bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity of molecular target detection by multispectral optoacoustic tomography (MSOT)
Authors: Razansky Daniel , Baeten John , Ntziachristos Vasilis
Published: February 2009

Optoacoustic imaging is emerging as a noninvasive imaging modality that can resolve optical contrast through several millimeters to centimeters of tissue with the resolution achieved by ultrasound imaging. More recently, applied at multiple illumination wavelengths, multispectral optoacoustic tomography (MSOT) offered the ability to effectively visualize tissue biomarkers by resolving their distinct spectral signatures. While the imaging potential of the method has been demonstrated, little is known on the sensitivity performance in resolving chromophoric and fluorescent substances, such as optical functional and molecular reporters. Herein the authors investigate the detection capacity and physical limits of tomographic optoacoustic imaging by simulating signals originating from absorbing spheres in tissue‐mimicking media. To achieve this, a modified optoacoustic equation is employed to incorporate wavelength‐dependent propagation and attenuation of diffuse light and ultrasound. The theoretical predictions are further validated in phantom experiments involving Cy5.5, a common near‐infrared fluorescent molecular agent.
Characterization of scatter in cone‐beam CT breast imaging: Comparison of experimental measurements and Monte Carlo simulation
Authors: Chen Yu , Liu Bob , O'Connor J. Michael , Didier Clay S. , Glick Stephen J.
Published: February 2009

It is commonly understood that scattered radiation in x‐ray computed tomography (CT) degrades the reconstructed image. As a precursor to developing scatter compensation methods, it is important to characterize this scatter using both empirical measurements and Monte Carlo simulations. Previous studies characterizing scatter using both experimental measurements and Monte Carlo simulations have been reported in diagnostic radiology and conventional mammography. The emerging technology of cone‐beam CT breast imaging (CTBI) differs significantly from conventional mammography in the breast shape and imaging geometry, aspects that are important factors impacting the measured scatter. This study used a bench‐top cone‐beam CTBI system with an indirect flat‐panel detector. A cylindrical phantom with equivalent composition of 50% fibroglandular and 50% adipose tissues was used, and scatter distributions were measured by beam stop and aperture methods. The GEANT4‐based simulation package GATE was used to model x‐ray photon interactions in the phantom and detector. Scatter to primary ratio (SPR) measurements using both the beam stop and aperture methods were consistent within 5% after subtraction of nonbreast scatter contributions and agree with the low energy electromagnetic model simulation in GATE. The validated simulation model was used to characterize the SPR in different CTBI conditions. In addition, a realistic, digital breast phantom was simulated to determine the characteristics of various scatter components that cannot be separated in measurements. The simulation showed that the scatter distribution from multiple Compton and Rayleigh scatterings, as well as from the single Compton scattering, has predominantly low‐frequency characteristics. The single Rayleigh scatter was observed to be the primary contribution to the spatially variant scatter component.
A detailed radiobiological and dosimetric analysis of biochemical outcomes in a case‐control study of permanent prostate brachytherapy patients
Authors: Butler Wayne M. , Stewart Renee R. , Merrick Gregory S.
Published: February 2009

The purpose of this study is to determine dosimetric and radiobiological predictors of biochemical control after recalculation of prostate implant dosimetry using updated AAPM Task Group 43 (TG‐43) parameters and the radiobiological parameters recommended by TG‐137. All biochemical failures among patients implanted with or sources between 1994 and March 2006 were matched 2:1 with nonfailure controls. The individual matching was by risk group, radionuclide, prescribed dose, and time of implant (one match before and one after the failed patient) resulting in a median follow‐up of . Complete dose volume histogram (DVH) data were recalculated for all 55 cases and 110 controls after updating the original source strength by the retrospectively determined ratios of TG‐43. Differential DVH data were acquired in 179 increments of prostate volume versus percentage prescribed dose. At each incremental dose level , the biologically equivalent dose , equivalent uniform dose , and tumor control probability were calculated from the implant dose plus any external beam delivered to the patient. Total BED, EUD, and TCP were then derived from the incremental values for comparison with single point dosimetric quality parameters and DVH‐based averages. There was no significant difference between failures and controls in terms of total BED (143 vs ), EUD (95 vs ), or TCP (0.87 vs 0.89). Conditional logistic regression analysis factored out the matching variables and stratified the cohort into each case and its controls, but no radiobiological parameter was predictive of biochemical failure. However, there was a significant difference between radiobiological parameters of and due to less complete coverage of the target volume by the former isotope. The implant BED and TCP were highly correlated with the and natural prescription doses and a series of mean DVH‐based doses such as the harmonic mean and expressions of the generalized EUD. In this case‐control study of prostate brachytherapy biochemical failures and nonfailures, there were no radiobiological parameters derived from detailed DVH‐based analysis that predicted for biochemical control. This may indicate that in our approach, implant dosimetry is at or near the limits of clinically effective dose escalation.
Occurrence of a highly antiviral agent in plants treated with Boerhaavia diffusa inhibitor
Authors: Verma H. N. , Awasthi L. P.
Published: February 2009

