670 research outputs found
The roles of feature prototypicality and encoding strategies on the salience of features in facial recognition
No full textSeveral lines of investigation suggest the utilization of a schema in memory for human faces. For example, when faces have undergone some transformation (inversion or reordering of feature position) they are disproportionately difficult to recognize compared to other objects. This result suggests that recognition processes utilizing a schema, or template, are disrupted when facial stimuli are changed from their normal state. Frame theory provides a delineation of processes which might be utilized when schemata, or prototypes, are used in human memory. The memorial frame may be conceptualized as a hierarchy of nodes and relations. The top levels are fixed and represent aspects of memorial data structures which are always true, e.g., the spatial relation of facial features. The lower level nodes have many terminals which must be filled with specific information through interaction with the environment during a perceptual event. Terminals, until reassigned during a perceptual event, are filled with prototypical, default values. Information about an individual perceptual event is stored in episodic memory as the occurrence of a particular frame instantiation and the deviations of that event from the prototypical default values. The roles of features exemplar prototypicality and encoding strategy in the recognition of faces and facial feature salience were investigated. Subjects performed a facial recognition task and a feature discrimination task. In the recognition task a target face was presented for four seconds. Following a delay of four seconds, either the target face or a face in which a single facial feature was changed was presented. Subjects time to judge the second face as same or different was measured. In the feature discimination task the subject judged a single facial feature same or different. Five groups of subjects utilized different encoding strategies: verbal/wholistic, verbal/featural, imaginal/wholistic, imaginal/feature, and an uninstructed control group. Experimental manipulations center on the single feature changed from target to distractor. Features exemplars used in the recognition tasks were selected from a larger set of features rated with respect to typicality by a similar group of subjects. Features rated as unusual (atypical) and average (typical) were used. Each of the five facial features (hair (H), eyes (E), nose (N), mouth (M), and chin (C)) was changed. Target faces were constructed with one atypical feature and four typical features. Four types of feature change with respect to typicality levels occurred: atypical to different atypical (A-A), atypical to typical (A-T), typical to atypical (T-A), and typical to different typical (T-T). Results indicated differential feature discriminability RT's for the five facial features; H<E[equals]N[equals]M[equals]C. Also, discriminability differed for the four change types, T-A<A-A<A-T<T-T. Accounts of discrimination based only on inter-item similarity of feature exemplar do not predict this finding. A model of discrimination is proposed in which prototypicality information in the comparison face guides processing. Effects of typicality on the salience of facial features in the recognition process were assessed by first substracting discrimination time from whole face recognition time. Differential feature salience was evident in the derived RT measure, E<H<M[equals]C<N. However, for the A-A change the observed feature salience was H=E=M=C<N. Prototypicality of the changed feature affects salience. Typicality of the changed feature also affects the recognition process. An account of recognition is discussed in which lists of feature deviations from prototypicality derived from both target and comparison face influence the recognition process. The account provides an explanation for the observered ordering of change types, A-A<T-A[equals]A-T[equals]T-T. Encoding strategies used did not affect the nature of recognition or discrimination processes. However, the use of verbal strategies increased the time necessary for processing compared to imagery strategies and the control group.Psychology, Department o
Proteomic Profile of Circulating Extracellular Vesicles in the Brain after Δ9-Tetrahydrocannabinol Inhalation
