bluuebunny/crossref_metadata_2025 huggingface dataset:
Control variates for screening, selection, and estimation of the best
Authors: Nelson Barry L. , Staum Jeremy
Published: May 2006

Ranking and selection procedures (R&S) were developed by statisticians to search for the best among a small collection of populations or treatments, where the “best” treatment is typically the one with the largest or smallest expected(long-run average) response. R&S procedures have been successfully extended to address situations that are encountered in stochastic simulation of alternative system designs, including unequal variances across alternatives, dependence both within the output of each system and across the outputs from alternative systems, and large numbers of alternatives to compare. In nearly all cases the estimator of the expected response is a (perhaps generalized) sample mean of the output of interest. In this article we derive R&S procedures that employ
control-variate estimators
instead of sample means. Control variates can be much more statistically efficient than sample means, leading to R&S procedures that are correspondingly more efficient. We also consider the related problem of estimating the expected value of the best (as opposed to the selected) system design.
Corrigendum
Authors: Ghosh Soumyadip , Henderson Shane G.
Published: May 2006

This note corrects an error in Ghosh and Henderson [2003].
The halfway vector disk for BRDF modeling
Authors: Edwards Dave , Boulos Solomon , Johnson Jared , Shirley Peter , Ashikhmin Michael , Stark Michael , Wyman Chris
Published: May 2006

We present a mathematical framework for enforcing energy conservation in a bidirectional reflectance distribution function (BRDF) by specifying halfway vector distributions in simple two-dimensional domains. Energy-conserving BRDFs can produce plausible rendered images with accurate reflectance behavior, especially near grazing angles. Using our framework, we create an empirical BRDF that allows easy specification of diffuse, specular, and retroreflective materials. We also present a second BRDF model that is useful for data fitting; although it does not preserve energy, it uses the same halfway vector domain as the first model. We show that this data-fitting BRDF can be used to match measured data extremely well using only a small set of parameters. We believe that this is an improvement over table-based lookups and factored versions of BRDF data.
Can't sing, can't act, can dance a little
Authors: Pattis Richard
Published: May 2006

The title of my talk comes from a Hollywood executive's comments on Fred Astaire's screen test. Much later, Katherine Hepburn remarking on Fred's eventual success with his most frequent partner said, "Fred gave Ginger [Rogers] class, and Ginger gave Fred sex [appeal]". I was surprised and delighted to win this award, and it started me thinking about how I got to where I am today. In my talk, I'll look back at 36 years of learning and teaching programming, and reflect on my many "dancing" partners. Some were around for a short time, some I dance with still, and some I dance with only in my dreams. In some cases, I led; in other cases I followed. Some dances were as graceful as a waltz, while others were more like an apache dance. During this talk I'll find some time to discuss "a view from the trenches" of four decades of teaching introductory programming, and if I can muster the courage, speculate on the future.
SNITCH
Authors: Niezgoda Sebastian , Way Thomas P.
Published: May 2006

Plagiarism of material from the Internet is a widespread and growing problem. Computer science students, and those in other science and engineering courses, can sometimes get away with a "cut and paste" approach to assembling a paper in part because the expected style of technical writing is less expositional than in liberal arts courses. Detection of cut and paste plagiarism is time-consuming when done by hand, and can be greatly aided by automated software tools. This paper reports on the design of a software tool called SNITCH that implements a fast and accurate plagiarism detection algorithm using the Google Web API. Issues related to plagiarism detection software are discussed and empirical results of a performance and accuracy study are presented.
The design of a history of computing course with a unique perspective
Authors: Cortina Thomas J. , McKenna Richard
Published: May 2006

In this paper, we describe the design and implementation of a new history of computing course that includes personal and historical perspectives from faculty members to supplement the course material. Despite decreasing enrollments in our computer science courses, this new course has achieved significantly large enrollments and a wide audience due to this unique faculty perspective in addition to the approval of this course as a general education requirement that addresses the implications of science and technology on society.
A CS0 course for the liberal arts
Authors: Cliburn Daniel C.
Published: May 2006

This paper describes a non-major introductory course in computer science, specifically for students at a liberal arts institution. College-wide writing and speaking requirements across the curriculum are supported through a variety of assignments. The computer science department has experienced many benefits as a result of offering this course, including improved performance by students in introduction to programming and greater enrollment numbers across departmental courses. Suggestions for improving future offerings of the class are also proposed in the paper.
The compiler course in today's curriculum
Authors: Waite William M.
Published: May 2006

The broadening of computer science education has called into question the roles of many traditional core courses. In order to remain viable, courses such as compiler construction must provide a coherent view of their subject matter that fits with the rest of the institution's curriculum. Three strategies have evolved for this course. As described in this paper, each strategy provides a model that a professor can use to design an appropriate course for their situation.
A Virtual Laboratory Model for Encouraging Undergraduate Research
Authors: Way Thomas P
Published: May 2006

Undergraduate students who perform research benefit greatly from the experience, yet achieving high levels of voluntary participation remains an elusive goal. This paper describes the implementation of an innovative laboratory model designed to encourage computer science undergraduates to actively pursue collaborative research with faculty and other students. As an extension of earlier research into team-based software engineering education, the Applied Computing Technology Laboratory was formed to provide an authentic and engaging experience in real-world computer science research. The model, which relies on a web site as its focus, is presented along with the results of one year of active research.
A model for summer undergraduate research experiences in emerging technologies
Authors: Knox Deborah L. , DePasquale Peter J. , Pulimood Sarah M.
Published: May 2006

