bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion synthesis from annotations
Authors: Arikan Okan , Forsyth David A. , O'Brien James F.
Published: October 2003

This paper describes a framework that allows a user to synthesize human motion while retaining control of its qualitative properties. The user paints a timeline with annotations --- like walk, run or jump --- from a vocabulary which is freely chosen by the user. The system then assembles frames from a motion database so that the final motion performs the specified actions at specified times. The motion can also be forced to pass through particular configurations at particular times, and to go to a particular position and orientation. Annotations can be painted positively (for example,
must
run), negatively (for example,
may not
run backwards) or as a
don't-care
. The system uses a novel search method, based around dynamic programming at several scales, to obtain a solution efficiently so that authoring is interactive. Our results demonstrate that the method can generate smooth, natural-looking motion.The annotation vocabulary can be chosen to fit the application, and allows specification of composite motions (run and jump simultaneously, for example). The process requires a collection of motion data that has been annotated with the chosen vocabulary. This paper also describes an effective tool, based around repeated use of support vector machines, that allows a user to annotate a large collection of motions quickly and easily so that they may be used with the synthesis algorithm.
Efficient synthesis of physically valid human motion
Authors: Fang Anthony C. , Pollard Nancy S.
Published: October 2003

Optimization is a promising way to generate new animations from a minimal amount of input data. Physically based optimization techniques, however, are difficult to scale to complex animated characters, in part because evaluating and differentiating physical quantities becomes prohibitively slow. Traditional approaches often require optimizing or constraining parameters involving joint torques; obtaining first derivatives for these parameters is generally an
O
(
D
2
) process, where
D
is the number of degrees of freedom of the character. In this paper, we describe a set of objective functions and constraints that lead to linear time analytical first derivatives. The surprising finding is that this set includes constraints on physical validity, such as ground contact constraints. Considering only constraints and objective functions that lead to linear time first derivatives results in fast per-iteration computation times and an optimization problem that appears to scale well to more complex characters. We show that qualities such as squash-and-stretch that are expected from physically based optimization result from our approach. Our animation system is particularly useful for synthesizing highly dynamic motions, and we show examples of swinging and leaping motions for characters having from 7 to 22 degrees of freedom.
Sensation preserving simplification for haptic rendering
Authors: Otaduy Miguel A. , Lin Ming C.
Published: October 2003

We introduce a novel "sensation preserving" simplification algorithm for faster collision queries between two polyhedral objects in haptic rendering. Given a polyhedral model, we construct a multiresolution hierarchy using " filtered edge collapse", subject to constraints imposed by collision detection. The resulting hierarchy is then used to compute fast contact response for haptic display. The computation model is inspired by human tactual perception of contact information. We have successfully applied and demonstrated the algorithm on a time-critical collision query framework for haptically displaying complex object-object interaction. Compared to existing exact contact query algorithms, we observe noticeable performance improvement in update rates with little degradation in the haptic perception of contacts.
Building efficient, accurate character skins from examples
Authors: Mohr Alex , Gleicher Michael
Published: October 2003

Good character animation requires convincing skin deformations including subtleties and details like muscle bulges. Such effects are typically created in commercial animation packages which provide very general and powerful tools. While these systems are convenient and flexible for artists, the generality often leads to characters that are slow to compute or that require a substantial amount of memory and thus cannot be used in interactive systems. Instead, interactive systems restrict artists to a specific character deformation model which is fast and memory efficient but is notoriously difficult to author and can suffer from many deformation artifacts. This paper presents an automated framework that allows character artists to use the full complement of tools in high-end systems to create characters for interactive systems. Our method starts with an arbitrarily rigged character in an animation system. A set of examples is exported, consisting of skeleton configurations paired with the deformed geometry as static meshes. Using these examples, we fit the parameters of a deformation model that best approximates the original data yet remains fast to compute and compact in memory.
Animating suspended particle explosions
Authors: Feldman Bryan E. , O'Brien James F. , Arikan Okan
Published: October 2003

This paper describes a method for animating suspended particle explosions. Rather than modeling the numerically troublesome, and largely invisible blast wave, the method uses a relatively stable incompressible fluid model to account for the motion of air and hot gases. The fluid's divergence field is adjusted directly to account for detonations and the generation and expansion of gaseous combustion products. Particles immersed in the fluid track the motion of particulate fuel and soot as they are advected by the fluid. Combustion is modeled using a simple but effective process governed by the particle and fluid systems. The method has enough flexibility to also approximate sprays of burning liquids. This paper includes several demonstrative examples showing air bursts, explosions near obstacles, confined explosions, and burning sprays. Because the method is based on components that allow large time integration steps, it only requires a few seconds of computation per frame for the examples shown.
Image-based skin color and texture analysis/synthesis by extracting hemoglobin and melanin information in the skin
Authors: Tsumura Norimichi , Ojima Nobutoshi , Sato Kayoko , Shiraishi Mitsuhiro , Shimizu Hideto , Nabeshima Hirohide , Akazaki Syuuichi , Hori Kimihiko , Miyake Yoichi
Published: October 2003

