859 research outputs found

    Lexical characteristics of emotional narratives in schizophrenia : Relationships with symptoms, functioning, and social cognition

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    Previous research has suggested that complexity of speech, speech rate, use of emotion words, and use of pronouns are all potential indicators of important clinical components of schizophrenia, but little research has examined the relationships of these disturbances to cognitive variables impaired in schizophrenia, including social cognition. The current study examined these lexical differences to better characterize the cognitive substrates of speech disturbances in schizophrenia. Brief narratives of individuals with schizophrenia (n = 42) and non-clinical controls (n = 48) were compared according to their lexical characteristics, and these were examined for relationships to social cognition and real-world functioning. Significant differences between the groups were found in words per sentence (related to functioning, but not negative symptoms) as well as pronoun use (related to attributional style and theory of mind). Additionally, lexical characteristics effectively distinguished individuals with schizophrenia from non-clinical controls. Language disturbances in schizophrenia seem related to social cognition impairments and real-world functioning, and are a robust indicator of clinical status

    Nondestructive Methods for the Determination of Mechanical Properties of Materials

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    The nondestructive determination of mechanical properties of materials is desirable because of the rising cost of both materials and labor as well as safety concerns. In most alloys, changes in thermal and/or mechanical history results in microstructural changes and consequently different mechanical properties. Thermal or mechanical cycles may result from processing or occur in service. Therefore nondestructive detection of microstructure and mechanical properties would prove useful in all phases of metallurgical use. This paper reports on efforts to determine selected mechanical properties of structural materials by nondestructive means such as electrical, acoustic and magnetic techniques as well as hardness. Various thermal and mechanical conditions have been imposed on aluminum, titanium and ferrous alloys to arrive at a wide range of mechanical properties. It is concluded that the intimate knowledge of the microstructure and environmental effects are essential to select the nondestructive method that is most sensitive to property changes

    Social cognition in schizophrenia: factor structure, clinical and functional correlates

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    Social cognition is consistently impaired in people with schizophrenia, separable from general neurocognition, predictive of real-world functioning, and amenable to psychosocial treatment. Few studies have empirically examined its underlying factor structure

    Ultrasonic Investigation of Tensile Fatigue Overloads in Fatigue Cracks

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    The growth of a fatigue crack is generally modeled in terms of empirical rules such as the Paris law [1] which states that da/dN = A(ΔK)m where a is the crack length, N is the number of fatigue cycles at a particular stress intensity range ΔK and A and m are material constants. Recently, evidence has accumulated that establishes that the full excursion of the applied load or the full stress intensity range does not drive the crack tip forward due to a variety of phenomena often referred to as crack tip shielding [2,3]. This shielding arises as a consequence of the formation of contacting asperities between the surfaces of the fatigue crack. Since these contacting asperities bear a portion of the load, they modify the stress intensity at the tip, thereby altering the growth rate

    Lexical Characteristics of Emotional Narratives in Schizophrenia: Relationships With Symptoms, Functioning, and Social Cognition

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    Prior research has suggested that complexity of speech, speech rate, use of emotion words, and use of pronouns are all potential indicators of important clinical components of schizophrenia, but little research has examined the relationships of these disturbances to cognitive variables impaired in schizophrenia, including social cognition. The current study examined these lexical differences to better characterize the cognitive substrates of speech disturbances in schizophrenia. Brief narratives of individuals with schizophrenia (n = 42) and non-clinical controls (n = 48) were compared according to their lexical characteristics, and these were examined for relationships to social cognition and real-world functioning. Significant differences between the groups were found in words per sentence (related to functioning, but not negative symptoms) as well as pronoun use (related to attributional style and theory of mind). Additionally, lexical characteristics effectively distinguished between individuals with schizophrenia from non-clinical controls. Language disturbances in schizophrenia appear related to social cognition impairments, real-world functioning, and are a robust indicator of clinical status

