bluuebunny/crossref_metadata_2025 huggingface dataset:
Disparities in Gastric Cancer Chemotherapy Between the East and West
Authors: Ohtsu Atsushi , Yoshida Shigeaki , Saijo Nagahiro
Published: May 2006

There are still remarkable disparities in the treatment of gastric cancer between the East and West. Treatment outcomes for this disease have improved in Japan due to early detection and surgical resection with systematic node dissections, such as D2, whereas gastric cancer remains a virulent disease in Western countries. Differences in the types of surgery and their outcomes affect how adjuvant trials are conducted and interpreted. Recent Western randomized trials demonstrated the significant survival benefit of adjuvant chemoradiotherapy or intensive combination chemotherapy. However, baseline surgical quality and outcomes were quite different from those in Japan, and Japanese surgical/medical oncologists have not accepted the Western results. Several disparities are also evident in the results of chemotherapy trials for advanced gastric cancer. Although similar results were obtained with randomized studies using older regimens, the interpretation of the results differed between Japan and other countries. A combination of cisplatin and fluorouracil was used as the reference arm in ongoing randomized trials in most countries, whereas single-agent fluorouracil or S-1 alone was used in Japanese trials. Two triplet regimens have already demonstrated significant prolongation of survival in Western studies. However, these benefits seem to be marginal and these regimens may be replaced by newer regimens, which will soon be available in Europe and Asia, where a total of 2,600 patients have been accrued. Although these disparities between regions must be overcome, it is time for both Eastern and Western investigators to pursue further benefits by incorporating new agents into treatment regimens.
Atom-transfer Reaction of Difluoroiodoacetate
Authors: Kitagawa Osamu , Miura Akihiko , Kobayashi Yoshiro , Taguchi Takeo
Published: May 2006

Radical chain reaction of difluoroiodoacetate with olefins catalyzed by copper provided atom-transfer products in good yields.
A New Efficient Chiral Catalyst System. Combined Use of Tin(II) Oxide, Trimethylsilyl Triflate and Chiral Diamine in the Asymmetric Aldol Reaction
Authors: Mukaiyama Teruaki , Uchiro Hiromi , Kobayashi Shu
Published: May 2006

The asymmetric aldol reaction between both achiral silyl enol ethers of thioesters and aldehydes is efficiently catalyzed by the use of a new catalyst system consisted of tin(II) oxide, trimethylsilyl triflate and a chiral diamine, to give the corresponding adducts in high yields with high diastereo- and enantioselectivities.
Conformational Properties of the Ethers of Hydroxy[24]metacyclophanes
Authors: Tsuge Akihiko , Sonoda Shuji , Mataka Shuntaro , Tashiro Masashi
Published: May 2006

Ethyl, propyl, isopropyl, butyl, pentyl and benzyl ethers of hydroxy[24]metacyclophanes were prepared. One of the conformers of the benzyl ether was confirmed to assume “cone” conformation by 1H NMR and X-ray analysis.
Unsymmetrically Substituted Ethylenedioxytetrathiafulvalenes
Authors: Mori Takehiko , Inokuchi Hiroo , Kini Aravinda M , Williams Jack M
Published: May 2006

Seven new electron donors, 4,5-ethylenedioxytetrathiafulvalenes where 4′,5′-substituents are trimethylenedithio, ethylenedithio, methylenedithio, 2-oxatrimethylenedithio, methylthio, hydrogen and methyl carboxylate, are prepared, and their electrochemical properties are investigated.
Synthesis of Poly(m-aniline) by Dehydrohalogenation of m-Chloroaniline
Authors: Yoshizawa Kazunari , Tanaka Kazuyoshi , Yamabe Tokio
Published: May 2006

A reddish-orange colored polymer was synthesized by catalytic dehydrohalogenation of m-chloroaniline. The polymer was confirmed to have a poly(m-aniline) structure which will be of our interest as a basic skeleton for ferromagnetic polymer.
A Novel Preparation of 2-Imino-1,3-thiazetidines from Carbon Disulfide, Dialkylcyanamide, and Benzylideneaniline under High Pressure
Authors: Tsuchiya Tohru , Yasumoto Masahiko , Shibuya Isao , Taguchi Yoichi , Yonemoto Katsumi , Goto Midori
Published: May 2006

At 800 MPa, 100 °C carbon disulfide, dialkylcyanamide and benzylideneaniline afford 2-dialkylthiocarbamoylimino-3,4-diphenyl-1,3-thiazetidine, the structure of which was determined by X-ray crystallography.
Multiple Interactions between Host Cyclodextrin and Guest Compound Assisting Asymmetrically Selective Reduction with NaBH4 in Aqueous Media
Authors: Hattori Kenjiro , Takahashi Keiko , Uematsu Masazumi , Sakai Naoki
Published: May 2006

In the presence of 6-mono-deoxy-amino-β-cyclodextrin, benzoylformic acid was enantioselectively reduced with sodium borohydride in aqueous solution. The dependence of the optical yield on pH, ionic strength, cyclohexanol and urea suggested that the concerted host–geust interaction arose from both hydrophobic and ionic interaction as well as hydrogen bonding.
Photocatalysis of Oligo(p-phenylene) Leading to Reductive Formation of Hydrogen and Ethanol from Triethylamine in Aqueous Organic Solvent
Authors: Matsuoka Shinjiro , Fujii Hiroyuki , Pac Chyongjin , Yanagida Shozo
Published: May 2006

