Browsing Unix directories with dynamic queries: An analytical and experimental evaluation - Liao,H.; Osada,M.; Shneiderman, Ben (Proc. Ninth Japanese Symp. Human Interface, 1993)
We designed, implemented, and evaluated an innovative concept for dynamic queries which involves the direct manipulation of small databases. Our domain was directories in a Unix file system. Dynamic queries allow users to formulate queries and explore the databases with graphical widgets, such as sliders and buttons, without requiring them to have any knowledge about the underlying structure of the database query languages, or command language syntax. Three interfaces for presenting directories were developed and tested with eighteen subjects in a within-subject design. The results of the formative evaluation yielded some useful guidelines for software designers.

Building HCI partnerships and infrastructure - Shneiderman, Ben; LEWIS,CLAYTON (Behaviour & Information Technology, 1993)
As policymakers and technology planners respond to the growing activity in human?computer interaction, a broad perspective may be helpful. This article offers a top-down view of current activities and suggests opportunities and challenges for the continued growth of HCI. Partnerships among universities, corporations, government agencies, and professional societies are proposed. Infrastructure needs to support this new discipline are outlined.Abstract As policymakers and technology planners respond to the growing activity in human?computer interaction, a broad perspective may be helpful. This article offers a top-down view of current activities and suggests opportunities and challenges for the continued growth of HCI. Partnerships among universities, corporations, government agencies, and professional societies are proposed. Infrastructure needs to support this new discipline are outlined.

Building Partnerships and Infrastructure - Shneiderman, Ben; Lewis,C. (Communications of the ACM, 1993)
As policymakers and technology planners respond to the growingactivity in human-computer interaction, a broad perspective may be helpful. This article offers a top-down view of current activities and suggests opportunities and challenges for the continued growth of HCI. Partnerships among universities, corporations, government agencies, and professional societies are proposed. Infrastructure needs to support this new discipline are outlined.

Coupling production systems and database systems: A homogeneous approach - Sellis,T.; Lin,C. C; Raschid, Louiqa (Knowledge and Data Engineering, IEEE Transactions on, 1993)

Facilitating Data Exploration: Dynamic Queries On A Health Statistics Map - Plaisant, Catherine; Laboratory,Human-computer Interaction (Proc. of the Government Statistics Section, Annual Meeting of the American Statistical Assoc. Conf. Proc, pg, 1993)
: Users with no specialized computer training are often discouraged by the complex syntax of query languages and the output of long tables of alphanumerical values. The Human-Computer Interaction Laboratory has recently developed the concept of dynamic queries which allows user control of animated visual displays of information. Experiments with our first applications have shown that dynamic queries can help reveal trends or global properties as well as assist users in answering specific questions. We present a new application developed with the National Center for Health Statistics and running on a simple PC. A thematic map of the United States is animated by adjusting sliders displayed on the side of the map. A time slider illustrates time trends. The other sliders control the filtering out of areas of the map according to parameters such as demographics. Detailed data about a particular area is obtained by clicking directly on its location on the map. We have received encouraging fe...

Scheduling synchronous dataflow graphs for efficient looping - Bhattacharyya, Shuvra S.; Lee,E. A (The Journal of VLSI Signal Processing, 1993)

