bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical synthesis of novel biodegradable polyesters
Authors: Hori Y. , Takahashi Y. , Yamaguchi A. , Hagiwara T.
Published: October 2009

Distannoxane complexes catalyze the ring-opening polymerization of optically active β-butyrolactone (β-BL) to afford a high molecular weight poly(3-hydroxybutyrate). When 1-ethoxy-3-chlorotetrabutyldistannoxane was used as a catalyst (catalyst/(R)-β-BL = 1/8000 at 100 °C for 4 h), poly((R)-3-hydroxybutyrate) was obtained from (R)-β-BL in a yield of 99%. The copolymerizations of (R)-β-BL with racemic β-BL in several ratios gave corresponding stereocopolymers. The copolymerizations of (R)-β-BL with ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone, and L-lactide afforded novel optically active and biodegradable polyesters of high molecular weights, comprising (R)-3-hydroxybutyrate (3HB). The polymerization of (R)-β-BL catalyzed by the distannoxane complexes proceeded by bond breaking between the carbonyl carbon and oxygen atom of the lactone ring (acyl cleavage) with retention of the configuration and little or no racemization. Polymers that have over 80 mol% of the (R)-3HB unit were found to have almost the same degree of biodegradability as the copolyester of 3-hydroxybutyrate and 11% 3-hydroxyvalerate produced by the microbial method.Key words: distannoxane, ring-opening polymerization, poly(3-hydroxybutyrate), poly(3-hydroxyalkanoates), biodegradable polymer.
Physical properties of bacterial poly((R)-3-hydroxyalkanoates)
Authors: Koning Gertjan de
Published: October 2009

Poly((R)-3-hydroxyalkanoates) are bacterial storage polyesters, currently receiving much attention because of their potential application as biodegradable and biocompatible plastics. Methods and skills from both microbiology and polymer science can be used to manipulate these materials to make their physical properties meet the requirements for specific applications. The present paper reviews the physical properties of the most promising poly((R)-3-hydroxyalkanoates) as well as the opportunities offered by polymer technology to improve them, emphasizing the mechanical properties in relation to structure and processing.Key words: biopolymers, poly(hydroxyalkanoates), PHB, PHA.
A RECONFIGURABLE MODULAR ARCHITECTURE TO EXPLOIT WORD-LEVEL PARALLELISM
Authors: CARBALLO DANIEL J. , PARDINES INMACULADA , SANCHEZ-ELEZ MARCOS
Published: October 2009

Contemporary memory system design aims to achieve high performance and low energy consumption at a reasonable cost. To balance these requirements, we propose a modular reconfigurable architecture to design memories over FPGAs. The proposed memory system can be reconfigured taking into account: the number of words, the word size of the data, the number of physical memory banks and the number of ports of the banks. Different operating modes have been defined, each one implying a certain configuration for the memory system. Simulations of these modes show the performance of our reconfigurable memory in terms of timing and power consumption.
THE DIFFERENTIAL DIFFERENCE OPERATIONAL FLOATING AMPLIFIER: NEW CMOS REALIZATIONS AND APPLICATIONS
Authors: SOLIMAN EMAN A. , MAHMOUD SOLIMAN A.
Published: October 2009

This paper presents different novel CMOS realizations for the differential difference operational floating amplifier (DDOFA). The DDOFA was first introduced in Ref. 1 and was used to realize different analog circuits like integrators, filters and variable gain amplifiers. New CMOS realizations for the DDOFA are introduced in this literature. Furthermore the DDOFA is modified to realize a fully differential current conveyor (FDCC). Novel CMOS realizations of the FDCC are presented. The FDCC is used to realize second-order band pass–low-pass filter. Performance comparisons between the different realizations of the DDOFA and FDCC are given in this literature. PSPICE simulations of the overall proposed circuits are given using 0.25 μm CMOS Technology from TMSC MOSIS model and dual supply voltages of ±1.5 V.
APPLIED HIGH ENERGY QCD
Authors: KOPELIOVICH B. Z. , REZAEIAN A. H.
Published: October 2009

This review stresses the theoretical elements that underlie a wide range of phenomenological studies of high-energy QCD, which include both soft and hard processes. After a brief introduction to the basics of QCD, various aspects of QCD-based phenomenology are covered: color transparency, hadronization of color charges, Regge phenomenology, parton model, Bjorken scaling and its violation, DGLAP evolution equation, BFKL formalism, GLR-MQ evolution equation and saturation. In the last part of the review, we employ the light-cone dipole formalism to describe deep inelastic lepton scattering, Drell — Yan processes, direct photon production, diffraction, quark and gluon shadowing in nuclei, the Cronin effect and nuclear broadening.
THE GENERATION MODEL AND THE ORIGIN OF MASS
Authors: ROBSON B. A.
Published: October 2009

The origin of mass in the standard model of particle physics is discussed and some difficulties pointed out. An alternative model, the generation model, will be shown to lead to a different concept of mass: the mass of a body arises from the energy stored in the motion of its constituents, so that if a particle has mass, then it is composite. It is suggested that gravity is a residual interaction arising from the incomplete cancellation of the super-strong color interactions, which bind the fundamental constituents (rishons) of leptons and quarks.
MASS TERMS IN CP-CONSERVING WEINBERG THREE-HIGGS-DOUBLET MODEL
Authors: ZARRINKAMAR S. , HASSANABADI H. , RAJABI A. A.
Published: October 2009

