bluuebunny/crossref_metadata_2025 huggingface dataset:
National Treatment and the Choice Between Exports and FDI
Authors: Hoekman Bernard , Saggi Kamal
Published: December 2005

International trade agreements increasingly constrain the ability of governments to use trade policies. Fewer international constraints apply to the use of investment policies, although there is discussion about negotiating such disciplines both regionally and multilaterally. Since firms compete in foreign markets via both exports and foreign direct investment(FDI), the following question arises: can constraints on the use of only one type of policy (trade or FDI) induce firms to adopt inefficient modes of supply when serving foreign markets? We address this question in a model in which a local and a foreign firm compete in the domestic market. In the model, the domestic government's trade and/or FDI policies as well as the foreign firm's choice between exports and FDI are endogenous. We show that even if the domestic government is constrained only in its ability to use trade (FDI) policy, and is free to set its FDI (trade) policy, the foreign firm chooses the efficient mode of supply. The key point is that it is never in the interest of the domestic government to set policies in a manner that leads the foreign firm to adopt an inefficient mode of supply.
Real Options, Conflicting Valuations, and Favoritism
Authors: Arya Anil , Glover Jonathan
Published: December 2005

In this paper, limited managerial capacity gives rise to a timing option: agents can implement projects now-or-later. Because each agent cares only about the project he implements, while the principal cares about the projects undertaken in aggregate, the timing option may be valued differently by the principal and the agents. Under a fair assignment rule (one that treats the agents symmetrically), these conflicting valuations result in agents sometimes not implementing the principal's desired projects. We identify conditions under which the optimal assignment rule necessarily exhibits favoritism. Favoritism is beneficial because it provides appropriate incentives to the unfavored agent by reducing his option value of waiting.
The Selection Effects (and Lack Thereof) in Patent Litigation: Evidence from Trials
Authors: Marco Alan C.
Published: December 2005

Using a selection corrected probit, I estimate the probability that patents will be found valid and infringed at trial. I combine for the first time detailed adjudication data with detailed patent data. I find that the selection effects for validity adjudications and infringement adjudications differ systematically. Additionally, infringement estimates do not appear to suffer from a substantial selection bias. The results highlight the importance of correctly specifying the selection mechanism in policy analysis. In contrast with previous studies, I find that the win rate for patents that go to trial is biased towards 50%. The bias is much more substantial for validity decisions, where I find unconditional win rates of 75% for adjudicated patents and 85% for matched patents. Win rates conditional on adjudication are below 60%.
Media Competition on the Internet
Authors: Barros Pedro P , Kind Hans Jarle , Nilssen Tore , Sørgard Lars
Published: December 2005

We present a model of competition between two advertising-financed media firms when consumers dislike advertising. We apply the model to analyze competition between Internet portals and find that equilibrium prices of advertising are higher the less differentiated the portals are perceived to be. Moreover, we find that the portals' aggregate profit increases if they integrate vertically with advertisers. This is true even if there is perfect competition between advertisers for advertising space. But if the portals are close substitutes, then it is profitable for one of the portals not to combine with an advertiser, and we end up with an asymmetric equilibrium with only one vertical merger - despite aggregate profits being higher with two.
Statutory Interpretation as Diplomacy
Authors: Brudney James J.
Published: December 2005

There is every reason to admire the transformative analytic power of the DSI thesis: Professor Eskridge has persuasively identified the realities of what courts so often do. In this article, Professor Brudney raises questions about the dynamic role that Eskridge envisions for courts as a normative matter. Because DSI relies on post-enactment changes in the broader legal and ideological culture, it allows the judiciary to reshape legislatively determined priorities in light of exogenous legal and policy developments that are often enhanced, if not created, by the courts themselves. This approach tilts the meaning of statutes toward the policy preferences of the judiciary, especially given the predictable delay and difficulty that attend congressional responses to the courts' reshaping efforts. Brudney develops and illustrates his thesis through discussion of Supreme Court decisions interpreting federal workplace statutes.
Cooperative Investment and the Value of Contracting with Transaction Costs
Authors: Vercammen James
Published: December 2005

Bilateral exchange and asset specific investments are becoming increasingly common as agricultural markets continue to industrialize and become vertical coordinated. The extent that well-designed contracts can prevent investment holdup in bilateral exchange situations has been examined extensively in the general economics literature. Che and Hausch (1999) established the strong result that contracts have no value if the relationship specific investment is purely cooperative and if the contracting parties cannot commit to not renegotiate the contract ex post. In this paper, it is shown that contracts are generally valuable in a Che and Hausch environment if information between the seller and buyer is asymmetric and there is a cost to eliminating this asymmetry.
Tough Love: Optimal Enforcement of Output Quotas in the Presence of Cheating
Authors: Giannakas Konstantinos , Fulton Murray
Published: December 2005