A naturally occurring glycoprotein present in Boerhaavia diffusa root extract (BD inhibitor), causes plant cells to produce a highly active antiviral agent (AVA) that defends cells against infection by viruses. AVA was present in inhibitor-treated plants only, but not in nontreated plants, and was produced 2–48 h after treatment with BD inhibitor. AVA was effective not only in plant species in which it was produced but in other plant species as well. Crude AVA was active both in vitro and in vivo. In vitro, it markedly reduced the infectivity of viruses, and in vivo, the virus content in AVA-treated leaves and leaf discs was considerably suppressed. The AVA showed the characteristics of protein.
Alterations in the physiology of CO2 exchange in tomato plants grown in CO2-enriched atmospheres
Authors: Hicklenton Peter R. , Jolliffe Peter A.
Published: February 2009

Young, greenhouse-grown tomato plants were transferred to growth cabinets where they were maintained in normal air (0.03% CO2) or in air enriched to 0.1 or 0.5% CO2. CO2 enrichment increased net assimilation rate but decreased leaf area ratio. As a result, relative growth rate was greatest at 0.1% CO2 and was less in 0.5% CO2 than in 0.03% CO2. Gas exchange measurements were made on the third true leaf of plants from different CO2 regimes. They indicated that growth under conditions of CO2 enrichment affected photosynthesis at an early stage of leaf development (leaf plastochron index (PI) = 5) but not at a later stage (PI = 10.5). The effects were linked to changes in mesophyll resistance, not stomatal resistance. At PI = 5 and under equivalent test conditions of irradiance and CO2 concentration, net photosynthesis tended to be increased following growth in 0.1% CO2 but was decreased or unchanged by 0.5% CO2. Young leaves developed in 0.1% CO2 were less subject to photosynthetic inhibition by atmospheric oxygen and had low CO2 compensation points. CO2 enrichment also affected the activities of the enzymes ribulose-1,5-bisphosphate carboxylase and glycolic acid oxidase and the enzyme responses corresponded well with the gas exchange responses. The results indicate that photosynthetic adaptations may occur in response to the concentration of CO2 present during growth, and that enrichment to concentrations much above 0.1% CO2 may be detrimental to net photosynthesis and growth rate.
Photoinduction des périthèces du Nectria galligena. I. Influence de la lumière blanche
Authors: Dehorter B. , Lacoste L.
Published: February 2009

The ascocarps of N. galligena Bres. were induced by exposures to white light with variations in time, rhythm, and intensity. It was shown that perithecia could be photoinduced by a single 12-h photoperiod at 10 μW cm−2 or by continuous irradiations at 750 μW cm-2 for 30 days. These light requirements varied according to the stage of sexual development: perithecia were initiated by a 12-h exposure to light between the 7th and 8th day, but daily 12-h exposures between the 7th and 22nd days were necessary for the best ascocarp development. Ascospore formation did not require light exposure. Light did not produce its effect on sexual reproduction before the 7th day of mycelial growth; its maximum stimulation occurred between the 7th and 10th day.Some biological photoresponses were very similar to the sexual induction which appears in the dark after the addition of mycosporine (P310) to the growth medium. Thus, mycosporine is suggested to act mainly on ascocarp initiation; complete sexual differentiation being achieved by some other photoinduced mycelial products.
Lichens as indicators of fluoride emission from a phosphorus plant, Long Harbour, Newfoundland, Canada
Authors: Roberts B. A. , Thompson L. K.
Published: February 2009

Fluoride concentrations in the terrestrial lichens Cladina rangiferina (L.) Harm, and Cladina stellaris (Opiz.) Brodo. were correlated inversely with distance from an industrial plant producing elemental phosphorus at Long Harbour, Nfld., in the direction (NE) of the prevailing wind. The fluoride concentrations ranged from 2830 ppm dry weight in a severely damaged area close to the emission source to 15.5 ppm (dry weight) 12 km NE of the industrial plant. Control samples from unpolluted areas had an average fluoride content of 6.4 ppm dry weight. The minimum observed damage symptoms occurred when these lichens had a fluoride content of 25 ppm dry weight. Damage symptoms included discolouration and structure loss. Discolouration effects were not as pronounced as observed on Abies balsamea (L.) Mill, or on Polytrichum commune (Hedw.) but combined with structure loss allowed the degree of damage to be readily identified in the field. Fluoride concentrations in these terrestrial lichens are compared with levels in soil humus, A. balsamea and some terrestrial bryophytes in four damage zones. The lichen tissue had, on average, twice as much fluoride as occurred in soil humus from the same site and about one half the amount of fluoride found in the terrestrial bryophyte P. commune. The effects of fluoride emissions on the epiphytic lichens Hypogymnia physodes (L.) W. Wats, and Alectoria sarmentosa (Ach.) Ach. in this area are also discussed.
CRITICAL POINTS OF PAIRS OF VARIETIES OF ALGEBRAS
Authors: GILLIBERT PIERRE
Published: February 2009

