bluuebunny/crossref_metadata_2025 huggingface dataset:
High performance SQL through low-level system integration
Authors: Borr A.
Published: November 2005

NonStop SQL [TM] achieves high performance through an implementation which integrates SQL record access with the pre-existing disk I/O and transaction management subsystems, and moves SQL function downward from the client to the server level of these subsystems. System integration and movement of function to the server reduce message traffic and CPU consumption by putting SQL optimizations at the lower levels of the system. Examples of such optimizations are message traffic savings by filtering data and applying updates at the data source, I/O savings by SQL-optimized buffer pool management, and locking and transaction journaling techniques which take advantage of SQL semantics. Achieving message traffic reduction is particularly important in a distributed, non shared-memory architecture such as the Tandem NonStop System. The result of this implementation is an SQL system which matches the performance of the pre-existing DBMS, while inheriting such pre-existing architecturally-derived features as high availability, transaction-based data integrity, and distribution of both data and execution.
Semantic lock models in object-oriented distributed systems and deadlock resolution
Authors: Roesler M. , Burkhard W. A.
Published: November 2005

We propose a distributed algorithm for detection and resolution of resource deadlocks in object-oriented distributed systems. The algorithm proposed is shown to detect and resolve all O(n
1
) cycles present in the worst case waits-for-graph (WFG) with n vertices by transmitting O(n
3
) messages of small constant size. Its average time complexity has been shown to be O(ne), where e is the number of edges in the WFG After deadlock resolution, the algorithm leaves information in the system concerning dependence relations of running transactions. This information will preclude the wasteful retransmission of messages and reduce the delay in detecting future deadlocks

.
Formal model of correctness without serializabilty
Authors: Korth H. K. , Speegle G.
Published: November 2005

In the classical approach to transaction processing, a concurrent execution is considered to be correct if it is equivalent to a non-concurrent schedule. This notion of correctness is called
serializability
. Serializability has proven to be a highly useful concept for transaction systems for data-processing style applications. Recent interest in applying database concepts to applications in computer-aided design, office information systems, etc. has resulted in transactions of relatively long duration. For such transactions, there are serious consequences to requiring serializability as the notion of correctness. Specifically, such systems either impose long-duration waits or require the abortion of long transactions. In this paper, we define a transaction model that allows for several alternative notions of correctness without the requirement of serializability. After introducing the model, we investigate classes of schedules for transactions. We show that these classes are richer than analogous classes under the classical model. Finally, we show the potential practicality of our model by describing protocols that permit a transaction manager to allow correct non-serializable executions
A data/knowledge base management testbed and experimental results on data/knowledge base query and update processing
Authors: Ramnarayan R. , Lu H.
Published: November 2005

This paper presents our experience in designing and implementing a data/knowledge base management testbed. The testbed consists of two layers, the knowledge manager and the database management system, with the former at the top. The testbed is based on the logic programming paradigm, wherein data, knowledge, and queries are all expressed as Horn clauses. The knowledge manager compiles pure, function-free Horn clause queries into embedded-SQL programs, which are executed by the database management system to produce the query results. The database management system is a commercial relational database system and provides storage for both rules and facts. First, the testbed architecture and major data structures and algorithms are described. Then, several preliminary tests conducted using the current version of the testbed and the conclusions from the test results are presented. The principal contributions of this work have been to unify various concepts, both previously published and new ones we developed, into a real system and to present several insights into data/knowledge base management system design gleaned from the test results and our design and implementation experience.
A self-controlling interpreter for the relational production language
Authors: Delcambre L. M.L. , Etheredge J. N.
Published: November 2005

The Relational Production Language (RPL) solves the paradigm mismatch between expert systems and database systems by relying on the relational data model as the underlying formalism for an expert system. The result is a formally-defined production system language with immediate access to conventional databases. Working memory is modeled as a relational database and rules consist of a relational query on the left hand side (LHS) and database updates on the right hand side (RHS). This paper reports on the design of the RPL 1 0 prototype. The prototype directly executes RPL programs and capitalizes on the inherent advantages of the relational approach, particularly for intra-rule and inter-rule parallelism. By using a self-describing approach for representing the interpreter data structures, the interpreter is a self-controlling system that allows conflict resolution, error handling and a wide spectrum of software metrics to be explicitly specified using RPL meta-rules.
A data model and query language for EXODUS
Authors: Carey Michael J. , DeWitt David J. , Vandenberg Scott L.
Published: November 2005

In this paper, we present the design of the EXTRA data model and the EXCESS query language for the EXODUS extensible database system. The EXTRA data model includes support for complex objects with shared subobjects, a novel mix of object- and value-oriented semantics for data, support for persistent objects of any type in the EXTRA type lattice, and user-defined abstract data types (ADTs). The EXCESS query language provides facilities for querying and updating complex object structures, and it can be extended through the addition of ADT functions and operators, procedures and functions for manipulating EXTRA schema types, and generic set functions EXTRA and EXCESS are intended to serve as a test vehicle for tools developed under the EXODUS extensible database system project.
Modeling class hierarchies with contradictions
Authors: Borgida A.
Published: November 2005

One characteristic feature of object-oriented systems and knowledge bases (semantic data models, conceptual modeling languages, Al frames) is that they offer as a basic paradigm the notion of objects grouped into classes, which are themselves organized in subclass hierarchies. Through ideas such as inheritance and bounded polymorphism, this feature supports the technique of “
abstraction by generalization
”, which has been argued to be of importance in designing Information Systems [11, 2].

