bluuebunny/crossref_metadata_2025 huggingface dataset:
VIDEO-BASED FACE RECOGNITION AND TRACKING FROM A ROBOT COMPANION
Authors: GERMA T. , LERASLE F. , SIMON T.
Published: June 2009

This paper deals with video-based face recognition and tracking from a camera mounted on a mobile robot companion. All persons must be logically identified before being authorized to interact with the robot while continuous tracking is compulsory in order to estimate the person's approximate position. A first contribution relates to experiments of still-image-based face recognition methods in order to check which image projection and classifier associations give the highest performance of the face database acquired from our robot. Our approach, based on Principal Component Analysis (PCA) and Support Vector Machines (SVM) improved by genetic algorithm optimization of the free-parameters, is found to outperform conventional appearance-based holistic classifiers (eigenface and Fisherface) which are used as benchmarks. Relative performances are analyzed by means of Receiver Operator Characteristics which systematically provide optimized classifier free-parameter settings. Finally, for the SVM-based classifier, we propose a non-dominated sorting genetic algorithm to obtain optimized free-parameter settings.

The second and central contribution is the design of a complete still-to-video face recognition system, dedicated to the previously identified person, which integrates face verification, as intermittent features, and shape and clothing color, as persistent cues, in a robust and probabilistically motivated way. The particle filtering framework, is well-suited to this context as it facilitates the fusion of different measurement sources. Automatic target recovery, after full occlusion or temporally disappearance from the field of view, is provided by positioning the particles according to face classification probabilities in the importance function. Moreover, the multi-cue fusion in the measurement function proves to be more reliable than any other individual cues.

Evaluations on key-sequences acquired by the robot during long-term operations in crowded and continuously changing indoor environments demonstrate the robustness of the tracker against such natural settings. Mixing all these cues makes our video-based face recognition system work under a wide range of conditions encountered by the robot during its movements. The paper concludes with a discussion of possible extensions.
TOWARDS PRACTICAL FACIAL FEATURE DETECTION
Authors: ECKHARDT MICAH , FASEL IAN , MOVELLAN JAVIER
Published: June 2009

Localizing facial features is a critical component in many computer vision applications such as expression recognition, face recognition, face tracking, animation, and red-eye correction. Practical applications require detectors that operate reliably under a wide range of conditions, including variations in illumination, pose, ethnicity, gender and age. One challenge for the development of such detectors is the inherent trade-off between robustness and precision. Robust detectors tend to provide poor localization and detectors sensitive to small changes in local structure, which are needed for precise localization, generate a large number of false alarms. Here we present an approach to this trade-off based on context dependent inference. First, robust detectors are used to detect contexts in which target features occur, then precise detectors are trained to localize the features given the detected context. This paper describes the approach and presents a thorough empirical examination of the parameters needed to achieve practical levels of performance, including the size of the training database, size of the detector's receptive fields and methods for information integration. The approach operates in real time and achieves, to our knowledge, the most accurate localization performance to date.
NONUNIFORM BRANEWORLD STARS: AN EXACT SOLUTION
Authors: OVALLE J.
Published: June 2009

In this paper the first exact interior solution to Einstein's field equations for a static and nonuniform braneworld star with local and nonlocal bulk terms is presented. It is shown that the bulk Weyl scalar [Formula: see text] is always negative inside the stellar distribution, and in consequence it reduces both the effective density and the effective pressure. It is found that the anisotropy generated by bulk gravity effect has an acceptable physical behavior inside the distribution. Using a Reissner–Nördstrom-like exterior solution, the effects of bulk gravity on pressure and density are found through matching conditions.
A DISCREPANCY PRINCIPLE FOR THE SOURCE POINTS LOCATION IN USING THE MFS FOR SOLVING THE BHCP
Authors: HON Y. C. , LI M.
Published: June 2009

Based on the discrepancy principle, we develop in this paper a new method of choosing the location of source points to solve the backward heat conduction problem (BHCP) by using the method of fundamental solutions (MFS). The standard Tikhonov regularization technique with the L curve method for an optimal regularized parameter is adopted for solving the resultant highly ill-conditioned system of linear equations. Numerical verifications of the proposed computational method are presented for both the one-dimensional and the two-dimensional BHCP.
SPHERICAL DESIGNS FROM THE NORM-3 SHELL OF INTEGRAL LATTICES
Authors: Shigezumi Junichi
Published: June 2009

A set of vectors all of which have a constant (non-zero) norm value in a Euclidean lattice is called a shell of the lattice. Venkov classified strongly perfect lattices of minimum 3 (Réseaux et "designs" sphérique, 2001), whose minimal shell is a spherical 5-design. This note considers the classification of integral lattices whose shells of norm 3 are 5-designs.
Hardware Decompression Techniques for FPGA-Based Embedded Systems
Authors: Koch Dirk , Beckhoff Christian , Teich Jürgen
Published: June 2009