Integrating emerging technologies into the curriculum is expected in our evolving discipline, although finding the time to master these can prove difficult. Institutional expectations for scholarly achievement need not take precedence; the use of an overarching theme for a summer research experience is presented as one approach to join a group of people with a unifying topic for study and discussion leading to the natural incorporation of the emergent technology into the curriculum.This paper presents a successful model for undergraduate summer research where participants, both faculty and students, investigated information security (IS) topics and learned from IS professionals. This was applied to individual research projects in disconnected areas in computing. The unifying experiences encouraged a collegial and supportive environment, firmly establishing peer and faculty / student collaboration. Student perceptions about the field and career options were positively effected, leading to increased interest in the emergent area as well as in future graduate studies.
How to integrate FPGAs into a computer organization course
Authors: Jipping Michael J. , Henry Sara , Ludewig Kathleen , Tableman Leslie
Published: May 2006

A crucial part of the Computer Organization course is the examination of and experimentation with digital logic circuits. In departments with limited budgets, however, this activity can be problematic. Due to historical roots and enrollment sizes, departments tend to focus on software aspects of computer science. This means that hardware concerns are often relegated to textbook and paper-and-pencil examination. This paper details how to use field programmable gate arrays -- hardware gates with a programming interconnection switch -- in the Computer Organization course. We will overview the reasons for using them, outline ways to use them effectively and cheaply, and demonstrate FEWD, our system for integrating visual design with FPGAs for student experimentation.
Exploiting on-line data sources as the basis of programming projects
Authors: DePasquale Peter
Published: May 2006

The Internet is an exciting place to find real, interesting, and interactive sources of data for use in the classroom. This data (often real world), can provide the basis of interesting projects for CS1 and CS2 courses. Additionally, the source or exchange protocol can be used as a gentle introduction for novice computer science majors to the myriad of data formats and emerging technologies available today. Presented here are a number of interesting data sources used during the 2004-2005 academic year in our own CS2 data structures course.
Teaching operating systems
Authors: Polze Andreas , Probert Dave
Published: May 2006

An operating system (OS) is a program that manages computer hardware. And although today's commercial-off-the-shelf desktop operating systems appear to be an integral part of PCs and workstation to many users, a fundamental understanding of the algorithms, principles, heuristics, and optimizations used is crucial for creating efficient application software. Furthermore, many of the principles in OS courses are relevant to large system applications like databases and web servers.Within this paper, we present our approach towards teaching OS concepts based on the Windows family of operating systems. In contrast to many stable Unix-based curricula, a Windows-based OS curriculum has to take into account the OS as a moving target. And although Windows source code has been made available to academic institutions, managing complexity is among the biggest challenges when teaching OS concepts based on Windows.Teaching experiences reported within this paper have lead to development of the "Curriculum Resource Kit (CRK)", an entire Windows-based OS curriculum that is freely available for download.
Discrete partnership
Authors: LeBlanc Mark D. , Leibowitz Rochelle
Published: May 2006

Discrete mathematics lies at the heart of the discipline of computing and represents one of the few bodies of knowledge with consistent content in our young and changing curriculum. We offer a model of a full-year, two-course experience of discrete structures with the initial course taught by computer science faculty and the second course taught by faculty in mathematics. We argue for the strengths gained in multiple and repeated exposure to the rich set of core topics and for the initial course to occur in the first year rather than the traditional advice to "take calculus". In particular, we present a model of collaboration with mathematics faculty that provides computer science students with an enriched breadth and depth of exposure while helping small departments to handle the constraints in scheduling.
An interactive tutorial system for Java
Authors: Roberts Eric
Published: May 2006

As part of the documentation for its library packages, the Java Task Force (JTF)developed an online tutorial system that enables teachers and students to explore the resources provided by the Task Force in a highly interactive style. The individual pages that make up the tutorial often include demonstration programs that the reader can experiment with while remaining on the same web page as the explanatory text. Although the original motivation for developing that tutorial system was to document the JTF packages themselves, the structure is general enough for teachers to design their own tutorials and interactive demonstrations. This paper describes the structure of that tutorial system and illustrates its use. In addition, the paper describes some work-in-progress that will make it possible to create interactive lecture demonstrations from PowerPoint™ slides.
Experiences using a collaborative electronic textbook
Authors: McFall Ryan , Dershem Herbert , Davis Darcy
Published: May 2006

Much has been made of the transition of the instructor's role from "Sage on the Stage" to "Guide on the Side", focusing on active and collaborative learning in the classroom. The process of acquiring knowledge from textbooks has largely remained unaffected by this transition. Our work on electronic textbooks (e-textbooks) has focused on building e-textbooks that extend the reach of collaborative and active learning techniques to the reading process. This paper describes the outcomes of using our e-textbook in a one semester course on programming language design and implementation, including the impact on student learning, the degree to which they took advantage of the e-textbook's collaborative and active features, and their reaction to the use of the e-textbook as the primary text resource.
OOP and the Janus principle
Authors: Adams Joel C.
Published: May 2006

It is easy for computer science students and educators to write software applications in Java or C++ that are not object-oriented. In this paper, we present the
Janus Principle
-- a simple software engineering principle (related to the MVC design pattern) whose use produces highly object-oriented code. We demonstrate its effect by developing a simple Java networking application, first without using the Janus Principle, and then using it. Students and educators who follow this principle will write programs containing highly reusable code.
Roles of variables and programming skills improvement
Authors: Byckling Pauli , Sajaniemi Jorma
Published: May 2006

