bluuebunny/crossref_metadata_2025 huggingface dataset:
Rolling Manipulation with a Single Control
Authors: Choudhury Prasun , Lynch Kevin M.
Published: June 2003

Underactuated manipulation is the process of controlling several object degrees-of-freedom with fewer robot actuators. Underactuated manipulation allows us to build dexterous robots with only a few actuators. In this paper we explore the possibility of useful dynamic manipulation with only a single actuator. Our case study is a ball rolling in an asymmetrical bowl which can be accelerated along one linear degree-of-freedom. We show that the state of the ball relative to the bowl is controllable by this single controlled acceleration. In particular, it is possible to control the equilibrium orientation of the ball on the three-dimensional manifold SO(3 ) using this single input. We have built an experimental demonstration of this system and we have constructed a motion planner to find a sequence of motions of the bowl to accomplish a desired reorientation.
Design and Control of a Chained Form Manipulator
Authors: Chung Woojin , Nakamura Yoshihiko
Published: June 2003

Exploiting unique features of nonholonomic systems, innovative and advantageous mechanisms can be designed. We have proposed a nonholonomic manipulator which is a controllable n joint manipulator with only two actuators. In order to create its nonholonomic constraint, a special type of velocity transmission, called the non-holonomic gear, was developed.

There are many possible alternatives for designing underactuated manipulators using the nonholonomic gear. In this paper, the chained form manipulator is designed not only to satisfy chained form convertibility, but also to achieve control simplicity. Design requirements are clarified, then we establish the mechanical design of the chained form manipulator. The chained form manipulator is designed with an innovative main power train as well as nonholonomic gears. For experimental verification, a prototype is fabricated.

So far, various control strategies for nonholonomic systems have been proposed. In this paper, an efficient motion planning scheme for the chained form is presented to approximate any holonomic path with the feasible nonholonomic path. Furthermore, a new concept of motion planning is proposed through the analysis of the initial-condition sensitivity. Combining these two approaches, the motion planning scheme is constructed towards practical applications. Presented experimental results show the usefulness of the design and the applied control scheme.
On Fitted Stratified and Semi-Stratified Geometric Manipulation Planning with Fingertip Relocations
Authors: Harmati István , Lantos Béla , Payandeh Shahram
Published: June 2003

This paper presents two object manipulation planning methods based on fitted stratified and semi-stratified approaches using finger relocations. The problem is discussed in the framework of a motion planning problem. The goal of the methods is to steer an object from an initial configuration to a final configuration while it is possible to reposition the fingertips on the surface in a predefined way. We assume there is no rolling and sliding but finger relocations are allowed. The first technique follows a pure stratified approach, however unlike the previously published method, the exact kinematic model of the manipulation system is matched with a virtual model masking the behavior of the original system. This provides a simpler model than the earlier stratified method by reducing the generally hard symbolic computation problem to a simple (almost pure numerical) one. The paper also introduces a semi-stratified manipulation planning based on the newly defined fitted system. This second method enhances the stratified motion planning with a definition of systematic finger relocation sequence. The proposed decomposition is based on the selection of suitable reference contact points. As the main benefit, the method enables a greater freedom in defining the desired fingertip trajectories. The methods are illustrated through an example of object reorientation.
Development of a Fault-Tolerant Omnidirectional Wheeled Mobile Robot Using Nonholonomic Constraints
Authors: Jung Myung-Iin , Kim Jong-Hwan
Published: June 2003

Robots used in hazardous environments need a high degree of mobility with good precision and robustness to actuator failures. In this paper, a novel gear train is proposed to satisfy the requirement for such a mechanism. The gear train is developed based on the following principles: (i) the mechanism is omnidirectional for a high degree of mobility, (ii) the mechanism uses only conventional tirewheels for high precision, and (iii) the mechanism uses only three motors for no actuation redundancy; at the same time, it has robustness to actuator failure so that when any one of the motors is not functioning properly, regardless of which one is not and regardless of the configuration at the moment of failure, the posture is controllable with the other two working actuators. By virtue of the proposed gear train, in an actuator failure, the entire structure becomes similar to a differentially driven two-wheeled mobile robot subject to nonholonomic constraints. The nonholonomic constraints, inherent in the mechanism and stemming from an actuator failure, are crucial to maintain the controllability of the robot posture when omnidirectional mobility is lost due to actuator failure. Controllability is proved and control laws are presented for both the omnidirectional mode, when all three motors are functioning, and the non-omnidirectional mode, when one of the motors is locked due to a failure. The omnidirectional mobility and robustness to an actuator failure is verified by experimental results.
Control of Micro-Satellite Orientation Using Bounded-Input, Fully-Reversed MEMS Actuators
Authors: Sung Key Koh  , Ostrowski James P. , Ananthasuresh G.K.
Published: June 2003

