A construct-driven investigation of gender differences in a leadership-role assessment center.

This study examined gender differences in a large-scale assessment center for officer entry in the British Army. Subgroup differences were investigated for a sample of 1,857 candidates: 1,594 men and 263 women. A construct-driven approach was chosen (a) by examining gender differences at the construct level, (b) by formulating a priori hypotheses about which constructs would be susceptible to gender effects, and (c) by using both effect size statistics and latent mean analyses to investigate gender differences in assessment center ratings. Results showed that female candidates were rated notably higher on constructs reflecting an interpersonally oriented leadership style (i.e., oral communication and interaction) and on drive and determination. These results are discussed in light of role congruity theory and of the advantages of using latent mean analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficient Protection in MPλS Networks Using Backup Trees: Part One—Concepts and Heuristics

Multi-protocol lambda switching (MPS) has recently been applied in the optical network control plane to provide fast lightpath provisioning. As an increasing amount of traffic is carried in optical transport networks (OTNs), single network failures can affect a vast amount of traffic, making lightpath protection crucial. Therefore, shared backup tree (BT) lightpath protection is a promising paradigm in MPS networks due to its ability of fast recovery and its efficiency in consumed resources. A shared BT is used to protect a group of working lightpaths towards the same destination. From the working lightpaths in such a group, only one affected lightpath at a time can be recovered using the BT. The main problem is how to group and route the working paths (WPs) and how to route the BTs, in such a way that the capacity resources used by the WPs and the BTs are minimized. In Part One of this study (presented in this paper), we propose three approaches to cope with this problem. The first approach is a purely integer linear programming (ILP) based method. The second one is a combination of ILP and a heuristic technique. The last one is a purely heuristic approach. In this paper, these approaches are theoretically compared. In Part Two [1] of this study, several simulations are carried out in order to compare these approaches in terms of performance and computing effort. The experimental results are in line with the theoretical expectations.     

Co-creation and user-generated content–elderly people’s user requirements

There is an increasing demand on citizens to participate in social network websites and to create and share their own user-generated content (UGC), such as photographs, videos, and blogs. So far, little is known about how elderly people respond to these new trends and master the techniques required. This paper reports on three studies that investigated elderly people’s user requirements related to consumption, sharing and co-creation of UGC in new media. The first study, conducted in Norway, identifies patterns of Internet usage, age differences, and participation in online communities and the consumption, sharing and co-creation of UGC on a macro level. The second study, conducted in Belgium, investigated the social requirements of elderly people on a group level. The third study, also conducted in Belgium, investigated user and context requirements on an individual level. The results of the first study show that the elderly rarely participate in online communities and share audio-visual UGC. However, they embrace some aspects of the new media and more often express themselves politically. The results of the second study show that the elderly are very motivated to contribute with UGC, given the right circumstances. The results of the third study show that it is important for elderly people that they be able to use the new technologies easily and identifies their worries about using them.     

Poly(methyl vinyl ether-b-octadecyl vinyl ether): a new non-ionic surfactant

Block copolymers consisting of methyl vinyl ether (MeVE) units and octadecyl vinyl ether (ODVE) units were synthesized using the cationic living polymerization technique. The polymerization of MeVE was initiated with the trimethyl silyl iodide/1,1-diethoxyethane/ZnI₂ system at −40°C in toluene and the living polymer thus obtained was used as initiator for the polymerization of ODVE at 07deg;C. The combination of hydrophilic (PMeVE) and hydrophobic (PODVE) segments provides the block copolymers with non-ionic surfactant properties, which have been evaluated by measurement of the stabilities of water–decane emulsions.     

Trying to understand the different pieces of the construct validity puzzle of assessment centers: An examination of assessor and assessee effects.

