frequencies; a low frequency component (LFC0.6 Hz) and a high frequency component (1.0 Hz Construction of a Primary RH Panel of Italian Ryegrass Genome via UV-Induced Protoplast FusionPLANT BIOLOGY, Issue 5 2006A. Cheng Abstract: Symmetric and asymmetric somatic hybrids were produced via protoplast fusion between common wheat (Triticum aestivum L.) cv. "Jinan 177" and Italian ryegrass (Lolium multiflorum Lam.). The ryegrass without or with UV irradiation was used as a donor, providing a small amount of chromatin. In these somatic hybrids, most ryegrass chromosomes have been confirmed preferential elimination and the somatic hybrid calli and plants showed wheat-like morphology. Some of the hybrid lines were used for the analysis of distribution and heredity of donor DNA in the hybrid genome and the possibility of establishing a radiation hybrid (RH) panel of the ryegrass in the present experiment. These hybrids, subcultured for two and three years, retained the ryegrass DNA examined by RFLP and GISH analysis, respectively. Distribution of the ryegrass DNA in the wheat genomes of 20 single-cell individuals, randomly selected from hybrid cell lines produced, were analyzed by 21 ryegrass genome specific SSR markers. The average frequencies of molecular marker retention in symmetric hybrid lines (UV 0), as well as asymmetric hybrid lines from UV 30 s and 1 min were 10.88, 15.48 and 33.86, respectively. It was suggested that the UV dose increased the introgression of donor DNA into wheat genome. The ryegrass SSR fragments in most asymmetric hybrid cell lines remained stable over a period of 2 , 3 years. This revealed that those asymmetric somatic hybrids are suitable for the introgression of ryegrass DNA into wheat, and for RH panel and RH mapping. [source] Testing the boundaries of the choice overload phenomenon: The effect of number of options and time pressure on decision difficulty and satisfactionPSYCHOLOGY & MARKETING, Issue 3 2009Graeme A. Haynes The number of alternatives available to people in many day-to-day decisions has greatly increased in Western societies. The present research sought to build upon recent research suggesting that having large numbers of alternatives can sometimes have negative consequences for individuals. In the present experiment, participants were presented with descriptions of either 3 or 10 prizes and asked to choose one, for which they were to be entered in a drawing. The number of alternatives was manipulated in conjunction with the amount of time people were allotted to make a decision (limited vs. extended decision time). Following their decisions, participants completed measures of decision-related difficulty, task enjoyment, satisfaction, and regret. Participants given a limited amount of time to choose with a larger set of alternatives found their decisions to be more difficult and frustrating than did participants in the other conditions. The larger set of alternatives led to less satisfaction, but not less regret, with people's decisions. Implications for research on the choice overload phenomenon are discussed. © 2009 Wiley Periodicals, Inc. [source] Contextual cueing effects despite spatially cued target locationsPSYCHOPHYSIOLOGY, Issue 4 2010Andrea Schankin Abstract Reaction times (RT) to targets are faster in repeated displays relative to novel ones when the spatial arrangement of the distracting items predicts the target location (contextual cueing). It is assumed that visual,spatial attention is guided more efficiently to the target resulting in reduced RTs. In the present experiment, contextual cueing even occurred when the target location was previously peripherally cued. Electrophysiologically, repeated displays elicited an enhanced N2pc component in both conditions and resulted in an earlier onset of the stimulus-locked lateralized readiness potential (s-LRP) in the cued condition and in an enhanced P3 in the uncued condition relative to novel displays. These results indicate that attentional guidance is less important than previously assumed but that other cognitive processes, such as attentional selection (N2pc) and response-related processes (s-LRP, P3) are facilitated by context familiarity. [source] Error-related brain potentials are differentially related to awareness of response errors: Evidence from an antisaccade taskPSYCHOPHYSIOLOGY, Issue 5 2001Sander Nieuwenhuis The error negativity (Ne/ERN) and error positivity (Pe) are two components of the event-related brain potential (ERP) that are associated with action monitoring and error detection. To investigate the relation between error processing and conscious self-monitoring of behavior, the present experiment examined whether an Ne and Pe are observed after response errors of which participants are unaware. Ne and Pe measures, behavioral accuracy, and trial-to-trial subjective accuracy judgments were obtained from participants performing an antisaccade task, which elicits many unperceived, incorrect reflex-like saccades. Consistent with previous research, subjectively unperceived saccade errors were almost always immediately corrected, and were associated with faster correction times and smaller saccade sizes than perceived errors. Importantly, irrespective of whether the participant was aware of the