bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiview radial catadioptric imaging for scene capture
Authors: Kuthirummal Sujit , Nayar Shree K.
Published: July 2006

In this paper, we present a class of imaging systems, called
radial imaging systems
, that capture a scene from a large number of view-points within a single image, using a camera and a curved mirror. These systems can recover scene properties such as geometry, reflectance, and texture. We derive analytic expressions that describe the properties of a complete family of radial imaging systems, including their loci of viewpoints, fields of view, and resolution characteristics. We have built radial imaging systems that, from a single image, recover the frontal 3D structure of an object, generate the complete texture map of a convex object, and estimate the parameters of an analytic BRDF model for an isotropic material. In addition, one of our systems can recover the complete geometry of a convex object by capturing only two images. These results show that radial imaging systems are simple, effective, and convenient devices for a wide range of applications in computer graphics and computer vision.
Fast separation of direct and global components of a scene using high frequency illumination
Authors: Nayar Shree K. , Krishnan Gurunandan , Grossberg Michael D. , Raskar Ramesh
Published: July 2006

We present fast methods for separating the direct and global illumination components of a scene measured by a camera and illuminated by a light source. In theory, the separation can be done with just two images taken with a high frequency binary illumination pattern and its complement. In practice, a larger number of images are used to overcome the optical and resolution limitations of the camera and the source. The approach does not require the material properties of objects and media in the scene to be known. However, we require that the illumination frequency is high enough to adequately sample the global components received by scene points. We present separation results for scenes that include complex interreflections, subsurface scattering and volumetric scattering. Several variants of the separation approach are also described. When a sinusoidal illumination pattern is used with different phase shifts, the separation can be done using just three images. When the computed images are of lower resolution than the source and the camera, smoothness constraints are used to perform the separation using a single image. Finally, in the case of a static scene that is lit by a simple point source, such as the sun, a moving occluder and a video camera can be used to do the separation. We also show several simple examples of how novel images of a scene can be computed from the separation results.
Spectral surface quadrangulation
Authors: Dong Shen , Bremer Peer-Timo , Garland Michael , Pascucci Valerio , Hart John C.
Published: July 2006

Resampling raw surface meshes is one of the most fundamental operations used by nearly all digital geometry processing systems. The vast majority of this work has focused on triangular remeshing, yet quadrilateral meshes are preferred for many surface PDE problems, especially fluid dynamics, and are best suited for defining Catmull-Clark subdivision surfaces. We describe a fundamentally new approach to the quadrangulation of manifold polygon meshes using Laplacian eigenfunctions, the natural harmonics of the surface. These surface functions distribute their extrema evenly across a mesh, which connect via gradient flow into a quadrangular base mesh. An iterative relaxation algorithm simultaneously refines this initial complex to produce a globally smooth parameterization of the surface. From this, we can construct a well-shaped quadrilateral mesh with very few extraordinary vertices. The quality of this mesh relies on the initial choice of eigenfunction, for which we describe algorithms and hueristics to efficiently and effectively select the harmonic most appropriate for the intended application.
The cartoon animation filter
Authors: Wang Jue , Drucker Steven M. , Agrawala Maneesh , Cohen Michael F.
Published: July 2006

We present the "Cartoon Animation Filter", a simple filter that takes an arbitrary input motion signal and modulates it in such a way that the output motion is more "alive" or "animated". The filter adds a smoothed, inverted, and (sometimes) time shifted version of the second derivative (the acceleration) of the signal back into the original signal. Almost all parameters of the filter are automated. The user only needs to set the desired strength of the filter. The beauty of the animation filter lies in its simplicity and generality. We apply the filter to motions ranging from hand drawn trajectories, to simple animations within PowerPoint presentations, to motion captured DOF curves, to video segmentation results. Experimental results show that the filtered motion exhibits anticipation, follow-through, exaggeration and squash-and-stretch effects which are not present in the original input motion data.
Heads up!
Authors: Lee Sung-Hee , Terzopoulos Demetri
Published: July 2006

Unlike the human face, the neck has been largely overlooked in the computer graphics literature, this despite its complex anatomical structure and the important role that it plays in supporting the head in balance while generating the controlled head movements that are essential to so many aspects of human behavior. This paper makes two major contributions. First, we introduce a biomechanical model of the human head-neck system. Emulating the relevant anatomy, our model is characterized by appropriate kinematic redundancy (7 cervical vertebrae coupled by 3-DOF joints) and muscle actuator redundancy (72 neck muscles arranged in 3 muscle layers). This anatomically consistent biomechanical model confronts us with a challenging motor control problem, even for the relatively simple task of balancing the mass of the head in gravity atop the cervical spine. Hence, our second contribution is a novel neuromuscular control model for human head animation that emulates the relevant biological motor control mechanisms. Incorporating low-level reflex and high-level voluntary sub-controllers, our hierarchical controller provides input motor signals to the numerous muscle actuators. In addition to head pose and movement, it controls the tone of mutually opposed neck muscles to regulate the stiffness of the head-neck multibody system. Employing machine learning techniques, the neural networks within our neuromuscular controller are trained offline to efficiently generate the online pose and tone control signals necessary to synthesize a variety of autonomous movements for the behavioral animation of the human head and face.
Real-time video abstraction
Authors: Winnemöller Holger , Olsen Sven C. , Gooch Bruce
Published: July 2006