Species-specific signals for the splicing of a short Drosophila intron in vitro. - Guo,M.; Lo,P. C.; Mount, Stephen M. (Molecular and Cellular BiologyMol. Cell. Biol., 1993)
The effects of branchpoint sequence, the pyrimidine stretch, and intron size on the splicing efficiency of the Drosophila white gene second intron were examined in nuclear extracts from Drosophila and human cells. This 74-nucleotide intron is typical of many Drosophila introns in that it lacks a significant pyrimidine stretch and is below the minimum size required for splicing in human nuclear extracts. Alteration of sequences of adjacent to the 3' splice site to create a pyrimidine stretch was necessary for splicing in human, but not Drosophila, extracts. Increasing the size of this intron with insertions between the 5' splice site and the branchpoint greatly reduced the efficiency of splicing of introns longer than 79 nucleotides in Drosophila extracts but had an opposite effect in human extracts, in which introns longer than 78 nucleotides were spliced with much greater efficiency. The white-apricot copia insertion is immediately adjacent to the branchpoint normally used in the splicing of this intron, and a copia long terminal repeat insertion prevents splicing in Drosophila, but not human, extracts. However, a consensus branchpoint does not restore the splicing of introns containing the copia long terminal repeat, and alteration of the wild-type branchpoint sequence alone does not eliminate splicing. These results demonstrate species specificity of splicing signals, particularly pyrimidine stretch and size requirements, and raise the possibility that variant mechanisms not found in mammals may operate in the splicing of small introns in Drosophila and possibly other species.

Two dimensional pattern matching in a digitized image - Landau,G.; Vishkin, Uzi (Combinatorial Pattern Matching, 1993)

Using Synthetic-Perturbation Techniques for Tuning Shared Memory Programs - Snelick,Robert; JaJa, Joseph F.; Kacker,Raghu; Lyon,Gordon (Parallel Processing, 1993. ICPP 1993. International Conference on, 1993)
The Synthetic-Perturbation Tuning (SPT) methodology is base d on compirical approach that introduces artificial delays into the MIMD program and captures the effects of such delays by using the modrn branch statistics called design of experiments.

Anthropomorphism: from Eliza to Terminator 2 - Don,Abbe; Brennan,Susan; Laurel,Brenda; Shneiderman, Ben (Proceedings of the SIGCHI conference on Human factors in computing systems, 1992)

Building a lexicon for machine translation: use of corpora for aspectual classification of verbs - Dorr, Bonnie J; Lee,Ki (University of Maryland at College Park, 1992)

A connectionist approach to vertex covering problems - Peng,Y.; Reggia, James A.; Li,T. (Int’l J. Neural Systems, 1992)

The effects of time delays on a telepathology user interface. - Carr,D.; Hasegawa,H.; Lemmon,D.; Plaisant, Catherine (Proceedings of the Annual Symposium on Computer Application in Medical CareProc Annu Symp Comput Appl Med Care, 1992)
Telepathology enables a pathologist to examine physically distant tissue samples by microscope operation over a communication link. Communication links can impose time delays which cause difficulties in controlling the remote device. Such difficulties were found in a microscope teleoperation system. Since the user interface is critical to pathologist's acceptance of telepathology, we redesigned the user interface for this system, built two different versions (a keypad whose movement commands operated by specifying a start command followed by a stop command and a trackball interface whose movement commands were incremental and directly proportional to the rotation of the trackball). We then conducted a pilot study to determine the effect of time delays on the new user interfaces. In our experiment, the keypad was the faster interface when the time delay is short. There was no evidence to favor either the keypad or trackball when the time delay was longer. Inexperienced participants benefitted by allowing them to move long distances over the microscope slide by dragging the field-of-view indicator on the touchscreen control panel. The experiment suggests that changes could be made to the trackball interface which would improve its performance.

Efficient pattern matching with scaling - Amir, A.; Landau,G. M; Vishkin, Uzi (Journal of Algorithms, 1992)

A formative evaluation of three interfaces for browsing directories using dynamic queries - Liao,H.S.; Osada,M.; Shneiderman, Ben (University of Maryland, Center for Automation Research, Computer Vision Laboratory, 1992)

Incrementally maintained network→relational database mapping - Mark,Leo; Roussopoulos, Nick; Newsome,Tina; Laohapipattana,Piriya (Software: Practice and Experience, 1992)
An incrementally maintained mapping from a network to a relational database is presented. This mapping may be established either to support the efficient retrieval of data from a network database through a relational interface, or as the first step in a gradual conversion of data and applications from a network to a relational database system. After the mapping has been established, the only data mapped from the network to the relational database are the increments resulting from updates on the network database. The mapping is therefore an efficient alternative to mappings that repeatedly map the results of retrievals through the relational interface from the network database to the relational database. This is in particular the case when the two databases reside on different hosts. Applications on the network database may, under certain restrictions, gradually be moved to the relational database, while the mapping incrementally maintains the relational database for the applications that remain on the network database.
Keywords: Database conversion; Database gateway; Database mapping; Incremental database mapping