error or not, erroneous saccades were followed by a sizable Ne. In contrast, the Pe was much more pronounced for perceived than for unperceived errors. Unperceived errors were characterized by the absence of posterror slowing. These and other results are consistent with the view that the Ne and Pe reflect the activity of two separate error monitoring processes, of which only the later process, reflected by the Pe, is associated with conscious error recognition and remedial action. [source] Changes in estrogen receptor alpha expression in the bursa of Fabricius during chick embryonic developmentANIMAL SCIENCE JOURNAL, Issue 1 2008Young-Ha SHIN ABSTRACT Sex steroid hormones have been reported to be modulators that augment or suppress immune functions. Applying estrogen to chick embryos has been reported to influence antibody production after hatching, suggesting that estrogen acts on B cell differentiation and proliferation in the bursa of chick embryos. We previously reported the presence of estrogen receptor , (ER,) in the bursa during the late period of embryogenesis. In the present study we examined the time course of ER, expression in the bursa of chick embryos at the late period of embryogenesis by ER,-messenger RNA (mRNA) expression analysis by reverse-transcription-polymerase chain reaction (RT-PCR) using primers for chicken ER,, and immunohistochemistry using an anti-ER antibody. The quantity of ER,-mRNA expressed, estimated from the relative densities of the ER, RT-PCR products to those of ,-actin, changed with time during the late period of embryogenesis (day 10 to day 21). ER,-mRNA expression was observed at all ages examined in the present experiment. The expression increased between day 10 and day 15 of embryogenesis and then the value was decreased between day 15 and day 21 of embryogenesis. The numbers of ER-positive cells in the bursa also changed with time during the late period of embryogenesis (day 14 to day 18). ER-positive cells showed the highest level on day 14 of embryogenesis, and then the value declined. ER-positive cells were observed in lymphoid follicular cells, stromal cells and epithelial cells, and the density of ER-positive cells was highest in epithelial cells among the three cell components of the bursa. The high level of ER expression in the bursa of Fabricius (BF) of chick embryos at the late period of embryogenesis suggests that this stage of embryogenesis is critical in B cell differentiation in the bursa in connection with estrogen effects on antibody production after hatching. [source] See no lies, hear no lies: differences in discrimination accuracy and response bias when watching or listening to police suspect interviewsAPPLIED COGNITIVE PSYCHOLOGY, Issue 8 2008Samantha Ann Mann In the present experiment, police officers attempted to detect truths and lies told by suspects in their police interviews in three different ways: They either saw the suspects (visual condition), only heard the suspects (audio condition) or both saw and heard the suspects (control condition). Research has demonstrated that vocal and speech-related cues are better diagnostic cues to deceit than visual cues. Therefore, we predicted that participants in the visual condition would perform worst in the lie detection task. Having access only to visual cues may encourage observers to be more reliant on stereotypical beliefs when attempting to detect truths and lies. Since these stereotypes are related to the behaviour of liars, rather than to the behaviour of truth tellers, we further predicted that being exposed only to visual cues may result in a lie bias. The findings supported these hypotheses, and the implications are discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Marine yeast diet confers better protection than its cell wall component (1-3)-,- d -glucan as an immunostimulant in Fenneropenaeus indicusAQUACULTURE RESEARCH, Issue 15 2009Thavarool Puthiyedathu Sajeevan Abstract A comparative study was performed to evaluate the immunostimulatory effect of yeast and yeast-derived glucan in white prawn Fenneropenaeus indicus (sub-adults of ,20 gm). Feed with a whole cell biomass of marine yeast Candida sake S165 (CSY) at a concentration of 10% (w/w) and another feed with 0.2% glucan of C. sake S165 (CSG) were used in the study. Fenneropenaeus indicus were fed with these diets for 40 days and subsequently challenged with the white spot syndrome virus (WSSV). Haematological parameters such as the total haemocyte count, phenoloxidase activity, superoxide anion (O2,) level, haemolymph peroxidase level and post-challenge survival against WSSV infection were determined to assess the immune status. In the present experiment, a higher immunity index and post-challenge survival were recorded in shrimps fed with the whole cell yeast diet. The better immunostimulatory performance of the whole cell yeast diet compared with the glucan diet could be attributed to the cellular constituents of yeast including the cell wall glucan, nucleotides, carotenoid pigments and vitamins. Here we observed that whole cell yeast performed better as an immunostimulant than the extracted cell wall glucans. Therefore, the use of yeast biomass in diets, rather than the yeast cell wall extract, glucan, would confer better