We present an automatic, real-time video and image abstraction framework that abstracts imagery by modifying the contrast of visually important features, namely luminance and color opponency. We reduce contrast in low-contrast regions using an approximation to anisotropic diffusion, and artificially increase contrast in higher contrast regions with difference-of-Gaussian edges. The abstraction step is extensible and allows for artistic or data-driven control. Abstracted images can optionally be stylized using soft color quantization to create cartoon-like effects with good temporal coherence. Our framework design is highly parallel, allowing for a GPU-based, real-time implementation. We evaluate the effectiveness of our abstraction framework with a user-study and find that participants are faster at naming abstracted faces of known persons compared to photographs. Participants are also better at remembering abstracted images of arbitrary scenes in a memory task.
A Conversation with Leo Chang of ClickShift
Authors: O'Hanlon Charlene
Published: July 2006

To explore this month’s theme of component technologies, we brought together two engineers with lots of experience in the field to discuss some of the current trends and future direction in the world of software components. Queue Editorial board member Terry Coatta is the director of software development at GPS Industries. His expertise is in distributed component systems such as CORBA, EJB, and COM. He joins in the discussion with Leo Chang, the cofounder and CTO of ClickShift, an online campaign optimization and management company. Chang also cofounded a company called flyswat, which was purchased by NBCi, and served as the vice president of software development at Savi Technology.
The Rise and Fall of CORBA
Authors: Henning Michi
Published: July 2006

Depending on exactly when one starts counting, CORBA is about 10-15 years old. During its lifetime, CORBA has moved from being a bleeding-edge technology for early adopters, to being a popular middleware, to being a niche technology that exists in relative obscurity. It is instructive to examine why CORBA—despite once being heralded as the “next-generation technology for e-commerce”—suffered this fate. CORBA’s history is one that the computing industry has seen many times, and it seems likely that current middleware efforts, specifically Web services, will reenact a similar history.
Review of "Agile Estimating and Planning by Mike Cohn," Prentice Hall PTR, 2005, $44.99, ISBN: 0131479415.
Authors: Moreno A.
Published: July 2006

Review of "Agile Estimating and Planning by Mike Cohn," Prentice Hall PTR, 2005, $44.99, ISBN: 0131479415.
Calendar
Authors: O'Hanlon Charlene
Published: July 2006

O’Reilly Where 2.0
News 2.0
Authors: Stanik John
Published: July 2006

Programmers at Play
Review of "Open Source Wireless Java Tools Suite by Robert Virkus," Apress, 2005, $39.99, ISBN: 1590595033.
Authors: Kuc Bernard
Published: July 2006

Review of "Open Source Wireless Java Tools Suite by Robert Virkus," Apress, 2005, $39.99, ISBN: 1590595033.
Review of "Securing Storage: A Practical Guide to SAN and NAS Security by Himanshu Dwivedi," Addison-Wesley Professional, 2005, $49.99, ISBN: 0321349954.
Authors: Lloret Jose
Published: July 2006

Review of "Securing Storage: A Practical Guide to SAN and NAS Security by Himanshu Dwivedi," Addison-Wesley Professional, 2005, $49.99, ISBN: 0321349954.
Prototyping time- and space-efficient computations of algebraic operations over dynamically reconfigurable systems modeled by rewriting-logic
Authors: Ayala-Rincón M. , Llanos C. H. , Jacobi R. P. , Hartenstein R. W.
Published: July 2006

Many algebraic operations can be efficiently implemented as pipe networks in arrays of functional units such as systolic arrays that provide a large amount of parallelism. However, the applicability of classical systolic arrays is restricted to problems with strictly regular data dependencies yielding only arrays with uniform linear pipes. This limitation can be circumvented by using reconfigurable systolic arrays or reconfigurable data path arrays, where the node interconnections and operations can be redefined even at run time. In this context, several alternative reconfigurable systolic architectures can be explored and powerful tools are needed to model and evaluate them. Well-known rewriting-logic environments such as ELAN and Maude can be used to specify and simulate complex application-specific integrated systems. In this article we propose a methodology based on rewriting-logic which is adequate to quickly model and evaluate reconfigurable architectures (RA) in general and, in particular, reconfigurable systolic architectures. As an interesting case study we apply this rewriting-logic modeling methodology to the space-efficient treatment of the Fast-Fourier Transform (FFT). The FFT prototype conceived in this way, has been specified and validated in VHDL using the Quartus II system.
Implicit grading of multiple path delay faults
Authors: Padmanaban Saravanan , Tragoudas Spyros
Published: July 2006

The problem of fault grading for multiple path delay faults is introduced and a method of obtain exact coverage is presented. The faults are represented and manipulated as combinational sets using zero-suppressed binary decision diagrams. The presented methodology for fault grading uses only a polynomial number of zero-suppressed binary decision diagram operations. The efficiency of the proposed method is demonstrated by the experimental results on the ISCAS'85 and ISCAS'89 benchmarks.
On the construction of zero-deficiency parallel prefix circuits with minimum depth
Authors: Zhu Haikun , Cheng Chung-Kuan , Graham Ronald
Published: July 2006

