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Selected AbstractsSuspended sediment load estimation and the problem of inadequate data sampling: a fractal viewEARTH SURFACE PROCESSES AND LANDFORMS, Issue 4 2006Bellie Sivakumar Abstract Suspended sediment load estimation at high resolutions is an extremely difficult task, because: (1) it depends on the availability of high-resolution water discharge and suspended sediment concentration measurements, which are often not available; (2) any errors in the measurements of these two components could significantly influence the accuracy of suspended sediment load estimation; and (3) direct measurements are very expensive. The purpose of this study is to approach this sampling problem from a new perspective of fractals (or scaling), which could provide important information on the transformation of suspended sediment load data from one scale to another. This is done by investigating the possible presence of fractal behaviour in the daily suspended sediment load data for the Mississippi River basin (at St. Louis, Missouri). The presence of fractal behaviour is investigated using five different methods, ranging from general to specific and from mono-fractal to multi-fractal: (1) autocorrelation function; (2) power spectrum; (3) probability distribution function; (4) box dimension; and (5) statistical moment scaling function. The results indicate the presence of multi-fractal behaviour in the suspended sediment load data, suggesting the possibility of transformation of data from one scale to another using a multi-dimensional model. Copyright © 2005 John Wiley & Sons, Ltd. [source] Human immunodeficiency virus-associated diffuse non-Hodgkin's lymphoma in Venezuelan patients: treatment with full-dose cyclophosphamide-doxorubicin-vincristine-prednisone without routine use of granulocyte-colony stimulating factorEUROPEAN JOURNAL OF CANCER CARE, Issue 5 2006D.E. HERNÀNDEZ md, phd The routine use of granulocyte-colony stimulating factor (G-CSF) for 10 days during full-dose cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP) chemotherapy in HIV-associated diffuse non-Hodgkin's lymphoma (NHL) patients is very expensive in developing countries. We treated 22 HIV-associated diffuse NHL patients with standard-dose CHOP and used G-CSF after an episode of febrile neutropenia until neutrophil count reached 1000/mm3. The clinical response was: complete response (36%), partial response (32%), stable disease (14%) and progression (18%). There were no toxicity-related deaths. Grade 3 or 4 neutropenia was observed in 16% of cycles, but only 8% were complicated with febrile neutropenia. Seventeen patients died (median survival 15 months; range 2,70). There are five patients alive (median survival 24+ months; range 17,36+). Our experience showed that we can treat HIV-related NHL patients with full-dose CHOP, achieve good responses and have an acceptable toxicity profile, with the use of G-CSF as needed. [source] Gene therapy for haemophilia,yes, but,with non-viral vectors?HAEMOPHILIA, Issue 3 2009A. LIRAS Summary., High-purity plasma-derived and recombinant factors are currently safe and efficient treatment for haemophilia. The mid-term future of haemophilia treatment will involve the use of modified recombinant factors to achieve advantages such as decreased immunogenicity in inhibitor formation and enhanced efficacy as a result of their longer half-life. In the long-term, gene therapy and cell therapy strategies will have to be considered. Achievements in cell therapy to date have been using embryonic stem cells and hepatic sinusoidal endothelial cells. Current gene therapy strategies for haemophilia are based on gene transfer using adeno-associated viruses and non-viral vectors. Gene therapy for haemophilia is justified because it is a chronic disease and because a very regular factor infusion is required that may involve fatal risks and because it is very expensive. Haemophilia is a very good candidate for use of gene therapy protocols because it is a monogenic disease, and even low expression is able to achieve reversion from a severe to a moderate phenotype. The current trends in haemophilia using adeno-associated viral vectors are safe but also involve immunogenicity problems. The other alternatives are non-viral vectors. There have been in recent years relevant advances in non-viral transfection that raise hope for considering this possibility. Several research groups are opting for this experimental alternative. An expression over 5%, representing a moderate phenotype, for a few months with a high safety, regarding vector, transfected cells, and implantation procedure, would already be a great success. This may represent an intermediate protocol in which the expression levels and times obtained are lower and shorter respectively as compared to viral vectors, but which provide a potential greater patient safety. This may more readily win acceptance among both patients and haematologists because fatal events in the past due to HIV/HCV infection may constrain the implementation of viruses as vectors. [source] Orthogonality of modal bases in hp finite element modelsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2007V. Prabhakar Abstract In this paper, we exploit orthogonality of modal bases (SIAM J. Sci. Comput. 