bluuebunny/crossref_metadata_2025 huggingface dataset:
Perception of complex aggregates
Authors: Ramanarayanan Ganesh , Bala Kavita , Ferwerda James A.
Published: August 2008

Aggregates of individual objects, such as forests, crowds, and piles of fruit, are a common source of complexity in computer graphics scenes. When viewing an aggregate, observers attend less to individual objects and focus more on overall properties such as numerosity, variety, and arrangement. Paradoxically, rendering and modeling costs increase with aggregate complexity, exactly when observers are attending less to individual objects.

In this paper we take some first steps to characterize the limits of visual coding of aggregates to efficiently represent their appearance in scenes. We describe psychophysical experiments that explore the roles played by the geometric and material properties of individual objects in observers' abilities to discriminate different aggregate collections. Based on these experiments we derive metrics to predict when two aggregates have the same appearance, even when composed of different objects. In a follow-up experiment we confirm that these metrics can be used to predict the appearance of a range of realistic aggregates. Finally, as a proof-of-concept we show how these new aggregate perception metrics can be applied to simplify scenes by allowing substitution of geometrically simpler aggregates for more complex ones without changing appearance.
Self-animating images
Authors: Chi Ming-Te , Lee Tong-Yee , Qu Yingge , Wong Tien-Tsin
Published: August 2008

Illusory motion in a still image is a fascinating research topic in the study of human motion perception. Physiologists and psychologists have attempted to understand this phenomenon by constructing simple, color repeated asymmetric patterns (RAP) and have found several useful rules to enhance the strength of illusory motion. Based on their knowledge, we propose a computational method to generate self-animating images. First, we present an optimized RAP placement on streamlines to generate illusory motion for a given static vector field. Next, a general coloring scheme for RAP is proposed to render streamlines. Furthermore, to enhance the strength of illusion and respect the shape of the region, a smooth vector field with opposite directional flow is automatically generated given an input image. Examples generated by our method are shown as evidence of the illusory effect and the potential applications for entertainment and design purposes.
A mass spring model for hair simulation
Authors: Selle Andrew , Lentine Michael , Fedkiw Ronald
Published: August 2008

Our goal is to simulate the full hair geometry, consisting of approximately one hundred thousand hairs on a typical human head. This will require scalable methods that can simulate every hair as opposed to only a few guide hairs. Novel to this approach is that the individual hair/hair interactions can be modeled with physical parameters (friction, static attraction, etc.) at the scale of a single hair as opposed to clumped or continuum interactions. In this vein, we first propose a new altitude spring model for preventing collapse in the simulation of volumetric tetrahedra, and we show that it is also applicable both to bending in cloth and torsion in hair. We demonstrate that this new torsion model for hair behaves in a fashion similar to more sophisticated models with significantly reduced computational cost. For added efficiency, we introduce a semi-implicit discretization of standard springs that makes them truly linear in multiple spatial dimensions and thus unconditionally stable without requiring Newton-Raphson iteration. We also simulate complex hair/hair interactions including sticking and clumping behavior, collisions with objects (e.g. head and shoulders) and self-collisions. Notably, in line with our goal to simulate the full head of hair, we do not generate any new hairs at render time.
Light mixture estimation for spatially varying white balance
Authors: Hsu Eugene , Mertens Tom , Paris Sylvain , Avidan Shai , Durand Frédo
Published: August 2008

White balance is a crucial step in the photographic pipeline. It ensures the proper rendition of images by eliminating color casts due to differing illuminants. Digital cameras and editing programs provide white balance tools that assume a single type of light per image, such as daylight. However, many photos are taken under mixed lighting. We propose a white balance technique for scenes with two light types that are specified by the user. This covers many typical situations involving indoor/outdoor or flash/ambient light mixtures. Since we work from a single image, the problem is highly underconstrained. Our method recovers a set of dominant material colors which allows us to estimate the local intensity mixture of the two light types. Using this mixture, we can neutralize the light colors and render visually pleasing images. Our method can also be used to achieve post-exposure relighting effects.
Structure-aware halftoning
Authors: Pang Wai-Man , Qu Yingge , Wong Tien-Tsin , Cohen-Or Daniel , Heng Pheng-Ann
Published: August 2008

This paper presents an optimization-based halftoning technique that preserves the structure and tone similarities between the original and the halftone images. By optimizing an objective function consisting of both the structure and the tone metrics, the generated halftone images preserve visually sensitive texture details as well as the local tone. It possesses the blue-noise property and does not introduce annoying patterns. Unlike the existing edge-enhancement halftoning, the proposed method does not suffer from the deficiencies of edge detector. Our method is tested on various types of images. In multiple experiments and the user study, our method consistently obtains the best scores among all tested methods.
Automatic generation of tourist maps
Authors: Grabler Floraine , Agrawala Maneesh , Sumner Robert W. , Pauly Mark
Published: August 2008

