Ribosomal DNA spacer probes for yeast identification: studies in the genus Metschnikowia

To test whether DNA probes derived from ribosomal DNA spacer sequences are suitable for rapid and species-specific yeast identification, a pilot study was undertaken. A 7.7 kb entire ribosomal DNA unit of the type strain of Metschnikowia reukaufii was isolated, cloned and mapped. A 0.65 kb BamHI-HpaI fragment containing non-transcribed spacer sequences was amplified and selected for testing as a 32P hybridization probe with total DNA from the type strains of M. reukaufii, M. pulcherrima, M. lunata, M. bicuspidata, M. australis, M. zobellii, M. krissii, five other strains identified as M. reukaufii and strains of Schizosaccharomyces pombe, Hansenula canadensis, Saccharomyces cerevisiae and Yarrowia lipolytica. The probe hybridized exclusively with DNA from the type strain and four other strains of M. reukaufii. DNA from one strain labelled M. reukaufii did not hybridize with the probe. Subsequent % G + C comparison and DNA-DNA reassociation with the type strain revealed that the non-hybridizing strain does not belong to the species M. reukaufii.     

Cervical epidural anesthesia for carotid mycotic aneurysms

Extracranial mycotic aneurysms of the carotid are unusual. We present such an aneurysm of the right primary carotid caused by enteritis due to Salmonella in a 75-year-old patient at high risk for surgery (myocardial ischemia evolving over 3 months) and with coexisting stenosis of 75% of the left internal carotid. Endarterectomy of the left internal carotid, with shunting, was performed, after which the right primary carotid was tied during the same operation. Epidural anesthesia to C6-C7 was provided through a catheter supplemented with an intravenous propofol infusion. Neurological and hemodynamic variables monitored during surgery were stable. No neurological deficits or myocardial ischemic changes were recorded. Three months after discharge the patient was asymptomatic.     

Bottom‐Up Fabrication of Semiconductive Metal–Organic Framework Ultrathin Films

Though generally considered insulating, recent progress on the discovery of conductive porous metal–organic frameworks (MOFs) offers new opportunities for their integration as electroactive components in electronic devices. Compared to classical semiconductors, these metal–organic hybrids combine the crystallinity of inorganic materials with easier chemical functionalization and processability. Still, future development depends on the ability to produce high‐quality films with fine control over their orientation, crystallinity, homogeneity, and thickness. Here self‐assembled monolayer substrate modification and bottom‐up techniques are used to produce preferentially oriented, ultrathin, conductive films of Cu‐CAT‐1. The approach permits to fabricate and study the electrical response of MOF‐based devices incorporating the thinnest MOF film reported thus far (10 nm thick).     

Organic Dye Graphene Hybrid Structures with Spectral Color Selectivity

This study characterizes a hybrid structure formed between graphene and organic dye molecules for use in photodetectors with spectral color selectivity. Rhodamine‐based organic dye molecules with red, green, or blue light absorption profiles are deposited onto a graphene surface by dip‐coating. UV–vis absorption spectroscopy, charge transport measurements, and density functional theory based calculations reveal that the photoresponses of the dye graphene hybrid films are governed by the light absorption of the dye molecules and also by the photo‐excited‐charge‐transfer‐induced photocurrent gain. The hybrid films respond only to photons with an energy exceeding the band gap of the immobilized dye. Dye‐Graphene charge transfer is affected by the distance and direction of the dipole moment between the two layers. The resulting hybrid films exhibit spectral color selectivities with responsivities of ≈10³ A W^?1 and specific detectivities of ≈10¹⁰ Jones. This study demonstrates the successful operation of photodetectors with a full‐color optical bandwidth using hybrid graphene structures coated with a mixture of dyes. The strategy of building a simple hybrid photodetector can further offer many opportunities to be also tuned for other optical functionalities using a variety of commercially available dye molecules.     

A Linear Algorithm for the Random Sampling from?Regular Languages

We present the first linear algorithm for the random sampling from regular languages. More precisely, for generating a uniformly random word of length n in a given regular language, our algorithm has worst-case space bit-complexity O(n) and mean time bit-complexity?O(n). The previously best algorithm, due to Denise and Zimmermann (Theor. Comp. Sci. 218(2):233–248, 1999), has worst-case space bit-complexity O(n ²) and mean time bit-complexity O(nlog?(n)). The Denise et al. algorithm was obtained by performing a floating-point optimization on the general recursive method formalized by Nijenhuis and Wilf (and further developed by Flajolet, Zimmermann and Van Cutsem). Our algorithm combines the floating-point optimization with a new divide-and-conquer scheme.     