For a class [Formula: see text] of algebras, denote by Conc[Formula: see text] the class of all (∨, 0)-semilattices isomorphic to the semilattice ConcA of all compact congruences of A, for some A in [Formula: see text]. For classes [Formula: see text] and [Formula: see text] of algebras, we denote by [Formula: see text] the smallest cardinality of a (∨, 0)-semilattices in Conc[Formula: see text] which is not in Conc[Formula: see text] if it exists, ∞ otherwise. We prove a general theorem, with categorical flavor, that implies that for all finitely generated congruence-distributive varieties [Formula: see text] and [Formula: see text], [Formula: see text] is either finite, or ℵn for some natural number n, or ∞. We also find two finitely generated modular lattice varieties [Formula: see text] and [Formula: see text] such that [Formula: see text], thus answering a question by J. Tůma and F. Wehrung.
DEFINING RELATIONS OF LOW DEGREE OF INVARIANTS OF TWO 4 × 4 MATRICES
Authors: DRENSKY VESSELIN , LA SCALA ROBERTO
Published: February 2009

The trace algebra Cnd over a field of characteristic 0 is generated by all traces of products of d generic n × n matrices, n, d ≥ 2. Minimal sets of generators of Cnd are known for n = 2 and 3 for any d and for n = 4 and 5 and d = 2. The explicit defining relations between the generators are found for n = 2 and any d and for n = 3, d = 2 only. Defining relations of minimal degree for n = 3 and any d are also known. The minimal degree of the defining relations of any homogeneous minimal generating set of C42 is equal to 12. Starting with the generating set given recently by Drensky and Sadikova, we have determined all relations of degree ≤ 14. For this purpose we have developed further algorithms based on representation theory of the general linear group and easy computer calculations with standard functions of Maple.
DEFINING POWER SUMS OF n AND φ(n) INTEGERS
Authors: SINGH JITENDER
Published: February 2009

Let n be a positive integer and φ(n) denotes the Euler phi function. It is well known that the power sum of n can be evaluated in closed form in terms of n. Also, the sum of all those φ(n) positive integers that are coprime to n and not exceeding n, is expressible in terms of n and φ(n). Although such results already exist in literature, but here we have presented some new analytical results in these connections. Some functional and integral relations are derived for the general power sums.
POWER RESIDUES OF FOURIER COEFFICIENTS OF ELLIPTIC CURVES WITH COMPLEX MULTIPLICATION
Authors: WESTON TOM , ZAUROVA ELENA
Published: February 2009

Fix m greater than one and let E be an elliptic curve over Q with complex multiplication. We formulate conjectures on the density of primes p (congruent to one modulo m) for which the pth Fourier coefficient of E is an mth power modulo p; often these densities differ from the naive expectation of 1/m. We also prove our conjectures for m dividing the number of roots of unity lying in the CM field of E; the most involved case is m = 4 and complex multiplication by Q(i).
FOURIER COEFFICIENTS OF GENERALIZED MODULAR FORMS OF NEGATIVE WEIGHT
Authors: RAJI WISSAM
Published: February 2009

The Fourier coefficients of classical modular forms of negative weights have been determined for the case for which F(τ) belongs to a subgroup of the full modular group [9]. In this paper, we determine the Fourier coefficients of generalized modular forms of negative weights using the circle method.
A GENERALIZATION OF THE SATO–TATE CONJECTURE
Authors: KUO WENTANG
Published: February 2009

The original Sato–Tate Conjecture concerns the angle distribution of the eigenvalues arisen from non-CM elliptic curves. In this paper, we formulate an analogue of the Sato–Tate Conjecture on automorphic forms of ( GLn) and, under a holomorphic assumption, prove that the distribution is either uniform or the generalized Sato–Tate measure.
Using formal specifications to support testing
Authors: Hierons Robert M. , Bogdanov Kirill , Bowen Jonathan P. , Cleaveland Rance , Derrick John , Dick Jeremy , Gheorghe Marian , Harman Mark , Kapoor Kalpesh , Krause Paul , Lüttgen Gerald , Simons Anthony J. H. , Vilkomir Sergiy , Woodward Martin R. , Zedan Hussein
Published: February 2009

Formal methods and testing are two important approaches that assist in the development of high-quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing.
A unified information-theoretic framework for viewpoint selection and mesh saliency
Authors: Feixas Miquel , Sbert Mateu , González Francisco
Published: February 2009

Viewpoint selection is an emerging area in computer graphics with applications in fields such as scene exploration, image-based modeling, and volume visualization. In particular, best view selection algorithms are used to obtain the minimum number of views (or images) in order to understand or model an object or scene better. In this article, we present a unified framework for viewpoint selection and mesh saliency based on the definition of an information channel between a set of viewpoints (input) and the set of polygons of an object (output). The mutual information of this channel is shown to be a powerful tool to deal with viewpoint selection, viewpoint stability, object exploration and viewpoint-based saliency. In addition, viewpoint mutual information is extended using saliency as an importance factor, showing how perceptual criteria can be incorporated to our method. Although we use a sphere of viewpoints around an object, our framework is also valid for any set of viewpoints in a closed scene. A number of experiments demonstrate the robustness of our approach and the good behavior of the proposed measures.
A psychophysical investigation of global illumination algorithms used in augmented reality
Authors: Hattenberger Timothy J. , Fairchild Mark D. , Johnson Garrett M. , Salvaggio Carl
Published: February 2009

