Philip Thomas

Self-repair in dialogues of schizophrenics: Effects of hallucinations and negative symptoms

This paper concerns the discourse features of verbal hallucinations and negative symptoms of schizophrenia. A total of 46 schizophrenics, varying in verbal hallucination and in negative symptoms status, and 22 controls were tested on the Reporter Test. The frequency with which they issued inadequate instructions, attempted to repair the inadequacies, and the success of repairs were compared. We observed that schizophrenics, on the whole, issued more wrong and incomplete instructions. This was in part related to their worse working memory, but it was not affected by verbal hallucinations or negative symptoms. We observed, further, that schizophrenics had no particular problems monitoring messages for inadequacies. We did find, however, that schizophrenics with verbal hallucinations had a specific problem with self-repairing wrong instructions. We interpret these results in the framework of Hoffmans (1986b) plan disruption-based model of verbal hallucinations; the Frith (1987) and Frith and Done (1988) internal monitoring model of positive and negative symptoms; and finally Frith and Friths (1990) model of negative and positive schizophrenia and we use the results to specify the models.

Super-narrow, extremely high quality collective plasmon resonances at telecom wavelengths and their application in a hybrid graphene-plasmonic modulator.

We present extremely narrow collective plasmon resonances observed in gold nanostripe arrays fabricated on a thin gold film, with the spectral line full width at half-maximum (fwhm) as low as 5 nm and quality factors Q reaching 300, at important fiber-optic telecommunication wavelengths around 1.5 μm. Using these resonances, we demonstrate a hybrid graphene-plasmonic modulator with the modulation depth of 20% in reflection operated by gating of a single layer graphene, the largest measured so far.

Self-monitoring in speech production: effects of verbal hallucinations and negative symptoms

This paper reports results of a study on self-monitoring in speech production. Thirty schizophrenics, varying in verbal hallucination and in negative symptoms status, and 17 controls were tested on the reporter test. The position of interruptions of the speech-flow to repair errors was used to indicate whether the detection of the errors was through monitoring of internal phonetic plans or through external acoustic feedback. We have found that the internal error detection was twice as frequent in controls as in schizophrenics. The relevance of this finding to Friths (1992) model of schizophrenia is discussed. Our conclusion is that the problem with internal monitoring of phonetic plans is common to all schizophrenics, and not just to those with verbal hallucinations.

Strong coupling of diffraction coupled plasmons and optical waveguide modes in gold stripe-dielectric nanostructures at telecom wavelengths

We propose a hybrid plasmonic device consisting of a planar dielectric waveguide covering a gold nanostripe array fabricated on a gold film and investigate its guiding properties at telecom wavelengths. The fundamental modes of a hybrid device and their dependence on the key geometric parameters are studied. A communication length of 250 μm was achieved for both the TM and TE guided modes at telecom wavelengths. Due to the difference between the TM and TE light propagation associated with the diffractive plasmon excitation, our waveguides provide polarization separation. Our results suggest a practical way of fabricating metal-nanostripes-dielectric waveguides that can be used as essential elements in optoelectronic circuits.

Metallic binary alloyed superconductors for photogenerating current from dissociated water molecules using broad light spectra

The production of hydrogen through water splitting via photocatalysis seems to be a promising and appealing pathway for clean energy conversion and storage. Here, we report for the first time that a series of metallic binary alloyed superconductors (MgB2, AlB2, NbB2, and NbSe2) can be used as a photoanode and a cathode in a photocatalyst composite for both hydrogen production and water oxidation reactions. It was found that the highly active ion binary metal-based photocatalyst can be used as a low-cost alternative to Pt for water photolysis. The metallic binary alloyed superconductors exhibit high activity toward both the oxygen and hydrogen evolution reactions in pure distil water and seawater. The combination of the two such photoanode and cathode yields a water splitting photocurrent density of around 1 mA/cm2, corresponding to a solar-to-photocurrent efficiency of 34%. The strong correlation between the superconductive temperature and the photocatalytic water splitting effectivity for investigated di...

Hybrid grapheme plasmonic waveguide modulators

The unique optical and electronic properties of graphene allow one to realize active optical devices. While several types of graphene-based photonic modulators have already been demonstrated, the potential of combining the versatility of graphene with sub-wavelength field confinement of plasmonic/metallic structures is not fully realized. Here we report fabrication and study of hybrid graphene-plasmonic modulators. We consider several types of modulators and identify the most promising one for light modulation at telecom and near-infrared. Our proof-of-concept results pave the way towards on-chip realization of efficient graphene-based active plasmonic waveguide devices for optical communications.

Health gain in schizophrenia: Current themes in theory and practice

This paper reviews recent theories of schizophrenia, biological, psychological and socio-culteral. From these, therapeutic interventions are explicated and evidence for the efficacy of these is reviewed. Patterns of service delivery are also concidered. It is argued that the management of the condition must reflect the complex diversity of its nature, particularly as regards aetiology. Areas of health gain in the condition are identified in the final section.

Graphene-based plasmonic biosensing

Surface plasmon resonance (SPR) is an established technique for label-free detection of trace amounts of adsorbents at a metal-dielectric interface [1]. In recent years much effort has been directed at increasing the detection limit of SPR [2]. Previous works [3,4] have in general focused on the use of gold nanoparticles for biosensing. The results of these studies have been promising but are limited in their potential application by the high costs associated with both nanofabrication techniques and gold itself.