Oligo(p-phenylene)s, i.e., p-terphenyl to p-sexiphenyl, catalyze photoreductive formation of H2 and ethanol in photolysis of aqueous solution of triethylamine under >290-nm irradiation in the presence of RuCl3. p-Terphenyl shows unusually effective photocatalysis for the formation of ethanol in aqueous tetrahydrofuran even without RuCl3.
A Novel Explanation for the Mechanism of Electrical Oscillation across a Liquid Membrane
Authors: Arai Kensuke , Kusu Fumiyo , Takamura Kiyoko
Published: May 2006

While studying electrical oscillation across a water-nitrobenzene-water liquid membrane, data that conflict with the explanation of Yoshikawa et al.1 were found. The mode of electrical oscillation across this membrane is quite similar to that between an organic and aqueous phase to which no detergent has previously been added. A new explanation is given for the mechanism of oscillation.
The First Synthesis of a Thermally Stable, Chiral Allenic Sulfoxide, (2-exo-Hydroxy-10-bornylsulfinyl)propa-1,2-diene
Authors: Arai Yoshitsugu , Takadoi Masanori , Kontani Tohru , Koizumi Toru , Shiro Motoo
Published: May 2006

The first synthesis of a thermally stable, chiral allenic suIfoxide (2-exo-hydroxy-10-bornylsulfinyl)propa-1,2-diene, has been achieved. It was revealed that the sulfoxide would be stabilized to racemization by an intramolecular hydrogen-bond.
1,3-Dipolar Cycloaddition Reaction of Bicyclic Aziridines with Cyclobutene. Synthesis of 1,2-Fused 4,5-Dihydro-1H-azepines
Authors: Matsumoto Kiyoshi , Ikemi Yukio , Takayama Chiaki , Aoyama Kinuyo , Uchida Takane
Published: May 2006

Reactions of 1,1a-dihydro-1,2-diarylazirino[1,2-a]quinoxalines with dimethyl 1-cyclobutene-1,2-dicarboxylate gave mixtures of the 1,2-fused-4,5-dihydro-1H-azepines along with the 1:1 adducts that were converted to the azepines upon treatment with Pd-C.
Oxygen-Induced Transmetallation of Organoboranes with Diphenyl Ditelluride
Authors: Abe Taro , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio
Published: May 2006

Diphenyl ditelluride rapidly reacted with trialkylboranes in the presence of oxygen to give alkyl phenyl tellurides in high yields. The facile reaction proceeds via a free-radical mechanism induced by a stoichiometrical.amount of oxygen. A combination of this transmetallation with hydroboration provides an alternative method for hydrotelluration of olefins.
Second Harmonic Generation of Multilayer Films of Aromatic Polymers Formed by Langmuir–Blodgett Method
Authors: Senoh Toshikazu , Sanui Kohei , Ogata Naoya
Published: May 2006

Ultra-thin films of poly(benzothiazole) (NO2-PBT) prepolymer which contained nitro groups were formed at air/water interface. Multilayer films of the NO2-PBT prepolymer which were made by Langmuir–Blodgett (LB) technique showed second harmonic generation (SHG). The SH light intensity of the NO2-PBT, however, which was obtained by heat treatment of the prepolymer was lower than that of the prepolymer.
A New and Facile Method for the Direct Preparation of α-Hydroxycarboxylic Acid Esters from α,β-Unsaturated Carboxylic Acid Esters with Molecular Oxygen and Phenylsilane Catalyzed by Bis(dipivaloylmethanato)manganese(II) Complex
Authors: Inoki Satoshi , Kato Koji , Isayama Shigeru , Mukaiyama Teruaki
Published: May 2006

In the presence of a catalytic amount of bis(dipivaloylmethanato)manganese(II) complex, the oxygenation of benzyl crotonate with molecular oxygen and phenylsilane proceeds smoothly under a mild condition to give benzyl 2-hydroxybutyrate in high yield. The reaction provides a new and convenient method for the direct preparation of various α-hydroxycarboxylic acid esters starting from α,β-unsaturated carboxylic acid esters. The influence of substituents of olefins on regioselectivity is also studied.
Intramolecular Electron-Transfer of Covalently-Linked Polypyridine Ruthenium(II)/Rhodium(III) Binuclear Complexes in the Excited State. Observation of the Marcus Inverted Region
Authors: Furue Masaoki , Hirata Masumi , Kinoshita Shuichi , Kushida Takashi , Kamachi Mikiharu
Published: May 2006

Ru(II)bpy2Mebpy-CH2CH(OH)CH2-MebpyRh(III)L2 (L = bpy. phen) (1) were newly synthesized. Intramolecular electron-transfer in excited 1 was studied with a time-correlated single photon counting method. In H2O, the excited Ru(II) complex exhibits a biexponential decay. The presence of a slow component suggests that the excited state can be repopulated by thermal activation from the Ru(III)–Rh(II) and the direct process to the ground state lies in the Marcus Inverted region.
Feasibility Studies on Amino-[2,3]Wittig Rearrangement. Silyl Triflate-Mediated [2,3]-Sigmatropic Rearrangement of α-Allylamino Esters
Authors: Murata Yoshinori , Nakai Takeshi
Published: May 2006