We present a novel technique for controlling the attitude of micro-satellites using MEMS-based microactuators. In addition to being restricted in the magnitudes of inputs, most microactuators need to be returned to their original inactive state at the end of the attitude control maneuver in order to reduce energy consumption. This type of bounded and fully-reversed actuation on a free rigid body leads to a special type of system in which nonholonomic effects have been incorporated by design . We discuss issues of controllability and develop motion planning algorithms for such a system considering the nonintegrable nature of rigid body rotations. We use approximate methods to develop two algorithms for controlling satellite orientation. The first method uses a series of pair-wise actuation steps and is guaranteed to converge to the desired orientation; the second uses fewer steps, and in certain cases uses less input power. We also present preliminary results of a practical implementation using electro-thermal microactuation.
Translational and Rotational Maneuvers of an Underactuated Space Robot using Prismatic Actuators
Authors: Jinglai Shen  , McClamroch N. Harris
Published: June 2003

We study the simultaneous control of three dimensional translation and rotation of an underactuated multibody space robot using sliding masses that are configured as ideal prismatic actuators. A crucial assumption is that the total linear and angular momenta of the space robot are zero. The prismatic actuators may be intentional actuation devices or they may be dual-use devices such as retractable booms, tethers, or antennas that can also serve as space robot actuation devices. The paper focuses on the underactuation case, i.e., the space robot has three independent prismatic actuators, which are used to control the six base body degrees of freedom. Controllability results are developed, revealing controllability properties for the base body translation, base body attitude, and actuator displacement. Based on the controllability results, an algorithm for rest-to-rest base body maneuvers is constructed using a Lie bracket expansion. An example of a three dimensional space robot maneuver is presented. The results in the paper demonstrate the importance of “nonholonomy” and related nonlinear control approaches for space robots that satisfy the prismatic actuation assumptions.
Rolling Based Manipulation under Neighborhood Equilibrium
Authors: Harada Kensuke , Kawashima Taiga , Kaneko Makoto
Published: June 2003

This paper proposes an idea of Neighborhood Equilibrium (NE) and applies it to the manipulation of an object. Under NE, an object with rolling contact can automatically find another equilibrium state close to the original one even when the current one is broken due to the change of input. For manipulating an object by taking NE into account, all the contact coordinates between the object and the plate are controlled to the desired values. To guarantee NE during the manipulation, we define the contact stable region (CSR) on the object surface. We plan the trajectory of contact coordinates within the CSR. The planned trajectory of contact point on the object surface is composed of multiple equilateral triangles. By using the Gauss-Bonnet theorem, the reachability of the algorithm is shown for a spheroidal object. Numerical examples and experiments are shown to explain our idea.
Visual Servoing from Lines
Authors: Andreff Nicolas , Espiau Bernard , Horaud Radu
Published: June 2003

In this paper, we present a new approach to visual servoing using lines. It is based on a theoretical and geometrical study of the main line representations, which allows us to define a new representation, the so-called binormalized Plücker coordinates. These are particularly well suited for visual servoing. Indeed, they allow the definition of an image line alignment concept. Moreover, the control law which realizes such an alignment has several properties: partial decoupling between rotation and translation, analytical inversion of the motion equations and global asymptotic stability conditions. This control law was validated both in simulation and experimentally in the specific case of an orthogonal trihedron.
An Experimental Robot Load Identification Method for Industrial Application
Authors: Swevers J. , Verdonck W. , Naumer B. , Pieters S. , Biber E.
Published: June 2003

In this paper, we discuss a new experimental robot load identification method that is used in industry. The method is based on periodic robot excitation and the maximum likelihood estimation of the parameters, techniques adopted from Swevers et al. (1997 IEEE Transactions on Robotics and Automation 13(5):730—740). This method provides: (1) accurate estimates of the robot load inertial parameters; and (2) accurate actuator torque predictions. These are both essential for the acceptance of the results in an industrial environment. The key element to the success of this method is the comprehensiveness of the applied model, which includes, besides the dynamics resulting from the robot load and motor inertia, the coupling between the actuator torques, the mechanical losses in the motors and the efficiency of the transmissions. Accurate estimates of the robot link and motor inertial parameters, which can be considered identical for all robots of the same type, are obtained from separate experiments (see Swevers et al.), and used as a priori knowledge for the robot load identification. We present experimental results on a KUKA industrial robot equipped with a calibrated test load.
Mobile Robot Localization and Mapping with Uncertainty using Scale-Invariant Visual Landmarks
Authors: Se Stephen , Lowe David , Little Jim
Published: June 2003

A key component of a mobile robot system is the ability to localize itself accurately and, simultaneously, to build a map of the environment. Most of the existing algorithms are based on laser range finders, sonar sensors or artificial landmarks. In this paper, we describe a vision-based mobile robot localization and mapping algorithm, which uses scale-invariant image features as natural landmarks in unmodified environments. The invariance of these features to image translation, scaling and rotation makes them suitable landmarks for mobile robot localization and map building. With our Triclops stereo vision system, these landmarks are localized and robot ego-motion is estimated by least-squares minimization of the matched landmarks. Feature viewpoint variation and occlusion are taken into account by maintaining a view direction for each landmark. Experiments show that these visual landmarks are robustly matched, robot pose is estimated and a consistent three-dimensional map is built. As image features are not noise-free, we carry out error analysis for the landmark positions and the robot pose. We use Kalman filters to track these landmarks in a dynamic environment, resulting in a database map with landmark positional uncertainty.
The Effect of Transcutaneous Electrical Nerve Stimulation on Spasticity in Multiple Sclerosis Patients: A Pilot Study
Authors: Armutlu Kadriye , Meriç Aydin , Kirdi Nuray , Yakut Edibe , Karabudak Rana
Published: June 2003