By applying two transformations on the vacuum expectations of the Higgs fields, we show that instead of considering three nonvanishing complex fields, one can easily work with the real parts of two fields while CP conservation is assumed. Using this result, we next obtain the mass terms of CP-conserving Weinberg three-Higgs-doublet model (3HDM) which are essential in study of the spontaneous symmetry breaking and the Higgs mechanism.
S-WAVE BOTTOM BARYONS
Authors: GERASYUTA S. M. , MATSKEVICH E. E.
Published: October 2009

The masses of S-wave bottom baryons are calculated in the framework of coupled-channel formalism. The relativistic three-quark equations for the bottom baryons using the dispersion relation technique are found. The approximate solutions of these equations based on the extraction of leading singularities of the amplitude are obtained. The calculated mass values of S-wave bottom baryons are in good agreement with the experimental ones.
TWO-PHASE INTERACTIVE SATISFYING METHOD OF FUZZY MULTIPLE OBJECTIVE OPTIMIZATION WITH LINGUISTIC PREFERENCE
Authors: HU CHAOFANG , LI SHAOYUAN
Published: October 2009

This paper presents a two-phase interactive satisfying optimization method for fuzzy multiple objectives optimization with linguistic preference. This proposed approach utilizes the view that the more important objective has the higher desirable satisfying degree. The originally complex optimization problem is simplified and divided into two parts that are solved one by one. The decision maker can acquire satisfying solution of all the objectives under linguistic preference. Numerical example shows the efficiency, flexibility, and sensitivity of the proposed method.
MULTI-ASPECT MINING IN HEPATITIS DATA
Authors: OHSHIMA MUNEAKI , ZHONG NING , DONG JUZHEN , YOKOI HIDETO
Published: October 2009

When therapy using interferon medication for chronic hepatitis patients, various conceptual knowledge/rules will benefit for giving a treatment. The paper describes our work on cooperatively using various data mining agents including GDT-RS, learning with ordered information (LOI), and peculiarity oriented mining (POM) in a spiral discovery process with the multi-phase such as pre-processing, rule mining, and post-processing, for multi-aspect analysis of the hepatitis data and meta learning. GDT-RS is an inductive learning system for discovering decision rules. LOI discovers ordering rules and important features. POM finds peculiarity data/rules. Our methodology and experimental results show that the perspective of medical doctors will be changed from a single type of experimental data analysis towards a holistic view, by using our multi-aspect mining approach.
COMPLEXITY AND FAMILIARITY WITH COMPUTER ASSISTANCE WHEN MAKING ILL-STRUCTURED BUSINESS DECISIONS
Authors: MCLAIN DAVID L. , ALDAG RAMON J.
Published: October 2009

Using high-level tasks typical of managerial decisions, this experimental study examined the influence of computer assistance on solving ill-structured problems. Of specific interest were the influences of complex and simple assistance on decision performance and decision maker attitudes. Our findings suggest that performance and user attitudes can be enhanced by technology that provides clear and simple instruction in good problem-solving practices. However, when that technology adds a complex array of technical options and features, the assistance may fail to improve or/and may even diminish performance and damage user attitudes. Familiarization with such complex technology may not improve these outcomes. The findings regarding the relationship between assistance complexity and decision performance are consistent with those of studies that suggest complexity has a curvilinear influence on performance. When considering the application of technological assistance to ill-structured decision tasks, the complexity of the assistance should not be ignored.
ASSESSMENT OF NUCLEAR WASTE REPOSITORY OPTIONS USING THE ER APPROACH
Authors: XU DONG-LING
Published: October 2009

Two technically feasible nuclear waste repository options have been identified in Belgium. To select one for implementation, a study was carried out to compare the public perception and acceptance of the two options. In this paper, it is described how the study and selection process can be supported, and how the diversity and uncertainty in public opinions can be rationally modeled and analyzed by applying the Evidential Reasoning (ER) approach. The ER approach is a recent advancement for multi-criteria decision analysis (MCDA). By using belief decision matrices to model MCDA problems, both qualitative and quantitative information with various types of uncertainties can be taken into account in decision-making processes in a unified and logical format. Following an illustration of the ER approach and an outline of the selection problem, it is described how the ER approach can be used to model the problem, aggregate information, and facilitate sensitivity analysis. Some suggestions are made for future assessment studies.
EQUILIBRIUM AND NONEQUILIBRIUM MODELING OF YINYANG WUXING FOR DIAGNOSTIC DECISION SUPPORT IN TRADITIONAL CHINESE MEDICINE
Authors: ZHANG WEN-RAN , CHEN SU-SHING
Published: October 2009