Roles of variables capture tacit expert knowledge in a form that can be taught in introductory programming courses. A role describes some stereotypic use of variables, and only ten roles are needed to cover 99% of all variables in novice-level programs. This paper presents the results from a protocol analysis of a program creation task in an experiment where roles were introduced to novices learning Pascal programming. Students were divided into three groups that were instructed differently: in the traditional way with no treatment of roles in lectures or program animation; using roles in lectures but not in animation; and using a role-based program animator in addition to using roles in lectures. The results suggest that the introduction of roles provides novices a new conceptual framework for better mental processing of program information and that the use of role-based program animation increases novices' ability to apply data-related programming plans in program construction.
Computing Curricula 2005: The Overview Report
Authors: Shackelford Russell , McGettrick Andrew , Sloan Robert , Topi Heikki , Davies Gordon , Kamali Reza , Cross James , Impagliazzo John , LeBlanc Richard , Lunt Barry
Published: May 2006

In 2001, the ACM and the IEEE-CS published
Computing Curricula 2001
which contains curriculum recommendations for undergraduate programs in computer science. That report also called for additional discipline-specific volumes for each of computer engineering, information systems, and software engineering. In addition, it called for an
Overview Volume
to provide a synthesis of the various volumes. The Computing Curricula 2004 Task Force undertook the job of fulfilling the latter charge. The purpose of this session is to present the recently completed work of that Task Force, now known as
Computing Curricula 2005
(CC2005), and to generate discussion among, and feedback from SIGCSE members about ongoing and future work.
Things are clicking in computer science courses
Authors: Pargas Roy P. , Shah Dhaval M.
Published: May 2006

This paper presents and discusses a
modified approach
to teaching an algorithms and data structures course (CS4). The approach relies on frequent evaluation of student understanding of course content and enables the instructor to experiment with various exercises to facilitate peer-instruction and cooperative learning. It uses a web application called
MessageGrid
which enables instructor and students, each of whom has a laptop computer with wireless access to the web, to interact in a variety of ways both in and out of class.
Incorporating an intelligent tutoring system into CS1
Authors: Soh Leen-Kiat
Published: May 2006

Intelligent tutoring systems (ITSs) have been used to complement classroom instruction in recent years, and have been shown to facilitate learning. We incorporate an ITS named Intelligent Learning Materials Delivery Agent (ILMDA) into our CS1 course and collect evidence to validate two hypotheses: (1) The ITS improves student learning, (2) The ITS "learns" to tutor the students more efficiently and/or effectively. Our method of inquiry includes collecting data tracked while a student interacts with the ITS, post-test scores, and exam scores. We also use control and treatment groups, as well as different versions of the ILMDA in our experiments. Based on the results, we see indications that support the above two hypotheses.
Games as a "flavor" of CS1
Authors: Bayliss Jessica D. , Strout Sean
Published: May 2006

Introductory programming courses have a specific set of expected outcomes. One of the most often heard complaints in such courses is that they are divorced from the reality of application. Unfortunately, it is difficult to find areas for application that all students have the background knowledge for and that are engaging and challenging. One such area is computer games and we have developed a cohesive CS1 course that provides traditional outcomes from within the context of games as an application area in both the lecture and lab components of the course. This course was piloted as a ten-week distance program for incoming computer science students with the defining features that the program carried no academic credit and offered no end grades. We discuss the overwhelming interest in this course as well as objective and suobjective student experiences. One of the most important outcomes of the summer course was that it brought students with similar interests and goals together. We discuss this and the different ways we have found to discuss computer science course topics from within a games context.
An ethics and security course for students in computer science and information technology
Authors: Epstein Richard G.
Published: May 2006

This paper describes an undergraduate course in computer security that has a strong ethical component. Ethical and related security topics are interwoven. The emphasis is on the kind of research that computer scientists and information technologists are conducting in order to address the fundamental problems in computer security. There is also a great emphasis on encouraging student creativity.
TextMOLE
Authors: Waegel Daniel B. , Kontostathis April
Published: May 2006

The paper describes the first version of the TextMOLE (Text Mining Operations Library and Environment) system for textual data mining. Currently TextMOLE acts as an advanced indexing and search engine: it parses a data set, extracts relevant terms, and allows the user to run queries against the data. The system design is open-ended, robust, and flexible. The tool is designed to quickly analyze a corpus of documents and determine which parameters will provide maximal retrieval performance. Thus an instructor can use the tool to demonstrate information retrieval concepts in the classroom, or use the tool to encourage hands-on exploration of concepts often covered in an introductory course in information retrieval or artificial intelligence. Reseachers will find the tool useful when a `quick and dirty' analysis of an unfamiliar collection is required.
Effective techniques for the generalized low-power binding problem
Authors: Davoodi Azadeh , Srivastava Ankur
Published: May 2006

This article proposes two very fast graph theoretic heuristics for the low power binding problem given fixed number of resources and multiple architectures for the resources. First, the generalized low power binding problem is formulated as an Integer Linear Programming (ILP) problem that happens to be an NP-complete task to solve. Then two polynomial-time heuristics are proposed that provide a speedup of up to 13.7 with an extremely low penalty for power when compared to the optimal ILP solution for our selected benchmarks.
Foundations and applications for secure triggers
Authors: Futoransky Ariel , Kargieman Emiliano , Sarraute Carlos , Waissbein Ariel
Published: May 2006