We provide in this paper examples demonstrating that in some applications
over-generalization
is likely to occur an occasional natural subclass may contradict in some way one if its superclass definitions, and thus turn out not to be a strict subtype of this superclass. A similar problem arises when an object is allowed to be a member of several classes which make incompatible predictions about its type. We argue that none of the previous approaches suggested to deal with such situations is entirely satisfactory.

A language feature is therefore presented to permit class definitions which contradict aspects of other classes, such as superclasses, in an object-based language. In essence, the approach requires contradictions among class definitions to be
explicitly
acknowledged. We define a semantics of the resulting language, which restores the condition that subclasses are both subsets and subtypes, and deals correctly with the case when an object can belong to several classes. This is done by separating the notions of “class” and “type”, and it allows query compilers to detect type errors as well as eliminate some run-time checks in queries, even in the presence of “contradictory” class definitions.
Statistical grid-based clustering over data streams
Authors: Park Nam Hun , Lee Won Suk
Published: November 2005

A data stream is a massive unbounded sequence of data elements continuously generated at a rapid rate. Due to this reason, most algorithms for data streams sacrifice the correctness of their results for fast processing time. The processing time is greatly influenced by the amount of information that should be maintained. This paper proposes a statistical grid-based approach to clustering data elements of a data stream. Initially, the multidimensional data space of a data stream is partitioned into a set of mutually exclusive equal-size initial cells. When the support of a cell becomes high enough, the cell is dynamically divided into two mutually exclusive intermediate cells based on its distribution statistics. Three different ways of partitioning a dense cell are introduced. Eventually, a dense region of each initial cell is recursively partitioned until it becomes the smallest cell called a unit cell. A cluster of a data stream is a group of adjacent dense unit cells. In order to minimize the number of cells, a sparse intermediate or unit cell is pruned if its support becomes much less than a minimum support. Furthermore, in order to confine the usage of memory space, the size of a unit cell is dynamically minimized such that the result of clustering becomes as accurate as possible. The proposed algorithm is analyzed by a series of experiments to identify its various characteristics.
Evaluating lock-based protocols for cooperation on XML documents
Authors: Helmer Sven , Kanne Carl-Christian , Moerkotte Guido
Published: November 2005

We discuss four different core protocols for synchronizing access to and modifications of XML document collections. These core protocols synchronize structure traversals and modifications. They are meant to be integrated into a native XML base management System (XBMS) and are based on two phase locking. We also demonstrate the different degrees of cooperation that are possible with these protocols by various experimental results. Furthermore, we also discuss extensions of these core protocols to full-fledged protocols. Further, we show how to achieve a higher degree of concurrency by exploiting the semantics expressed in Document Type Definitions (DTDs).
A context-aware methodology for very small data base design
Authors: Bolchini C. , Schreiber F. A. , Tanca L.
Published: November 2005

The design of a Data Base to be resident on portable devices and embedded processors for professional systems requires considering both the device memory peculiarities and the mobility aspects, which are an essential feature of the embedded applications. Moreover, these devices are often part of a larger Information System, comprising fixed and mobile resources. We propose a complete methodology for designing Very Small Data Bases, from the identification of the device resident portions down to the choice of the physical data structure, optimizing the cost and power consumption of the Flash memory, which - in the greatest generality - constitutes the permanent storage of the device.
Entity-Relationship modeling revisited
Authors: Badia Antonio
Published: November 2005

In this position paper, we argue the modern applications require databases to capture and enforce more domain semantics than traditional applications. We also argue that the best way to incorporate additional semantics into database systems is by capturing the added information in conceptual models and then using it for database design. In this light, we revisit Entity-Relationship models and investigate ways in which such models could be extended to play a role in the process. Inspired by a paper by Rafael Camps Pare ([2]), we suggest avenues of research in the issue.
Reconsidering Multi-Dimensional schemas
Authors: Martyn Tim
Published: November 2005

This paper challenges the currently popular "Data Warehouse is a Special Animal" philosophy and advocates that practitioners adopt a more conservative "Data Warehouse=Database" philosophy. The primary focus is the relevancy of Multi-Dimensional logical schemas. After enumerating the advantages of such schemas, a number of caveats to the presumed advantages are identified. The paper concludes with guidelines and commentary on implications for data warehouse design methodologies.
String storage and searching for data base applications
Authors: Copeland George P.
Published: November 2005