This study builds on the literature on the economics of output quotas in the presence of cheating. We extend previous work by Giannakas and Fulton (2000a) by examining the decisions of the agency responsible for the enforcement of output quotas in a decentralized policy-making structure. Enforcement policy design is modeled as a sequential game between the agency that determines the enforcement of the quota program (designed by a regulator), and farmers who make production decisions. Analytical results show that the level of enforcement depends on the size of the enforcement costs and the political preferences of the enforcement agency - the greater is the weight placed by the enforcement agency on producer welfare, the greater is the level of program enforcement.
Pricing-to-Market versus Residual Demand Elasticity Analysis of Imperfect Competition in Food Exports: Evidence from Germany
Authors: Glauben Thomas , Loy Jens-Peter
Published: December 2005

This paper examines the exercise of market power by German food and beverage export industries over international markets. Two approaches are used: pricing-to-market (PTM) and residual demand elasticity (RDE). We find that, while in some cases the PTM approach indicates market power, the RDE approach does not. Competitive conduct seems to prevail in these industries. The occurrence of PTM in some cases might be explained by fixed contracts, which are often used in the food and beverage export market.
Contract Design: A Note on Cash Settled Futures
Authors: Manfredo Mark R , Sanders Dwight R
Published: December 2005

This note presents an intuitive interpretation and expression for pricing cash settled futures contracts. In particular, the choice of the averaging period for the underlying cash index is evaluated. A question arises as to how the choice of the averaging period may effect how the futures contract is priced. In this note, it is shown that under certain assumptions, the behavior of the futures price prior to entering the expiration interval is independent of the averaging intervals length for storable commodities. However, this is not the case for nonstorable commodities. An examination of the Minneapolis Grain Exchanges National Corn Index futures provides empirical support for the results. Given the increasing interest in cash settled futures, especially for futures contracts on agricultural commodities, these results should prove useful to futures exchanges when considering contract design. Ultimately, contract design choices are a critical factor in the success of any futures contract. In the context of agricultural futures contracts, successful contracts can contribute to increased social welfare and greater efficiency of the food marketing system.
Information Pooling and Collusion: Implications for The Livestock Mandatory Reporting Act
Authors: Njoroge Kenneth
Published: December 2005

This paper develops a conceptual model that analyzes the impact of increasing market transparency under the Livestock Mandatory Reporting Act of 1999 on the incentives for collusion in the U.S. meatpacking industry. More than likely, meatpackers will have asymmetric priors regarding the distribution of livestock prices. Moreover, they lack the incentives to voluntarily reveal their real priors. Thus, the enforcer of the Act faces a problem of asymmetric information regarding the informativeness of publicly disclosed market reports relative to that of packers priors. Analytical results predict that divergent priors of Bayesian packers can be updated by more informative market reports, so that the resultant posteriors converge, enabling packers to identify a more efficient, unanimous trigger price. This enhances observability of deviations from collusive behavior, and increases the internal policing efficiency by a cartel that employs trigger price strategies to monitor deviations by its members. Contrary to the Acts well-intended objectives, this is consistent with promoting collusion and decreasing market efficiency.
Industrial Development and Operation of an Efficient Riser Separation System for FCC Units
Authors: Gauthier Thierry , Andreux Regis , Verstraete Jan , Roux Romain , Ross Jay
Published: December 2005

With over 300 units in operation, Fluid Catalytic Cracking (FCC) is currently the dominant refinery conversion process. Over the last years, rapid separation of hydrocarbon vapors and catalyst at the riser outlet has been put forward to limit non-selective decomposition of reaction products, thus enhancing product selectivities.A new riser separator system, called RS², was developed to minimize post-riser cracking, while maintaining flexibility of operation. The development included cold flow testing, CFD and pilot plant testing, and aimed at minimizing both thermal degradation and catalytic overcracking. Cold flow testing was conducted at a representative scale (scale 1/10th) on a large cold flow mock-up. Testing various riser separator configurations provided a thorough understanding, both through visual observations, pressure drop measurements and tracer studies. Hot pilot plant testing was conducted to investigate the effect on yields of the riser separation system in the reactor-stripper under adiabatic operation as a function of operating conditions. The separator had a significant impact on the FCC heat balance and a large reduction of dry gas yield was observed.The resulting technology was successfully implemented on an industrial resid catalytic cracking unit. Operation of the separator was proven smooth and flexible with enhanced performance, while the industrial observations confirm the R&D conclusions. This paper therefore summarizes the R&D study and the industrial operation trends. In particular, the impact of stripper bed level on operation is discussed and explained based on the flow phenomena and design aspects.
Characterization of Homogeneity of Bubble Flows in Bubble Columns Using RPT and Fibre Optics
Authors: Xu Sikun , Qu Yuhui , Chaouki Jamal , Guy Christophe
Published: December 2005