1999; 20:1671,1695) used in hp finite element models. We calculate entries of coefficient matrix analytically without using any numerical integration, which can be computationally very expensive. We use properties of Jacobi polynomials and recast the entries of the coefficient matrix so that they can be evaluated analytically. We implement this in the context of the least-squares finite element model although this procedure can be used in other finite element formulations. In this paper, we only develop analytical expressions for rectangular elements. Spectral convergence of the L2 least-squares functional is verified using exact solution of Kovasznay flow. Numerical results for transient flow over a backward-facing step are also presented. We also solve steady flow past a circular cylinder and show the reduction in computational cost using expressions developed herein. Copyright © 2007 John Wiley & Sons, Ltd. [source] Parallel computation of a highly nonlinear Boussinesq equation model through domain decompositionINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 1 2005Khairil Irfan Sitanggang Abstract Implementations of the Boussinesq wave model to calculate free surface wave evolution in large basins are, in general, computationally very expensive, requiring huge amounts of CPU time and memory. For large scale problems, it is either not affordable or practical to run on a single PC. To facilitate such extensive computations, a parallel Boussinesq wave model is developed using the domain decomposition technique in conjunction with the message passing interface (MPI). The published and well-tested numerical scheme used by the serial model, a high-order finite difference method, is identical to that employed in the parallel model. Parallelization of the tridiagonal matrix systems included in the serial scheme is the most challenging aspect of the work, and is accomplished using a parallel matrix solver combined with an efficient data transfer scheme. Numerical tests on a distributed-memory super-computer show that the performance of the current parallel model in simulating wave evolution is very satisfactory. A linear speedup is gained as the number of processors increases. These tests showed that the CPU time efficiency of the model is about 75,90%. Copyright © 2005 John Wiley & Sons, Ltd. [source] A simple and low-cost solution for the automation of X-ray powder diffractometers with chart recorder outputJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2006M. Jayaprakasan X-ray powder diffraction is an established method for the qualitative identification of crystalline materials and their quantitative analysis. The new generation of X-ray diffraction systems are based on expensive digital/embedded control technology and computer interfaces. Yet many laboratories use conventional manual-controlled systems with XY strip-chart recorders. Since the output spectrum is a strip chart (hard copy), raw data, essential for structural and qualitative analysis, are not readily available for further analysis. Upgrading to modern computerized diffractometers is very expensive. The proposed automation design described here is intended to enable the conventional diffractometer user to collect, store and analyze data quickly. The design also improves the resolution by five times compared with the conventional setup. For the automation, a PC add-on card has been designed to control and collect the timing and intensity counts from the conventional X-ray diffractometer, and suitable software has been developed to collect, process and present the X-ray diffraction data for both qualitative and quantitative analysis. Moreover, a major advantage of this design is that it does not warrant any physical modification of the hardware of the conventional setup; it is simply an extension to enhance the performance of collecting raw data with a higher resolution at desired intervals/timings. [source] Shopping for E-LearningJOURNAL OF CORPORATE ACCOUNTING & FINANCE, Issue 5 2001Craig Hannas Corporate training for employees and executives is vital in today's quickly changing market. However, it can be very expensive. But a new solution is revolutionizing corporate training and slashing costs: online training, or e-learning. The author explains how it works