Although the theory of YinYang WuXing (YYWX) or YinYang-5-Elements (subsystems of human body) has been a major analytical basis for Traditional Chinese Medicine (TCM) for thousands of years, the theory has been primarily empirical in nature without a formal mathematical or scientific foundation. Based on bipolar set theory, YinYang bipolar linear algebra is introduced and an equilibrium- or nonequilibrium-based computational model of YYWX is proposed. Nourishing and regulating relations are defined; YYWX dynamic equations are formulated; global and local equilibrium and nonequilibrium conditions are established and proved. Computer simulations of equilibrium and nonequilibrium processes show that the new approach provides a unique scientific basis for future research and development in herbal medicine, Qi (vital energy), QiGong, JingLuo (acupuncture channels), and acupuncture. A decision support system is prototyped and presented for diagnostic decision analysis in TCM. Furthermore, this work is expected to provide a basic YinYang cellular network architecture for modern scientific research in socioeconomics as well as in genomics, bioeconomics, metabolism, computational biology, aging, artificial intelligence, and biomedical engineering.
INDUCING DYNAMIC RULES OF NATIONS' COMPETITIVENESS FROM 2001–2005 MCI-WCY
Authors: LI HAN-LIN , KO YU-CHIEN
Published: October 2009

A nation's competitiveness has become more and more important in forming government strategy and business decision making. This study proposes an optimization model, instead of regression model or neural network model, to induce rules for dynamic nations' competitiveness based on the Major Competitiveness Indicators of the World Competitiveness Yearbook. Fourteen attributes are used to form the dynamic rules expressed in "IF…THEN…" forms. According to the induced rules, the strategic implications are suggested for various groups of nations to improve or to sustain their competitiveness.
Anatomical considerations in facial motion capture
Authors: Raga Elizabeth A. , Sumida Stuart S.
Published: October 2009

Facial performance capture has been enabled unquestionably by significant technological advances in three dimensional motion capture and modeling. Yet from a critical artistic perspective, the question remains: why do performances so generated frequently read as lifeless or "zombie-like"? While improvement in the density of collection and integration of data will undoubtedly refine the quality of the motion capture product, the anatomical answer to this artistic question goes beyond refinement of quasistatic simulation schemes and finite elements methods to address several basic principles of human facial anatomy, expression and ontogeny (development from juvenile to adult). The latter consideration is especially important in issues involving inter-individual scaling, because translation of facial performance onto characters of differing proportions presents one of the greatest challenges to the utility of motion capture.
A survey of BRDF models for computer graphics
Authors: Kurt Murat , Edwards Dave
Published: October 2009

To produce photo-realistic images in computer graphics, we must effectively describe the interactions between light and surfaces. In this paper, we focus on Bidirectional Reflectance Distribution Functions (BRDFs), which characterize these interactions. We survey on most BRDF representations introduced so far and we investigate their usage, importance and applications. We look at in detail their two important usages; in GPU-based real-time renderings and in renderings of metallic car paints.
Visualizing what lies inside
Authors: Correa Carlos D.
Published: October 2009

Medical imaging has given radiologists an ability that photography was not able to provide: it lets them see inside the human body. With the advent of 3D visualization systems, these images can be put together into crisp and impressive renderings of the human body from a variety of perspectives that were only dreamt of before, revolutionizing clinical practice.

Light transport models soon emerged to allow light interactions that, although not realistic in the physical sense, proved to be more effective for understanding the complex relationships among the anatomical structures. For instance, bone could be made semi-transparent to provide visibility of brain tissue. Skin could be removed altogether from an image to show only muscle or internal organs. However, soon it became evident that simply rendering these images in their raw form was no longer effective and the clear visualization of internal structures remains elusive.

The depiction of internal parts in the context of the enclosing space is a difficult problem that has occupied the mind of artists, illustrators and visualization practitioners. Despite the advances made in computer graphics for simulating the light transport in semi-transparent media, the problem of visualizing internal objects is no longer a rendering problem, but that of classification. Medical imaging technology obtains representations of anatomical structures via indirect ways, such as the response of tissue to X-rays or the alignment of electrons in a magnetic field. Therefore, the absence of semantic information prevents visualization practitioners from clearly marking up the regions that must be visualized. Without access to those regions, exploration becomes tedious and time-consuming. The predominant approach has been the use of transfer functions, or opacity mappings, which assign transparency properties to different intervals in the data. This method, however, does not guarantee that internal structures are visible. Other strategies must be used. In this article, I describe some visualization techniques that have emerged to obtain clear views of internal features in 3D volume data.
MPCP
Authors: Li Xiaolong , Yousefi'zadeh Homayoun
Published: October 2009

In the recent years, end-to-end feedback-based variants of TCP as well as VCP have emerged as practical alternatives of congestion control by requiring the use of only one or two ECN bits in the IP header. However, all such schemes suffer from a relatively low speed of convergence and exhibit a biased fairness behavior in moderate bandwidth high delay networks due to utilizing an insufficient amount of congestion feedback. In this paper, we propose a novel distributed ECN-based congestion control protocol to which we refer as Multi Packet Congestion Control Protocol (MPCP). In contrast to other alternatives, MPCP is able to relay a more precise congestion feedback yet preserve the utilization of the two ECN bits. MPCP distributes (extracts) congestion related information into (from) a series of n packets, thus allowing for a 2n-bit quantization of congestion measures with each packet carrying two of 2n bits in its ECN bits. We describe the design, implementation, and performance evaluation of MPCP through both simulations and experimental studies.
SIGCOMM
Authors: Davie Bruce
Published: October 2009

