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This study investigated the characteristics of subjective memory complaints (SMCs) and their association with current and future cognitive functions.
A cohort of 209 community-dwelling individuals without dementia aged 47–90 years old was recruited for this 3-year study. Participants underwent neuropsychological and clinical assessments annually. Participants were divided into SMCs and non-memory complainers (NMCs) using a single question at baseline and a memory complaints questionnaire following baseline, to evaluate differential patterns of complaints. In addition, comprehensive assessment of memory complaints was undertaken to evaluate whether severity and consistency of complaints differentially predicted cognitive function.
SMC and NMC individuals were significantly different on various features of SMCs. Greater overall severity (but not consistency) of complaints was significantly associated with current and future cognitive functioning.
SMC individuals present distinctive features of memory complaints as compared to NMCs. Further, the severity of complaints was a significant predictor of future cognition. However, SMC did not significantly predict change over time in this sample. These findings warrant further research into the specific features of SMCs that may portend subsequent neuropathological and cognitive changes when screening individuals at increased future risk of dementia.
As part of further investigations into three linked haemorrhagic fever with renal syndrome (HFRS) cases in Wales and England, 21 rats from a breeding colony in Cherwell, and three rats from a household in Cheltenham were screened for hantavirus. Hantavirus RNA was detected in either the lungs and/or kidney of 17/21 (81%) of the Cherwell rats tested, higher than previously detected by blood testing alone (7/21, 33%), and in the kidneys of all three Cheltenham rats. The partial L gene sequences obtained from 10 of the Cherwell rats and the three Cheltenham rats were identical to each other and the previously reported UK Cherwell strain. Seoul hantavirus (SEOV) RNA was detected in the heart, kidney, lung, salivary gland and spleen (but not in the liver) of an individual rat from the Cherwell colony suspected of being the source of SEOV. Serum from 20/20 of the Cherwell rats and two associated HFRS cases had high levels of SEOV-specific antibodies (by virus neutralisation). The high prevalence of SEOV in both sites and the moderately severe disease in the pet rat owners suggest that SEOV in pet rats poses a greater public health risk than previously considered.
Latest Sandbian to early Katian sequences across Laurentia's epicontinental sea exhibit a transition from lithologies characterized as ‘warm-water’ carbonates to those characterized as ‘cool-water'carbonates. This shift occurs across the regionally recognized M4/M5 sequence stratigraphic boundary and has been attributed to climatic cooling and glaciation, basin reorganization and upwelling of open ocean water, and/or increased water turbidity and terrigenous input associated with the Taconic tectophase. Documentation of oxygen isotopic trends across the M4/M5 and through bracketing strata provides a potential means of distinguishing among these alternative scenarios; however, oxygen isotopic records generated to date have failed to settle the debate. This lack of resolution is because δ18O records are open to multiple interpretations and potentially confounding factors related to local environmental conditions have not been tested by examining the critical interval in multiple areas and different depositional settings. To begin to address this shortcoming, we present new species-specific and mixed assemblage conodont δ18O values in samples spanning the M4/M5 boundary from the Upper Mississippi Valley, Alabama, and Virginia. The new results are combined with previous studies, providing a record of δ18O variability across SE Laurentia. The combined dataset allows us to test for regional trends at a resolution not previously available. Our results document a ~1.5‰ decrease in values across Laurentia instead of increasing δ18O values across the M4/M5 as predicted in various ‘cool-water’ scenarios. In short, these results do not support a shift to ‘cool-water’ conditions as an explanation for changes in early Katian carbonates across the M4/M5.
The aim of this study was to compare the dosimetric parameters and effects of simultaneous integrated boost (SIB) and traditional sequential electron boost, after helical tomotherapy, because of the lack of studies in this field in the current literature.
Computed tomographic data of 14 patients who received SIB in 2012–2015 were collected from Hong Kong Sanatorium & Hospital. New tomotherapy with SIB plans and tomotherapy with sequential boost plans were generated for each patient, and results were compared.
Conformation number, mean dose, dose received by 95% volume (both sides), ipsilateral lung volume receiving 20 Gy (V20) and skin dose (right side) were found to be significantly better for SIB (p<0·05), however coverage index and gross target volume dose showed no significant difference, and heart dose was significantly higher for SIB on the right side.
Tomotherapy with SIB may be able to offer less organ at risk dose (except for the heart), while maintaining the ability to deliver adequate dose coverage.
Carbapenem-resistant Acinetobacter baumannii (CRAB) with diverse multilocus sequence typing emerged among our nursing home residents (6.5%) with a high background rate of MRSA (32.2%). Rectal swabs yielded a higher rate of CRAB detection than axillary or nasal swabs. Bed-bound status, use of adult diapers, and nasogastric tube were risk factors for CRAB colonization.