The aim of this study was to examine the effects of transcutaneous electrical nerve stimulation on spasticity in patients with multiple sclerosis. The study was carried out in the Hacettepe University School of Physical Therapy and Rehabilitation. The subjects in the study were 10 clinically definite, primary and secondary progressive type multiple sclerosis outpatients with mild to moderate spasticity in the plantar flexor muscles of the ankle. Stimuli of frequency 100 Hz and pulse width 0.3 msec were used 20 minutes per day for 4 weeks. Patients were assessed by electromyography, Modified Ashworth Scale, and Ambulation Index. Electromyography was performed before and after the daily treatment of spastic muscles with transcutaneous electrical nerve stimulation in order to assess the effect on muscle relaxation. The Modified Ashworth Scale and Ambulation Index were used before and after 4 weeks' treatment. After 4 weeks of treatment, there were statistically significant reductions in spasticity of both extremities as assessed by myoelectric activity and the Modified Ashworth Scale (P < 0.05). Ambulation Index level was not improved significantly)P > 0.05).
Assessing Mobility and Locomotor Coordination after Stroke with the Rise-to-Walk Task
Authors: Dion Lise , Malouin Francine , McFadyen Bradford , Richards Carol L.
Published: June 2003

Introduction. To assess mobility and locomotor coordination after stroke with the rise-to-walk task (RTW) and to examine the construct and concurrent validity of this task. Methods. Nineteen subjects who had sustained a stroke and 19 healthy subjects performed the RTW task. The performance was recorded simultaneously with 2 clinical methods and 1 instrumented method. The RTW duration and fluidity of the motor strategy (fluid or non-fluid) were compared between groups and between methods. The relationship between RTW duration and 3 locomotor-related disability tests, as well as 1 motor impairment test, was studied. Results. The subjects with stroke took 65% more time to complete the RTW task, and 16/19 separated the tasks of rising and walking (nonfluid strategy). Measures of the RTW duration with clinical methods were strongly correlated (r = 0.84 to 0.98) to those from the instrumented method, and the motor strategy was successfully assessed from video records. The duration was moderately correlated to scores from other locomotor-related tests, but not to the motor impairment test. Discussion. The assessment of mobility and locomotor coordination with the RTW task indicate that both outcomes are impaired after stroke and that clinical methods provide a valid measurement of the task.
Effects of Practice and Unpredictable Distractors on Planning and Executing Aiming after Stroke
Authors: Pohl Patricia S. , Filion Diane L. , Kim Seok Hun
Published: June 2003

The primary purpose of this study was to examine practice effects on the planning and execution of an aiming movement after right versus left stroke. A secondary purpose was to investigate the effects of a distractor that appeared randomly on motor performance after stroke. Right-hand dominant individuals, 15 with right stroke (right-sided brain damage), 16 with left stroke, and 30 without stroke, performed aiming movements to targets. Those with stroke used the ipsilesional upper extremity (UE). Right and left comparison groups used the right and left UE, respectively. Reaction time (RT) and movement time (MT) were collected to represent movement planning and execution, respectively. Individuals with right stroke improved RT with practice. Individuals with left stroke did not improve RT with practice and made more errors than their comparison group. Those with left stroke achieved faster MT with practice, but MT remained slower than their comparison group. There were no effects of the distractor on RT or MT. Adults with left stroke have persistent deficits in movement planning and execution. Further studies are needed to determine how the performance of older adults, with or without stroke, is affected by an unpredictable visual distractor.
Effects of Low-Frequency Cranial Electrostimulation on the Rest-Activity Rhythm and Salivary Cortisol in Alzheimer's Disease
Authors: Scherder Erik , Knol Dirk , van Someren Eus , Deijen Jan-Berend , Binnekade Rob , Tilders Fred , Sergeant Joseph
Published: June 2003

Objective. In previous studies, cranial electrostimulation (CES) had positive effects on sleep in depressed patients and in patients with vascular dementia. The present study examined the effects of low-frequency CES on the rest-activity rhythm and cortisol levels of patients with probable Alzheimer's disease (AD). Method. It was hypothesised that a decreased level of cortisol would parallel a positive effect of low-frequency CES on nocturnal restlessness. Sixteen AD patients were randomly assigned to an experimental group (n = 8) or a control group (n = 8). The experimental group was treated with CES, whereas the control group received sham stimulation, for 30 minutes a day, during 6 weeks. The rest-activity rhythm was assessed by actigraphy. Cortisol was measured repeatedly in the saliva throughout the day by means of salivette tubes. Results. Low-frequency CES did not improve the rest-activity rhythm in AD patients. Moreover, both groups showed an increase instead of a decrease in the level of cortisol. Conclusions: These preliminary results suggest that low-frequency CES has no positive effect on the rest-activity rhythm in AD patients. An alternative research design with high-frequency CES in AD is discussed.
Intramuscular Hand Neuroprosthesis for Chronic Stroke Survivors
Authors: Chae John , Hart Ronald
Published: June 2003