VLSI Implementation of Real-Time Parallel DCT/DST Lattice Structures for Video - Chiu,Ching-Te; Kolagotla,Ravi K.; Liu,K. J. Ray; JaJa, Joseph F. (Institute for Systems Research, University of Maryland, College Park, 1992)
The alternate use [1] of the discrete cosine transform (DCT) and the discrete sine transform (DST) can achieve a higher data compression rate and less block effect in image processing. A parallel lattice structure that can dually generate the 1-D DCT and DST is proposed. We also develop a fully-pipelined 2-D DCT lattice architecture that consists of two 1-D DCT/DST arrays without transposition. Both architectures are ideally suited for VLSI implementation because they are modular, regular, and have only local interconnections. the VLSI implementation of the lattice module using the distributed arithmetic approach is described. This realization of the lattice module using 2 um CMOS technology can achieve an 80Mb/s data rate.
Keywords: Parallel architectures; Signal processing; Systems Integration; VLSI architectures

An algebra and calculus for relational multidatabase systems - Grant,J.; Litwin,W.; Roussopoulos, Nick; Sellis,T. (, First International Workshop on Interoperability in Multidatabase Systems, 1991. IMS '91. Proceedings, 1991)
With the existence of many autonomous databases widely accessible through computer networks, users will require the capability to jointly manipulate data in different databases. A multidatabase system provides such a capability through a multidatabase manipulation language. The authors propose a theoretical foundation for such languages by presenting a multirelational algebra and calculus based on the relational algebra and calculus. The proposal is illustrated by various queries on an example multidatabase
Keywords: Algebra; autonomous databases; Calculus; Computer networks; Computer science; Data models; Data structures; Database systems; database theory; distributed databases; Military computing; multidatabase manipulation language; multidatabase system; multirelational algebra; query languages; relational algebra; Relational databases; Spatial databases; theoretical foundation

Computer based systems engineering workshop - Lavi,J.; Agrawala, Ashok K.; Buhr,R.; Jackson,K.; Jackson,M.; Lang,B. (Software Engineering Education, 1991)
Modern computer based systems are complex multi-systems consisting of many connected individual subsystems; each one of them is typically also a multicomputer system. The subsystems in a multi-system can be either geographically distributed or locally connected systems. Typical examples of computer based systems are medical systems, process control systems, communications systems, weapon systems and large information systems.The development of these complex systems requires the establishment of a new engineering discipline in its own right, Computer Based Systems Engineering — CBSE. The definition of the discipline, its current and future practice and the ways to establish and promote it were discussed in an international IEEE workshop held in Neve-Ilan, Israel in May 1990. The major conclusion of the workshop was that CBSE should be established as a new field in its own right. To achieve this goal, the workshop participants recommended that the IEEE Computer Society shall set up a task force for the promotion of the field, the establishment of CBSE Institutes and the development of the educational framework of CBSE. The paper describes the major findings of the workshop that led to these conclusions and recommendations.

Semantics for update rule programs and implementation in a relational database management system - Raschid, Louiqa; Lobo,J. (ACM Transactions on Database Systems, 1991)

Trie hashing with controlled load - Litwin,W. A; Roussopoulos, Nick; Levy,G.; Hong,W. (IEEE Transactions on Software Engineering, 1991)
Trie hashing (TH), a primary key access method for storing and accessing records of dynamic files, is discussed. The key address is computed through a trie. A key search usually requires only one disk access when the trie is in core and two disk accesses for very large files when the trie must be on disk. A refinement to trie hashing, trie hashing with controlled load (THCL), is presented. It is designed to control the load factor of a TH file as tightly as that of a B-tree file, allows high load factor of up to 100% for ordered insertions, and increases the load factor for random insertions from 70% to over 85%. It is shown that these properties make trie hashing preferable to a B-tree
Keywords: B-tree file; Computer science; controlled load; Databases; disk access; dynamic files; file organisation; high load factor; information retrieval systems; key search; load factor; Military computing; ordered insertions; Predictive models; primary key access method; Protocols; random insertions; TH file; THCL; Tree data structures; trees (mathematics); trie hashing