    Low voltage to high voltage level shifter and related methods

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    A shifter circuit comprises a high and low voltage buffer stages and an output buffer stage. The high voltage buffer stage comprises multiple transistors arranged in a transistor stack having a plurality of intermediate nodes connecting individual transistors along the stack. The transistor stack is connected between a voltage level being shifted to and an input voltage. An inverter of this stage comprises multiple inputs and an output. Inverter inputs are connected to a respective intermediate node of the transistor stack. The low voltage buffer stage has an input connected to the input voltage and an output, and is operably connected to the high voltage buffer stage. The low voltage buffer stage is connected between a voltage level being shifted away from and a lower voltage. The output buffer stage is driven by the outputs of the high voltage buffer stage inverter and the low voltage buffer stage

    Revisiting the validity of measures of social cognitive bias in schizophrenia : Additional results from the Social Cognition Psychometric Evaluation (SCOPE) study

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    Objective The ongoing Social Cognition Psychometric Evaluation (SCOPE) study is in the process of forming a gold-standard battery of social cognition tests for use in clinical trials. Previous SCOPE phases have not acknowledged key differences between social cognition skills and biases, and psychometric validity analyses might provide important information if tailored to bias-related outcomes. This study aims to validate these measures with such bias-related outcomes. Methods Two measures of social cognitive bias – the Ambiguous Intention Hostility Questionnaire (AIHQ; hostile attribution bias) and Trustworthiness Task (distrust bias) – were reviewed according to their relationships to (1) current and prospective symptom levels, (2) questionnaires of trait paranoia and hostility and informant-rated hostility, (3) interpersonal conflict, as well as (4) relationships to measures of trait paranoia, hostility, and interpersonal conflict above and beyond the influence of clinically rated symptoms. Results Results supported hypotheses that social cognitive bias provides information about cognition, symptoms, and functioning related to interpersonal conflict. Each bias demonstrated relationships to trait paranoia questionnaires, hostility, or interpersonal conflict outcomes, and these persisted above and beyond the influence of clinically rated symptoms. Hostile attribution bias also predicted change in symptom levels over a brief interval. Conclusions Overall, the current bias-specific psychometric analysis provides support for continued study of social cognitive biases. Practitioner points • Hostile attribution bias may play a role in important outcome variables given relationships to emotional discomfort and suspiciousness symptoms, trait paranoia and hostility, interpersonal conflict, as well as prospective hostility symptoms. • Distrust bias may also impact real-world functioning, as it is related to hostility, suspiciousness, and positive symptoms, trait paranoia, and hostility. • Relationships of social cognitive biases to interpersonal conflict outcomes exist independently of interview-rated symptoms and persist above and beyond the influence of social cognitive skills, which appear to demonstrate weaker relationships to these outcomes. • Understanding and assessing the individual's biases towards distrust or blame might help practioners predict interpersonal conflict and future increases in symptoms

    Immobilization of Polymer-Decorated Liquid Crystal Droplets on Chemically Tailored Surfaces

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    We demonstrate that the assembly of an amphiphilic polyamine on the interfaces of micrometer-sized droplets of a thermotropic liquid crystal (LC) dispersed in aqueous solutions can be used to facilitate the immobilization of LC droplets on chemically functionalized surfaces. Polymer 1 was designed to contain both hydrophobic (alkylfunctionalized) and hydrophilic (primary and tertiary amine-functionalized) side chain functionality. The assembly of this polymer at the interfaces of aqueous dispersions of LC droplets was achieved by the spontaneous adsorption of polymer from aqueous solution. Polymer adsorption triggered transitions in the orientational ordering of the LCs, as observed by polarized light and bright-field microscopy. We demonstrate that the presence of polymer 1 on the interfaces of these droplets can be exploited to immobilize LC droplets on planar solid surfaces through covalent bond formation (e.g., for surfaces coated with polymer multilayers containing reactive azlactone functionality) or through electrostatic interactions (e.g., for surfaces coated with multilayers containing hydrolyzed azlactone functionality). The characterization of immobilized LC droplets by polarized, fluorescence, and laser scanning confocal microscopy revealed the general spherical shape of the polymer-coated LC droplets to be maintained after immobilization, and that immobilization led to additional ordering transitions within the droplets that were dependent on the nature of the surfaces with which they were in contact. Polymer 1-functionalized LC droplets were not immobilized on polymer multilayers treated with poly(ethylene imine) (PEI). We demonstrate that the ability to design surfaces that promote or prevent the immobilization of polymer-functionalized LC droplets can be exploited to pattern the immobilization of LC droplets on surfaces. The results of this investigation provide the basis of an approach that could be used to tailor the properties of dispersed LC emulsions and to immobilize these droplets on functional surfaces of interest in a broad range of fundamental and applied contexts

