Age-relevance of person characteristics: Persons' beliefs about developmental change across the lifespan.

The authors investigated normative beliefs about personality development. Young, middle-aged, and older adults indicated the age-relevance of 835 French adjectives by specifying person characteristics as typical for any age decade from 0 to 99 years. With this paradigm, the authors determined age-relevance (How typical is a characteristic for a given age decade?). Most characteristics were ascribed to young adulthood. The pattern differed across the lifespan, however, for positive and negative person characteristics as well as for physical, cognitive, and personal/expressive characteristics. Whereas the total number of ascribed positive characteristics peaked in young adulthood and declined thereafter, the number of ascribed negative person characteristics peaked during adolescence, remained fairly low during middle adulthood, and increased slightly in old age (70+ years). As a consequence, the most positive profile was ascribed to young olds (60 to 69 years), whereas the most negative personality profiles were ascribed to the oldest age groups (70+ years) and to adolescence (10 to 19 years). The negative profiles are primarily due to more negative physical characteristics ascribed to older adults and more negative cognitive characteristics ascribed to adolescence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

In Situ Neutron Powder Diffraction Study of Ti3SiC2 Synthesis

The synthesis of Ti₃SiC₂ by pressureless reactive sintering of Ti/SiC/C mixtures under an Ar atmosphere has been studied using in situ neutron diffraction. The intermediate phases TiC_x and Ti₅Si₃C_x (x≤ 1) form first at ∼800–1400°C. These phases are consumed in the formation of Ti₃SiC₂, at ∼1500°C. After sintering, Ti₅Si₃C_x disappears but an amount of TiC_x remains in the sample primarily as a surface layer. The studies appear to support a suggestion that the intermediate phases react to form Ti₃SiC₂ through a diffusion-controlled process. Prolonged stepwise heating under argon in some experiments resulted in decomposition of Ti₃SiC₂ above ∼1400°C and significant disproportionation of the sample.     

Minimal compression of ultrathin sections with use of an oscillating diamond knife

With the aim to minimize compression artefacts in ultrathin sections, coincident with the stroke direction, we have invented an oscillating diamond knife. Results and theoretical considerations explaining its function are discussed. During conventional ultrathin sectioning the resultant compression is in the order of 20–35% of section height. This holds true for sections of samples embedded into Lowicryl HM20 and of the polymer polystyrene, cut with a 45° diamond knife and floated on water. The oscillating knife reduces this compression almost completely. It consists of a diamond knife on which a low voltage piezoelectric translator (piezo) is mounted, which oscillates when the piezo is driven by an alternating voltage source. No additional cutting artefacts were observed in the micrographs when they were compared with sections produced without oscillating the knife.     

Step size adjustment and extrapolation for time‐stepping schemes in non‐smooth dynamics

In this paper we use step size adjustment and extrapolation methods to improve Moreau's time‐stepping scheme for the numerical integration of non‐smooth mechanical systems, i.e. systems with impact and friction. The scheme yields a system of inclusions, which is transformed into a system of projective equations. These equations are solved iteratively. Switching points are time instants for which the structure of the mechanical system changes, for example, time instants for which a sticking friction element begins to slide. We show how switching points can be localized and how these points can be resolved by choosing a minimal step size. In order to improve the integration of non‐smooth systems in the smooth parts, we show how the time‐stepping method can be used as a base integration scheme for extrapolation methods, which allow for an increase in the integration order. Switching points are processed by a small time step, while time intervals during which the structure of the system does not change are computed with a larger step size and improved integration order. The overall algorithm, which consists of a time‐stepping module, an extrapolation module and a step size adjustment module, is discussed in detail and some examples are given. Copyright © 2008 John Wiley & Sons, Ltd.     

GPU Acceleration of a Configurable N-Way MIMO Detector for Wireless Systems

Multiple-input multiple-output (MIMO) wireless is an enabling technology for high spectral efficiency and has been adopted in many modern wireless communication standards, such as 3GPP-LTE and IEEE 802.11n. However, (optimal) maximum a-posteriori (MAP) detection suffers from excessively high computational complexity, which prevents its deployment in practical systems. Hence, many algorithms have been proposed in the literature that trade-off performance versus detection complexity. In this paper, we propose a flexible N-Way MIMO detector that achieves excellent error-rate performance and high throughput on graphics processing units (GPUs). The proposed detector includes the required QR decomposition step and a tree-search detector, which exploits the massive parallelism available in GPUs. The proposed algorithm performs multiple tree searches in parallel, which leads to excellent error-rate performance at low computational complexity on different GPU architectures, such as Nvidia Fermi and Kepler. We highlight the flexibility of the proposed detector and demonstrate that it achieves higher throughput than existing GPU-based MIMO detectors while achieving the same or better error-rate performance.     

