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A range of endophenotypes characterise psychosis, however there has been limited work understanding if and how they are inter-related.
This multi-centre study includes 8754 participants: 2212 people with a psychotic disorder, 1487 unaffected relatives of probands, and 5055 healthy controls. We investigated cognition [digit span (N = 3127), block design (N = 5491), and the Rey Auditory Verbal Learning Test (N = 3543)], electrophysiology [P300 amplitude and latency (N = 1102)], and neuroanatomy [lateral ventricular volume (N = 1721)]. We used linear regression to assess the interrelationships between endophenotypes.
The P300 amplitude and latency were not associated (regression coef. −0.06, 95% CI −0.12 to 0.01, p = 0.060), and P300 amplitude was positively associated with block design (coef. 0.19, 95% CI 0.10–0.28, p < 0.001). There was no evidence of associations between lateral ventricular volume and the other measures (all p > 0.38). All the cognitive endophenotypes were associated with each other in the expected directions (all p < 0.001). Lastly, the relationships between pairs of endophenotypes were consistent in all three participant groups, differing for some of the cognitive pairings only in the strengths of the relationships.
The P300 amplitude and latency are independent endophenotypes; the former indexing spatial visualisation and working memory, and the latter is hypothesised to index basic processing speed. Individuals with psychotic illnesses, their unaffected relatives, and healthy controls all show similar patterns of associations between endophenotypes, endorsing the theory of a continuum of psychosis liability across the population.
A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.
We present results from a multiwavelength study of the blazar PKS 1954–388 at radio, UV, X-ray, and gamma-ray energies. A RadioAstron observation at 1.66 GHz in June 2012 resulted in the detection of interferometric fringes on baselines of 6.2 Earth-diameters. This suggests a source frame brightness temperature of greater than 2 × 1012 K, well in excess of both equipartition and inverse Compton limits and implying the existence of Doppler boosting in the core. An 8.4-GHz TANAMI VLBI image, made less than a month after the RadioAstron observations, is consistent with a previously reported superluminal motion for a jet component. Flux density monitoring with the Australia Telescope Compact Array confirms previous evidence for long-term variability that increases with observing frequency. A search for more rapid variability revealed no evidence for significant day-scale flux density variation. The ATCA light-curve reveals a strong radio flare beginning in late 2013, which peaks higher, and earlier, at higher frequencies. Comparison with the Fermi gamma-ray light-curve indicates this followed ~ 9 months after the start of a prolonged gamma-ray high-state—a radio lag comparable to that seen in other blazars. The multiwavelength data are combined to derive a Spectral Energy Distribution, which is fitted by a one-zone synchrotron-self-Compton (SSC) model with the addition of external Compton (EC) emission.
The Herschel Space Observatory was the fourth cornerstone mission in the European Space Agency (ESA) science programme with excellent broad band imaging capabilities in the sub-mm and far-infrared part of the spectrum. Although the spacecraft finished its observations in 2013, it left a large legacy dataset that is far from having been fully scrutinised and still has a large potential for new scientific discoveries. This is specifically true for the photometric observations of the PACS and SPIRE instruments. Some source catalogues have already been produced by individual observing programs, but there are many observations that risk to remain unexplored. To maximise the science return of the SPIRE and PACS data sets, we are in the process of building the Herschel Point Source Catalogue (HPSC) from all primary and parallel mode observations. Our homogeneous source extraction enables a systematic and unbiased comparison of sensitivity across the different Herschel fields that single programs will generally not be able to provide. The catalogue will be made available online through archives like the Herschel Science Archive (HSA), the Infrared Science Archive (IRSA), and the Strasbourg Astronomical Data Center (CDS).
