bluuebunny/crossref_metadata_2025 huggingface dataset:
GROUPS WHOSE GEODESICS ARE LOCALLY TESTABLE
Authors: HERMILLER SUSAN , HOLT DEREK F. , REES SARAH
Published: August 2008

A regular set of words is (k-)locally testable if membership of a word in the set is determined by the nature of its subwords of some bounded length k. In this article we study groups for which the set of all geodesic words with respect to some generating set is (k-)locally testable, and we call such groups (k-)locally testable. We show that a group is 1-locally testable if and only if it is free abelian. We show that the class of (k-)locally testable groups is closed under taking finite direct products. We show also that a locally testable group has finitely many conjugacy classes of torsion elements.

Our work involved computer investigations of specific groups, for which purpose we implemented an algorithm in GAP to compute a finite state automaton with language equal to the set of all geodesics of a group (assuming that this language is regular), starting from a shortlex automatic structure. We provide a brief description of that algorithm.
GRADED POLYNOMIAL IDENTITIES FOR THE LIE ALGEBRA sl2(K)
Authors: KOSHLUKOV PLAMEN
Published: August 2008

The Lie algebra sl2(K) over a field K has a natural grading by ℤ2, the cyclic group of order 2. We describe the graded polynomial identities for this grading when the base field is infinite and of characteristic different from 2. We exhibit a basis of these identities that consists of one polynomial. In order to obtain this basis we employ methods and results from Invariant theory. As a by-product we obtain finite bases of the graded identities for sl2(K) graded by other groups such as ℤ2 × ℤ2 , and by the integers ℤ.
ON THE RECOGNITION OF THE SIMPLE GROUPS L7(3) AND L8(3) BY THE SPECTRUM
Authors: DARAFSHEH M. R.
Published: August 2008

In this paper we will prove that up to isomorphism there are two finite groups with the same spectrum as that of the simple group L7(3). For the group L8(3) we will prove that if G is a finite group with the same spectrum as that of L8(3), then G is isomorphic to the group L8(3).
A CHARACTERIZATION OF DEMORGAN BISEMIGROUP OF BINARY FUNCTIONS
Authors: PASHAZADEH J.
Published: August 2008

In this paper we define two binary operations and one unary operation on the set of all binary functions over the some set and find an abstract characterization of DeMorgan bisemigroup of binary functions.1
ALLEN–CAHN SYSTEMS WITH VOLUME CONSTRAINTS
Authors: GARCKE HARALD , NESTLER BRITTA , STINNER BJÖRN , WENDLER FRANK
Published: August 2008

We consider the evolution of a multi-phase system where the motion of the interfaces is driven by anisotropic curvature and some of the phases are subject to volume constraints. The dynamics of the phase boundaries is modeled by a system of Allen–Cahn type equations for phase field variables resulting from a gradient flow of an appropriate Ginzburg–Landau type energy. Several ideas are presented in order to guarantee the additional volume constraints. Numerical algorithms based on explicit finite difference methods are developed, and simulations are performed in order to study local minima of the system energy. Wulff shapes can be recovered, i.e. energy minimizing forms for anisotropic surface energies enclosing a given volume. Further applications range from foam structures or bubble clusters to tessellation problems in two and three space dimensions.
SHOCK LAYERS FOR TURBULENCE MODELS
Authors: BERTHON CHRISTOPHE , COQUEL FRÉDÉRIC
Published: August 2008

The present work is devoted to an extension of the Navier–Stokes equations where the fluid is governed by two independent pressure laws. Several turbulence models typically enter this framework. The striking novelty over the usual Navier–Stokes equations stems from the impossibility to recast equivalently the system of interest in full conservation form. Opposing to systems of conservation laws, where the end states of the viscous shock are completely characterized by jump relations, the lack of conservation implies the absence of jump relations. We analyze the traveling wave behaviors according to the ratio of viscosities, and we show that the traveling wave solutions of our system tend to the traveling wave solutions of a fully conservative system. This result is used to exhibit asymptotic expansions of the end states. Such an asymptotic behavior achieves a deep physical interpretation when illustrated in the case of compressible turbulent flows.
ON THE COUPLING OF 1D AND 3D DIFFUSION-REACTION EQUATIONS: APPLICATION TO TISSUE PERFUSION PROBLEMS
Authors: D'ANGELO C. , QUARTERONI A.
Published: August 2008

In this paper we consider the coupling between two diffusion-reaction problems, one taking place in a three-dimensional domain Ω, the other in a one-dimensional subdomain Λ. This coupled problem is the simplest model of fluid flow in a three-dimensional porous medium featuring fractures that can be described by one-dimensional manifolds. In particular this model can provide the basis for a multiscale analysis of blood flow through tissues, in which the capillary network is represented as a porous matrix, while the major blood vessels are described by thin tubular structures embedded into it: in this case, the model allows the computation of the 3D and 1D blood pressures respectively in the tissue and in the vessels.