and gives advice on how to shop for an e-learning provider. © 2001 John Wiley & Sons, Inc. [source] QUARTZ-TUNGSTEN-HALOGEN AND LIGHT-EMITTING DIODE CURING LIGHTSJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 3 2006Kraig S. Vandewalle DDS Curing lights are an integral part of the daily practice of restorative dentistry. Quartz-tungsten-halogen (QTH), plasma-arc (PAC), argon laser, and light-emitting diode (LED) curing lights are currently commercially available. The QTH curing light has a long, established history as a workhorse for composite resin polymerization in dental practices and remains the most common type of light in use today. Its relatively broad emission spectrum allows the QTH curing light to predictably initiate polymerization of all known photo-activated resin-based dental materials. However, the principal output from these lamps is infrared energy, with the generation of high heat. Filters are used to reduce the emitted heat energy and provide further restriction of visible light to correlate better with the narrower absorbance spectrum of photo-initiators. The relatively inefficient emission typically requires corded handpieces with noisy fans. PAC lights generate a high voltage pulse that creates hot plasma between two electrodes in a xenon-filled bulb. The irradiance of PAC lights is much higher than the typical QTH curing light, but PAC lights are more expensive and generate very high heat with an inefficient emission spectrum similar to that of QTH bulbs. Light emitted from an argon laser is very different from that emitted from the halogen or PAC lights. The photons produced are coherent and do not diverge; therefore, lasers concentrate more photons of specific frequency into a tiny area. With very little infrared output, unwanted heat is minimized. However, argon lasers are very expensive and inefficient due to a small curing tip. LED curing lights have been introduced to the market with the promise of more efficient polymerization, consistent output over time without degradation, and less heat emission in a quiet, compact, portable device. This review evaluates some of the published research on LED and QTH curing lights. [source] INDIVIDUAL AND COMBINED CYTOTOXIC EFFECTS OF THE MAJOR FOUR AFLATOXINS IN DIFFERENT IN VITRO STABILIZED SYSTEMSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2010CORNELIA BRAICU ABSTRACT The present study aims to investigate the cytotoxic effect of the major aflatoxins (B1, B2, G2 and G2) and also aflatoxin combination, using a simple, rapid and cheap cytotoxicity test like MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay in three in vitro models (human umbilical vein endothelial cells [HUVEC], human lung fibroblasts [HFL] and A2780 cell line) and to extrapolate the data to in vivo situation using a prediction model. A difference in cell sensitivity has been observed for B1 and B1 + B2, in the following order A2789 > HFL > HUVEC, while for B2, G1, G2, Mix (B1 + B2 + G1 + G2) the order was HFL > A2789 > HUVEC when comparing the IC50 (half maximal inhibitory concentration) values. We confirm that in vitro cytotoxicity test MTT assay is able to predict in vivo toxicity, at least for aflatoxins using the prediction model. The values of LD50 (lethal dose 50%) calculated from experiments are different for each cell line. This fact may indicate that some species are more resistant than other and target organs are not necessarily those predicted, because the A2780 ovarian cancer cells seem to be more sensitive to B1 than cells of endothelial or fibroblasts origin. PRACTICAL APPLICATIONS This study is in concordance with the international tendency that refined the current techniques to lessen pain or distress, to reduce the number of animals necessary for a particular test or to replace animals with non-whole-animal models, such as in vitro cell cultures. The practical application of such methodologies may help solve the economic problem related to very expensive in vivo toxicology studies and implement preventive methods based on the calculated data and known mechanism of action of individual or combined toxins easily studied in vitro. The nature of coexistence of many types of mycotoxins in complex environmental samples, such as food and water, has been reported worldwide. How these mycotoxins might affect human health in combination is largely unknown. This study had, as a goal, to test the toxicity of the four aflatoxins and aflatoxin combination on human cells. Due to the lack of aflatoxins mixture data regarding the human cytotoxicity, the aim of this study was to specify, evaluate and predict the combined effects of mycotoxin mixtures. [source] RANDOM APPROXIMATED GREEDY SEARCH FOR FEATURE SUBSET SELECTIONASIAN JOURNAL OF CONTROL, Issue 3 2004Feng Gao ABSTRACT We propose