Homogeneous flows of air-water in two bubble columns, 0.130 m and 0.292 m in diameter, were investigated using RPT (radioactive particle tracking) and fibre optics. The homogeneity of bubble flows at U g < 0.04 m/s was revealed not only in the hydrodynamics of the gas/liquid phase but also in the transport phenomena (turbulence intensity). RPT Lagrangian data derived that turbulence was about 0.15 m/s for the radial direction and 0.26~0.35 m/s for axial direction in the 0.292 m column, 0.05~0.16 m/s for the radial direction and 0.25~0.35 m/s for the axial direction in the 0.13 column. Average bubble diameter was 4~5.3 mm and was almost constant for the radial locations. The result was twice the sizes of the predicted bubble sizes in the CFD modeling. The slip velocity was 0.3 m/s at U g=0.015~0.033m/s as it was assumed in many reactor designs, and only a small variation was found at the radial locations. In flow patterns, stable circulation cells were revealed using velocity vector plots if a single nozzle sparger was used in the 0.13m column, which confirmed Joshis assumptions (Joshi and Sharma, 1979) and Lins assumption (Lin et al., 1996) based on 2-D columns. Using a perforated sparger was helpful to form a stable mean velocity field. Mean bubble diameters and bubble size distribution varied only slightly with radial/axial locations, which was consistent with the homogeneity of radial/axial turbulence. Bubble-size evolution from their formation to equilibrium mean diameter was discussed. Mean bubble size correlation was approached. The homogeneity of investigated flows was also substantiated by the criteria of stability for bubble flows.
Use of CFD for Wastewater Disinfection Process Analysis: E.coli Inactivation with Peroxyacetic Acid (PAA)
Authors: Santoro Domenico , Bartrand Timothy A. , Greene Dennis J. , Farouk Bakhtier , Haas Charles N. , Notarnicola Michele , Liberti Lorenzo
Published: December 2005

Historically, the priority in disinfection reactor design has been microbial inactivation with a high factor of safety, neglecting other processes such as disinfection byproduct (DBP) formation and chemical use minimization. With heightened awareness and regulation of DBPs, advanced chemical engineering principles and practices are being employed in disinfection process analysis and design in order to minimize DBP production while ensuring sufficient microbial inactivation. Computational fluid dynamics (CFD) is increasingly popular as a tool to evaluate reactor performance and assess design concepts. This study presents the results of CFD analyses of two disinfection reactors with very different aspect ratios and design, but being characterized by the same theoretical hydraulic residence time (i.e., 30 minutes). Both reactors were used to inactivate E. coli with the novel disinfectant peroxyacetic acid (PAA). CFD calculations were performed for inactivation of E. coli (10000 CFU/100 mL) with PAA concentrations of 4 and 8 mg/L. Calculations were carried out for two serpentine reactors with aspect ratios (channel width to water depth) of 2:1 and 1:3. In the second reactor, perforated baffle plates were placed at the end of each channel in an attempt to promote uniform flow. Both reactors achieved adequate removal of organisms, but displayed non-ideal hydrodynamics, with significant recirculation regions that reduced the volume available for reaction and promoted short-circuiting. CFD simulations emphasized that reactor hydrodynamics impacts on the specific disinfection performances inducing different ratio of reactor volume active during the disinfection process.
Evaluation of Multiple Models to Distinguish Closely Related Forms of Disease Using DNA Microarray Data: an Application to Multiple Myeloma
Authors: Hardin Johanna , Waddell Michael , Page C. David , Zhan Fenghuang , Barlogie Bart , Shaughnessy John , Crowley John J
Published: December 2005

Motivation: Standard laboratory classification of the plasma cell dyscrasia monoclonal gammopathy of undetermined significance (MGUS) and the overt plasma cell neoplasm multiple myeloma (MM) is quite accurate, yet, for the most part, biologically uninformative. Most, if not all, cancers are caused by inherited or acquired genetic mutations that manifest themselves in altered gene expression patterns in the clonally related cancer cells. Microarray technology allows for qualitative and quantitative measurements of the expression levels of thousands of genes simultaneously, and it has now been used both to classify cancers that are morphologically indistinguishable and to predict response to therapy. It is anticipated that this information can also be used to develop molecular diagnostic models and to provide insight into mechanisms of disease progression, e.g., transition from healthy to benign hyperplasia or conversion of a benign hyperplasia to overt malignancy. However, standard data analysis techniques are not trivial to employ on these large data sets. Methodology designed to handle large data sets (or modified to do so) is needed to access the vital information contained in the genetic samples, which in turn can be used to develop more robust and accurate methods of clinical diagnostics and prognostics.

Results: Here we report on the application of a panel of statistical and data mining methodologies to classify groups of samples based on expression of 12,000 genes derived from a high density oligonucleotide microarray analysis of highly purified plasma cells from newly diagnosed MM, MGUS, and normal healthy donors. The three groups of samples are each tested against each other. The methods are found to be similar in their ability to predict group membership; all do quite well at predicting MM vs. normal and MGUS vs. normal. However, no method appears to be able to distinguish explicitly the genetic mechanisms between MM and MGUS. We believe this might be due to the lack of genetic differences between these two conditions, and may not be due to the failure of the models. We report the prediction errors for each of the models and each of the methods. Additionally, we report ROC curves for the results on group prediction.