Imagine there is certain content we want to maintain private until some particular event occurs, when we want to have it automatically disclosed. Suppose, furthermore, that we want this done in a (possibly) malicious host. Say the confidential content is a piece of code belonging to a computer program that should remain ciphered and then “be triggered” (i.e., deciphered and executed) when the underlying system satisfies a preselected condition, which must remain secret after code inspection. In this work we present different solutions for problems of this sort, using different “declassification” criteria, based on a primitive we call
secure triggers
. We establish the notion of secure triggers in the universally composable security framework of Canetti [2001] and introduce several examples. Our examples demonstrate that a new sort of obfuscation is possible. Finally, we motivate its use with applications in realistic scenarios.
Using Pin as a memory reference generator for multiprocessor simulation
Authors: McCurdy Collin , Fischer Charles
Published: May 2006

In this paper we describe how we have used Pin to generate a multithreaded reference stream for simulation of a multiprocessor on a uniprocessor. We have taken special care to model as accurately as possible the effects of cache coherence protocol state, and lock and barrier synchronization on the performance of multithreaded applications running on multiprocessor hardware.We first describe a simplified version of the algorithm, which uses semaphores to synchronize instrumented application threads and the simulator. We then describe modifications to that algorithm to model the microarchitectural features of the Itanium2 that affect the timing of memory reference issue. An experimental evaluation determines that, while our methods enable accurate simulation, the use of semaphores has negative impact on the performance of the simulator.
Controlling program execution through binary instrumentation
Authors: Pan Heidi , Asanović Krste , Cohn Robert , Luk Chi-Keung
Published: May 2006

Binary instrumentation has been widely used to observe dynamic program behavior, but current binary instrumentation systems do not allow the tool writer to alter the program execution path. This paper introduces some simple and general mechanisms for a binary instrumentation infrastructure to provide control over the application's execution path, allowing tools to replay or skip parts of the application, and to start or switch between threads. Specifically, the technique provides the following three functionalities for both single-threaded and multi-threaded applications: (1) checkpointing the execution state, (2) resuming execution at a checkpoint, and (3) starting execution at an arbitrary point in the program with a specified architectural state. We describe our implementation of these functionalities in Pin, a dynamic binary instrumentation infrastructure from Intel [5]. We demonstrate the usefulness of our mechanism by describing several binary instrumentation tools that have been built using this interface, including a transactional memory model and a thread scheduler.
Review of “Grid Database Design by April Wells,” Auerbach Publications, 2005, $79.95, ISBN: 0849328004.
Authors: Paramithiotti Andrea
Published: May 2006

Review of “Grid Database Design by April Wells,” Auerbach Publications, 2005, $79.95, ISBN: 0849328004.
Dietary fiber decreases colonic epithelial cell proliferation and protein synthetic rates in human subjects
Authors: Weerasooriya Viraine , Rennie Michael J. , Anant Shri , Alpers David H. , Patterson Bruce W. , Klein Samuel
Published: May 2006

Although it has been proposed that high fiber consumption can prevent proliferative diseases of the colon, the clinical data to support this hypothesis have been inconsistent. To provide a more robust measure of the effects of fiber on colonic mucosal growth than previous studies, we evaluated both cell proliferation and colonic mucosal protein synthesis in nine healthy volunteers after they consumed a typical Western diet (<20 g fiber/day) or a Western diet supplemented with wheat bran (24 g/day) in a randomized crossover design. Biopsies taken from the sigmoid colon were used to assess mucosal proliferation by determining proliferating cell nuclear antigen (PCNA) in crypt cells and to assess mucosal protein synthetic rate using stable isotopically labeled leucine infusion. Fiber supplementation produced a 12% decrease in labeling index (%crypt cells stained with PCNA) ( P < 0.001) and an 11% decrease in mucosal protein fractional synthetic rate (FSR; P < 0.05). Moreover, mucosal protein FSR correlated directly with labeling index (r2= 0.22, P < 0.05). These data demonstrate that increased wheat bran consumption decreases colonic mucosal proliferation and support the potential importance of dietary fiber in preventing proliferative diseases of the colon.
Miniature Codices from Kellis
Authors: Hope Colin ,   Worp
Published: May 2006

This article contains a first edition of two wooden mini-codices found during Australian excavations at Ismant el-Kharab (ancient Kellis) in the Dakhleh Oasis (Egypt). The first codex contains fifteen Greek hexameters belonging to an anonymous and unknown parody of Homer; the second codex contains three Greek division tables. Both texts date from the fourth century CE and apparently come from a local school.
Matriliny, Islam and Gender in Northern Mozambique
Authors: Bonate Liazzat
Published: May 2006

Using gender as the major line of difference, the paper examines the diversity within Islam in northern Mozambique, in which, despite strong historical ties to the Swahili world and waves of Islamic expansion, as well as attempts to establish and police an Islamic 'orthodoxy', matriliny continues to be one of the main cultural features. Concentrating on two coastal regions, Mozambique Island and Angoche, and on three urban zones of the modern provincial capital, Nampula City, the paper addresses the reasons for the endurance of matriliny, through historical processes that brought about different currents of Islam, and discusses the ways in which the colonial and post-colonial state, while attempting to control the often conflicting Islamic and African 'traditional' authorities, have contributed to the perpetuation of this conflict as well as to the endurance of matriliny.
Tropical Wave Driving of the Annual Cycle in Tropical Tropopause Temperatures. Part II: Model Results
Authors: Norton W. A.
Published: May 2006