a sequential approach called Random Approximated Greedy Search (RAGS) in this paper and apply it to the feature subset selection for regression. It is an extension of GRASP/Super-heuristics approach to complex stochastic combinatorial optimization problems, where performance estimation is very expensive. The key points of RAGS are from the methodology of Ordinal Optimization (OO). We soften the goal and define success as good enough but not necessarily optimal. In this way, we use more crude estimation model, and treat the performance estimation error as randomness, so it can provide random perturbations mandated by the GRASP/Super-heuristics approach directly and save a lot of computation effort at the same time. By the multiple independent running of RAGS, we show that we obtain better solutions than standard greedy search under the comparable computation effort. [source] Synthesis and assembly of a full-length human monoclonal antibody in algal chloroplastsBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2009Miller Tran Abstract Monoclonal antibodies can be effective therapeutics against a variety of human diseases, but currently marketed antibody-based drugs are very expensive compared to other therapeutic options. Here, we show that the eukaryotic green algae Chlamydomonas reinhardtii is capable of synthesizing and assembling a full-length IgG1 human monoclonal antibody (mAb) in transgenic chloroplasts. This antibody, 83K7C, is derived from a human IgG1 directed against anthrax protective antigen 83 (PA83), and has been shown to block the effects of anthrax toxin in animal models. Here we show that 83K7C heavy and light chain proteins expressed in the chloroplast accumulate as soluble proteins that assemble into complexes containing two heavy and two light chain proteins. The algal-expressed 83K7C binds PA83 in vitro with similar affinity to the mammalian-expressed 83K7C antibody. In addition, a second human IgG1 and a mouse IgG1 were also expressed and shown to properly assemble in algal chloroplast. These results show that chloroplasts have the ability to fold and assemble full-length human mAbs, and suggest the potential of algae as a platform for the cost effective production of complex human therapeutic proteins. Biotechnol. Bioeng. 2009; 104: 663,673 © 2009 Wiley Periodicals, Inc. [source] Plant-based corosolic acid: Future anti-diabetic drug?BIOTECHNOLOGY JOURNAL, Issue 12 2009Ganapathy Sivakumar Abstract Diabetes is one of the nation's most prevalent, debilitating and costly diseases. For diabetes, frequent insulin treatment is very expensive and may increase anti-insulin antibody production, which may cause unwanted side effects. Corosolic acid may also have some efficacy in the treatment of diabetes, but without induction of anti-insulin antibodies. Recently, corosolic acid from Lagerstroemia speciosa L. leaf extracts has been reported to act via an indirect mechanism (unlike insulin) in animal experiments. The insulin-complementary anti-diabetic therapeutic value observed in these Japanese preliminary clinical trials has led to renewed interest in the biosynthesis of this compound. So far, there has been no clear evidence for a corosolic acid biosynthetic pathway in plants. This article provides possible roles of corosolic acid and hypothetical information on the biosynthetic pathway in plants. [source] Representative marketing-oriented study on implants in the Austrian population.CLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2003Abstract: Oral implantology is an established subspecialty of restorative dental and oral surgery. While an extensive body of evidence on the fundamentals of osseointegration and associated factors has been published, marketing-oriented analyses based on representative public opinion polls of implant acceptance, patient-perceived cost and patient satisfaction are scarce. In this study, an attempt was made to address these points by questioning a representative sample of 1000 adults in the household setting. The interviewees were presented with 14 questions. Of those familiar with implants as one of the treatment alternatives, 61% reported they would accept implants if the need arose. Implant acceptance was highest among males and interviewees below the age of 30 years. The interest in implants increased with increasing family incomes. Four percent of those questioned already had implants. Twenty-five percent knew someone who had undergone implant treatment. All those questioned found implant-supported rehabilitation to be very expensive. Many of them blamed the dentists for the high cost. One detail was particularly evident: satisfaction among implanted patients was clearly higher than satisfaction rates perceived by them from what they were told about implants by others. First-hand