The feasibilities of both the LDA-induced and silyl triflate-mediated [2,3]-sigmatropic rearrangements of α-allylamino esters were studied. While the former enolate rearrangement does not proceed under the usual [2,3]Wittig conditions, the latter rearrangement is shown to proceed via the N-silylated ylide to provide the formal amino-[2,3]Wittig product with a high diastereoselectivity.
Oxidative Coupling Reaction of Acetylene Compounds in the Solid State
Authors: Toda Fumio , Tokumaru Yoshihisa
Published: May 2006

Oxidative coupling of acetylene compound with cupric salt in the solid state was found to proceed efficiently and selectively. The coupling reaction of α,ω-diacetylenes in the solid state gave the linear oligomers in contrast with the formation of the cyclic products in the solution reaction.
Non Conventional Fuel Resources in Rural India
Authors: Dixit G. , Dixit Savita , Tiwari Suchi
Published: May 2006

In India there is a shortage of energy resources. The conventional sources are incapable to mitigate this problem by providing sufficient amount of energy. The crisis is gradually becoming more acute particularly in the countryside thus hampering the economic growth. To deal with this problem some new strategies have been envisaged. Generation of energy to meet daily requirement from non-conventional sources is one of the steps in this regard. With the increasing popularity of biogas plants in rural as well as in urban areas of India, it has become essential to find various location specific organic substances that can be used as feed material in biogas plant. In this study we have concentrated on use of cow dung and water hyacinth as feed material in biogas plants. The objective of the study is to assess the suitability of using mixture of cow dung and water hyacinth as feed material in biogas plants. Attempt has been made to find out the optimum proportion of cow dung and water hyacinth. The 1:1 mixture of cow dung and water hyacinth is the optimum proportion as per the study conducted.
A Physical Computing Studio: Exploring Computational Artifacts and Environments
Authors: Camarata Ken , Gross Mark D , Do Ellen Yi-Luen
Published: May 2006

This paper describes a studio that explores interfaces for computationally enhanced artifacts and environments. The studio is designed as a traditional architectural design studio, fostering creative thinking and encouraging hands-on learning. It brings students from art, music, architecture, computer science, and engineering together into teams to design and build physical computing projects. The team's unusual mix of knowledge and experience allows for creative solutions. As a result, the studio has become a test bed for new and interesting ideas.
Spatial Cognition in Digital Cities
Authors: Chang Yu-Li
Published: May 2006

Today, digital cities are being developed all over the world. By using a city metaphor, digital cities integrate urban information and create public spaces. However, there are questions as to how to enter the new emerging digital cities, how humans perceive themselves in digital cities, and there are also issues of recognition of the digital city forms? This paper takes the idea of cognition in order to explore the structure of the new spatiality as cyberspace. By exploring the factors relating to human spatial cognition in physical space it is possible to interpret how humans perceive the spatial form of digital cities. By examining spatial experience in physical space, the interface of spatial cognition of interaction between digital cities and physical cities can be investigated. And by taking this approach, we propose an online prototype of a metaphor for a digital city.
Integrating Design and Construction with Wearable Computers
Authors: Elvin George
Published: May 2006

Wearable computers can help bridge the gap between design and construction. They can integrate these traditionally separate cultures by improving the flow of information between them. Using a wearable computer, design and construction personnel can now exchange design information quickly and continuously between the point of work on the construction site and the remote design office. The improved iteration between design and construction and much stronger connection between design personnel and construction site afforded by wearable computers may point the way to a new kind of integrated architectural process. In this study, the goal was to determine the value of wearable computers in integrating design and construction by measuring specific performance characteristics. The results include findings on productivity, rework and communication quality. They reveal that wearable computers can improve communication quality and reduce rework, but may have an initially negative impact on productivity. These findings suggest that wearable computers may play a key role in future building projects, helping to bridge the current divide between design and construction.
Improving ‘Objective’ Digital Images with Neuronal Processing: A Computational Approach
Authors: Mahalingam Ganapathy , Kavasseri Rajesh G.
Published: May 2006

This paper describes an experiment where an image recorded with a digital camera is processed using an electro-physiological model of a neuron. The luminosity level of each pixel of the source image is treated as the stimulus for an individual neuron, and the source image is transformed into a response image based on the processing behavior of the Hodgkin-Huxley neuronal model. It is seen that transformation of the image through neuronal processing yields (i) more evenly balanced levels of luminosity and (ii) a more ‘subjective’ rendering of the environment than what was photographed with the digital camera. The CCD (charge coupled device) – based digital camera reveals its limitation as a linear recording device that does not have a balanced dynamic range. The neuronal processing of the image adds non-linearity and a balanced range to the luminosity levels in the image, rendering it closer to a ‘subjective’ perception of the scene.
Component-Based Design: A Summary and Scheme for Implementation
Authors: Harfmann Anton C. , Bauser Paul J.
Published: May 2006