Tourist maps are essential resources for visitors to an unfamiliar city because they visually highlight landmarks and other points of interest. Yet, hand-designed maps are static representations that cannot adapt to the needs and tastes of the individual tourist. In this paper we present an automated system for designing tourist maps that selects and highlights the information that is most important to tourists. Our system determines the salience of map elements using bottom-up vision-based image analysis and top-down web-based information extraction techniques. It then generates a map that emphasizes the most important elements, using a combination of multiperspective rendering to increase visibility of streets and landmarks, and cartographic generalization techniques such as simplification, deformation, and displacement to emphasize landmarks and de-emphasize less important buildings. We show a number of automatically generated tourist maps of San Francisco and compare them to existing automated and manual approaches.
Using prototypes in early pervasive game development
Authors: Ollila Elina M. I. , Suomela Riku , Holopainen Jussi
Published: August 2008

In this article we discuss various prototyping methods in early pervasive game development. The focus is on pervasive games that are played with mobile phones. Choosing the right prototyping method is crucial in achieving results that can be used for validating or developing further design ideas. In this article we give guidelines that help the selection process and give ideas on methods that can be used in different situations.

We have play-tested pervasive game prototypes using agile software prototype development methods, forum prototypes, and guided paper prototyping methods. We give examples of five pervasive games where these kinds of prototyping methods are used. In concluding, we compare the results and discuss their benefits and disadvantages in the game development process, that is, when the methods should be used and what should be considered when using them.
Character play
Authors: Tychsen Anders , Hitchens Michael , Brolund Thea
Published: August 2008

Avatars are a commonly used mechanism for representing the player within the world of a game. The avatar forms the main point of interaction between the player and the game, and thus the avatar is an important game design feature. Character-based games combine the concept of an avatar with that of a character, enhancing the avatar with specific features that commonly are changeable, and which can be defined within or outside the framework of the game rules. Within digital games, the rules-based features have received comparatively more attention than, for example, the personalities and background histories of game characters. This article presents results from a comprehensive empirical study of the way complex game characters are utilized by players in multiplayer role-playing games across two different media platforms. The results indicate that adult players are capable of comprehending and utilizing game characters with well-defined personalities and backgrounds, as well as rules-based components. Furthermore, that the game format plays a significant role in the pattern of usage of the character elements. This pattern appears directly linked with variations in the way that the different game formats handle player characters and activate or promote the activation of, different forms of character elements. The degree to which different character elements are activated also has implications for the degree of player engagement in the character.
From the prototype to the final embedded system using the Ocarina AADL tool suite
Authors: Hugues Jerome , Zalila Bechir , Pautet Laurent , Kordon Fabrice
Published: August 2008

Building distributed deal-time embedded systems requires a stringent methodology, from early requirement capture to full implementation. However, there is a strong link between the requirements and the final implementation (e.g., scheduling and resource dimensioning). Therefore, a rapid prototyping process based on automation of tedious and error-prone tasks (analysis and code generation) is required to speed up the development cycle. In this article, we show how the AADL (
Architecture Analysis and Design Language
), which appeared in late 2004, helps solve these issues thanks to a dedicated tool suite. We then detail the prototyping process and its current implementation: Ocarina.
Types for atomicity
Authors: Flanagan Cormac , Freund Stephen N. , Lifshin Marina , Qadeer Shaz
Published: August 2008

Atomicity is a fundamental correctness property in multithreaded programs. A method is atomic if, for every execution, there is an equivalent serial execution in which the actions of the method are not interleaved with actions of other threads. Atomic methods are amenable to sequential reasoning, which significantly facilitates subsequent analysis and verification.

This article presents a type system for specifying and verifying the atomicity of methods in multithreaded Java programs using a synthesis of Lipton's theory of reduction and type systems for race detection. The type system supports guarded, write-guarded, and unguarded fields, as well as thread-local data, parameterized classes and methods, and protected locks. We also present an algorithm for verifying atomicity via type inference.

We have applied our type checker and type inference tools to a number of commonly used Java library classes and programs. These tools were able to verify the vast majority of methods in these benchmarks as atomic, indicating that atomicity is a widespread methodology for multithreaded programming. In addition, reported atomicity violations revealed some subtle errors in the synchronization disciplines of these programs.
Local reasoning about a copying garbage collector
Authors: Torp-Smith Noah , Birkedal Lars , Reynolds John C.
Published: August 2008

We present a programming language, model, and logic appropriate for implementing and reasoning about a memory management system. We state semantically what is meant by correctness of a copying garbage collector, and employ a variant of the novel separation logics to formally specify partial correctness of Cheney's copying garbage collector in our program logic. Finally, we prove that our implementation of Cheney's algorithm meets its specification using the logic we have given and auxiliary variables.
Evaluation of Intrusion Detection Systems Under a Resource Constraint
Authors: Ryu Young U. , Rhee Hyeun-Suk
Published: August 2008

