Biodegradation of linear alkylbenzene sulfonates and their degradation intermediates in seawater

A study has been made of the aerobic biodegradation of linear alkylbenzene sulfonates (C12 and C11 homologues) and sulfophenylcarboxylic acids (C5 and C11 homologues) in seawater at concentrations of the same order as those detected ones in coastal waters influenced by wastewater effluents, at different temperatures, and both with and without the addition of an inoculum adapted to the presence of linear alkylbenzene sulfonate (LAS). The biodegradation of C12LAS, C11LAS, C5SPC, and C11SPC exceeds 99% in all tests performed and can be satisfactorily fitted to a second-degree polynomial without an independent term. The kinetic of degradation of LAS presents a clear seasonal component, since the process is considerably inhibited at lower temperatures; it is also kinetically enhanced by the presence of the inoculum. The intermediates detected for all the cases are sulfophenylcarboxylic acids (SPCs), the most abundant being those intermediates produced by the omega- and beta-oxidations of the parent compound, although intermediates produced by the alpha-oxidation have also been detected. The kinetic of the SPCs generated can be described using a model composed of two terms that represent the formation and the degradation of these intermediates. The total disappearance of the SPCs in all cases indicates that the degradation of LAS in seawater at the tested concentrations in aerobic conditions is complete.     

Merging a DSP-Oriented Signal Integrity Technique and SW-Based Fault Handling Mechanisms to Ensure Reliable DSP Systems

Hereafter, we present an approach aiming to improve the reliability of digital signal processing (DSP) systems operating in real noisy (electromagnetic interference—EMI) environments. The approach is based on the coupling of two techniques: the DSP-oriented signal integrity improvement technique deals with increasing the signal-to-noise ratio (SNR) and is essentially a modification of the classic Recovery Blocks Scheme. The second technique, named SW-based fault handling aims to detect in real-time data- and control-flow faults throughout modifications of the processor code. When compared to conventional approaches using Fast Fourier Transform (FFT) and Hamming Code, the primary benefit of such an approach is to improve system reliability by means of a considerably low complexity, reasonably low performance degradation and, when implemented in hardware, with reduced area overhead. Aiming to illustrate the proposed approach, we implemented a HW/SW prototype to operate as a speech recognition system (SRS). This prototype was tested under a home-tailored EMI environment according to the IEC 61000-4-29 International Standard Normative. The obtained results indicate that the proposed approach can effectively improve the reliability of DSP systems operating in real noise (EMI) environments.     

Correlation between mercury and selenium concentrations in Indian hair from Rondĵnia State, Amazon region, Brazil

Total mercury and selenium concentrations were determined in hair samples collected from Wari (Pacaás Novos) Indians living in Doutor Tanajura village, Gujará-Mirim city, Rond?nia State. The mercury concentrations in some samples are much higher than the values determined in samples from individuals not exposed to mercury contamination, occupationally or environmentally. The selenium concentrations are in the normal range. A correlation was observed between the mercury and selenium concentration and the values of the molar ratio approach 1 at low Hg concentrations. This fact is related to the equimolar complex formed by [(Hg-Se)n]m-Seleprotein P, which can decrease the bioavailable mercury in the organism.     

Human exposure to mercury in San Jorge river basin,Colombia (South America)

During May-September 1999 human hair samples were collected from the village of Caimito, a fishing community of the state of Sucre (Colombia), in the San Jorge River basin area, and analyzed for total mercury (t-Hg) by cold vapor atomic absorption spectroscopy. T-Hg was measured in both male and female people aged 15-65 years, whose diet mainly consists of fish collected in nearby marshes. Average hair t-Hg concentration in people from Caimito was 4.91 +/- 0.55 microg/g (n = 94), similar to the value previously detected in fishermen living in the gold mining area, 50 km east. Males had similar t-Hg concentrations (4.31 +/- 0.42 microg/g; n = 56) to females (5.78 +/- 1.21 microg/g; n = 38) and there was no difference in t-Hg levels between groups of different age. Mercury content in hair was weakly but significantly associated (R = 0.20, P = 0.05) with fish consumption.     