Availability: Logistic regression: standard software, available, for example in SAS. Decision trees and boosted trees: C5.0 from www.rulequest.com. SVM: SVM-light is publicly available from svmlight.joachims.org. Naïve Bayes and ensemble of voters are publicly available from www.biostat.wisc.edu/~mwaddell/eov.html. Nearest Shrunken Centroids is publicly available from http://www-stat.stanford.edu/~tibs/PAM.
Using Alpha Wisely: Improving Power to Detect Multiple QTL
Authors: Simonsen Katy L , McIntyre Lauren M
Published: December 2005

The increase in the number of available markers for many experimental populations has led to QTL studies with ever increasing marker numbers and densities. The resulting conundrum is that as marker density increases, so does the multiple testing problem. It is important to re-examine the detection of multiple QTL in light of increasing marker density. We explore through simulation whether existing methods have achieved the maximum possible power for detecting multiple QTL and whether increasing the marker density is an effective strategy for locating multiple QTL. In addition to existing methods, such as the maximum, the CET, and the Benjamini-Hochberg and Benjamini-Yekutieli procedures, we propose and evaluate the complete set of order statistics with their corresponding empirical joint distribution. We examine these statistics in conjunction with a novel application of the alpha-spending approach, providing a less conservative solution to the problem of controlling the false discovery rate (FDR) in multiple tests. We conducted a simulation study to assess the relative power of these approaches as well as their ability to control FDR. We find that several of the new approaches have a reasonable FDR, and can substantially improve the experimenter's ability to detect multiple QTL compared to existing approaches in many cases; however, the Benjamini-Hochberg procedure remains a very reasonable choice. The methods are applied to a nine-trait Oat vernalization dataset.
Linear Models and Empirical Bayes Methods for Assessing Differential Expression in Microarray Experiments
Authors: Smyth Gordon K
Published: December 2005

The problem of identifying differentially expressed genes in designed microarray experiments is considered. Lonnstedt and Speed (2002) derived an expression for the posterior odds of differential expression in a replicated two-color experiment using a simple hierarchical parametric model. The purpose of this paper is to develop the hierarchical model of Lonnstedt and Speed (2002) into a practical approach for general microarray experiments with arbitrary numbers of treatments and RNA samples. The model is reset in the context of general linear models with arbitrary coefficients and contrasts of interest. The approach applies equally well to both single channel and two color microarray experiments. Consistent, closed form estimators are derived for the hyperparameters in the model. The estimators proposed have robust behavior even for small numbers of arrays and allow for incomplete data arising from spot filtering or spot quality weights. The posterior odds statistic is reformulated in terms of a moderated t-statistic in which posterior residual standard deviations are used in place of ordinary standard deviations. The empirical Bayes approach is equivalent to shrinkage of the estimated sample variances towards a pooled estimate, resulting in far more stable inference when the number of arrays is small. The use of moderated t-statistics has the advantage over the posterior odds that the number of hyperparameters which need to estimated is reduced; in particular, knowledge of the non-null prior for the fold changes are not required. The moderated t-statistic is shown to follow a t-distribution with augmented degrees of freedom. The moderated t inferential approach extends to accommodate tests of composite null hypotheses through the use of moderated F-statistics. The performance of the methods is demonstrated in a simulation study. Results are presented for two publicly available data sets.
Augmentation Procedures for Control of the Generalized Family-Wise Error Rate and Tail Probabilities for the Proportion of False Positives
Authors: van der Laan Mark J. , Dudoit Sandrine , Pollard Katherine S.
Published: December 2005

This article shows that any single-step or stepwise multiple testing procedure (asymptotically) controlling the family-wise error rate (FWER) can be augmented into procedures that (asymptotically) control tail probabilities for the number of false positives and the proportion of false positives among the rejected hypotheses. Specifically, given any procedure that (asymptotically) controls the FWER at level alpha, we propose simple augmentation procedures that provide (asymptotic) level-alpha control of: (i) the generalized family-wise error rate, i.e., the tail probability, gFWER(k), that the number of Type I errors exceeds a user-supplied integer k, and (ii) the tail probability, TPPFP(q), that the proportion of Type I errors among the rejected hypotheses exceeds a user-supplied value 0
Sparse Inverse of Covariance Matrix of QTL Effects with Incomplete Marker Data
Authors: Thallman R. Mark , Hanford Kathryn J , Kachman Stephen D , Van Vleck L. Dale
Published: December 2005