A parallel prefix circuit has
n
inputs
x
1
,
x
2
, …,

x
n

, and computes the
n
outputs

y
i

=

x
i

•
x

i
−1

•…•
x
1
, 1 ≤
i
≤
n
, in parallel, where • is an arbitrary binary associative operator. Snir proved that the depth
t
and size
s
of any parallel prefix circuit satisfy the inequality
t
+
s
≥2
n
−2. Hence, a parallel prefix circuit is said to be of zero-deficiency if equality holds. In this article, we provide a different proof for Snir's theorem by capturing the structural information of zero-deficiency prefix circuits. Following our proof, we propose a new kind of zero-deficiency prefix circuit
Z
(
d
) by constructing a prefix circuit as wide as possible for a given depth
d
. It is proved that the
Z
(
d
) circuit has the minimal depth among all possible zero-deficiency prefix circuits.
Reducing energy consumption of multiprocessor SoC architectures by exploiting memory bank locality
Authors: Kandemir Mahmut Taylan
Published: July 2006

The next generation embedded architectures are expected to accommodate multiple processors on the same chip. While this makes interprocessor communication less costly as compared to traditional high-end parallel machines, it also makes off-chip requests very costly. In particular, frequent off-chip memory accesses do not only increase execution cycles but also increase overall power consumption. One way of alleviating this power problem is to divide the off-chip memory into multiple banks, each of which can be power-controlled independently using low-power operating modes.In this article, we focus on a multiprocessor-system-on-a-chip (MPSoC) architecture with a banked memory system, and show how code and data optimizations can help us reduce memory energy consumption for embedded applications with regular data access patterns, for example, those from the embedded image and video processing domain. This is achieved by ensuring bank locality, which means that each processor localizes its accesses into a small set of banks in a given time period. We present a mathematical formulation of the bank locality problem. Our formulation is based on constructing a set of matrix equations that capture the mappings between the data, computation, processor, and memory bank spaces. Based on this formulation, we propose a heuristic solution to the bank locality problem under different scenarios. Our solution involves an iterative process through which we try to satisfy as many matrix constraints as possible; the unsatisfied constraints represent the degree of degradation in bank locality. Finally, we report extensive experimental results showing the effectiveness of our strategy in practice. Our results show that the proposed solution improves bank locality significantly, and reduces the overall memory system energy consumption by up to 34% over an approach that makes use of the low-power modes but does not employ our strategy.
Concurrent testing of digital microfluidics-based biochips
Authors: Su Fei , Ozev Sule , Chakrabarty Krishnendu
Published: July 2006

We present a concurrent testing methodology for detecting catastrophic faults in digital microfluidics-based biochips and investigate the related problems of test planning and resource optimization. We first show that an integer linear programming model can be used to minimize testing time for a given hardware overhead, for example, droplet dispensing sources and capacitive sensing circuitry. Due to the NP-complete nature of the problem, we also develop efficient heuristic procedures to solve this optimization problem. We apply the proposed concurrent testing methodology to a droplet-based microfluidic array that was fabricated and used to perform multiplexed glucose and lactate assays. Experimental results show that the proposed test approach interleaves test application with the biomedical assays and prevents resource conflicts. The proposed method is therefore directed at ensuring high reliability and availability of bio-MEMS and lab-on-a-chip systems, as they are increasingly deployed for safety-critical applications.
Warp Processors
Authors: Lysecky Roman , Stitt Greg , Vahid Frank
Published: July 2006

We describe a new processing architecture, known as a warp processor, that utilizes a field-programmable gate array (FPGA) to improve the speed and energy consumption of a software binary executing on a microprocessor. Unlike previous approaches that also improve software using an FPGA but do so using a special compiler, a warp processor achieves these improvements completely transparently and operates from a standard binary. A warp processor dynamically detects the binary's critical regions, reimplements those regions as a custom hardware circuit in the FPGA, and replaces the software region by a call to the new hardware implementation of that region. While not all benchmarks can be improved using warp processing, many can, and the improvements are dramatically better than those achievable by more traditional architecture improvements. The hardest part of warp processing is that of dynamically reimplementing code regions on an FPGA, requiring partitioning, decompilation, synthesis, placement, and routing tools, all having to execute with minimal computation time and data memory so as to coexist on chip with the main processor. We describe the results of developing our warp processor. We developed a custom FPGA fabric specifically designed to enable lean place and route tools, and we developed extremely fast and efficient versions of partitioning, decompilation, synthesis, technology mapping, placement, and routing. Warp processors achieve overall application speedups of 6.3X with energy savings of 66% across a set of embedded benchmark applications. We further show that our tools utilize acceptably small amounts of computation and memory which are far less than traditional tools. Our work illustrates the feasibility and potential of warp processing, and we can foresee the possibility of warp processing becoming a feature in a variety of computing domains, including desktop, server, and embedded applications.
Simultaneous placement with clustering and duplication
Authors: Chen Gang , Cong Jason
Published: July 2006

