Color Grouping in Space and Time: Evidence From Negative Color-Based Carryover Effects in Preview Search.

Five experiments addressed the role of color grouping in preview search (D. G. Watson & G. W. Humphreys, 1997). Experiment 1 used opposite color ratios of distractors in preview and second search displays, creating equal numbers of distractors in each color group in the final display. There was selective slowing for new targets carrying the majority color of the old items. This effect held when there was no bias in the preview and only the second search set had an uneven color ratio (Experiment 2). In Experiment 3, participants had foreknowledge of the target color, and effects were shown over and above those due to color biases. Experiment 4 demonstrated negative color carryover even when previews changed color. Experiment 5 showed reduced color carryover effects when previews were presented more briefly. Collectively, the results provide evidence for inhibitory carryover effects in preview search based on feature grouping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Helicopter maintenance error analysis: Beyond the third order of the HFACS-ME

In this paper a statistical analysis of a sample of 58 helicopter maintenance-induced safety occurrences is conducted to study helicopter accidents and incidents’ survivability and the severity distribution of such occurrences. Analysis is also carried out to identify helicopter main and sub-systems mostly exposed to maintenance errors and to determine various types of such errors. Expected inherent relations between rotorcraft components affected and types of associated maintenance errors are investigated. Human factors-based triggers of these accidents and severe incidents are explored. The concept of Specific Failures (SFs) that immediately precede each of such occurrences is introduced for more detailed representation of the last breached individual and organizational safety barriers. Root causes of these safety occurrences were then sought utilizing the Human Factors Analysis and Classification System-Maintenance Extension (HFACS-ME) taxonomy with a refined focus on its third order categories’ list. The rotorcraft characteristics influencing individuals and organizational behaviours within Maintenance, Repair and Overhaul organizations (MROs) are discussed in the light of the root cause investigation results.

Relevance to industry

The study of human reliability within helicopter maintenance industry is waited to emphasise the understanding of causes and propagation mechanisms of maintainers' errors and their consequences on the overall aviation safety. Previous works often investigated maintenance errors and their roles in promoting aviation accidents of fixed-wing aircraft; this research is investigating the case of rotorcraft.     

Simple adaptation of the Bridgman high pressure technique for use with liquid media

We present a simple novel technique to adapt a standard Bridgman cell for the use of a liquid pressure transmitting medium. The technique has been implemented in a compact cell, able to fit in a commercial Quantum Design PPMS system, and would also be easily adaptable to extreme conditions of very low temperatures or high magnetic fields. Several media have been tested and a mix of fluorinert FC84:FC87 has been shown to produce a considerable improvement over the pressure conditions in the standard steatite solid medium, while allowing a relatively easy setup procedure. For optimized hydrostatic conditions, the success rate is about 80% and the maximum pressure achieved so far is 7.1 GPa. Results are shown for the heavy fermion system YbAl(3) and for NaV(6)O(15), an insulator showing charge order.     

(p,T,H) Phase Diagram of Heavy Fermion Systems: Some Systematics and Some Surprises from Ytterbium

Pressure is the cleanest way to tune heavy fermion systems to a quantum phase transition in order to study the rich physics and competing phases, and the comparison between ytterbium and cerium systems is particularly fruitful. We briefly review the mechanisms in play and show some examples of expected and unexpected behaviour. We emphasise the importance of the valence changes under pressure and show how modern synchrotron techniques can accurately determine this, including at low temperature.     

Attitudes toward intimate partner violence in dating relationships.