experiences with implants proved to be less biased than reported second-hand information. Résumé L'implantologie buccale est une technique appliquée dans certaines spécialités de médecine dentaire. Tandis que la proportion d'évidences s'accroît en ce qui concerne la recherche sur l'ostéoïntégration et les facteurs associés, les analyses orientées sur le marketing et l'opinion du public sur l'acceptation de l'implant, le prix et la satisfaction se font rares. Cette étude a été réalisée pour analyser ces différents points via un échantillon de 1 000 adultes. Les interviewés ont répondu à quatorze questions. De ceux qui étaient familiers à l'idée que les implants pouvaient être une alternative au traitement, 61 % ont répondu qu'ils pourraient si nécessaire y recourir. L'acceptation de l'implant était plus importante chez les hommes et les personnes âgées de moins de trente ans. L'intérêt à propos des implants augmentait parallèlement aux revenus de la famille. Quatre pour cent des personnes étaient déjà porteurs d'implants. Vingt-cinq pour cent connaîssaient une personne ayant subi un traitement d'implant buccal. Parmi toutes les personnes interrogées, la réhabilitation sur implants semblait trop chère. Beaucoup d'entre-eux rejetaient la responsabilité des prix trop élevés sur les dentistes. Un détail était particulièrement évident : la satisfaction parmi les patients possèdant des implants était clairement plus importante que le taux de satisfaction perçu par ceux n'en portant pas mais ayant reçu l'information par d'autres personnes. L'expérience personnelle était moins déformée que celle obtenue de manière indirecte. Zusammenfassung Die orale Implantologie ist eine etablierte Subspezialität der restaurativen Zahnmedizin und der Oralchirurgie. Während extensive Evidenz über die Grundlagen der Osseointegration und der assoziierten Faktoren publiziert worden ist, sind marketing-orientierte Analysen basierend auf repräsentativen Meinungsumfragen über die Akzeptanz von Implantaten, über die von Patienten empfundenen Kosten und über die Patientenzufriedenheit rar. In dieser Studie wird der Versuch unternommen, diese Punkte mit Hilfe einer Befragung einer repräsentativen Gruppe von 1000 Erwachsenen anzusprechen. Den Befragten wurden 14 Fragen gestellt. Von denen, welche über Implantate als Behandlungsalternative Bescheid wussten, gaben 61% an, sie würden Implantate bei sich akzeptieren, falls die Notwendigkeit dafür besteht. Die Akzeptanz von Implantaten war bei Männern und Befragten unter 30 Jahren am grössten. Das Interesse an Implantaten nahm mit zunehmendem Familieneinkommen zu. Vier Prozent der Befragten hatten bereits Implantate. Fünfundzwanzig Prozent kannten jemanden, der sich einer Implantation unterzogen hat. Alle Befragten empfanden Implantatversorgungen zu kostspielig. Viele davon fanden, der Zahnarzt sei schuld an den hohen Kosten. Ein Detail war von besonderem Interesse: Die Zufriedenheit bei mit Implantaten versorgten Patienten war deutlich grösser als die von anderen Leuten empfundene Zufriedenheit, welche über Implantatversorgung von anderen gehört haben. Erfahrungen mit Implantaten aus erster Hand waren mit weniger Vorurteilen behaftet als Informationen aus zweiter Hand, über die berichtet wurde. Resumen La implantología oral es una subespecialidad establecida de restauración dental y cirugía oral. Mientras que se ha publicado una gran cantidad de evidencias sobre los fundamentos de la osteointegración y factores asociados, los análisis orientados al marketing basados en encuestas representativas de la opinión pública sobre aceptación de los implantes, costo percibido por el paciente y satisfacción del paciente son escasos. En este estudio se hizo un intento de dirigir estos puntos encuestando una muestra representativa de 1000 adultos en su hogar. A los entrevistados se les presentaron 14 preguntas. De aquellos familiarizados con los implantes como una de las alternativas de tratamiento, el 61% respondió que aceptarían los implantes llegada la necesidad. La aceptación de los implantes fue mayor en varones y entrevistados menores de 30 años. El interés en los implantes creció con ingresos familiares crecientes. El 4% de los encuestados ya tenían implantes. El 25% conocía a alguien que se había sometido a tratamiento de implantes. Todos los encuestados encontraron la rehabilitación con implantes demasiado cara. Muchos de ellos culparon a los dentistas del alto costo. Un detalle fue particularmente evidente: La satisfacción entre los pacientes implantados fue claramente mas alta que los índices de satisfacción percibidos por ellos de lo que se les dijo sobre los implantes por otros. Las experiencias de primera mano con implantes demostraron ser menos viciadas que las informaciones reportadas de segunda mano. [source] | |||||||||||||||||||