Clustering, duplication, and placement are critical steps in a cluster-based FPGA design flow. Clustering has a great impact on the wirelength, timing, and routability of a circuit. Logic duplication is an effective method for improving performance while maintaining the logic equivalence of a circuit. Based on several novel algorithmic contributions, we present an efficient and effective algorithm named
SPCD
(simultaneous placement with clustering and duplication) which performs clustering and duplication
during
placement for wirelength and timing minimization. First, we incorporate a path counting-based net weighting scheme for more effective timing optimization. Secondly, we introduce a novel method of moving a fragment of a cluster (called a
fragment level move
) during placement to optimize the clustering structure. To reduce the critical path detour during legalization from a more global perspective, we also introduce the notions of a
monotone region
and a
global monotone region
in which improvement to the local/global path detour is guaranteed. Furthermore, we introduce a notion of a
constrained gain graph
to embed all complex FPGA clustering constraints, and implement an optimal incremental legalization algorithm under such constraints. Finally, in order to reduce the circuit area, we formulate a timing-constrained global
redundancy removal
problem and propose a heuristic solution. Our SPCD algorithm outperforms a widely used academic FPGA placement flow,
T-VPack + VPR
, with an average reduction of 31% in the longest path estimate delay and 18% in the routed delay. We also apply our SPCD algorithm to Altera's Stratix architecture in a commercial FPGA implementation flow (
Quartus II
4.0). The routed result achieved by our SPCD algorithm outperforms
VPR
by 20% and outperforms
Quartus II
4.0 by 4%.
A stimulus-free graphical probabilistic switching model for sequential circuits using dynamic bayesian networks
Authors: Bhanja Sanjukta , Lingasubramanian Karthikeyan , Ranganathan N.
Published: July 2006

We propose a novel, nonsimulative probabilistic model for switching activity in sequential circuits, capturing both spatio-temporal correlations at internal nodes and higher order temporal correlations due to feedback. This model, which we refer to as the temporal dependency model (TDM), can be constructed from the logic structure and is shown to be a dynamic Bayesian network. Dynamic Bayesian networks are extremely powerful in modeling high order temporal, as well as spatial, correlations; TDM is an exact model for the underlying conditional independencies. The attractive feature of this graphical representation of the joint probability function is not only that it makes the dependency relationships amongst nodes explicit, but it also serves as a computational mechanism for probabilistic inference. We report average errors in switching probability of 0.006, with errors tightly distributed around mean error values, on ISCAS'89 benchmark circuits involving up to 10000 signals.
Blur filtration fails to preserve privacy for home-based video conferencing
Authors: Neustaedter Carman , Greenberg Saul , Boyle Michael
Published: July 2006

Always-on video provides rich awareness for distance-separated coworkers. Yet video can threaten privacy, especially when it captures telecommuters working at home. We evaluated video blurring, an image masking method long touted to balance privacy and awareness. Results show that video blurring is unable to balance privacy with awareness for risky situations. Reactions by participants suggest that other popular image masking techniques will be problematic as well. The design implication is that image masking techniques will not suffice for privacy protection in video-based telecommuting situations. Other context-aware privacy-protecting strategies are required, as illustrated in our prototype context-aware home media space.
Queueing Network-Model Human Processor (QN-MHP)
Authors: Liu Yili , Feyen Robert , Tsimhoni Omer
Published: July 2006

Queueing Network-Model Human Processor (QN-MHP) is a computational architecture that integrates two complementary approaches to cognitive modeling: the queueing network approach and the symbolic approach (exemplified by the MHP/GOMS family of models, ACT-R, EPIC, and SOAR). Queueing networks are particularly suited for modeling parallel activities and complex structures. Symbolic models have particular strength in generating a person's actions in specific task situations. By integrating the two approaches, QN-MHP offers an architecture for mathematical modeling and real-time generation of concurrent activities in a truly concurrent manner. QN-MHP expands the three discrete serial stages of MHP, of perceptual, cognitive, and motor processing, into three continuous-transmission subnetworks of servers, each performing distinct psychological functions specified with a GOMS-style language. Multitask performance emerges as the behavior of multiple streams of information flowing through a network, with no need to devise complex, task-specific procedures to either interleave production rules into a serial program (ACT-R), or for an executive process to interactively control task processes (EPIC). Using QN-MHP, a driver performance model was created and interfaced with a driving simulator to perform a vehicle steering, and a map reading task concurrently and in real time. The performance data of the model are similar to human subjects performing the same tasks.
Physically large displays improve performance on spatial tasks
Authors: Tan Desney S. , Gergle Darren , Scupelli Peter , Pausch Randy
Published: July 2006

Large wall-sized displays are becoming prevalent. Although researchers have articulated qualitative benefits of group work on large displays, little work has been done to quantify the benefits for individual users. In this article we present four experiments comparing the performance of users working on a large projected wall display to that of users working on a standard desktop monitor. In these experiments, we held the visual angle constant by adjusting the viewing distance to each of the displays. Results from the first two experiments suggest that physically large displays, even when viewed at identical visual angles as smaller ones, help users perform better on mental rotation tasks. We show through the experiments how these results may be attributed, at least in part, to large displays immersing users within the problem space and biasing them into using more efficient cognitive strategies. In the latter two experiments, we extend these results, showing the presence of these effects with more complex tasks, such as 3D navigation and mental map formation and memory. Results further show that the effects of physical display size are independent of other factors that may induce immersion, such as interactivity and mental aids within the virtual environments. We conclude with a general discussion of the findings and possibilities for future work.
Biometric marketing
Authors: Pons Alexander P.
Published: July 2006