An intrusion detection system plays an important role in a firm's overall security protection. Its main purpose is to identify potentially intrusive events and alert the security personnel to the danger. A typical intrusion detection system, however, is known to be imperfect in detection of intrusive events, resulting in high false-alarm rates. Nevertheless, current intrusion detection models unreasonably assume that upon alerts raised by a system, an information security officer responds to all alarms without any delay and avoids damages of hostile activities. This assumption of responding to all alarms with no time lag is often impracticable. As a result, the benefit of an intrusion detection system can be overestimated by current intrusion detection models. In this article, we extend previous models by including an information security officer's alarm inspection under a constraint as a part of the process in determining the optimal intrusion detection policy. Given a potentially hostile environment for a firm, in which the intrusion rates and costs associated with intrusion and security officers' inspection can be estimated, we outline a framework to establish the optimal operating points for intrusion detection systems under security officers' inspection constraint. The optimal solution to the model will provide not only a basis of better evaluation of intrusion detection systems but also useful insights into operations of intrusion detection systems. The firm can estimate expected benefits for running intrusion detection systems and establish a basis for increase in security personnel to relax security officers' inspection constraint.
Using First-Order Logic to Reason about Policies
Authors: Halpern Joseph Y. , Weissman Vicky
Published: August 2008

A policy describes the conditions under which an action is permitted or forbidden. We show that a fragment of (multi-sorted) first-order logic can be used to represent and reason about policies. Because we use first-order logic, policies have a clear syntax and semantics. We show that further restricting the fragment results in a language that is still quite expressive yet is also tractable. More precisely, questions about entailment, such as “May Alice access the file?”, can be answered in time that is a low-order polynomial (indeed, almost linear in some cases), as can questions about the consistency of policy sets.
A Comprehensive Memory Modeling Tool and Its Application to the Design and Analysis of Future Memory Hierarchies
Authors: Thoziyoor Shyamkumar , Ahn Jung Ho , Monchiero Matteo , Brockman Jay B. , Jouppi Norman P.
Published: August 2008

In this paper we introduce CACTI-D, a significant enhancement of CACTI 5.0. CACTI-D adds support for modeling of commodity DRAM technology and support for main memory DRAM chip organization. CACTI-D enables modeling of the complete memory hierarchy with consistent models all the way from SRAM based L1 caches through main memory DRAMs on DIMMs. We illustrate the potential applicability of CACTI-D in the design and analysis of future memory hierarchies by carrying out a last level cache study for a multicore multithreaded architecture at the 32nm technology node. In this study we use CACTI-D to model all components of the memory hierarchy including L1, L2, last level SRAM, logic process based DRAM or commodity DRAM L3 caches, and main memory DRAM chips. We carry out architectural simulation using benchmarks with large data sets and present results of their execution time, breakdown of power in the memory hierarchy, and system energy-delay product for the different system configurations. We find that commodity DRAM technology is most attractive for stacked last level caches, with significantly lower energy-delay products.
Parallelism-Aware Batch Scheduling
Authors: Mutlu Onur , Moscibroda Thomas
Published: August 2008

In a chip-multiprocessor (CMP) system, the DRAM system isshared among cores. In a shared DRAM system, requests from athread can not only delay requests from other threads by causingbank/bus/row-buffer conflicts but they can also destroy other threads’DRAM-bank-level parallelism. Requests whose latencies would otherwisehave been overlapped could effectively become serialized. As aresult both fairness and system throughput degrade, and some threadscan starve for long time periods.This paper proposes a fundamentally new approach to designinga shared DRAM controller that provides quality of service to threads,while also improving system throughput. Our parallelism-aware batchscheduler (PAR-BS) design is based on two key ideas. First, PARBSprocesses DRAM requests in batches to provide fairness and toavoid starvation of requests. Second, to optimize system throughput,PAR-BS employs a parallelism-aware DRAM scheduling policythat aims to process requests from a thread in parallel in the DRAMbanks, thereby reducing the memory-related stall-time experienced bythe thread. PAR-BS seamlessly incorporates support for system-levelthread priorities and can provide different service levels, includingpurely opportunistic service, to threads with different priorities.We evaluate the design trade-offs involved in PAR-BS and compareit to four previously proposed DRAM scheduler designs on 4-, 8-, and16-core systems. Our evaluations show that, averaged over 100 4-coreworkloads, PAR-BS improves fairness by 1.11X and system throughputby 8.3% compared to the best previous scheduling technique, Stall-Time Fair Memory (STFM) scheduling. Based on simple request prioritizationrules, PAR-BS is also simpler to implement than STFM.
iDEAL
Authors: Kodi Avinash Karanth , Sarathy Ashwini , Louri Ahmed
Published: August 2008

Network-on-Chip (NoC) architectures have been adopted by a growing number of multi-core designs as a flexible and scalable solution to the increasing wire delay constraints in the deep sub-micron regime. However, the shrinking feature size limits the performance of NoCs due to power and area constraints. Research into the optimization of NoCs has shown that a reduction in the number of buffers in the NoC routers reduces the power and area overhead but degrades the network performance. In this paper, we propose iDEAL, a low-power area-efficient NoC architecture by reducing the number of buffers within the router. To overcome the performance degradation caused by the reduced buffer size, we propose to use adaptive dual-function links capable of data transmission as well as data storage when required. Simulation results for the proposed architecture show that reducing the router buffer size in half and using the adaptive dual-function links achieves nearly 40% savings in buffer power, 30% savings in overall network power and about 41% savings in the router area, with only a marginal 1-3% drop in performance. Moreover, the performance in iDEAL can be further improved by aggressive and speculative flow control techniques.
Fetch-Criticality Reduction through Control Independence
Authors: Agarwal Mayank , Navale Nitin , Malik Kshitiz , Frank Matthew I.
Published: August 2008