Binocular rivalry (BR) is an intriguing phenomenon that occurs when two different images are presented, one to each eye, resulting in alternation or rivalry between the percepts. The phenomenon has been studied for nearly 200 years, with renewed and intensive investigation over recent decades. The rate of perceptual switching has long been known to vary widely between individuals but to be relatively stable within individuals. A recent twin study demonstrated that individual variation in BR rate is under substantial genetic control, a finding that also represented the first report, using a large study, of genetic contribution for any post-retinal visual processing phenomenon. The twin study had been prompted by earlier work showing BR rate was slow in the heritable psychiatric condition, bipolar disorder (BD). Together, these studies suggested that slow BR may represent an endophenotype for BD, and heralded the advent of modern clinical and genetic studies of rivalry. This new focus has coincided with rapid advances in 3D display technology, but despite such progress, specific development of technology for rivalry research has been lacking. This review therefore compares different display methods for BR research across several factors, including viewing parameters, image quality, equipment cost, compatibility with other investigative methods, subject group, and sample size, with a focus on requirements specific to large-scale clinical and genetic studies. It is intended to be a resource for investigators new to BR research, such as clinicians and geneticists, and to stimulate the development of 3D display technology for advancing interdisciplinary studies of rivalry.
The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae, and orphan afterglows of gamma-ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of 5 s and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST.
A user-friendly beam propagation program has been developed for use over the worldwide- web to aid the optical limiting community in modeling the transmission of light through nonlinear refractive and absorptive media having local intensity-dependent or nonlocal fluencedependent mechanisms.
CdTe and CdS are emerging as the most promising materials for thin film photovoltaics in the quest of the achievement of grid parity. The major challenge for the advancement of grid parity is the achievement of high quality at the same time as low fabrication cost. The present paper reports the results of the new deposition technique, Pulsed Plasma Deposition (PPD), for the growth of the CdTe layers on CdS/ZnO/quartz and quartz substrates. The PPD method allows to deposit at low temperature. The optical band gap of deposited layers is 1.50 eV, in perfect accord with the value reported in the literature for the crystalline cubic phase of the CdTe.
The films are highly crystalline with a predominant cubic phase, a random orientation of the grains of the film and have an extremely low surface roughness of 4.6±0.7 nm r.m.s.. The low roughness, compared to traditional thermal deposition methods (close space sublimation and vapour transport) permits the reduction of the active absorber and n-type semiconductor layers resulting in a dramatic reduction of material usage and the relative deposition issues like safety, deposition rate and ultimately cost
Las Cumbres Observatory Global Telescope Network (LCOGT) is currently building a new kind of general-purpose astronomical facility: a fully robotic network of telescopes of 2m, 1m and 0.4m apertures and homogeneous instrumentation. A pan-network approach to scheduling (rather than per individual telescope) offers redundancy in the event of poor weather or technical failure, as well as the ability to observe a target around the clock. Here we describe the network design and instrumentation under development, together with the main science programmes already being lead by LCOGT staff.
Background: This study investigated whether brief exposure to information has any effect on stigmatizing attitudes towards older people with dementia, and how people responded to this medical diagnosis.
Methods: 494 adults were randomly assigned to three groups differentiated by experimental conditions. Group A (control) responded to questions on stigma directly. Group B (symptom) read two vignettes that described the symptoms of two fictitious individuals with dementia, before answering questions on stigma. Group C (label) read the same vignettes which ended with a statement that the person was recently diagnosed with dementia by a physician. Data were analyzed with ANOVA, together with other pre-existing between-subjects factors.
Results: Brief exposure to information about dementia led to a statistically significant reduction in stigma (Groups B, C < A), regardless of whether the diagnostic label of “dementia” was included or not. Moreover, lower stigma was reported by persons who knew a relative or friend with dementia, who were younger and more educated, and who thought dementia was treatable.
Conclusions: As stigmatizing attitudes toward dementia are still a hindrance to early help-seeking in Asian communities, the findings suggest that community education may play a useful role in alleviating this barrier to early detection and intervention.
The trend toward smaller dimensions in integrated circuit technology presents severe physical and engineering challenges for ion implantation. These challenges, together with the need for physically-based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in silicon. Recently the DOE Council on Materials requested that our panel examine the current status and future research opportunities in the area of ion beams in semiconductor processing. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. These topics were explored both from the perspective of the emerging science issues and the technology challenges.
Capacitors, resistors and inductors are surface mounted components on circuit boards, which occupy up to 70% of the circuit board area. For selected applications, these passives are packaged inside green ceramic tape substrates and sintered at temperatures over 700°C in a co-fired process. These high temperature processes are incompatible with organic substrates, and low temperature processes are needed if passives are to be embedded into organic substrates. A new high permeability dual-phase Nickel Zinc Ferrite (DP NZF) core fabricated using a low temperature sol-gel route was developed for use in embedded inductors in organic substrates. Crystalline NZF powder was added to the sol-gel precursor of NZF. The solution was deposited onto the substrates as thin films and heat-treated at different temperatures. The changes in the microstructures were characterized using XRD and SEM. Results showed that addition of NZF powder induced low temperature transformation of the sol-gel NZF phase to high permeability phase at 250°C, which is approximately 350°C lower than transformation temperature for pure NZF sol gel films. Electrical measurements of DP NZF cored two-layered spiral inductors indicated that the inductance increased by three times compared to inductors without the DP NZF cores. From microstructural observations, the increase is correlated with the changes in microstructural connectivity of the powder phase.