The overarching goal of this research was to compare different rendering solutions in order to understand why some yield better results specifically when applied to rendering synthetic objects into real photographs. A psychophysical experiment was conducted in which the composite images were judged for accuracy against the original photograph. In addition, iCAM, an image color appearance model was also used to calculate image differences for the same set of images. Conclusions obtained included the effect of global illumination on the accuracy of the final composite rendering. Also, it was discovered that the original rendering with all of its artifacts is not necessarily an indicator of the final composite image's judged accuracy. Finally, initial results show promise in using iCAM to predict a relationship similar to the psychophysics, which could eventually be used in-the-rendering-loop to achieve photorealism with minimized computation.
Negative efficacy of fixed gain error reducing shared control for training in virtual environments
Authors: Li Yanfang , Patoglu Volkan , O'Malley Marcia K.
Published: February 2009

Virtual reality with haptic feedback provides a safe and versatile practice medium for many manual control tasks. Haptic guidance has been shown to improve performance of manual control tasks in virtual environments; however, the efficacy of haptic guidance for training in virtual environments has not been studied conclusively. This article presents experimental results that show negative efficacy of haptic guidance during training in virtual environments. The haptic guidance in this study is a fixed-gain error-reducing shared controller, with the control effort overlaid on the dynamics of the manual control task during training. Performance of the target-hitting manual control task in the absence of guidance is compared for three training protocols. One protocol contained no haptic guidance and represented virtual practice. Two protocols utilized haptic guidance, varying the duration of exposure to guidance during the training sessions. Exposure to the fixed-gain error-reducing shared controller had a detrimental effect on performance of the target-hitting task at the conclusion of a month-long training protocol, regardless of duration of exposure. While the shared controller was designed with knowledge of the task and an intuitive sense of the motions required to achieve good performance, the results indicate that the acquisition of motor skill is a complex phenomenon that is not aided with haptic guidance during training as implemented in this experiment.
Perception of image motion during head movement
Authors: Li Li , Adelstein Bernard D. , Ellis Stephen R.
Published: February 2009

We examined human perception of head-referenced image motion during concurrent head movement. The visual stimulus was a checkerboard image in a head mounted display that moved from side-to-side. Observers rated the magnitude of the checkerboard motion while either rotating their head about a vertical axis (yaw), about a horizontal axis (pitch), or holding it still. In Experiment 1, we tested four image oscillation frequencies (0.25, 0.5, 1, and 2 Hz) while holding the head motion frequency constant at 0.5 Hz. In Experiment 2, we tested three head motion frequencies (0.25, 0.5, and 1 Hz) while holding the image oscillation frequency constant at 1 Hz. Across all image and head motion frequencies, perceptual sensitivity to image motion was reduced by about 45% during horizontal head movement. During vertical head movement, perceptual sensitivity was reduced by about 25% when head and image motion were of the same frequency. Compared with when the head was still, horizontal and vertical head movements produced a downward shift of about 10% in overall motion magnitude estimation response. Findings from this study provide virtual environment developers with a quantitative description of the influence of concurrent head movement on the perception of frontoparallel image motion.
Classifying pretended and evoked facial expressions of positive and negative affective states using infrared measurement of skin temperature
Authors: Khan Masood Mehmood , Ward Robert D. , Ingleby Michael
Published: February 2009

Earlier researchers were able to extract the transient facial thermal features from thermal infrared images (TIRIs) to make binary distinctions between the expressions of affective states. However, effective human-computer interaction would require machines to distinguish between the subtle facial expressions of affective states. This work, for the first time, attempts to use the transient facial thermal features for recognizing a much wider range of facial expressions. A database of 324 time-sequential, visible-spectrum, and thermal facial images was developed representing different facial expressions from 23 participants in different situations. A novel facial thermal feature extraction, selection, and classification approach was developed and invoked on various Gaussian mixture models constructed using: neutral and pretended happy and sad faces, faces with multiple positive and negative facial expressions, faces with neutral and six (pretended) basic facial expressions, and faces with evoked happiness, sadness, disgust, and anger. This work demonstrates that (1) infrared imaging can be used to observe the affective-state-specific facial thermal variations, (2) pixel-grey level analysis of TIRIs can help localise significant facial thermal feature points along the major facial muscles, and (3) cluster-analytic classification of transient thermal features can help distinguish between the facial expressions of affective states in an optimized eigenspace of input thermal feature vectors. The observed classification results exhibited influence of a Gaussian mixture model's structure on classifier-performance. The work also unveiled some pertinent aspects of future research on the use of facial thermal features in automated facial expression classification and affect recognition.
Resource overbooking and application profiling in a shared Internet hosting platform
Authors: Urgaonkar Bhuvan , Shenoy Prashant , Roscoe Timothy
Published: February 2009