Conformal Geometric Algebra for Robotic Vision

In this paper the authors introduce the conformal geometric algebra in the field of visually guided robotics. This mathematical system keeps our intuitions and insight of the geometry of the problem at hand and it helps us to reduce considerably the computational burden of the problems. As opposite to the standard projective geometry, in conformal geometric algebra we can deal simultaneously with incidence algebra operations (meet and join) and conformal transformations represented effectively using spinors. In this regard, this framework appears promising for dealing with kinematics, dynamics and projective geometry problems without the need to resort to different mathematical systems (as most current approaches do). This paper presents real tasks of perception and action, treated in a very elegant and efficient way: body–eye calibration, 3D reconstruction and robot navigation, the computation of 3D kinematics of a robot arm in terms of spheres, visually guided 3D object grasping making use of the directed distance and intersections of lines, planes and spheres both involving conformal transformations. We strongly believe that the framework of conformal geometric algebra can be, in general, of great advantage for applications using stereo vision, range data, laser, omnidirectional and odometry based systems. Eduardo Jose Bayro-Corrochano gained his Ph.D. in Cognitive Computer Science in 1993 from the University of Wales at Cardiff. From 1995 to 1999 he has been Researcher and Lecturer at the Institute for Computer Science, Christian Albrechts University, Kiel, Germany, working on applications of geometric Clifford algebra to cognitive systems.  His current research interest focuses on geometric methods for artificial perception and action systems. It includes geometric neural networks, visually guidevsd robotics, color image processing, Lie bivector algebras for early vision and robot maneuvering. He is editor and author of the following books: Geometric Computing for Perception Action Systems, E. Bayro-Corrochano, Springer Verlag, 2001; Geometric Algebra with Applications in Science and Engineering, E. Bayro-Corrochano and G. Sobczyk (Eds.), Birkahauser 2001; Handbook of Computational Geometry for Pattern Recognition, Computer Vision, Neurocomputing and Robotics, E. Bayro-Corrochano, Springer Verlag, 2005. He authored more than 90 strictly reviewed papers. Leo Hendrick Reyes-Lozano received his degree in Computer Engineering from the University of Guadalajara in 1999. He earned his MSc. and Ph.D. from the Center of Research and Advanced Studies (CINVESTAV) Guadalajara in 2001 and 2004, respectively. His research interests include Computer Vision, Geometric Algebra and Computer Graphics. Julio Zamora-Esquivel received his degree in Electronic Engineering at the Guzman City Institute of Tecnology in 2000. He earned his MSc. at the Center of Research and Advanced Studies (CINVESTAV) in Guadalajara in 2003. He is currently a Ph.D Candidate at CINVESTAV. His research interests include Computer Vision, Geometric Algebra and Robotics.     

Evaluating the reliability of computational grids from the end user’s point of view

Reliability, in terms of Grid component fault tolerance and minimum quality of service, is an important aspect that has to be addressed to foster Grid technology adoption. Software reliability is critically important in today’s integrated and distributed systems, as is often the weak link in system performance. In general, reliability is difficult to measure, and specially in Grid environments, where evaluation methodologies are novel and controversial matters. This paper describes a straightforward procedure to analyze the reliability of computational grids from the viewpoint of an end user. The procedure is illustrated in the evaluation of a research Grid infrastructure based on Globus basic services and the GridWay meta-scheduler. The GridWay support for fault tolerance is also demonstrated in a production-level environment. Results show that GridWay is a reliable workload management tool for dynamic and faulty Grid environments. Transparently to the end user, GridWay is able to detect and recover from any of the Grid element failure, outage and saturation conditions specified by the reliability analysis procedure.     

