An investigation of the predictive validity and economic utility of the assessment center for the high-management level.

Obtained final ratings on 25 assessment dimensions for 382 candidates for high-level management positions in an Israeli corporation. The ratings were determined by an assessment center process, 2 clinically derived assessment scores, and a mechanically derived assessment score. For 49 of the assessees, scores were also available on a battery of paper-and-pencil cognitive tests. For all Ss, data were obtained on 2 criterion measures over a period of 4 yrs. Both the general intelligence rating formulated in the assessment center and the scores on the cognitive tests were found to be predictively invalid, while the personality measure proved valid. Despite the modest coefficients of predictive validity found for the other assessment center predictors, the economic utility analysis performed with an amended formula demonstrated a cost-effectiveness for the assessment center program. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Novel Synthesis of Ordered MCM-41 Titanosilicates with Very High Titanium Content via Ultrasound Radiation

A novel synthetic strategy has been developed for the fabrication of mesostructured titanosilicate with very high titanium content. By the combination of ultrasound radiation and a separate hydrolysis procedure, highly ordered MCM-41 titanosilicates can be synthesized within 3 h from gels with Ti/Si ratios up to 1. The physicochemical properties of the materials were characterized by means of XRD, TEM, FT-IR, UV-Vis DRS, ²⁹Si MAS NMR, and liquid nitrogen adsorption-desorption measurements. The results suggested that during crystallization, sonication re-dispersed and accelerated the condensation of inorganic species, and resulted in more condensed pore walls compared to those synthesized with the conventional methods. The presence of silica and ultrasound radiation remarkably suppressed the aggregation of titanium species, thus, at the medium titanium level, a relatively homogeneous dispersion of titanium within the MCM-41 framework was attained.     

Effects of command style and group cohesiveness on the performance effectiveness of self-selected tank crews.

94 3-men crews of Israeli male soldiers were studied throughout their performance on routine military activities. Level of cohesiveness was determined through a self-selection sociometric procedure. Command style of tank commanders was assessed with questionnaires. Performance was appraised by unit commanders. Results show only interaction effects of cohesiveness and command style on performance effectiveness. Specifically, performance effectiveness was high in the following combinations: low cohesiveness with command style that emphasizes people orientation and high cohesiveness with emphasis on both task and people orientation. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Representation Analysis and Synthesis of Lip Images Using Dimensionality Reduction

Understanding facial expressions in image sequences is an easy task for humans. Some of us are capable of lipreading by interpreting the motion of the mouth. Automatic lipreading by a computer is a challenging task, with so far limited success. The inverse problem of synthesizing real looking lip movements is also highly non-trivial. Today, the technology to automatically generate an image series that imitates natural postures is far from perfect. We introduce a new framework for facial image representation, analysis and synthesis, in which we focus just on the lower half of the face, specifically the mouth. It includes interpretation and classification of facial expressions and visual speech recognition, as well as a synthesis procedure of facial expressions that yields natural looking mouth movements. Our image analysis and synthesis processes are based on a parametrization of the mouth configuration set of images. These images are represented as points on a two-dimensional flat manifold that enables us to efficiently define the pronunciation of each word and thereby analyze or synthesize the motion of the lips. We present some examples of automatic lips motion synthesis and lipreading, and propose a generalization of our solution to the problem of lipreading different subjects.     

High yield one-step synthesis of carbon spheres produced by dissociating individual hydrocarbons at their autogenic pressure at low temperatures

Hydrocarbons containing 5–14 carbon atoms (pentane, cyclohexane, camphorquinone, xylene, mesitylene, camphene, decahydronaphthalene, diphenylmethane, and anthracene) are individually dissociated under their autogenic pressure developed at 700 °C to produce pure carbon moieties from the respective hydrocarbon precursor. From all of the hydrocarbons, more than 99% pure carbon is obtained in spherical, filament- or egg-like microstructures. One of the key peculiarities in the thermal dissociation of various hydrocarbons, followed by solidification under autogenic pressure, is the formation of products in micrometer dimensions. It is in contrast to previous work with organometallic precursors, which yield nanometric products via a similar method. These results are compared with those obtained for the thermal dissociation of the same hydrocarbons under flow conditions. Specific systematic morphological, structural, and compositional analysis is presented for the products obtained from the thermal dissociation of diphenylmethane. A possible formation mechanism for the obtained products is provided.     