Window control strategies for hypertext traversal: An empirical study - Lifshitz,J.; Shneiderman, Ben (Proc. 29th Annual ACM DC Technical Symposium, 1991)
Nowadays, larger and higher resolution screens supporting multiple windows are widely available. They are often used to traverse hypertext databases for fact retrieval, education or casual browsing. This paper describes a study comparing two methods of window control strategies for article placement in four, equal sized and tiled windows (By tiled we mean non-overlapping, non-movable and non-resizable windows, which together cover the entire screen.) The first placement strategy - Automatic Panning (A P) - was controlled by the system software and the second placement strategy - User Controlled Placement (UCP) - trasferred control to the users. The task required subjects to answer questions about the content of a hypertext. Statistical analysis shows that subjective preference was significantly higher and amount of backtracking was significantly lower for the user controlled placement. Speed differences did not prove to be significant, although there was consistent tendency favoring the automatic pa nning strategy.

[31] Fast alignment of DNA and protein sequences - Landau,G. M; Vishkin, Uzi; Nussinov,R. (Methods in Enzymology, 1990)

Drosophila melanogaster genes for U1 snRNA variants and their expression during development - Lo,Partick C. H.; Mount, Stephen M. (Nucleic Acids ResearchNucl. Acids Res., 1990)
We have cloned and characterized a complete set of seven U1-related sequences from Drosophila melanogaster. These sequences are located at the three cytogenetic loci 21D, 82E, and 95C. Three of these sequences have been previously studied: one U1 gene at 21D which encodes the prototype U1 sequence (U1a), one U1 gene at 82E which encodes a U1 variant with a single nucleotide substitution (1Mb), and a pseudogene at 82E. The four previously uncharacterized genes are another U1b gene at 82E, two additional U1 a genes at 95C, and a U1 gene at 95C which encodes a new variant (U1c) with a distinct single nucleotide change relative to U1a. Three blocks of 5′ flanking sequence similarity are common to all six full length genes. Using specific primer extension assays, we have observed that the 1Mb RNA is expressed in Drosophila Kc cells and is associated with snRNP proteins, suggesting that the U1b-contalning snRNP particles are able to participate in the process of premRNA splicing. We have also examined the expression throughout Drosophila development of the two U1 variants relative to the prototype sequence. The U1c variant is undetectable by our methods, while the U1b variant exhibits a primarily embryonic pattern reminiscent of the expression of certain U1 variants in sea urchin, Xenopus, and mouse.

Fast alignment of DNA and protein sequences - Landau,G. M; Vishkin, Uzi; Nussinov,R. (Methods in enzymology, 1990)

Interoperability of multiple autonomous databases - Litwin,Witold; Mark,Leo; Roussopoulos, Nick (ACM Computing SurveysACM Comput. Surv., 1990)