In this work, we present hardware decompression accelerators for widening the bottleneck between slow nonvolatile memories on the one side and high-speed FPGA configuration interfaces and fast softcore CPUs on the other side. We discuss different compression algorithms suitable for a hardware accelerated decompression on FPGAs as well as on CPLDs. The algorithms will be investigated with respect to the achievable compression ratio, throughput, and hardware overhead. This leads to various decompressor implementations with one capable to decompress at high data rates of up to 400 megabytes per second under optimal conditions while only requiring slightly more than a hundred lookup tables. We will evaluate how these decompressors perform on configuration bitstreams for different FPGAs as well as for softcore CPU binaries.
Laminar
Authors: Roy Indrajit , Porter Donald E. , Bond Michael D. , McKinley Kathryn S. , Witchel Emmett
Published: June 2009

Decentralized information flow control (DIFC) is a promising model for writing programs with powerful, end-to-end security guarantees. Current DIFC systems that run on commodity hardware can be broadly categorized into two types: language-level and operating system-level DIFC. Language level solutions provide no guarantees against security violations on system resources, like files and sockets. Operating system solutions can mediate accesses to system resources, but are inefficient at monitoring the flow of information through fine-grained program data structures.

This paper describes Laminar, the first system to implement decentralized information flow control using a single set of abstractions for OS resources and heap-allocated objects. Programmers express security policies by labeling data with secrecy and integrity labels, and then access the labeled data in lexically scoped security regions. Laminar enforces the security policies specified by the labels at runtime. Laminar is implemented using a modified Java virtual machine and a new Linux security module. This paper shows that security regions ease incremental deployment and limit dynamic security checks, allowing us to retrofit DIFC policies on four application case studies. Replacing the applications' ad-hoc security policies changes less than 10% of the code, and incurs performance overheads from 1% to 56%. Whereas prior DIFC systems only support limited types of multithreaded programs, Laminar supports a more general class of multithreaded DIFC programs that can access heterogeneously labeled data.
TAJ
Authors: Tripp Omer , Pistoia Marco , Fink Stephen J. , Sridharan Manu , Weisman Omri
Published: June 2009

Taint analysis, a form of information-flow analysis, establishes whether values from untrusted methods and parameters may flow into security-sensitive operations. Taint analysis can detect many common vulnerabilities in Web applications, and so has attracted much attention from both the research community and industry. However, most static taint-analysis tools do not address critical requirements for an industrial-strength tool. Specifically, an industrial-strength tool must scale to large industrial Web applications, model essential Web-application code artifacts, and generate consumable reports for a wide range of attack vectors.

We have designed and implemented a static Taint Analysis for Java (TAJ) that meets the requirements of industry-level applications. TAJ can analyze applications of virtually any size, as it employs a set of techniques designed to produce useful answers given limited time and space. TAJ addresses a wide variety of attack vectors, with techniques to handle reflective calls, flow through containers, nested taint, and issues in generating useful reports. This paper provides a description of the algorithms comprising TAJ, evaluates TAJ against production-level benchmarks, and compares it with alternative solutions.
LiteRace
Authors: Marino Daniel , Musuvathi Madanlal , Narayanasamy Satish
Published: June 2009

Data races are one of the most common and subtle causes of pernicious concurrency bugs. Static techniques for preventing data races are overly conservative and do not scale well to large programs. Past research has produced several dynamic data race detectors that can be applied to large programs. They are precise in the sense that they only report actual data races. However, dynamic data race detectors incur a high performance overhead, slowing down a program's execution by an order of magnitude.

In this paper we present LiteRace, a very lightweight data race detector that samples and analyzes only selected portions of a program's execution. We show that it is possible to sample a multithreaded program at a low frequency, and yet, find infrequently occurring data races. We implemented LiteRace using Microsoft's Phoenix compiler. Our experiments with several Microsoft programs, Apache, and Firefox show that LiteRace is able to find more than 70% of data races by sampling less than 2% of memory accesses in a given program execution.
Analyzing recursive programs using a fixed-point calculus
Authors: La Torre Salvatore , Parthasarathy Madhusudan , Parlato Gennaro
Published: June 2009

We show that recursive programs where variables range over finite domains can be effectively and efficiently analyzed by describing the analysis algorithm using a formula in a fixed-point calculus. In contrast with programming in traditional languages, a fixed-point calculus serves as a high-level programming language to easily, correctly, and succinctly describe model-checking algorithms While there have been declarative high-level formalisms that have been proposed earlier for analysis problems (e.g., Datalog the fixed-point calculus we propose has the salient feature that it also allows
algorithmic
aspects to be specified.