Prevention of intimate partner violence on college campuses includes programs designed to change attitudes, and hence, a scale that assesses such attitudes is needed. Study 1 (N = 859) cross validates the factor structure of the Intimate Partner Violence Attitude Scale-Revised using exploratory factor analysis and presents initial validity data on the scale. In Study 2 (N = 687), the obtained three-factor structure (Abuse, Control, Violence) is tested using confirmatory factor analysis, and it is shown to be concurrently related to assault in romantic relationships and to predict psychological aggression 14 weeks later. The findings are discussed in the context of how understanding and modifying attitudes assessed by the Intimate Partner Violence Attitude Scale-Revised may improve interventions aimed at reducing intimate partner violence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimal choice of test signals for linear channel estimation using second order statistics

A time-varying acoustic channel may be estimated by an appropriate inference using the output from a periodic test signal. In this paper it is shown how to do this in a way that takes full account of the past history of the background noise and the past history of the channel. An explicit formula is obtained for the optimal linear estimator that may be used for rapid channel estimation for a given test signal when we know the autocovariance or power spectrum of the interfering noise and the autocovariance of the echo channel variation. Given this closed formula for the optimal estimator of the channel impulse response, an efficient method for determining the optimal test signal, subject to a constraint on the test signal power, given the history of the channel and the noise, is developed. We show that if the second order statistics of the channel or the noise are known, then the optimal test signal is not white. The method includes an explicit formula for the optimal test signal given a fixed estimator. A model of channel variation which is realistic while having less complexity than a full second-order statistical model, and therefore is more amenable to robust estimation, is used in the experiments which illustrate the performance of the optimal test signals and the channel estimation method. Matrix calculus identities required for the derivation of this expression for the optimal estimator are stated and proved in the Appendixes 1 and 2.     

Scaling properties of the anisotropic critical current density in bulk textured YBaCuO. Evidence toward a 3D flux line lattice

We have measured dc transport critical current densities of melt texture grown and magnetically melt textured bulk YBaCuO at 77 K and in magnetic field. A maximum value of over 31,000 A/cm² is obtained with a field of 7 teslas applied parallel to the (a, b) planes. Over the rest of the angular range the critical current is shown to be determined mainly by thec-axis component of the applied field. Although this dependency is expected in the presence of two-dimensional vortices, in fact the data are shown to correspond better to the behavior expected of an anisotropic three-dimensional superconductor. These results are compared to magnetization measurements on the same samples. We show that when the field is directed close to the c-axis, superconducting transport currents flow at fields well above the field at which the irreversible magnetization disappears.     

p53/E1b58kDa complex regulates adenovirus replication

We have explored a role for the adenovirus (Ad5) E1b58kDa/p53 protein complex in adenovirus replication. This was done by using virus mutants containing different defects in the E1b58kDa gene and cell lines that express either a wild-type p53 protein or a mutant p53 protein. We find that infection of wild-type p53-containing cells with wild-type Ad5 causes a shutoff of p53 and alpha-actin protein synthesis by distinct mechanisms, but neither occurs in mutant p53 cells. Our data also indicate that the shutoff is dependent on formation of the p53/E1b complex and may also involve another virus protein, E4ORF6. Following from these observations we asked whether failure to form the complex resulted in impaired adenovirus replication. Our experiments showed that neither wild-type Ad5 nor the E1b mutant dl338 could replicate in cells expressing a mutant p53 protein, but that wild-type adenovirus replicated well in wild-type p53-expressing cells. Collectively, our data suggest that the interaction between p53 and the E1b58kDa protein is necessary for efficient adenovirus replication. This is the first time such a direct link between the complex and virus replication has been demonstrated. These data raise serious questions about the usefulness of E1b-defective viruses in tumor therapy.     

Structure of human values: Testing the adequacy of the Rokeach Value Survey.

Examined the extent to which the 36 items of the Rokeach Value Survey (RVS) provide comprehensive and representative coverage of the value domain in 2 experiments. In Exp I, intensive semistructured interviews, based on the RVS, were conducted with 73 adults drawn from an electoral roll. Test–retest reliabilities were examined over 4 wks with 208 university students. In Exp II, factor structure was explored with 483 adults from the general population and with 688 university students. All Ss completed inventories of goal values, mode values, and social values. Data provide qualified support for the comprehensiveness of the instrument. The major weaknesses in sampling involved the facets of physical well-being and individual rights. Other areas not represented were thriftiness and carefreeness. The need for multi-item indices for value constructs is discussed, as are the advantages of a rating procedure over a ranking procedure from both psychometric and empirically valid perspective. An alternative instrument based on the work of Rokeach is proposed. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)