The atmospheric response to a localized distribution of tropical heating is examined in terms of the stationary waves excited and how these impact the mean flow near the tropical tropopause. This is done by examining nonlinear simulations of the Gill model with a primitive equation model that extends from the surface up into the stratosphere. The model produces strong cooling of zonal mean temperatures near the tropical tropopause when the heating is on the equator but weaker cooling with the heating at 15°N. The model shows that equatorial Rossby waves that penetrate the lower stratosphere and changes in EP flux divergence that correspond to the observed changes between December and August. It is suggested that ascent in the upper tropical troposphere is driven by vorticity advection or equivalently potential vorticity fluxes due to these equatorial Rossby waves, particularly when the heating is close to the equator. The model results provide support to the hypothesis that the annual cycle in tropical tropopause temperatures is a result of the annual variation in latitude of tropical heating and that equatorial Rossby waves are key in producing the response in the upper troposphere and lower stratosphere.
The Structure of Thermals in Cumulus from Airborne Dual-Doppler Radar Observations
Authors: Damiani Rick , Vali Gabor , Haimov Samuel
Published: May 2006

A newly developed technique for airborne dual-Doppler observations with the Wyoming Cloud Radar is used to characterize the velocity fields in vertical planes across cumulus turrets. The clouds sampled were continental in nature, with high bases (near 0°C) and with depths of 2–3 km. Clear evidence was found that the clouds evolved through sequences of bubbles, or thermals, with well-defined toroidal circulations, or vortex rings. The ring core and tube diameters were about 200–600 m, leading to turret sizes of 1–2 km in the horizontal. The largest updraft speeds were observed in the ring centers, but regions of turbulent, ascending air extended behind the thermals to distances comparable with the toroid sizes. Vertical shear of ambient winds, when present, led to a tilting of the updrafts and toroids. Patterns in the reflectivity and velocity fields indicated regions of major intrusions into the thermals, accompanied by entrainment of ambient air, or recycling of larger hydrometeors, depending on their location. In addition, at the upper cloud/environment interface, instability nodes contributed to further entrapment of cloud-free air. The observations presented in this paper constitute clear demonstrations and quantitative characterization of vortical circulations in growing cumulus turrets; they should provide a more reliable basis for the assessment of simulations and of model parameterizations.
Above, Beside, Within: The Anglican Theology of Austin Farrer
Authors: MacSwain Robert
Published: May 2006

Austin Farrer is highly praised but curiously under-read. Despite being recognized as ‘possibly the greatest Anglican mind of the 20th century,’ his influence in discussions of Anglican identity and theology is almost non-existent. As an attempt to remedy this deficit, this paper provides a sketch of Farrer's life and work, and then presents him as a specifically Anglican theologian through considering a sermon, a meditation on the Apostles' Creed, and a set of lectures to Oxford undergraduates. But presenting Farrer as ‘a specifically Anglican theologian’ is problematic if we cannot agree on the nature of Anglican theology. Therefore, the paper concludes by referencing a debate between Stephen Sykes and Paul Avis on this question, and asks if Farrer can function as a paradigm for contemporary Anglican theologians.
Facile Cleavage of Aryl Haloacetates and 2-Chloroethyl Carboxylic Esters with Sodium Telluride. A One-pot Conversion of Aryl Esters into Aryl Ethers under Aprotic Conditions
Authors: Suzuki Hitomi , Padmanabhan Seetharamaiyer , Ogawa Takuji
Published: May 2006

Sodium telluride, prepared under aprotic conditions, cleaved aryl haloacetates and 2-chloroethyl carboxylates at room temperature to give phenolic compounds and carboxylic acids, respectively. Based on this cleavage a one-pot conversion of aryl esters into aryl ethers was achieved.
Synthesis of Salviolone, a Cytotoxic Benzotropolonoid Bisnorditerpene from Salvia miltiorrhiza
Authors: Mori Masahito , Inouye Yoshinobu , Kakisawa Hiroshi
Published: May 2006

The structure of salviolone was unequivocally confirmed by synthesis in six steps starting from 3,3-dimethyl-2-vinylcyclohexene and methyl acetylenedicarboxylate.
Asymmetric Bioreduction of Ethyl 3-Oxobutanoate by Immobilized Baker’s Yeast Entrapped in Calcium Alginate Beads. Application of the Immobilized Biocatalyst to the Synthesis of (5Z,13S)-5-Tetradecen-13-olide, Aggregation Pheromone of Cryptolestes Grain Beetle
Authors: Naoshima Yoshinobu , Nakamura Akihiro , Nishiyama Tadashi , Haramaki Toshikatsu , Mende Mitsuo , Munakata Yoshihito
Published: May 2006

Immobilized baker’s yeast entrapped in calcium alginate beads of 1–1.5 mm diameter was reusable more than 10 times and stereoselectively reduced ethyl 3-oxobutanoate to the corresponding (S)-hydroxy ester in high chemical and optical yields. The immobilized biocatalyst was also successfully used for an asymmetric synthesis of (5Z,13S)-5-tetradecen-13-olide, a synergist of the aggregation pheromone of the flat grain beetle.
A Regio- and Stereocontrolled Synthesis of (+)-Isocarbacyclin via (1S,2R,5R)-Bicyclo[3.3.0]oct-6-en-endo-2-ol
Authors: Hashimoto Shun-ichi , Kase Satoshi , Shinoda Tomohiro , Ikegami Shiro
Published: May 2006

An expeditious synthesis of (+)-isocarbacyclin based on a facile access to (1S,2R,5R)-bicyclo[3.3.0]oct-6-en-endo-2-ol has been accomplished, incorporating controlled ene-reaction and elaboration of ω appendage via Julia coupling as key steps.
Dependence of the Mixed-Valence States on Crystal Form in 1′,1″′-Ditetradecylbiferrocenium Triiodide
Authors: Nakashima Satoru , Sano Hirotoshi
Published: May 2006