The mathematical analysis of the problem requires non-standard tools, since the mass conservation condition at the interface between the porous medium and the one-dimensional manifold has to be taken into account by means of a measure term in the 3D equation. In particular, the 3D solution is singular on Λ. In this work, suitable weighted Sobolev spaces are introduced to handle this singularity: the well-posedness of the coupled problem is established in the proposed functional setting. An advantage of such an approach is that it provides a Hilbertian framework which may be used for the convergence analysis of finite element approximation schemes. The investigation of the numerical approximation will be the subject of a forthcoming work.
Webdunia: Beating the Downturn
Authors: Mitra Sumit , Agrawal Girish K.
Published: August 2008

Webdunia.com, one of the first Indian vernacular language portals, was launched in the heady days of the Internet boom in 1999. Born out of its owner-entrepreneur's dream of empowering his countrymen with information in their own vernacular language, Webdunia attracted venture funding focused on building traffic and hits to the portal. The meltdown in internet and portal business worldwide exposed the tenuous link between the venture capitalist's short-term view and the owner-manager's long-term objective in planning the future of Webdunia. Under testing conditions, tradeoffs between immediate revenue streams from rapidly expanding mobile telephone business in vernacular language and a much more slowly growing internet based business in e-governance, rural agricultural procurement and portal hits put the owner-entrepreneur in a dilemma. He was caught between the new partner's confidence in Webdunia's vernacular language computing and communications strength and revenue streams for immediate survival of the business. Synergistic linkages between transferable competencies and emerging growth opportunities in mobile telephony area promises short-term relief to the firm. However, in pursuing this path of empowering people in vernacular space, the owner-entrepreneur may take Webdunia away from leveraging internal competencies and assets in the language space including transliteration and voice and speech recognition where future sources of revenue could lie. This case is useful in assessing short-term and long-term directions of the firm and the dilemma of dealing with short-term perspectives of investors and shareholders.
Global Information Technology Company, Ltd
Authors: Leung Alicia , Wong Amy L. Y. , Young Michael N.
Published: August 2008

This case presents a scenario that pertains to the effective management of human resources in a Chinese cultural context where guanxi and face are of considerable importance. It depicts actual situations in detail, but the names of the organization and participants have been disguised at the request of the interviewees. The scenarios deal with issues of managerial appointments, promotion, husband-wife team in an organization, threat of resignation, effective leadership and achievement of subordinate respect and performance. Human resource management in China often requires a different approach from that espoused in the Western literature that currently dominates orthodox management theory. With China's growing economic power and the numerous foreign joint ventures in China, examining the cultural differences provides important insights for understanding the ways in which the norms and informal rules in general, and face and harmony in particular, function in Chinese organizations.
Managing Capacity at Sparsh Call Centre
Authors: Niranjan T. T. , Srivastava Samir K.
Published: August 2008

Bangalore based Sparsh Call Centre was set up as a subsidiary of the major telecom software company IP-Trinity, with ambitious plans of becoming a significant player in the booming BPO (business process outsourcing) space. Its strategy, in line with that of its parent group, was to focus on telecom related services. Sparsh began its operations in 2002 with its first client Alfa, a US based VOIP telephone service provider and had three other accounts and employed over 400 people. Financial performance had been lacklustre and top management including Kumar, Director (Operations) was carrying out a review. Operationally, everything appeared to be fine. People management was, to a great extent, managed by sophisticated workforce management software, supplemented by supervisory actions by managers.

This case is useful in highlighting the complexities of managing call centres and the unique people issues involved. This case illustrates that besides operational efficiencies, there is a need for a fit between strategy and scale of operations. In particular, high employee attrition can cause reduction in service quality as well as reduced capacity. Fast scale up of operations may be needed to make call centres economically viable. Cost effective innovative retention schemes may be needed to retain call centre staff to achieve this scale up.
Relationship Between Leadership Capability and Knowledge Management: A Measurement Approach
Authors: Suri Babu G. , Mohana Rao T. , Ahmed Salma , Gupta K. S.
Published: August 2008

The importance of leadership capability (LC) and knowledge management (KM) are well recognised in the popular and academic press to achieve competitive advantage. Although organisations are applying many skills and practices to address the problems for the achievement of competitive advantage, but unable to focus on the measurement and relationship aspects of LC and KM. Many organisations are succeeding and achieving their goals and targets generally with their human resource skills, and particularly with LC and KM. But there are no methodologies for their measurement aspects to plan for the required human resource with necessary competencies as per the desired organisational goals.

A research is carried out to develop a methodology for the measurement and relationship aspects of the LC and KM. As the main purpose of this paper is to investigate a relationship between LC and KM, a research study is carried out in: (i) development of process models for LC and KM, (ii) developed an instrument for measuring the LC and KM efforts and (iii) investigated for the relationship between LC and KM.