Gametic models for fitting breeding values at QTL as random effects in outbred populations have become popular because they require few assumptions about the number and distribution of QTL alleles segregating. The covariance matrix of the gametic effects has an inverse that is sparse and can be constructed rapidly by a simple algorithm, provided that all individuals have marker data, but not otherwise. An equivalent model, in which the joint distribution of QTL breeding values and marker genotypes is considered, was shown to generate a covariance matrix with a sparse inverse that can be constructed rapidly with a simple algorithm. This result makes more feasible including QTL as random effects in analyses of large pedigrees for QTL detection and marker assisted selection. Such analyses often use algorithms that rely upon sparseness of the mixed model equations and require the inverse of the covariance matrix, but not the covariance matrix itself. With the proposed model, each individual has two random effects for each possible unordered marker genotype for that individual. Therefore, individuals with marker data have two random effects, just as with the gametic model. To keep the notation and the derivation simple, the method is derived under the assumptions of a single linked marker and that the pedigree does not contain loops. The algorithm could be applied, as an approximate method, to pedigrees that contain loops.
A Method for Evaluating the Impact of Individual Haplotypes on Disease Incidence in Molecular Epidemiology Studies
Authors: Venkatraman E. S , Mitra Nandita , Begg Colin B
Published: December 2005

Estimation of the association between haplotypes and disease from a case-control study is considered. Assuming a single “disease haplotype" leads to the increased risk, attention focusses on the relative risks associated with a single copy, or two copies of the disease haplotype, relative to individuals with no copies. In this setting, case frequencies of the haplotype pairs are in Hardy-Weinberg Equilibrium (HWE) only if the combined influence of the two copies of the disease haplotype on risk is multiplicative. Thus, imputation cannot rely on the assumption of HWE for cases. A method is presented for obtaining estimates of the relative risks, making use of the EM algorithm and the assumption of HWE only for controls. The method accounts for the additional variation in the estimates due to the imputation of expected frequencies of haplotype pairs from ambiguous genotypes. A simulation study shows that the resulting confidence intervals have nominal coverage, and that the methods based on the assumption of HWE for both cases and controls can lead to bias.
Reader Reaction
Authors: Foulkes Andrea S , De Gruttola Victor
Published: December 2005

This note is a response to the article "relating HIV-1 sequence variation to replication capacity via trees and forests" that appeared in Statistical Applications in Genetics and Molecular Biology, 3(1): http://www.bepress.com/sagmb/vol3/iss1/art2,2004
BayesMendel: an R Environment for Mendelian Risk Prediction
Authors: Chen Sining , Wang Wenyi , Broman Karl W , Katki Hormuzd A , Parmigiani Giovanni
Published: December 2005

Several important syndromes are caused by deleterious germline mutations of individual genes. In both clinical and research applications it is useful to evaluate the probability that an individual carries an inherited genetic variant of these genes, and to predict the risk of disease for that individual, using information on his/her family history. Mendelian risk prediction models accomplish these goals by integrating Mendelian principles and state-of-the-art statistical models to describe phenotype/genotype relationships. Here we introduce an R library called BayesMendel that allows implementation of Mendelian models in research and counseling settings. BayesMendel is implemented in an object-oriented structure in the language R and distributed freely as an open source library. In its first release, it includes two major cancer syndromes: the breast-ovarian cancer syndrome and the hereditary non-polyposis colorectal cancer syndrome, along with up-to-date estimates of penetrance and prevalence for the corresponding genes. Input genetic parameters can be easily modified by users. BayesMendel can also serve as a generic tool for genetic epidemiologists to flexibly implement their own Mendelian models for novel syndromes and local subpopulations, without reprogramming complex statistical analyses and prediction tools.
Error Distribution for Gene Expression Data
Authors: Purdom Elizabeth , Holmes Susan P
Published: December 2005

We present a new instance of Laplace's second Law of Errors and show how it can be used in the analysis of data from microarray experiments. This error distribution is shown to fit microarray expression data much better than a normal distribution. The use of this distribution in a parametric bootstrap leads to more powerful tests as we show that the t-test is conservative in this setting. We propose a biological explanations for this distribution based on the Pareto distribution of the variables used to compute the log ratios.
Increasing Power for Tests of Genetic Association in the Presence of Phenotype and/or Genotype Error by Use of Double-Sampling
Authors: Gordon Derek , Yang Yaning , Haynes Chad , Finch Stephen J , Mendell Nancy R , Brown Abraham M , Haroutunian Vahram
Published: December 2005

Phenotype and/or genotype misclassification can: significantly increase type II error probabilities for genetic case/control association, causing decrease in statistical power; and produce inaccurate estimates of population frequency parameters. We present a method, the likelihood ratio test allowing for errors (LRTae) that incorporates double-sample information for phenotypes and/or genotypes on a sub-sample of cases/controls. Population frequency parameters and misclassification probabilities are determined using a double-sample procedure as implemented in the Expectation-Maximization (EM) method. We perform null simulations assuming a SNP marker or a 4-allele (multi-allele) marker locus. To compare our method with the standard method that makes no adjustment for errors (LRTstd), we perform power simulations using a 2^k factorial design with high and low settings of: case/control samples, phenotype/genotype costs, double-sampled phenotypes/genotypes costs, phenotype/genotype error, and proportions of double-sampled individuals. All power simulations are performed fixing equal costs for the LRTstd and LRTae methods. We also consider case/control ApoE genotype data for an actual Alzheimer's study.