In this article, we present techniques for provisioning CPU and network resources in shared Internet hosting platforms running potentially antagonistic third-party applications. The primary contribution of our work is to demonstrate the feasibility and benefits of overbooking resources in shared Internet platforms. Since an accurate estimate of an application's resource needs is necessary when overbooking resources, we present techniques to profile applications on dedicated nodes, possibly while in service, and use these profiles to guide the placement of application components onto shared nodes. We then propose techniques to overbook cluster resources in a controlled fashion. We outline an empirical appraoch to determine the degree of overbooking that allows a platform to achieve improvements in revenue while providing performance guarantees to Internet applications. We show how our techniques can be combined with commonly used QoS resource allocation mechanisms to provide application isolation and performance guarantees at run-time. We implement our techniques in a Linux cluster and evaluate them using common server applications. We find that the efficiency (and consequently revenue) benefits from controlled overbooking of resources can be dramatic. Specifically, we find that overbooking resources by as little as 1% we can increase the utilization of the cluster by a factor of two, and a 5% overbooking yields a 300--500% improvement, while still providing useful resource guarantees to applications.
Revisiting coroutines
Authors: Moura Ana Lúcia De , Ierusalimschy Roberto
Published: February 2009

This article advocates the revival of coroutines as a convenient general control abstraction. After proposing a new classification of coroutines, we introduce the concept of full asymmetric coroutines and provide a precise definition for it through an operational semantics. We then demonstrate that full coroutines have an expressive power equivalent to one-shot continuations and one-shot delimited continuations. We also show that full asymmetric coroutines and one-shot delimited continuations have many similarities, and therefore present comparable benefits. Nevertheless, coroutines are easier implemented and understood, especially in the realm of procedural languages.
The computational power and complexity of constraint handling rules
Authors: Sneyers Jon , Schrijvers Tom , Demoen Bart
Published: February 2009

Constraint Handling Rules (CHR) is a high-level rule-based programming language which is increasingly used for general-purpose programming. We introduce the CHR machine, a model of computation based on the operational semantics of CHR. Its computational power and time complexity properties are compared to those of the well-understood Turing machine and Random Access Memory machine. This allows us to prove the interesting result that every algorithm can be implemented in CHR with the best known time and space complexity. We also investigate the practical relevance of this result and the constant factors involved. Finally we expand the scope of the discussion to other (declarative) programming languages.
"Yes, it can be done"
Authors: Vardi Moshe Y.
Published: February 2009

The 2008 presidential campaign slogan "Yes, We Can" is the English translation of the United Farm Workers' 1972 slogan "Sí, se puede," or "Yes, it can be done."
Betting on ideas
Authors: Goth Gregory
Published: February 2009

Advanced computational models are enabling researchers to create increasingly sophisticated prediction markets.
The profession of ITIs software engineering engineering?
Authors: Denning Peter J. , Riehle Richard D.
Published: February 2009

Software engineering continues to be dogged by claims it is not engineering. Adopting more of a computer-systems view may help.
ViewpointAdvising students for success
Authors: Ullman Jeffrey D.
Published: February 2009

Some advice for those doing the advising (and what the advisors can learn from the advisees).
Better scripts, better games
Authors: White Walker , Koch Christoph , Gehrke Johannes , Demers Alan
Published: February 2009

Smarter, more powerful scripting languages will improve game performance while making gameplay development more efficient.
Erlang for concurrent programming
Authors: Larson Jim
Published: February 2009

Designed for concurrency from the ground up, the Erlang language can be a valuable tool to help solve concurrent problems.
Statecharts in the making
Authors: Harel David
Published: February 2009

How avionics work led to a graphical language for reactive systems where the diagrams themselves define the system's behavior.
The dancing body as a screen
Authors: Barnett Angela
Published: February 2009

The aesthetic of using the human body as a living screen to project video, motion graphics, or animation is being explored by various artists worldwide. In the modern society of mass media and computerization, increasingly more dance productions are using modern technology to merge the digital image with the live performer. This article will connect the synchronization of motion graphics and human movement with the ritualistic markings of the body, thus forming a new type of expression in contemporary dance. Case studies of performances and interviews with choreog-raphers, dancers, and animators will demonstrate how projection is being integrated to form a synchronized hybrid between the human bodyand digitally mediated technology.
Meaningful data
Authors: Cmielewski Leon , Finnegan Ann , Starrs Josephine
Published: February 2009

Art often relies on a certain obliqueness or ambiguity to encourage contemplative reflection and allow room for the viewer to generate their own complex multiple readings of the artwork. However, “good design” approaches to graphically representing statistical information emphasize clarity and efficiency of information transfer. This inherent conflict between the domains of art and design is just one of the issues that was grappled with in the creation of the
Seeker
art installation by Australian artists Leon Cmielewski and Josephine Starrs. Other strategies to enhance audience engagement were the creation of slow, meditative visualizations, the use of interaction, and the accumulation and mapping of viewer responses within the artwork.
What went wrong? A survey of problems in game development
Authors: Petrillo Fábio , Pimenta Marcelo , Trindade Francisco , Dietrich Carlos
Published: February 2009

Despite its growth and profitability, many reports about game projects show that their production is not a simple task, but one beset by common problems and still distant from having a healthy and synergetic work process. The goal of this article is to survey the problems in the development process of electronic games, which are mainly collected from game postmortems, by exploring their similarities and differences to well-known problems in traditional information systems.
Pride and Prejudice: (The
Vasa
)
Authors: Neville-Neil George V.
Published: February 2009