protection against microbial infection besides reducing the cost of shrimp production. [source] Effects of 7,12-dimethylbenz(a)anthracene on growth and haematological parameters in Korean rockfish, Sebastes schlegeli (Hilgendorf)AQUACULTURE RESEARCH, Issue 5 2006Jung-Hoon Jee Abstract The objectives of the present experiment were to determine the effects on growth factors and some haematological parameters in Korean rockfish, Sebastes schlegeil, after dietary 7,12-dimethylbenz(a)anthracene (DMBA) exposure at 0.6, 1.2, 2.4 and 4.8 mg kg,1 diet for 8 weeks. The specific growth rate of the fish exposed to DMBA (,1.2 mg kg,1) showed significantly lower performance than the control. Following 8 weeks of exposure, the DMBA-exposed groups (2.4 and 4.8 mg kg,1) had a significantly higher mean hepatosomatic index. Condition factor of the fish exposed to DMBA did not show any statistically significant deviation from the control (P>0.05), although the mean values were somewhat lower than those of the control group. Observations on haematological parameters indicated DMBA treatment induced a severe anaemia. Total protein, albumin and total cholesterol concentrations decreased following exposure to DMBA at 2.4 and 4.8 mg kg,1. In contrast, serum bilirubin and blood urea nitrogen in fish exposed to DMBA increased. Significant decreases in serum electrolytes, chloride, phosphorus, magnesium and calcium, and osmolality were observed in all DMBA-treatment groups. All DMBA-treatment groups showed a significantly higher activity of lactate dehydrogenase and alkaline phosphatase. Serum transaminase activity after the highest level of 4.8 mg kg,1 DMBA was significantly increased. The key finding from this study is that rockfish exposed to dietary DMBA at concentrations of 1.2 and 2.4 mg kg,1 diet are likely to experience adverse impacts in growth and haematological property respectively. [source] Changes in human EEG alpha activity following exposure to two different pulsed magnetic field sequencesBIOELECTROMAGNETICS, Issue 1 2009C.M. Cook Abstract The present study investigates the effects of a weak (±200 µTpk), pulsed, extremely low frequency magnetic field (ELF MF) upon the human electroencephalogram (EEG). We have previously determined that exposure to pulsed ELF MFs can affect the EEG, notably the alpha frequency (8,13 Hz) over the occipital,parietal region of the scalp. In the present study, subjects (n,=,32) were exposed to two different pulsed MF sequences (1 and 2, used previously) that differed in presentation rate, in order to examine the effects upon the alpha frequency of the human EEG. Results suggest that compared to sham exposure, alpha activity was lowered over the occipital,parietal regions of the brain during exposure to Sequence 1, while alpha activity over the same regions was higher after Sequence 2 exposure. These effects occurred after approximately 5 min of pulsed MF exposure. The results also suggest that a previous exposure to the pulsed MF sequence determined subjects' responses in the present experiment. This study supports our previous observation of EEG changes after 5 min pulsed ELF MF exposure. The results of this study are also consistent with existing EEG experiments of ELF MF and mobile phone effects upon the brain. Bioelectromagnetics 30:9,20, 2009. © 2008 Wiley-Liss, Inc. [source] Ridge alterations following tooth extraction with and without flap elevation: an experimental study in the dogCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2009Mauricio G. Araújo Abstract Background: Different approaches were advocated to preserve or improve the dimension and contour of the ridge following tooth extraction. In some of studies, socket ,flapless extraction' apparently had a successful outcome. Aim: The objective of the present experiment was to compare hard tissue healing following tooth extraction with or without the prior elevation of mucosal full-thickness flaps. Material and methods: Five mongrel dogs were used. The two second mandibular premolars (2P2) were hemi-sected. The mesial roots were retained. By random selection the distal root in one side was removed after the elevation of full-thickness flaps while on the contralateral side, root extraction was performed in a flapless procedure. The soft tissue wound was closed with interrupted sutures. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections , two from the mesial root and two from the healed socket , were prepared, stained and examined in the microscope. Results: The data showed that the removal of a single tooth (root) during healing caused a marked change in the edentulous ridge. In the apical and middle portions of the socket site minor dimensional alterations occurred while in the coronal portion of the ridge the reduction of the hard tissue volume was substantial. Similar amounts of hard tissue loss occurred during healing irrespective of the procedure used to remove the tooth was, i.e. flapless or following flap elevation. Conclusion: Tooth loss (extraction) resulted in marked alterations of the ridge. The size of the alveolar process was reduced. The procedure used for tooth extraction , flapless or following flap elevation , apparently did not influence the more long-term outcome of healing. [source] Subcrestal placement