The LRTae method maintains correct type I error proportions for all null simulations and all significance level thresholds (10%, 5%, 1%). LRTae average estimates of population frequencies and misclassification probabilities are equal to the true values, with variances of 10e-7 to 10e-8. For power simulations, the median power difference LRTae-LRTstd at the 5% significance level is 0.06 for multi-allele data and 0.01 for SNP data. For the ApoE data example, the LRTae and LRTstd p-values are 5.8 x 10e-5 and 1.6 x 10e-3, respectively. The increase in significance is due to adjustment in the LRTae for misclassification of the most commonly reported risk allele. We have developed freely available software that performs our LRTae statistic.
Comparing Automatic and Manual Image Processing in FLARE Assay Analysis for Colon Carcinogenesis
Authors: Leyk Malgorzata , Nguyen Danh V , Attoor Sanju N , Dougherty Edward R , Turner Nancy D , Bancroft Laura K , Chapkin Robert S , Lupton Joanne R , Carroll Raymond J
Published: December 2005

Measurement of the amount of oxidative damage to DNA is one tool that can be used to estimate the beneficial effect of diet on the prevention of colon carcinogenesis. The FLARE assay is a modification of the single-cell gel electrophoresis (Comet) assay, and provides a measure of the 8OHdG adduct in the cells. In this paper, we present two innovations to the existing methods of analysis. The first one is related to the FLARE assay itself. We describe automated image analysis techniques that can be expected to measure oxidative damage faster, reproducibly, with less noise, and hence achieve greater statistical power. The proposed technique is compared to an existing technique, which was more manual and thus slower. The second innovation is our statistical analysis: we exploit the shape of FLARE intensity histograms, and show statistically significant diet effects in the duodenum. Previous analyses of this data concentrated on simple summary statistics, and found only marginally statistically significant diet effects. With the new imaging method and measure of oxidative damage, we show cells in the duodenum exposed to fish oil as having more oxidative damage than cells exposed to corn oil.
Extension of the SIMLA Package for Generating Pedigrees with Complex Inheritance Patterns: Environmental Covariates, Gene-Gene and Gene-Environment Interaction
Authors: Schmidt Mike , Hauser Elizabeth R , Martin Eden R. , Schmidt Silke
Published: December 2005

We have previously distributed a software package, SIMLA (SIMulation of Linkage and Association), which can be used to generate disease phenotype and marker genotype data in three-generational pedigrees of user-specified structure. To our knowledge, SIMLA is the only publicly available program that can simulate variable levels of both linkage (recombination) and linkage disequilibrium (LD) between marker and disease loci in general pedigrees. While the previous SIMLA version provided flexibility in choosing many parameters relevant for linkage and association mapping of complex human diseases, it did not allow for the segregation of more than one disease locus in a given pedigree and did not incorporate environmental covariates possibly interacting with disease susceptibility genes.Here, we present an extension of the simulation algorithm characterized by a much more general penetrance function, which allows for the joint action of up to two genes and up to two environmental covariates in the simulated pedigrees, with all possible multiplicative interaction effects between them. This makes the program even more useful for comparing the performance of different linkage and association analysis methods applied to complex human phenotypes. SIMLA can assist investigators in planning and designing a variety of linkage and association studies, and can help interpret results of real data analyses by comparing them to results obtained under a user-controlled data generation mechanism.A free download of the SIMLA package is available at http://wwwchg.duhs.duke.edu/software.
Structured Antedependence Models for Functional Mapping of Multiple Longitudinal Traits
Authors: Zhao Wei , Hou Wei , Littell Ramon C. , Wu Rongling
Published: December 2005

In this article, we present a statistical model for mapping quantitative trait loci (QTL) that determine growth trajectories of two correlated traits during ontogenetic development. This model is derived within the maximum likelihood context, incorporated by mathematical aspects of growth processes to model the mean vector and by structured antedependence (SAD) models to approximate time-dependent covariance matrices for longitudinal traits. It provides a quantitative framework for testing the relative importance of two mechanisms, pleiotropy and linkage, in contributing to genetic correlations during ontogeny. This model has been employed to map QTL affecting stem height and diameter growth trajectories in an interspecific hybrid progeny of Populus, leading to the successful discovery of three pleiotropic QTL on different linkage groups. The implications of this model for genetic mapping within a broader context are discussed.
Herbal Remedies: The Good, The Bad, and The Ugly
Authors: Philp Richard B.
Published: December 2005

In recent years the use of herbal remedies has increased in western society, bringing withit an increase in the risk and frequency of adverse effects and interactions with conventional prescription and proprietary medications. Problems asociated with herbal remedies include lack of quality control, lack of government regulations regarding safety and efficacy, a paucity of clinical trials and inadequate information on adverse effects and drug-herbal interactions. This article discusses these problems in the context the historical evolution of botanical-source medications and reviews problems associated with specific herbals including those with serious toxicity such as ephedra, borage, coltsfoot and calamus, as well as those with demonstrated interactions with conventional drugs such as St. John's wort. Mechanisms are discussed where known. Some two dozen individual herbs are tabulated with respect to their traditional use, pharmacological activity and potential for interactions. The potential for herbal remedies to serve as a source for new prescription drugs is also discussed.
Regulatory System of Proprietary Chinese Medicine in Hong Kong
Authors: Leung Kelvin Sze-Yin , Chan Kelvin
Published: December 2005