How biometric technology can bridge the gap between consumers' needs and marketers' perceptions.
Changing the paradigm of software engineering
Authors: Rajlich Vaclav
Published: July 2006

Software evolution, iterative, and agile development represent a fundamental departure from the previous waterfall-based paradigm of software engineering.
Defining and contributing to software development success
Authors: Procaccino J. Drew , Verner June M. , Lorenzet Steven J.
Published: July 2006

Determining the process-related components affecting software developers' perception of project success.
Tightening access policy
Authors: Huang Eugenia Y.
Published: July 2006

Access policy changes should be handled delicately to avoid damaging visitor loyalty.
Query by humming with the VocalSearch system
Authors: Birmingham William , Dannenberg Roger , Pardo Bryan
Published: July 2006

Don't know the composer, performer, or title? Let the system match the theme you know to the song you want.
Information security standards focus on the existence of process, not its content
Authors: Siponen Mikko
Published: July 2006

The existence of prescribed security processes in organizations does not mean the goals of the processes are achieved.
Message analysis for concurrent programs using message passing
Authors: Carlsson Richard , Sagonas Konstantinos , Wilhelmsson Jesper
Published: July 2006

We describe an analysis-driven storage allocation scheme for concurrent systems that use message passing with copying semantics. The basic principle is that in such a system, data which is not part of any message does not need to be allocated in a shared data area. This allows for the deallocation of thread-specific data without requiring global synchronization and often without even triggering garbage collection. On the other hand, data that is part of a message should preferably be allocated on a shared area since this allows for fast (
O
(1)) interprocess communication that does not require actual copying. In the context of a dynamically typed, higher-order concurrent functional language, we present a static message analysis which guides the allocation. As shown by our performance evaluation, conducted using a production-quality language implementation, the analysis is effective enough to discover most data which is to be used as a message, and to allow the allocation scheme to combine the best performance characteristics of both a process-centric and a communal memory architecture.
Changing Paradigms in Insect Social Evolution: Insights from Halictine and Allodapine Bees
Authors: Schwarz Michael P. , Richards Miriam H. , Danforth Bryan N.
Published: July 2006

Until the 1980s theories of social insect evolution drew strongly on halictine and allodapine bees. However, that early work suffered from a lack of sound phylogenetic inference and detailed information on social behavior in many critical taxa. Recent studies have changed our understanding of these bee groups in profound ways. It has become apparent that forms of social organization, caste determination, and sex allocation are more labile and complex than previously thought, although the terminologies for describing them are still inadequate. Furthermore, the unexpected complexity means that many key parameters in kin selection and reproductive skew models remain unquantified, and addressing this lack of information will be formidable. At the same time, phylogenetic questions have become more tractable, and DNA sequence-based studies have resolved questions that earlier studies could not resolve, radically changing our understanding of the number of origins and losses of sociality in these bees.
Nutritional challenges during development induce sex-specific changes in glucose homeostasis in the adult sheep
Authors: Poore Kirsten R. , Cleal Jane K. , Newman James P. , Boullin Julian P. , Noakes David E. , Hanson Mark A. , Green Lucy R.
Published: July 2006

The early-life environment has implications for risk of adult-onset diseases, such as glucose intolerance, insulin insensitivity, and obesity, effects that may occur with or without reduced birth weight. We determined the consequences of nutrient restriction in early gestation and early postnatal life and their interactions on postnatal growth, body composition, and glucose handling. Ewes received 100% (C, n = 39) or 50% nutritional requirements (U, n = 41) from 1 to 31 days gestation and 100% thereafter. Male and female offspring (singleton/twin) from C and U ewes were then fed either ad libitum (CC n = 22, UC n = 19) or to reduce body weight to 85% of target from 12 to 25 wk of age (CU n = 17, UU n = 22) and ad libitum thereafter. At 1.5 and 2.5 yr, glucose handling was determined by area under the curve (AUC) for glucose and insulin concentrations following intravenous glucose (0.5 g/kg body wt). Insulin sensitivity was determined at 2.5 yr following intravenous insulin (0.5 IU/kg). In females, postnatal undernutrition reduced ( P < 0.05) glucose AUC at both ages, regardless of prenatal nutrition. Postnatal undernutrition did not affect insulin secretion in females but enhanced insulin-induced glucose disappearance in singletons. Poor early postnatal growth was associated with increased fat in females. In males, glucose tolerance was unaffected by undernutrition despite changes in insulin AUC dependent on age, treatment, and single/twin birth. Nutrition in early postnatal life has long-lasting, sex-specific effects on glucose handling in sheep, likely due, in females, to enhanced insulin sensitivity. Improved glucose utilization may aid weight recovery but have negative implications for glucose homeostasis and body composition over the longer term.
Molecular, Functional, and Pathological Aspects of the Mitochondrial ADP/ATP Carrier
Authors: Dahout-Gonzalez C. , Nury H. , Trézéguet V. , Lauquin G. J.-M. , Pebay-Peyroula E. , Brandolin G.
Published: July 2006