I teach computer science to undergraduate students at a school in California, and one of my friends in the English department, of all places, made an interesting comment to me the other day. He wanted to know if my students had ever read
Frankenstein
and if I felt it would make them better engineers. I asked him why he thought I should assign this book, and he said he felt that a book could change the way in which people think about their relationship to the world, and in particular to technology. He wasn’t being condescending; he was dead serious. Given the number of Frankenstein-like projects that seem to get built with information technology, perhaps it’s not a bad idea to teach these lessons to computer science undergraduates, to give them some notion that they have a social responsibility. Do you agree?
CTO Roundtable: Virtualization Part I
Authors: Creeger Mache
Published: February 2009

The topic of this forum is virtualization. When investing in virtualization technologies, IT managers need to know what is considered standard practice and what is considered too leading edge and risky for near-term deployment. For this forum we’ve assembled several leading experts on virtualization to discuss what those best practices should be. While the participants might not always agree with each other, we hope their insights will help IT managers navigate the virtualization landscape and make informed decisions on how best to use the technology. Next month we will present part two of this forum, discussing such topics as clouds and virtualization, using virtualization to streamline desktop delivery, and how to choose appropriate virtual-machine platforms and management tools.
The Obama Campaign
Authors: Boer Benjamin
Published: February 2009

On January 3, 2008, I sat in the boiler room waiting for the caucus to commence. At 7 p.m. the doors had been open for about an hour: months of preparation were coming to fruition. The phone calls had been made, volunteers had been canvassing, and now the moment had come. Could Barack Obama win the Iowa caucus? Doors closed and the first text message came from a precinct: it looked like a large attendance. Then came the second, the third, the fourth. Each was typed into our model, and a projection was starting to form. The fifth, the sixth, and now the seventh. The projection of attendance seemed solid. The Des Moines Register’s poll had been correct: more than 240,000 people participated in the Iowa caucus. The numbers were astounding, and Barack Obama was going to win it. Simple technologies enabled the campaign to create a simple, yet effective, predictive dashboard.
Review of "Wireless Ad Hoc and Sensor Networks (1st ED.) by Houda Labiod," John Wiley & Sons, Inc., 2008, $165.00, ISBN: 1848210035
Authors: Berni Alessandro
Published: February 2009

Review of "Wireless Ad Hoc and Sensor Networks (1st ED.) by Houda Labiod," John Wiley & Sons, Inc., 2008, $165.00, ISBN: 1848210035
Calendar
Authors: Stanik John
Published: February 2009

SCALE (Southern California Linux Expo)
Searching for a lion in the desert
Authors: Arnon Shlomi , Dolev Shlomi , Kat Ronen , Kedar Debbie
Published: February 2009

In this paper we address the task of locating and mapping sensor nodes equipped with passive optical transmitters deployed within a wireless sensor network. The passive transmitter is in the form of a modulatable corner cube retro-reflector (CCR) and is interrogated by a base station equipped with a variable sized laser beam prior to data harvesting using optical wireless communication. We propose and discuss an efficient acquisition algorithm based on the binary search concept and evaluate its performance in locating a solitary sensor node. We demonstrate the use of an analytical tool for assessing the acquisition cost for different error probability distributions and search regimes. The common line-of-sight (LOS) requirement for both sensor location and data harvesting renders the need for individual sensor node identification redundant and thus yields a simplified search regime by comparison with previously published research on node localisation.
On the application of epidemical spreading in collaborative context-aware computing
Authors: Anagnostopoulos Christos , Hadjiefthymiades Stathes
Published: February 2009

Pervasive Computing Research Group, Department of Informatics and Telecommunications, University of Athens, Panepistimiopolis, Ilissia, 15784, Athens, Greece. We investigate the very important concept of collaborative context awareness. Applications operating in nodes with spatial proximity and network connectivity exchange the contextual information (context) captured by their sensors (or other similar data sources). Such scheme improves the characteristics of the context aware application (e.g., robustness). The exchange of context in our model is progressed beyond a simple flooding scheme. We adopt an epidemic model, which relays information in a stochastic manner. In our model, nodes have a reasoning capability, which can further process and transform the incoming context. The derived context can be relayed throughout the network. This multi-epidemic model relies on semantic dependencies, which are modeled through a hierarchical representation scheme. We investigate the efficiency of the proposed architecture in light of different spreading parameters. Our simulations take into account the temporal validity of the exchanged context (i.e., relayed information remains valid for a certain period of time), the status of the sensing elements and the mobility of nodes. Our findings are quite promising for the emerging area of context aware application engineering.
RANTES release by human adipose tissue in vivo and evidence for depot-specific differences
Authors: Madani Rana , Karastergiou Kalypso , Ogston Nicola C. , Miheisi Nazar , Bhome Rahul , Haloob Nora , Tan Garry D. , Karpe Fredrik , Malone-Lee James , Hashemi Majid , Jahangiri Marjan , Mohamed-Ali Vidya
Published: February 2009