This paper summarizes the major advantages of component-based design as a paradigm for handling all design and construction information about a building at every stage of design. The paper reviews some of the current issues that plague the building design and construction industry. The component-based paradigm is reviewed as a model that reunites the fragmented building industry and as a solution for dealing with vast amounts of information that accretes during the design-construction process. Based on interviews with architects, engineers, contractors and fabricators as well as on-site documentation of construction we feature the design and construction of the main stair in the Rosenthal Center for Contemporary Art designed by Zaha Hadid as a specific case study to illustrate the viability of component-based design and to highlight the obstacles challenging its implementation.
Diffusion of Creative Design: Gatekeeping Effects
Authors: Sosa Ricardo , Gero John S.
Published: May 2006

A computational framework for design is presented to show that certain social structures can determine how novel solutions are created and spread. This paper suggests that creativity transcends the individual inasmuch as situational factors such as the role of gatekeepers can determine who is considered creative in a society.
Stylist and Scaleable – Vector Graphics for All on the Web
Authors: Ruffle Simon , Richens Paul
Published: May 2006

Raster graphics are ubiquitous on the web, but many architectural and engineering applications would be better served by vector techniques. Scalable Vector Graphics (SVG) is an emerging XML based vector graphics standard from the World Wide Web Consortium, but is not yet implemented in mainstream browsers. We describe a way of using the widely distributed Macromedia Flash Player to display SVG files. The resulting drawings are easy to rescale and restyle within the browser, offer superior printing, and many possibilities for advanced interaction and animation.
The Digital Media and New Technologies in Visual Arts Studio
Authors: Stipech Alfredo , Mantaras Guillermo
Published: May 2006

This studio dealt with the integration of Digital Media in both the Artistic-Creative and Teaching-Learning processes. The studio combines satellite and present classes during two months of intensive work, with an additional year of work via internet. We obtained successful results as measured by higher levels of knowledge acquisition and the development of perceptual skills. Those results were achieved despite noteworthy limitations in quantity and quality of electronic equipment available. This experience may be particularly important to people working in developing countries and/or in the area between visual arts and architecture.
Interfacing with the Real Space and its Performance
Authors: Malkawi Ali M. , Srinivasan Ravi S.
Published: May 2006

This paper presents an immersive gesture-recognition-based system to visualize the indoor thermal environment using Computational Fluid Dynamics (CFD). To enable efficient visualization of CFD in actual space, an Augmented Reality system was integrated with a CFD simulation engine. To facilitate efficient data manipulation of the simulated post-processed CFD data and to increase user control of the immersive environment, an intuitive method of Human-Computer Interaction (HCI) has been incorporated using gesture and speech recognition. While gesture recognition aids in transforming hand postures into command functions through forward kinematics and computation of hand segment positions and their joint angles, speech recognition allows better control of the data manipulation. This enabled real-time interactions between the users and simulated CFD results in actual space.
Interactive Rind Modeling for Architectural Design
Authors: Özener Ozan Önder , Akleman Ergun , Srinivasan Vinod
Published: May 2006

The paper presents a new modeling technique for architectural design. Rind modeling provides for the easy creation of surfaces resembling peeled and punctured rinds. We show how the method's two main steps of creation of a shell or crust and then opening holes in the crust by punching or peeling can be encapsulated into a real time semi-automatic interactive algorithm.

The rind modeling method allows us to develop a user-friendly tool for designers and architects. The new tool extends the abilities of polygonal modeling and allows designers to work on structured and consistent models for architectural design purposes. Rind modeling gives architects and designers a processing flexibility. It can be used in conceptual modeling during the early design phase. It can also be efficiently used for creating variety of shell structures for architectural design.
Structural Sketcher: Representing and Applying Well-Structured Graphic Representations in Early Design
Authors: Pranovich Slava , Achten Henri , de Vries Bauke , van Wijk Jack
Published: May 2006

Computational drawing support has the potential to improve design support in the early phase. Much work in this area is devoted to input of design information, manipulation, and presentation. Based on a review of current work, we note that among other things, digital drawing tools should be close to the conventions and techniques already used by architects. This is, in principle, possible by processing strokes in a more or less traditional sketch approach, or by offering specialised commands that provide a direct implementation of such conventions. The latter approach is covered by Structural Sketcher. A subset of drawing conventions developed earlier, called graphic units, is adopted within the system. In order to contribute to design support, the application of such graphic units should be fast and intuitive, and the definition of internal relationships should be quick and straightforward. For intuitive manipulation, Structural Sketcher incorporates the “paper and scissors” metaphor, and introduces a novel UI-concept called the KITE. To achieve an easy and fast maintenance of relationships, a graph based on anchor-points is built-up on the fly. Performance of the system has been tested on a quantitative and qualitative basis. The system shows the benefit that graphic units can bring to drawing support, and how these can be implemented. To conclude, limitations and further work are discussed.
Integrating Digital and Building Technologies: Towards a New Architectural Composite
Authors: Ataman Osman
Published: May 2006