Structural brain measures are employed as endophenotypes in the search for schizophrenia susceptibility genes. We analyzed two independent structural imaging datasets with voxel-based morphometry and with source-based morphometry, a multivariate, independent components analysis, to determine the stability and heritability of regional gray matter concentration abnormalities in schizophrenia. The samples comprised 209 and 102 patients with schizophrenia and 208 and 96 healthy volunteers, respectively. The second sample additionally included non-ill siblings of participants with and without schizophrenia. A standard voxel-based analysis showed reproducible regional gray matter deficits in the affected participants compared with unrelated, unaffected controls in both datasets: patients showed significant gray matter concentration deficits in cortical frontal, temporal, and insular lobes. Source-based morphometry (SBM) was applied to the gray matter images of the entire sample to determine the effects of diagnosis on networks of covarying structures. The SBM analysis extracted 24 significant sets of covarying regions (components). Four of these components showed significantly lower gray matter concentrations in patients (p < .05). We determined the familiality of the observed SBM components based on 66 sibling pairs (25 discordant for schizophrenia). Two components, one including the medial frontal, insular, inferior frontal, and temporal lobes, and the other including the posterior occipital lobe, showed significant familiality (p < .05). We conclude that structural brain deficits in schizophrenia are replicable, and that SBM can extract unique familial and likely heritable components. SBM provides a useful data reduction technique that can provide measures that may serve as endophenotypes for schizophrenia.
Our team has been investigating the use of particle-based contacts in CdTe solar cell technologies. Toward this end, particles of Cu-doped HgTe (Hg-Cu-Te) and Sb-Te have been applied as contacts to CdTe/CdS/SnO2 heterostructures. These metal telluride materials were characterized by standard methods. Hg-Cu-Te particles in graphite electrodag contacts produced CdTe solar cells with efficiencies above 12% and series resistance (Rse) of 6 Ω or less. Metathesis preparation of Cu(I) and Cu(II) tellurides (i.e., Cu2Te and CuTe, respectively) were attempted as a means of characterizing the valence state of Cu in the Hg-Cu-Te ink. For Sb-Te contacts to CdTe, open circuit voltages (Vocs) in excess of 800 mV were observed, however, efficiencies were limited to 9%; perhaps a consequence of the marked increase in the Rse (i.e., >20 Ω) in these non-graphite containing contacts. Acetylene black was mixed into the methanolic Sb-Te colloid as a means of reducing Rse, however, no improvement in device properties was observed.
The use of nanoparticle precursors for electronic materials including sulfides, selenides, oxides and the elements has potentially wide ranging implications for improving device properties and substantially reducing the deposition costs. To realize this goal the complex interfacial chemistry of these small particles must be controlled. In this paper we present a number of cases demonstrating the complexity of this chemistry. These include CuInSe2 where the kinetics of phase formation dominate the sintering process; CdTe where sintering proceeds with and without the sintering enhancement of CdCl2, but produces materials different electronically than bulk materials; and the use of compound and elemental nanoparticles ( Ag, Al, Hg-Cu-Te and Sb-Te) for contacts to elemental and compound semiconductors (Si and CdTe).
Previous studies have suggested that motivational aspects of executive functioning, which may be disrupted in schizophrenia patients with negative symptoms, are mediated in part by the striatum. Negative symptoms have been linked to impaired recruitment of both the striatum and the dorsolateral prefrontal cortex (DLPFC). Here we tested the hypothesis that negative symptoms are associated primarily with striatal dysfunction, using functional magnetic resonance imaging (fMRI).
Working-memory load-dependent activation and gray matter volumes of the striatum and DLPFC were measured using a region-of-interest (ROI) approach, in 147 schizophrenia patients and 160 healthy controls. In addition to testing for a linear relationships between striatal function and negative symptoms, we chose a second, categorical analytic strategy in which we compared three demographically and behaviorally matched subgroups: patients with a high burden of negative symptoms, patients with minimal negative symptoms, and healthy subjects.
There were no differences in striatal response magnitudes between schizophrenia patients and healthy controls, but right DLPFC activity was higher in patients than in controls. Negative symptoms were inversely associated with striatal, but not DLPFC, activity. In addition, patients with a high burden of negative symptoms exhibited significantly lower bilateral striatal, but not DLPFC, activation than schizophrenia patients with minimal negative symptoms. Working memory performance, antipsychotic exposure and changes in gray matter volumes did not account for these differences.
