We agree with Rahnev & Denison (R&D) that to understand perception at a process level, we must investigate why performance sometimes deviates from idealised decision models. Recent research reveals that such deviations from optimality are pervasive during perceptual development. We argue that a full understanding of perception requires a model of how perceptual systems become increasingly optimised during development.

We present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.

The Detroit Lakes chain of lakes consists of five basins in northwest Minnesota adjacent to the town of Detroit Lakes. Flowering rush has been established in these basins since the 1960s. We evaluated the distribution of flowering rush in the five basins using a point intercept method, with 830 points distributed in a grid with points 150 m apart. These data were analyzed to determine whether invasive and native species frequencies were different between 2010 and 2011. We also assessed co-occurrence of flowering rush with native hardstem bulrush. The distribution of both flowering rush and hardstem bulrush was unchanged from 2010 to 2011. Flowering rush is invading areas with native plants and not establishing in unvegetated areas. Although flowering rush is found as deep as 4.5 m, it is most frequent at a depth of 1.3 m. We also examined the distribution of biomass and growth across a depth gradient from 0.3 to 3.0 m in 0.3-m intervals. At each 0.3-m interval, three biomass samples were collected at each of 10 transects for a total of 30 samples per depth interval or 300 biomass samples. At each point, leaf height, emergent leaf height, water depth, number of ramets, and number of rhizome buds were counted. Biomass samples were collected in a 0.018-m2 core sampler, sorted to shoots and belowground biomass. We found that flowering rush height and biomass peaked at 1.3 m and declined with greater depth. Bud density was negatively related to water depth. Bud density averaged 300 buds m–2, which was three times the average ramet density (100 ramets m–2).

Comprehensive characterization of materials suggests measuring their different properties for optimal use in technological applications and this task becomes more challenging as size of related structures decreases and their complexity increases. At smaller scales Atomic Force Microscopy (AFM) enables visualization of structures and quantitative measurements of their mechanical and electric properties. So far, several properties such as elastic modulus and work of adhesion, surface potential and dielectric permittivity can be extracted from the results obtained in various AFM modes. More complicated are the AFM experiments and their analysis in case of viscoelastic, piezoelectric and thermoelectric properties. Several examples of quantitative characterization of neat polymers will be given. In many cases the dissimilarity of the components’ properties is employed for their recognition in heterogeneous systems such as polymer blends, block copolymers and metal alloys. The confined geometries, which are common for small-scale structures, might restrict such identification and a combination of AFM with spectral methods such as Raman scattering will be helpful. Achievements and challenges of compositional mapping will be illustrated on several complex materials.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Guanidinoacetic acid (GAA) is the natural biosynthetic precursor of creatine, in a metabolic reaction that requires only a methyl group transfer. The use of GAA as a food additive for restoring creatine load in human tissues is rather unexplored and data on efficacy and safety are limited. In particular, an increase in serum homocysteine after GAA administration can be regarded as critical and should be prevented. The present study evaluated the effects of orally administered GAA with and without methyl group donors on serum and urine creatine concentrations, and the occurrence of adverse events during an intervention in healthy human subjects. A total of twenty male and female volunteers were randomised in a double-blind design to receive either GAA (2·4 g/d) or GAA with methyl donors (2·4 g/d of GAA and 1·6 g/d of betaine HCl, 5 μg/d of vitamin B12, 10 mg/d of vitamin B6 and 600 μg/d of folic acid) by oral administration for 8 weeks. Serum and urine creatine increased significantly from before to after administration in both groups (P< 0·001). The proportion of participants who reported minor adverse events was 33·3 % in the GAA group, and 10·0 % in the GAA with methyl donors group (P= 0·30). Hyperhomocysteinaemia was found in 55·6 % of participants supplemented with GAA, while no participant experienced hyperhomocysteinaemia in the group supplemented with GAA and methyl donors (P= 0·01). In summary, both interventions strongly influenced creatine metabolism, resulting in a significant increase in fasting serum creatine. The concomitant supplementation of methyl donors along with GAA largely precluded the elevation of serum homocysteine caused by GAA administration alone.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

In order to combine the merits of both HfO2 and Al2O3 as high-κ gate dielectrics for CMOS technology, high-κ nanolaminate structures in the form of either Al2O3/HfO2/Al2O3 or Al2O3/HfAlOx/Al2O3 were implemented in pMOSFETs and electrically and microstructurally charachterized. ALD TiN film was used as the metal gate electrodes for the pMOSFETs. After full transistor-processing including a rapid thermal processing step at 930 °C, the HfO2 film in the former nanolaminate was found to be crystallized. In contrast, the HfAlOx layer in the latter nanolaminate remained in the amorphous state. Both types of pMOSFETs exhibited a hysteresis as small as ∼20 mV in C-V characteristics in the bias range of +/− 2 V. They also showed a reduced gate leakage current. The pMOSFET with the Al2O3/HfAlOx/Al2O3 nanolaminate was characterized with a subthreshold slope of 77 mV/decade and a channel hole mobility close to the universal hole mobility curve. The pMOSFET with the Al2O3/HfO2/Al2O3, however, exhibited a subthreshold slope of 100 mV/decade and a ∼30% lower hole mobility than the universal curve.

Colour characterisation of a three-terminal three-channel colour detector in the assembly glass/TCO1/PI1NI2P/TCO2/PI3N/Al is performed, using a method of polynomial regression. The metameric errors of the detector calculated and investigated for different orders of polynomial colour correction are presented and discussed. The benefits of the first order colour correction are shown and graphically illustrated. The final transformation matrix for the first order colour correction and conversion to the output R, G and B signals is given. At the end, a demonstrational application with the a-Si:H-based detector and corresponding read-out and colour correction electronics is presented.

A novel family of three-terminal three-color (blue, green, red) detectors based on stacked a-SiC:H/a-Si:H heterostructures is presented: TCO/PIN/TCO/PINIP/TCO/metal and TCO/PINIP/TCO/PIN/TCO/metal structure. The analysis of stacked photodetectors and the optimization of their geometrical dimensions is performed using the adopted ASPIN simulation program. Both structures are mutually compared with regard to calculated current-voltage characteristics and spectral responsivity. They both exhibit linear photocurrent/generation-rate relationship for all three colors at peak wavelengths 430, 530, 630 nm, applying ±1 V or more. This linearity allows that all three colors can be detected with high rejection ratio using simple system electronics.

Based on measured characteristics of degraded p-i-n structures, simulations of degraded structures were performed using our numerical simulator ASPIN in order to fit and explain pronounced hump-shaped voltage-dependent internal collection efficiency (ICE) characteristics under weak short-wavelength illumination. Agreement with measured hump-shaped ICE characteristics was obtained only if in addition to the introduction of light-induced dangling bond defect states, their capture cross-sections were also increased, in particular capture crosssection for the charged defect states. This causes a change in occupancy of defect states at the p-i interface and front part of the i-layer under forward bias. Consequently, it increases the electric field in the front part of the cell, which results in recovery of the ICE.

The Field Emission Display (FED) is often portrayed as the emerging alternative to the Active Matrix Liquid Crystal Display (AMLCD). FED displays are based on cold cathodes that emit electrons which are accelerated across a potential in a vacuum to strike a phosphor and emit light. There are numerous material and technology choices at each point of the display system design. Each alternative is characterized by advantages and consequences that affect subsequent choices and system performance. This paper discusses the alternative approaches to cathode material and structure, electron beam focusing, support structure, phosphor and system integration. These choices are related to ultimate display performance and cost.