Multithreaded languages for scientific and technical computing

An overview of language support for parallel technical computing is provided. The rationale for multithreaded languages, in which the programmer explicitly specifies what work is to be carried out by multiple processors and how their activities should be coordinated, is described. The discussion begins with an introduction to the general models for manipulating multiple threads and how they are incorporated into programming languages. The wide variety of features for creating multiple threads, scheduling their execution, synchronizing their activities, and sharing data among them are then examined. Examples in a simplified, FORTRAN-like notation are included. It is shown how the language features are distributed among commercial compiler implementations. Some less traditional approaches to multithreaded language support are presented to provide a glimpse at what might be expected in future languages and compilers     

The Emerging Faculty as Team

The Computer Science Department at Oregon State University is re-examining faculty roles and the relationships between individual faculty members and the department and university. The result is a system for deciding upon faculty activities that makes more effective use of individual faculty members' talents and interests. The scheme aims to help faculty members enhance their own performance and progress in their careers while the overall performance of the department is increased. The primary features of the system are a revision and re-allocation of long-term individual responsibilities and a task-oriented approach to schedule short-term faculty activities. While the plan was implemented only recently, preliminary results are encouraging.     

Do parallel languages respond to the needs of scientificprogrammers?

Parallel programming is considered from the viewpoint of scientific researchers, with particular reference to their requirements for language support. The questions of how scientists go about developing parallel applications, what role language plays in determining the success of their programming efforts, how much scientific programmers should be expected to know about parallel languages and machines and what computer scientists can do to facilitate parallel scientific programming are addressed. The discussion centers on the `mainline' supercomputers for scientific and engineering applications: vector and scalar MIMD (multiple instruction, multiple data) multiprocessors. New research efforts that are tackling the problems facing scientific programmers are discussed     

Reexamination of human T cell lymphotropic virus (HTLV-I/II) prevalence

In the United States, blood donors are being screened for infection with human T cell lymphotropic viruses I and II (HTLV-I/II) by serologic means, which detect antibodies to the structural proteins of these viruses. Because patients with mycosis fungoides (MF) usually do not have such antibodies even though their cells harbor HTLV-I Tax and/or pol proviral sequences, it was questioned whether the prevalence of HTLV infection among healthy blood donors may also be underestimated by current means of testing. To examine this possibility, a study on specimens of relatives of mycosis fungoides patients (MFR) was begun. In addition, to collect data more expeditiously, a cohort of former injection drug users (IDUs) was tested by routine serologic methods, as well as by PCR/Southern blot analysis for Tax, pol, and gag proviral sequences and Western blot analysis for antibodies to the Tax gene product. To date, 6/8 MFRs and 42/81 (51.8%) of HIV-negative IDUs proved to be positive for HTLV, whereas routine serology identified none of the MFR and only 18/81 (22.2%) of the IDUs. Among the latter test subjects, the incidence of HTLV-I also proved to be 10 times higher than expected. Therefore, it is likely that among healthy blood donors infection with HTLV-I/II is more prevalent than is currently assumed. Since Tax is the transforming sequence of HTLV-I/II, testing for Tax sequences and antibodies to its gene product may be desirable in blood transfusion and tissue donor facilities.     

Challenges in location-aware computing

The availability of massive amounts of high-quality data as well as advances in computing and communications suggest the possibility of powerful new applications in science, commerce, environment, and government-but many research challenges remain. Research in geospatial information systems is inherently multidisciplinary, and research efforts are likely to be most successful if conducted by teams that combine expertise in applications as well as information technology. Advances in location-aware computing, in particular, could have important implications not just for how geospatial data are acquired but also for how and with what quality they can be delivered and how mobile and geographically distributed systems are designed.     

Cutaneous disease resembling mycosis fungoides in HIV-infected patients whose skin and blood cells also harbor proviral HTLV type I

Two homosexual HIV-infected patients with lymphocyte counts of < 50 presented with intense pruritus, hyperpigmentation, and skin lesions clinically suggestive of the cutaneous T cell lymphoma, mycosis fungoides. On light microscopy, the skin biopsies were difficult to interpret because of the sparseness of the lymphocytic infiltrates. However, electron microscopy revealed typical Sézary cells in the peripheral blood and skin. Cultures of blood mononuclear cells of one of the patients generated HTLV-I-like particles. Although both patients lacked antibodies to HTLV, their blood and skin specimens proved to harbor tax and pol HTLV-I proviral sequences as shown by the polymerase chain reaction and Southern blot analysis. Dual infection with HIV and HTLV should be considered in the diagnostic work-up of patients at risk, even in the absence of demonstrable antibodies. Dual infections could result in clinical manifestations and evolution of disease not anticipated in patients who harbor only one of these retroviruses.