The purpose of this study was to assess the feasibility of a percutaneous band neuroprosthesis system for stroke survivors. Case reports of 4 chronic stroke survivors who were implanted with percutaneous intramuscular electrodes in various muscles of the forearm for hand grasp and release are presented. A percutaneous hand neuroprosthesis was able to open a spastic hemiparetic hand as long as the upper limb was in a resting position, the wrist and proximal forearm were supported, participants did not try to assist the stimulation, and an individual other than the participant modulated the stimulation. However, when participants tried to assist the stimulation or complete a functional task, hand opening was significantly reduced due to increased finger flexor hypertonia, even with increased stimulation intensity. Similarly, electrically stimulated hand opening was significantly reduced following voluntary hand closure. Techniques that provide real-time modulation of hypertonia with closed loop control, control strategies that are independent of the contralateral limb, and methods to enhance proximal control must be developed to demonstrate the feasibility of a hand neuroprosthesis system for persons with hemiparesis.
The Impact of Ulnar Nerve Compression at the Elbow on the Hand Function of Heavy Manual Workers
Authors: Amirjani Nasim , Thompson Shelley , Satkunam Lalith , Lobay Gary L. W. , Chan K. Ming
Published: June 2003

The objectives of this article were to study the impact of the hand function disability due to ulnar neuropathy at the elbow (UNE) on workers engaged in occupations requiring heavy hand use. Four patients (42.5 ± 7 years old), all engaged in heavy-duty jobs, with severe conduction block but without severe axonal loss were recruited. The severity of ulnar nerve compression was quantified based on electrophysiologic studies, Jebsen-Taylor Hand Function Test, Jamar dynamometer, and Semmes-Weinstein Monofilaments Test. UNE resulted in a reduction in hand strength without any significant impact on fine motor dexterity. The 4 laborers whose work required strong hand grip found this debilitating. Severe UNE affects the hand function of heavy manual workers by impeding their grip and pinch strengths. However, UNE does not affect tasks requiring fine hand dexterity.
The Development of a Virtual Community of Practices Using Electronic Mail and Communicative Genres
Authors: Zucchermaglio Cristina , Talamo Alessandra
Published: June 2003

This article uses the notion of genre repertoire to examine electronic-mail communication exchanged in a period of three years by an interorganizational community of software developers (727 e-mail messages in total). It analyzes the development of this virtual work community by considering the use of communicative genres with respect to (1) the resources offered by the electronic-mail system, (2) the temporal development of the project in which the participants were engaged, and (3) the developing relationship between community members. The study shows that the community organized its communicative interactions mainly as informal exchanges between peers rather than as formal exchanges that followed the structure of an interorganizational project. The messages were strongly affected by the use of a system of electronic mail and changed as the community members' relationships developed.
Working Together in a Divided Society
Authors: Hargie Owen , Dickson David , Nelson Seanenne
Published: June 2003

During the past 30 years, workplaces in Northern Ireland have suffered the consequences of ongoing political and religious conflicts, often resulting in severe operational disruptions and financial loss. Yet little if any research has explored organizational communication in divided workplaces such as those in Northern Ireland. This study examines intergroup relations and communication within such settings. It employs a range of research methodologies to ascertain the perceptions and perspectives of employees in four of the largest workplaces in Northern Ireland, including their perceptions about appropriate ways to deal with contentious issues. The findings should be relevant to those interested in communication in diverse workplaces.
The Emergence of Technical Communication in China—Yi Jing (I Ching)
Authors: Ding Daniel D.
Published: June 2003

To promote intercultural understanding in technical communication, this article studies Yi Jing as a technical instructions manual, the first technical communication book in China. After examining the information in Yi Jing and its organization as well as a modern Chinese instructional manual, the author claims that Yi Jing developed the theory that context and individual objects should be seen as a unity and thus established a tradition that Chinese instructional manuals observe: focusing on contextual information instead of action-oriented instructions for task performance. The author compares the Chinese manual and an American one to support his claim that Yi Jing 's philosophy helps us uncover a pattern of meaning in modern Chinese instructional manuals.
Professional Communication in the Learning Marketspace
Authors: Duin Ann Hill , Starke-Meyerring Doreen
Published: June 2003