Remarkable dependence of the mixed-valence states on crystal form was observed in 1′,1″′-ditetradecylbiferrocenium triiodide. One crystal form showed a temperature-independent trapped-valence state, while the other was found to be a temperature-dependent valence state in which a trapped-valence state at lower temperatures and an averaged-valence state at higher temperatures are observed.
On the Flory–Stockmayer Model of Gelation Accompanied by the Intra Particle Crosslinking Reaction
Authors: Fukutomi Takashi
Published: May 2006

The approximative particle size distribution function in the crosslinking reaction according to the Flory–Stockmayer model involving intra particle crosslinking is derived by the modification of the general solution obtained by Leyvraz and Tschudi.
Direct Separation of Enantiomers by Reversed-phase High Performance Liquid Chromatography on Cellulose Tris(3,5-dimethylphenylcarbamate)
Authors: Ikeda Kuniki , Hamasaki Toshio , Kohno Hisashi , Ogawa Takayuki , Matsumoto Takashi , Sakai Jun-ichi
Published: May 2006

Various types of enantiomeric drugs were optically separated by reversed-phase high performance liquid chromatography using cellulose tris(3,5-dimethylphenylcarbamate) as a chiral stationary phase.
Novel Ring Transformation of 3-Benzoylisoxazolidines into 2-Hydroxydihydrofurans. N–O Cleavage vs. 1,3-Dipolar Cycloreversion
Authors: Tanaka Kiyoshi , Mori Takami , Mitsuhashi Keiryo
Published: May 2006

Thermal ring transformation of 3-benzoylisoxazolidines gives 2-hydroxydihydrofurans together with α-benzoylenamines, the product ratio of both compounds depending on the 4- and 5-substituents of the isoxazolidine ring. The ring transformation is in contrast to the case of analogous 3-phenylisoxazolidines, resulting in 1,3-dipolar cycloreversion.
Preparation and Structure of the 18-Crown-6 · 2(Chloral Hydrate) Complex
Authors: Chênevert Robert , Chamberland Daniel
Published: May 2006

18-Crown-6 forms a stable 1:2 host–guest complex with chloral hydrate. This complex is not dissociated in non-polar solvents.
Electrochemical Coating of Phthalocyanines on an Al Substrate Using Aqueous Surfactant Solutions
Authors: Hoshino Katsuyoshi , Yokoyama Seiichiro , Saji Tetsuo , Kokado Hiroshi
Published: May 2006

Thin films of copper phthalocyanine and metal-free phthalocyanine were electrochemically prepared on an Al substrate from their aqueous surfactant solutions. Surface coverage of these pigments was investigated as a function of the amount of electricity. Characterization of the films were performed with SEM, IR, and visible absorption spectroscopies.
Reduction of Carboxylic Acid with 2-Propanol over Hydrous Zirconium Oxide
Authors: Takahashi Kyoko , Shibagaki Makoto , Kuno Hideyuki , Matsushita Hajime
Published: May 2006

The vapor-phase reduction of carboxylic acids with 2-propanol was found to proceed efficiently over hydrous zirconium(IV) oxide, and the corresponding alcohols were obtained in high yield. Esters were also reduced.
Crystal Structures and Electrical Properties of BEDT-TTF Salts of Mercury(II) Thiocyanate with and without K Ion
Authors: Oshima Masashi , Mori Hatsumi , Saito Gunzi , Oshima Kokichi
Published: May 2006

The electrochemical oxidation of BEDT-TTF with Hg(SCN)2, KSCN, and 18-crown-6 ether yielded two different BEDT-TTF salts of mercury(II) thiocyanate depending on the solvent used. The K+ containing salt, (BEDT-TTF)2[KHg(SCN)4], was metallic down to 1.5 K with various temperature dependences. The crystal structures showed an alternating stacking of two-dimensional networks of BEDT-TTF molecules and of KHg(SCN)4 anions. The other modification (BEDT-TTF)3[Hg(SCN)3] exhibited metal-insulator (MI) transition at around 180 K.
First Isolation of a π-Perfluoroallylic Complex from a Transition Metal Hydride with Hexafluorobuta-1,3-diene
Authors: Sasaoka Shin-ichi , Joh Takashi , Tahara Tadasu , Takahashi Shigetoshi
Published: May 2006

Dicarbonyl(η3-1,1,2,3,4,4-hexafluoro-2-butenyl)(triphenyl-phosphine)cobalt(I) was isolated at the first time from the reaction of tetracarbonylhydridocobalt(I) with hexafluorobuta-1,3-diene and triphenylphosphine.
Stereoselectivity in Electron-Transfer Reactions of Tris(ethylenediamine)cobalt(II) with Several Anionic Cobalt(III) Complexes
Authors: Tatehata Akira , Mitani Tsuyoshi
Published: May 2006

The stereoselectivities in the electron-transfer reactions of [Co(en)3]2+ with eight Δ anionic Co(III) complexes in aqueous solution have been determined by observing the enantiomeric excesses of the [Co(en)3]3+ product. The results are compared with the ion-pairing stereoselectivity between [Co(en)3]3+ and the anionic complexes. Even the Δ anionic complexes which form favorable pairs with Δ-[Co(en)3]3+ yielded the excesses of Λ-[Co(en)3]3+ product.
[1,2-Benzenediolato(2−)-O,O′]oxotitanium. A Mild and Efficient Catalyst for the Michael Reaction of Ketene Silyl Acetals with α,β-Unsaturated Ketones
Authors: Mukaiyama Teruaki , Hara Ryuichiro
Published: May 2006