In my first month as SIGCOMM chair, I have been asked "what is your vision for SIGCOMM?", "can we make SIGCOMM more transparent?", and "will you write an article for CCR?". This article is an attempt to address all three of those questions.
A brief history of the internet
Authors: Leiner Barry M. , Cerf Vinton G. , Clark David D. , Kahn Robert E. , Kleinrock Leonard , Lynch Daniel C. , Postel Jon , Roberts Larry G. , Wolff Stephen
Published: October 2009

This paper was first published online by the Internet Society in December 20031 and is being re-published in ACM SIGCOMM Computer Communication Review because of its historic import. It was written at the urging of its primary editor, the late Barry Leiner. He felt that a factual rendering of the events and activities associated with the development of the early Internet would be a valuable contribution. The contributing authors did their best to incorporate only factual material into this document. There are sure to be many details that have not been captured in the body of the document but it remains one of the most accurate renderings of the early period of development available.
The workshop on active internet measurements (AIMS) report
Authors: claffy k. c. , Fomenkov Marina , Katz-Bassett Ethan , Beverly Robert , Cox Beverly A. , Luckie Matthew
Published: October 2009

Measuring the global Internet is a perpetually challenging task for technical, economic and policy reasons, which leaves scientists as well as policymakers navigating critical questions in their field with little if any empirical grounding. On February 12-13, 2009, CAIDA hosted the Workshop on Active Internet Measurements (AIMS) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops which provide a venue for researchers, operators, and policymakers to exchange ideas and perspectives. The two-day workshop included presentations, discussion after each presentation, and breakout sessions focused on how to increase potential and mitigate limitations of active measurements in the wide area Internet. We identified relevant stakeholders who may support and/or oppose measurement, and explored how collaborative solutions might maximize the benefit of research at minimal cost. This report describes the findings of the workshop, outlines open research problems identified by participants, and concludes with recommendations that can benefit both Internet science and communications policy. Slides from workshop presentations are available at http://www.caida.org/workshops/isma/0902/.
New frontiers in internet network management
Authors: Al-Shaer Ehab , Greenberg Albert , Kalmanek Charles , Maltz David A. , Ng T. S. Eugene , Xie Geoffrey G.
Published: October 2009

Network management represents an architectural gap in today's Internet [1]. Many problems with computer networks today, such as faults, misconfiguration, performance degradation, etc., are due to insufficient support for network management, and the problem takes on additional dimensions with the emerging programmable router paradigm. The Internet Network Management Workshop is working to build a community of researchers interested in solving the challenges of network management via a combination of bottoms-up analysis of data from existing networks and a top-down design of new architectures and approaches driven by that data. This editorial sets out some of the research challenges we see facing network management, and calls for participation in working to solve them.
Computing for global development
Authors: Toyama Kentaro , Ali Muneeb
Published: October 2009

CatePoverty and the associated su erings remain a global challenge, with over a billion people surviving on less than a dollar a day. Technology, applied appropriately, can help improve their lives. Despite some clear examples of technical research playing a key role in global development, there is a question that repeatedly arises in this area: can technologies for developing regions be considered a core area of computer science research? In this note, we examine some of the arguments on both sides of this question, deliberately avoid answering the question itself (for the lack of community consensus), and provide some suggestions for the case where the answer is in the affirmative.
Speculative N-Way barriers (abstract only)
Authors: Ziarek Lukasz , Jagannathan Suresh , Fluet Matthew , Acar Umut A.
Published: October 2009

Speculative execution is an important technique that has historically been used to extract concurrency from sequential programs. While techniques to support speculation work well when computations perform relatively simple actions (e.g., reads and writes to known locations), understanding speculation for multi-threaded programs in which threads may communicate and synchronize through multiple shared references is significantly more challenging, and is the focus of this paper.

We use as our reference point a simple higher-order concurrent language extended with an n-way barrier and a fork/join execution model. Our technique permits the expression guarded by the barrier to speculatively proceed before the barrier has been satisfied (i.e., before all threads that synchronize on that barrier have done so) and to have participating threads that would normally block on the barrier to speculatively proceed as well. Our solution formulates safety properties under which speculation is correct in a fork/join model, and per-synchronization basis.
Controlling chaos
Authors: Herhut Stephan , Scholz Sven-Bodo , Grelck Clemens
Published: October 2009

With the rising variety of hardware designs for multi-core systems, the effectiveness in exploiting implicit concurrency of programs plays a more vital role for programming such systems than ever before. We believe that a combination of a dataparallel approach with a declarative programming-style is up to that task: Data-parallel approaches are known to enable compilers to make efficient use of multi-processors without requiring low-level program annotations. Combining the dataparallel approach with a declarative programming-style guarantees semantic equivalence between sequential and concurrent executions of data parallel operations. Furthermore, the side-effect free setting and explicit model of dependencies enables compilers to maximise the size of the data-parallel program sections.