We exhibit two classes of algorithms of symbolic (BDD-based) algorithms written using this framework-- one for checking for errors in sequential recursive Boolean programs, and the other to check for errors reachable within a bounded number of context-switches in a concurrent recursive Boolean program. Our formalization of these otherwise complex algorithms is extremely simple, and spans just a page of fixed-point formulae. Moreover, we implement these algorithms in a tool called
Getafix
which expresses algorithms as fixed-point formulae and evaluates them efficiently using a symbolic fixed-point solver called
Mucke
. The resulting model-checking tools are surprisingly efficient and are competitive in performance with mature existing tools that have been fine-tuned for these problems.
SoftBound
Authors: Nagarakatte Santosh , Zhao Jianzhou , Martin Milo M.K. , Zdancewic Steve
Published: June 2009

The serious bugs and security vulnerabilities facilitated by C/C++'s lack of bounds checking are well known, yet C and C++ remain in widespread use. Unfortunately, C's arbitrary pointer arithmetic, conflation of pointers and arrays, and programmer-visible memory layout make retrofitting C/C++ with spatial safety guarantees extremely challenging. Existing approaches suffer from incompleteness, have high runtime overhead, or require non-trivial changes to the C source code. Thus far, these deficiencies have prevented widespread adoption of such techniques.

This paper proposes SoftBound, a compile-time transformation for enforcing spatial safety of C. Inspired by HardBound, a previously proposed hardware-assisted approach, SoftBound similarly records base and bound information for every pointer as disjoint metadata. This decoupling enables SoftBound to provide spatial safety without requiring changes to C source code. Unlike HardBound, SoftBound is a software-only approach and performs metadata manipulation only when loading or storing pointer values. A formal proof shows that this is sufficient to provide spatial safety even in the presence of arbitrary casts. SoftBound's full checking mode provides complete spatial violation detection with 67% runtime overhead on average. To further reduce overheads, SoftBound has a store-only checking mode that successfully detects all the security vulnerabilities in a test suite at the cost of only 22% runtime overhead on average.
Control-flow refinement and progress invariants for bound analysis
Authors: Gulwani Sumit , Jain Sagar , Koskinen Eric
Published: June 2009

Symbolic complexity bounds help programmers understand the performance characteristics of their implementations. Existing work provides techniques for statically determining bounds of procedures with simple control-flow. However, procedures with nested loops or multiple paths through a single loop are challenging.

In this paper we describe two techniques,
control-flow refinement
and
progress invariants
, that together enable estimation of precise bounds for procedures with nested and multi-path loops. Control-flow refinement transforms a multi-path loop into a semantically equivalent code fragment with simpler loops by making the structure of path interleaving explicit. We show that this enables non-disjunctive invariant generation tools to find a bound on many procedures for which previous techniques were unable to prove termination. Progress invariants characterize relationships between consecutive states that can arise at a program location. We further present an algorithm that uses progress invariants to compute precise bounds for nested loops. The utility of these two techniques goes beyond our application to symbolic bound analysis. In particular, we discuss applications of control-flow refinement to proving safety properties that otherwise require disjunctive invariants.

We have applied our methodology to over 670,000 lines of code of a significant Microsoft product and were able to find symbolic bounds for 90% of the loops. We are not aware of any other published results that report experiences running a bound analysis on a real code-base.
A study of memory management for web-based applications on multicore processors
Authors: Inoue Hiroshi , Komatsu Hideaki , Nakatani Toshio
Published: June 2009

More and more server workloads are becoming Web-based. In these Web-based workloads, most of the memory objects are used only during one transaction. We study the effect of the memory management approaches on the performance of such Web-based applications on two modern multicore processors. In particular, using six PHP applications, we compare a general-purpose allocator (the default allocator of the PHP runtime) and a region-based allocator, which can reduce the cost of memory management by not supporting per-object free. The region-based allocator achieves better performance for all workloads on one processor core due to its smaller memory management cost. However, when using eight cores, the region-based allocator suffers from hidden costs of increased bus traffics and the performance is reduced for many workloads by as much as 27.2% compared to the default allocator. This is because the memory bandwidth tends to become a bottleneck in systems with multicore processors.

We propose a new memory management approach,
defrag-dodging
, to maximize the performance of the Web-based workloads on multicore processors. In our approach, we reduce the memory management cost by avoiding defragmentation overhead in the malloc and free functions during a transaction. We found that the transactions in Web-based applications are short enough to ignore heap fragmentation, and hence the costs of the defrag-mentation activities in existing general-purpose allocators outweigh their benefits. By comparing our approach against the region-based approach, we show that a per-object free capability can reduce bus traffic and achieve higher performance on multicore processors. We demonstrate that our defrag-dodging approach improves the performance of all the evaluated applications on both processors by up to 11.4% and 51.5% over the default allocator and the region-based allocator, respectively.
Chameleon
Authors: Shacham Ohad , Vechev Martin , Yahav Eran
Published: June 2009