IPS-2: the second generation of a parallel program measurement system - Miller, B. P; Clark, M.; Hollingsworth, Jeffrey K; Kierstead, S.; Lim,S. -S; Torzewski, T. (IEEE Transactions on Parallel and Distributed Systems, 1990)
IPS, a performance measurement system for parallel and distributed programs, is currently running on its second implementation. IPS's model of parallel programs uses knowledge about the semantics of a program's structure to provide two important features. First, IPS provides a large amount of performance data about the execution of a parallel program, and this information is organized so that access to it is easy and intuitive. Secondly, IPS provides performance analysis techniques that help to guide the programmer automatically to the location of program bottlenecks. The first implementation of IPS was a testbed for the basic design concepts, providing experience with a hierarchical program and measurement model, interactive program analysis, and automatic guidance techniques. It was built on the Charlotte distributed operating system. The second implementation, IPS-2, extends the basic system with new instrumentation techniques, an interactive and graphical user interface, and new automatic guidance analysis techniques. This implementation runs on 4.3BSD UNIX systems, on the VAX, DECstation, Sun 4, and Sequent Symmetry multiprocessor
Keywords: 4.3BSD UNIX systems; automatic guidance techniques; Automatic testing; Charlotte distributed operating system; CPA; DECstation; design concepts; distributed programs; graphical user interface; Graphical user interfaces; Instruments; interactive program analysis; IPS-2; measurement; message systems; network operating systems; Operating systems; parallel program measurement system; parallel programming; parallel programs; Performance analysis; performance analysis techniques; performance evaluation; performance measurement system; Power system modeling; program bottlenecks; program diagnostics; Programming profession; semantics; Sequent Symmetry multiprocessor; shared-memory systems; software tools; Springs; Sun; Sun 4; Unix; VAX

Structure and expression of the Drosophila melanogaster gene for the U1 small nuclear ribonucleoprotein particle 70K protein. - Mancebo,R.; Lo,P. C.; Mount, Stephen M. (Molecular and Cellular BiologyMol. Cell. Biol., 1990)
A genomic clone encoding the Drosophila U1 small nuclear ribonucleoprotein particle 70K protein was isolated by hybridization with a human U1 small nuclear ribonucleoprotein particle 70K protein cDNA. Southern blot and in situ hybridizations showed that this U1 70K gene is unique in the Drosophila genome, residing at cytological position 27D1,2. Polyadenylated transcripts of 1.9 and 3.1 kilobases were observed. While the 1.9-kilobase mRNA is always more abundant, the ratio of these two transcripts is developmentally regulated. Analysis of cDNA and genomic sequences indicated that these two RNAs encode an identical protein with a predicted molecular weight of 52,879. Comparison of the U1 70K proteins predicted from Drosophila, human, and Xenopus cDNAs revealed 68% amino acid identity in the most amino-terminal 214 amino acids, which include a sequence motif common to many proteins which bind RNA. The carboxy-terminal half is less well conserved but is highly charged and contains distinctive arginine-rich regions in all three species. These arginine-rich regions contain stretches of arginine-serine dipeptides like those found in transformer, transformer-2, and suppressor-of-white-apricot proteins, all of which have been identified as regulators of mRNA splicing in Drosophila melanogaster.

Dynamic bin packing problem - Dikshit,Piyush; Guimaraes,Katia; Ramamurthy,Maya; Agrawala, Ashok K.; Larsen,Ronald L (SIAM Journal on Computing, 1989)
In a previous work we have defined a general architecture model for autonomous systems, which can be mapped easily to describe the functions of any automated system (SDAG-86-01). In this note, we use the model to describe the problem of thermal management in space stations. First we briefly review the architecture, then we present the environment of our application, and finally we detail the specific function for each functional block of the architecture for that environment.

Fast parallel and serial approximate string matching* 1 - Landau,G. M; Vishkin, Uzi (Journal of Algorithms, 1989)

Functional and psychosocial effects of multimodality limb-sparing therapy in patients with soft tissue sarcomas - Chang,A. E; Steinberg,S. M; Culnane,M.; Lampert,M. H; Reggia, James A.; Simpson,C. G; Hicks,J. E; White,D. E; Yang,J. J; Glatstein,E. (Journal of Clinical Oncology, 1989)

Gabriel: A design environment for DSP - Lee,E. A; Ho,W. H; Goei,E. E; Bier,J. C; Bhattacharyya, Shuvra S. (Acoustics, Speech and Signal Processing, IEEE Transactions on, 1989)

Fast string matching with k differences. - Landau,G. M; Vishkin, Uzi (J. COMP. SYST. SCI., 1988)

