Carrier trapping and delocalization in PbI2-containing CdI2 crystals

Two pairs of electron and hole traps have been identified in PbI₂-containing CdI₂ crystals in the range 80–305 K using a combination of thermally stimulated and photoinduced depolarization of a photoelectret state. The electron traps are identified as Pb⁺ centers in nanocrystalline 2H- and 4H-PbI₂ inclusions in the CdI₂ lattice. One of the hole centers is assumed to be a Pb²⁺ vacancy. All of the traps in the binary crystalline system are related to the presence of PbI₂ impurities as a consequence of the formation of heterojunctions between the CdI₂ matrix and nanocrystalline PbI₂ inclusions. We have calculated the energy distribution for filled traps.     

Antecedents of construction project coalitions: a study of the Spanish construction industry

Research into the formation of alliances, relevant in the field of strategic management and especially, in the construction industry, is often explained in terms of interdependency and complementarities (exogenous factors). In contrast, the influence of a firm’s social relations networks (endogenous factors) has hardly been studied at all. Thus, a model is needed that includes both exogenous and endogenous factors as antecedents to the formation of strategic alliances in the construction industry. Cooperation in the construction sector is especially frequent, above all in public works programmes, as their scale requires coalitions of different‐sized firms. Accordingly, to explore how both exogenous and endogenous factors influence the formation of alliances, a social network analytical method—Multiple Regression Quadratic Assignment Procedure (MRQAP)—was applied to cooperative project coalitions in the Spanish public works construction sector from 2001–2007. Empirical findings confirm that construction companies form coalitions, principally on the basis of past alliances. Membership of business associations and groups is also a key factor, though the influence of geographic proximity is the most debatable result. In the construction industry, the formation of alliances is conditioned, among other factors, by previous social and economic relations that can generate the necessary information and trust for the selection of whichever partner is considered the most suitable for the development of the joint project.     

Culture and ideology in Ian Suttie's theory of mind.

The author discusses the comprehensive outlook that shaped Ian Suttie's psychology. Suttie is seen as a background influence behind the British school of psychoanalysis, and his ideas pervade that school and therefore late-modern notions of the mind. The author describes the formation of Suttie's independent theory, and argues that his project was expressly ideological, as he tried to counter what he saw as the reactionary and disruptive influence of Freud's classical theory. Suttie offered an optimistic perception of the mind, which could serve as the basis for a progressive social policy. This perception was rooted in the outlook of early 20th-century reforming liberalism, whose preferences and prejudices it shares. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Histological changes induced by CO2 laser microprobe specially designed for root canal sterilization: in vivo study

Sixty-six class-II CAD/CAM-manufactured ceramic inlays (Cerec) were placed in 27 patients. Each patient received at least one inlay luted with a dual-cured resin composite and one inlay luted with a chemically cured resin composite. The inlays were examined 5 years after luting using the California Dental Association (CDA) criteria. Eighty-nine percent of the 66 inlays were rated 'satisfactory'. During the follow-up period replacement was required for 3 inlays because of inlay fractures (4.5%) and 1 inlay because of fracture of the tooth substance (1.5%). All those inlays were luted with the dual-cured resin composite luting agent. Of the remaining 62 inlays the CDA rating 'excellent' was given to 84% for color, 97% for surface, and 81% for anatomic form. 'Excellent' margin integrity was seen in 52% of the dual-cured resin composite luted inlays and in 61% of the chemically cured resin composite luted inlays. No statistically significant (P> 0.05) difference was observed between the two luting agents.     

Clay Mineralogy of Mediterranean Brown Forest Soil

The mineralogical composition of the clay fraction and the non-carbonate residue in the parent rocks of 9 Mediterranean brown forest soils was determined, using X-ray diffraction DTA, Integral Thermal Analysis, electron microscopy and precise chemical analytical technique. The percentage ratio in the clay fraction of the soil and in the non-carbonate residue of the corresponding parent material was analyzed statistically and found low correlation. This is to be expected because of the great variability in the parent rock and the difficulty of collecting representative samples of the rocks. The genesis of these soils was compared to that of terra-rossa and rendzina soils (for which there is a very high correlation between rock and clay). The dominant clay mineral present was montmorillonite. In some soils fairly high amounts of kaolin were found. The basis for considering this soil type as a bridge between terra-rossa and rendzina is discussed.     

Odor-driven attractor dynamics in the antennal lobe allow for simple and rapid olfactory pattern classification

The antennal lobe plays a central role for odor processing in insects, as demonstrated by electrophysiological and imaging experiments. Here we analyze the detailed temporal evolution of glomerular activity patterns in the antennal lobe of honeybees. We represent these spatiotemporal patterns as trajectories in a multidimensional space, where each dimension accounts for the activity of one glomerulus. Our data show that the trajectories reach odor-specific steady states (attractors) that correspond to stable activity patterns at about 1 second after stimulus onset. As revealed by a detailed mathematical investigation, the trajectories are characterized by different phases: response onset, steady-state plateau, response offset, and periods of spontaneous activity. An analysis based on support-vector machines quantifies the odor specificity of the attractors and the optimal time needed for odor discrimination. The results support the hypothesis of a spatial olfactory code in the antennal lobe and suggest a perceptron-like readout mechanism that is biologically implemented in a downstream network, such as the mushroom body.     

Estimates of the dose due to 222Rn concentrations in water

About 300 samples of groundwater were collected in the region of Extremadura (Spain) in order to analyse their radon activity concentrations. Correlations with the geological characteristics of the aquifer soil were studied. Internal doses by inhalation due to radon exhalation from the water sample and doses by ingestion were estimated. A model was used to calculate the lung dose due to inhalation of radon exhaled from the water. The estimated lung dose range found for the samples was from 2.1 x 10(-3) to 13 mSv a(-1) (the average contribution to the dose due to radon inhalation in Spain being approximately 1.2 mSv a(-1)). The estimated dose by ingestion ranged from 4.1 x 10(-4) to 3.3 mSv a(-1).