Traditional medicine has been used by a significant percentage of the population not only in the Western Pacific Region but also in a lot of Asian countries [1]. A review article published earlier in Hong Kong revealed that an estimation of about 60% of the local population has experience of consulting traditional medicine practitioner or using Chinese medicinal products [2]. The increasing use of traditional medicine implies that the demand for a well-established regulatory policy becomes imminence. In Hong Kong, the Legislative Council has passed the Chinese Medicine Ordinance in 1999 with aims to regulate the practice, use, trading and manufacture of Chinese medicine [3]. A list of the first batch of registered Chinese medicine practitioners was published in the Gazette on November 2002 [3]. A project entitled Hong Kong Chinese Materia Medica Standards that focuses on safety and quality standards for Chinese medicinal materials was launched in the same year and being developed. Two local universities have been invited for participation in the first phase of this project [4]. Licensing of Chinese medicines traders has been implemented in 2003 and registration of proprietary Chinese medicines has also been introduced recently. According to the Chinese Medicine Ordinance, all proprietary Chinese medicines in Hong Kong should subject for initial registration before 30 June 2004. All those required documentations and test reports should arrive the Chinese Medicines Board within the transition period. No person shall sell, import or possess any proprietary Chinese medicines in Hong Kong unless it is registered.
Developing a National Vision for Complementary and Alternative Medicine in Undergraduate Medical Education: Report on an Invitational Workshop
Authors: Verhoef Marja J. , Epstein Michael , Brundin-Mather Rebecca
Published: December 2005

The increasing use of Complementary and Alternative Medicine (CAM) among Canadians has led to exploring the potential role of CAM in undergraduate medical education (UME). As part of a multi-phased project to begin developing CAM curriculum for UME, representatives of 14 Canadian medical schools attended a two day workshop in September 2003 in Saskatoon, SK. Workshop outcomes included developing (1) a rationale for CAM in UME, (2) draft student learning objectives, (3) a list of potential CAM curriculum topics, and (4) a list of factors affecting curriculum implementation. Much of the discussions centred on what Canadas future physicians need to know about CAM. Broad curricular categories included (1) general CAM topics (e.g., definitions, utilization, reasons for use, evidence, implications for practice, bridging paradigms), and (2) specific CAM products and practices. The top rated practice areas for physicians to know about were Natural Health Products, Traditional Chinese Medicine, chiropractic, naturopathy and homeopathy. Participants identified that for each of these practices/products a descriptive overview, information about evidence, safety and regulation, and clinical implications needs to be discussed. Using the workshop recommendations as a foundation, the CAM in UME project team continues to develop a national, consensus-based CAM curriculum for Canadian medical schools.
From Bench to Bedside to Consumer: Where are the Regulatory Problems for Probiotics?
Authors: Reid Gregor
Published: December 2005

Probiotics is a field of science, medicine and business that is growing rapidly. Regulatory agencies, especially in North America, are slow to understand these concepts and embrace and enforce United Nations and World Health Organization Guidelines. In order to advance the science and efficacy of probiotics, industry needs to self-regulate and ensure that high standards of products are met, then trials must be performed on human subjects using appropriate sample size, design and target population. With the support of granting agencies, such studies will provide valuable information on the efficacy and limitations of probiotics, and the mechanisms by which they confer their activity. In addition, regulatory authorities need to establish and enforce a standard of identity and only allow products to be called probiotic if sufficient documentation is generated.
Public Attitudes Towards Chinese Medicine in Melbourne, Australia
Authors: Xue Charlie CL , Lee Clifton , Karagiannis Joanna , Li Chunguang , Yang Angela WH , Zhang Lin , Story David F
Published: December 2005

Purpose: To investigate the public attitudes towards Chinese medicine and the impact of the introduction of statutory practitioner registration in Melbourne, Australia. Method: A convenience sample of 575 participants (18-45 years of age) from three locations in Melbourne completed a self-administered, 60-question survey in August 2002. Results: In the previous 12 months, Chinese medicine had been used by 30.9% of the respondents and 17.3% had visited a Chinese medicine practitioner. For each of eight common conditions listed in the survey, between 61.2% and 92.7% of participants indicated that western medicine was their preferred therapeutic option, rather than Chinese medicine or combination of Western and Chinese medicine. However, substantial proportions of participants preferred Chinese medicine for stomach or internal problems (28.4%), cold/flu (18.8%) and dizziness (17.6%). Although 78.2% were aware that statutory practitioner registration had recently been introduced in the State, only 29.9% indicated that they would only visit a registered practitioner. Implication: More stringent surveillance of Chinese medicine service providers and a public education campaign may be necessary to protect against unauthorized Chinese medicine practice.
Transmission Congestion Management and Pricing in Simple Auction Electricity Markets
Authors: Canizares Claudio A , Chen Hong , Milano Federico , Singh Ajit
Published: December 2005