Fast string matching with k differences* 1,* 2 - Landau,G. M; Vishkin, Uzi (Journal of Computer and System Sciences, 1988)

Locating alignments with k differences for nucleotide and amino acid sequences - Landau,G. M; Vishkin, Uzi; Nussinov,R. (Computer applications in the biosciences: CABIOS, 1988)

Parallel construction of a suffix tree with applications - Apostolico,A.; Iliopoulos,C.; Landau,G. M; Schieber,B.; Vishkin, Uzi (Algorithmica, 1988)

An efficient string matching algorithm with K substitutions for nucleotide and amino acid sequences* - Landau,G. M; Vishkin, Uzi; Nussinov,R. (Journal of theoretical biology, 1987)

An evaluation of jump-ahead techniques in menu selection - Laverson,Alan; Norman,Kent; Shneiderman, Ben (Behaviour & Information Technology, 1987)
Menu selection systems provide a means of selecting operations and retrieving information which requires little training and reduces the need for memorizing complex command sequences. However, a major disadvantage of many menu selection systems is that experienced users cannot traverse the menu tree significantly faster than novices. A common solution to this problem is to provide the menu selection system with a jump-ahead capability.The purpose of this research was to evaluate two jump-ahead methods (type-ahead and direct-access). In the type-ahead method the user anticipates a selection on each of several successive menus and enters as many selections at one time as desired. In the direct-access method, each menu frame is assigned a unique name which the user must enter to locate it. Thirty-two students were given training on an information retrieval system for college course information and were required to learn the two jump-ahead methods in a counterbalanced design. The direct-access method resulted in fewer traversals to learn the system, lower error rates, and reduced learning time. The subjective impressions, obtained from post-experiment questionnaires and oral comments, indicated that the direct-access jump-ahead method was also preferred in a frequently used menu selection system.

Parallel construction of a suffix tree - Landau,G.; Schieber,B.; Vishkin, Uzi (Automata, Languages and Programming, 1987)

Window control strategies for on-line text traversal - Lifshitz,K.; Shneiderman, Ben (Department of Computer Science and Human Computer Interaction Laboratory, University of Maryland, College Park, MD (correspondence with B. Schneiderman), 1987)
Larger and higher resolution screens that support multiple windows are now widely available. They are often used to traverse hypertext databases for fact retrieval, education or casual browsing. This paper introduces window control strategies that we implemented, describes their cognitive complexity, and characterizes the tasks that users might encounter. An infomal usage by dozens of visitors and a usability test with four subjects performing information search tasks revealed the limitations of several strategies and guided us to select user control of article placement in a tiled non-overlapping multiple window display.

Efficient Parallel and Serial String Matching - Landau,G. M; Vishkin, Uzi (Computer Science Department Technical Report, 1986)

An efficient string matching algorithm with k differences for nudeotide and amino acid sequences - Landau,G. M; Vishkin, Uzi; Nussinov,R. (Nucleic acids research, 1986)

Efficient string matching with k mismatches - Landau,G. M; Vishkin, Uzi (Theoretical Computer Science, 1986)

Introducing efficient parallelism into approximate string matching and a new serial algorithm - Landau,G. M; Vishkin, Uzi (Proceedings of the eighteenth annual ACM symposium on Theory of computing, 1986)

A Special-Function Unit for Sorting and Sort-Based Database Operations - Raschid, Louiqa; Fei,T.; Lam,H.; Su,S. Y.W (IEEE Transactions on Computers, 1986)
Achieving efficiency in database management functions is a fundamental problem underlying many computer applications. Efficiency is difficult to achieve using the traditional general-purpose von Neumann processors. Recent advances in microelectronic technologies have prompted many new research activities in the design, implementation, and application of database machines which are tailored for processing database management functions. To build an efficient system, the software algorithms designed for this type of system need to be tailored to take advantage of the hardware characteristics of these machines. Furthermore, special hardware units should be used, if they are cost- effective, to execute or to assist the execution of these software algorithms.
Keywords: Application software; Computer applications; Database machines; Hardware; hardware sorter; Microelectronics; Software algorithms; Software design; Software systems; sort-based algorithms for database operations; sorting; special-function processor; Technology management