In the presence of a catalytic amount of [1,2-benzenediolato(2−)-O,O′]oxotitanium, ketene silyl acetals smoothly react with α,β-unsaturated ketones to afford the corresponding Michael adducts in high yields.
Evolution of Ferromagnetism in the Triarylmethane Resin Synthesized under a Magnetic Field
Authors: Ota Michiya , Otani Sugio
Published: May 2006

A thermosetting resin composed of triarylmethane structure was prepared under a magnetic field. The resulting resin exhibited ferromagnetic properties with excellent reproducibility.
Evolution of Ferromagnetic Properties by Dehydrogenation of Triarylmethane Resin
Authors: Ota Michiya , Otani Sugio , Igarashi Michiya
Published: May 2006

Organic ferromagnets have been successfully prepared by dehydrogenation from the triarylmethane resins and the irradiation with ultraviolet or laser light in the presence of photo-oxidizing agent is found to be effective to the dehydrogenation.
Kinetic Resolution of α-Arylcarboxylic Acid Derivatives by a Catalytic Use of a Chiral Titanium Alkoxide
Authors: Narasaka Koichi , Kanai Fumihiko , Okudo Makoto , Miyoshi Norikazu
Published: May 2006

Kinetic resolution of racemic α-arylcarboxylic acids is successfully achieved by a catalytic use of titanium tetraisopropoxide and a chiral 1,4-diol in the reaction of the corresponding 2-pyridinethiol esters and isopropyl alcohol.
Conversion of Formamides to Alcohols via N-Nitrosation
Authors: Iwata Masaaki , Kuzuhara Hiroyoshi
Published: May 2006

Secondary formamides were found to be favorable sources for the efficient oxygenation site via N-nitrosation. Thermal reaction (85 °C in benzene) of N-nitroso formamides proceeded effectively to provide the corresponding formates in good yields, which, then, were hydrolyzed to alcohols under weakly basic conditions. In treatment of optically active formamide, the corresponding alcohol was isolated with 72% retention of configuration.
Stereoselective Synthesis of Ethyl (2E,4E)-Alkadienoates from Ethyl Sulfolane-2-carboxylate
Authors: Saigo Kazuhiko , Kudo Kazuaki , Hashimoto Yukihiko , Kihara Nobuhiro , Hasegawa Masaki
Published: May 2006

α,β,γ,δ-Unsaturated esters were conveniently synthesized from ethyl sulfolane-2-carboxylate through alkylation and oxidation followed by the retro Diels–Alder reaction of the resulting 3-sulfolene derivatives. The reaction proceeded with high E,E-selectivity.
Cyclic Voltammetry of Cobaloxime-immobilized Powdery Poly(4-vinylpyridine)
Authors: Kijima Masashi , Kato Masahiro , Sato Takeo
Published: May 2006

A new method for investigating the redox behavior of powdery polymer carrying cobaloxime is described. Benzylcobaloxime and chlorocobaloxime are each immobilized into cross-linked poly(4-vinylpyridine). Insoluble polymers soaked in an electrolyte solution are set on a platinum working electrode. The redox behaviors of these cobaloximes were recorded in a solid state by cyclic voltammetry.
Selective Electrocatalytic Reduction of Carbon Dioxide to Methanol on Ru-modified Electrode
Authors: Arai Gorou , Harashina Tomitaka , Yasumori Iwao
Published: May 2006

CO2 was electrochemically reduced to CH3OH in aqueous Na2SO4 solution on a Ru-modified glassy carbon electrode. Ru was fixed on poly(hydroquinone/p-benzoquinone) prepared by electropolymerization of mercaptohydroquinone. The reduction of CO2 proceeded with markedly low overvoltage, starting at −0.5 V vs. SCE at room temperature. The current efficiency for CH3OH formation attained ca. 100% at −0.7 V vs. SCE with a current density of ca. 0.2 mA/cm2.
A New Replica Method for Electron Microscopic Observation of Langmuir–Blodgett Film with Plasma Polymerized Film by Glow Discharge
Authors: Tanaka Akira , Yamaguchi Masashi , Iwasaki Takashi , Iriyama Keiji
Published: May 2006

A new replica method for transmission electron microscopy with plasma polymerized film by glow discharge was originally developed. The method was found to be applicable for the surface observation of Langmuir–Blodgett film.
Ab Initio Calculations on Keto/Enol Tautomers of Pterins. On the Significance of the Enol Tautomer of Pterin Ring in the Enzymatic Reduction of Dihydrofolate by DHFR
Authors: Uchimaru Tadafumi , Tsuzuki Seiji , Tanabe Kazutoshi , Furukawa Kensuke , Taira Kazunari
Published: May 2006

Ab initio and semi-empirical calculations were carried out on keto/enol tautomers of 6-methyl-7,8-dihydropterin, a model compound for the natural substrate of dihydrofolate reductase. The most likely conformer of pterin ring (inner enol 3) during the hydride transfer from NADPH was computationally chracterized.
A New Synthesis of Porphyrins via Tetramerization of 2-(Hydroxymethyl)pyrroles
Authors: Ono Noboru , Maruyama Kazuhiro
Published: May 2006