We report on the fabrication and characterisation gallium nitride light emitting diodes (LEDs) grown by molecular beam epitaxy on (0001) oriented sapphire and (111)B GaAs substrates. The current voltage characteristics of the devices grown on sapphire show turn on voltages of between 4 and 5V with large on-series resistance of 600Ω; for corresponding devices grown on GaAs these parameters are between 6 and 7V and 150 Ω, respectively.
Room temperature electroluminescence (EL) spectra from the GaN LEDs ,grown on sapphire substrates, show a dominant emission at 3.2 eV (397nm) with a full width half maximum (FWHM) of 335 meV which is attributed to free electron to acceptor transitions (e, A−Mg). A broad low intensity deep level emission is also observed centred at 2.4 eV (506nm). The peak of the EL from the devices grown on GaAs is at 3.1eV rather than 3.2eV. The differences between the two sets of devices are probably caused by the different device geometry.
Preliminary results show that an “annealing” effect caused by electrical stressing resulted in an improvement of the EL spectra. The stressed samples show an increase in the near band edge emission intensity, a 20meV reduction in the FWHM and a significant reduction in the intensity of the deep level emission. The devices have a large 1/f noise contribution which does not appear to change after electrical stressing.
Boron was implanted into n-type Si at energies from 500 eV to 1 keV and doses near 1 E14 cm-2and 1E51 cm−2. Electrical activation was achieved by rapid thermal annealing (RTA) in nominally pure N−2and 0.1% 02 with the fastest available heating rates of up to 150 °C/s, cooling rates up to 80 °C/s, and included “spike” anneals with minimum dwell time at peak temperature. Measurements of sheet resistance, Hall coefficient, and secondary ion mass spectroscopy profiling were used to determine dopant activation and diffusion. Surface oxidation was studied by film thickness ellipsometry. Analyses of electrical transport measurements are used to relate junction depths to sheet resistance and their dependence on annealing temperature and time. For spike annealing, junction leakage and adequate activation limits the minimum practical temperature while diffusion limits the maximum practical temperature for formation of shallow junctions.
Brittle-to-ductile transition (BDT) temperature (TBD) was evaluated according to temperature dependence of tensile properties under different strain rates from 10−5to 10−1s−1in two-phase Ti-47Al-2Mn-2Nb and Ti-47A1–2Mn-2Nb-0.8 TiB2alloys with nearly lamellar microstructure. Based on the strain rate dependence of the determined TBD values, apparent BDT activation energies were determined using Zener-Hollomon factor. Tensile fracture surfaces were observed using a scanning electron microscope while deformation substructures were investigated by transmission electron microscopy. It was found that the BDTT of both alloys increased sharply with the strain rate and that the minor addition of 0.8 vol% TiB2reduced TBD by about 100K at the same strain rate. The TiB2addition also decreases the apparent BDT activation energy from 324 to 256 kJ/mol. Both of these values approximate to self- or inter-diffusion of Ti and Al atoms in TiAl phase. Transgranular fracture and dimple fracture were found dominant in fracture surfaces below and above TBD, respectively. The most common 1/2<110] ordinary dislocations were found to begin climb at mound TBD. All this evidence, as well as a theoretical calculation using the Nabarro Model, add up to a conclusion that the BDT is controlled by dislocation climb in both alloys.
Medium energy ion scattering (MEIS), operated at sub-nm depth resolution in the double alignment configuration, has been used to examine implant and damage depth profiles formed in Si(100) substrates irradiated with 2.5 keV As+ and 1 keV B+ ions. Samples were implanted at temperatures varying between 150°C, and 300°C to doses ranging from 3X1014 to 2X1016 cm-2. For the As implants the MEIS studies demonstrate the occurrence of effects such as a dopant accommodation linked to the growth in depth of the damage layer, dopant clustering, as well as damage and dopant movement upon annealing. Following epitaxial regrowth at 600°C, approximately half of the As was observed to be in substitutional sites, consistent with the reported formation of AsnV complexes (n≤4), while the remainder became segregated and became trapped within a narrow, 1.1 nm wide layer at the Si/oxide interface
MEIS measurements of the B implants indicate the formation of two distinct damage regions each with a different dependence on implant dose, the importance of dynamic annealing for implants at room temperature and above, and a competing point defect trapping effect at the Si/oxide interface. B+ implantation at low temperature resulted in the formation of an amorphous layer due to the drastic reduction of dynamic annealing processes.
Notably different dopant distributions were measured by SIMS in the samples implanted with As at different temperatures following rapid thermal annealing (RTA) up to 1100°C in an oxidising environment. Implant temperature dependent interactions between defects and dopants are reflected in the transient enhanced diffusion (TED) behaviour of As.