As society increasingly inhabits digital spaces in addition to physical places, the environment in which professional communication programs function undergoes fundamental change. The specific dynamics of these digital spaces have resulted in the emergence of learning marketspaces and present a program with three choices for positioning itself: (1) staying at its homestead, its own individual home page; (2) paying rent for a space in someone else's learning marketspace; or (3) partnering to build a learning marketspace. This article addresses the third choice and suggests how programs may go about partnering to build a learning marketspace. The authors examine the following questions: Why partner to develop a learning marketspace? What are critical components of a learning marketspace for professional communication? and How might we assess a program's readiness for partnering in the learning marketspace?
Coding of Sensory Signals by Neuronal Populations: The Role of Correlated Activity
Authors: Panzeri Stefano , Pola Gianni , Petersen Rasmus S.
Published: June 2003

How is sensory information encoded by the patterns of action potentials emitted by ensembles of neurons? Computational methods have recently been applied to this fundamental question and have found, both in the somatosensory and visual system, that the basic unit of information transmission is the timing of individual spikes. In systems studied to date, the neuronal population codes appear to be simple ones that do not rely on complex patterns of correlated spikes.
Calcium-Activated Potassium Channels: Multiple Contributions to Neuronal Function
Authors: Faber E. S. Louise , Sah Pankaj
Published: June 2003

Calcium-activated potassium channels are a large family of potassium channels that are found throughout the central nervous system and in many other cell types. These channels are activated by rises in cytosolic calcium largely in response to calcium influx via voltage-gated calcium channels that open during action potentials. Activation of these potassium channels is involved in the control of a number of physiological processes from the firing properties of neurons to the control of transmitter release. These channels form the target for modulation for a range of neurotransmitters and have been implicated in the pathogenesis of neurological and psychiatric disorders. Here the authors summarize the varieties of calcium-activated potassium channels present in central neurons and their defining molecular and biophysical properties.
How we Walk: Central Control of Muscle Activity during Human Walking
Authors: Nielsen Jens Bo
Published: June 2003

Recent advances in noninvasive electrophysiological and brain imaging techniques have made investigation of the central control of human walking possible. We are thus now able to ask in what way the motor control circuitries in the human brain and spinal cord have been modified in order to control bipedal walking. This information is of importance not only for our understanding of basic control strategies and paradigms but also for future attempts at rehabilitating the gait ability of patients after lesions of the brain and spinal cord.
GABARAP: Lessons for Synaptogenesis
Authors: Coyle Joseph E. , Nikolov Dimitar B.
Published: June 2003

The clustering of neurotransmitter receptors at the postsynaptic terminals is a critical requirement for efficient neurotransmission and neuronal communication. This process is facilitated by adaptor proteins, which bridge the postsynaptic receptors and the underlying cytoskeleton. One such molecule, the GABAA receptor-associated protein, GABARAP, was identified as a potential linker between GABAA receptors and microtubules. GABARAP belongs to an expanding family of proteins that are implicated in a variety of intracellular transport processes. GABARAP has been shown to interact with myriad binding partners, including the γ2 subunit of the GABAA receptor, tubulin and microtubules, the N-ethyl maleimide sensitive factor, gephyrin, and the transferin receptor. The recent determination of the GABARAP crystal structure has revealed individual GABARAP domains, motifs, and surface regions involved in specific protein-protein interactions. Currently, a more general role is emerging for GABARAP, including shipping GABAA receptors to and from the cell surface, organizing them into postsynaptic clusters, and regulating the steady-state receptor density.
The Pharmacology of Vertebrate Spinal Central Pattern Generators
Authors: Alford Simon , Schwartz Eric , Di Prisco Gonzalo Viana
Published: June 2003

Central pattern generators are networks of neurons capable of generating an output pattern of spike activity in a relatively stereotyped, rhythmic pattern that has been found to underlie vital functions like respiration and locomotion. The central pattern generator for locomotion in vertebrates seems to share some basic building blocks. Activation and excitation of activity is driven by descending, sensory, and intraspinal glutamatergic neurons. NMDA receptor activation may also lead to the activation of oscillatory properties in individual neurons that depend on an array of ion channels situated in those neurons. Coordination across joints or the midline of the animal is driven primarily by glycinergic inhibition. In addition to these processes, numerous modulatory mechanisms alter the function of the central pattern generator. These include metabotropic amino acid receptors activated by rhythmic release of glutamate and GABA as well as monoamines, ACh, and peptides. Function and stability of the central pattern generator is also critically dependent on the array of ion channels found in neurons that compose these oscillators, including Ca2+ and voltage-gated K+ channels and Ca2+ channels.
Strategies for Integrating Medicare and Medicaid: Design Features and Incentives
Authors: Miller Edward Alan , Weissert William G.
Published: June 2003

