Use of a microchip device coupled with mass spectrometry for ligand screening of a multi-protein target

Nanoflow electrospray mass spectrometry has been applied previously to investigate noncovalent protein-protein and protein-ligand interactions. Here we evaluate a commercial microchip device for this application. We show that the microchip can be used to obtain mass spectra of the noncovalent tetramer transthyretin. The device showed a 10-fold increase in signal stability compared with a nanoflow capillary and a high level of nozzle-to-nozzle reproducibility. Binding of the natural ligand thyroxine was clearly observed, and a range of small molecules proposed as inhibitors of transthyretin amyloidosis were shown to be effective in stabilizing the tetramer. We propose that measuring the ability of small molecules to stabilize protein complexes using this automated microchip technology will enable high-throughput screening of multi-protein complexes by mass spectrometry.     

The impact of print exposure quality and inference construction on syllogistic reasoning.

This study extended the work of S. Siddiqui, R. F. West, and K. E. Stanovich (1998), who studied the link between general print exposure and syllogistic reasoning. It was hypothesized that exposure to certain text structures that contain well-delineated logical forms, such as popularized scientific texts, would be a better predictor of deductive reasoning skill than general print exposure, which is not sensitive to the quality of an individual's reading activity. Furthermore, it was predicted that the ability to generate explanatory bridging inferences while reading would also be predictive of syllogistic reasoning. Undergraduate students (N = 112) were tested for vocabulary, nonverbal cognitive ability, exposure to general print, exposure to popularized scientific literature, and the ability to comprehend texts distinguished by the number of inferences that must be generated to support comprehension. Hierarchical multiple regression analyses showed that a combined measure of exposure to general and scientific literature was a significant predictor of syllogistic reasoning ability. Additionally, the ability to comprehend high-inference-load texts was related to solving syllogisms that were inconsistent with world knowledge, indicating an overlap in deductive reasoning skill and text comprehension processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual web searches in Facebook using learning materials and discussion messages

The web is nowadays one of the main information sources, and information search is an important area in which many advances have been registered. One approach to improve web search results is to consider contextual information. Usually, information about context has been provided through user logs on previous searches or the monitoring of clicks on first results, but different approaches can be used in specific environments. In a web based learning environment, existing documents and exchanged messages could provide contextual information. So, the main goal of this work is to provide a contextual web search engine based on shared documents and messages posted in a social network used for collaborative learning. Contextual search is provided through query expansion using learning documents (material provided by the teacher) and discussion messages (posts, links and comments that result from the participants’ interactions). A prototype was implemented and used in a learning scenario to acquire the context in a learning community. The proposed approach makes the context acquisition faster and more dynamic as it considers an automatic approach over text processing of documents and discussions. In addition, the results of the query engine with and without the contextual information were compared and the proposed approach using contextual information showed improvements in the precision of the results.     

Turing’s man: a dialogue

We can never emulate their meekness, soft servants of durable material: they live without pretension in complicated relays and electrical circuits. Speed, docility are their strength. One asks: “What is 2 × 2?”—“Are you a machine?” They answer or refuse to answer, depending on what you demand. There are, however, other machines as well, more abstract automatons, bolder and more inaccessible, which eat their tape in mathematical formulae. They imitate in language. In infinite loops, farther and farther back in their retreat towards more subtle algorithms, more recursive functions. They are logical and describe themselves. As when a man with a hand-mirror pressed against his nose in front of a mirror sees in infinite rows the same image multiplied in a shrinking, darkening corridor of glass. It is a Gödel theorem as good as any. He sees infinity, but what he does not see is his face. (From Göran Printz-Påhlson´s poem “The Turing Machine” published in Säg minns du skeppet Refanut? Samlade dikter 1950–1983 (1984) Bonniers, Stockholm).     

Robust 3D face capture using example-based photometric stereo

We show that using example-based photometric stereo, it is possible to achieve realistic reconstructions of the human face. The method can handle non-Lambertian reflectance and attached shadows after a simple calibration step. We use spherical harmonics to model and de-noise the illumination functions from images of a reference object with known shape, and a fast grid technique to invert those functions and recover the surface normal for each point of the target object. The depth coordinate is obtained by weighted multi-scale integration of these normals, using an integration weight mask obtained automatically from the images themselves. We have applied these techniques to improve the PhotoFace system of Hansen et al. (2010).     

In-hospital smoking cessation programs: Who responds, who doesn't?

