Work Group Diversity and Group Performance: An Integrative Model and Research Agenda.

Research on the relationship between work group diversity and performance has yielded inconsistent results. To address this problem, the authors propose the categorization-elaboration model (CEM), which reconceptualizes and integrates information/decision making and social categorization perspectives on work-group diversity and performance. The CEM incorporates mediator and moderator variables that typically have been ignored in diversity research and incorporates the view that information/decision making and social categorization processes interact such that intergroup biases flowing from social categorization disrupt the elaboration (in-depth processing) of task-relevant information and perspectives. In addition, the authors propose that attempts to link the positive and negative effects of diversity to specific types of diversity should be abandoned in favor of the assumption that all dimensions of diversity may have positive as well as negative effects. The ways in which these propositions may set the agenda for future research in diversity are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of steel on the mechanical stress development during hydrogen-loading of ultrathin Nb-films

Thin films attached on rigid substrates can develop ultra-high compressive stresses upon hydrogen-loading. These high stresses can be released by dislocation-formation or delamination. For niobium thin films dislocation-formation was observed for films thicker than 6 nm upon hydrogen-loading up to 1 H/Nb. By alloying niobium with steel the critical film thickness for dislocation formation can be increased to at least 37 nm. TEM and EELS studies on the film's microstructure and elemental distribution show Fe-enriched regions being present at grain boundaries. This refines the hydrogen-absorbing Nb grain sizes thereby hardening the material.     

Glioma vessel abnormality quantification using time-of-flight MR angiography

Objectives

To differentiate between abnormal tumor vessels and regular brain vasculature using new quantitative measures in time-of-flight (TOF) MR angiography (MRA) data.

Materials and methods

In this work time-of-flight (TOF) MR angiography data are acquired in 11 glioma patients to quantify vessel abnormality. Brain vessels are first segmented with a new algorithm, efficient monte-carlo image-analysis for the location of vascular entity (EMILOVE), and are then characterized in three brain regions: tumor, normal-appearing contralateral brain, and the total brain volume without the tumor. For characterization local vessel orientation angles and the dot product between local orientation vectors are calculated and averaged in the 3 regions. Additionally, correlation with histological and genetic markers is performed.

Results

Both the local vessel orientation angles and the dot product show a statistically significant difference (p < 0.005) between tumor vessels and normal brain vasculature. Furthermore, the connection to both histology and the gene expression of the tumor can be found—here, the measures were compared to the proliferation marker Ki-67 [MIB] and genome-wide expression analysis. The results in a subgroup indicate that the dot product measure may be correlated with activated genetic pathways.

Conclusion

It is possible to define a measure of vessel abnormality based on local vessel orientation angles which can differentiate between normal brain vasculature and glioblastoma vessels.

     

Naphthacenodithiophene Based Polymers—New Members of the Acenodithiophene Family Exhibiting High Mobility and Power Conversion Efficiency

Wide‐bandgap conjugated polymers with a linear naphthacenodithiophene (NDT) donor unit are herein reported along with their performance in both transistor and solar cell devices. The monomer is synthesized starting from 2,6‐dihydroxynaphthalene with a double Fries rearrangement as the key step. By copolymerization with 2,1,3‐benzothiadiazole (BT) via a palladium‐catalyzed Suzuki coupling reaction, NDT‐BT co‐polymers with high molecular weights and narrow polydispersities are afforded. These novel wide‐bandgap polymers are evaluated as the semiconducting polymer in both organic field effect transistor and organic photovoltaic applications. The synthesized polymers reveal an optical bandgap in the range of 1.8 eV with an electron affinity of 3.6 eV which provides sufficient energy offset for electron transfer to PC₇₀BM acceptors. In organic field effect transistors, the synthesized polymers demonstrate high hole mobilities of around 0.4 cm² V^–1 s^–1. By using a blend of NDT‐BT with PC₇₀BM as absorber layer in organic bulk heterojunction solar cells, power conversion efficiencies of 7.5% are obtained. This value is among the highest obtained for polymers with a wider bandgap (larger than 1.7 eV), making this polymer also interesting for application in tandem or multijunction solar cells.     