Based on the survey of 247 managers in the three major public sector undertakings, the LC and KM skills have been measured, and analysed for their relationship. The analysed data interprets that there is a positive correlation relationship between the LC and KM. Finally, this research limitations and implications have been examined.
The Export Decision and the Cognitive Limitation of the Managers
Authors: Santos-Álvarez Valle , Merino Teresa García
Published: August 2008

The object of this research is to present a theoretical model about the process of management perception of the factors which intervene in the export decision (strategic interest and accessibility to overseas markets). With that aim, the phases which constitute the perception process are identified — the selection of stimuli and interpretation — and the associated bias. Specifically, we identify two: bias by omission and bias by imprecise meaning. The use of different sources of information as well as the influence of the network of relations of the management allows us to investigate thoroughly the filters through which the informative stimuli pass which converge in the decision to export.
A Framework for Developing and Aligning a Knowledge Management Strategy
Authors: Swain Deborah E. , Ekionea Jean-Pierre Booto
Published: August 2008

Businesses today, including non-profits, recognise the need for knowledge management (KM). KM may require new strategies and goals before it can be implemented, or it can be aligned with current business strategies for quicker implementation. The framework presented here is for managers in companies and organisations to use to align their KM strategies with business strategies to improve performance involving financial growth, cost reduction and customer satisfaction. A study of three strategic types of organisations (defender, prospector, analyser) and interviews at a large corporation and a non-profit organisation suggests that the conceptual framework presented in this paper can be verified. More empirical evidence of alignment is planned, as organisations become more sophisticated users of KM.

The authors have been working for over three years on the taxonomy and conceptual framework for KM/BS Alignment (also known as KMSABS) and present a procedure for implementation in this paper. The KM/BS Alignment model involves concepts, actors, actions and processes. An important aspect of the methodology is for businesses and organisations to identify their strategic character to support appropriate interactions associated with knowledge. As shown in this paper, product and knowledge managers can affect goal alignment and interaction in an organisation if they implement change based on the suggested framework.
Kode viciousPride and prejudice (the
Vasa
)
Authors: Neville-Neil George
Published: August 2008

Navigating the well-traveled course of communication failure that often leads to engineering disasters.
Beyond keywords
Authors: Roussinov Dmitri , Fan Weiguo , Robles-Flores José
Published: August 2008

Beyond Google, emerging question-answering systems respond to natural-language queries.
An
O
(
n
2.75
) algorithm for incremental topological ordering
Authors: Ajwani Deepak , Friedrich Tobias , Meyer Ulrich
Published: August 2008

We present a simple algorithm which maintains the topological order of a directed acyclic graph (DAG) with
n
nodes, under an online edge insertion sequence, in
O
(
n
2.75
) time, independent of the number
m
of edges inserted. For dense DAGs, this is an improvement over the previous best result of
O
(min{
m
3/2
log
n
,
m
3/2
+
n
2
log
n
}) by Katriel and Bodlaender [2006]. We also provide an empirical comparison of our algorithm with other algorithms for incremental topological sorting.
Dense subgraph problems with output-density conditions
Authors: Suzuki Akiko , Tokuyama Takeshi
Published: August 2008

We consider the dense subgraph problem that extracts a subgraph, with a prescribed number of vertices, having the maximum number of edges (or total edge weight, in the weighted case) in a given graph. We give approximation algorithms with improved theoretical approximation ratios assuming that the density of the optimal output subgraph is high, where density is the ratio of number of edges (or sum of edge weights) to the number of edges in the clique on the same number of vertices. Moreover, we investigate the case where the input graph is bipartite and design a randomized pseudopolynomial time approximation scheme that can become a randomized PTAS, even if the size of the optimal output graph is comparatively small. This is a significant improvement in a theoretical sense, since no constant-ratio approximation algorithm was known previously if the output graph has
o
(
n
) vertices.
Deterministic conflict-free coloring for intervals
Authors: Bar-Noy Amotz , Cheilaris Panagiotis , Smorodinsky Shakhar
Published: August 2008

We investigate deterministic algorithms for a frequency assignment problem in cellular networks. The problem can be modeled as a special vertex coloring problem for hypergraphs: In every hyperedge there must exist a vertex with a color that occurs exactly once in the hyperedge (the conflict-free property). We concentrate on a special case of the problem, called conflict-free coloring for intervals. We introduce a hierarchy of four models for the aforesaid problem: (i) static, (ii) dynamic offline, (iii) dynamic online with absolute positions, and (iv) dynamic online with relative positions. In the dynamic offline model, we give a deterministic algorithm that uses at most log
3/2
n
+ 1 ≈ 1.71 log
2
n
colors and show inputs that force any algorithm to use at least 3 log
5
n
+ 1 ≈ 1.29 log
2
n
colors. For the online absolute-positions model, we give a deterministic algorithm that uses at most 3⌈log
3
n
⌉ ≈ 1.89 log
2
n
colors. To the best of our knowledge, this is the first deterministic online algorithm using
O
(log
n
) colors in a nontrivial online model. In the online relative-positions model, we resolve an open problem by showing a tight analysis on the number of colors used by the first-fit greedy online algorithm. We also consider conflict-free coloring only with respect to intervals that contain at least one of the two extreme points.
The relative worst order ratio applied to seat reservation
Authors: Boyar Joan , Medvedev Paul
Published: August 2008

The seat reservation problem is the problem of assigning passengers to seats on a train with
n
seats and
k
stations enroute in an online manner. The performance of algorithms for this problem is studied using the relative worst order ratio, a fairly new measure for the quality of online algorithms, which allows for direct comparisons between algorithms. This study has yielded new separations between algorithms. For example, for both variants of the problem considered, using the relative worst order ratio, First-Fit and Best-Fit are shown to be better than Worst-Fit.
Integrating Cross-Language Hierarchies and Its Application to Retrieving Relevant Documents
Authors: Fukumoto Fumiyo , Suzuki Yoshimi
Published: August 2008