of two-part implantsCLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2009Maria Welander Abstract Objective: The aim of the present experiment was to study the healing around two-part implants that were placed in a subcrestal position. Material and methods: Five mongrel dogs, about 2 years old, were included. The mandibular premolars and the first, second and third maxillary premolars were extracted. Three months later two test and two control implants (OsseoSpeedÔ, 3.5 mm × 8 mm) were placed in one side of the mandible. The implants were placed in such a way that the implant margin was located 2 mm apical to the bone crest. In the test implants, the surface modification extended to the implant margin and, thus, included the shoulder part of the implant. Regular abutments with a turned surface (ZebraÔ) were connected to the control implants, while experimental abutments with a modified surface (TiOblastÔ) were connected to the test implants. A plaque control program that included cleaning of implants and teeth every second day was initiated. Four months later the dogs were euthanized and biopsies were obtained and prepared for histological analysis. Results: The marginal bone level at the test implants was identified in a more coronal position than that at the control implants. In 40% of the test implants, the bone-to-implant contact extended coronal of the abutment/fixture (A/F) border, i.e. in contact with the abutment part of the implant. The connective tissue portion of the peri-implant mucosa that was facing the test abutments contained a higher density of collagen and a smaller proportion of fibroblasts than that at the control sites. Conclusion: It is suggested that osseointegration may occur coronal to the A/F interface of two-part implants. Such a result, however, appears to depend on the surface characteristics of the implant components. [source] Collective Grain Interactions II.CONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2005Non-linear Collective Drag Force Abstract It is found that the collective effects operating at large distances from the grain surface can produce substantial scattering of the ion flux and create an additional collective drag force dominant for large grain densities. The consideration is restricted to large grain charges , = Zde2a /Ti,Di , 1 and Ti /Te , 1 (,eZd being the grain charge in units of electron charge, a being the grain size, ,Di being the ion Debye radius and Te,i being electron and ion temperatures, respectively). For present dusty plasma experiments , , 10,50, the large charges of grains are screened non-linearly and the ion scattering creates non-linear drag force. The present investigation considers effects of scattering by collective grain fields at large distances from the grains. It is found that the physical reason of the importance of collective drag force, calculated in this paper, is related to presence of weakly screened collective field of grains outside the non-linear screening distance depending on grain densities. The amplitude of this collective fields of the grains is determined by non-linear screening at non-linear screening radius. It is shown that for dust densities of present experiments the collective drag force related to this scattering can be of the order of the non-linear drag force caused by scattering inside the non-linear screening radius or even larger. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Protein kinases A and C stimulate the Na+ active transport in frog skeletal muscle without an appreciable change in the number of sarcolemmal Na+ pumpsACTA PHYSIOLOGICA, Issue 4 2005R. A. Venosa Abstract Aim:, The activation of both protein kinases A (PKA) and protein kinases C (PKC) in some cell types increases and in others reduces active Na+ efflux. These effects have been ascribed to either a change in the rate of ionic translocation by a fixed number of Na+ pumps or, a change in the number of plasma membrane pumps. The purpose of the present experiments was to study the effect of activating PKA and PKC on the Na+ extrusion by the Na+ pump in frog skeletal muscle. Methods:, Na+ (22Na+) fluxes and ouabain (3H-ouabain) binding were measured in frog sartorius muscles. Results:, Both activation of PKA and PKC increased the active Na+ extrusion by a factor of two; these effects were not additive. Ouabain binding experiments indicated that the pump stimulation by activation of these kinases is not associated with any significant increase in the number of plasma membrane pumps. Stimulation of the active Na+ efflux by protein kinase activation (no change in the number of sarcolemmal pumps) and by hypotonicity (increase in the number of pumps) could be elicited in the same preparation and they were additive. Conclusion:, It is concluded that in frog skeletal muscle fibres, (1) activation of both PKA and PKC stimulate the Na+ pump by increasing its rate of ionic translocation; and (2) two modes of Na+ active transport (with and without an increase in the number of pumps) are operative, and can be at work simultaneously, a phenomenon to be reckoned with. [source] Search for cerebral G cluster neurons responding to taste stimulation with seaweed in Aplysia kurodai by the use of calcium imagingDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2003Ryusuke