This paper proposes an E-cosmetic function for digital images based on physics and physiologically-based image processing. A practical skin color and texture analysis/synthesis technique is introduced for this E-cosmetic function. Shading on the face is removed by a simple color vector analysis in the optical density domain as an inverse lighting technique. The image without shading is analyzed by a previously introduced technique that extracts hemoglobin and melanin components by independent component analysis. Experimental results using UV-B irradiation and the application of methyl nicotinate on the arms support the physiological validity of the analysis and the effectiveness of the proposed shading removal. We synthesized the way facial images changed due to tanning or alcohol consumption, and compared the synthesized images with images of actual changes in skin color. The comparison shows an excellent match between the synthesized and actual images of changes due to tanning and alcohol consumption. We also proposed a technique to synthesize the change of texture in pigment due to aging or the application of cosmetics. The pyramid-based texture analysis/synthesis technique was used for the spatial processing of texture. Using the proposed technique, we could realistically change the skin color and texture of a 50 year-old woman to that of a 20 year-old woman.
Light scattering from human hair fibers
Authors: Marschner Stephen R. , Jensen Henrik Wann , Cammarano Mike , Worley Steve , Hanrahan Pat
Published: October 2003

Light scattering from hair is normally simulated in computer graphics using Kajiya and Kay's classic phenomenological model. We have made new measurements of scattering from individual hair fibers that exhibit visually significant effects not predicted by Kajiya and Kay's model. Our measurements go beyond previous hair measurements by examining out-of-plane scattering, and together with this previous work they show a multiple specular highlight and variation in scattering with rotation about the fiber axis. We explain the sources of these effects using a model of a hair fiber as a transparent elliptical cylinder with an absorbing interior and a surface covered with tilted scales. Based on an analytical scattering function for a circular cylinder, we propose a practical shading model for hair that qualitatively matches the scattering behavior shown in the measurements. In a comparison between a photograph and rendered images, we demonstrate the new model's ability to match the appearance of real hair.
iLamps
Authors: Raskar Ramesh , van Baar Jeroen , Beardsley Paul , Willwacher Thomas , Rao Srinivas , Forlines Clifton
Published: October 2003

Projectors are currently undergoing a transformation as they evolve from static output devices to portable, environment-aware, communicating systems. An enhanced projector can determine and respond to the geometry of the display surface, and can be used in an ad-hoc cluster to create a self-configuring display. Information display is such a prevailing part of everyday life that new and more flexible ways to present data are likely to have significant impact. This paper examines geometrical issues for enhanced projectors, relating to customized projection for different shapes of display surface, object augmentation, and co-operation between multiple units.We introduce a new technique for adaptive projection on nonplanar surfaces using conformal texture mapping. We describe object augmentation with a hand-held projector, including interaction techniques. We describe the concept of a display created by an ad-hoc cluster of heterogeneous enhanced projectors, with a new global alignment scheme, and new parametric image transfer methods for quadric surfaces, to make a seamless projection. The work is illustrated by several prototypes and applications.
blue-c
Authors: Gross Markus , Würmlin Stephan , Naef Martin , Lamboray Edouard , Spagno Christian , Kunz Andreas , Koller-Meier Esther , Svoboda Tomas , Van Gool Luc , Lang Silke , Strehlke Kai , Vande Moere Andrew , Staadt Oliver
Published: October 2003

We present
blue-c
, a new immersive projection and 3D video acquisition environment for virtual design and collaboration. It combines simultaneous acquisition of multiple live video streams with advanced 3D projection technology in a CAVE™-like environment, creating the impression of total immersion. The blue-c portal currently consists of three rectangular projection screens that are built from glass panels containing liquid crystal layers. These screens can be switched from a whitish opaque state (for projection) to a transparent state (for acquisition), which allows the video cameras to "look through" the walls. Our projection technology is based on active stereo using two LCD projectors per screen. The projectors are synchronously shuttered along with the screens, the stereo glasses, active illumination devices, and the acquisition hardware. From multiple video streams, we compute a 3D video representation of the user in real time. The resulting video inlays are integrated into a networked virtual environment. Our design is highly scalable, enabling blue-c to connect to portals with less sophisticated hardware.
Untangling cloth
Authors: Baraff David , Witkin Andrew , Kass Michael
Published: October 2003