In providing the cell with ATP generated by oxidative phosphorylation, the mitochondrial ADP/ATP carrier plays a central role in aerobic eukaryotic cells. Combining biochemical, genetic, and structural approaches contributes to understanding the molecular mechanism of this essential transport system, the dysfunction of which is implicated in neuromuscular diseases.
In Vivo Evidence for Nitric Oxide–Mediated Calcium-Activated Potassium-Channel Activation During Human Endotoxemia
Authors: Pickkers Peter , Dorresteijn Mirrin J. , Bouw; Martijn P.W.J.M. , van der Hoeven Johannes G. , Smits Paul
Published: July 2006

Background—

During septic shock, the vasoconstrictor response to norepinephrine is seriously blunted. Animal experiments suggest that hyperpolarization of smooth muscle cells by opening of potassium (K) channels underlies this phenomenon. In the present study, we examined whether K-channel blockers and/or nitric oxide (NO) synthase inhibition could restore norepinephrine sensitivity during experimental human endotoxemia.

Methods and Results—

Volunteers received 2 ng/kg
Escherichia coli
endotoxin intravenously. Forearm blood flow (FBF) was measured with venous occlusion plethysmography. Infusion of 4 dose steps of norepinephrine into the brachial artery decreased the FBF ratio (ratio of FBF in the experimental arm to FBF in the control arm) to 84±4%, 70±4%, 55±4%, and 38±4% (mean±SEM) of its baseline value. After endotoxin administration, norepinephrine-induced vasoconstriction was attenuated (FBF ratio, 101±4%, 92±4%, 83±6%, and 56±7%; n=30;
P=
0.0018; pooled data). Intrabrachial infusion of the K-channel blocker tetraethylammonium (TEA) completely restored the vasoconstrictor response to norepinephrine from 104±5%, 93±7%, 93±12%, and 69±12% to 89±9%, 73±4%, 59±5%, and 46±8% (n=6;
P
=0.045). Other K-channel blockers did not affect the response to norepinephrine. The NO synthase inhibitor
N
G
-monomethyl-
l
-arginine (L-NMMA; 0.2 mg · min
−1
· dL
−1
intra-arterially) also restored the norepinephrine sensitivity. In the presence of L-NMMA, TEA did not have an additional effect on the norepinephrine-induced vasoconstriction (n=6;
P
=0.9).

Conclusions—

The K-channel blocker TEA restores the attenuated vasoconstrictor response to norepinephrine during experimental human endotoxemia. Coadministration of L-NMMA abolishes this potentiating effect of TEA, suggesting that NO mediates the endotoxin-induced effect on vascular K channels. In the absence of an effect of the selective adenosine triphosphate–dependent K-channel blocker tolbutamide, we conclude that the blunting effect of endotoxin on norepinephrine-induced vasoconstriction is caused by NO-mediated activation of calcium-activated K channels in the vascular wall.
SCN5A
Polymorphism Restores Trafficking of a Brugada Syndrome Mutation on a Separate Gene
Authors: Poelzing Steven , Forleo Cinzia , Samodell Melissa , Dudash Lynn , Sorrentino Sandro , Anaclerio Matteo , Troccoli Rossella , Iacoviello Massimo , Romito Roberta , Guida Pietro , Chahine Mohamed , Pitzalis Mariavittoria , Deschênes Isabelle
Published: July 2006

Background—

Brugada syndrome is associated with a high risk of sudden cardiac death and is caused by mutations in the cardiac voltage-gated sodium channel gene. Previously, the R282H-SCN5A mutation in the sodium channel gene was identified in patients with Brugada syndrome. In a family carrying the R282H-SCN5A mutation, an asymptomatic individual had a common H558R-SCN5A polymorphism and the mutation on separate chromosomes. Therefore, we hypothesized that the polymorphism could rescue the mutation.

Methods and Results—

In heterologous cells, expression of the mutation alone did not produce sodium current. However, coexpressing the mutation with the polymorphism produced significantly greater current than coexpressing the mutant with the wild-type gene, demonstrating that the polymorphism rescues the mutation. Using immunocytochemistry, we demonstrated that the R282H-SCN5A construct can traffic to the cell membrane only in the presence of the H558R-SCN5A polymorphism. Using fluorescence resonance energy transfer and protein fragments centered on H558R-SCN5A, we demonstrated that cardiac sodium channels preferentially interact when the polymorphism is expressed on one protein but not the other.