Languages such as Java and C#, as well as scripting languages like Python, and Ruby, make extensive use of Collection classes. A collection implementation represents a fixed choice in the dimensions of operation time, space utilization, and synchronization. Using the collection in a manner not consistent with this fixed choice can cause significant performance degradation. In this paper, we present CHAMELEON, a low-overhead automatic tool that assists the programmer in choosing the appropriate collection implementation for her application. During program execution, CHAMELEON computes elaborate trace and heap-based metrics on collection behavior. These metrics are consumed on-thefly by a rules engine which outputs a list of suggested collection adaptation strategies. The tool can apply these corrective strategies automatically or present them to the programmer. We have implemented CHAMELEON on top of a IBM's J9 production JVM, and evaluated it over a small set of benchmarks. We show that for some applications, using CHAMELEON leads to a significant improvement of the memory footprint of the application.
Analytic Solutions of an Iterative Functional Differential Equation near Resonance
Authors: Liu Tongbo , Li Hong
Published: June 2009

We investigate the existence of analytic solutions of a class of second‐order differential equations involving iterates of the unknown function x′′(z) + cx′(z) = x(az + bx(z)) in the complex field ℂ. By reducing the equation with the Schröder transformation to the another functional differential equation without iteration of the unknown function λ2g′′(λz)g′(z) − λg′(λz)g′′(z) + = , we get its local invertible analytic solutions.
Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin
Authors: Angeli Renata , da Paz Nathalia V. N. , Maciel Jackeline C. , Araújo Flávia F. B. , Paiva Patrícia M. G. , Calazans Glícia M. T. , Valente Ana Paula , Almeida Fábio C. L. , Coelho Luana C. B. B. , Carvalho Luiz B. , Silva Maria da Paz C. , Correia Maria Tereza dos Santos
Published: June 2009

A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1,4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three‐step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G‐75, and ion exchange chromatography through a CM‐cellulose column.
Using Individual Spectra Simulation for the Study of Pole Figures Errors
Authors: Lychagina T. A. , Nikolayev D. I. , Wagner F.
Published: June 2009

Crystallographic texture is described by pole figures. In this paper, we continue to study experimental pole figure errors. In other words it can be named pole figure measurement errors. These errors are connected with the experimental procedure and do not depend on any further computations. In our previous works it was shown that the qualitative behaviour of pole figure measurement errors is similar to peak width determination errors. To check this conclusion a set of diffraction spectra were measured for Mg + 4.5%Al + 1%Zn sample on the spectrometer for quantitative texture analysis (SKAT) at FLNP, JINR, Dubna. Then we simulated the individual spectra and used these spectra for the pole figure extraction and the pole figure error determination. Such simulation enabled to confirm conclusions concerning the main role of the peak width determination error in the pole figure error. Additionally, we simulated individual spectra using model pole figures and extracted pole figures and pole figures errors from those spectra. For this case we also confirmed the same qualitative behaviour of pole figure measurement errors and peak width determination errors. The model pole figures were calculated on the basis of normal distributions.
Severe Facet Joint Arthrosis Caused C7/T1 Myelopathy: A Case Report
Authors: Aizawa Toshimi , Ozawa Hiroshi , Hoshikawa Takeshi , Kusakabe Takashi , Itoi Eiji
Published: June 2009

Cervical myelopathy is caused by degenerative processes of the spine including intervertebral disc herniation and posterior spur usually developing at C3/4 to C5/6. C7/T1 single level myelopathy is very rare because of the anatomical characteristics. Facet joint arthrosis can be a cause of cervical myelopathy but only a few cases have been reported. The authors report an extremely rare case of C7/T1 myelopathy caused by facet joint arthrosis. A 58-year-old male presented with hand and gait clumsiness. The radiological examinations revealed severe C7/T1 facet joint arthrosis with bony spur extending into the spinal canal, which compressed the spinal cord laterally. The T1 spinous process indicated nonunion of a “clay-shoveler's” fracture, which suggested that his cervico-thoracic spine had been frequently moved, and thus severe arthrosis had occurred in the facet joints. A right hemilaminectomy of C7 and C7/T1 facetectomy with single level spinal fusion led to complete neurological improvement.
Study of Ultrasound Transmission through an Immersed Glass Plate in view of Sonochemical Reactor Design Optimisation
Authors: Viennet R. , Hihn J.-Y. , Jeannot M. , Berriet R.
Published: June 2009

The purpose of this paper is to improve the design of an ultrasonic reactor for industrial applications in liquids, which consists of a double‐structured tank. This paper presents an experimental approach for studying ultrasonic transmission through an immersed glass plate. Several inclination angles, between 0 and 40∘, and several thicknesses have been investigated. Acoustic efficiency was determined using hydrophone measurements in different places in the reactor. A first reactor prototype was built and the optimised configuration defined was experimentally partially characterized and validated.
Spin Polarization and Exchange Interaction in a Diluted Magnetic Qunautm Dot
Authors: Peter A. John , Eucharista K. Lily Mary
Published: June 2009