User and hardware cost trends dictate that data base systems should provide more complete functionality, simplicity of use, and reliability by increasing the amount of hardware present in the system. These goals are accomplished with a simple hardware arrangement within a one-dimensional cellular storage system called INDY. The INDY backend kernel is intended as a powerful tool for implementing all data models. The INDY cellular storage array is intended to provide functionality that is difficult to implement efficiently using a conventional hardware arrangement. It allows a simple implementation of improved data independence at high speeds. INDY simultaneously satisfies the time windows of future hardware technologies and user requirements.The importance of strings as a mechanism for defining abstract data types for data base languages is discussed in more detail in another paper. In that paper, a language called STRING is introduced which allows names of data objects to be semantically defined as variable-length strings and compared based on string pattern membership. This paper is concerned with the implementation of string storage and searching required by the STRING language. Implementation of higher level structures and searching requirements (such as sets, rows, tables and hierarchies) on the INDY kernel is treated elsewhere.
Text file inversion
Authors: Bird R. M. , Newsbaum J. B. , Trefftzs J. L.
Published: November 2005

This paper compares inversion of text files with inversion of more structured records. The unique characteristics of textual data which restrict the utility of inversion are identified and discussed. Inversion is shown to be useful only for small, static data bases, and when full text search is not required.
Coordinating concurrent access in a distributed database architecture
Authors: Stucki M. J. , Cox J. R. , Roman G. C. , Turcu P. N.
Published: November 2005

A distributed architecture for an interactive information system is described, and a scheme for coordinating concurrent access to its data is presented. The scheme is deadlock free and is carried out without the need for centralized control. Conflicts are detected as they occur, and competing processes are given exclusive access to the data they need.
Functional parallelism in an operand state saving computer
Authors: Harvill J. B.
Published: November 2005

Multiple, high-level operators are assigned to a general operand. The operators are implemented with individual micro-processors and are "attached" dynamically to the memory location representing the "current" value of the operand. The operators then asynchronously use each new operand value as it is stored and perform their operations in parallel. The proposed architecture represents a true M I S D (Multiple Instruction Stream - Single Data Stream) computer. Its architecture can provide effective parallelism and reduced programming complexity for a large class of both numeric and non-numeric computer problems.
The use of a database machine for supporting relational databases
Authors: Banerjee Jayanta , Hsiao David K.
Published: November 2005

One of the goals in the design of database machines of the future is their generality. In addition to being capable of carrying out the common database management functions with high reliability and performance, some of these machines are intended to support more than one data model. A specific database machine, known as the DBC, is intended to support several existing data models. Although the DBC supports many data models, we single out the relational data model for this discussion. In particular, we have tried to concentrate mainly on the subject of database representation and query translation of System R-like database management systems. Some estimates of the storage requirements and performance gains are given in this paper. However, due to limited space, the detailed analysis is shown elsewhere in [22].
Virtual information in data-base systems
Authors: Folinus Jeffery J. , Madnick Stuart E. , Schutzman Howard B.
Published: November 2005

This paper examines the concept and implications of virtual information in data base systems. Virtual information is any fact which does not physically exist in the data base, but is nonetheless accessible through combinations of algorithms and other data. Physically recorded information is only one of a number of ways to obtain information from a data-base system. Viewing an information system as a collection of functions shows that pure data and pure algorithm from the endpoints of a spectrum of ways function values can be realized, with the middle range being various types of virtual information. Several classes of virtual information are identified, and their usefulness is examined to show the appropriateness of the concept in a data-base system. Finally, the model is evaluated in light of the implications of virtual information for inference and automatic restructuring within a data base.
A progress report on the activities of the CODASYL End User Facility Task Group
Authors: Lefkovits Henry C.
Published: November 2005

This technical report is authored and presented by the End User Facility Task Group of the CODASYL Systems Committee to interested members of the computing community for discussion and comment. Stated in the report are the collective opinions of the committee members. The report does not necessarily represent the technical opinion of any one member, nor does it imply an unanimous opinion. This report neither states the opinion of, nor implies the support of, the sponsoring organizations. It is the intent of CODASYL that its work be available and in the public domain. Anyone reproducing all or part of this report is requested to include this notice where meaningful.
Database management systems on a multi-computer computer
Authors: Sinutko M.
Published: November 2005

This paper discusses fitting a database and database management system onto a particular research status computer constructed of a large array or network of closely-connected component computers. The findings may have application to other distributed computer architectures.
Data descriptive languages
Authors: Mooers Calvin N.
Published: November 2005

"Data" is defined as being digital matter having utility. A "data descriptive language" is a manner of description of how such digital matter can be transformed into a more useful form. Data descriptive languages are characterized as being iconographic, algorithmic, or a mixture of both. File structures are held to be merely a special case of data. An algorithmic data description is always possible, by definition, since otherwise the digital matter under consideration is not "data". In a trivial sense, such languages as COBOL or FORTRAN are found to be completely general data descriptive languages, although they are otherwise quite unsuitable because they are so poorly fitted to the descriptive task. A good data descriptive language should be congenial to use, general, transformable, and independent of supporting hardware or software. The value of small one-man projects for the creation of data languages is suggested.
Meta-database architecture for relational DBMS
Authors: Kilov Kn. I. , Popova I. A.
Published: November 2005