Architectures that exploit control independence (CI) promise to remove in-order fetch bottlenecks, like branch mispredicts, instruction-cache misses and fetch unit stalls, from the critical path of single-threaded execution. By exposing more fetch options, however, CI architectures also expose more performance tradeoffs. These tradeoffs make it hard to design policies that deliver good performance.This paper presents a criticality-based model for reasoning about CI architectures, and uses that model to describe the tradeoffs between gains from control independence versus increased costs of honoring data dependences. The model is then used to derive the design of a criticality-aware task selection policy that strikes the right balance between fetch-criticality and execute-criticality. Finally, the papervalidates the model by attacking branch-misprediction induced fetch-criticality through the above derived spawnpolicy. This leads to as high as 100% improvements in performance, and in the region of 40% or more improvements for four of the benchmarks where this is the main problem. Criticality analysis shows that this improvement arises due to reduced fetch-criticality.
Towards human competitive driving of scale model of a car
Authors: Tanev Ivan , Shimohara Katsunori
Published: August 2008

The success of the computer playing board games (e.g., chess [8], checkers [4], backgammon, tic-tac-toe, etc.) has long served as an indication of the progress in the field of artificial intelligence (AI). The expanding scope of applicability of AI, when the latter is employed to control the individual characters (agents) which are able to "learn" the environment, often including opponents, and to adopt an adaptive optimal (rather than a priori preprogrammed) playing tactics and strategy include soccer [15], motocross and car racing [3, 21], etc. [4], [6]. In this article, we focus on the domain of car racing, and consider the problem of designing a driving agent, able to remotely control a scale model of a racing car, which runs in a human-competitive, fast and consistent way. Adhering to the commonly recognized criteria of the human competitiveness of automatically evolved solutions, we attempt to verify that the evolved driving agent "holds its own or wins a regulated competition involving human contestants" [11].
Inhalation Induced Stresses and Flow Characteristics in Human Airways through Fluid‐Structure Interaction Analysis
Authors: Koombua Kittisak , Pidaparti Ramana M.
Published: August 2008

Better understanding of stresses and flow characteristics in the human airways is very important for many clinical applications such as aerosol drug therapy, inhalation toxicology, and airway remodeling process. The bifurcation geometry of airway generations 3 to 5 based on the ICRP tracheobronchial model was chosen to analyze the flow characteristics and stresses during inhalation. A computational model was developed to investigate the airway tissue flexibility effect on stresses and flow characteristics in the airways. The finite‐element method with the fluid‐structure interaction analysis was employed to investigate the transient responses of the flow characteristics and stresses in the airways during inhalation. The simulation results showed that tissue flexibility affected the maximum airflow velocity, airway pressure, and wall shear stress about 2%, 7%, and 6%, respectively. The simulation results also showed that the differences between the orthotropic and isotropic material models on the airway stresses were in the ranges of 25–52%. The results from the present study suggest that it is very important to incorporate the orthotropic tissue properties into a computational model for studying flow characteristics and stresses in the airways.
Scattering‐Based Model of the SAR Signatures of Complex Targets for Classification Applications
Authors: Margarit Gerard , Mallorqui Jordi J.
Published: August 2008

The modeling of complex target response in SAR imagery is the main subject of this paper. The analysis of a large database of SAR images with polarimetric and interferometric capabilities is used to accurately establish how the different structural parts of targets interact with the incident signal. This allows to relate the reflectivity information provided by SAR images with specific geometries and to fix variation reflectivity patterns in terms of different imaging parameters such as image resolution, incidence angle, or operating frequency. Most of the used images have been obtained from the SAR simulator of complex targets developed at UPC, which is able to generate realistic data for a wide range of observation and environmental conditions. The result is a precise scattering‐based SAR model that opens the door, among others, to an alternative way for reliable geometry retrieval. Under this approach, a novel SAR classification method for ships has been proposed. The preliminary evaluation in simulated scenarios shows a notable classification capability even under strong clutter and ship motion conditions. Due to these promising results, the same methodology is intended to be applied to urban areas. Concerns about possible model limitations and required improvements are preliminarily treated.
Noncoherence of a Causal Wiener Algebra Used in Control Theory
Authors: Sasane Amol
Published: August 2008