Internet directories such as Yahoo! are an approach to improve
the efficacy and efficiency of Information Retrieval (IR) on the
Web, as pages (documents) are organized into hierarchical
categories, and similar pages are grouped together. Most of the
search engines on the Web service find documents that are assigned
to a single classification hierarchy. Categories in the hierarchy
are carefully defined by human experts and documents are well
organized. However, a single hierarchy in one language is often
insufficient to find all relevant material, as each hierarchy tends
to have some bias in both defining hierarchical structure and
classifying documents. Moreover, documents written in a language
other than the users native language often include large amounts of
information related to the users request. In this article, we
propose a method of integrating cross-language (CL) category
hierarchies, that is, Reuters 96 hierarchy and UDC code hierarchy
of Japanese by estimating category similarities. The method does
not simply merge two different hierarchies into one large hierarchy
but instead extracts sets of similar categories, where each element
of the sets is relevant with each other. It consists of three
steps. First, we classify documents from one hierarchy into
categories with another hierarchy using a cross-language text
classification (CLTC) technique, and extract category pairs of two
hierarchies. Next, we apply
Ç
2
statistics
to these pairs to obtain similar category pairs, and finally we
apply the generating function of the Apriori algorithm
(Apriori-Gen) to the category pairs, and find sets of similar
categories. Moreover, we examined whether integrating hierarchies
helps to support retrieval of documents with similar contents. The
retrieval results showed a 42.7% improvement over the baseline
nonhierarchy model, and a 21.6% improvement over a single
hierarchy.
An alternate design paradigm for low-power, low-cost, testable hybrid systems using scaled LTPS TFTs
Authors: Li Jing , Bansal Aditya , Ghosh Swarop , Roy Kaushik
Published: August 2008

This article presents a holistic hybrid design methodology for low-power, low-cost, testable digital designs using low-temperature polycrystalline-silicon thin-film transistors (LTPS TFTs). An alternate scaling rule under low thermal budget (due to flexible substrate) is developed to improve the performance of TFTs in the presence of process variation. We demonstrate that LTPS TFTs can be further optimized for ultralow-power subthreshold operation with performances comparable to contemporary single-crystal silicon-on-insulator (c-Si SOI) devices after process optimization. The optimized LTPS TFTs with high current drivability and less variability can comprise a promising low-cost option to augment Si CMOS technology, opening up a plethora of new hybrid 3D applications. We illustrate one such application: IC testing. Testing of complex VLSI systems is a prime concern due to design cost of DFT circuits, area/delay overheads, and poor test confidence. To harness the benefits of TFT technology, a novel low-power, process-tolerant, generic, and reconfigurable test structure designed using LTPS TFTs is proposed to reduce the test cost, as well as to improve diagnosability and verifiability, of complex VLSI systems. Due to proper optimization of TFT devices, the proposed test structure consumes low power but operates with reasonable performance. Furthermore, the test circuits do not consume any silicon area because they can be integrated on-chip using 3D technology. Since the test architecture is reconfigurable, this eliminates the need to redesign built-in-self-test (BIST) components that may vary from one processor generation to another. We have developed test structures using 200nm TFT devices and evaluated them on designs implemented in 130nm bulk CMOS. For circuit simulations, we have developed a SPICE-compatible model for TFT devices. The BIST components designed using the test structures operate at 0.8--4.3 GHz (compared to 8.2 GHz in bulk CMOS) with low power consumption. The enhanced scan cells partially implemented in TFT (3D hybrid design) consume ∼24% less power and ∼15--20% less area of Si die compared to conventional bulk-Si design (2D planar design), with minimal delay overhead.
Particle Aggregation
Authors: Burd Adrian B. , Jackson George A.
Published: August 2008

A basic problem in marine biogeochemistry is understanding material and elemental distributions and fluxes in the oceans, and a key part of this problem is understanding the processes that affect particulate material in the ocean. Aggregation of particulate material is a primary process because it alters the transport properties of particulate material and provides a mechanism for transferring material from the dissolved into the particulate pools. Aggregation theory not only provides a framework for understanding these processes, but it also provides a means for making predictions and has been successfully used to predict maximum particle concentrations in the oceans and the fate of diatom blooms (including those from iron fertilization), the size spectra of particles in the oceans, and the size distributions of trace metals. Here we review the basic theory involved, summarize recent developments, and explore unresolved issues.
Effects of Heat Treatments on the Electrocatalytic Activity of Pt-Ru/C for Methanol Oxidation
Authors: Godoi Denis R. M. , Perez Joelma , Villullas Hebe D.
Published: August 2008