Deficient cloth-to-cloth collision response is the most serious shortcoming of most cloth simulation systems. Past approaches to cloth-cloth collision have used history to decide whether nearby cloth regions have interpenetrated. The biggest pitfall of history-based methods is that an error anywhere along the way can give rise to persistent tangles. This is a particularly serious issue for production character animation, because characters' bodies routinely self-intersect, for instance in the bend of an elbow or knee, or where the arm or hand rests against the body. Cloth that becomes pinched in these regions is often forced into jagged self-intersections that defeat history-based methods, leaving a tangled mess when the body parts separate. This paper describes a history-free cloth collision response algorithm based on global intersection analysis of cloth meshes at each simulation step. The algorithm resolves tangles that arise during pinching as soon as the surrounding geometry permits, and also resolves tangled initial conditions. The ability to untangle cloth after pinching is not sufficient, because standard cloth-solid collision algorithms handle pinches so poorly that they often give rise to visible flutters and other simulation artifacts during the pinch. As a companion to the global intersection analysis method, we present a cloth-solid collision algorithm called collision flypapering, that eliminates these artifacts. The two algorithms presented have been used together extensively and successfully in a production animation environment.
Precomputing interactive dynamic deformable scenes
Authors: James Doug L. , Fatahalian Kayvon
Published: October 2003

We present an approach for precomputing data-driven models of interactive physically based deformable scenes. The method permits real-time hardware synthesis of nonlinear deformation dynamics, including self-contact and global illumination effects, and supports real-time user interaction. We use data-driven tabulation of the system's deterministic state space dynamics, and model reduction to build efficient low-rank parameterizations of the deformed shapes. To support runtime interaction, we also tabulate
impulse response functions
for a palette of external excitations. Although our approach simulates particular systems under very particular interaction conditions, it has several advantages. First, parameterizing all possible scene deformations enables us to precompute novel reduced coparameterizations of global scene illumination for low-frequency lighting conditions. Second, because the deformation dynamics are precomputed and parameterized as a whole, collisions are resolved within the scene during precomputation so that runtime self-collision handling is implicit. Optionally, the data-driven models can be synthesized on programmable graphics hardware, leaving only the low-dimensional state space dynamics and appearance data models to be computed by the main CPU.
Nonlinear optimization framework for image-based modeling on programmable graphics hardware
Authors: Hillesland Karl E. , Molinov Sergey , Grzeszczuk Radek
Published: October 2003

Graphics hardware is undergoing a change from fixed-function pipelines to more programmable organizations that resemble general purpose stream processors. In this paper, we show that certain general algorithms, not normally associated with computer graphics, can be mapped to such designs. Specifically, we cast nonlinear optimization as a data streaming process that is well matched to modern graphics processors. Our framework is particularly well suited for solving image-based modeling problems since it can be used to represent a large and diverse class of these problems using a common formulation. We successfully apply this approach to two distinct image-based modeling problems: light field mapping approximation and fitting the Lafortune model to spatial bidirectional reflectance distribution functions. Comparing the performance of the graphics hardware implementation to a CPU implementation, we show more than 5-fold improvement.
Behavior of the NORTA method for correlated random vector generation as the dimension increases
Authors: Ghosh Soumyadip , Henderson Shane G.
Published: October 2003

The NORTA method is a fast general-purpose method for generating samples of a random vector with given marginal distributions and given correlation matrix. It is known that there exist marginal distributions and correlation matrices that the NORTA method cannot match, even though a random vector with the prescribed qualities exists. We investigate this problem as the dimension of the random vector increases. Simulation results show that the problem rapidly becomes acute, in the sense that NORTA fails to work with an increasingly large proportion of correlation matrices. Simulation results also show that if one is willing to settle for a correlation matrix that is "close" to the desired one, then NORTA performs well with increasing dimension. As part of our analysis, we develop a method for sampling correlation matrices
uniformly
(in a certain precise sense) from the set of all such matrices. This procedure can be used more generally for sampling uniformly from the space of all symmetric positive definite matrices with diagonal elements fixed at positive values.
A survey of key management for secure group communication
Authors: Rafaeli Sandro , Hutchison David
Published: October 2003

Group communication can benefit from IP multicast to achieve scalable exchange of messages. However, there is a challenge of effectively controlling access to the transmitted data. IP multicast by itself does not provide any mechanisms for preventing nongroup members to have access to the group communication. Although encryption can be used to protect messages exchanged among group members, distributing the cryptographic keys becomes an issue. Researchers have proposed several different approaches to group key management. These approaches can be divided into three main classes: centralized group key management protocols, decentralized architectures and distributed key management protocols. The three classes are described here and an insight given to their features and goals. The area of group key management is then surveyed and proposed solutions are classified according to those characteristics.
ScentTrails
Authors: Olston Christopher , Chi Ed H.
Published: October 2003