Let ℂ≥0 : = {s ∈ ℂ | Re (s) ≥ 0}, and let 𝒲+ denote the ring of all functions
f : ℂ≥0→ℂ
such that  (s ∈ ℂ≥0), where , and
 0 = t0 < t1 < t2 < ⋯ equipped with pointwise operations. (Here denotes the Laplace transform.) It is shown that the ring 𝒲+ is not coherent, answering a question of Alban Quadrat. In fact, we present two principal ideals in the domain 𝒲+ whose intersection is not finitely generated.
Hollow Cathode and Low-Thrust Extraction Grid Analysis for a
Miniature Ion Thruster
Authors: Wirz Richard , Sullivan Regina , Przybylowski JoHanna , Silva Mike
Published: August 2008

Miniature ion thrusters are well suited for future space missions that
require high efficiency, precision thrust, and low contamination in the mN to
sub-mN range. JPL's miniature xenon Ion (MiXI) thruster has demonstrated an
efficient discharge and ion extraction grid assembly using filament cathodes
and the internal conduction (IC) cathode. JPL is currently preparing to incorporate a miniature
hollow cathode for the MiXI discharge. Computational analyses anticipate that an axially
upstream hollow cathode location provides the most favorable performance and beam
profile; however, the hot surfaces of the hollow cathode must be sufficiently downstream
to avoid demagnetization of the cathode magnet at the back of the chamber, which can
significantly reduce discharge performance. MiXI's ion extraction grids are
designed to provide >3 mN of thrust; however, previous to this effort, the low-thrust
characteristics had not been investigated. Experimental results obtained with the
MiXI-II thruster (a near replica or the original MiXI thruster) show that sparse average
discharge plasma densities of ∼5×1015–5×1016 m-3 allow the use of very low
beamlet focusing extraction voltages of only ∼250–500 V, thus providing thrust levels
as low as 0.03 mN for focused beamlet conditions. Consequently, the thrust range
thus far demonstrated by MiXI in this and other tests is 0.03–1.54 mN.
Transtelephonic Home Blood Pressure to Assess the Monoamine Oxidase-B Inhibitor Rasagiline in Parkinson Disease
Authors: White William B. , Salzman Phyllis , Schwid Steven R.
Published: August 2008

Monoamine oxidase inhibitors are associated with dietary tyramine interactions that can induce hypertensive crises. Rasagiline mesylate is a novel irreversible selective monoamine oxidase type B inhibitor for Parkinson disease that may have a low risk of interaction with dietary tyramine because of its selectivity. To study interactions of rasagiline with diets unrestricted in tyramine-containing foods, we incorporated transtelephonic, self-monitoring of the blood pressure (BP) into a randomized, placebo-controlled trial of rasagiline 0.5 and 1.0 mg daily in 414 levodopa-treated Parkinson patients with motor fluctuations. The proportion of patients with a systolic BP increase of >30 mm Hg was the primary BP end point. In 13 968 self-measured readings at baseline, the proportion of systolic BP values that increased by >30 mm Hg after a meal ranged from 9.5% to 12.9% in the 3 treatment groups. In 25 733 BPs obtained postrandomization, the proportion of values with a >30-mm Hg systolic postprandial increase was 15% in the placebo group, 15% in the rasagiline 0.5-mg group, and 11% in the rasagiline 1-mg group after 3 weeks of double-blind therapy and 13%, 14%, and 12%, respectively, after 26 weeks of treatment (
P
value was not significant for all of the comparisons among treatment groups). A postprandial increase in systolic BP to >180 mm Hg at any time after randomization was seen in 3.3%, 2.6%, and 2.9% of the placebo, 0.5-mg, and 1.0-mg rasagiline groups, respectively. These data demonstrate that rasagiline did not induce postprandial hypertension in patients with Parkinson disease who were on an unrestricted diet.
Sexual Assault in Prison and Beyond
Authors: Blackburn Ashley G. , Mullings Janet L. , Marquart James W.
Published: August 2008

Although several studies have examined consensual sexual activity in female correctional institutions, there has been little research conducted on in-prison sexual assault among incarcerated females. The present study examines 436 female inmates in a large Southern prison system and explores demographic characteristics as predictors of sexual victimization. Of the women in the sample, 68.4% reported lifetime sexual victimization, and 17.2% reported in-prison sexual victimization. Consistent with previous research, 3.0% of the entire sample reported being the victim of a completed prison rape. Significant demographic predictors were revealed for lifetime sexual victimization but not for in-prison sexual victimization. Implications for correctional policy based on research findings are discussed.
Evaluating the Efficacy of a Parenting Program for Incarcerated Mothers
Authors: Sandifer Jacquelyn L.
Published: August 2008

Life course theory supports strengthening incarcerated mothers' parenting skills and parent–child relationships to help both inmate mothers and their children. Prison parenting programs address this need. This study evaluates the efficacy of the parenting program at a Southern correctional institution for women in changing inmate mothers' parenting knowledge and skills. A pretest–posttest nonequivalent comparison group quasi-experimental design was used to assess short-term change in knowledge after 12-week parent education courses. Paired sample t tests of parenting class participants' ( n = 64) Time 1 and Time 2 scores on two parenting inventories suggest significant positive change likely resulting from the parent education program. No significant change was indicated in a comparison group ( n = 26) of inmate mothers.
The Mini Nutritional Assessment®—Its History, Today's Practice, and Future Perspectives
Authors: Bauer Juergen M. , Kaiser Matthias J. , Anthony Patricia , Guigoz Yves , Sieber Cornel C.
Published: August 2008