An Efficient and Fair Strategy for Radio Resources Allocation in Multi-radio Wireless Mesh Networks

A Load and Interference aware Resource Allocation strategy (LIRA) is proposed for multi-radio Wireless Mesh Networks (WMNs), combining multiple mechanisms that efficiently optimise radio resources (rate, power and channel) to guarantee max–min fair capacity to every aggregating Mesh Access Point (MAP). LIRA is composed of a rate adaptation and power control mechanism, sensitive to the fat-tree traffic specificities of WMNs, using the highest bit rates at MAP gateways and using, for the ramified links, the minimum ones that satisfy their capacity needs. This enables to efficiently reduce the transmitted power and interference, advantageous for channel reutilisation. LIRA also integrates a load and interference aware channel assignment mechanism, allowing the simultaneous operation of all links without interference. When this is not achievable, two auxiliary mechanisms of channel sharing and interference-free channel reuse can be sub-sequentially used, reducing the capacity of certain MAPs to guarantee fairness to all nodes. LIRA’s gateway flow-control mechanism guarantees that all MAPs respect the allocated capacity, guaranteeing that every MAP is able to operate at its max–min fair capacity. The performance of LIRA is evaluated through simulation, considering IEEE 802.11a. For a classical hexagonal deployment of 19 MAPs with an Internet gateway, it is shown how with only 5 channels LIRA guarantees to every MAP a max–min fair capacity of 3.2 Mbit/s, without packet loss, and delay below 6 ms. It guarantees a max–min fair throughput to every MAP, having a capacity usage efficiency of 66.7 %, an energy efficiency of 26.5 Mbit/J and spectrum efficiency of 0.58 bit/s/Hz. For a more challenging scenario with 27 MAPs and 4 gateways, it is shown how LIRA uses its mechanisms in heterogeneous conditions to also guarantee max–min fair throughput to every MAP, between 5 and 11 Mbit/s, without packet loss, and a delay below 12 ms. Any system improvement will enable to reach higher WMN performance levels using the proposed strategy.     

Quantitative competitive PCR for the detection of genetically modified organisms in food

Present polymerase chain reaction (PCR) detection methods only allow the qualitative detection of GMO in food without quantitation of the GMO content. Clearly, the availability of quantitative detection methods for GMO analysis is an important prerequisite for the introduction of threshold limits for GMOs in food. PCR is well known to be quantitative if internal DNA standards are co-amplified together with the target DNA. This quantitative competitive (QC) PCR was first described in the early nineties and is widely used nowadays.

We have developed and evaluated QC–PCR systems for the quantitative detection of Roundup Ready^TM soybean (RRS) and Maximizer maize (MM) in food samples. Three DNA fragments differing from the GMO specific sequences by DNA insertions were constructed and used as internal standards in QC–PCR. These standards were calibrated by co-amplifying with mixtures containing defined amounts of RRS DNA and MM DNA, respectively. The calibrated QC–PCR systems were applied to several commercial food samples containing RRS and to three certified RRS flour mixtures (Fluka standards). Recently, quantitative methods for the detection of RRS were successfully tested in a collaborative study involving twelve European control laboratories. Thus, QC–PCR methods will allow to survey “de minimis thresholds” of GMOs in food.     

International standard problem on containment thermal–hydraulics ISP47: Step 1—Results from the MISTRA exercise

The understanding of hydrogen distribution during severe accidents in a nuclear reactor containment is still an open issue. Several containment thermal–hydraulics international standard problems (ISP) have been conducted to address this topic. However, the predictions made by the available lumped parameter or CFD computer codes were generally not satisfactory. Therefore, a new exercise was launched in 1999 using new state-of-the-art experimental facilities TOSQAN, MISTRA and ThAI that included sophisticated 3D instrumentation and well-controlled boundary conditions. Predictive capabilities of important and still uncertain phenomena such as wall condensation, natural circulation and gas stratification are assessed. In addition, comparison between lumped parameter (LP) and CFD codes and assessment of the capability of CFD codes to deal with scaling effects are performed. This article reports on the part of the exercise which concerns the MISTRA facility including experimental results and blind benchmark exercises.     

Modulating the hydroxylamine accumulation in the hydrogenation of substituted nitroarenes using vanadium-promoted RNi catalysts

The effect of vanadium promotion of Raney nickel on aryl hydroxylamine accumulation in the catalytic hydrogenation of electron deficient aromatic nitro compounds was investigated. High accumulation of 70–80% was observed with unmodified Raney nickel. Vanadium promoters were able to modulate the accumulation and depending on the modifier used, an increase (up to 86%) or a decrease (down to 11%) was found. Higher rates were obtained in the former (up to a factor 1.3), lower ones in the latter case (down to a factor 0.1) compared to the unmodified system. Supported or unsupported NH₄VO₃ was usually the most efficient modifier for obtaining low accumulation and reasonable rates, but the optimum concentration and modification procedure had to be determined for every substrate separately. In cases of low accumulation, the vanadium promoters worked as disproportionation catalysts. Dehalogenation was not significantly influenced by the presence of promoters: in all cases dehalogenation took only place after both the nitro arene and aryl hydroxylamine compound had been consumed completely. This revised version was published online in June 2006 with corrections to the Cover Date.     

Anisotropy-independent through micromachining of quartz resonatorsby ion track etching

A method to achieve deep and crystal cut-independent structuring of arbitrary lateral geometry in single crystalline quartz is demonstrated. It is based on local etching of the latent track-induced anisotropy resulting from heavy ion bombardment, and is close to independent of crystallographic orientation. Previous results are briefly reviewed and a more systematic and thorough study is presented. Miniature tuning fork structures of various sizes and directions have been realized, and the suitability for frequency control device production is discussed