The two predominant paradigms for finding information on the Web are browsing and keyword searching. While they exhibit complementary advantages, neither paradigm alone is adequate for complex information goals that lend themselves partially to browsing and partially to searching. To integrate browsing and searching smoothly into a single interface, we introduce a novel approach called ScentTrails. Based on the concept of information scent developed in the context of information foraging theory, ScentTrails highlights hyperlinks to indicate paths to search results. This interface enables users to interpolate smoothly between searching and browsing to locate content matching complex information goals effectively. In a preliminary user study, ScentTrails enabled subjects to find information more quickly than by either searching or browsing alone.
Jam---designing a Java extension with mixins
Authors: Ancona Davide , Lagorio Giovanni , Zucca Elena
Published: October 2003

In this paper we present Jam, an extension of the Java language supporting
mixins
, that is, parametric heir classes. A mixin declaration in Jam is similar to a Java heir class declaration, except that it does not extend a fixed parent class, but simply specifies the set of fields and methods a generic parent should provide. In this way, the same mixin can be instantiated on many parent classes, producing different heirs, thus avoiding code duplication and largely improving modularity and reuse. Moreover, as happens for classes and interfaces, mixin names are reference types, and all the classes obtained by instantiating the same mixin are considered subtypes of the corresponding type, and hence can be handled in a uniform way through the common interface. This possibility allows a programming style where different ingredients are "mixed" together in defining a class; this paradigm is somewhat similar to that based on multiple inheritance, but avoids its complication.The language has been designed with the main objective in mind to obtain, rather than a new theoretical language, a working and smooth extension of Java. That means, on the design side, that we have faced the challenging problem of integrating the Java overall principles and complex type system with this new notion; on the implementation side, it means that we have developed a Jam-to-Java translator which makes Jam sources executable on every Java Virtual Machine.
Measuring praise and criticism
Authors: Turney Peter D. , Littman Michael L.
Published: October 2003

The evaluative character of a word is called its
semantic orientation
. Positive semantic orientation indicates praise (e.g., "honest", "intrepid") and negative semantic orientation indicates criticism (e.g., "disturbing", "superfluous"). Semantic orientation varies in both direction (positive or negative) and degree (mild to strong). An automated system for measuring semantic orientation would have application in text classification, text filtering, tracking opinions in online discussions, analysis of survey responses, and automated chat systems (
chatbots
). This article introduces a method for inferring the semantic orientation of a word from its statistical association with a set of positive and negative paradigm words. Two instances of this approach are evaluated, based on two different statistical measures of word association: pointwise mutual information (PMI) and latent semantic analysis (LSA). The method is experimentally tested with 3,596 words (including adjectives, adverbs, nouns, and verbs) that have been manually labeled
positive
(1,614 words) and
negative
(1,982 words). The method attains an accuracy of 82.8% on the full test set, but the accuracy rises above 95% when the algorithm is allowed to abstain from classifying mild words.
Coverage, relevance, and ranking
Authors: Eastman Caroline M. , Jansen Bernard J.
Published: October 2003

Research has reported that about 10% of Web searchers utilize advanced query operators, with the other 90% using extremely simple queries. It is often assumed that the use of query operators, such as Boolean operators and phrase searching, improves the effectiveness of Web searching. We test this assumption by examining the effects of query operators on the performance of three major Web search engines. We selected one hundred queries from the transaction log of a Web search service. Each of these original queries contained query operators such as AND, OR, MUST APPEAR (+), or PHRASE (" "). We then removed the operators from these one hundred advanced queries. We submitted both the original and modified queries to three major Web search engines; a total of 600 queries were submitted and 5,748 documents evaluated. We compared the results from the original queries with the operators to the results from the modified queries without the operators. We examined the results for changes in coverage, relative precision, and ranking of relevant documents. The use of most query operators had no significant effect on coverage, relative precision, or ranking, although the effect varied depending on the search engine. We discuss implications for the effectiveness of searching techniques as currently taught, for future information retrieval system design, and for future research.
A semisupervised learning method to merge search engine results
Authors: Si Luo , Callan Jamie
Published: October 2003

The proliferation of searchable text databases on local area networks and the Internet causes the problem of finding information that may be distributed among many disjoint text databases (
distributed information retrieval
). How to merge the results returned by selected databases is an important subproblem of the distributed information retrieval task. Previous research assumed that either resource providers cooperate to provide normalizing statistics or search clients download all retrieved documents and compute normalized scores without cooperation from resource providers.This article presents a semisupervised learning solution to the result merging problem. The key contribution is the observation that information used to create resource descriptions for resource selection can also be used to create a centralized sample database to guide the normalization of document scores returned by different databases. At retrieval time, the query is sent to the selected databases, which return database-specific document scores, and to a
centralized sample database
, which returns database-independent document scores. Documents that have both a database-specific score and a database-independent score serve as training data for learning to normalize the scores of other documents. An extensive set of experiments demonstrates that this method is more effective than the well-known CORI result-merging algorithm under a variety of conditions.
A multiple bit upset tolerant SRAM memory
Authors: Neuberger Gustavo , de Lima Fernanda , Carro Luigi , Reis Ricardo
Published: October 2003