The architecture of an implementable relational DBMS is discussed, the meta-database for which is organized in the form of a set of text tables. Methodology for working with text is shown (including automatic coding), as well as semantic text control. A schematic example of a meta-database is shown.
Problems of optimistic concurrency control in distributed database systems
Authors: Schlageter G.
Published: November 2005

In [SCH81] some aspects of optimistic concurrency control (CC) in distributed database systems have been discussed, some important problems have, however, not been dealt with in sufficient detail in the paper but only in the oral presentation. Thus, the reader of the conference proceedings might get the impression that optimistic CC, as introduced in [KUR79], is very easily adapted to distributed systems. Unfortunately, when looking into the problem more thoroughly, the contrary turns out to be true. This note is meant to highlight the main problems of optimistic CC in distributed database systems. We cannot discuss possible solutions in detail - this will be done elsewhere.
Distributed processing of data dynamics
Authors: Rolland Colette , Richard Christian
Published: November 2005

We are concerned by distributed data base (DDB) consistency. We claim that a better DDB consistency requires to integrate in Distributed Base Management Systems a system of automata to manage its dynamics processing according to the description of data dynamics. We present a specification language in order to allow the dynamics DDB description according to the data dynamics modeling presented at the 4th VLDB Conference. We develop the system of automata able to perform in a distributed way the DDB dynamics processing and discuss the solution from concurrency and consistency points of view.
Administering a distributed Data Base Management System
Authors: Walker Henry M.
Published: November 2005

The early design of a Data Base Management System (DBMS) must include a specification of the functions associated with administering the system, so that subsequent activities, such as documentation, training, and staffing, can occur. Therefore, this paper undertakes a careful definition of administrative tasks for a Data Base Management System (DBMS) in a distributed computer environment. The paper first discusses a general framework for administering a distributed DBMS, and then the paper presents a specific listing of administrative functions. While the above work is based on a specific system under development at Bell Laboratories, the paper concludes with several comments extending this work to other types of distributed systems.
On some arguable claims in B. Shneiderman's evaluation of natural language interaction with database systems
Authors: Rowe Neil C.
Published: November 2005

This work is part of the Knowledge Base Management Systems Project, under contract #N00039-80-G-0132 from the Defense Advanced Research Projects Agency of the United States Department of Defense. The views and conclusions contained in this document are those of the author and should not be interpreted as representative of the official policies of DARPA or the US Government.
Why sort-merge gives the best implementation of the natural join
Authors: Merrett T. H.
Published: November 2005

To join two relations efficiently, they must not only be clustered but
mutually clustered
. Sorting is the only known way to achieve mutual clustering. Once the relations are sorted, merging is the obvious way to implement the join. If the relations are known to be sorted appropriately, the most costly part of the process can be omitted. To know that a relation is sorted already, it is best to remember that we sorted it. Otherwise detecting that the relation is sorted requires inspection of each tuple, a cost comparable in many cases to the cost of sorting. Detecting any other form of mutual clustering is bound to be a combinatorial process of much greater cost than sorting. Cheaper forms of detection may be possible using sampling, but these are heuristics at best and there is no reliable foundation for them.It is assumed that the sizes of the relations are large compared with the RAM memory available or, equivalently, compared with the number of processors available. Our conclusion that sort-merge is best is thus applicable to single-processor computers or to multiple-processor database machines. Discussing the cost of joining relations without making this assumption is outside the subject of databases.
Comparison of four relational data model specifications
Authors: Lamersdorf Winfried
Published: November 2005

This paper reviews four different approaches to specifying the relational data model which are written at about the same time:1. the 'Definition and Formalization of the Relational Data Model' as provided as part of the final ANSI/X3/SPARC/DBSSG Relational Database Task Group Report,2. the 'Relational Database Model Specifications' as submitted to the National Bureau of Standards by the Computer Corporation of America as a draft report in October 1981,3. the 'Formal Definition of the Relational Model' as specified by C. Date of IBM, San Jose, and4. the specification of the relational data model which is expressed in terms of the 'Positional Set Notation' as given in the 'Abstract Database Model' project of the National Bureau of Standards in October 1981.The paper points out some of the differences between the four approaches to specifying the RDM semantics.
A critique of the SQL database language
Authors: Date C. J.
Published: November 2005

The ANS Database Committee (X3H2) is currently at work on a proposed standard relational database language (RDL), and has adopted as a basis for that activity a definition of the "structured query language" SQL from IBM [10]. Moreover, numerous hardware and software vendors (in addition to IBM) have already released or at least announced products that are based to a greater or lesser extent on the SQL language as defined by IBM. There can thus be little doubt that the importance of that language will increase significantly over the next few years. Yet the SQL language is very far from perfect. The purpose of this paper is to present a critical analysis of the language's major shortcomings, in the hope that it may be possible to remedy some of the deficiencies before their influence becomes too all-pervasive. The paper's standpoint is primarily that of formal computer languages in general, rather than that of database languages specifically.
The organizational and informational context of large business system integration projects
Authors: Mattison Robert M.
Published: November 2005