Stable methods for recognizing acronym-expansion pairs: from rule sets to hidden Markov models

A significant portion of currently available documents exist in the form of images, for instance, as scanned documents. Electronic documents produced by scanning and OCR software contain recognition errors. This paper uses an automatic approach to examine the selection and the effectiveness of searching techniques for possible erroneous terms for query expansion. The proposed method consists of two basic steps. In the first step, confused characters in erroneous words are located and editing operations are applied to create a collection of erroneous error-grams in the basic unit of the model. The second step uses query terms and error-grams to generate additional query terms, identify appropriate matching terms, and determine the degree of relevance of retrieved document images to the user's query, based on a vector space IR model. The proposed approach has been trained on 979 document images to construct about 2,822 error-grams and tested on 100 scanned Web pages, 200 advertisements and manuals, and 700 degraded images. The performance of our method is evaluated experimentally by determining retrieval effectiveness with respect to recall and precision. The results obtained show its effectiveness and indicate an improvement over standard methods such as vectorial systems without expanded query and 3-gram overlapping. Youssef Fataicha received his B.Sc. degree from Université de Rennes1, Rennes, France, in 1982. In 1984 he obtained his M.Sc. in computer science from Université de Rennes1, France. Between 1984 and 1986 he was a lecturer at the Université de Rennes1, France. He then served as engineer, from 1987 to 2000, at {Office de l'eau potable et de l'électricité} in Morocco. Since 2001 has been a Ph.D. student at the {école de Technologie Supérieure de l'Université du Québec} in Montreal, Québec, Canada. His research interests include pattern recognition, information retrieval, and image analysis. Mohamed Cheriet received his B.Eng. in computer science from {Université des Sciences et de Technologie d'Alger} (Bab Ezouar, Algiers) in 1984 and his M.Sc. and Ph.D., also in computer science, from the University of Pierre et Marie Curie (Paris VI) in 1985 and 1988, respectively. Dr. Cheriet was appointed assistant professor in 1992, associate professor in 1995, and full professor in 1998 in the Department of Automation Engineering, {école de Technologie Supérieure} of the University of Québec, Montreal. Currently he is the director of LIVIA, the Laboratory for Imagery, Vision and Artificial Intelligence at ETS, and an active member of CENPARMI, the Centre for Pattern Recognition and Machine Intelligence. Professor Cheriet's research focuses on mathematical modeling for signal and image processing (scale-space, PDEs, and variational methods), pattern recognition, character recognition, text processing, document analysis and recognition, and perception. He has published more than 100 technical papers in these fields. He was the co-chair of the 11th and the 13th Vision Interface Conferences held respectively in Vancouver in 1998 and in Montreal in 2000. He was also the general co-chair of the 8th International Workshop on Frontiers on Handwriting Recognition held in Niagara-on-the-Lake in 2002. He has served as associate editor of the International Journal of Pattern Recognition and Artificial Intelligence (IJPRAI) since 2000. Dr. Cheriet is a senior member of IEEE. Jian Yun Nie is a professor in the computer science department (DIRO), Université de Montreal, Québec, Canada. His research focuses on problems related to information retrieval, including multilingual and multimedia information retrieval, as well as natural language processing. Ching Y. Suen received his M.Sc. (Eng.) from the University of Hong Kong and Ph.D. from the University of British Columbia, Canada. In 1972 he joined the Department of Computer Science of Concordia University, where he became professor in 1979 and served as chairman from 1980 to 1984 and as associate dean for research of the Faculty of Engineering and Computer Science from 1993 to 1997. He has guided/hosted 65 visiting scientists and professors and supervised 60 doctoral and master's graduates. Currently he holds the distinguished Concordia Research Chair in Artificial Intelligence and Pattern Recognition and is the Director of CENPARMI, the Centre for Pattern Recognition and Machine Intelligence.Professor Suen is the author/editor of 11 books and more than 400 papers on subjects ranging from computer vision and handwriting recognition to expert systems and computational linguistics. A Google search on “Ching Y. Suen” will show some of his publications. He is the founder of the International Journal of Computer Processing of Oriental Languages and served as its first editor-in-chief for 10 years. Presently he is an associate editor of several journals related to pattern recognition.A fellow of the IEEE, IAPR, and the Academy of Sciences of the Royal Society of Canada, he has served several professional societies as president, vice-president, or governor. He is also the founder and chair of several conference series including ICDAR, IWFHR, and VI. He has been the general chair of numerous international conferences, including the International Conference on Computer Processing of Chinese and Oriental Languages in August 1988 held in Toronto, International Conference on Document Analysis and Recognition held in Montreal in August 1995, and the International Conference on Pattern Recognition held in Québec City in August 2002.Dr. Suen has given 150 seminars at major computer companies and various government and academic institutions around the world. He has been the principal investigator of 25 industrial/government research contracts and is a grant holder and recipient of prestigious awards, including the ITAC/NSERC award from the Information Technology Association of Canada and the Natural Sciences and Engineering Research Council of Canada in 1992 and the Concordia “Research Fellow” award in 1998.     