Conclusions—

This study suggests a mechanism whereby the Brugada syndrome has incomplete penetrance. More importantly, this study suggests that genetic polymorphisms may be a potential target for future therapies aimed at rescuing specific dysfunctional protein channels.
Neutralization of Interleukin-18 Inhibits Neointimal Formation in a Rat Model of Vascular Injury
Authors: Maffia Pasquale , Grassia Gianluca , Di Meglio Paola , Carnuccio Rosa , Berrino Liberato , Garside Paul , Ianaro Angela , Ialenti Armando
Published: July 2006

Background—

Studies in humans and animal models suggest that interleukin-18 (IL-18) plays a crucial role in vascular pathologies. IL-18 is a predictor of cardiovascular death in angina and is involved in atherotic plaque destabilization. Higher IL-18 plasma levels also are associated with restenosis after coronary artery angioplasty performed in patients with acute myocardial infarction. We investigated the effective role of IL-18 in neointimal formation in a balloon-induced rat model of vascular injury.

Methods and Results—

Endothelial denudation of the left carotid artery was performed by use of a balloon embolectomy catheter. Increased expression of IL-18 and IL-18Rα/β mRNA was detectable in carotid arteries from days 2 to 14 after angioplasty. The active form of IL-18 was highly expressed in injured arteries. Strong immunoreactivity for IL-18 was detected in the medial smooth muscle cells at days 2 and 7 after balloon injury and in proliferating/migrating smooth muscle cells in neointima at day 14. Moreover, serum concentrations of IL-18 were significantly higher among rats subjected to vascular injury. Treatment with neutralizing rabbit anti-rat IL-18 immunoglobulin G significantly reduced neointimal formation (by 27%;
P
<0.01), reduced the number of proliferating cells, and inhibited interferon-γ, IL-6, and IL-8 mRNA expression and nuclear factor-κB activation in injured arteries. In addition, in vitro data show that IL-18 affects smooth muscle cell proliferation.

Conclusions—

These results identify a critical role for IL-18 in neointimal formation in a rat model of vascular injury and suggest a potential role for IL-18 neutralization in the reduction of neointimal development.
Effects of Digoxin on Morbidity and Mortality in Diastolic Heart Failure
Authors: Ahmed Ali , Rich Michael W. , Fleg Jerome L. , Zile Michael R. , Young James B. , Kitzman Dalane W. , Love Thomas E. , Aronow Wilbert S. , Adams Kirkwood F. , Gheorghiade Mihai
Published: July 2006

Background—

About half of the 5 million heart failure patients in the United States have diastolic heart failure (clinical heart failure with normal or near-normal ejection fraction). Except for candesartan, no drugs have been tested in randomized clinical trials in these patients. Although digoxin was tested in an appreciable number of diastolic heart failure patients in the Digitalis Investigation Group ancillary trial, detailed findings from this important study have not previously been published.

Methods and Results—

Ambulatory chronic heart failure patients (n=988) with normal sinus rhythm and ejection fraction >45% (median, 53%) from the United States and Canada (1991 to 1993) were randomly assigned to digoxin (n=492) or placebo (n=496). During follow-up with a mean length of 37 months, 102 patients (21%) in the digoxin group and 119 patients (24%) in the placebo group (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.63 to 1.07;
P
=0.136) experienced the primary combined outcome of heart failure hospitalization or heart failure mortality. Digoxin had no effect on all-cause or cause-specific mortality or on all-cause or cardiovascular hospitalization. Use of digoxin was associated with a trend toward a reduction in hospitalizations resulting from worsening heart failure (HR, 0.79; 95% CI, 0.59 to 1.04;
P
=0.094) but also a trend toward an increase in hospitalizations for unstable angina (HR, 1.37; 95% CI, 0.99 to 1.91;
P
=0.061).

Conclusions—

In ambulatory patients with chronic mild to moderate diastolic heart failure and normal sinus rhythm receiving angiotensin-converting enzyme inhibitor and diuretics, digoxin had no effect on natural history end points such as mortality and all-cause or cardiovascular hospitalizations.
Increased Cardiac Adenylyl Cyclase Expression Is Associated With Increased Survival After Myocardial Infarction
Authors: Takahashi Toshiyuki , Tang Tong , Lai N. Chin , Roth David M. , Rebolledo Brian , Saito Miho , Lew Wilbur Y.W. , Clopton Paul , Hammond H. Kirk
Published: July 2006

Background—

Cardiac-directed expression of adenylyl cyclase type VI (AC
VI
) in mice results in structurally normal hearts with normal basal heart rate and function but increased responses to catecholamine stimulation. We tested the hypothesis that increased left ventricular (LV) AC
VI
content would increase mortality after acute myocardial infarction (MI).

Methods and Results—

Transgenic mice with cardiac-directed AC
VI
expression and their transgene-negative littermates (control) underwent coronary ligation, and survival, infarct size, and LV size and function were assessed 1 to 7 days after MI. Mice with increased AC
VI
expression had increased survival (control 41%, AC
VI
74%;
P
=0.004). Infarct size and myocardial apoptotic rates were similar in AC
VI
and control mice; however, AC
VI
mice had less LV dilation (
P
<0.001) and increased ejection fractions (
P<
0.03). Three days after MI, studies in isolated perfused hearts showed that basal LV +dP/dt was similar, but graded dobutamine infusion was associated with a more robust LV contractile response in AC
VI
mice (
P
<0.05). Increased LV function was associated with increases in cAMP generation (
P
=0.0002), phospholamban phosphorylation (
P
<0.04), sarcoplasmic reticulum Ca
2+
-ATPase (SERCA2a) affinity for calcium (
P
<0.015), and reduced AV block (
P
=0.04).