No full textGiven the increasing use of cannabis in the US, there is an urgent need to better understand the drug's effects on central signaling mechanisms. Extracellular vesicles (EVs) have been identified as intercellular signaling mediators that contain a variety of cargo, including proteins. Here, we examined whether the main psychoactive component in cannabis, Δ9-tetrahydrocannabinol (THC), alters EV protein signaling dynamics in the brain. We first conducted in vitro studies, which found that THC activates signaling in choroid plexus epithelial cells, resulting in transcriptional upregulation of the cannabinoid 1 receptor and immediate early gene c-fos, in addition to the release of EVs containing RNA cargo. Next, male and female rats were examined for the effects of either acute or chronic exposure to aerosolized ('vaped') THC on circulating brain EVs. Cerebrospinal fluid was extracted from the brain, and EVs were isolated and processed with label-free quantitative proteomic analyses via high-resolution tandem mass spectrometry. Interestingly, circulating EV-localized proteins were differentially expressed based on acute or chronic THC exposure in a sex-specific manner. Taken together, these findings reveal that THC acts in the brain to modulate circulating EV signaling, thereby providing a novel understanding of how exogenous factors can regulate intercellular communication in the brain
The computer science graduate record exam tutorial courseware, 1994
No full textThe design and development of Computer Science Graduate Record Examination Tutorial Software will be discussed. The courseware reviews Computer Design, File Structures, Data Structures, and Discrete Math to thoroughly prepare students for the exam. A demonstration of the software is included on diskette
hERG Blockade by Iboga Alkaloids
No full textAbstract
The iboga alkaloids are a class of naturally occurring and synthetic compounds, some of which modify drug self-administration and withdrawal in humans and preclinical models. Ibogaine, the prototypic iboga alkaloid that is utilized clinically to treat addictions, has been associated with QT prolongation, torsades de pointes and fatalities. hERG blockade as IKr was measured using the whole-cell patch clamp technique in HEK 293 cells. This yielded the following IC50 values: ibogaine manufactured by semisynthesis via voacangine (4.09 ± 0.69 μM) or by extraction from T. iboga (3.53 ± 0.16 μM); ibogaine's principal metabolite noribogaine (2.86 ± 0.68 μM); and voacangine (2.25 ± 0.34 μM). In contrast, the IC50 of 18-methoxycoronaridine, a product of rational synthesis and current focus of drug development was >50 μM. hERG blockade was voltage dependent for all of the compounds, consistent with low-affinity blockade. hERG channel binding affinities (K i) for the entire set of compounds, including 18-MC, ranged from 0.71 to 3.89 μM, suggesting that 18-MC binds to the hERG channel with affinity similar to the other compounds, but the interaction produces substantially less hERG blockade. In view of the extended half-life of noribogaine, these results may relate to observations of persistent QT prolongation and cardiac arrhythmia at delayed intervals of days following ibogaine ingestion. The apparent structure-activity relationships regarding positions of substitutions on the ibogamine skeleton suggest that the iboga alkaloids might provide an informative paradigm for investigation of the structural biology of the hERG channel
Scientometric analysis of synchronous references in the Physics Nobel lectures, 1981-1985 : a pilot study
No full textScientometric analysis of synchronous references in the nine Physics Nobel lectures by Nicolaas Bloembergen (1981), Arthur L. Schawlow (1981), Kai M. Siegbahn (1981), Kenneth G. Wilson (1982), Subrahmanyan Chandrasekhar (1983), William A. Fowler (1983), Carlo Rubbia (1984), Simon van der Meer (1984), and Klaus von Klitzing (1985) indicated high variations: No. of Synchronous References ranged from 24 (Meer) to 283 (Siegbahn); Synchronous Self-References ranged from 5 (Rubbia) to 88 (Siegbahn); synchronous references to others ranged from 10 (Chandrasekhar) to 255 (Wilson); Synchronous Self-Reference Rates ranged from 6.66 % (Rubbia) to 65.51 % (Chandrasekhar); Single-Authored References ranged from 15 (Klitzing) to 160 (Wilson); Multi-Authored References ranged from 4 (Chandrasekhar) to 194 (Siegbahn); Collaboration Coefficient in the synchronous references ranged from 0.14 (Chandrasekhar) to 0.75 (Klitzing); and Recency (age of 50 % of the latest references) ranged from 2 (Klitzing) to 18 (Chandrasekhar) years. Seventy five per cent of the references belonged to journal articles. Highly referred journals were Astrophysical Journal, Physical Review B, Physical Review Letters, Arkiv Fuer Fysik, Surface Science, Physics Letters, and IEEE Transactions on Nuclear Science.