Yoshida Abstract The calcium imaging method can detect the spike activities of many neurons simultaneously. In the present experiments, this method was used to search for unique neurons contributing to feeding behavior in the cerebral ganglia of Aplysia kurodai. We mainly explored the neurons whose cell bodies were located in the G cluster and the neuropile region posterior to this cluster on the ventral surface of the cerebral ganglia. When the extract of the food seaweed Ulva was applied to the tentacle-lip region, many neurons stained with a calcium-sensitive dye, Calcium Green-1, showed changes in fluorescence. Some neurons showed rhythmic responses and others showed transient responses, suggesting that these neurons may be partly involved in the feeding circuits. We also identified three motor neurons among these neurons that showed rhythmic fluorescence responses to the taste stimulation. One of them was a motor neuron shortening the anterior tentacle (ATS), and the other two were motor neurons producing lip opening-like (LOG) and closing-like (LCG) movements, respectively. Application of the Ulva extract to the tentacle-lip region induced phase-locked rhythmic firing activity in these motor neurons, suggesting that these neurons may contribute to the rhythmic patterned movements of the anterior tentacles and lips during the ingestion of seaweed. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 299,314, 2003 [source] Dopamine receptors modulate ethanol's locomotor-activating effects in preweanling ratsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2010Carlos Arias Abstract Near the end of the second postnatal week motor activity is increased soon after ethanol administration (2.5,g/kg) while sedation-like effects prevail when blood ethanol levels reach peak values. This time course coincides with biphasic reinforcement (appetitive and aversive) effects of ethanol determined at the same age. The present experiments tested the hypothesis that ethanol-induced activity during early development in the rat depends on the dopamine system, which is functional in modulating motor activity early in ontogeny. Experiments 1a and 1b tested ethanol-induced activity (0 or 2.5,g/kg) after a D1-like (SCH23390; 0, .015, .030, or .060,mg/kg) or a D2-like (sulpiride; 0, 5, 10, or 20,mg/kg) receptor antagonist, respectively. Ethanol-induced stimulation was suppressed by SCH23390 or sulpiride. The dopaminergic antagonists had no effect on blood ethanol concentration (Experiments 2a and 2b). In Experiment 3, 2.5,g/kg ethanol increased dopamine concentration in striatal tissue as well as locomotor activity in infant Wistar rats. Adding to our previous results showing a reduction in ethanol induced activity by a GABA B agonist or a nonspecific opioid antagonist, the present experiments implicate both D1-like and D2-like dopamine receptors in ethanol-induced locomotor stimulation during early development. According to these results, the same mechanisms that modulate ethanol-mediated locomotor stimulation in adult rodents seem to regulate this particular ethanol effect in the infant rat. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52: 13,23, 2010 [source] Predictors of pharmacoresistant epilepsy: Pharmacoresistant rats differ from pharmacoresponsive rats in behavioral and cognitive abnormalities associated with experimentally induced epilepsyEPILEPSIA, Issue 10 2008Alexandra M. Gastens Summary Purpose:, Patients with intractable temporal lobe epilepsy (TLE) exhibit an increased risk of psychiatric comorbidity, including depression, anxiety, psychosis, and learning disorders. Furthermore, a history of psychiatric comorbidity has been suggested as a predictor of lack of response to therapy with antiepileptic drugs (AEDs) in patients with epilepsy. However, clinical studies on predictors of pharmacoresistant epilepsy are affected by several confounding variables, which may complicate conclusions. In the present study, we evaluated whether behavioral alterations in epileptic rats are different in AED nonresponders versus responders. Methods:, For this purpose, we used an animal model of TLE in which AED responders and nonresponders can be selected by prolonged treatment of epileptic rats with phenobarbital (PB). Behavioral and cognitive abnormalities were compared between responders and nonresponders as well as between epileptic rats and nonepileptic controls in a battery of tests. Results:, Fifteen epileptic rats with spontaneous recurrent seizures (SRS) either responding (11 rats) or not responding (4 rats) to PB were used for this study. The nonresponders differed markedly in behavioral and cognitive abnormalities from responders and nonepileptic controls in tests of anxiety (open field, elevated-plus maze test), behavioral hyperexcitability (approach-response, touch-response, pick-up tests), and learning and memory (Morris water maze). Discussion:, Our hypothesis that AED-resistant rats will show more severe behavioral and cognitive changes than AED-responsive rats was confirmed by the present experiments. The data substantiate that rodent models of TLE are useful to delineate predictors of pharmacoresistant epilepsy. [source]
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