Lessons from a PV pumping programme in south Morocco

This paper presents the experience of a PV pumping project being carried‐out in the South of Morocco since 1997. At present, the project has reached 18 villages, affecting 15 000 people. Total involved photovoltaic power is 46 kW_p, and the total volume of pumped water since the installation of the systems approaches 0.7 × 10⁶ m³. About half the PV systems are based on dedicated inverters, while the rest are based on standard frequency drivers. Both perform very similarly in terms of both efficiency and reliability. Wells have been selected to provide good water taste, and pumped water is distributed to all the individual houses. Average daily water consumption in summer varies from 13 to 50 litres per person depending on ease of water access and ‚urban proximity’︁. The maintenance infrastructure is based on an agreement between the European supplier company and a local NGO, which is in charge of all the local organizations. Copyright © 2005 John Wiley & Sons, Ltd.     

Interesterification of tallow and sunflower oil

The objective of this study was to manufacture a shortening using chemical interesterification (IT) of tallow-sunflower oil blends to replace fish oil in the present formulation, which is now in short supply in Chile. The significant variables of the IT process were obtained by 2⁴⁻¹ fractional factorial design. The proportion of tallow (T) in the blend, catalyst concentration, and reaction temperature had a significant effect on the melting point (mp) (P≤0.05). IT of tallow and sunflower oil blends (90∶10 and 70∶30) diminished the mp, dropping point, and refractive index compared to tallow. However, a noninteresterified 90∶10 blend mp was not significantly different from tallow. IT produced a solid fat content (SFC) profile of IT90∶10 blend that was appropriate for use in shortenings for the baking industry. Blending and IT of the 90∶10 blend increased the melting profile of the tallow and the melting range from −40 to 60°C while the endotherms of the middle-melting triacylglycerols (TAG) decreased. The IT90∶10 blend hardnesswas 70% lower than tallow hardness, and the crystal network was composed of large spherulites in a network. IT resulted in an appropriate method to improve physical properties of tallow, whereas blending did not significantly modify it. The interesterification changed the SFC profile of IT90∶10, giving a more appropriate shortening for use in the baking industry.     

Bioreactors Based on Monolith‐Supported Ionic Liquid Phase for Enzyme Catalysis in Supercritical Carbon Dioxide

Bioreactors with covalently supported ionic liquid phases (SILP) were prepared as polymeric monoliths based on styrene–divinylbenzene or 2‐hydroxyethyl methacrylate–ethylene dimethacrylate, and with imidazolium units loadings ranging from 54.7 to 39.8 % wt IL per gram of polymer. The SILPs were able to absorb Candida antarctica lipase B (CALB), leading to highly efficient and robust heterogeneous biocatalysts. The bioreactors were prepared as macroporous monolithic mini‐flow systems and tested for the continuous flow synthesis of citronellyl propionate in supercritical carbon dioxide (scCO₂) by transesterification. The catalytic activity of these mini‐flow‐bioreactors remained practically unchanged for seven operational cycles of 5 h each in different supercritical conditions. The best results were obtained when the most hydrophobic monolith, M‐SILP‐ 8 ‐CALB, was assayed at 80 °C and 10 M Pa, reaching a total turnover number (TON) of 35.8×10⁴ mol product/mol enzyme. The results substantially exceeded those obtained for packed‐bed reactors with supported silica‐CALB‐Si‐4 catalyst under the same experimental conditions.