This paper presents an ongoing research project about the development of the materials and fabrication techniques for a fundamentally new class of architectural composite. This type of composite, which is a representative example of an even broader class of smart architectural material, has the potential to change the design and function of an architectural structure or living environment. As of today, this kind of composite does not exist. Once completed, this will be the first technology on its own. We believe this study will lay the fundamental groundwork for a new paradigm in surface engineering that may be of considerable significance in architecture, building and construction industry, and materials science.
The Calabozo: Virtual Reconstruction of a Place Based on Testimonies
Authors: Massera Carmen Aroztegui
Published: May 2006

The objective the research reported here is to create a visualization of a place based on personal experiences. My research addresses this issue through a case study: the visualization of a women's political prison during the Uruguayan military dictatorship (1973–85). The proposed visualization is based on these women's personal experiences of the solitary confinement cell ( calabozo). Compared with their male counterpart, women's memories about prison have been traditionally relegated to a second level in Uruguay. The visualization aims to communicate these women's experiences of the calabozo through a video installation. This article first reviews relevant precedents to the case study and to virtual reconstructions and later describes the video installation.
In-Between and Through: Architecture and Complexity
Authors: de Almeida Clarissa Ribeiro Pereira , Pratschke Anja , Rocca Renata La
Published: May 2006

This paper draws on current research on complexity and design process in architecture and offers a proposal for how architects might bring complex thought to bear on the understanding of design process as a complex system, to understand architecture as a way of organizing events, and of organizing interaction. Our intention is to explore the hypothesis that the basic characteristics of complex systems – emergence, nonlinearity, self-organization, hologramaticity, and so forth – can function as effective tools for conceptualization that can usefully extend the understanding of the way architects think and act throughout the design process. To illustrate the discussions, we show how architects might bring complex thought inside a transdisciplinary design process by using models such as software engineering diagrams, and three-dimensional modeling network environments such as media to integrate, connect and ‘trans–act’.
Autopoiesis and Digital Design Theory: CAD Systems as Cognitive Instruments
Authors: Lyon Eduardo
Published: May 2006

In contrast to traditional models of design process fundamentally defined by the abstract manipulation of objects, this study recognizes that the resources available for rethinking architecture are to be found in a reformulation of its theory and practice. This reformation should be based on non-linear design processes in which dynamic emergence and invention take the place of a linear design process fixed on a particular object evolution. Advances in computation thinking and technology have stimulated the design and formulation of a large number of design software. Its elaboration supposes a new conceptualization of our discipline's knowledge, in a body of principles and regulations, which commands the artifact's design and its realization; therefore, it constitutes a preliminary datum for its comprehension, and thereby is of theoretical importance. Despite the continuous increment of power in computers and software capacities, the creative space of freedom defined by them acting as cognitive instruments remains almost unexplored. Therefore, we propose a change from a design knowledge based on objects to one focused on design as a network of processes. In addition, this study explores the concept of Distributed Cognition in order to redefine the use of digital tools in design process as Cognitive Instruments.
Design Innovation through Constraint Modeling
Authors: Kilian Axel
Published: May 2006

In this paper we describe how constraint modeling can support design innovation. Furthermore, we lay out how constraints are employed in the construction and exploration of a model's design space. We place the approach within the context of design exploration using computational and conceptual representations of design. A review of the literature reveals that geometric, topologic, functional, and quantitative constraints are those most commonly used. For each constraint type, an example is presented drawing from several workshops and research conducted by the author. The examples range from product design, to structural design, to fabrication issues in freeform geometry. Based on the case studies, we describe how the different types of constraints can be used as design drivers and help in the exploration of solution spaces. In conclusion, we identify the need for bidirectional exercising of constraints as the next challenge in design exploration and discuss how it is relevant in particular for cross domain design.
An mRNA sequence derived from a programmed frameshifting signal decreases codon discrimination during translation initiation
Authors: Raman Ana , Guarraia Carla , Taliaferro Dwayne , Stahl Guillaume , Farabaugh Philip J.
Published: May 2006

Sequences and structures in the mRNA can alter the accuracy of translation. In some cases, mRNA secondary structures like hairpin loops or pseudoknots can cause frequent errors of translational reading frame (programmed frameshifting) or misreading of termination codons as sense (nonsense readthrough). In other cases, the primary mRNA sequence stimulates the error probably by interacting with an element of the ribosome to interfere with error correction. One such primary mRNA sequence, the Ty3 stimulator, increases programmed +1 frameshifting 7.5 times in the yeast Saccharomyces cerevisiae. Here we show that this stimulator also increases the usage of non-AUG initiation codons in the bacterium Escherichia coli but not in S. cerevisiae. These data suggest that in E. coli, though not in yeast, an element of the ribosome's elongation accuracy mechanism ensures initiation accuracy.
Off-target effects by siRNA can induce toxic phenotype
Authors: Fedorov Yuriy , Anderson Emily M. , Birmingham Amanda , Reynolds Angela , Karpilow Jon , Robinson Kathryn , Leake Devin , Marshall William S. , Khvorova Anastasia
Published: May 2006