The Pt-Ru/C materials of this study were prepared by a microemulsion method with fixed water to surfactant molar ratio and heat treated at low temperatures, to avoid changes in the average particle size, in different atmospheres. All samples were characterized by X-ray diffraction (XRD) and the mean crystallite size was estimated by using Scherrer's equation. Catalysts morphology was characterized by transmission electron microscopy (TEM). Average composition was obtained by energy- dispersive X-ray analysis (EDX). The general electrochemical behavior was evaluated by cyclic voltammetry in 0.5 M sulfuric acid and the electrocatalytic activity towards the oxidation of methanol was studied in 0.5 M methanol acid solutions by potential sweeps and chronoamperometry. Oxidation of adsorbed CO was used to estimate the electrochemical active area and to infer the surface properties.
The Influence of Methanol on Oxygen Reduction on Pt Nanoparticles Supported within PAMAM - G4OH Dendrimers as a Cathode for DMFCs
Authors: Escalante Ismailia L. , Ledesma-Garcia Janet , Chapman Thomas W. , Godínez Luis A.
Published: August 2008

In this work, generation-four hydroxyl-terminated poly(amidoamine) dendrimers (PAMAM-G4OH) were used as templates to produce Pt nanoparticles within their interior. Two methods were employed to synthesize the Pt nanocomposites and their immobilization onto oxidized glassy-carbon electrodes. Cyclic voltammetry (CV) and rotating-disk electrode (RDE) measurements were carried out to determine the electrocatalytic properties of these electrodes for oxygen reduction in aqueous acid media (0.5 M H2SO4) in the absence or presence of methanol. The results show that the dendrimer- incorporated Pt nanoparticles (Pt DENs) provide good electrocatalytic activity and selectivity for oxygen reduction in the presence of methanol. Simulation of a DMFC using Pt DENs on the cathode indicates that such a cell can deliver high power density based on the mass of Pt present.
Synthesis of Pd-Sn Nanoparticles by Using Ultrasonic Irradiation and their Electrocatalytic Activity for Oxygen Reduction
Authors: Kim Jandee , Park Jong-Eun , Momma Toshiyuki , Osaka Tetsuya
Published: August 2008

Nanoparticles of Pd-Sn were prepared under various conditions by applying ultrasonic irradiation. The Pd-Sn nanoparticles thus prepared were about 3-5 nm in diameter. The Pd in Pd-Sn nanoparticles was found to be mostly in the metallic state. The Pd-Sn nanoparticles have a better oxygen reduction reaction (ORR) activity than Pt and Pd nanoparticles in alkaline media. The mole ratio of Pd to Sn metal ions, their initial concentrations, the amount of ethanol, which served as the reducing agent for metal ions, and the amount of citric acid in the synthesizing solution were found to affect the size and distribution of obtained Pd-Sn nanoparticles. Therefore, the electrocatalytic activity for oxygen reduction was controlled by the above factors. Particularly, the amount of citric acid is important to control the surface modification on Pd-Sn particles to adjust the electrocatalytic activity for oxygen reduction.
Stabilization and Characterization of Pt Nanoparticles on HOPG
Authors: Halvorsen Helga C. , Bock Christina , MacDougall Barry , Wang Dashan
Published: August 2008

Platinum nano-catalysts are deposited, either by electrodeposition at constant potential or thermal decomposition, onto highly ordered pyrolytic graphite (HOPG). To help stabilize the nano-catalyst, the HOPG substrate is oxidized either by electrochemical methods or by ozone gas. The combination of two deposition techniques and two substrate oxidation techniques results in four different types of samples. As a point of reference, the particle morphology, activity towards oxidation of adsorbed carbon monoxide, and electrochemical stability of the four different types of samples are compared to a sample made by electrodeposition of Pt onto freshly cleaved HOPG. Of the four samples prepared, the combination of thermal reduction onto ozone oxidized HOPG was found to produce the most stable platinum nano-catalyst.
Electroless Deposition of Metals and Alloys for Micropelectronics, Nanoelectronics, Piezoengineering and Composites Fabrication
Authors: Khoperia Teimuraz N. , Zedginidze Tinatin I.
Published: August 2008

The results of investigations of the mechanism and kinetics of sensitization, activation and electroless deposition are presented. The proposed methods of metallization are used in industry. As a result, Au, Ag and Pd were adequately replaced with non-precious metals, usage of toxic substances was eliminated and the technology was significantly simplified.
The Relative Influences of Priors and Sensory Evidence on an Oculomotor Decision Variable During Perceptual Learning
Authors: Gold Joshua I. , Law Chi-Tat , Connolly Patrick , Bennur Sharath
Published: August 2008

Choice behavior on simple sensory-motor tasks can exhibit trial-to-trial dependencies. For perceptual tasks, these dependencies reflect the influence of prior trials on choices that are also guided by sensory evidence, which is often independent across trials. Here we show that the relative influences of prior trials and sensory evidence on choice behavior can be shaped by training, such that prior influences are strongest when perceptual sensitivity to the relevant sensory evidence is weakest and then decline steadily as sensitivity improves. We trained monkeys to decide the direction of random-dot motion and indicate their decision with an eye movement. We characterized sequential dependencies by relating current choices to weighted averages of prior choices. We then modeled behavior as a drift-diffusion process, in which the weighted average of prior choices provided an additive offset to a decision variable that integrated incoming motion evidence to govern choice. The average magnitude of offset within individual training sessions declined steadily as the quality of the integrated motion evidence increased over many months of training. The trial-by-trial magnitude of offset was correlated with signals related to developing commands that generate the oculomotor response but not with neural activity in either the middle temporal area, which represents information about the motion stimulus, or the lateral intraparietal area, which represents the sensory-motor conversion. The results suggest that training can shape the relative contributions of expectations based on prior trends and incoming sensory evidence to select and prepare visually guided actions.
Effect of starvation on transcriptomes of brain and liver in adult female zebrafish (Danio rerio)
Authors: Drew Robert E. , Rodnick Kenneth J. , Settles Matthew , Wacyk Jurij , Churchill Erin , Powell Madison S. , Hardy Ronald W. , Murdoch Gordon K. , Hill Rodney A. , Robison Barrie D.
Published: August 2008