In the early 1990s, the Mini Nutritional Assessment® (MNA; Nestle Nutrition, Vevey, Switzerland) was developed for nutrition screening in the elderly. Since then, it became the most established and widespread screening tool for older persons and has been translated into many different languages. The MNA shows prognostic relevance with regard to functionality, morbidity, and mortality of the elderly in different settings. This article recalls the development of the MNA with its short form (MNA‐SF) and reviews the literature, focusing on the most recent publications. Specific features of the application of the MNA in different settings (community, nursing home, hospital) are considered. Minor shortcomings of the tool, such as the resources and the cooperation necessary for completion of the MNA, are discussed. Future options for the adaptation of this valuable tool are briefly characterized.
Comment on:  Early Enteral Supplementation With Key Pharmaconutrients Improves Sequential Organ Failure Assessment Score in Critically Ill Patients With Sepsis: Outcome of a Randomized, Controlled, Double‐Blind Trial
Authors: Koretz Ronald L.
Published: August 2008

Objective: To assess the safety and efficacy of an early enteral pharmaconutrition supplement containing glutamine dipeptides, antioxidative vitamins and trace elements, and butyrate in critically ill, septic patients. Design: A prospective, randomized, controlled, double‐blind clinical trial. Setting: Adult intensive care unit in a university hospital. Patients: Fifty‐five critically ill, septic patients requiring enteral feeding. Interventions: Patients received either an enteral supplement (500 ml of Intestamin, Fresenius Kabi) containing conditionally essential nutrients or a control solution via the nasogastric route for up to 10 days. Inclusion occurred within 24 hours of intensive care unit admission. Additionally, patients received enteral feeding with an immunonutrition formula (experimental group) or standard formula (control group) initiated within 48 hours after enrollment. Measurements and main results: Organ dysfunction was assessed by daily total Sequential Organ Failure Assessment (SOFA) score over the 10‐day study period in both patient groups. Patients receiving the experimental supplement showed a significantly faster decline in the regression slopes of delta daily total SOFA score over time compared with control. The difference between the regression coefficients of the 2 slopes was significant irrespective of the level of analysis: intent to treat –0.32 vs –0.14, P < .0001; per protocol– 0.34 vs –0.14, P < .0001; and completers (patients receiving ≥80% of the calculated caloric target over a period of 6 days)– 0.26 vs –0.16, P = .0005. Vitamin C, as a marker of supplement absorption, increased from 10.6 (1.9‐159.4) μmol/L (normal range 20‐50 μmol/L) on day 1 to 58.7 (5.4‐189.9) μmol/L by day 3 (P = .002) in the intervention group but remained below the normal range in the control group 17.0 (2.8‐78.5) on day 1 and 14.3 (2.4‐179.6) on day 3. Serum levels of glycine, serine, arginine, ornithine, vitamin E, and β‐carotene all increased significantly with treatment in the supplementation group. Conclusions: In medical patients with sepsis, early enteral pharmaconutrition with glutamine dipeptides, vitamin C and E, β‐carotene, selenium, zinc, and butyrate in combination with an immunonutrition formula results in significantly faster recovery of organ function compared with control.
Training Adult Protective Services Workers About Domestic Violence
Authors: Payne Brian K.
Published: August 2008

Many cases of elder abuse involve instances of partner abuse. In this study, attention is given to whether adult protective services supervisors think their workers know enough about specific aspects of domestic violence. Attention is also given to the strategies that the supervisors think would be most useful to teach about domestic violence. According to the supervisors, workers need to know more about intervening with perpetrators, planning for their own safety, and dealing with frustrations. The supervisors rated the importance of understanding theoretical perspectives as low. Results also show that agencies with domestic violence training policies participate in domestic violence training programs more often.
Using a Discrete Choice Model to Identify Consumer Meal Preferences Within a Prix Fixe Menu
Authors: Myung Eunha , Hale Feinstein Andrew , McCool Audrey C.
Published: August 2008

Previous research has shown that consumers form perceptions of value when buying a bundle through the comparison of a bundle price to the sum of associated individual prices. The perceptions of value are then directly related to preference or choice. Using a prix fixe menu as a bundle exemplar, the above notion of value perception was empirically tested by investigating whether consumers were more likely to choose higher priced á la carte items to be included in their bundles when given an opportunity to choose between various prix fixe menus. The study finds that price differences among á la carte items indeed influenced consumers' choice decisions when selecting a prix fixe menu; consumers attached more importance to the higher priced appetizer and entrée items than the lower priced ones.
Training Police Leadership to Recognize and Address Operational Stress
Authors: Chapin Mark , Brannen Stephen J. , Singer Mark I. , Walker Michael
Published: August 2008