SRAMs are used nowadays in almost every electronic product. However, as technology shrinks transistor sizes, single and multiple bit upsets only observable in space applications previously are now reported at ground level. This article presents a high level technique to protect SRAM memories against multiple upsets based on correcting codes. The proposed technique combines Reed Solomon code and Hamming code to assure reliability in presence of multiple bit flips with reduced area and performance penalties. Multiple upsets were randomly injected in various combinations of memory cells to evaluate the robustness of the method. The experiment was emulated in a Virtex FPGA platform. Results show that 100% of the injected double faults and a large amount of multiple faults were corrected by the method.
Evaluating modeling techniques based on models of learning
Authors: Gemino Andrew , Wand Yair
Published: October 2003

To compare modeling techniques, combine grammar-based and cognitive-based approaches and test domain understanding.
Using ontology to validate conceptual models
Authors: Shanks Graeme , Tansley Elizabeth , Weber Ron
Published: October 2003

Theories of ontology lead to improved conceptual models and help ensure they are indeed faithful representations of their focal domains.
Continuous random variate generation by fast numerical inversion
Authors: Hörmann Wolfgang , Leydold Josef
Published: October 2003

The inversion method for generating nonuniform random variates has some advantages compared to other generation methods, since it monotonically transforms uniform random numbers into non-uniform random variates. Hence, it is the method of choice in the simulation literature. However, except for some simple cases where the inverse of the cumulative distribution function is a simple function we need numerical methods. Often inversion by "brute force" is used, applying either very slow iterative methods or linear interpolation of the CDF and huge tables. But then the user has to accept unnecessarily large errors or excessive memory requirements, that slow down the algorithm. In this article, we demonstrate that with Hermite interpolation of the inverse CDF we can obtain very small error bounds close to machine precision. Using our adaptive interval splitting method, this accuracy is reached with moderately sized tables that allow for a fast and simple generation procedure.
Neural mechanisms of sexual imprinting
Authors: Bischof Hans-Joachim
Published: October 2003

Sexual imprinting is an early learning process by which a young animal acquires information which will help in choosing a sexual partner. It consists of two separate phases, an acquisition phase where features of the social environment are learnt, and a stabilisation phase in which, guided by the previously acquired social information, a preference for a sexual partner is established and stabilised, such that it cannot be altered subsequently. The stabilisation process is short and can be controlled experimentally. This review summarises research on the neural events accompanying consolidation in those brain areas which have previously been identified as important for imprinting. It shows that the period during which consolidation can occur can be shifted only within a certain time window, and demonstrates the fast adjustment of spine densities within the imprinting areas after consolidation has started. It further suggests that long term potentiation (LTP) and long term depression (LTD)-like mechanisms may be involved in this learning process, and that the immediate early genes ZENK and c-fos are expressed within the relevant imprinting areas in the course of consolidation. Evidence is presented for a prominent role of the lateral neostriatum in the imprinting process, and also for the involvement of the hippocampus in this type of early learning.
Innovation and social learning: individual variation and brain evolution
Authors: Reader Simon
Published: October 2003

This paper reviews behavioural, neurological and cognitive correlates of innovation at the individual, population and species level, focusing on birds and primates. Innovation, new or modified learned behaviour not previously found in the population, is the first stage in many instances of cultural transmission and may play an important role in the lives of animals with generalist or opportunistic lifestyles. Within-species, innovation is associated with low neophobia, high neophilia, and with high social learning propensities. Indices of innovatory propensities can be calculated for taxonomic groups by counting the frequency of reports of innovation in published literature. These innovation rate data provide a useful comparative measure for studies of behavioural flexibility and cognition. Innovation rate is positively correlated with the relative size of association areas in the brain, namely the hyperstriatum ventrale and neostriatum in birds, and the neocortex and striatum in primates. Innovation rate is also positively correlated with the reported variety of tool use, as well as interspecific differences in learning. Current evidence thus suggests similar patterns of cognitive evolution in primates and birds.
Everyday Race-Making
Authors: Lewis Amanda E.
Published: October 2003