Obesity is associated with elevated inflammatory signals from various adipose tissue depots. This study aimed to evaluate release of regulated on activation, normal T cell expressed and secreted (RANTES) by human adipose tissue in vivo and ex vivo, in reference to monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) release. Arteriovenous differences of RANTES, MCP-1, and IL-6 were studied in vivo across the abdominal subcutaneous adipose tissue in healthy Caucasian subjects with a wide range of adiposity. Systemic levels and ex vivo RANTES release were studied in abdominal subcutaneous, gastric fat pad, and omental adipose tissue from morbidly obese bariatric surgery patients and in thoracic subcutaneous and epicardial adipose tissue from cardiac surgery patients without coronary artery disease. Arteriovenous studies confirmed in vivo RANTES and IL-6 release in adipose tissue of lean and obese subjects and release of MCP-1 in obesity. However, in vivo release of MCP-1 and RANTES, but not IL-6, was lower than circulating levels. Ex vivo release of RANTES was greater from the gastric fat pad compared with omental ( P = 0.01) and subcutaneous ( P = 0.001) tissue. Epicardial adipose tissue released less RANTES than thoracic subcutaneous adipose tissue in lean ( P = 0.04) but not obese subjects. Indexes of obesity correlated with epicardial RANTES but not with systemic RANTES or its release from other depots. In conclusion, RANTES is released by human subcutaneous adipose tissue in vivo and in varying amounts by other depots ex vivo. While it appears unlikely that the adipose organ contributes significantly to circulating levels, local implications of this chemokine deserve further investigation.
Breakdown of endocytosis in the oncogenic activation of receptor tyrosine kinases
Authors: Abella Jasmine V. , Park Morag
Published: February 2009

There is increasing evidence to support the concept that the malignant behavior of many tumors is sustained by the deregulated activation of growth factor receptors. Activation of receptor tyrosine kinases (RTKs) by their respective ligand(s) initiates cellular signals that tightly modulate cell proliferation, survival, differentiation and migration to ensure normal tissue patterning. Therefore, uncontrolled activation of such signals can have deleterious effects, leading to oncogenesis. To date, deregulation of most RTKs has been implicated in the development of cancer, although the mechanisms that lead to their deregulation are not yet fully understood ( 10 ). RTK endocytosis, the internalization and trafficking of receptors inside the cell, has long been established as a mechanism to attenuate RTK signaling. However, RTKs have been demonstrated to continue to signal along the endocytic pathway, which contributes to the spatio-temporal regulation of signal transduction. This review will focus on recent advances linking defective endocytosis of RTKs in the development of cancer.
Molecular Analysis of Activation-Induced Cytidine Deaminase Gene in Immunoglobulin-E Deficient Patients
Authors: Roa Sergio , Isidoro-Garcia Maria , Davila Ignacio , Laffond Elena , Lorente Felix , Gonzalez-Sarmiento Rogelio
Published: February 2009

Understanding how class switch recombination (CSR) is regulated to produce immunoglobulin E (IgE) has become fundamental because of the dramatic increase in the prevalence of IgE-mediated hypersensitivity reactions. CSR requires the induction of the enzyme AICDA in B cells. Mutations in AICDA have been linked to Hyper-IgM syndrome (HIGM2), which shows absence of switching to IgE as well as to IgG and IgA. Although isolated IgE deficiency is a rare entity, here we show some individuals with normal serum IgM, IgG, and IgA levels that had undetectable total serum IgE levels. We have analyzed theAICDAgene in these individuals to determine if there are mutations in AICDA that could lead to selective IgE deficiency. Conformational sensitive gel electrophoresis (CSGE) and sequencing analysis ofAICDAcoding sequences demonstrated sequence heterogeneity due to 5923A/G and 7888C/T polymorphisms, but did not reveal any novel mutation that might explain the selective IgE deficit.
Modeling Distance and Bandwidth Dependency of TOA‐Based UWB Ranging Error for Positioning
Authors: Bellusci Giovanni , Janssen Gerard J. M. , Yan Junlin , Tiberius Christian C. J. M.
Published: February 2009

A statistical model for the range error provided by TOA estimation
using UWB signals is given, based on UWB channel measurements
between 3.1 and 10.6 GHz. The range error has been modeled
as a Gaussian random variable for LOS and as a combination of a
Gaussian and an exponential random variable for NLOS. The distance
and bandwidth dependency of both the mean and the standard
deviation of the range error has been analyzed, and insight is
given in the different phenomena which affect the estimation
accuracy. A possible application of the model to weighted least
squares positioning is finally investigated. Noticeable
improvements compared to the traditional least squares method have
been obtained.
Behavioral Consequences of Delta-Opioid Receptor Activation in the Periaqueductal Gray of Morphine Tolerant Rats
Authors: Morgan Michael M. , Ashley Michelle D. , Ingram Susan L. , Christie MacDonald J.
Published: February 2009