Many computer systems today have evolved into hybrids of assorted subsystems. This assortment can include systems of disparate technologies(batch, data base ...), hardware configurations and of different chronological ages.As managers try to 'forge' these hybrids into homogeneous, integrated systems, they are discovering that integration means more then simply the physical compatability of its component parts.Standardized protocols, gateway machines, and translation strategies can help, but after all of these 'physical' incompatabilities are resolved, a much larger problem, the problem of informational and organizational integration becomes apparent.When the practioner of large BUSINESS systems design attempts to apply readily available theory to these issues, he finds that his challenge is not only to 'solve' data management problems, but to 'uncover' what the real problems are when applied against the backdrop of business organizations and their often contradictory informational needs.The author proposes that this problem definition process can be greatly facilitated by a better understanding of the business's organizational environment and its relationship to the computer environment.By examining the organization itself as an information gathering/distributing system, the individuals' needs for information are described in terms of information requirements. Computer system organization, data storage and access methods are then evaluated in terms of their ability to meet those informational needs efficiently.Finally, an approach to large system integration based upon these informational requirements is proposed.
An unnormalized relational data model based on user views
Authors: Pernul G.
Published: November 2005

A description of a database design method according to user views is introduced. The database schema is decomposed by applying the operators: horizontal decomposition, vertical decomposition and derived horizontal decomposition. Resulting fragments (= effects of the decomposition) are controlled by a central Data Dictionary, consisting of two subschemata, the Application Subschema and the Data Subschema.
Overexpression of the insulin receptor inhibitor PC-1/ENPP1 induces insulin resistance and hyperglycemia
Authors: Maddux Betty A. , Chang Yow-Ning , Accili Domenico , McGuinness Owen P. , Youngren Jack F. , Goldfine Ira D.
Published: November 2005

The ectoenzyme PC-1 is an insulin receptor inhibitor that is elevated in cells and tissues of humans with type 2 diabetes (T2D). We have recently shown that acute PC-1 overexpression in liver causes insulin resistance and glucose intolerance in mice ( 3 ), but the chronic effects of PC-1 overexpression on these functions are unknown. Herein we produced transgenic mice overexpressing the potent q allele of human PC-1 in muscle and liver. Compared with controls, these mice had 2- to 3-fold elevations of PC-1 content in liver and 5- to 10-fold elevations in muscle. In the fed state, the PC-1 animals had 100 mg/dl higher glucose levels and sixfold higher insulin levels compared with controls. During glucose tolerance tests, these PC-1 animals had peak glucose levels that were >150 mg/dl higher than controls. In vivo uptake of 2-deoxy-d-glucose in muscle during insulin infusion was decreased in the PC-1 animals. These in vivo data support the concept, therefore, that PC-1 plays a role in insulin resistance and hyperglycemia and suggest that animals with overexpression of human PC-1 in insulin-sensitive tissues may be important models to investigate insulin resistance.
Thermogenic responsiveness to nonspecific β-adrenergic stimulation is not related to genetic variation in codon 16 of the β2-adrenergic receptor
Authors: Bell Christopher , Stob Nicole R. , Seals Douglas R.
Published: November 2005

Stimulation of β-adrenergic receptors (β-AR) by the sympathetic nervous system (SNS) modulates energy expenditure (EE), but substantial interindividual variability is observed. We determined whether the thermogenic response to β-AR stimulation is related to genetic variation in codon 16 of the β2-AR, a biologically important β-AR polymorphism, and whether differences in SNS activity (i.e., the stimulus for agonist-promoted downregulation) are involved. The increase in EE (ΔEE, indirect calorimetry, ventilated hood) above resting EE in response to nonspecific β-AR stimulation [iv isoproterenol: 6, 12, and 24 ng/kg fat-free mass (FFM)/min] was measured in 46 healthy adult humans [Arg16Arg: 9 male, 7 female, 48 ± 5 yr; Arg16Gly: 11 male, 4 female, 53 ± 5 yr; Gly16Gly: 3 male, 12 female, 48 ± 5 yr (means ± SE)]. Neither FFM-adjusted baseline resting EE ( P = 0.83) nor the dose of isoproterenol required to increase EE 10% above resting ( P = 0.87) differed among the three groups (Arg16Arg: 5,409 ± 209 kJ/day, 11.2 ± 2.1 ng·kg FFM−1·min−1; Arg16Gly: 5,367 ± 272 kJ/day, 11.1 ± 2.1 ng·kg FFM−1·min−1; Gly16Gly: 5,305 ± 159 kJ/day, 10.5 ± 1.4 ng·kg FFM−1·min−1). Consistent with this, muscle sympathetic nerve activity and plasma norepinephrine concentrations were not different among the groups. Group differences in sex composition did not influence the results. Our findings indicate that the thermogenic response to nonspecific β-AR stimulation, an important mechanistic component of overall β-AR modulation of EE, is not related to this β2-AR polymorphism in healthy humans. This may be explained in part by a lack of association between this gene variant and tonic SNS activity.
Effect of p47phoxgene deletion on ROS production and oxygen sensing in mouse carotid body chemoreceptor cells
Authors: He L. , Dinger B. , Sanders K. , Hoidal J. , Obeso A. , Stensaas L. , Fidone S. , Gonzalez C.
Published: November 2005