The spin interaction energy of differentMn2+ions with and without an itinerant electron is evaluated for different dot radii. Magnetization is calculated for various concentrations ofMn2+ions with different dot sizes. Spin polaronic shifts are estimated using a mean field theory. The lowest binding energies of electrons in aCd1-xMnxTequantum dot are also calculated. Results are obtained forCd1−xinMnxinTe/Cd1−xoutMnxoutTestructures as a function of the dot radius variationally. It is found that (i) more number ofMn2+spins enhance the spin polaronic effect and it varies linearly with the concentration, (ii) spin polarization ofMn2+ions increases with the concentration for any dot radii, (iii) the magnetization of Mn subsystem increases with the concentration ofMn2+ions and this feature is predominant for smaller dots, and (iv) variation of increase in ionization energy is sharper for smaller dots with increase in concentration. These results are discussed with the available data in literature.
Some Properties of lp(A, X) Spaces
Authors: Fu Xiaohong , Li Songxiao
Published: June 2009

We provide a representation of elements of the space lp(A, X) for a locally convex space X and 1 ≤ p < ∞ and determine
its continuous dual for normed space X and 1 < p < ∞. In particular, we study the extension and characterization of isometries on lp(N, X) space, when X is a normed space with an unconditional basis and with a
symmetric norm. In addition, we give a simple proof of the main result
of G. Ding (2002).
Face to Face: Anthropometry‐Based Interactive Face Shape Modeling Using Model Priors
Authors: Zhang Yu , Prakash Edmond C.
Published: June 2009

This paper presents a new anthropometrics‐based method for generating realistic, controllable face models. Our method establishes an intuitive and efficient interface to facilitate procedures for interactive 3D face modeling and editing. It takes 3D face scans as examples in order to exploit the variations presented in the real faces of individuals. The system automatically learns a model prior from the data‐sets of example meshes of facial features using principal component analysis (PCA) and uses it to regulate the naturalness of synthesized faces. For each facial feature, we compute a set of anthropometric measurements to parameterize the example meshes into a measurement space. Using PCA coefficients as a compact shape representation, we formulate the face modeling problem in a scattered data interpolation framework which takes the user‐specified anthropometric parameters as input. Solving the interpolation problem in a reduced subspace allows us to generate a natural face shape that satisfies the user‐specified constraints. At runtime, the new face shape can be generated at an interactive rate. We demonstrate the utility of our method by presenting several applications, including analysis of facial features of subjects in different race groups, facial feature transfer, and adapting face models to a particular population group.
Approximate Analysis of MHD Squeeze Flow between Two Parallel Disks with Suction or Injection by Homotopy Perturbation Method
Authors: Domairry G. , Aziz A.
Published: June 2009

An analysis has been performed to study magneto‐hydrodynamic (MHD) squeeze flow between two parallel infinite disks where one disk is impermeable and the other is porous with either suction or injection of the fluid. We investigate the combined effect of inertia, electromagnetic forces, and suction or injection. With the introduction of a similarity transformation, the continuity and momentum equations governing the squeeze flow are reduced to a single, nonlinear, ordinary differential equation. An approximate solution of the equation subject to the appropriate boundary conditions is derived using the homotopy perturbation method (HPM) and compared with the direct numerical solution (NS). Results showing the effect of squeeze Reynolds number, Hartmann number and the suction/injection parameter on the axial and radial velocity distributions are presented and discussed. The approximate solution is found to be highly accurate for the ranges of parameters investigated. Because of its simplicity, versatility and high accuracy, the method can be applied to study linear and nonlinear boundary value problems arising in other engineering applications.
Biofouling Control in Cooling Water
Authors: Bott T. Reg
Published: June 2009

An important aspect of environmental engineering is the control of greenhouse gas emissions. Fossil fuel-fired power stations, for instance, represent a substantial contribution to this problem. Unless suitable steps are taken the accumulation of microbial deposits (biofouling) on the cooling water side of the steam condensers can reduce their efficiency and in consequence, the overall efficiency of power production, with an attendant increase in fuel consumption and henceCO2production. Biofouling control, therefore, is extremely important and can be exercised by chemical or physical techniques or a combination of both. The paper gives some examples of the effectiveness of different approaches to biofouling control.
Recurrent Fistula between Ileal Pouch and Vagina—Successful Treatment with a Gracilis Muscle Flap
Authors: Aydin Feride , Eisenberger Claus Ferdinand , Raffel Andreas , Rehders Alexander , Hosch Stefan Benedikt , Knoefel Wolfram Trudo
Published: June 2009

Fistulae between an ileal pouch and the vagina are an uncommon complication of ileal pouch-anal anastomosis following proctocolectomy and mucosectomy in patients with familial adenomatous polyposis coli. Several reports describe the successful use of muscle flaps to close recurrent pouch-vaginal-fistulae (PVF). However, series only contain small numbers and an optimal management has not yet been determined. We report the case of a 26-year old woman with a third recurrence of a PVF after proctocolectomy for treatment of familial adenomatous polyposis in October 2005. Because local approaches failed, definitive closure of the fistula was achieved by interposition of a gracilis muscle flap between the pouch-anal anastomosis and the vagina. The postoperative course was uneventful; the patient was discharged 7 days after surgery and remained free of recurrence and symptomatic complaints for 22 months now. The gracilis muscle flap proved to be an effective method in the treatment of recurrent PVF.
Challenges and Improvements in Distributed Software Development: A Systematic Review
Authors: Jiménez Miguel , Piattini Mario , Vizcaíno Aurora
Published: June 2009