Sociologists working in the racial formation tradition have made a clear case for under-standing race as a political and social construction and have detailed macroprocesses of production. However, we still do not understand enough about how race is reproduced through microlevel interactions. Drawing on ethnographic data from research in schools, the author examines everyday race-making—the processes through which race and racial categories are reproduced and contested in daily life. As racial identities are assigned to individuals and racial categories are mapped onto groups, these groups and individuals are simultaneously included in or excluded from a variety of social interactions and social institutions. It is through these everyday interactions that racial boundaries are formed and renegotiated.
Race and Hegemony
Authors: Arena John
Published: October 2003

A central locus of social scientific research throughout the past two decades has been the reorganization of capitalist control within various institutions and societies in the post-Fordist era. This study examines the process within the context of a majority Black city in the United States. Drawing on the theory of hegemony and the Black urban regime, the author examines the mix of consensual and authoritarian practices the regime employs to impose the neoliberal agenda. Findings suggest that regime elites, in lieu of any real material con-cessions, are increasingly relying on authoritarian and ideological forms of control.
The Heart of the Politics of Race
Authors: Harris-Lacewell Melissa V.
Published: October 2003

This piece confronts a serious deficiency in the literature on racial politics. The defining works of White racial attitudes fail to grapple with the complexities of African American political thought and life. In these studies, Black people are a static object about which White people form opinions. This article offers a critique of the field of race politics by outlining the con-sequences of a failure to seriously include African Americans in theoretical and empirical analyses of American race.
Changing Racial Attitudes in Zimbabwe
Authors: Kinloch Graham C.
Published: October 2003

This article focuses on racial attitudes in post-colonial Zimbabwe as revealed in letters to the editor, published in one of the country's weekly newspapers from the late 1980s through the 1990s. These data revealed that African authors were the consistent majority during this period and focused on their institutional needs, becoming increasingly critical of their government. White authors, on the other hand, remained the minority and emphasized the maintenance of institutional standards and efficiency, remaining consistently skeptical of the country's Black government. The analysis concludes by addressing the theoretical and policy implications of these results.
Ragaglitazar: The Pharmacokinetics, Pharmacodynamics, and Tolerability of a Novel Dual PPARα and γ Agonist in Healthy Subjects and Patients with Type 2 Diabetes
Authors: Skrumsager B. K. , Nielsen K. K. , Müller M. , Pabst G. , Drake P. G. , Edsberg B.
Published: October 2003

Ragaglitazar is a novel dual peroxisome proliferator‐activated receptor (PPAR) α and γ agonist intended to restore insulin sensitivity and correct diabetic dyslipidemia. These studies assessed single‐dose pharmacokinetics and tolerability of ragaglitazar in healthy subjects, as well as multiple‐dose pharmacokinetics, pharmacodynamics, and tolerability of ragaglitazar in healthy subjects and in patients with type 2 diabetes. Healthy subjects received a single oral dose (1–120 mg), and healthy subjects and type 2 diabetic patients received a loading dose and thereafter once‐daily doses (0.5–16 mg) of ragaglitazar for 6 and 20 days, respectively. Ragaglitazar was rapidly absorbed (tmax: 1.5–1.7 h), with mean AUC0–24 h and Cmax proportional to dose after single and multiple dosing; t1/2 was 80 hours following a single dose and 104 hours in healthy subjects and 122 hours in patients after multiple dosing. Administration of 4 mg ragaglitazar to patients (n = 4) for 21 days resulted in mean decreases from baseline in fasting levels of plasma glucose (18%), C‐peptide (18%), fructosamine (6%), triglycerides (36%), free fatty acids (49%), total cholesterol (11%), low‐density lipoprotein (LDL) cholesterol (21%), and very low‐density lipoprotein (VLDL) cholesterol (15%), as well as an increase in high‐density lipoprotein (HDL) cholesterol (33%). Overall, ragaglitazar was well tolerated; with multiple dosing, there was a higher incidence of adverse events for patients that, at the highest dose level (16 mg), included peripheral edema and anemia.
CYP2C19‐ and CYP3A4‐Dependent Omeprazole Metabolism in West Mexicans
Authors: Gonzalez Héctor M. , Romero Elba M.T. , Peregrina A.L. Aaron , Chávez Teresa de J.C. , Escobar‐Islas Estanislao , Felipe Lozano K. , Hoyo‐Vadillo Carlos
Published: October 2003