Although recent microarray studies have provided evidence of RNA interference (RNAi)-mediated off-target gene modulation, little is known about whether these changes induce observable phenotypic outcomes. Here we show that a fraction of randomly selected small inhibitory RNAs (siRNAs) can induce changes in cell viability in a target-independent fashion. The observed toxicity requires an intact RNAi pathway and can be eliminated by the addition of chemical modifications that reduce off-target effects. Furthermore, an analysis of toxic and nontoxic duplexes identifies a strong correlation between the toxicity and the presence of a 4-base-pair motif (UGGC) in the RISC-entering strand of toxic siRNA. This article provides further evidence of siRNA-induced off-target effects generating a measurable phenotype and also provides an example of how such undesirable phenotypes can be mitigated by addition of chemical modifications to the siRNA.
On Driver Anticipation, Two-Regime Flow, Fundamental Diagrams, and Kinematic-Wave Theory
Authors: Nelson Paul
Published: May 2006

The Cellular Automata (CA) Model CA-184a is introduced as a simplified traffic model that incorporates a rudimentary representation of driver anticipation. Simulations of single-loop and dual-loop acquisition of density-flow data upstream of a bottleneck are shown to display either a considerable similarity to density-flow data commonly so observed in vehicular traffic (i.e., two-regime flow, including an “inverted-lambda” shape), or a well-defined but clearly unrealistic density-flow relationship (fundamental diagram, FD), depending sensitively on the details of how the data are acquired. Simulation on a closed loop leads to stationary equilibria that provide a well-defined FD that is not manifestly unrealistic. The kinematic-wave model (KWM), employed with this closed-loop stationary equilibrium FD, provides results that agree arguably well, with some caveats, with the time-series data (upstream of the bottleneck) that generated the two-regime inverted-lambda FD. The source of the sensitivity of density-flow data to details of data acquisition is a strong correlation, in enqueued flow, between observed speeds and position relative to the bottleneck. This correlation, along with demand fluctuations near saturation, accounts for the departure from kinematic-wave predictions of simulated loop-based density-flow observations upstream of a bottleneck.
‘Research into Practice’: a model for healthcare management research?
Authors: Gollop Rose , Ketley Diane , Buchanan David , Whitby Elaine , Lamont Sharon , Jones Jane , Neath Annette , Fitzgerald Louise
Published: May 2006

English

Traditional modes of researching health service practice and policy have been criticised in terms of timeliness and relevance by potential users, and of poor uptake by researchers themselves. Newer models, based on principles of collaboration and integration, are being used in some healthcare settings, and there is evidence that these approaches help to bridge the gap that exists between ‘research’ and ‘practice’. This article describes the work of a small research team within the former NHS Modernisation Agency, appropriately named Research into Practice, and reflects on its experience of using collaborative and integrative approaches to its work.
Phosphorus fertilization in a phosphorus‐limited fen: effects of timing
Authors: Boeye Dirk , Verhagen Bart , van Haesebroeck Véronique , El‐Kahloun Mohssine
Published: May 2006

Abstract. Phosphorus availability in low P‐soils is primarily controlled by soil processes that are subject to seasonal fluctuation. There is evidence that summer drought causing low fen‐water levels induces temporal high P‐availability. We investigate here whether and how fen vegetation responds to P‐pulses at different times in the season. Plots were fertilized with equal P‐doses at three different times in the season. Four conclusions can be drawn from the experiment: 1. The vegetation is able to increase P‐uptake independent of the timing of fertilizer application; 2. Early‐season fertilization stimulates growth and increases P‐concentration in above‐ground tissue while late‐season fertilization does not stimulate growth but strongly increases above‐ground tissue concentration; 3. Timing effects cause differential species responses: the response of Carex demissa, a stress‐tolerant species, is truly independent of timing, while Juncus articulatus, a CSR‐type species (sensu Grime) profits more from early‐season fertilization; 4. Timing effects persist over several years. The differences between the experimental treatment and the events it aimed to simulate are discussed. We expect that higher frequencies of drought events, that may be induced by climate change, will cause a shift from nutrient‐stress tolerant towards stress‐tolerant‐competitor fen species.
Consequences of abandonment for a regional fen flora and mechanisms of successional change
Authors: Jensen Kai , Schrautzer Joachim
Published: May 2006

Abstract. Until the 1960s, species‐rich vegetation on minero‐trophic peaty soüs (fen sites) were characteristic of the alluvial plains in Schleswig‐Holstein (Northwest Germany). Today, many of these habitats undergo successional changes due to abandonment. Vegetation development after abandonment can be characterized as a sequence of different successional stages and described in terms of a successional model. Successional stage I includes grazed, mown and recently abandoned sites without dominants. Stages II and III are characterized by the dominance of highly competitive herbaceous species whüe stage IV consists of woody vegetation.

Ca. 3000 phytosociological relevés were assigned to the respective successional stages. Mean cover values were calculated for 250 species of the regional fen flora and assigned to successional categories according to their changes in cover in the successional series. According to our results 141 species decrease during succession, while 100 species were restricted to early successional stages and 85 species increased. Abandonment of all fen sites in Schleswig‐Holstein will probably lead to the regional loss of 23 species of the fen flora.

To identify mechanisms underlying successional change, the successional categories were correlated with life history traits and ecological requirements of the species. Results indicate that both light competition and limitation of sexual reproduction of small‐seeded species might play a major role in the decrease and extinction of species during succession.