In a typical third-party payer situation—representative of most U.S. health care delivery—the payer is likely to have interests that are at odds with the patient and provider. The separation and overlap between Medicare and Medicaid for individuals eligible for both programs introduces an additional level of complexity: multiple masters over plans, providers, and patients. This creates opportunities for shifting costs and administrative burdens between states and the federal government, providers and governments, and patients and everyone else. Program designers who wish to minimize unwanted consequences must find ways to structure their programs to produce financial incentives that encourage the pursuit of societal goals, including appropriately shared intergovernmental responsibilities and appropriate plan, provider, and patient behavior. Here the authors review nine federal and state initiatives that use varying strategies to integrate Medicare and Medicaid services for vulnerable populations. For each initiative, the authors examine and critique program design features in three areas: (1) eligibility determination, (2) finance and administration, and (3) service delivery. They find a few strengths and many weaknesses in design. Future efforts would be well served by carefully considering the incentive structures designed into these initiatives and working to improve them in the next generation of Medicare-Medicaid integration efforts.
The Association between Three Different Measures of Health Status and Satisfaction among Patients with Diabetes
Authors: Kerr Eve A. , Smith Dylan M. , Kaplan Sherrie H. , Hayward Rodney A.
Published: June 2003

Studies suggest that health status influences patient satisfaction, but little work has examined the influence of different measures of health status on satisfaction. The authors examined whether the association between health status and satisfaction varied for different measures of health status among 2000 diabetic patients receiving care across 25 Veterans Affairs facilities. Health status was measured using (1) the diabetes-related components of the Total Illness Burden Index (DM TIBI), a measure of diabetes severity and comorbidities; (2) the Short Form 36 (SF-36) Physical Function Index (PFI10); and (3) the SF-36 general health perceptions question (SF-1). Satisfaction was measured both by a 5-item scale on satisfaction with patient-provider communication and by a single item on overall diabetes care satisfaction. In adjusted models, worse health on all three health status measures correlated with lower satisfaction, but the DM TIBI explained more of the variation in satisfaction than either the PFI10 or SF-1. Moreover, when the DM TIBI was added to the model containing PFI10, PFI10 was no longer significantly associated with satisfaction. In this diabetes population, health status appears to have a substantial impact on patient satisfaction, and this effect is considerably greater for diabetes severity than for physical functioning.
Differential Adoption of Pharmacotherapy Recommendations for Type 2 Diabetes by Generalists and Specialists
Authors: Pugh Mary Jo V. , Anderson Jennifer , Pogach Leonard M. , Berlowitz Dan R.
Published: June 2003

Newer, multimedication (novel) regimens provide better glycemic control for many type 2 diabetics when sulfonylurea monotherapy (traditional) becomes ineffective. Because better glycemic control is associated with decreased likelihood of complications and lower utilization and cost of care, the authors examined change in prescribing patterns for veterans with type 2 diabetes between FY 97 and 99. They classified medication regimens as traditional and novel based on the combination of diabetes medications patients received at the end of each year. Multivariate logistic regression analyses controlling for disease severity indicated that patients were more likely to receive novel regimens over time, but those seen only in primary care were less likely to receive novel regimens than those previously seen by a specialist. Geographic differences and differences in how recommendations were implemented by generalists and specialists suggest that diffusion of innovations theory may help explain variations in practice and guide interventions designed to translate research into practice.
Medicare Maximization by State Medicaid Programs: Effects on Medicare Home Care Utilization
Authors: Anderson Wayne L. , Norton Edward C. , Dow William H.
Published: June 2003

Medicaid programs in some states have attempted to shift home health care costs to Medicare by using retrospective billing practices. The authors explored whether retrospective billing practices increase Medicare utilization for dual eligibles by analyzing primary data on the existence of retrospective billing practices collected from 47 state Medicaid offices complemented with individual-level secondary data from the 1992-1997 Medicare Current Beneficiary Survey. An individual-level random effects model was used to estimate the increase in the probability and amount of Medicare home care visits from state retrospective billing practices. Retrospective billing practices were found not to affect either the probability or the amount of Medicare home care visits in these data, but the significant inverse relationship found between Medicaid and Medicare visits shows that states with high Medicaid utilization have opportunity to shift some of these visits to Medicare.
Searching for and Selecting a Nursing Facility
Authors: Castle Nicholas G.
Published: June 2003

In this study, the authors present findings from 306 resident interviews matched with 306 family member interviews examining factors associated with both the search for and selection of a nursing facility. For many elders transitioning into a nursing facility, the facility becomes their home, and the average cost of residing in that home is high. As such, searching for and selection of a facility has important consequences. The authors found that residents are not very influential in these processes. Second, they found very few proactive nursing facility choices were made by either residents or family members. Third, the choices made were seldom based on the quality of the facility. Fourth, prior knowledge of the chosen facility was limited. Finally, the authors also show that the time taken to choose a facility was in most cases extremely limited.
VHA Enrollees' Health Care Coverage and Use of Care
Authors: Shen Yujing , Hendricks Ann , Zhang Shuo , Kazis Lewis E.
Published: June 2003

The authors examined health care coverage for Veterans' Health Administration (VHA) enrollees and how their reliance on VHA care varies by coverage, using the largest and most detailed survey of veterans using VHA services ever conducted. The results showed that a majority of veterans who use VHA services have alternative health care coverage and that most of them use both VHA and non-VHA health care. The findings have important implications for quality of care and coordination of care.
A Boost or Bust for Democracy?
Authors: Johnson Thomas J. , Kaye Barbara K.
Published: June 2003