Tocotrienol levels in sieving fraction extracts of brewer’s spent grain

Dried brewer’s spent grain (DBSG) is rich in tocotrienols (T3) and tocopherols (T) and can be used to produce a valuable oil with the serum cholesterol–lowering functions of lipid-soluble T3. The economic feasibility of extracting oil from DBSG (fat: 3.9–10.6% dry weight, dw) increases with increasing fat content of the feedstock. The objective of this research was to determine whether DBSG can be separated into fractions enriched in fat and T3 by milling and sieving and to characterize the fractions from sieves of different mesh sizes: 500, 800, 850, and 1,000 μm. Six different charges of DBSG were milled and sieved with different techniques ranging in scale from laboratory to industrial. The oil yield of DBSG sieving fractions >500 μm was consistently low (6.6–12.67% dw after Soxhlet extraction with 96% ethanol), as were the levels of T (77.4–185.6 mg/kg of extracted oil), T3 (181.9–538.8 mg/kg of extracted oil), and protein (14.38–25.73% dw). In contrast, oil yields of DBSG sieving fractions <500 μm were higher (12.98–18.09% dw after Soxhlet extraction with 96% ethanol), as were the concentrations of T (188.6–318.0 mg/kg of extracted oil), T3 (516.8–850.2 mg/kg of extracted oil), and protein (26.05–33.30% dw). Furthermore, oil yields were lower (8.24–12.39% dw) after Soxhlet extraction with n-hexane. Milled DBSG sieving fractions <500 μm thus appear to be a suitable feedstock for economical extraction of T3-rich oil and may be useful in developing markets for value-added brewing by-products.     

天安百货

天安百货位于新的总体规划中商业区一端的主要通道上，它标志着新的发展区域和功能，是满足不同顾客的不同需求的吸引点。建筑的空间设计是为了延长顾客在建筑中的停留时间：其本质是内部空间与外表皮之间的转换。通过在建筑表皮上四个不同部分的堆叠，表达了一种流动性。     

Stability of Low-Friction Surface Sliding of Nanocrystals with Rectangular Symmetry and Application to W on NaF(001)

We investigate the stability of low-friction sliding of nanocrystal with rectangular atomic arrangement on rectangular lattices, for which analytical results can be obtained. We find that several incommensurate periodic orbits exist and are stable against thermal fluctuations and other perturbations. As incommensurate orientations lead to low corrugation, and therefore low friction, such incommensurate periodic orbits are interesting for the study of nanotribology. The analytical results compare very well with simulations of W nanocrystals on NaF(001). The geometry and high typical corrugation of substrates with square lattices increase the robustness when compared to typical hexagonal lattices, such as graphite.     

Assessment of numerical optimization algorithms for the development of molecular models

In the pursuit to study the parameterization problem of molecular models with a broad perspective, this paper is focused on an isolated aspect: It is investigated, by which algorithms parameters can be best optimized simultaneously to different types of target data (experimental or theoretical) over a range of temperatures with the lowest number of iteration steps. As an example, nitrogen is regarded, where the intermolecular interactions are well described by the quadrupolar two-center Lennard-Jones model that has four state-independent parameters. The target data comprise experimental values for saturated liquid density, enthalpy of vaporization, and vapor pressure. For the purpose of testing algorithms, molecular simulations are entirely replaced by fit functions of vapor-liquid equilibrium (VLE) properties from the literature to assess efficiently the diverse numerical optimization algorithms investigated, being state-of-the-art gradient-based methods with very good convergency qualities. Additionally, artificial noise was superimposed onto the VLE fit results to evaluate the numerical optimization algorithms so that the calculation of molecular simulation data was mimicked. Large differences in the behavior of the individual optimization algorithms are found and some are identified to be capable to handle noisy function values.     

Great globe thistle fruit (Echinops sphaerocephalus L.), a potential new oil crop

New plant oil crops are desirable as renewable resources for energy, for food purposes, and as building blocks in chemical synthesis. Fruit oil of Echinops sphaerocephalus was characterized by a high content of linoleic acid (over 70% of total fatty acids) and by a high tocopherol content (530–970 mg/kg oil). The majority was α‐tocopherol. Echinops sphaerocephalus plants may be cultivated in agricultural dimensions, and fruits may be obtained by a combine harvester. Echinops quinoline alkaloids present a useful by‐product of the oil production.