A framework for the application of metaheuristics to?tasks-to-processors assignation problems

The optimization of the execution time of a parallel algorithm can be achieved through the use of an analytical cost model function representing the running time. Typically the cost function includes a set of parameters that model the behavior of the system and the algorithm. In order to reach an optimal execution, some of these parameters must be fitted according to the input problem and to the target architecture. An optimization problem can be stated where the modeled execution time for the algorithm is used to estimate the parameters. Due to the large number of variable parameters in the model, analytical minimization techniques are discarded. Exhaustive search techniques can be used to solve the optimization problem, but when the number of parameters or the size of the computational system increases, the method is impracticable due to time restrictions. The use of approximation methods to guide the search is also an alternative. However, the dependence on the algorithm modeled and the bad quality of the solutions as a result of the presence of many local optima values in the objective functions are also drawbacks to these techniques. The problem becomes particularly difficult in complex systems hosting a large number of heterogeneous processors solving non-trivial scientific applications. The use of metaheuristics allows for the development of valid approaches to solve general problems with a large number of parameters. A well-known advantage of metaheuristic methods is the ability to obtain high-quality solutions at low running times while maintaining generality. We propose combining the parameterized analytical cost model function and metaheuristic minimization methods, which contributes to a novel real alternative to minimize the parallel execution time in complex systems. The success of the proposed approach is shown with two different algorithmic schemes on parallel heterogeneous systems. Furthermore, the development of a general framework allows us to easily develop and experiment with different metaheuristics to adjust them to particular problems.     

Linguistic measures for automatic machine translation evaluation

Assessing the quality of candidate translations involves diverse linguistic facets. However, most automatic evaluation methods in use today rely on limited quality assumptions, such as lexical similarity. This introduces a bias in the development cycle which in some cases has been reported to carry very negative consequences. In order to tackle this methodological problem, we explore a novel path towards heterogeneous automatic Machine Translation evaluation. We have compiled a rich set of specialized similarity measures operating at different linguistic dimensions and analyzed their individual and collective behaviour over a wide range of evaluation scenarios. Results show that measures based on syntactic and semantic information are able to provide more reliable system rankings than lexical measures, especially when the systems under evaluation are based on different paradigms. At the sentence level, while some linguistic measures perform better than most lexical measures, some others perform substantially worse, mainly due to parsing problems. Their scores are, however, suitable for combination, yielding a substantially improved evaluation quality.     

Hydroformylation of Alkenes with Rhodium Catalyst in Supercritical Carbon Dioxide

1-Octene, 1-decene and styrene have been hydroformylated using a CO₂-philic fluorous ligand associated with a rhodium catalyst. The effect of P/Rh molar ratio, partial pressure of CO/H₂ and total pressure of carbon dioxide were studied. When 1-octene was used as the substrate, high conversion and selectivity in aldehydes were observed using low rhodium concentration and low P/Rh ratios.     

Land use,travel utility and travel behaviour: An analysis from the perspective of the positive utility of travel

The concept of travel utility is refined by reflecting two positive aspects, derived utility and synergy–intrinsic utility. The refined utility – comprising the positive utility aspects and disutility as represented by trip time – is specified in a model for a comparison with a reference model that is based on the derived demand perspective. The comparison is made by structural equation modelling according to different travel purposes and measures. Notable findings are that land use affects travel behaviour mainly by improving positive utility, which leads to fewer shopping and more leisure trips, while disutility increase, not reduction, complements modal shift for commuting.     

Factors determining the photovoltaic performance of a CdSe quantum dot sensitized solar cell: the role of the linker molecule and of the counter electrode

Colloidal CdSe quantum dots (QDs) of different sizes, prepared by a solvothermal route, have been employed as sensitizers of nanostructured TiO(2) electrode based solar cells. Three different bifunctional linker molecules have been used to attach colloidal QDs to the TiO(2) surface: mercaptopropionic acid (MPA), thioglycolic acid (TGA), and cysteine. The linker molecule plays a determinant role in the solar cell performance, as illustrated by the fact that the incident photon to charge carrier generation efficiency (IPCE) could be improved by a factor of 5-6 by using cysteine with respect to MPA. The photovoltaic properties of QD sensitized electrodes have been characterized for both three-electrode and closed two-electrode solar cell configurations. For three-electrode measurement a maximum power conversion efficiency near?1% can be deduced, but this efficiency is halved in the closed cell configuration mainly due?to?the decrease of the fill factor (FF).