This study employed an online survey of 442 politically interested Web users during the 2000 presidential election to examine the extent to which relying on the Web for political information influences political interest, campaign interest, political involvement, likelihood of voting, and voting behavior after controlling for demographics, political attitudes and use of the traditional media. Results from this study are compared to a similar one conducted during the 1996 presidential campaign. The respondents were highly interested in politics in general, were very interested in the 2000 campaign, expressed a high likelihood to vote, and almost all did vote. The Internet appears to engage people politically as almost two-thirds claim that their involvement in politics has increased or greatly increased since they first became online users. Politically interested Internet users were more likely to report in 2000 than 1996 that they felt they had power to bring about political change, that they were very interested in the presidential campaign, and that they were more likely to vote. The Web appears to be at least partially responsible for this increase in civic engagement as reliance on the Web was the strongest predictor of political attitudes.
Is Negative Advertising Effective for Female Candidates?
Authors: Gordon Ann , Shafie David M. , Crigler Ann N.
Published: June 2003

Female candidates sometimes are discouraged from negative campaigning because they would risk voter backlash by defying gender stereotypes. In this experiment, a negative television campaign advertisement was manipulated to control for the candidate's gender, issue content, and the character traits emphasized in the narration. The female candidate's support was not diminished because of the attack upon her opponent. The findings show that in low-information contests, female candidates are assumed to be weaker on “male” issues. However, when the female candidate used a “male” issue as the basis of an attack upon her male opponent, she was judged more competent on the issue. This suggests that negative advertising could be an effective tool to neutralize the disadvantages caused by gender stereotypes.
News and Elections
Authors: Semetko Holli A. , Schoenbach Klaus
Published: June 2003

This article looks at how political reporting has changed over time in the Bild, Germany's most widely read newspaper. The authors content analyzed the political coverage during the seven weeks prior to the federal elections in 1990, 1994, 1998, and 2002. They found increasing emphasis on the campaign in the news from one election to the next, which can be explained by the fact that the elections themselves became more competitive and thus had more news value. They also find increasing negativity toward the two main parties between 1990 and 1998 and toward the SPD (Social Democratic Party) since 1998. The Bild's editorial decision to include more commentary pieces in 2002 is at least in part responsible for the strongly negative coverage of the SPD and the chancellor in that election, but the greater negativity was also due to the increased volume of other political news stories that also contained negative evaluations.
Debating the Debate
Authors: Tsfati Yariv
Published: June 2003

Rather than studying the effects of a programmed debate per se, this article examines the “total information environment” that surrounds the debate. A model explaining how people make judgments about the “winner” of a debate is suggested and tested on survey data ( N = 748) collected in the days following the second 1996 presidential debate. Results demonstrate that consumption of debate-related news coverage, interpersonal discussion about the debate, and prior candidate attitudes are associated with perceptions of the winner of the debate. In addition, exposure to news coverage of the debate significantly interacted with exposure to the actual debate, so that the impact of news coverage was stronger for those watching little of the actual debate.
From the Inside Out
Authors: Hughes Sallie
Published: June 2003

This article addresses how to create democratic news media that foster participatory citizenship and government accountability. Using the case of Mexico, where journalism underwent a deep transformation in the 1980s and 1990s, the research finds that societal-level changes such as democratization and economic liberalization are only part of the explanation. What went on inside news organizations determined whether media took on a civic orientation enabling the creation of a public sphere, resisted societal-level change altogether, or reacted to only market-based cues. The result of these disparate transformations was the dissolution of an authoritarian institution into three competing models of news production with profoundly different sociopolitical implications. The study also discusses the application of sociological theory on organizations and institutions to the question of journalistic change in some depth.
The Political Content of Late Night Comedy
Authors: Niven David , Lichter S. Robert , Amundson Daniel
Published: June 2003

During the 2000 national election season, there was unprecedented attention paid by the media, and by presidential campaigns, to the political content of late night comedy shows such as the Tonight Show with Jay Leno and the Late Show with David Letterman. Focusing on the more than thirteen thousand jokes about U.S. political figures from 1996 to 2000 on late night comedy talk shows, this study explores the choice of targets and subjects of political humor. The authors find that late night humor is heavily centered on the president and top presidential contenders, that the various late night shows tend to exhibit the same patterns in their choice of targets, and that the humor is generally devoid of issue content.
The multidrug resistance-associated protein 3 (MRP3) is associated with a poor outcome in childhood ALL and may account for the worse prognosis in male patients and T-cell immunophenotype
Authors: Steinbach Daniel , Wittig Susann , Cario Gunnar , Viehmann Susanne , Mueller Angelika , Gruhn Bernd , Haefer Ralf , Zintl Felix , Sauerbrey Axel
Published: June 2003