Distributed Software Development (DSD) has recently evolved, resulting in an increase in the available literature. Organizations now have a tendency to make greater development efforts in more attractive zones. The main advantage of this lies in a greater availability of human resources in decentralized zones at less cost. There are, however, some disadvantages which are caused by the distance that separates the development teams. Coordination and communication become more difficult as the software components are sourced from different places, thus affecting project organization, project control, and product quality. New processes and tools are consequently necessary. This work presents the findings of a systematic review of the literature related to the challenges concerning Distributed Software Development, whose purpose is to identify the solutions and improvements proposed up to the present day.
Output Feedback Nonlinear -Tracking Control of a Nonminimum-Phase 2-DOF Underactuated Mechanical System
Authors: Aguilar Luis T.
Published: June 2009

Nonlinear synthesis is developed to solve the tracking control problem restricted to a two degrees-of-freedom (DOF) underactuated mechanical manipulator where position measurements are the only available information for feedback. A local controller is derived by means of a certain perturbation of the differential Riccati equations, appearing in solving the control problem for the linearized system. Stabilizability and detectability properties of the control system are thus ensured by the existence of the proper solutions of the unperturbed differential Riccati equations, and hence the proposed synthesis procedure obviates an extra verification work of these properties. Due to the nature of the approach, the resulting controller additionally yields the desired robustness properties against unknown but bounded external disturbances. The desired trajectory is centered at the upright position where the manipulator becomes a nonminimum-phase system. Simulation results made for a double pendulum show the effectiveness of the proposed controller.
Response of Patient-Derived Non-Small Cell Lung Cancer Xenografts to Classical and Targeted Therapies Is Not Related to Multidrug Resistance Markers
Authors: Rolff Jana , Dorn Cornelia , Merk Johannes , Fichtner Iduna
Published: June 2009

Tumor cells that are nonsensitive to anticancer drugs frequently have a multidrug resistant (MDR) phenotype. Many studies with cell lines and patient material have been done to investigate the impact of different resistance markers at protein and mRNA level in drug resistance but with contradictory outcome. In the present study, 26 well-characterised patient-derived non-small cell lung cancer xenografts were used. The known chemosensitivity to etoposide, carboplatin, gemcitabine, paclitaxel and erlotinib was compared to the protein and mRNA expression of BCRP, LRP, MDR1, and MRP1. Further, four of these xenografts were short-term treated to analyse possible regulation mechanisms after therapeutic interventions. We found a borderline correlation between thebcrpmRNA expression and the response of xenografts to etoposide. All other constitutive mRNA and protein expression levels were not correlated to any drug response and were not significantly influenced by a short term treatment. The present results indicate that the expression levels of MDR proteins and mRNA investigated do not play an important role in the chemoresistance of NSCLC in the in vivo situation.
Nanotechnology: A Tool for Improved Performance on Electrochemical Screen‐Printed (Bio)Sensors
Authors: Jubete Elena , Loaiza Oscar A. , Ochoteco Estibalitz , Pomposo Jose A. , Grande Hans , Rodríguez Javier
Published: June 2009

Screen‐printing technology is a low‐cost process, widely used in electronics production, especially in the fabrication of disposable electrodes for (bio)sensor applications. The pastes used for deposition of the successive layers are based on a polymeric binder with metallic dispersions or graphite, and can also contain functional materials such as cofactors, stabilizers and mediators. More recently metal nanoparticles, nanowires and carbon nanotubes have also been included either in these pastes or as a later stage on the working electrode. This review will summarize the use of nanomaterials to improve the electrochemical sensing capability of screen‐printed sensors. It will cover mainly disposable sensors and biosensors for biomedical interest and toxicity monitoring, compiling recent examples where several types of metallic and carbon‐based nanostructures are responsible for enhancing the performance of these devices.
The Determination of Bound Water in Waste Phosphatic Clay
Authors: Dham Mahir , Birgisson Bjorn , Boyd Andrew J.
Published: June 2009

Phosphatic clay is a by‐product of phosphate strip mining, particularly in Florida, USA. This waste material occupies about 100 000 acres of land which could be utilized for other causes. Thus, its use as an alternating cementing material for the addition into the mixing matrix of cement paste and concrete to yield higher strength would be profitable for both materials involved. But the biggest drawback faced is that the phosphatic clay possesses high water holding capacity. The water is thus not available for mixing purposes when added to cement paste and concrete and is thus known as bound water. It is therefore essential to determine the amount of bound water to phosphatic clay which shall not be available for the hydration reaction of cement in cement paste and concrete.
Association of Breast Cancer Stem Cells Identified by Aldehyde Dehydrogenase 1 Expression with Resistance to Sequential Paclitaxel and Epirubicin-Based Chemotherapy for Breast Cancers
Authors: Tanei Tomonori , Morimoto Koji , Shimazu Kenzo , Kim Seung Jin , Tanji Yoshio , Taguchi Tetsuya , Tamaki Yasuhiro , Noguchi Shinzaburo
Published: June 2009

Purpose: Breast cancer stem cells have been shown to be associated with resistance to chemotherapy in vitro, but their clinical significance remains to be clarified. The aim of this study was to investigate whether cancer stem cells were clinically significant for resistance to chemotherapy in human breast cancers.