Membrane potential in oxygen-sensitive type I cells in carotid body is controlled by diverse sets of voltage-dependent and -independent K+channels. Coupling of Po2to the open-closed state of channels may involve production of reactive oxygen species (ROS) by NADPH oxidase. One hypothesis suggests that ROS are produced in proportion to the prevailing Po2and a subset of K+channels closes as ROS levels decrease. We evaluated ROS levels in normal and p47phoxgene-deleted [NADPH oxidase knockout (KO)] type I cells using the ROS-sensitive dye dihydroethidium (DHE). In normal cells, hypoxia elicited an increase in ROS, which was blocked by the specific NADPH oxidase inhibitor 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF, 3 mM). KO type I cells did not respond to hypoxia, but the mitochondrial uncoupler azide (5 μM) elicited increased fluorescence in both normal and KO cells. Hypoxia had no effect on ROS production in sensory and sympathetic neurons. Methodological control experiments showed that stimulation of neutrophils with a cocktail containing the chemotactic peptide N-formyl-Met-Leu-Phe (1 μM), arachidonic acid (10 μM), and cytochalasin B (5 μg/ml) elicited a rapid increase in DHE fluorescence. This response was blocked by the NADPH oxidase inhibitor diphenyleneiodonium (10 μM). KO neutrophils did not respond; however, azide (5 μM) elicited a rapid increase in fluorescence. Physiological studies in type I cells demonstrated that hypoxia evoked an enhanced depression of K+current and increased intracellular Ca2+levels in KO vs. normal cells. Moreover, AEBSF potentiated hypoxia-induced increases in intracellular Ca2+and enhanced the depression of K+current in low O2. Our findings suggest that local compartmental increases in oxidase activity and ROS production inhibit the activity of type I cells by facilitating K+channel activity in hypoxia.
Activation of endothelial NADPH oxidase during normoxic lung ischemia is KATP channel dependent
Authors: Zhang Qunwei , Matsuzaki Ikuo , Chatterjee Shampa , Fisher Aron B.
Published: November 2005

Previous studies have shown endothelial cell membrane depolarization and generation of reactive oxygen species (ROS) in endothelial cells with abrupt reduction in shear stress (ischemia). This study evaluated the role of ATP-sensitive potassium (KATP) channels and NADPH oxidase in the ischemic response by using Kir6.2−/− and gp91phox−/− mice. To evaluate ROS generation, we subjected isolated perfused mouse lungs labeled with 2′,7′-dichlorodihydrofluorescein (DCF), hydroethidine (HE), or diphenyl-1-pyrenylphosphine (DPPP) to control perfusion followed by global ischemia. In wild-type C57BL/6J mice, imaging of subpleural endothelial cells showed a time-dependent increase in intensity for all three fluorescence probes with ischemia, which was blocked by preperfusion with cromakalim (a KATP channel agonist) or diphenyleneiodonium (DPI, a flavoprotein inhibitor). Endothelial cell fluorescence with bis-oxonol, a membrane potential probe, increased during lung ischemia indicating cell membrane depolarization. The change in membrane potential with ischemia in lungs of gp91phox−/− mice was similar to wild type, but ROS generation did not occur. Lungs from Kir6.2−/− showed marked attenuation of the change in both membrane potential and ROS production. Thus membrane depolarization during lung ischemia requires the presence of a KATP channel and is required for activation of NADPH oxidase and endothelial ROS generation.
A Quartet Neural System Model Orchestrating Sleep and Wakefulness Mechanisms
Authors: Tamakawa Yuichi , Karashima Akihiro , Koyama Yoshimasa , Katayama Norihiro , Nakao Mitsuyuki
Published: November 2005

Physiological knowledge of the neural mechanisms regulating sleep and wakefulness has been advanced by the recent findings concerning sleep/wakefulness-related preoptic/anterior hypothalamic and perifornical (orexin-containing)/posterior hypothalamic neurons. In this paper, we propose a mathematical model of the mechanisms orchestrating a quartet neural system of sleep and wakefulness composed of the following: 1) sleep-active preoptic/anterior hypothalamic neurons (N-R group); 2) wake-active hypothalamic and brain stem neurons exhibiting the highest rate of discharge during wakefulness and the lowest rate of discharge during paradoxical or rapid eye movement (REM) sleep (WA group); 3) brain stem neurons exhibiting the highest rate of discharge during REM sleep (REM group); and 4) basal forebrain, hypothalamic, and brain stem neurons exhibiting a higher rate of discharge during both wakefulness and REM sleep than during nonrapid eye movement (NREM) sleep (W-R group). The WA neurons have mutual inhibitory couplings with the REM and N-R neurons. The W-R neurons have mutual excitatory couplings with the WA and REM neurons. The REM neurons receive unidirectional inhibition from the N-R neurons. In addition, the N-R neurons are activated by two types of sleep-promoting substances (SPS), which play different roles in the homeostatic regulation of sleep and wakefulness. The model well reproduces the actual sleep and wakefulness patterns of rats in addition to the sleep-related neuronal activities across state transitions. In addition, human sleep-wakefulness rhythms can be simulated by manipulating only a few model parameters: inhibitions from the N-R neurons to the REM and WA neurons are enhanced, and circadian regulation of the N-R and WA neurons is exaggerated. Our model could provide a novel framework for the quantitative understanding of the mechanisms regulating sleep and wakefulness.
Epileptogenesis Is Associated With Enhanced Glutamatergic Transmission in the Perforant Path
Authors: Scimemi Annalisa , Schorge Stephanie , Kullmann Dimitri M. , Walker Matthew C.
Published: November 2005