Acid catalyzed cyclization of 2-(hydroxymethyl)pyrroles with electron-donating substituents at the β-position gives a mixture of four isomers of porphyrins (type I-IV) in the homogeneous reaction. The isomerization during cyclization can be minimized in the heterogeneous reaction using silica gel as an acid catalyst to give type I porphyrins selectively.
A Facile Conversion of α-Nitroepoxides into 1,2-Diones and α-Iodoketones
Authors: Vankar Yashwant D , Saksena Rajendra K , Bawa Anita
Published: May 2006

1,2-Diones and α-iodoketones have been prepared from α-nitroepoxides by treatment with DMSO/BF3·Et2O followed by Et3N and BF3·Et2O/NaI respectively.
Azilidine–Trimethylsilyl Bromide–Ph4SbBr System as a Novel Selective Reagent for Synthesis of Silyl Enol Ethers from Cyclic Ketones
Authors: Fujiwara Masahiro , Baba Akio , Matsuda Haruo
Published: May 2006

Azilidine–trimethylsilyl bromide–tetraphenylstibonium bromide system is an effective reagent to produce silyl enol ethers from cyclic ketones. This had the specific selectivity to silylate cyclic ketones exclusively even in the case of coexsisting with acyclic ketones.
Ferromagnetic Interaction of Imidazolate-Bridged Copper(II)–Chromium(III)–Copper(II) Complex
Authors: Matsumoto Naohide , Inoue Keiji , Okawa Hisashi , Kida Sigeo
Published: May 2006

Imidazolate-bridged copper(II)–chromium(III)–copper(II) complex, [Cu(A)Cr(salen)Cu(A)]ClO4·3H2O, has been synthesized and characterized, where H2A = 4-(6-methyl-8-oxo-2,5-diazanona-1,5,7-trienyl)imidazole and H2salen = N,N′-di(salicylidene)ethylenediamine, respectively. The magnetic moment per molecule increases from 4.61 BM at 297.8 K to the maximum value 5.27 BM at 14 K, and then decreases to 4.42 BM at 4.4 K. The magnetic behavior shows that there operates a ferromagnetic interaction between chromium(III) and copper(II) ions through imidazolate group.
Catalytic Hydroxylation of Aromatic Compounds with O2 by a Catecholatoiron Complex in Acetonitrile Using Hydroquinones as Reductants
Authors: Funabiki Takuzo , Tsujimoto Motoyoshi , Ozawa Satoshi , Yoshida Satohiro
Published: May 2006

Hydroquinones have been found to be useful as reductants for one-step hydroxylation of aromatic compounds by nonheme iron complex with activation of O2 in anhydrous organic solvents. The iron complex is easily prepared by mixing FeCl3, pyrocatechol, and pyridine. The efficiency of hydroquinones as reductants is greatly dependent on the substituent: t-Bu- > 2,5-t-Bu2- >> H-hydroquinone.
Efficient Activation of Acetals toward Nucleophiles with [Rh(COD)Cl]2Catalyst. New Method for the Preparation of Aldols from Acetals and Silyl Enol Ethers by the Combined Use of Catalytic Amounts of [Rh(COD)Cl]2 and Trimethylsilyl Cyanide
Authors: Mukaiyama Teruaki , Soga Tsunehiko , Takenoshita Haruhiro
Published: May 2006

In the presence of a catalytic amount of [Rh(COD)Cl]2, di-μ-chloro-bis(1,5-cyclooctadiene)dirhodium, trimethylsilyl cyanide smoothly reacts with acetals derived from aliphatic, unsaturated and aromatic aldehydes to form the corresponding α-cyano derivatives in high yields. In the coexistence of catalytic amounts of [Rh(COD)Cl]2 and trimethylsilyl cyanide, silyl enol ethers also react with acetals to yield the corresponding aldol adducts under almost neutral conditions.
Preparation and Characterization of “PbVS3” a New Composite Layered Compound
Authors: Gotoh Yoshito , Onoda Mitsuko , Goto Midori , Oosawa Yoshinao
Published: May 2006

“PbVS3”, a new ternary layered compound, has been obtained. The structure is composed of two kinds of layers of pseudo-tetragonal PbS and pseudo-orthohexagonal VS2. They are alternately stacked together forming composite crystal of LaCrS3 type. All of the powder X-ray diffraction peaks are well indexed on the basis of only a monoclinic PbS subcell.
Diastereoselective Synthesis of γ-Lactones by the Aldol-Type Reaction of Ethyl 2,2-Dialkoxycyclopropanecarboxylates with Aldehydes
Authors: Saigo Kazuhiko , Shimada Shigeru , Hashimoto Yukihiko , Hasegawa Masaki
Published: May 2006

Ethyl 2,2-dialkoxycyclopropanecarboxylates, considered as three carbon 1,3-dipole equivalents, reacted smoothly with aldehydes in the presence of titanium(IV) bromide to give γ-lactones in good yields with high diastereoselectivity.
Liquid Crystalline Properties of 4-Octyloxybiphen-4′-yl 4-Hydroxybenzoate and 4-Hydroxyphenyl 4-Octyloxybiphenyl-4′-carboxylate
Authors: Takeda Hitoshi , Sakurai Yoshiaki , Takenaka Shunsuke , Miyake Hajime , Doi Takashi , Kusabayashi Shigekazu
Published: May 2006

4-Octyloxybiphen-4′-yl 4-hydroxybenzoate and 4-hydroxyphenyl 4-octyloxybiphenyl-4′-carboxylate show a nematic phase, and the former compound also shows abnormally stable smectic A phase, where an associated hydrogen bond complex is assumed to be the origin.