However, the strength of the rigidity of the declarative approach also constitutes its weakness: Being bound to observe all data dependencies categorically rules out the use of side-effecting operations within data-parallel sections. Not only does this limit the size of these regions in certain situations, but it may also hamper an effective workload distribution. Considering side effects such as plotting individual pixels of an image or output for debugging purposes, there are situations where a non-deterministic order of side-effects would not be considered harmful at all.

We propose a mechanism for enabling such non-determinism on the execution of side-effecting operations within data-parallel sections without sacrificing the side-effect free setting in general. Outside of the data-parallel sections we ensure singlethreading of side-effecting operations using uniqueness typing. Within data-parallel operations however we allow the sideeffecting operations of different threads to occur in any order, as long as effects of different threads are not interleaved. Furthermore, we still model the dependencies arising from the manipulated states within the data parallel sections. This measure preserves the explicitness of all data dependencies and therefore it preserves the transformational potential of any restructuring compiler.
Comparing the performance of concurrent linked-list implementations in Haskell
Authors: Sulzmann Martin , Lam Edmund S.L. , Marlow Simon
Published: October 2009

Haskell has a rich set of synchronization primitives for implementing shared-state concurrency abstractions, ranging from the very high level (Software Transactional Memory) to the very low level (mutable variables with atomic read-modify-write).

In this paper we perform a systematic comparison of these different concurrent programming models by using them to implement the same abstraction: a concurrent linked-list. Our results are somewhat surprising: there is a full two orders of magnitude difference in performance between the slowest and the fastest implementation. Our analysis of the performance results gives new insights into the relative performance of the programming models and their implementation.

Finally, we suggest the addition of a single primitive which in our experiments improves the performance of one of the STM-based implementations by more than a factor of 7.
A comparison of three delivery systems for teaching an information technology course
Authors: Boulet Marie-Michèle , Jebara Faouzi Ben , Bemmira Fathi , Boudreault Serge
Published: October 2009

An important aspect of the global, knowledge-based, technology-enabled economy is that organizations must invest in continuous training [4]. Managers, now exposed to concepts such as knowledge economy, organizational intelligence, learning organization, knowledge era, and organizational learning, [2, 3, 12], need to establish the optimum mix of continuous training activities to leverage organizational knowledge to its fullest potential. Several methods and models aimed at managing organizational knowledge at a macro level are now available [2, 3, 5, 6, 8, 9, 11]. But these methods don't address the micro level problem of planning and selecting continuous training activities while taking into account manager and employee preferences, and constraints such as budget or deliverables. The analysis of empirical data presented in this article incorporated factors, criteria, and weights into a model named Econof. Our findings provide managers with valuable tools to implement a continuous training management process aligned to organizational strategy---a step toward the development of knowledge management strategies.
Understanding ontological engineering
Authors: Devedzić Vladan
Published: October 2009

Ontological engineering has garnered increasing attention over the last few years, as researchers have recognized ontologies are not just for knowledge-based systems---all software needs models of the world, and hence can make use of ontologies at design time [1]. A recent survey of the field [4] suggests developers of practical AI systems may especially benefit from their use. This survey earmarked several application classes that benefit from using ontologies, including natural language processing, intelligent information retrieval (especially from the Internet), virtual organizations, and simulation and modeling.
Strategies for accelerating the worldwide adoption of e-commerce
Authors: Georgiou Christos J. , Stefaneas Petros S.
Published: October 2009

In recent years, many organizations have recognized the potential of e-commerce to improve profitability by increasing productivity and market penetration while reducing costs. But the vision of an electronically interconnected world requires the global adoption of e-commerce, not just in industrialized nations, but also in developing ones, where most of world's population lives. To successfully encourage the embrace of the Internet and e-commerce, one must carefully study the unique socioeconomic and cultural aspects of such nations. This article discusses ways to stimulate the worldwide adoption of e-commerce, based on our case study of Greece, a nation that has been slow to embrace Internet technologies.
Java distributed objects for numerical visualization in VisAD
Authors: Hibbard William , Rueden Curtis , Emmerson Steve , Rink Tom , Glowacki David , Whittaker Tom , Murray Don , Fulker David , Anderson John
Published: October 2009

The scientific world is evolving to require more collaboration among different institutions and disciplines. Understanding long-term changes in the Earth environment, for example, requires models that integrate disciplines such as meteorology, oceanography, hydrology (rivers and groundwater), soil science and geology. During the past 15 years, scientists have started sharing data using FTP and software on the Internet, but collaborative work and more routine data sharing require a new kind of scientific software.
Information quality benchmarks
Authors: Kahn Beverly K. , Strong Diane M. , Wang Richard Y.
Published: October 2009

Information quality (IQ) is an inexact science in terms of assessment and benchmarks. Although various aspects of quality and information have been investigated [1, 4, 6, 7, 9, 12], there is still a critical need for a methodology that assesses how well organizations develop information products and deliver information services to consumers. Benchmarks developed from such a methodology can help compare information quality across organizations, and provide a baseline for assessing IQ improvements.
The role of software processes and communication in offshore software development
Authors: Gopal Anandasivam , Mukhopadhyay Tridas , Krishnan Mayuram S.
Published: October 2009