Experimental Design: Primary breast cancer patients (n = 108) treated with neoadjuvant chemotherapy consisting of sequential paclitaxel and epirubicin-based chemotherapy were included in the study. Breast cancer stem cells were identified by immunohistochemical staining of CD44/CD24 and aldehyde dehydrogenase 1 (ALDH1) in tumor tissues obtained before and after neoadjuvant chemotherapy. CD44+/CD24− tumor cells or ALDH1-positive tumor cells were considered stem cells.

Results: Thirty (27.8%) patients achieved pathologic complete response (pCR). ALDH1-positive tumors were significantly associated with a low pCR rate (9.5% versus 32.2%; P = 0.037), but there was no significant association between CD44+/CD24− tumor cell proportions and pCR rates. Changes in the proportion of CD44+/CD24− or ALDH1-positive tumor cells before and after neoadjuvant chemotherapy were studied in 78 patients who did not achieve pCR. The proportion of ALDH1-positive tumor cells increased significantly (P < 0.001) after neoadjuvant chemotherapy, but that of CD44+/CD24− tumor cells did not.

Conclusions: Our findings suggest that breast cancer stem cells identified as ALDH1-positive, but not CD44+/CD24−, play a significant role in resistance to chemotherapy. ALDH1-positive thus seems to be a more significantly predictive marker than CD44+/CD24− for the identification of breast cancer stem cells in terms of resistance to chemotherapy.
Targeting DNA Methylation
Authors: Issa Jean-Pierre J. , Kantarjian Hagop M.
Published: June 2009

Two nucleoside inhibitors of DNA methylation, azacitidine and decitabine, are now standard of care for the treatment of the myelodysplastic syndrome, a deadly form of leukemia. These old drugs, developed as cytotoxic agents and nearly abandoned decades ago were resurrected by the renewed interest in DNA methylation. They have now provided proof of principle for epigenetic therapy, the final chapter in the long saga to provide legitimacy to the field of epigenetics in cancer. But challenges remain; we don't understand precisely how or why the drugs work or stop working after an initial response. Extending these promising findings to solid tumors faces substantial hurdles from drug uptake to clinical trial design. We do not know yet how to select patients for this therapy and how to move it from life extension to cure. The epigenetic potential of DNA methylation inhibitors may be limited by other epigenetic mechanisms that are also worth exploring as therapeutic targets. But the idea of stably changing gene expression in vivo has transformative potential in cancer therapy and beyond.
Cancer DNA Methylation: Molecular Mechanisms and Clinical Implications
Authors: McCabe Michael T. , Brandes Johann C. , Vertino Paula M.
Published: June 2009

DNA methylation plays a crucial role in the regulation of gene expression and chromatin organization within normal eukaryotic cells. In cancer, however, global patterns of DNA methylation are altered with global hypomethylation of repeat-rich intergenic regions and hypermethylation of a subset of CpG-dense gene-associated regions (CpG islands). Extensive research has revealed the cellular machinery that catalyzes DNA methylation, as well as several large protein complexes that mediate the transcriptional repression of hypermethylated genes. However, research is only just beginning to uncover the molecular mechanisms underlying the origins of cancer-specific DNA methylation. Herein, we present several recent advances regarding these mechanisms and discuss the relationship between histone modifications (i.e., H3K4me2/3, H4K16Ac, H3K9me2/3, H3K27me3, H4K20me3), chromatin-modifying enzymes (G9a, EZH2, hMOF, SUV4-20H), and aberrant DNA methylation. Additionally, the role played by inflammation, DNA damage, and miRNAs in the etiology of aberrant DNA methylation is considered. Finally, we discuss the clinical implications of aberrant DNA methylation and the utility of methylated biomarkers in cancer diagnosis and management.
Clinical Studies of Histone Deacetylase Inhibitors
Authors: Prince H. Miles , Bishton Mark J. , Harrison Simon J.
Published: June 2009