This paper presents a novel technique to analyze, manage and price transmission congestion in electricity markets based on a simple auction mechanism. The proposed technique is basically an iterative rescheduling algorithm, relying on an ``on-line'' evaluation of the transmission system congestion, as defined by a System Security Index (SSI), and associated sensitivities, which are all computed based on formulas that account for voltage stability constraints as well as thermal and bus voltage limits. The methodology is tested using a 3-area test system, a 6-bus test system with both demand-side bidding and inelastic demand, as well as a 129-bus model of the Italian High Voltage transmission system with demand-side bidding. The results obtained for these test systems with the proposed technique are compared with similar results obtained from an optimization-based method.
Role of Fuzzy Sets in Power System State Estimation
Authors: Shahidehpour Mohammad , marwali muhammad
Published: December 2005

This paper presents an enhancement to the least median of squares (LMS) estimation in the power system state estimation. A weighted least square estimation may be used in conjunction with LMS, yet LMS could face difficulties for eliminating bad data in specific cases. The proposed method, denoted as fuzzy LMS+LAV estimation, employs the applications of fuzzy sets to improve the accuracy of LMS. The proposed method applies the LMS method to determine the bounds of residuals and then applies fuzzy sets to the least absolute value (LAV) estimator to eliminate bad data. The paper shows that the proposed method produces more accurate estimate of power system states than that of LMS. The complementary advantages of fuzzy LAV and LMS estimators without lengthy computational efforts, which are targeted by this paper include: * less computational effort than the fuzzy LAV. * better accuracy than LMS. * same if not better robustness than both estimators. A qualitative comparison illustrates the superior robustness of the proposed method in the presence of leverage bad data.
Placement and Penetration of Distributed Generation under Standard Market Design
Authors: Agalgaonkar A. P. , Kulkarni S. V. , Khaparde S. A. , Soman S. A.
Published: December 2005

Distributed Generation (DG) can help in reducing the cost of electricity to the costumer, relieve network congestion and provide environmentally friendly energy close to load centers. Its capacity is also scalable and it provides voltage support at distribution level. Hence, DG placement and penetration level is an important problem for both the utility and DG owner. The cost of electricity as a commodity depends upon market model. The restructured power markets are slowly maturing with standardizations like Standard Market Design (SMD). The key feature of SMD is the Locational Marginal Pricing (LMP) scheme. This paper examines placement and penetration level of the DGs under the SMD framework. The proposed approach is illustrated by case studies on MATPOWER 30 bus and IEEE 118 bus systems.
Assessment of Risk involved with Bidding Strategies of a Genco in a Day Ahead Market
Authors: Karandikar R. G. , Abhyankar A. R. , Khaparde S. A. , Nagaraju P.
Published: December 2005

In a deregulated power industry a Genco bids in the optimal fashion in a day ahead market. The net gain is decided by Market Clearing Price (MCP) which in turn is dictated by other participants and prevailing market conditions. In this paper, the feasible set of bid strategies is evaluated for risk. Risk is quantified as the variation from expected amount of return from the market settlements for an hour. The problem is formulated for multiple participants using efficient frontier method. The risk evaluation is done for two sample systems with three and six Gencos. The results help in choosing a maximum return with minimum risk policy.
Power System Disturbance Recognition Using Wavelet and S-Transform Techniques
Authors: Reddy Jaya Bharata , Mohanta Dusmanta Kumar , Karan B.M.
Published: December 2005

Power quality issues have been a source of major concern in recent years due to extensive use of power electronic devices and non-linear loads in electrical power system and consequently sensitive detection and accurate classification of power disturbances have become very much necessary. To monitor electrical power quality disturbances, short time discrete Fourier transform (STFT) is most often used. But for non- stationary signals, the STFT does not track the signal dynamics properly due to the limitations of a fixed window width chosen a priori. This paper presents a new approach for power quality analysis using a modified wavelet transform, known as Stransform and the analysis of several power quality problems using both Stransform as well as discrete wavelet transform validates the superiority of Stransform.
Component Model for Multi- Area Power Systems On-Line Economic Load Dispatch
Authors: Kannan K.Nithiyananthan , Veilumuthu V.Ramachandran
Published: December 2005

The main objective of this paper is to develop component model architecture for economic load dispatch of multi - area power systems. A component which is based on a single-server serving multiple clients has been proposed which enables all neighboring power systems to have simultaneous access to the remote economic load dispatch server for obtaining continuous load dispatch solutions. An EJB (Enterprise Java Beans) based, distributed environment has been implemented in such a way that each power system client can access the remote economic load dispatch EJB server through JNDI (Java Naming and Directory Interface) naming service with its power system data. The server computes the economic load dispatch and it provides the continuous automated load dispatch solutions to all the registered power system clients. Economic load dispatch EJB server inherently creates a new thread of control for every client request and hence complete component based distributed environment can be achieved.