A community-based agency developed training for Cleveland Police Department Lieutenants and Supervisory Sergeants. This training adapted current methods used by the U.S. Army to deal with military combat stress. Police leaders were trained to recognize signs of operational stress in their line officers and provide “Leader Actions” to minimize long-term sequelae of operational stress, such as posttraumatic stress disorder, absenteeism, resignation, and misconduct. Laminated pocket cards were provided which summarized warning signs of operational stress, self-care and partner-care actions, and leader strategies to treat early signs of operational stress. Based on focus groups with police supervisors, an incentive system was developed and implemented to reward officers seeking help or assisting other officers in managing operational stress, which could change the culture of keeping silent about problems and remove the stigma attached to help seeking. Eighty-three police supervisors have been trained, with plans to provide further training to district (precinct) commanders.
Evaluation of genomic island predictors using a comparative genomics approach
Authors: Langille Morgan GI , Hsiao William WL , Brinkman Fiona SL
Published: August 2008

Background

Genomic islands (GIs) are clusters of genes in prokaryotic genomes of probable horizontal origin. GIs are disproportionately associated with microbial adaptations of medical or environmental interest. Recently, multiple programs for automated detection of GIs have been developed that utilize sequence composition characteristics, such as G+C ratio and dinucleotide bias. To robustly evaluate the accuracy of such methods, we propose that a dataset of GIs be constructed using criteria that are independent of sequence composition-based analysis approaches.

Results

We developed a comparative genomics approach (IslandPick) that identifies both very probable islands and non-island regions. The approach involves 1) flexible, automated selection of comparative genomes for each query genome, using a distance function that picks appropriate genomes for identification of GIs, 2) identification of regions unique to the query genome, compared with the chosen genomes (positive dataset) and 3) identification of regions conserved across all genomes (negative dataset). Using our constructed datasets, we investigated the accuracy of several sequence composition-based GI prediction tools.

Conclusion

Our results indicate that AlienHunter has the highest recall, but the lowest measured precision, while SIGI-HMM is the most precise method. SIGI-HMM and IslandPath/DIMOB have comparable overall highest accuracy. Our comparative genomics approach, IslandPick, was the most accurate, compared with a curated list of GIs, indicating that we have constructed suitable datasets. This represents the first evaluation, using diverse and, independent datasets that were not artificially constructed, of the accuracy of several sequence composition-based GI predictors. The caveats associated with this analysis and proposals for optimal island prediction are discussed.
Can modeling of HIV treatment processes improve outcomes? Capitalizing on an operations research approach to the global pandemic
Authors: Xiong Wei , Hupert Nathaniel , Hollingsworth Eric B , O'Brien Megan E , Fast Jessica , Rodriguez William R
Published: August 2008

Background

Mathematical modeling has been applied to a range of policy-level decisions on resource allocation for HIV care and treatment. We describe the application of classic operations research (OR) techniques to address logistical and resource management challenges in HIV treatment scale-up activities in resource-limited countries.

Methods

We review and categorize several of the major logistical and operational problems encountered over the last decade in the global scale-up of HIV care and antiretroviral treatment for people with AIDS. While there are unique features of HIV care and treatment that pose significant challenges to effective modeling and service improvement, we identify several analogous OR-based solutions that have been developed in the service, industrial, and health sectors.

Results

HIV treatment scale-up includes many processes that are amenable to mathematical and simulation modeling, including forecasting future demand for services; locating and sizing facilities for maximal efficiency; and determining optimal staffing levels at clinical centers. Optimization of clinical and logistical processes through modeling may improve outcomes, but successful OR-based interventions will require contextualization of response strategies, including appreciation of both existing health care systems and limitations in local health workforces.

Conclusion

The modeling techniques developed in the engineering field of operations research have wide potential application to the variety of logistical problems encountered in HIV treatment scale-up in resource-limited settings. Increasing the number of cross-disciplinary collaborations between engineering and public health will help speed the appropriate development and application of these tools.
First detection, isolation and molecular characterization of infectious salmon anaemia virus associated with clinical disease in farmed Atlantic salmon (Salmo salar) in Chile
Authors: Godoy Marcos G , Aedo Alejandra , Kibenge Molly JT , Groman David B , Yason Carmencita V , Grothusen Horts , Lisperguer Angelica , Calbucura Marlene , Avendaño Fernando , Imilán Marcelo , Jarpa Miguel , Kibenge Frederick SB
Published: August 2008

Background

Infectious salmon anaemia (ISA) is a viral disease of marine-farmed Atlantic salmon (Salmo salar) caused by ISA virus (ISAV), which belongs to the genus Isavirus, family Orthomyxoviridae. The virus is considered to be carried by marine wild fish and for over 25 years has caused major disease outbreaks in marine-farmed Atlantic salmon in the Northern hemisphere. In the Southern hemisphere, ISAV was first detected in Chile in 1999 in marine-farmed Coho salmon (Oncorhynchus kisutch). In contrast to the classical presentation of ISA in Atlantic salmon, the presence of ISAV in Chile until now has only been associated with a clinical condition called Icterus Syndrome in Coho salmon and virus isolation has not always been possible. During the winter of 2007, unexplained mortalities were registered in market-size Atlantic salmon in a grow-out site located in Chiloé in Region X of Chile. We report here the diagnostic findings of the first significant clinical outbreak of ISA in marine-farmed Atlantic salmon in Chile and the first characterization of the ISAV isolated from the affected fish.