Chronic morphine administration shifts delta-opioid receptors (DORs) from the cytoplasm to the plasma membrane. Given that microinjection of morphine into the PAG produces antinociception, it is hypothesized that the movement of DORs to the membrane will allow antinociception to the DOR agonist deltorphin II as a way to compensate for morphine tolerance. Tolerance was induced by twice daily injections of morphine (5, 10, or 20 mg/kg, subcutaneous) for 3.5 days. Microinjection of deltorphin into the vPAG 6 hours after the last morphine injection produced a mild antinociception that did not vary in a consistent manner across morphine pretreatment doses or nociceptive tests. In contrast, deltorphin caused a decrease in activity in morphine tolerant rats that was associated with lying in the cage. The decrease in activity and change in behavior indicate that chronic morphine administration alters DORs in the vPAG. However, activation of these receptors does not appear to compensate for the decrease in antinociception caused by morphine tolerance.
Automatic Generation of Web Applications from Visual High-Level Functional Web Components
Authors: Chen Quan Liang , Shimomura Takao
Published: February 2009

This paper presents high-level functional Web components such as frames, framesets, and pivot tables, which conventional development environments for Web applications have not yet supported. Frameset Web components provide several editing facilities such as adding, deleting, changing, and nesting of framesets to make it easier to develop Web applications that use frame facilities. Pivot table Web components sum up various kinds of data in two dimensions. They reduce the amount of code to be written by developers greatly. The paper also describes the system that implements these high-level functional components as visual Web components. This system assists designers in the development of Web applications based on the page-transition framework that models a Web application as a set of Web page transitions, and by using visual Web components, makes it easier to write processes to be executed when a Web page transfers to another.
Heat-Induced Perturbations of DNA Damage Signaling Pathways are Modulated by Molecular Chaperones
Authors: Laszlo Andrei , Fleischer Ilona
Published: February 2009

Heat is one of the most potent radiosensitizers known. Several randomized trials have shown that hyperthermia is a good adjuvant for radiotherapy at several different cancer sites. However, the mechanism(s) involved in the interaction of heat and radiation that lead to radiosensitization remain to be elucidated. In this report, we have determined that heat induces perturbations in some of the earliest events in the cellular response to DNA damage induced by ionizing radiation. We studied the effect of heat on the formation of complexes containing γ-H2AX/MDC1/53BP1 in heated-irradiated cells. We found that the formation of this complex was delayed in heated-irradiated cells, in a heat but not radiation dose–dependent manner. The length of the heat-induced delay of complex formation was attenuated in thermotolerant and heat radiosensitization–resistant cells. The length of the delay of γ-H2AX/MDC1/53BP1 complex formation correlated with the magnitude of heat radiosensitization and was modulated by the molecular chaperone Hsc70. Heat radiosensitization was attenuated in 53BP1-null cells, implying that the delay of the formation of the γ-H2AX/MDC1/53BP1 complex plays a role in heat radiosensitization. Heat also induced a delay of events in the DNA damage response that are downstream from 53BP1. Our results support the notion that heat-induced perturbations in the earliest events of the cellular response to ionizing radiation–induced DNA damage play a role in heat radiosensitization. [Cancer Res 2009;69(5):2042–9]
Sonic Hedgehog Signaling Pathway Is Activated in ALK-Positive Anaplastic Large Cell Lymphoma
Authors: Singh Rajesh R. , Cho-Vega Jeong Hee , Davuluri Yogesh , Ma Shuguang , Kasbidi Fatan , Milito Cristiane , Lennon Patrick A. , Drakos Elias , Medeiros L. Jeffrey , Luthra Rajyalakshmi , Vega Francisco
Published: February 2009

Deregulation of the sonic hedgehog (SHH) signaling pathway has been implicated in several cancers but has not been explored in T-cell lymphomas. Here, we report that the SHH/GLI1 signaling pathway is activated in anaplastic lymphoma kinase (ALK)–positive anaplastic large cell lymphoma (ALCL). We show that SHH, but not its transcriptional effector GLI1, is amplified in ALK+ ALCL tumors and cell lines, and that SHH and GLI1 proteins are highly expressed in ALK+ ALCL tumors and cell lines. We also show that inhibition of SHH/GLI1 signaling with cyclopamine-KAAD, as well as silencing GLI1 gene expression by small interfering (si)RNA, decreased cell viability and clonogenicity of ALK+ ALCL cells. Transfection of wild-type or mutant NPM-ALK into 293T cells showed that only wild-type NPM-ALK increased GLI1 protein levels and activated SHH/GLI1 signaling as shown by increase of CCND2 mRNA levels. Inhibition of ALK tyrosine kinase and phosphatidylinositol 3-kinase (PI3K)/AKT or forced expression of pAKT down-regulated or up-regulated SHH/GLI1 signaling, respectively. Inhibition of GSK3β in 293T cells also increased protein levels of GLI1. In conclusion, the SHH/GLI1 signaling pathway is activated in ALK+ ALCL. SHH/GLI1 activation is the result of SHH gene amplification and is further mediated by NPM-ALK through activation of PI3K/AKT and stabilization of GLI1 protein. There is a positive synergistic effect between the SHH/GLI1 and PI3K/AKT pathways that contributes to the lymphomagenic effect of NPM-ALK. [Cancer Res 2009;69(6):2550–8]