We used microarray and quantitative real-time PCR (qRT-PCR) analyses in adult female zebrafish ( Danio rerio) to identify metabolic pathways regulated by starvation in the liver and brain. The transcriptome of whole zebrafish brain showed little response to 21 days of starvation. Only agouti-related protein 1 ( agrp1) significantly responded, with increased expression in brains of starved fish. In contrast, a 21-day period of starvation significantly downregulated 466 and upregulated 108 transcripts in the liver, indicating an overall decrease in metabolic activity, reduced lipid metabolism, protein biosynthesis, proteolysis, and cellular respiration, and increased gluconeogenesis. Starvation also regulated expression of many components of the unfolded protein response, the first such report in a species other than yeast ( Saccharomyces cerevisiae) and mice ( Mus musculus). The response of the zebrafish hepatic transcriptome to starvation was strikingly similar to that of rainbow trout ( Oncorhynchus mykiss) and less similar to mouse, while the response of common carp ( Cyprinus carpio) differed considerably from the other three species.
Rab8, a Vesicular Traffic Regulator, Is Involved in Dengue Virus Infection in HepG2 Cells
Authors: Xu Xiao-Feng , Chen Zong-Tao , Zhang Jun-Lei , Chen Wei , Wang Jia-Li , Tian Yan-Ping , Gao Na , An Jing
Published: August 2008

Objective: The pathogenesis of dengue virus (DV) has not been completely clarified. Rab8 regulates vesicular traffic from Golgi to plasma membrane where DV is matured and then delivered by exocytosis. In this study, involvement of Rab8 in DV serotype 2 (DV2) infection was investigated in HpeG2 cells. Methods: Distributions of Rab8 and DV2, and the number of infection cells were observed by immunostaining. HepG2Rab8AM and HepG2Rab8DN cells were constructed to stably express a constitutively active mutant of Rab8 and a dominant negative mutant, respectively, which were assessed by flow cytometry. Production of infectious virions and the amounts of DV2 entry were detected by standard plaque assay. Viral RNA replication was detected by real-time RT-PCR. Results: Rab8 showed high co-localization with DV2 in HpeG2 cells and the amount of DV antigen-positive cells decreased in HepG2Rab8AM and HepG2Rab8DN cells. Also, progeny virus released from those cells was drastically reduced. Infectious virions produced in cells were also significantly reduced, while the viral RNA replication was down-regulated by a different level. Furthermore, viral entry into those cells was reduced by about 80%. Conclusions: Our data suggest that the function of Rab8 is important for DV2 infection, and Rab8 may be involved in DV2 infection.
Urinary Infections due to Multi-Drug-Resistant Escherichia coli among Persons with HIV Disease at a Tertiary AIDS Care Centre in South India
Authors: Vignesh Ramachandran , Shankar Esaki Muthu , Murugavel Kailapuri G. , Kumarasamy Nagalingeswaran , Sekar Ramalingam , Irene Paulas , Solomon Suniti , Balakrishnan Pachamuthu
Published: August 2008

Background: While the spectrum of opportunistic infections due to HIV infection has been widely discussed, there are very limited data available in south India on certain incident infections especially urinary tract infections (UTI) in HIV-infected subjects. Methods: Bacterial aetiology of 350 symptomatic UTI in HIV-infected subjects and the drug resistance pattern of the Escherichia coli isolates tested between June 2005 and July 2007 at the YRG Centre for AIDS Research and Education, a tertiary HIV Referral Centre in Chennai has been described here. Results:E. coli was the most common etiological agent of UTI in HIV patients, followed by Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus spp. and Staphylococcus epidermidis. Twenty-nine E. coli isolates were multi-drug-resistant and 83.3% of the isolates were resistant to sulfamethoxazole-trimethoprim. Conclusions: Urinary pathogens in HIV-infected patients demonstrate high antimicrobial resistance and with majority of therapy for UTIs being empiric, constant updates of the aetiological agents and their drug susceptibility pattern would largely be beneficial to clinicians in choosing the right drug.
Stimmbezogene Lebensqualität: Struktur, Gültigkeit und Bedingungsfaktoren des deutschen Fragebogens
Authors: Schwanfelder Carla , Eysholdt Ulrich , Rosanowski Frank , Graessel Elmar
Published: August 2008