Conclusions—

In acute MI, increased cardiac AC
VI
content attenuates adverse LV remodeling, preserves LV contractile function, and reduces mortality.
A 6-Item Scale for Overall, Emotional, and Social Loneliness
Authors: Gierveld Jenny De Jong , Tilburg Theo Van
Published: July 2006

Loneliness is an indicator of social well-being and pertains to the feeling of missing an intimate relationship (emotional loneliness) or missing a wider social network (social loneliness). The 11-item De Jong Gierveld Loneliness Scale has proved to be a valid and reliable measurement instrument for overall, emotional, and social loneliness, although its length has sometimes rendered it difficult to use in large surveys. In this study, the authors empirically tested a shortened version of the scale on data from two surveys ( N = 9,448). Confirmatory factor analyses confirmed the specification of two latent factors. Congruent validity and the relationship with determinants (partner status, health) proved to be optimal. The 6-item De Jong Gierveld Loneliness Scale is a reliable and valid measurement instrument for overall, emotional, and social loneliness that is suitable for large surveys.
Health policy in Wales: Making a difference in conditions of difficulty
Authors: Drakeford Mark
Published: July 2006

Devolution in a Welsh context has transferred social policy responsibilities to the National Assembly. Health has a dominant presence amongst these responsibilities, both in terms of budget commitment and political salience. This paper explores the context in which Assembly health policy making has taken place, looking at economic, administrative and political dimensions, identifying elements of continuity and change in the Assembly Government's approach to health matters. The paper argues that while policy making has been far-reaching, the implementation of that policy agenda has proved problematic. It concludes that both social policy academics and politicians have underestimated the ways in which barriers to reform can be mobilized, including the way in which health policy debates are presented in the media, even when radicalism has been established in policy intent.
Privatizing education in Scotland? New Labour, modernization and ‘public’ services
Authors: Poole Lynne , Mooney Gerry
Published: July 2006

This paper focuses primarily on New Labour's public services ‘modernization’ agenda, raising questions about recent shifts in governance, local government finance and the relationship between the commercial sector and the provision of welfare. It argues that this agenda is being embraced by the Scottish Executive through its commitment to Public– Private Partnerships (PPPs) and an increased role for market-based solutions to the problem of poorly performing public services. It examines PPPs in an education context by focusing principally on the experience in Glasgow and argues that PPPs in education and elsewhere in the public sector are part of a broader New Labour agenda to present itself as the ‘party of business’, in Scotland as well as in England, and in spite of the potential for policy divergence opened up by the devolution process. This paper locates PPPs in the context of other privatization- type reforms and explores New Labour's ideological commitment to opening up public services across Britain to market forces in the context of the General Agreement on Trade in Services (GATS).
Devolving the heartland: Making up a new social policy for the ‘South East’
Authors: Cochrane Allan
Published: July 2006

Devolution appears to challenge the traditional regional and national hierarchies of the UK, but in practice the dominance of the South East of England has been maintained through active state intervention. As social welfare has increasingly been redefined through economic success and access to the labour market, the focus of social policy has shifted accordingly. In this context the South East has been re-imagined not as a symbol of inequality and a potential source of redistribution, but rather as driver of economic prosperity and ‘national’ (UK) well-being.
The Development of Shared Stereotypic Impressions in Conversation
Authors: Ruscher Janet B. , Hammer Elliott D.
Published: July 2006

The authors’ research over the past 10 years has examined how dyads work together to find a common ground understanding through which to develop a shared impression. This article begins by examining the extant motivations underlying such efforts and presents a model of why and under what conditions shared stereotypic impressions develop. The article then turns to the mechanisms through which these shared stereotypic impressions develop through conversation, with a particular eye to the relation between dyads’ language choices and their resulting impressions. Finally, the article addresses a serious limitation of the authors’ work, namely, the authors’ primary focus on dyads comprising individuals who share a common group identity such as gender or ethnicity. Working within their model framework, the authors discuss the unique challenges of shared impression formation facing dyads who comprise individuals from dissimilar groups.
Politics within paths: trajectories of Danish and Swedish earnings-related pensions
Authors: Green-Pedersen Christoffer , Lindbom Anders
Published: July 2006

This article investigates earnings-related pension schemes in Denmark and Sweden with a focus on the last two decades. It takes the path dependency idea as its starting point and develops it further with regard to pension politics. In the Danish case, the article shows that existing funded, occupational pension schemes precluded a pay-as-you-go (PAYGO) solution for workers not already covered due to a ‘reverse double payment problem’. Political attention centred instead on broadening the coverage of occupational schemes. The article demonstrates that the development of funded pension systems also shows a great deal of path dependency. In the Swedish case, we provide a detailed empirical investigation which shows how the double payment problem affects the positions of political parties, rather than the entire reform process. The study thus argues that the political parties were the crucial actors in the Swedish pension reform and that the path dependency facilitated a consensual reform process because it made irrelevant a more fundamental party political disagreement over the pension system.