Performing accurate joint kinematics from 3-D in vivo image sequences through consensus-driven simultaneous registration.

This paper addresses the problem of the robust registration of multiple observations of the same object. Such a problem typically arises whenever it becomes necessary to recover the trajectory of an evolving object observed through standard 3-D medical imaging techniques. The instances of the tracked object are assumed to be variously truncated, locally subject to morphological evolutions throughout the sequence, and imprinted with significant segmentation errors as well as significant noise perturbations. The algorithm operates through the robust and simultaneous registration of all surface instances of a given object through median consensus. This operation consists of two interwoven processes set up to work in close collaboration. The first one progressively generates a median and implicit shape computed with respect to current estimations of the registration transformations, while the other refines these transformations with respect to the current estimation of their median shape. When compared with standard robust techniques, tests reveal significant improvements, both in robustness and precision. The algorithm is based on widely-used techniques, and proves highly effective while offering great flexibility of utilization.     

Photocatalytic Inactivation of Legionella Pneumophila and an Aerobic Bacteria Consortium in Water over TiO2/SiO2 Fibres in a Continuous Reactor

A continuous photoreactor, working in a total recycle mode and irradiated by a low-pressure Hg lamp, has been used to study the bactericidal effect of a photocatalyst, formed by TiO₂ embedded in SiO₂ fibres, on Legionella pneumophila and a consortium of common gram-negative aerobic bacteria: (Escherichia coli, Klebsiella sp., Pseudomona sp. and Proteus sp.) in water. The kinetic modeling of the inactivation process, carried out with the measured values of viable bacteria concentration at the outlet of photoreactor, evidenced that for each pass inside the photoreactor the ratio between the outlet and inlet cell concentrations was of order of 0.01 for the inactivation of L. pneumophila. For the other aerobic bacteria, which are usually taken as reference in photocatalytic bacteria inactivation studies, this ratio was of order of 0.3 for the first hour of illumination, while upon prolonged irradiation (up to 9 h) this ratio increased to 0.7. Several factors inducing this latter decrease of efficiency are possible, as e.g. competition for photocatalytic attack between microorganisms and organic compounds released by damaged bacteria or photoinduced alteration of a small fraction of still viable bacteria making them less interactive with the photocatalyst. The inactivation mechanism normally proposed for common bacteria involves an initial attack of the photogenerated radicals to the outer membrane; the consequent membrane dispersion allows the radicals to damage the cytoplasmic membrane. The higher lethality of the photocatalytic method observed towards Legionella: (in comparison to the other aerobic bacteria) is explained considering that the radicals attack the Legionella secretion system, which is adapted for high virulence and would become activated for and through adhesion to the TiO₂ surface. This attack would then be able to inactivate L. pneumophila without dispersing the outer membrane. Apart from this, the water flow through the catalyst fibres can facilitate the bacteria transport towards the anatase surface, and additionally the generated shear stress may help adhesion, at least for some bacteria as E. coli, contributing further to improve the photokilling efficiency; both factors may contribute to the efficiency of this photoreactor configuration.     

Unsteady Bed Shear Stresses Induced by Navigation: Laboratory Observations

Time-dependent bed shear stresses induced by the passage of a barge tow have been measured with hot film shear stress sensors in a 1:25 scale model. Conditions typical of those observed for Upper Mississippi River navigation traffic were simulated in the experimental facility. Two sets of experiments were carried out: the first set consisted of simultaneous shear stress measurements at different locations for a variety of flow depths and boat operating conditions, providing space-time distributions of ensemble averaged wall shear stresses. The second set included a large number of realizations gathered for one particular flow condition at a single position, allowing analysis of the time evolution of the turbulence characteristics (i.e., standard deviation) of the bed shear stresses. The results of the first set of experiments show that for all the experimental conditions the basic patterns of the shear stress are similar, with two regions of high shear stress associated with the passage of the bow and the stern of the barge tow, respectively. Analysis of the second set of experiments showed that, as a result of the passage of the barge tow, the bed-shear stress standard deviation departs from the values commonly observed under steady, uniform, open-channel flow conditions. This behavior has important implications for sediment transport.     