In this study, structure and validity of the German version of the Voice-Related Quality of Life (V-RQOL) questionnaire and its correlation to age, gender, and type of dysphonia (organic vs. functional) were assessed. Correlations of the V-RQOL result on the one hand and emotional and physical complaints on the other hand were investigated. Data were collected in 62 adult patients with dysphonia of benign origin and the following results were found: the German version of the V-RQOL questionnaire describes voice-related quality of life in one single value. Age, gender and type of dysphonia do not influence its result. Dysphonic patients present with an increased number of emotional and physical complaints when compared with normative values derived from the literature. However, not all of these complaints correlate with voice-related quality of life at a significant level.
Some Translations in Vascular Neurology
Authors: Bousser Marie-Germaine
Published: August 2008

‘Translation’ in medicine immediately suggests ‘translational research’, but there are many other varieties of ‘translation’. I have selected 4 translations in the field of vascular neurology in which I have been involved in different respects: (1) the translation of results from men to women, taking the example of aspirin which, in primary prevention, decreases the risk of myocardial infarction in men and the risk of cerebral infarction in women, the reason for this sex difference being so far unknown; (2) the ‘inverse translational research’, from bedside to bench, taking the example of the disease we have identified – CADASIL – and showing how the study of one patient and his family led to the identification of a gene, Notch3, so far unknown in humans and to the discovery of its key role in the physiology of vascular smooth muscle cells; (3) the translation from individual case reports to multidisciplinary trials taking the example of hemicraniectomy in malignant cerebral infarction and emphasizing the interest in such rare and severe conditions of pooling and reporting the results of randomized clinical trials before the results of individual trials, and (4) the translation from research to practice, emphasizing not the well-known ‘evidence to practice gap’ but the slippery slope of ‘lack of evidence to overpractice’, taking the example of patent foramen ovale closure in migraine.
Capecitabine and Cisplatin Combination Is an Active and Well-Tolerated Doublet in the Treatment of Metastatic Breast Carcinoma Patients Pretreated with Anthracycline and Taxanes
Authors: Öksüzoglu Berna , Abalı Huseyin , Hayran Mutlu , Yıldırım Nuriye , Budakoglu Burcin , Zengin Nurullah
Published: August 2008

Our aim was to evaluate the activity and toxicity of capecitabine and cisplatin (CapCisp) combination in anthracycline- and taxane-pretreated metastatic breast cancer patients. Thirty-three patients, 20–61 years of age (median 41), were included. They received Cap 2,000 mg/m2 on days 1–14 and Cisp 60 mg/m2 on day 1, repeated every 3 weeks. Twelve nonprogressive patients continued single-agent Cap therapy until progression or until intolerable toxicity after Cisp cessation. The disease control rate in 154 cycles was 81.8%: complete response 3.0% (n = 1), partial response 48.5% (n = 16) and stable disease 30.3% (n = 10). The median time to disease progression was 6.3 months (95% CI 3.8–8.8). The median overall survival was 11.5 months (95% CI 6.9–16.1). The only grade 3 toxicity was neutropenia, observed in 4 patients (12.1%). CapCisp has an encouraging anti-tumor activity with a low toxicity rate in anthracycline- and taxane-pretreated metastatic breast cancer patients.
Clinical Features of Mild Cognitive Impairment Differ in the Research and Tertiary Clinic Settings
Authors: Jicha G.A. , Abner E. , Schmitt F.A. , Cooper G.E. , Stiles N. , Hamon R. , Carr S. , Smith C.D. , Markesbery W.R.
Published: August 2008

Objective: Comparative analysis of subjects with mild cognitive impairment (MCI) diagnosed in a primary research setting and those seen in a tertiary care memory disorders clinic. Methods: Subjects who received a diagnosis of MCI between July 1, 2005, and December 31, 2006, in a longitudinal research study of normal cognition (n = 48) and patients diagnosed in a tertiary care referral clinic (n = 34) were evaluated using similar methodologies. Comparative analyses of detailed medical, neurological and neuropsychological data are presented. Results: The diagnosis of MCI was not accepted by 13 of 48 subjects (27%) classified as MCI in the primary research setting. Nondegenerative, potentially treatable causes of cognitive decline were found in 3 of 34 subjects (9%) seen in the tertiary referral clinic and in 11 of 35 subjects (31%) identified as MCI in the primary research setting (p = 0.02, Fisher’s exact test). MCI subjects identified in the primary research setting were older than those referred to the memory clinic (mean ± SD, 79.7 ± 7.0 vs. 71.5 ± 9.0 years, p < 0.0001, t test) and had more years of education (16.0 ± 3.2 vs. 13.6 ± 4.2 years, p < 0.01, t test). MCI subjects in the primary research setting appeared to be in a milder stage of disease, characterized by higher Mini-Mental State Examination scores (28.2 ± 1.8 vs. 25.7 ± 1.8, p < 0.0001), and a tendency towards single domain involvement, predominantly memory (mean number of domains involved, 1.0 vs. 2.5, p < 0.0001). More advanced stages of MCI, seen in the tertiary referral population, had additional involvement of attention (p < 0.0001, Fisher’s exact test) and visuospatial domains (p < 0.0002, Fisher’s exact test). Semiquantitative grading of hippocampal and medial temporal lobe atrophy did not differ between groups (p = 0.81, Mann-Whitney U test). Conclusions: The diagnosis of MCI may be unwelcome in naïve persons. Remedial causes of MCI should be actively investigated. Demographic and clinical characteristics of MCI differ between research subjects and patients referred to a tertiary care clinic.
Crosstalk between coagulation and inflammation during Dengue virus infection
Authors: Huerta-Zepeda Alejandra , Cabello-Gutiérrez Carlos , Cime-Castillo Jorge , Monroy-Martínez Verónica , Manjarrez-Zavala Maria Eugenia , Gutiérrez-Rodríguez Margarita , Izaguirre Raú , Ruiz-Ordaz Blanca
Published: August 2008