Results

In mid-June 2007, an Atlantic salmon marine farm site located in central Chiloé Island in Region X of Chile registered a sudden increase in mortality following recovery from an outbreak of Pisciricketsiosis, which rose to a cumulative mortality of 13.6% by harvest time. Based on the clinical signs and lesions in the affected fish, and laboratory tests performed on the fish tissues, a confirmatory diagnosis of ISA was made; the first time ISA in its classical presentation and for the first time affecting farmed Atlantic salmon in Chile. Rapid sequencing of the virus-specific RT-PCR products amplified from the fish tissues identified the virus to belong to the European genotype (Genotype I) of the highly polymorphic region (HPR) group HPR 7b, but with an 11-amino acid insert in the fusion glycoprotein, and ability to cause cytopathic effects (CPE) in CHSE-214 cell line, characteristics which make it distinct from common European Genotype ISAV isolates from Europe and North America.

Conclusion

In conclusion, the present work constitutes the first report of a case of ISA in farmed Atlantic salmon in Chile. The clinical signs and lesions are consistent with the classical descriptions of the disease in marine-farmed Atlantic salmon in the Northern hemisphere. The outbreak was caused by ISAV of European genotype (or Genotype I) of HPR 7b but distinct from common European Genotype ISAV isolates.
RNase footprinting demonstrates antigenomic hepatitis delta virus ribozyme structural rearrangement as a result of self-cleavage reaction
Authors: Savochkina Larissa , Alekseenkova Victoria , Belyanko Tatyana , Dobrynina Nadezhda , Beabealashvilli Robert
Published: August 2008

Background

Hepatitis delta virus (HDV) is a satellite virus of hepatitis B. During viral replication the 1700-nucleotide-long genomic RNA and its complement, the antigenomic RNA, undergo self-cleavage catalyzed by internal ribozyme motifs that are essential for propagation of the virus in vivo. These self-cleavage activities are provided by 85-nucleotide-long sequence elements, the genomic and antigenomic forms of HDV ribozyme. Recently four permuted variants of the antigenomic HDV cis-ribozyme with a self-cleavage site located at the 5' proximity, in the middle, or nearby the 3' end of the molecule were constructed and synthesized. These constructs exhibit equal activity, a bi-phasic kinetics of self-cleavage reaction and reaction products with low and high stability. We have used ribonuclease probing to footprint the structures of uncleaved and post-cleaved forms of the antigenomic HDV ribozymes in solution. Uncleaved ribozymes, associated and individual products of the self-cleavage reaction were analyzed using ribonuclease and Fe(II)-EDTA protection assays to reveal the differences in the structure of pre- and post-cleaved antigenomic HDV ribozyme in solution.

Findings

Our findings demonstrate that a significant conformational change accompanies catalysis in the antigenomic HDV ribozyme in solution, in contrast to minor conformational switch observed in crystals of the genomic form. This study indicates that changes in the structure of stem P1 and stem P4 are minor, those of the region ascribed to stem P2, stem P3 and loop l3 are dramatic, while stem P1.1 results from the self-cleavage reaction.

Conclusion

Our data agree with the structure of post-cleaved and disagree with that of pre-cleaved forms of HDV ribozyme published elsewhere.
Brain region-specificity of palmitic acid-induced abnormalities associated with Alzheimer's disease
Authors: Patil Sachin , Balu Deebika , Melrose Joseph , Chan Christina
Published: August 2008

Background

Alzheimer's disease (AD) is a progressive, neurodegenerative disease mostly affecting the basal forebrain, cortex and hippocampus whereas the cerebellum is relatively spared. The reason behind this region-specific brain damage in AD is not well understood. Here, we report our data suggesting "differential free fatty acid metabolism in the different brain areas" as a potentially important factor in causing the region-specific damage observed in AD brain.

Findings

The astroglia from two different rat brain regions, cortex (region affected in AD) and cerebellum (unaffected region), were treated with 0.2 mM of palmitic acid. The conditioned media were then transferred to the cortical neurons to study the possible effects on the two main, AD-associated protein abnormalities, viz. BACE1 upregulation and hyperphosphorylation of tau. The conditioned media from palmitic-acid treated cortical astroglia, but not the cerebellar astroglia, significantly elevated levels of phosphorylated tau and BACE1 in cortical neurons as compared to controls (47 ± 7% and 45 ± 4%, respectively).

Conclusion

The present data provide an experimental explanation for the region-specific damage observed in AD brain; higher fatty acid-metabolizing capacity of cortical astroglia as compared to cerebellar astroglia, may play a causal role in increasing vulnerability of cortex in AD, while sparing cerebellum.