Comparison of matrix solid-phase dispersion and liquid-liquid extraction for the chromatographic determination of fenthion and its metabolites in olives and olive oils

Matrix solid-phase dispersion (MSPD) methodology has been developed to extract fenthion and its metabolites from olives and olive oils, and the technique compared with conventional liquid-liquid extraction (LLE). The method was applied to olives and olive oil samples obtained from olive groves treated with fenthion. Pesticide residues were analysed by gas chromatography (GC) using a nitrogen-phosphorus detector. Both extraction methods gave a linear response over the concentration range assayed (0.03-1 mg kg^-1 for MSPD and 0.1-1 mg kg^-1 for LLE). Recoveries and RSD (n = 6) values in olives were 85-112% and 2-6% for MSPD, and 68-108% and 4-16% for LLE, respectively. In the case of olive oil, recoveries and RSD (n = 6) values were 67-98% and 5-11% for MSPD, and 63-115% and 6-14% for LLE, respectively. When compared to LLE, the newly developed MSPD method was twice as sensitive and required 10 times less sample weight.     

DETERMINATION OF β-GLUCAN IN WORT AND BEER BY ITS BINDING WITH CALCOFLUOR,USING A FLUORIMETRIC FLOW-INJECTION-ANALYSIS (FIA) METHOD

The FIA-fluorimetric methods for the determination of β-glucan in worts and beers have been investigated, modified and improved. Fluorescence is excited by using a mercury lamp and a 338 nm band-pass excitation filter, and detected using a 425 nm long-pass emission filter. It has been found that an increase of the ionic strength of the eluent, up to a maxium of 1% Sodium Chloride, increases the range of β-glucan molecular weights effectively bound by Calcofluor. The influence of the low molecular weight components of wort and beer: dextrins, aminoacids, etc, has been studied and found that their effect is negligible. The interference of wort and beer colour on the measurement of β-glucan has been quantified and several approaches are given to overcome it. Thirty-six European beers have been analyzed for β-glucan content. The possible detection of the addition of exogenous β-glucanases to wort and beer is discussed.     

Transition to adulthood as a parent-youth project: Governance transfer, career promotion, and relational processes.

This study determined how youth (ages 17-21) and their parents jointly constructed and acted on goals and strategies pertinent to the transition to adulthood. Twenty parent-youth dyads were followed over an 8-month period using the qualitative action-project method. Data included their joint conversations, video recall of internal processes, self-monitoring logs, and researcher telephone monitoring. Detailed and repeated analysis of elements, functional steps, and goals resulted in the identification of an explicit joint project for each dyad that the participants saw as pertinent to the transition to adulthood. These projects referred broadly to the youth development of identity and social inclusion in the adult world and included the specific projects of career promotion, governance transfer, and parent-youth relational processes. The findings illustrate the complexity of the transition-to-adulthood process as well as its joint construction by parent and youth. Implications for practice include identifying and following the joint parent-youth transition project. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Timing error estimation for baseband multicarrier modulation

In this paper, the topic of timing error estimation for baseband discrete multitone modulation is addressed in the context of high‐speed digital subscriber line applications. To the authors' best knowledge, this problem is sparsely and not in depth treated in the literature. In this study the modified Cramer–Rao lower bound is derived, two conventional estimators are considered and a new one is proposed. Behavior of these estimators is evaluated in terms of bias, variance and computational complexity in a wide variety of scenarios, concluding that the proposed estimator appears to be superior in all instances. Copyright © 2008 John Wiley & Sons, Ltd.     

Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

The salting-out effect produced by the addition of potassium phosphate, K₃PO₄ to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl) is investigated. The effects are analyzed using both the corresponding temperature–composition pseudo-binary and composition ternary phase diagrams. Different regions of liquid-liquid and solid-liquid phase demixing are mapped. The phase behavior is interpreted taking into account the complex and competing nature of the interactions between the ionic liquid, the inorganic salt and water. In the case of solutions containing 1-octyl- or 1-decyl-3-methylimidazolium chloride, the smaller magnitude of the salting-out effects is explained in terms of the possibility of self-aggregation of the ionic liquid.