This study examined the effects of assessor-related factors (i.e., type of assessor) and assessee-related factors (i.e., type of assessee profile) on the construct validity of assessment center ratings. In particular, 3 types of assessors (26 industrial/organizational [I/O] psychologists, 20 managers, and 27 students), rated assessee performances that varied according to cross-exercise consistency (i.e., relatively inconsistent vs relatively consistent) and dimension differentiation (relatively undifferentiated vs relatively differentiated). Construct validity evidence was established for only 1 assessee profile and only in the I/O psychologist and managerial samples. More generally, these results indicate that 3 factors (poor design, assessor unreliability, and especially cross-situational inconsistent assessee performances) may explain why construct validity evidence is often not established in operational assessment centers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive selection of apoptosis-resistant cells correlates with activation of dominant-negative STAT5

The STAT5 activation has important roles in cell differentiation, cell cycle control, and development. However, the potential implications of STAT5 in the control of apoptosis remain unexplored. To evaluate any possible link between the erythropoietin receptor (EpoR) JAK2/STAT5 transduction pathway and apoptosis, we have investigated apoptosis-resistant cells (ApoR) that arose from positive selection of the erythroid-committed Ba/F3EpoR cells triggered to apoptosis by ectopic expression of the HOX-B8 homeotic gene. We show that JAK2 is normally activated by Epo in both Ba/F3EpoR and ApoR cells. In contrast, both STAT5a and STAT5b isoforms are uniquely activated in a C-truncated form (86 kDa) only in ApoR cells. Analysis of ApoR and Ba/F3EpoR subclones confirmed that the switch to the truncated STAT5 isoform coincides with apoptosis survival and that ApoR do not derive from preexisting cells with a shortened STAT5. In addition, ApoR cells die in the absence of Epo. This indicates that resistance to apoptosis is not because of a general defect in the apoptotic pathway of ApoR cells. Furthermore, we show that the 86-kDa STAT5 protein presents a dominant-negative (DN) character. We hypothesize that the switch to a DN STAT5 may be part of a mechanism that allows ApoR cells to be selectively advantaged during apoptosis. In conclusion, we provide evidence for a functional correlation between a naturally occurring DN STAT5 and a biological response.     

A closer look at the frame-of-reference effect in personality scale scores and validity.

This article contributes to the understanding of why the use of a frame-of-reference leads to increased criterion-related validity of personality inventories. Two competing explanations are described and tested. A between-subjects (N = 337) and a within-subject (N = 105) study are conducted to test the hypothesized effects of use of a frame of reference on reliability and validity. Regarding the effects on reliability, use of a frame of reference reduces within-person inconsistency (instead of between-person variability) in responding to generic items. Use of a frame of reference further leads to higher validity as a result of the reduction of between-person variability and within-person inconsistency. Yet, reducing these inconsistencies is not enough. It is also important to use a frame of reference that is conceptually relevant to the criterion. Besides implications for contextualized personality inventories, these results provide an explanation for the moderate validities of generic personality inventories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alternative Reagents for Methotrexate as Immobilizing Anchor Moieties in the Optimization of MASPIT: Synthesis and Biological Evaluation

We report the evaluation of two alternative chemical dimerizer approaches aimed at increasing the sensitivity of MASPIT, a three‐hybrid system that enables small‐molecule target protein profiling in intact human cells. To circumvent the potential limitations related to the binding of methotrexate (MTX) to endogenous human dihydrofolate reductase (DHFR), we explored trimethoprim (TMP) as an alternative prokaryote‐specific DHFR ligand. MASPIT evaluation of TMP fusion compounds with tamoxifen, reversine, and simvastatin as model baits, resulted in dose–response curves shifted towards lower EC₅₀ values than those of their MTX congeners. Furthermore, a scalable azido‐TMP reagent was synthesized that displayed a similar improvement in sensitivity, possibly owing to increased membrane permeability relative to the MTX anchor. Applying the SNAP‐tag approach to introduce a covalent bond into the system, on the other hand, produced an inferior readout than in the MTX‐ or TMP‐tag based assay.     

Pd as a promoter to reduce Co cluster films at room temperature

The optical and resistivity properties of Pd/Co films are investigated and related to the interaction of palladium and the underlying cobalt (Co) clusters layer when exposed to hydrogen. Co is used because it is known to absorb hydrogen only on its surface. Co clusters with mean size of 1.8 nm in the gas phase were deposited on sapphire substrates at room temperature (RT), 300 °C, and 500 °C, respectively, and capped by a continuous Pd film. Light transmission and reflection in the visible range were measured during hydrogen exposure at different pressures in consecutive cycles. An unusual change in the transmittance and the resistance during the first hydrogenation cycle of a sample suggests that a reduction of the surface oxide on the Co clusters layer occurs at room temperature. The reduction of the native oxide on Co thin films or bulk does not happen without the Pd capping when exposed to hydrogen under similar conditions.