See: Scientometrics Vol. 61 No.1, pp.55-68
A comparison of two versions of the Cognitive Therapy Scale
No full textThe Cognitive Therapy Scale is a well-established tool for assessing skills in delivering cognitive therapy, but has been subject to criticism. It has recently been updated by two groups, producing the Revised version or CTS-R (Blackburn, James, Milne and Reichelt, 2000) and a version designed for therapy of psychosis, the CTS-Psy (Haddock et al., 2001). The present study made a direct comparison of these scales to evaluate their inter-rater reliability, the extent to which they measure the same therapist qualities, and their utility for assessment of
skills in trainee therapists working with different client-types. Twenty-six trainees submitted tapes of therapy with clients suffering either personality disorder or psychosis. Each tape was
rated by two independent assessors on each of the two scales. Results suggest the scales are both fairly easy to use and produce highly similar estimates of student competence. Client
diagnosis has no significant influence on the scores obtained by the therapist. However, interrater reliability is relatively low. It is concluded that safeguards are needed where these scales
are used as a training outcome measure
The mother of all wars : a critical interpretation of Bertolt Brecht's Mutter Courage und ihre Kinder
No full textThis dissertation interprets Brecht's Mutter Courage through its protagonist. Most interpreters have derived Courage's meaning from only one term of the contradiction of merchant and mother that constitutes her, either blaming the inhuman, war-mongering merchant for her participation in war, or defending the vital, productive, and nurturing mother for that same (unavoidable) participation. Some have stressed instead the unity formed by Courage's contradiction, without being able to elucidate its meaning. The present interpretation, proceeding from a clue given in scene 7 to the meaning of the text, draws parallels between the drama and Brecht's view of the world, and shows that the world of Mutter Courage is the symbolic representation of capitalism as Brecht knew it during the rise of fascism and the approach of the Second World War. Courage is then shown to be a concentrated form of this symbolic representation; indeed, she turns out to be a representation of capitalism in its "totality". This representation is inseparable from the invocation, through Courage, of the Great Mother archetype. The Great Mother describes a contradictory capitalism that is both a Good Mother in its promising productivity, and a Terrible Mother in its destructive warring and oppression; but she, as the symbol of Nature, also describes a capitalism that had begun to seem even to Brecht like a second Nature. Courage also represents the totality of capitalism (as the Marxist Brecht saw it) by embodying both its "affirmative" aspect (as a merchant who engenders soldiering sons), and (undermining the archetype of the Great Mother) its "critical" aspect as the representation of the resistance of the oppressed to their warring world (as the outlaw who engenders a daughter who rebels against war). The meaning of the drama, then, is the story of Courage as the incarnation of the dialectic of capitalism, a dark tale whose conditions seem eternal, but which contains the promise of something be
La fusion par confinement au moyen de miroirs magnétiques
No full textL'auteur expose les principes du miroir tandem, qui, depuis le milieu des années 1970, a révolutionné les perspectives de la fusion magnétique par miroirs. Après avoir rapporté les premiers résultats obtenus par ces types d'installations, il décrit la réalisation actuellement en cours à Livermore (Etats-Unis) d'un centre d'essais de fusion qui sera fondé sur un dispositif à miroirs tandem (MFTF-B). Il évoque enfin le concept « prometteur » du miroir magnétique à champ inversé, autre variante des configurations à miroirs
A view from the roof: Magmatic stoping in the shallow crust, Chita pluton, Argentina
No full textNearly 2 km of vertical relief and exposure of continuous pluton roof-wall corners around the Chita pluton, northwest Argentina, provides constraints on the 3-D host rock displacement field attending magma emplacement in the shallow crust. The pluton is rectangular in cross-sectional view and consists of weakly to non-deformed granite to granodiorite. Structures in surrounding metasedimentary host rocks are truncated at a knife-sharp contact and are only weakly deflected from their regional orientations. Final emplacement occurred by stoping together with minor doming of the earth's surface. Structural restoration of a cross-section indicates that host-rocks above the pluton may have been domed upwards during emplacement by as much as a few hundred meters, accounting for up to 20% of the exposed pluton volume. The remaining 80% of the space for pluton emplacement was made by downward removal of host-rock from the present level of exposure. Although mechanisms such as floor-subsidence are permissive, late stoping has destroyed evidence for the early emplacement history. However, geometrical constraints provided by exposure of continuous wall-to-roof contacts indicate that early emplacement mechanisms at this level in the crust and immediately below were also dominated by the downward displacement of host rocks through a conduit that now is represented by the solidified pluton. © 2002 Elsevier Science Ltd.Fil: Yoshinobu, Aaron S.. Texas Tech University; Estados UnidosFil: Fowler, T. Kenneth. Exxon Production Research Company; Estados UnidosFil: Paterson, Scott R.. University of Southern California; Estados UnidosFil: Llambias, Eduardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Tickyj, Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Sato, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentin
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