Direct spatial search on pictorial databases using packed R-trees - Roussopoulos, Nick; Leifker,D. (ACM SIGMOD Record, 1985)

Efficient string matching in the presence of errors - Landau,G. M; Vishkin, Uzi (Foundations of Computer Science, 1985., 26th Annual Symposium on, 1985)

An experimental comparison of tabular and graphic data presentation - Powers,Matthew; Lashley,Conda; Sanchez,Pamela; Shneiderman, Ben (International Journal of Man-Machine Studies, 1984)
We present the results of our experiment designed to test the hypothesis that more usable information can be conveyed using a combination of graphical and tabular data then by using either form alone. Our independent variables were memory (recall and non-recall) and form (tables, graphs, or both). Comprehension was measured with a multiple choice exam consisting of three types of questions (retrieve, compare, or compare/calculate answers). Both non-recall and tabular treatments significantly increased comprehension. Combinations of graphs and tables produced slower but more accurate performance. An executive should use the form with which he/she is most familiar and comfortable.

An introduction to PSQL: A pictorial structured query language - Roussopoulos, Nick; Leifker,D. (Proc. IEEE Workshop on Visual Languages, 1984)

Small Ribonucleoproteins from Eukaryotes: Structures and Roles in RNA Biogenesis - Steitz,J. A.; Wolin,S. L.; Rinke,J.; Pettersson,I.; Mount, Stephen M.; Lerner,E. A.; Hinterberger,M.; Gottlieb,E. (Cold Spring Harbor Symposia on Quantitative BiologyCold Spring Harb Symp Quant Biol, 1983)
Detailed reviews describing work presented at the annual Cold Spring Harbor Symposia on Quantitative Biology

Structure and function of small ribonucleoproteins from eukaryotic cells - Steitz,J. A.; Berg,C; Gottlieb,E.; Hardin,J A; Hashimoto,C; Hendrick,J P; Hinterberger,M.; Krikeles,M; Lerner,M R; Mount, Stephen M. (Princess Takamatsu symposiaInt. Symp. Princess Takamatsu Cancer Res. Fund, 1982)
Autoantibodies from patients with systemic lupus erythematosus and other related diseases have been used to identify and study small RNA-protein complexes from mammalian cells. Properties of three previously described and several new classes of small ribonucleoproteins (RNPs) are reviewed. The sequence of Drosophila U1 RNA reveals that the region proposed to pair with 5' splice junctions is conserved, while that proposed to interact with 3' junctions diverges; this forces some revision of the model for U1 small nuclear (sn)RNP participation in hnRNA splicing. Further characterization of the Ro and La small RNPs has shown that the Ro small cytoplasmic (sc)RNPs are a subclass of La RNPs. Both tRNA and 5S rRNA precursors are at least transiently associated with the La protein. This raises the possibility that the La protein may be an RNA polymerase III transcription factor.
Keywords: Antigen-Antibody Complex; Autoantibodies; HUMANS; Lupus Erythematosus, Systemic; Nucleoproteins; Ribonucleoproteins; RNA Polymerase III; Transcription, Genetic

Implementation of language enhancements - Zelkowitz, Marvin V; Lyle,James R. (Computer Languages, 1981)
Data abstractions have been proposed as a means to enhance program modularity. The implementation of such new features to an existing language is typically handled by either rewriting large portions of an existing compiler or by using a preprocessor to translate the extensions into the standard language. The first technique is expensive to implement while the latter is usually slow and clumsy to use. In this paper a data abstraction addition to PL 1 is described and a hybrid implementation is given. A minimal set of primitive features are added to the compiler and the other extensions are added via an internal macro processor that expands the new syntax into the existing language.
Keywords: Compiler design; Data abstraction; Language extensions; specifications