This study extends the results of a large randomized clinical trial of a multicomponent in-hospital smoking cessation intervention for general hospitalized smokers by examining subgroups of patients who responded to the intervention. The results, obtained using signal detection analysis, produced 6 subgroups of patients with varying degrees of intervention responsiveness. The subgroup most responsive was marked by 100% confidence to quit smoking at baseline. Among patients with less than 100% confidence, confidence interacted with age, depressed mood scores, addiction scores, and alcohol intake to discriminate 5 additional subgroups. Discussion focuses on how this information can be used in clinical decision making to treat subpopulations of smokers and directs attention to possible areas of underlying biopsychosocial processes that may interact to affect successful long-term cessation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimization of operational planning for wind/hydro hybrid water supply systems

Water supply systems (WSS) frequently present high-energy consumption values, which correspond to the major expenses of these systems. Energy costs are a function of its real consumption and of the variability of the daily energy tariff.This paper presents a model of optimization for the energy efficiency in a water supply system. The system is equipped with a pump station and presents excess of available energy in the gravity branch. First, a water turbine is introduced in the system in order to use this excess of hydraulic available energy. Then, an optimization method to define the pump operation planning along the 24 h of simulation, as well as the analysis of the economic benefits resulting from the profit of wind energy to supply the water pumping, while satisfying the system constraints and population demands, is implemented, in order to minimize the global operational costs.The model, developed in MATLAB, uses linear programming and provides the planning strategy to take in each time step, which will influence the following hours. The simulation period considered is one day, sub-divided in hourly time steps. The rules obtained as output of the optimization procedures are subsequently introduced in a hydraulic simulator (e.g. EPANET), in order to verify the system behaviour along the simulation period. The results are compared with the normal operating mode (i.e. without optimization algorithm) and show that energy cost's savings are achieved dependently of the initial reservoir levels or volume. The insertion of the water turbine also generates significant economical benefits for the water supply system.     

The synthesis and structural study of two benzothiazolyl azo dyes: X-ray crystallographic and computational study of azo–hydrazone tautomerism

The synthesis, FT-IR, ¹H and ¹³C NMR characterisation, as well as crystal and molecular structure determined by single-crystal X-ray diffraction data, of two azo dyes derived from 6-aminobenzothiazole: 6-[(4-N,N-dimethylaminophenyl)diazenyl]benzothiazole and 6-[(2-hydroxy-1-naphthyl)diazenyl]benzothiazole are reported. Both dyes are essentially planar with the exclusion of methyl groups in 6-[(4-N,N-dimethylaminophenyl)diazenyl]benzothiazole, which exibits 100% E-configuration in terms of orientation of the substituents about the central azo linkage. Single-crystal X-ray study of 6-[(2-hydroxy-1-naphthyl)diazenyl]benzothiazole was undertaken to established whether the hydrazone or azo tautomer was present in the solid state as well as any potential shift in tautomeric equilibrium imparted by temperature variation (296 and 100 K). Density functional theory calculations revealed that the hydrazone tautomer was more stable than the azo tautomer and that the tautomeric equilibrium was shifted towards the hydrazone form at lower temperature.     

Microstructure formation in chalcogenide thin films assisted by thermal dewetting

The spontaneous formation of self-assembled and/or self-organized patterns is a fundamental and technologically significant topic. This process is achieved via a phenomenon called dewetting, should it be thermally induced, or caused by laser exposure. Although dewetting seems to be a well-known phenomenon for metallic and polymeric thin films, no proper investigation regarding glassy thin films seems to have been done. Thus, in the present study we try to elaborate on the process of thermal dewetting applied to glassy thin films of the system Ag_x(As₂₀S₈₀)_100?x.     

Polyoxometalate catalyzed ozonation of chemical pulps in organic solvent media

Polyoxometalate (POM) catalyzed ozonation of chemical pulps in organic solvent media was found to be particularly effective and selective environmentally benign bleaching approach providing a way for substantial increase in pulp brightness, viscosity and degree of delignification in comparison with other ozone-based bleaching techniques. A series of tested low-boiling polar aprotic and protic organic solvents showed a well-defined capacity for ozonation improvement in the presence of Keggin-type heteropolyanion [PMo₇V₅O₄₀]⁸⁻ (HPA-5). Even moderate solvent proportion of 6% (w/w) in the reaction solution caused additional gain in brightness up to 3.4% ISO with simultaneous increase in pulp viscosity up to 8.8% and lignin removal up to 18.9% after HPA-5 catalyzed ozonation (0.8% O₃; 0.5 mM HPA), as compared with the control solvent-free process. An aqueous acetone solution was found to be the preferred reaction medium in terms of pulp brightening and delignification. Under optimized conditions, the POM-catalyzed ozonation of eucalypt kraft pulp in acetone/water solution showed remarkable brightness improvement by 15.1% ISO with additional lignin removal by 39.4% and increase in intrinsic viscosity by 3% in comparison with pulp bleached in water media.