These data provide further evidence for a robust association between negative symptoms and diminished striatal activity. Future work will determine whether low striatal activity in schizophrenia patients could serve as a reliable biomarker for negative symptoms.
Metal-organic and hybrid metal-organic/metal nanoparticle inkswere evaluated for use in the inkjet printing of copper and silver conducting lines. Pure, smooth, dense, highly conductive coatings were produced by spray printing with (hexafluoroacetylacetonato)copper(I)-vinyltrimethylsilane Cu(hfa)·VTMS) and (hexafluoroacetylacetonato)silver(I)(1,5-cyclooctadiene) (Ag(hfa)COD) metal-organic precursors on heated substrates. Good adhesion to the substrates tested, glass, Kapton tape and Si, has been achieved without use of adhesion promoters. The silver metal-organic ink has also beenused to print metal lines and patterns with a commercial inkjet printer. Hybrid inks comprised of metal nanoparticles mixed with the metal-organic complexes above have also been used to deposit Cu and Ag films by spray printing.This approach gives dense, adherent films that are much thicker than those obtained using the metal-organic inks alone. The conductivities of the silvercoatings obtained by both approaches are near that of bulk silver (2 μΩ·cm). The copper coatings had conductivities at least an order ofmagnitude less than bulk.
Dry etching of silver for the metallization in microelectronics is
investigated. Etching is performed using an electron-cyclotron-resonance
reactive-ion-beam-etching system (ECR-RIBE) in an Ar/CF4 or
Ar/CF4/O2 mixture. The etch characteristics are
strongly affected by ion energy (beam voltage and microwave energy); the
O2 concentration in the reactive mixture has only a small
effect. An anisotropic, smooth etch profile and clean surface are obtained.
Focused ion beam (FIB) and atomic force microscopy (AFM) have been used to
study the etched profile and the roughness, respectively.
The application of porous low-k interlayer dielectrics is needed for
reducing the parasitical capacitance, especially at 65-nm node and beyond.
The understanding of process-induced modifications to material properties is
crucial for a successful integration of these low-k dielectrics. The dry
etching processes of porous low-k materials are important modules in ULSI
fabrication. In this study, the interaction between MSQ-based JSR LKD-5109
films (shown by PALS to have interconnected 2.8 nm size pores) with
CF4/O2 plasma has been investigated. Various ratios of
O2 content were designed to characterize its effects on the
etch rate, formation of polymerization layer, and properties of the LKD-5109
film. Composition analysis was conducted by SIMS and FTIR. Moisture
absorption and fluorine diffusion into low-k films after etch process are
observed, along with carbon depletion near the surface region. The influence
of etching chemistries on the morphological characteristics of thin Ta
barrier layers (8-nm in thickness) deposited on etched low-k films were
further investigated by SEM, and it is found that oxygen concentration has
significant influences on the morphological characteristics of thin Ta
Ultra low dielectric constant (κ) material is needed as the inter-metal
dielectrics to reduce RC delay when device dimension is scaled to sub-100nm.
Porous dielectric films have been considered as good candidates for the
application as inter-metal dielectrics due to their ultra low-k properties.
Identifying proper dielectric copper diffusion barrier on the porous low-k
films is critical for the low-k/Cu damascene fabrication process. In this
study, we have evaluated the compatibility of plasma-deposited amorphous
Boron Nitride film as a dielectrics copper diffusion barrier on a MSQ-based
porous low-k LKD5109 film (from JSR). Both microwave plasma enhanced CVD
(2.45 GHz) and radio-frequency plasma enhanced CVD (13.56 MHz) were applied
for the BN deposition in order to evaluate the compatibility of the two
plasma processes with the porous film. Growth parameters were optimized to
minimize the boron diffusion and carbon depletion in the porous low-k films,
which were found to have deleterious effects on the dielectric properties of
the low-k films. FTIR and micro-Raman were employed for analyzing the
changes in chemical structure of the low-k films after BN growth.