The perforant path provides the main excitatory input into the hippocampus and has been proposed to play a critical role in the generation of temporal lobe seizures. It has been hypothesized that changes in glutamatergic transmission in this pathway promote the epileptogenic process and seizure generation. We therefore asked whether epileptogenesis is associated with enhanced glutamatergic transmission from the perforant path to dentate granule cells. We used a rat model of temporal lobe epilepsy in which spontaneous seizures occur after an episode of pilocarpine-induced status epilepticus. Whole cell patch-clamp recordings were obtained from dentate granule cells in hippocampal slices from control and epileptic animals 3 wk after pilocarpine-induced status epilepticus. The paired pulse ratio of perforant path-evoked AMPA receptor-mediated excitatory postsynaptic currents (EPSCs) was reduced in tissue obtained from epileptic rats. This is consistent with an increase in release probability. N-methyl-d-aspartate (NMDA) receptor-mediated EPSCs were also prolonged. This prolongation could not be accounted for by decreased activity of glutamate transporters or by a change in NMDA receptor subunit composition in dentate granule cells, implying a change in NMDA receptor kinetics. This change in NMDA receptor kinetics was associated with the emergence of significant synaptic cross-talk, detected as a use-dependent block of receptors activated by medial perforant path synapses after lateral perforant path stimulation in MK-801. Enhanced glutamatergic transmission and the emergence of cross-talk among perforant path-dentate granule cell synapses may contribute to lowering seizure threshold.
Visceral Adiposity and Apolipoprotein C-III in Apolipoprotein B-Containing Lipoproteins Are Independent Predictors in Determining Atherogenic Lipid Profiles
Authors: Han Taekyong , Woo Sang-Koo , Shin Seonae , Kang Hyun-Sik
Published: November 2005

Background/Aims: Little is known about how visceral adiposity and apolipoprotein CIII in apoB-containing lipoproteins influence atherogenic lipids profiles. The purpose of this study was to determine the relationships of visceral adiposity and apoC-III in apoB-containing lipoproteins (LpB:C-III) with lipoprotein lipids in circulating plasma. Methods: A subgroup of 46 men (n = 20, aged 29.1–33.4 years) and women (n = 26, aged 29.1–33.8 years) were recruited from an ongoing population study at our institution. Anthropometric variables including weight, height, and waist circumference were measured using standard procedures, and body mass index was calculated (kg/m2). Visceral adipose tissue (VAT) was measured with magnetic resonance imaging. Plasma apolipoproteins, lipids, glucose, and insulin were measured after an overnight fasting. Results: The men had a significantly higher waist circumference, glucose, and TC/HDL-C ratio, while the women had a significantly higher HDL-C and apoA-I. In particular, this is the first study to report that VAT and LpB:C-III were independent predictors in determining plasma triglyceride concentrations. Conclusion: The relations of plasma triglyceride concentration with VAT and LpB:C-III suggest that information on VAT and apoC-III in apoB-containing lipoproteins may provide additional information on the atherogenic lipid profiles.
Endogenous Hypertriglyceridemia Intensifies the Course of Cerulein-Induced Pancreatitis in Rat: Relation with Changes in the VLDL Composition
Authors: Ponzo O. , Schreier L. , Resnik R. , Negri G. , Scacchi P. , Cresta M.A. , Wikinski R.
Published: November 2005