Finally, conservation strategies for endangered species in a cultural landscape are discussed.
Restoration of alvar vegetation on Öland, Sweden
Authors: Rosén Ejvind , van der Maarel Eddy
Published: May 2006

Abstract.Alvars in the Baltic region, particularly on the Swedish islands of Öland and Gotland and in western Estonia, are well‐known for their plant species richness and extensive populations of rare species. Grasslands make up most of alvar vegetation. The extent of these grasslands decreases because of bush enchroachment which takes place in most alvars when traditional land use practice changes, notably when grazing is ceased. The main threat for the alvar grassland is formed by the rapid expansion ofJuniperus communis and Potentilla fruticosain dry and wet sites, respectively.

Applied research has been carried out during several years in order to develop plans for the restoration of alvar grassland. Thus it was shown that species richness in areas with a mixture of grassland and shrubland decreases in relation to the increased cover by shrubs. In the case ofJuniperusthere is a distinct drop in species number as soon as the cover exceeds 75‐80%, while the decrease is more gradual with increased cover ofPotentilla.The seed banks under dense stands of these shrubs only contain ca. 20% of the species found in dry and wet alvar meadows. This was confirmed by clearing experiments. Long‐term recordings have shown that establishment of juniper seedlings takes place mainly in half‐open areas between already existing junipers. Intermediate‐sized junipers expanded faster than old and big shrubs.Potentillashrubs recover fast from cutting or burning. After 2‐4 yr they have almost attained their former size. This recovery can be prevented when cattle grazing is introduced.

In the framework of a local alvar restoration project on Öland, covering 7000 ha, grazing regimes are re‐established, fences erected and large‐scale clearings carried out. Recently established juniper shrubs are being cleared, intermediate sized junipers (30‐50 yr old) are selectively removed while creating a mosaic landscape with high biological diversity. Older dense juniper stands are left alone or are only partly cleared.Potentillastands in moist areas are cut to create moist meadows which are breeding grounds for waders, and to establish corridors between remaining open areas.

Three items are discussed (1) the importance of the Stora Alvar area; (2) re‐introduction of grazing and (3) re‐introduction of species. The outstanding importance of the area regarding species richness and endemism should be recognized through a ‘golden list’ to be used along with red and blue lists.
Differences between European native and American invasive populations of Lythrum salicaria
Authors: Edwards Keith R. , Adams Michael S. , Kvet Jan
Published: May 2006

Abstract. We compared the demographic characteristics of native central‐European and invasive USA‐populations of Lythrum salicaria growing in similar habitats. Based on the ‘Evolution of increased competitive ability’ (EICA) hypothesis, we predicted that shoot density, height, and biomass, fertility, and fecundity would be less in the European populations due to greater loss of plant material caused by exposure to control agents. Shoot density was significantly greater in most USA‐populations, but shoot height and biomass were similar in invasive and native populations growing in similar habitats, especially in growing seasons with greater water availability. The number of fertile shoots was greater for invasive populations, except for those growing in sandy, nutrient‐poor substrates, while percent fertility did not differ between populations growing under similar field conditions. Fecundity was also similar for populations growing in nutrient‐poor and intermediate habitats, but was significantly greater in USA‐populations (89–103 seeds per fruit), compared to European populations (58–64 seeds per fruit), growing in nutrient‐rich habitats; seed predators were found in these European populations only.

Log‐linear analysis of transition frequency matrices showed that the growth of USA‐populations is different from European populations, but that habitat effect was strong. Population dynamics were similar for populations growing in nutrient‐poor habitats; location was of marginal importance only. USA‐populations responded differently from European populations growing in intermediate and nutrient‐rich habitats; differences were most pronounced between invasive (center of its North American distribution) and native populations growing in nutrient‐rich habitats.

The use of insect herbivores as biological control agents in North America will work best against L. salicaria populations growing in nutrient‐rich habitats in the center of its invasive distribution, but will be less effective against populations growing in other habitats or portions of its range. Other factors, including nutrient‐ or water availability, and climate, may be as important as herbivory in affecting invasive populations; these factors interact to control L. salicaria in a more complex manner than thought previously.
Quercus rugosa seedling dynamics in relation to its re‐introduction in a disturbed Mexican landscape
Authors: Bonfil C. , Soberón J.
Published: May 2006

Abstract. In order to define the ‘regeneration niche’ and then promote the re‐introduction of Quercus rugosa into a disturbed area we studied seed predation, germination, seedling survival and growth of this species at three different sites: the forest interior, the forest border and a disturbed site, along a disturbance gradient. Acorn removal on the ground was high at the sites, with higher removal rates from 25‐seed clusters than from 5‐ and 1‐seed clusters. More seeds were removed at the forest border than at the other two sites, although in all cases some seeds remained in the soil for periods long enough for them to germinate and produce seedlings. Seed germination and seedling establishment were more successful and similar in the forest interior and the forest border, and much less successful at the disturbed site, due to acorn desiccation. Seedling survival was strongly affected by site, with the highest survival at the forest border and the lowest survival at the disturbed site after a year.