The family of multidrug resistance-associated proteins (MRPs) belongs to the superfamily of adenosine triphosphate-binding-cassette (ABC) transporters, which have the ability to function as outward pumps for chemotherapeutic drugs and therefore might be involved in drug resistance. In this study the expression of the MRP2, MRP3, MRP4, MRP5, and SMRP genes was measured using TaqMan real-time polymerase chain reaction (PCR) in 103 children with previously untreated acute lymphoblastic leukemia (ALL) (precursor B-cell ALL [B-ALL], n = 71; T-cell ALL [T-ALL], n = 32). All 5 genes were expressed with a great variability. Only MRP3 expression was associated with a significantly worse prognosis (P = .008). The median expression of MRP3 was 10-fold higher in T-ALL than in precursor B-ALL (P < .001) and 4-fold higher in male patients than in female patients (P < .001). The prognostic impact of MRP3 was independent of immunophenotype or sex. Higher levels of MRP3 were found in patients with a poor in vivo response to prednisone, but this could not be confirmed in an independent case-control study (40 patients) for prednisone response. In healthy donors, the median expression of MRP4 was 4-fold higher in bone marrow and 8-fold higher in CD34+ stem cells compared with peripheral blood (P = .002). Our results suggest that MRP3 is involved in drug resistance in childhood ALL. It therefore represents an interesting target to overcome multidrug resistance. High levels of MRP3 could possibly be the reason for the poorer prognosis of male patients or patients who have T-ALL. Similar to other members of the family of ABC transporters, MRP4 seems to be a marker for immature stem cells. (Blood. 2003;102:4493-4498)
A novel EVI1 gene family, MEL1, lacking a PR domain (MEL1S) is expressed mainly in t(1;3)(p36;q21)-positive AML and blocks G-CSF–induced myeloid differentiation
Authors: Nishikata Ichiro , Sasaki Hidenori , Iga Mutsunori , Tateno Yoko , Imayoshi Suzuko , Asou Norio , Nakamura Takuro , Morishita Kazuhiro
Published: June 2003

We have identified a novel gene MEL1 (MDS1/EVI1-like gene 1) encoding a zinc finger protein near the breakpoint of t(1; 3)(p36;q21)-positive human acute myeloid leukemia (AML) cells. Here, we studied the structure, expression pattern, and function of MEL1 in leukemia cells. In this study, we have identified 3 transcription start sites, 1 in exon 1 and 2 in exon 2, and 2 kinds of translation products, 170 kDa (MEL1) and 150 kDa (MEL1S). Notably, the 150-kDa band of MEL1S was detected mainly in the t(1;3)(p36;q21)-positive AML cells. By immunoblot analysis and proteolytic mapping, it is suggested that the 150-kDa band of MEL1S in the leukemia cells is translated from the internal initiation codon ATG597 in exon 4 and is mostly lacking the amino-terminal PR domain of MEL1. By the cyclic amplification and selection of targets (CASTing) method for identifying consensus sequences, it was shown that the consensus sequences of MEL1 were included in 2 different consensus sequences for DNA-binding domain 1 and 2 (D1-CONS and D2-CONS) of EVI1. In reporter gene assays, MEL1S activated transcription via binding to D2-CONS; however, the fusion of MEL1 or MEL1S to GAL4 DNA-binding domain (DBD) made them GAL4 binding site–dependent transcriptional repressors. Moreover, overexpression of MEL1S blocked granulocytic differentiation induced by granulocyte colony-stimulating factor (G-CSF) in interleukin-3 (IL-3)–dependent murine myeloid L-G3 cells, while MEL1 could not block the differentiation. Thus, it is likely that overexpression of the zinc finger protein lacking the PR domain (EVI1 and MEL1S) in the leukemia cells is one of the causative factors in the pathogenesis of myeloid leukemia.
CC chemokine ligand 20 partially controls adhesion of naive B cells to activated endothelial cells under shear stress
Authors: Meissner Anja , Zilles Olaf , Varona Rosa , Jozefowski Katrin , Ritter Uwe , Marquez Gabriel , Hallmann Rupert , Körner Heinrich
Published: June 2003

Chemokines are thought to control lymphocyte recruitment to the inflamed endothelium. To dissect chemokine-mediated adhesion, binding of ex vivo isolated splenocytes to tumor necrosis factor (TNF)–activated endothelial cells was analyzed under shear stress. We observed specific adhesion of naive follicular B cells, which could be blocked by pertussis toxin. This indicated a G protein–mediated binding and pointed at a contribution of chemokine receptors to B-cell adhesion. Analysis of chemokines expressed by TNF-activated endothelial cells showed that CC chemokine ligand 2 (CCL2), CCL17, and CCL20 were up-regulated. Only on follicular B cells was the cognate receptor for CCL20, CC chemokine receptor 6 (CCR6), expressed strongly, and a functional transmigration assay with CCR6-negative B cells demonstrated conclusively the sole signaling of CCL20 through CCR6. Desensitization of CCR6 on naive B cells with CCL20 resulted in receptor down-regulation and reduced B-cell adhesion. We conclude that CCL20 plays a vital role in B-cell adhesion to the inflamed endothelium.