Omeprazole has been used as a drug probe for CYP2C19, but no systematic data are available for Mexican populations. The aim of this study was to evaluate the phenotype frequencies of the CYP2C19 polymorphism in West Mexicans. Besides omeprazole, sulfone was measured to evaluate CYP3A4 after administration of the 20‐mg dose to 127 healthy volunteers. Logarithms of metabolic indexes of omeprazole/hydroxyomeprazole for CYP2C19 and omeprazole/omeprazole sulfone for CYP3A4 had trimodal distributions. Five subjects (4%) had a log CYP2C19 metabolic index below −0.9, suggesting an ultra‐extensive phenotype. Poor metabolizers (log metabolic index > 0.6) were 6%. For CYP3A4, 11 subjects (9%) were below −0.3 of the log metabolic index. The log metabolic index of omeprazole/omeprazole sulfone was above the antimode of 0.6 for 11% of this population. The mean log metabolic index of CYP3A4 extensive metabolizers (80%) was 0.166, which seems to be higher than the data described for Caucasians and lower than that for Asians.
Pharmacokinetic and Pharmacodynamic Interactions of Oral Midazolam with Ketoconazole, Fluoxetine, Fluvoxamine, and Nefazodone
Authors: Lam Y. W. Francis , Alfaro Cara L. , Ereshefsky Larry , Miller Michael
Published: October 2003

The objective of this study was to investigate pharmacokinetic and pharmacodynamic interactions between midazolam and fluoxetine, fluvoxamine, nefazodone, and ketoconazole. Forty healthy subjects were randomized to receive one of the four study drugs for 12 days in a parallel study design: fluoxetine 60 mg per day for 5 days, followed by 20 mg per day for 7 days; fluvoxamine titrated to a daily dose of 200 mg; nefazodone titrated to a daily dose of 400 mg; or ketoconazole 200 mg per day. All 40 subjects received oral midazolam solution before and after the 12‐day study drug regimen. Blood samples for determination of midazolam concentrations were drawn for 24 hours after each midazolam dose and used for the calculation of pharmacokinetic parameters. The effects of the study drugs on midazolam pharmacodynamics were assessed using the symbol digit modalities test (SDMT). The mean area under the curve (AUC) for midazolam was increased 771.9% by ketoconazole and 444.0% by nefazodone administration. However, there was no significant change in midazolam AUC as a result of fluoxetine (13.4% decrease) and a statistical trend for fluvoxamine (66.1% increase) administration. Pharmacodynamic data are consistent with pharmacokinetic data indicating that nefazodone and ketoconazole resulted in significant increases in midazolam‐related cognition impairment. The significant impairment in subjects' cognitive function reflects the changes in midazolam clearance after treatment with ketoconazole and nefazodone. These results suggest that caution with the use of midazolam is warranted with potent CYP3A4 inhibitors.
Assessment of Marijuana Use and Psychosocial Behaviors at Two Historically Black Universities
Authors: Bowen-Reid Terra L. , Rhodes Warren A.
Published: October 2003

Research exploring marijuana use patterns in students at historically Black colleges and universities (HBCUs)is relatively sparse. This study sought to empirically assess three constructs (resilient, invulnerable, and vulnerable)as they relate to marijuana use and to assess the role of spirituality and social support as potential buffering mechanisms. Participants in this study were 1,013 African American undergraduate students from two HBCUs in the mid-Atlantic region of the United States. Participants completed a 95-item survey assessing demographic and behavioral patterns of college students. The findings provide preliminary support for quantitative distinctions between marijuana risk categories based on the selected risk and protective factors. In particular, respondents who continue to use marijuana (vulnerables)were less spiritual compared to those who either halted use (resilients) or those who never used marijuana at all (invulnerables). Implications are discussed in terms of theory-building and prevention strategies.
Subjective Stress and Coping Resources Interact to Predict Blood Pressure Reactivity in Black College Students
Authors: Clark Rodney
Published: October 2003

This study examined the effects of subjective stress and coping resources on blood pressure reactivity. Sixty-nine Black college students (mean age = 23.58 years) completed the Life Experiences and Stress Scale to explore the subjective stressfulness associated with life events, the Coping Orientations to Problems Experienced Scale to measure usual ways of coping, and a standardized serial addition laboratory challenge during which blood pressure was assessed. Multiple regression analyses revealed that the interactive effects of subjective stress and coping resources predicted diastolic blood pressure reactivity (both p < .025) but not systolic blood pressure reactivity (both p > .10). These significant interaction effects indicated that higher levels of problem-focused coping were related to more marked diastolic blood pressure changes under conditions of high subjective stress and that emotion-focused coping was associated with less exaggerated diastolic blood pressure changes under conditions of low subjective stress. These findings highlight the potential contribution of psychosocial factors to blood pressure reactivity in Blacks.
“Clean your Room!”
Authors: Smetana Judith G. , Daddis Christopher , Chuang Susan S.
Published: October 2003