The subsequent dry season, which was particularly harsh, caused a drop in survival both at the forest border and the disturbed site. In the former, a closer analysis revealed that partially shaded microsites enhanced survival, while in the latter overall survival was very low, with approximately 5 % of the seedlings surviving, compared to 50 % final survival at the other sites. There was a positive correlation between seed size and seedling survival at the forest border. The three size variables measured (seedling height, basal diameter and crown area) did not increase noticeably during the 20‐month study period at the forest interior, while growth still occurred at the forest border and the disturbed site. However, during the two dry seasons there were large drops in mean seedling height and crown area at the disturbed site, due to more frequent dieback, causing large variation in seedling size.

These results show that extensive re‐introduction of this species to the disturbed area will probably fail under present conditions, and that careful selection or duplication of microsites that mimic the partial shade of the forest border is a sound method for improving oak establishment at this site.
Temporal changes in spatial pattern of fine‐root mass and nutrient concentrations in Indian bamboo savanna
Authors: Tripathi S.K. , Singh K.P. , Singh P.K.
Published: May 2006

Abstract. Temporal variations in the spatial distribution of fine‐root mass and nutrient concentrations were studied in recently harvested and mature bamboo savanna sites in the dry tropical Vindhyan region in India. The soil block method and root‐free‐soil cages were used to investigate fine‐root dynamics. The mean annual fine‐root biomass was 596 and 690 g/m2 in harvested and mature sites, respectively. The fine‐root net production calculated by different methods ranged from 486 to 749 g m‐2 yr‐1 in the harvested site and 485 to 875 g m‐2 yr1 in the mature site. All fine‐root mass fractions decreased with increase in distance from the base of bamboo clumps, and the herb root mass showed the reverse trend. Bamboo fine roots were better developed in the 10 ‐ 20 cm soil depth and those of herbs in the upper 10 cm. The ingrowth of fine roots in root‐free‐soil cages showed maximum biomass accumulation during the rainy season (64.2 ‐ 69.9 g m‐2 mo‐1) and minimum in the summer (4.5 ‐ 7.5 g m‐2 mo‐1). The fine‐root nutrient concentrations were strongly related to their diameter. The fine‐root nutrient concentrations varied considerably in different seasons. The highest nutrient concentrations in all categories were recorded in summer followed by winter and rainy seasons. Nutrient concentrations in live roots were always greater than those found in dead roots in different diameter classes. We suggest the occurrence of nutrient retranslocation from senescent roots to surviving roots in bamboo savanna. Fine roots in the bamboo savanna increased as a function of N‐mineralization and nitrification rates. This tendency further increased after the harvest of bamboo, suggesting the crucial role of fine roots in the bamboo savanna after the harvesting of bamboo culms.
Factors controlling vegetation change in long‐term experiments designed to restore heathland in Breckland, UK
Authors: Marrs R.H. , Le Due M.G.
Published: May 2006

Abstract. This paper describes the vegetation change in an 18‐year experiment designed to test a range of control of Pteridium aquilinum (Pteridium) and heathland restoration treatments; cutting, asulam application and Calluna vulgar is seeding, in a range of combinations at Cavenham Heath in Breckland, UK between 1978 and 1996. Vegetation change was recorded in two Phases; in Phase I (1978‐1986) species biomass was sampled and in Phase II (1986‐1996) cover was measured. Initially, Calluna establishment was good in some treatments, especially where Calluna seed was added and Pteridium was controlled. Other plots developed either a grass‐heath flora dominated by Agrostis capillaris, Deschampsia flexuosa, Dicranum scoparium, Festuca ovina and Rumex acetosella or were dominated by clonal species such as Calamagrostis epigejos or Carex arenaria.

An unconstrained ordination showed significant vegetation change through time and that several treatments influenced the vegetation, especially those involving asulam application. When variation partitioning with constrained ordination was used a different explanation emerged. In Phase I the most important factors were the management treatments applied, elapsed time and spatial factors, with little overlap. In Phase II, elapsed time became irrelevant because the variation time explained overlapped that which could be explained by other variables. The most important of these were management treatments, spatial effects, weather, the amount of bare ground caused by disturbance and Pteridium litter cover (an index of Pteridium recovery). The implications of these results in interpreting vegetation change are discussed.
Vegetation mapping of the Great Fish River basin, South Africa: Integrating spatial and multi‐spectral remote sensing techniques
Authors: Tanser Frank , Palmer Anthony R.
Published: May 2006

Abstract. We present a remote sensing based vegetation mapping technique well suited to a heterogeneous, semi‐arid environment. 10 structural vegetation classes were identified and described on the ground. Using Landsat‐TM from two different seasons and a combination of three conventional classification techniques (including a multi‐temporal classification) we were unsuccessful in delineating all of the desired vegetation classes. We then employed a simple tex‐tural classification index, known as the Moving Standard Deviation Index (MSDI), that has been used to map degradation status. MSDI measures spatial variations in the landscape and is calculated by passing a 3 × 3 standard deviation filter across the Landsat‐TM red band. High MSDI values are associated with degraded or disturbed rangelands whilst low MSDI values are associated with undisturbed rangeland. A combination of two conventional multi‐spectral techniques and MSDI were used to produce a final vegetation classification at an accuracy of 84 %. MSDI successfully discriminated between two contrasting vegetation types of identical spectral properties and significantly strengthened the accuracy of the classification. We recommend the use of a tex‐tural index such as MSDI to supplement conventional vegetation classification techniques in heterogeneous, semi‐arid or arid environments.