Offshore software development is a new trend in the information technology (IT) outsourcing field, fueled by the globalization of IT and the improvement of telecommunication facilities. Countries such as India, Ireland, and Israel have established a significant presence in this market. In this article, we discuss how software processes affect offshore development projects. We use data from projects in India, and focus on three measures of project performance: effort, elapsed time, and software rework.
Gastrin induces the interaction between human mononuclear leukocytes and endothelial cells through the endothelial expression of P-selectin and VCAM-1
Authors: Ibiza Sales , Álvarez Ángeles , Romero Wilfredo , Barrachina Maria Dolores , Esplugues Juan Vicente , Calatayud Sara
Published: October 2009

Gastric mucosal inflammation is frequently associated with hypergastrinemia, and a correlation exists between the level of gastrin and degree of gastritis. We have previously observed that gastrin promotes leukocyte-endothelial interactions and contributes to Helicobacter -induced inflammation in the rat mesentery. In the present study, we aimed to evaluate a possible proinflammatory activity of gastrin in humans. The interaction between human leukocytes [U-937 cells, peripheral blood polymorphonuclear (PMN), and peripheral blood mononuclear (PBMC) cells] and human umbilical vein endothelial cells (HUVEC) was analyzed in static and dynamic conditions. The endothelial expression of adhesion molecules [P-selectin, E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule (VCAM)-1] was analyzed by flow cytometry and fluorescent microscopy screening. Gastrin increased the static adhesion of U-937 cells to HUVEC (1 h; 10−9 M: 122 ± 9%; 10−8 M: 143 ± 17%; 10−7 M: 162 ± 14% vs. control, all P < 0.05). Incubation of HUVEC with gastrin (4 h) also increased PBMC rolling (vehicle: 63 ± 12; 10−9 M: 109 ± 29; 10−8 M: 141 ± 24; 10−7 M: 261 ± 16 leukocytes/min, P < 0.05) and adhesion (vehicle: 3 ± 2, 10−9 M: 11 ± 4, 10−8 M: 17 ± 5, 10−7 M: 15 ± 5 leukocytes/mm2, all P < 0.05) in the parallel-plate flow chamber. Treatment of PBMC with gastrin had no effects. The cholecystokinin (CCK)-2 receptor antagonist (L-365,260, 10−7 M) prevented the effects of gastrin. P-selectin and VCAM-1 expression were enhanced by gastrin, and neutralizing antibodies against these molecules prevented PBMC rolling and adhesion. Gastrin did not affect the interactions between HUVEC and PMN. Gastrin induces interactions between human mononuclear leukocytes and endothelial cells through the activation of CCK-2 receptors and the enhancement of endothelial P-selectin and VCAM-1.
Role of p47phox in regulating Cdc42GAP, vimentin, and contraction in smooth muscle cells
Authors: Li Qing-Fen , Tang Dale D.
Published: October 2009

Cdc42GAP (GTPase activating protein) has been shown to regulate smooth muscle contraction as well as cell motility, adhesion, proliferation, and apoptosis. We have recently shown that Cdc42GAP activity is suppressed in smooth muscle cells during contractile activation, which is reversed by inhibitors of reactive oxygen species (ROS). Because p47phox, a regulatory subunit of NAD(P)H oxidase, has been implicated in smooth muscle signaling, we determined whether this subunit modulates Cdc42GAP activity in response to contractile stimulation. Transfection of smooth muscle cells with plasmids encoding short hairpin RNA (shRNA) against p47phox, but not plasmids for luciferase shRNA, inhibited the expression of p47phox. ROS production and the suppression of Cdc42GAP activity in response to stimulation with 5-hydroxytryptamine (5-HT) were attenuated in cells producing p47phox shRNA compared with cells producing luciferase shRNA. In contrast, the addition of hydrogen peroxide to p47phox-deficient cells suppressed the activity of Cdc42GAP. Furthermore, exposure to hydrogen peroxide led to a decrease in Cdc42GAP activity in an in vitro assay. Cdc42 activation, p21-activated kinase 1 (PAK1) phosphorylation at Thr-423 (an indication of PAK activation), and vimentin phosphorylation at Ser-56 in response to 5-HT activation were also attenuated in smooth muscle cells producing shRNA against p47phox. The knockdown of p47phox inhibited smooth muscle contraction during stimulation with 5-HT but not hydrogen peroxide. These results suggest that the p47phox subunit of NAD(P)H oxidase may mediate the agonist-induced GAP suppression by controlling ROS generation in smooth muscle cells during agonist stimulation. p47phox-regulated GAP affects smooth muscle contraction likely through the Cdc42/PAK1/vimentin pathway.
Characterizing the application of transcranial direct current stimulation in human pharyngeal motor cortex
Authors: Jefferson Samantha , Mistry Satish , Singh Salil , Rothwell John , Hamdy Shaheen
Published: October 2009