Middle-class African American adolescents' and parents' (n = 82 families) everyday conflicts were examined longitudinally over 2 years. The number and frequency of conflicts did not change from early to middle adolescence, but mothers rated conflicts as less intense and adolescents rated conflicts as more intense over time. Conflicts over home-work increased and conflicts over the adolescents' rooms declined from early to middle adolescence. African American adolescents primarily justified conflicts on the basis of personal jurisdiction, and personal reasoning increased significantly with age. Mothers' pragmatic justifications for conflicts increased and their social-conventional justifications decreased over time. Across ages, nearly all conflicts were resolved by adolescents' giving in to parents. Compromise was relatively infrequent but increased with age, whereas reported use of punishment decreased. Although conflict may reflect normative developmental processes of individuation, the cultural and ecological context of middle-class African American families influences its expression and resolution.
Adolescent Dating Violence Victimization and Psychological Well-Being
Authors: Callahan Michelle R. , Tolman Richard M. , Saunders Daniel G.
Published: October 2003

This study assesses the relationship between adolescents' dating violence victimization and their psychological well-being. The participants were 190high school students, ages 13 to 19 years, with just over half being boys (53%) and the remainder being girls (47%). Data were collected using self-administered questionnaires. For girls, increasing levels of dating violence (severity, frequency, injury) were related to higher levels of post-traumatic stress and dissociation, even after controlling for demographic, family violence, and social desirability variables. For boys, the levels of victimization were related to higher levels of anxiety, depression, and posttraumatic stress, even after controlling for other variables. For both boys and girls, victimization was related to lower levels of life satisfaction, but not after controlling for the demographic, family violence, and social desirability variables. The research questions and findings are discussed in relation to the developmental challenges faced by adolescents.
From Gut Knowing: Every Silver Cloud has a Black Lining
Authors: Elmes Michael
Published: October 2003

Using the interpretive lens of Erving Goffman’s Presentation of Self in Everyday Life , this article makes sense of the performance of Steve Taylor’s play, “Ties That Bind”, from the perspective of the actors, 14 faculty members, and doctoral students from various universities in the United States. The article is based not only on actor reflections on their experiences as participants in the play but also on the author’s interpretation of these reflections and his observations of what transpired on the frontstage and backstage of the performance. Every actor experienced his or her participation in the play as energizing, liberating, and fun. Yet, paradoxically, although the play dissected and exposed the perils of academic roles and face, their subtle reproduction during rehearsals, between takes, and at lunch, that is, on the backstage of the performance, was initially a surprise to the author—and a cause for inquiry.
The Need for Government-Wide Information Capacity
Authors: Mullen Patrick R.
Published: October 2003

Jane Fountain discussed the need for government-wide or federal interagency information capacity. She concluded that the constraints of the Clinger-Cohen Act's reporting mechanisms have caused the U.S. General Accounting Office (GAO) to lose sight of the big picture—the need for interagency net-working and information technology (IT) oversight. However, there has been considerable behind-the-scenes work by GAO to bring about passage of legislation to increase government-wide information capacity through, for example, the E-Government Act of 2002. The act establishes (a) an Office of Electronic Government within the Office of Management and Budget and (b) data sharing between certain agencies. Much of GAO's work tends not to be reflected in reports on individual agency IT problems. However, GAO has testified of the need for more government-wide focus on IT challenges, lending support to Dr. Fountain's overall point about the need for government-wide information capacity.
“Shadow Theories” in Fountain's Theory of Technology Enactment
Authors: Grafton Carl
Published: October 2003

Fountain was concerned with the effect of information technologies on government. Her thesis was that government organizations are strongly motivated to adopt information technologies and that the ways these technologies are used and their effects vary depending on agency interests. Although Fountain claimed to present original ideas, elements of her thesis have been commonplace for decades in political science, public administration, business administration, and the field of science, technology, and public policy. Instead of crediting orthodox concepts such as technological determinism, rational actor models, incrementalism, and systems analysis, she attacked them as “shadow theories” only to import large elements of them back into her own framework. Fountain sought to dazzle us with her originality when she really was assembling a worthwhile research agenda out of good ideas taken from existing scholarship. Instead of encouraging cooperation in her modest venture, she invites a backlash.
Building the Virtual State... or Not?
Authors: Norris Donald F.
Published: October 2003

In this article, the author advances four arguments about Building the Virtual State. First, it is a historical and fails to take into account the rich and rewarding literature about information technology (IT) and government developed over the past 3 decades. Second, its theory of IT enactment is little more than a repackaging of the dominant extant theory in the field, sociotechnical systems theory. Third, evidence provided from the three case studies in the book is insufficient to test enactment (or any other) theory of IT and government. Finally, although the book claims to be about the virtual state, only one of the case studies addresses the movement of government services onto the Internet (the author's definition of the virtual state), and the other two cases do not address it at all. For these reasons, Building the Virtual State is a disappointment, and it delivers a good bit less than it promises.