    Dynamic Ordering Transitions of Liquid Crystals Driven by Interfacial Complexes Formed Between Polyanions and Amphiphilic Polyamines

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    We report the design of an amphiphilic polyamine (polymer 1) based on poly(2-alkenyl azlactone) that strongly couples the formation of polyelectrolyte complexes at aqueous/liquid crystal (LC) interfaces to ordering transitions in the LC. We demonstrate that the addition of a strong anionic polyelectrolyte to aqueous solutions in contact with polymer 1-laden LC interfaces (prepared by Langmuir-Schaefer transfer of monolayers of polymer 1 onto micrometerthick films of nematic LC) triggers ordering transitions in the LCs. We further demonstrate that changes in the ordering of the LCs (i) are driven by electrostatic interactions between the polyelectrolytes, (ii) involve multivalent interactions between the polyelectrolytes, and (iii) are triggered by reorganization of the hydrophobic side chains of amphiphilic polymer 1 upon formation of the interfacial complexes. The results presented in this paper lead us to conclude that ordering transitions in LCs can be used to provide insights into the structure and dynamics of interfacial complexes formed between polyelectrolytes

    Langmuir Films of Flexible Polymers Transferred to Aqueous/Liquid Crystal Interfaces Induce Uniform Azimuthal Alignment of the Liquid Crystal

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    We reported recently that amphiphilic polymers can be assembled at interfaces created between aqueous phases and thermotropic liquid crystals (LCs) in ways that: (i) couple the organization of the polymer to the order of the LC and (ii) respond to changes in the properties of aqueous phases that can be characterized as changes in the optical appearance of the LC. This investigation sought to characterize the behavior of aqueous-LC interfaces decorated with uniaxially compressed thin films of polymers transferred by Langmuir-Schaefer (LS) transfer. Here, we report physicochemical characterization of interfaces created between aqueous phases and the thermotropic LC 4-cyano-4′-pentylbiphenyl (5CB) decorated with Langmuir films of a novel amphiphilic polymer (polymer 1), synthesized by the addition of hydrophobic and hydrophilic side chains to poly(2-vinyl-4,4′-dimethylazlactone). Initial characterization of this system resulted in the unexpected observation of uniform azimuthal alignment of 5CB after LS transfer of the polymer films to aqueous-5CB interfaces. This paper describes characterization of Langmuir films of polymer 1 hosted at aqueous-5CB interfaces as well as the results of our investigations into the origins of the uniform ordering of the LC observed upon LS transfer. Our results, when combined, support the conclusion that uniform azimuthal alignment of 5CB is the result of long-range ordering of polymer chains in the Langmuir films (in a preferred direction orthogonal to the direction of compression) that is generated during uniaxial compression of the films prior to LS transfer. Although past studies of Langmuir films of polymers at aqueous-air interfaces have demonstrated that in-plane alignment of polymer backbones can be induced by uniaxial compression, these past reports have generally made use of polymers with rigid backbones. One important outcome of this current study is thus the observation of anisotropy and long-range order in Langmuir films of a novel flexible polymer. A second important outcome is the observation that the existence, extent, and dynamics of this order can be identified and characterized optically by transfer of the Langmuir film to a thin film of LC. Additional characterization of Langmuir films of two other flexible polymers [poly(methyl methacrylate) and poly(vinyl stearate)] using this method also resulted in uniform azimuthal alignment of 5CB, suggesting that the generation of long-range order in uniaxially compressed Langmuir films of polymers may also occur more generally over a broader range of polymers with flexible backbones
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