Sonochemical coating of silver nanoparticles on textile fabrics (nylon, polyester and cotton) and their antibacterial activity

Silver nanoparticles were synthesized and deposited on different types of fabrics using ultrasound irradiation. The structure of silver-fabric composites was studied by physico-chemical methods. The mechanism of the strong adhesion of silver nanoparticles to the fibers is discussed. The excellent antibacterial activity of the Ag-fabric composite against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) cultures was demonstrated.     

Organic-inorganic hybrid materials based on polyaniline/TiO(2) nanocomposites for ascorbic acid fuel cell systems

Polyaniline was grafted onto a mixture of rutile and anatase TiO(2) nanoparticles by in situ chemical oxidative polymerization. These nanocomposites were characterized by carbon, hydrogen and nitrogen (CHN) analysis, x-ray diffraction (XRD), Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. FTIR and UV-vis confirm the formation of polyaniline on TiO(2) nanoparticles. The TEM shows that the composites consist of PANI and TiO(2) nanoparticles. Compared to the neat polyaniline, PANI/TiO(2) composites show a higher capacitance and also a higher activity per mass of polyaniline. Since the PANI/TiO(2) composites are stable during the electrooxidation of ascorbic acid, they can be used as an alternative catalyst for direct ascorbic acid fuel cells.     

A template-free, sonochemical route to porous ZnO nano-disks

A template-free, sonochemical aqueous route was used to synthesize hexagonal-shaped ZnO nanocrystals with a combined micro- and mesoporous structure. The products are much more porous when the sonohydrolysis is carried out under argon than their sonication under air. This has been attributed to the higher average specific heat ratio γ (=C_p/C_v) of argon gas, leading to higher bubble collapse temperatures. Small-angle XRD (SAXRD) studies show that the microporosity is lost at 250 °C, while the mesoporous structure persists till a very high temperature (550 °C). The BET surface area of the products synthesized under argon and air are 35 and 13 m²/g, respectively. The pore size is distributed from 1 nm (micropore) to 3.1–3.4 nm (mesopore), while the ZnO nanoparticles are 6.3 ± 1.2 nm. The possible mechanisms of the self-assembled pore formation are attributed to the organic porous framework of basic zinc acetate. The excitonic absorption of the ZnO occurs at 349 nm. The photoluminescence (PL) spectra of the ZnO nano-disks show the red-shifted band edge exciton transitions and the presence of deep levels due to oxygen vacancies or surface-deep traps, because of the porous structure.     

Modified PVA-Fe3O4 nanoparticles as protein carriers into sperm cells

Magnetite nanoparticles conjugated to protein are developed in order to potentially serve as protein carriers into bovine sperm cells. The conjugate comprises iron oxide nanoparticles that are covalently bound to an anti-protein kinase C (PKC)alpha antibody. This conjugate can serve for cellular PKC localization and the inhibition of its function. The surface of the nanoparticle is first modified with (3-aminopropyl) thrimethoxysilane to form a self-assembled monolayer, and subsequently conjugated with the antibody through amidation between the carboxylic acid end groups on the antibody and the amine groups on the surface of the nanoparticles. The anti-PKCalpha localization is proven by fluorescent microscopy and iron staining. The activity of the anti-PKCalpha conjugated with the nanoparticle is tested by recognizing PKCalpha using the Western blot method.     

Two are Better than One: Combining ZnO and MgF2 Nanoparticles Reduces Streptococcus pneumoniae and Staphylococcus aureus Biofilm Formation on Cochlear Implants

Streptococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S.aureus) are considered the most common colonizers of cochlear implants (CI), which have prompted the search for new ways to inhibit their growth and biofilm development. In the current study, CI‐based platforms are prepared and sonochemically coated with ZnO or MgF₂ nanoparticles (NPs), two agents previously shown to possess antibacterial properties. Additionally, a method is developed for coating both ZnO and MgF₂ on the same platform to achieve synergistic activity against both pathogens. Each surface is characterized, and the optimal conditions for the NP homogenous distribution on the surface are determined. The ZnO‐MgF₂ surface significantly reduces the S. pneumoniae and S. aureus biofilm compared with the surfaces coated with either ZnO or MgF₂, even though it contains smaller amounts of each NP type. Importantly, leaching assays show that the NPs remain anchored to the surface for at least 7 d. Finally, biocompatibility studies demonstrate that coating with low concentrations of ZnO‐MgF₂ results in no toxicity toward primary human fibroblasts from the auditory canal. Taken together, these findings underscore the potential of using NP combinations such as the one presented here to efficiently inhibit bacterial colonization and growth on medical devices such as CIs.