Transcranial direct current stimulation (tDCS) is a novel intervention that can modulate brain excitability in health and disease; however, little is known about its effects on bilaterally innervated systems such as pharyngeal motor cortex. Here, we assess the effects of differing doses of tDCS on the physiology of healthy human pharyngeal motor cortex as a prelude to designing a therapeutic intervention in dysphagic patients. Healthy subjects ( n = 17) underwent seven regimens of tDCS (anodal 10 min 1 mA, cathodal 10 min 1 mA, anodal 10 min 1.5 mA, cathodal 10 min 1.5 mA, anodal 20 min 1 mA, cathodal 20 min 1 mA, Sham) on separate days, in a double blind randomized order. Bihemispheric motor evoked potential (MEP) responses to single-pulse transcranial magnetic stimulation (TMS) as well as intracortical facilitation (ICF) and inhibition (ICI) were recorded using a swallowed pharyngeal catheter before and up to 60 min following the tDCS. Compared with sham, both 10 min 1.5 mA and 20 min 1 mA anodal stimulation induced increases in cortical excitability in the stimulated hemisphere (+44 ± 17% and +59 ± 16%, respectively; P < 0.005) whereas only 10 min 1.5 mA cathodal stimulation induced inhibition (−26 ± 4%, P = 0.02). There were neither contralateral hemisphere changes nor any evidence for ICI or ICF in driving the ipsilateral effects. In conclusion, anodal tDCS can alter pharyngeal motor cortex excitability in an intensity-dependent manner, with little evidence for transcallosal spread. Anodal stimulation may therefore provide a useful means of stimulating pharyngeal cortex and promoting recovery in dysphagic patients.
The normal mechanisms of pregnancy-induced liver growth are not maintained in mice lacking the bile acid sensor Fxr
Authors: Milona Alexandra , Owen Bryn M. , van Mil Saskia , Dormann Dirk , Mataki Chikage , Boudjelal Mohamed , Cairns William , Schoonjans Kristina , Milligan Stuart , Parker Malcolm , White Roger , Williamson Catherine
Published: October 2009

Rodents undergo gestational hepatomegaly to meet the increased metabolic demands on the maternal liver during pregnancy. This is an important physiological process, but the mechanisms and signals driving pregnancy-induced liver growth are not known. Here, we show that liver growth during pregnancy precedes maternal body weight gain, is proportional to fetal number, and is a result of hepatocyte hypertrophy associated with cell-cycle progression, polyploidy, and altered expression of cell-cycle regulators p53, Cyclin-D1, and p27. Because circulating reproductive hormones and bile acids are raised in normal pregnant women and can cause liver growth in rodents, these compounds are candidates for the signal driving gestational liver enlargement in rodents. Administration of pregnancy levels of reproductive hormones was not sufficient to cause liver growth, but mouse pregnancy was associated with increased serum bile acid levels. It is known that the bile acid sensor Fxr is required for normal recovery from partial hepatectomy, and we demonstrate that Fxr− /− mice undergo gestational liver growth by adaptive hepatocyte hyperplasia. This is the first identification of any component that is required to maintain the normal mechanisms of gestational hepatomegaly and also implicates Fxr in a physiologically normal process that involves control of the hepatocyte cell cycle. Understanding pregnancy-induced hepatocyte hypertrophy in mice could suggest mechanisms for safely increasing functional liver capacity in women during increased metabolic demand.
Estrogen replacement restores flow-induced vasodilation in coronary arterioles of aged and ovariectomized rats
Authors: LeBlanc Amanda J. , Reyes Rafael , Kang Lori S. , Dailey Robert A. , Stallone John N. , Moningka Natasha C. , Muller-Delp Judy M.
Published: October 2009

The risk for cardiovascular disease (CVD) increases with advancing age; however, the age at which CVD risk increases significantly is delayed by more than a decade in women compared with men. This cardioprotection, which women experience until menopause, is presumably due to the presence of ovarian hormones, in particular, estrogen. The purpose of this study was to determine how age and ovarian hormones affect flow-induced vasodilation in the coronary resistance vasculature. Coronary arterioles were isolated from young (6 mo), middle-aged (14 mo), and old (24 mo) intact, ovariectomized (OVX), and ovariectomized + estrogen replaced (OVE) female Fischer-344 rats to assess flow-induced vasodilation. Advancing age impaired flow-induced dilation of coronary arterioles (young: 50 ± 4 vs. old: 34 ± 6; % relaxation). Ovariectomy reduced flow-induced dilation in arterioles from young females, and estrogen replacement restored vasodilation to flow. In aged females, flow-induced vasodilation of arterioles was unaltered by OVX; however, estrogen replacement improved flow-induced dilation by ∼160%. The contribution of nitric oxide (NO) to flow-induced dilation, assessed by nitric oxide synthase (NOS) inhibition with NG-nitro-l-arginine methyl ester (l-NAME), declined with age. l-NAME did not alter flow-induced vasodilation in arterioles from OVX rats, regardless of age. In contrast, l-NAME reduced flow-induced vasodilation of arterioles from estrogen-replaced rats at all ages. These findings indicate that the age-induced decline of flow-induced, NO-mediated dilation in coronary arterioles of female rats is related, in part, to a loss of ovarian estrogen, and estrogen supplementation can improve flow-induced dilation, even at an advanced age.
Plasma hyperosmolality elevates the internal temperature threshold for active thermoregulatory vasodilation during heat stress in humans
Authors: Shibasaki Manabu , Aoki Ken , Morimoto Keiko , Johnson John M. , Takamata Akira
Published: October 2009