Capacitance-voltage measurement was used to characterize the dielectric
constants of BN film on Si and the BN-deposited porous low-k film. SIMS
characterization was carried out to evaluate the performance of the BN film
against copper diffusion.
The physical and electrical properties as well as thermal stability of
reactively sputtered titanium nitride (TiN) film serving as a diffusion
barrier was studied for silver (Ag) metallization. The thermal stability of
Ag/TiN metallizations on Si with 12-nm-thick TiN barriers, as-deposited and
after annealing at 300-650°C in N2/H2 for 30 min, was
investigated with sheet resistance measurement, X-ray diffraction, focused
ion beam-scanning electron microscopy, atomic force microscopy and X-ray
photoelectron spectroscopy. According to electrical measurement no change of
sheet resistance was found after annealing at 600°C, but an abrupt rise
appeared at 650°C annealing. There are two causes by which the Ag/TiN/Si
structure became degraded. One is agglomeration of the silver layer, and the
other is oxidation and diffusion which are also associated problems during
-Heteroepitaxial superconducting Bi,Sr2CaCu2Ox (BSCCO 2212) thin films have been formed by solid phase epitaxy from amorphous films deposited on (100) LaA1O3 single crystal substrates by organometallic chemical vapor deposition. The epitaxial structure of the film is confirmed by x-ray diffraction including θ/2θ and Φ (in plane rotation) scans. Cross-sectional high resolution transmission electron microscopy indicates that the film-substrate interface is nearly atomically abrupt. Improvements in superconducting properties of the epitaxial thin films are noted in comparison to highly textured films deposited on MgO.
This paper provides an overview of waste glass alteration. Emphasis is on the evolution of surface layers and factors affecting the alteration rate when glass is subjected to an aqueous environment. The extent, type and rate of alteration is determined by a variety of parameters including time, temperature, glass composition, pH, Eh, composition of leachate/geology, the presence of other engineered barriers, flow conditions and surface area/volume ratio. Models (based on kinetic and thermodynamic considerations) developed by other researchers that are consistent with the experimental observations from the laboratory and field experiments are discussed. The morphology of the surface layers as described by interpretation of secondary ion mass spectrometry (SIMS) analyses on waste glasses and the role the various layers play in the alteration process is presented as well.
Microwave energy for processing materials is emerging as a vital manufacturing technology for the nineties and beyond. Research to date has shown significant advantages in several areas, including drying and sintering, joining, surface modification and waste remediation. Increased processing rates, improved physical and mechanical properties and, in some cases, reduced hazardous emissions have sparked the interest of many manufacturers in the ability to integrate microwave processing techniques into existing and future manufacturing operations. This presentation will provide an overview of the microwave processing research and development work in progress at the University of Florida.
CdS, ZnS or PbS dispersions are prepared in a NaX matrix by ion exchange and gas phase sulfidation. The degree of sulfidation remains incomplete in all cases. This fact can be explained by preferential bonding of the cations to the zeolite framework and to an increase of the solubility constants for quantum-size particles. Zeolite-hosted sulfide particles grow to supra-supercage size under fragmentation of the host framework. The shift of the position of the optical absorption edge correlates with the sulfide particle size obtained from transmission electron micrographs. The rate of photocorrosion of the sulfide clusters strongly depends on the particle size between 1 and 10 nm.
Results of research on the use of microwave energy for several waste remediation applications are discussed. Studies include; processing of simulated nuclear waste glass frits, the destruction/vitrification of electronic circuitry from commercial and defense applications, the decomposition of organic compounds and the possible use of microwave energy in off-gassing operations during the ashing of electronic circuitry. Results of leach tests on simulated nuclear waste glass are presented as well as results from preliminary tests on organic wastes.