Are snRNPs involved in splicing? - Lerner,Michael R.; Boyle,John A.; Mount, Stephen M.; Wolin,Sandra L.; Steitz,Joan A. (Nature, 1980)
Discrete, stable small RNA molecules are found in the nuclei of cells from a wide variety of eukaryotic organisms. Many of these small nuclear RNA (snRNA) species, which range in size from about 90 to 220 nucleotides, have been well-characterised biochemically, and some sequenced. However, their function has remained obscure. The most abundant snRNA species exist as a closely related set of RNA–protein complexes called small nuclear ribonucleoproteins (snRNPs). snRNPs are the antigens recognised by antibodies from some patients with lupus erythematosus (LE), an autoimmune rheumatic disease. Anti-RNP antibodies from lupus sera selectively precipitate snRNP species containing Ula7 and Ulb9 RNAs from mouse Ehrlich ascites cell nuclei, whereas anti-Sm antibodies bind these snRNPs and four others containing U2, U4, US and U6 RNAs. Both antibody systems precipitate the same seven prominent nuclear proteins (molecular weight 12,000–32,000). All molecules of the snRNAs U1, U2, U4, U5 and U6 appear to exist in the form of antigenic snRNPs9. The particles sediment at about 10S and each probably contains a single snRNA molecule. Indirect immunofluorescence studies using anti-RNP and anti-Sm sera confirm the nuclear (but non-nucleolar) location of the antigenic snRNPs. Here we present several lines of evidence that suggest a direct involvement of snRNPs in the splicing of hnRNA. Most intriguing is the observation that the nucleotide sequence at the 5′ end of U1 RNA exhibits extensive complementarity to those across splice junctions in hnRNA molecules.

Implementation of a Capability-Based Data Abstraction - Zelkowitz, Marvin V; Larsen,H.J. (Software Engineering, IEEE Transactions on, 1978)
One important feature in programming language design is an appropriate data definitional facility. Criteria now recognized as important are the concepts of information hiding and data abstraction. The problem, however, is to embed these ideas into languages. Although including these ideas has often led to the design of a new language, that is not always necessary. Such facilities may be added to languages like PL/1 or Pascal. This report discusses the inclusion of such facilities within one such PL/1 compiler. While the resulting system does not have the optimal set of protection features, it does have several advantages: the base language is known to a large class of programmers, there are many such compilers already written, and the system achieves almost as much protection as is needed.
Keywords: Data abstraction; Pascal; PL/1; infonnation hiding; pointer variables

Personality and programming: Time-sharing vs. batch preference - Lee,Jeanne M.; Shneiderman, Ben (Proceedings of the 1978 annual conference - Volume 2, 1978)
Only within the past ten years has some attention been given to psychological concerns of human-machine interface. A review of the literature in this area reveals that personality has received the least attention, but interest is growing. If critical personality factors can be isolated and associated with particular programming tasks, such information could be a useful tool for education as well as management. The hypothesis of this exploratory study was that two personality dimensions, assertiveness and locus of control, influence a programmer's choice of batch or interactive processing for program development. Locus of control relates to the perception an individual has of his/her influence over events. Assertiveness allows an individual expression in a manner that fully communicates personal desires without infringing upon the rights of others. These two dimensions and the programmer's preference for batch or interactive mode were studied through a questionnaire survey of experienced programmers.
Keywords: Assertive/passive; batch processing; Locus of control; Personality; Programming; Psychology; Time sharing

Error checking with pointer variables - Zelkowitz, Marvin V; McMullin,Paul R.; Merkel,Keith R.; Larsen,Howard J. (Proceedings of the 1976 annual conference, 1976)
The use of pointer variables in a programming language often results in a difficult class of errors to detect. Pointers may point to storage that no longer is allocated, or storage may be allocated as one data type and accessed as another. This report describes the implementation of pointers in the PLUM PL/1 compiler such that all error conditions are detected. In addition, preliminary tests with PLUM seem to indicate that the total checking of pointers is not as expensive an operation as it first appears.