Plasma hyperosmolality delays the response in skin blood flow to heat stress by elevating the internal temperature threshold for cutaneous vasodilation. This elevation could be because of a delayed onset of cutaneous active vasodilation and/or to persistent cutaneous active vasoconstriction. Seven healthy men were infused with either hypertonic (3% NaCl) or isotonic (0.9% NaCl) saline and passively heated by immersing their lower legs in 42°C water for 60 min (room temperature, 28°C; relative humidity, 40%). Skin blood flow was monitored via laser-Doppler flowmetry at sites pretreated with bretylium tosylate (BT) to block sympathetic vasoconstriction selectively and at adjacent control sites. Plasma osmolality was increased by ∼13 mosmol/kgH2O following hypertonic saline infusion and was unchanged following isotonic saline infusion. The esophageal temperature (Tes) threshold for cutaneous vasodilation at untreated sites was significantly elevated in the hyperosmotic state (37.73 ± 0.11°C) relative to the isosmotic state (36.63 ± 0.12°C, P < 0.001). A similar elevation of the Tes threshold for cutaneous vasodilation was observed between osmotic conditions at the BT-treated sites (37.74 ± 0.18 vs. 36.67 ± 0.07°C, P < 0.001) as well as sweating. These results suggest that the hyperosmotically induced elevation of the internal temperature threshold for cutaneous vasodilation is due primarily to an elevation in the internal temperature threshold for the onset of active vasodilation, and not to an enhancement of vasoconstrictor activity.
Absorption kinetics are a key factor regulating postprandial protein metabolism in response to qualitative and quantitative variations in protein intake
Authors: Fouillet Hélène , Juillet Barbara , Gaudichon Claire , Mariotti François , Tomé Daniel , Bos Cécile
Published: October 2009

We have previously demonstrated that increasing the habitual protein intake widened the gap in nutritional quality between proteins through mechanisms that are not yet fully understood. We hypothesized that the differences in gastrointestinal kinetics between dietary proteins were an important factor affecting their differential response to an increased protein intake. To test this hypothesis, we built a 13-compartment model providing integrative insight into the sequential dynamics of meal nitrogen (Nm) absorption, splanchnic uptake, and metabolism, and subsequent peripheral transfer and deposition. The model was developed from data on postprandial Nm kinetics in certain accessible pools, obtained from subjects having ingested a15N-labeled milk or soy protein meal, after adaptation to normal (NP) or high (HP) protein diets. The faster absorption of Nm after soy vs. milk caused its earlier and stronger splanchnic delivery, which favored its local catabolic utilization (up to +30%) and limited its peripheral accretion (down to −20%). Nm absorption was also accelerated after HP vs. NP adaptation, and this kinetic effect accounted for most of the HP-induced increase (up to +20%) in splanchnic Nm catabolic use, and the decrease (down to −25%) in peripheral Nm anabolic utilization. The HP-induced acceleration in Nm absorption was more pronounced with soy than with milk, as were the HP effects on Nm regional metabolism. Our integrative approach identified Nm absorption kinetics, which exert a direct and lasting impact on Nm splanchnic catabolic use and peripheral delivery, as being critical in adaptation to both qualitative and quantitative changes in protein intake.
Ca2+cycling in cardiomyocytes from a high-performance reptile, the varanid lizard (Varanus exanthematicus)
Authors: Galli Gina L. J. , Warren Daniel E. , Shiels Holly A.
Published: October 2009

The varanid lizard possesses one of the largest aerobic capacities among reptiles with maximum rates of oxygen consumption that are twice that of other lizards of comparable sizes at the same temperature. To support this aerobic capacity, the varanid heart possesses morphological adaptations that allow the generation of high heart rates and blood pressures. Specializations in excitation-contraction coupling may also contribute to the varanids superior cardiovascular performance. Therefore, we investigated the electrophysiological properties of the l-type Ca2+channel and the Na+/Ca2+exchanger (NCX) and the contribution of the sarcoplasmic reticulum to the intracellular Ca2+transient (Δ[Ca2+]i) in varanid lizard ventricular myocytes. Additionally, we used confocal microscopy to visualize myocytes and make morphological measurements. Lizard ventricular myocytes were found to be spindle-shaped, lack T-tubules, and were ∼190 μm in length and 5–7 μm in width and depth. Cardiomyocytes had a small cell volume (∼2 pL), leading to a large surface area-to-volume ratio (18.5), typical of ectothermic vertebrates. The voltage sensitivity of the l-type Ca2+channel current ( ICa), steady-state activation and inactivation curves, and the time taken for recovery from inactivation were also similar to those measured in other reptiles and teleosts. However, transsarcolemmal Ca2+influx via reverse mode Na+/Ca2+exchange current was fourfold higher than most other ectotherms. Moreover, pharmacological inhibition of the sarcoplasmic reticulum led to a 40% reduction in the Δ[Ca2+]iamplitude, and slowed the time course of decay. In aggregate, our results suggest varanids have an enhanced capacity to transport Ca2+through the Na+/Ca2+exchanger, and sarcoplasmic reticulum suggesting specializations in excitation-contraction coupling may provide a means to support high cardiovascular performance.