Aims: To study if the course of cerulein-induced pancreatitis in rats changes in a state of triglyceride-rich lipoprotein metabolism alteration. Methods: Two groups of rats received control diet during a 90-day period (A) and sucrose-rich diet to induce endogenous hypertriglyceridemia (B). Subgroups A2 and B2 received i.p. 45 µg cerulein/kg body weight (to induce acute pancreatitis). Histological examination of pancreas tissue, serum pancreatic lipase, lipoprotein profile and VLDL chemical composition were assessed. Then, pancreatic lipase hydrolytic activity on VLDL-triglycerides was evaluated in vitro. Results: Cellular vacuolization was observed in all of the cerulean-injected rats, but only in subgroup B2 fat necrosis was present. Serum triglycerides were higher in subgroup B1 than in subgroup A1 (mean ± SEM, mg/dl 123,77 ± 25.7 vs. 65.8 ± 7, p < 0.01). Triglycerides from rats fed with sucrose-rich diet, decreased after cerulein-induced pancreatitis (80.38 ± 11.3 vs. 123,77 ± 25.7, p < 0.02). Moreover, the endogenous hypertriglyceridemic rats showed an increment of VLDL triglyceride content, which decreased when rats were injected with cerulein. A negative correlation was found between VLDL-triglyceride content and serum pancreatic lipase activity (r = 0.58, p < 0.02). The in vitro assay showed a decrease in VLDL-triglyceride content post incubation with pancreatic lipase enriched serum (mean ± SD: 59.2 ± 27.7%, p < 0.01). Conclusions: The endogenous hypertriglyceridemia intensifies the course of cerulein-induced pancreatitis and it could be related to the decrease in VLDL-triglycerides as a consequence of pancreatic lipase hydrolytic activity.
Transcranial Doppler in Adult Patients with Sickle Cell Disease
Authors: Sampaio Silva Gisele , Vicari Perla , Figueiredo Maria Stella , Filho Adauto Castelo , Valadi Nojan , Massaro Ayrton Roberto
Published: November 2005

Background: Transcranial Doppler (TCD) is the key test in determining the need for prophylactic blood transfusion to prevent stroke in children with sickle cell disease (SCD). The role of TCD in assessing stroke risk in adults with SCD as well as the pattern of TCD velocities in these patients are still undetermined. Methods: The authors compared TCD velocities in SCD adults (n = 56) with those of healthy controls (n = 56). Results: Velocities in SCD adults were lower than those found in children and higher than in controls and negatively correlated to hematocrit in both groups. Conclusion: The pattern of TCD velocities in adults with SCD is different from that described in children. Age-specific TCD criteria may assist the detection of stroke risk in these patients.
Insular Involvement Is Associated with QT Prolongation: ECG Abnormalities in Patients with Acute Stroke
Authors: Tatschl Claudia , Stöllberger Claudia , Matz Karl , Yilmaz Nilgün , Eckhardt Raoul , Nowotny Monika , Dachenhausen Alexandra , Brainin Michael
Published: November 2005

Purpose: Aim was to assess the frequencies of electrocardiographic (ECG) abnormalities, including QT prolongation, in acute stroke patients and their association with stroke severity, stroke subtype and location, and cardiovascular risk factors. Methods: Prospectively, admission 12-lead ECG findings, stroke characteristics, cardiovascular risk factors, and potential QT-prolonging factors were collected in 122 consecutive patients with acute stroke. Results: Eighty-four patients (69%) had ECG abnormalities, most frequently ST changes in 34%, QT prolongation in 31%, and atrial fibrillation in 27% of them. Insular involvement and prior stroke independently predicted QT prolongation in small infarcts (insular involvement OR 0.12, 95% CI 0.02–0.74, p = 0.022; prior stroke OR 0.20, 95% CI 0.06–0.70, p = 0.012). Conclusion: Continuous ECG monitoring and assessment of the QT interval should be mandatory in patients with acute stroke.
Selected Observations on Amusia
Authors: Pearce J.M.S.
Published: November 2005

Amusia appears primarily as a defect in processing pitch. The deficit extends to musical memory and recognition, singing and timing of music. Clinical studies of acquired brain lesions show that dysphasia is not necessarily accompanied by amusia, and acquired amusia without aphasia has been reported. These dissociations suggest some degree of autonomy in the function of these mechanisms.
Extraordinary Flood Response of a Small Urban Watershed to Short-Duration Convective Rainfall
Authors: Smith James A. , Miller Andrew J. , Baeck Mary Lynn , Nelson Peter A. , Fisher Gary T. , Meierdiercks Katherine L.
Published: November 2005

The 9.1 km2 Moores Run watershed in Baltimore, Maryland, experiences floods with unit discharge peaks exceeding 1 m3 s−1 km−2 12 times yr−1, on average. Few, if any, drainage basins in the continental United States have a higher frequency. A thunderstorm system on 13 June 2003 produced the record flood peak (13.2 m3 s−1 km−2) during the 6-yr stream gauging record of Moores Run. In this paper, the hydrometeorology, hydrology, and hydraulics of extreme floods in Moores Run are examined through analyses of the 13 June 2003 storm and flood, as well as other major storm and flood events during the 2000–03 time period. The 13 June 2003 flood, like most floods in Moores Run, was produced by an organized system of thunderstorms. Analyses of the 13 June 2003 storm, which are based on volume scan reflectivity observations from the Sterling, Virginia, WSR-88D radar, are used to characterize the spatial and temporal variability of flash flood producing rainfall. Hydrology of flood response in Moores Run is characterized by highly efficient concentration of runoff through the storm drain network and relatively low runoff ratios. A detailed survey of high-water marks for the 13 June 2003 flood is used, in combination with analyses based on a 2D, depth-averaged open channel flow model (TELEMAC 2D) to examine hydraulics of the 13 June 2003 flood. Hydraulic analyses are used to examine peak discharge estimates for the 13 June flood peak, propagation of flood waves in the Moores Run channel, and 2D flow features associated with channel and floodplain geometry.