Over the last 5 years, a plethora of histone deacetylase inhibitors (HDACi) have been evaluated in clinical trials. These drugs have in common the ability to hyperacetylate both histone and nonhistone targets, resulting in a variety of effects on cancer cells, their microenvironment, and immune responses. To date, responses with single agent HDACi have been predominantly observed in advanced hematologic malignancies including T-cell lymphoma, Hodgkin lymphoma, and myeloid malignancies. Therefore, in this review we focus upon hematologic malignancies. Generally HDACi are well tolerated with the most common acute toxicities being fatigue, gastrointestinal, and transient cytopenias. Of note, few patients have been treated for prolonged periods of time and little is known about long-term toxicities. The use of the biomarker of histone hyperacetylation has been useful as a guide to target specificity, but generally does not predict for response and the search for more clinically relevant biomarkers must continue.
Rational Combinations Using HDAC Inhibitors
Authors: Bots Michael , Johnstone Ricky W.
Published: June 2009

In addition to well-characterized genetic abnormalities that lead to cancer onset and progression, it is now recognized that alterations to the epigenome may also play a significant role in oncogenesis. As a result, epigenetic-modulating agents such as histone deacetylase inhibitors (HDACi) have attracted enormous attention as anticancer drugs. In numerous in vitro and preclinical settings, these compounds have shown their vast potential as single agent anticancer therapies, but unfortunately equivalent responses have not always been observed in patients. Given the pleiotropic effects HDACi have on malignant cells, their true therapeutic potential most likely lies in combination with other anticancer drugs. In this review we will focus on the anticancer effects of HDACi when combined with other cancer therapeutics with an emphasis on those combinations based on a strong molecular rationale.
Epigenetic Modifiers: Basic Understanding and Clinical Development
Authors: Piekarz Richard L. , Bates Susan E.
Published: June 2009

More than 60 years after the first description of differentiation in cell culture and 40 years after the synthesis of 5-azacytidine, epigenetic therapies have been added to the anticancer armamentarium. DNA methyltransferase (DNMT) inhibitors such as 5-aza-2′-deoxycytidine or 5-azacytidine have been approved in myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML), whereas the histone deacetylase inhibitors (HDIs) including vorinostat, romidepsin, panobinostat, belinostat, and entinostat have been shown to be active in cutaneous and peripheral T-cell lymphoma. Although the range of malignancies in which monotherapy with DNMT inhibitors or HDIs are effective has been limited to date, the possibility remains that a broader spectrum of activity will be identified as combination studies are completed. Meanwhile, basic science has provided a steadily increasing understanding of the complexity of the epigenome, including the histone code and triggers for aberrant methylation, and their contribution to oncogenesis. As our basic understanding of the epigenetics of cancer increases, the number of potential therapeutic targets will also increase, offering more hope in the quest to treat cancer by normalizing the epigenome. This issue of CCR Focus is dedicated to understanding the clinical and translational aspects of epigenetics research.
Suppression of HER2/HER3-Mediated Growth of Breast Cancer Cells with Combinations of GDC-0941 PI3K Inhibitor, Trastuzumab, and Pertuzumab
Authors: Yao Evelyn , Zhou Wei , Lee-Hoeflich Si Tuen , Truong Tom , Haverty Peter M. , Eastham-Anderson Jeffrey , Lewin-Koh Nicholas , Gunter Bert , Belvin Marcia , Murray Lesley J. , Friedman Lori S. , Sliwkowski Mark X. , Hoeflich Klaus P.
Published: June 2009

Purpose: Oncogenic activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway is prevalent in breast cancer and has been associated with resistance to HER2 inhibitors in the clinic. We therefore investigated the combinatorial activity of GDC-0941, a novel class I PI3K inhibitor, with standard-of-care therapies for HER2-amplified breast cancer.

Experimental Design: Three-dimensional laminin-rich extracellular matrix cultures of human breast cancer cells were utilized to provide a physiologically relevant approach to analyze the efficacy and molecular mechanism of combination therapies ex vivo. Combination studies were done using GDC-0941 with trastuzumab (Herceptin), pertuzumab, lapatinib (Tykerb), and docetaxel, the principal therapeutic agents that are either approved or being evaluated for treatment of early HER2-positive breast cancer.

Results: Significant GDC-0941 activity (EC50 <1 μmol/L) was observed for >70% of breast cancer cell lines that were examined in three-dimensional laminin-rich extracellular matrix culture. Differential responsiveness to GDC-0941 as a single agent was observed for luminal breast cancer cells upon stimulation with the HER3 ligand, heregulin. Combined treatment of GDC-0941, trastuzumab, and pertuzumab resulted in growth inhibition, altered acinar morphology, and suppression of AKT mitogen-activated protein kinase (MAPK) / extracellular signed-regulated kinase (ERK) kinase and MEK effector signaling pathways for HER2-amplified cells in both normal and heregulin-supplemented media. The GDC-0941 and lapatinib combination further showed that inhibition of HER2 activity was essential for maximum combinatorial efficacy. PI3K inhibition also rendered HER2-amplified BT-474M1 cells and tumor xenografts more sensitive to docetaxel.

Conclusions: GDC-0941 is efficacious in preclinical models of breast cancer. The addition of GDC-0941 to HER2-directed treatment could augment clinical benefit in breast cancer patients.