Dengue fever is the most prevalent viral disease transmitted by vectors (Aedes aegypti, Aedes albopictus) in worldwide. More than 100 million cases occur annually with a mortality rate of 5% and no safe vaccine is available. The pathogenesis of Dengue, where host and viral factors participate in the establishment of Dengue haemorrhagic fever (DHF) and Dengue shock syndrome (DSS) remains unresolved. Clinical observations have revealed significant abnormalities in coagulation and inflammation systems, with increased levels of tissue factor (TF) and the chemokine IL-8, correlating with the severity of the disease and implicating damage to endothelial vascular cells (EVC). Here we present novel insights concerning the crosstalk between the regulatory signaling pathways of the coagulation-inflammation processes, during Dengue virus (DV) infection of EVC. We found that DV up-regulates Protease Activated receptor type-1 (inflammation) and TF (coagulation) receptors, via the phosphorylation of p38 and ERK1/2 MAPKs, which favor the activation of NF-κB transcription factor. This induces pro-inflammatory (IL-8) or pro-adhesive (VCAM-1) gene expression which may lead to EVC activation. The elucidation of the basic principles that signal these processes has important implications for the design of new therapeutic strategies for DHF/DSS.
Reduced Ventrolateral fMRI Response during Observation of Emotional Gestures Related to the Degree of Dopaminergic Impairment in Parkinson Disease
Authors: Lotze Martin , Reimold Matthias , Heymans Ulrike , Laihinen Arto , Patt Marianne , Halsband Ulrike
Published: August 2008

Recent findings point to a perceptive impairment of emotional facial expressions in patients diagnosed with Parkinson disease (PD). In these patients, administration of dopamine can modulate emotional facial recognition. We used fMRI to investigate differences in the functional activation in response to emotional and nonemotional gestures between PD patients and age-matched healthy controls (HC). In addition, we used PET to evaluate the striatal dopamine transporter availability (DAT) with [11C]d-threo-methylphenidate in the patient group. Patients showed an average decrease to 26% in DAT when compared to age-corrected healthy references. Reduction in the DAT of the left putamen correlated not only with motor impairment but also with errors in emotional gesture recognition. In comparison to HC, PD patients showed a specific decrease in activation related to emotional gesture observation in the left ventrolateral prefrontal cortex (VLPFC) and the right superior temporal sulcus. Moreover, the less DAT present in the left putamen, the lower the activation in the left VLPFC. We conclude that a loss of dopaminergic neurotransmission in the putamen results in a reduction of ventrolateral prefrontal access involved in the recognition of emotional gestures.
Sequence Learning is Preserved in Individuals with Cerebellar Degeneration when the Movements are Directly Cued
Authors: Spencer Rebecca M. C. , Ivry Richard B.
Published: August 2008

Cerebellar pathology is associated with impairments on a range of motor learning tasks including sequence learning. However, various lines of evidence are at odds with the idea that the cerebellum plays a central role in the associative processes underlying sequence learning. Behavioral studies indicate that sequence learning, at least with short periods of practice, involves the establishment of effector-independent, abstract spatial associations, a form of representation not associated with cerebellar function. Moreover, neuroimaging studies have failed to identify learning-related changes within the cerebellum. We hypothesize that the cerebellar contribution to sequence learning may be indirect, related to the maintenance of stimulus–response associations in working memory, rather than through processes directly involved in the formation of sequential predictions. Consistent with this hypothesis, individuals with cerebellar pathology were impaired in learning movement sequences when the task involved a demanding stimulus–response translation. When this translation process was eliminated by having the stimuli directly indicate the response location, the cerebellar ataxia group demonstrated normal sequence learning. This dissociation provides an important constraint on the functional domain of the cerebellum in motor learning.
Response-selection Conflict Contributes to Inhibition of Return
Authors: Prime David J. , Jolicoeur Pierre
Published: August 2008

Here we examined the relationship between inhibition of return (IOR) and response-selection conflict. In two go/no-go and spatial-cueing experiments, we measured the amplitude of the fronto-central N2 event-related potential component to estimate the degree of response-selection conflict for validly cued and invalidly cued targets. When the probability of a go target was high (Experiment 1), both the amplitude of the N2 elicited on no-go trials and the number of false alarm errors were greater on invalid-cue than on valid-cue trials. When the probability of a go target was low (Experiment 2), neither of these effects was observed and the magnitude of the IOR effect was greatly reduced. These results show that a relative response bias toward responding on invalid-cue trials contributes to the IOR reaction time effect when the required response is prepotent.