Major Requirement (major + requirement)

Distribution by Scientific Domains


Selected Abstracts


Managing Transportation Infrastructure for Sustainable Development

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2002
Edward O. Akinyemi
Major requirements for operationalization of the concept of sustainable development in urban transportation infrastructure operations management are presented. In addition, it is shown that the current approach to management is incompatible with the requirements for sustainable urban development. Consequently, the conceptual framework of a desirable approach is proposed. The philosophy of this approach is that the basic mission of infrastructure operations management is to obtain and maintain the maximum levels of people and goods mobility possible within the resources and environmental capacities in an area. A mathematical model is presented for obtaining the desirable levels and characteristics of traffic on each segment of an urban transportation network. In addition, three illustrative applications of the implemented model are presented. [source]


Parallel tiled QR factorization for multicore architectures

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13 2008
Alfredo Buttari
Abstract As multicore systems continue to gain ground in the high-performance computing world, linear algebra algorithms have to be reformulated or new algorithms have to be developed in order to take advantage of the architectural features on these new processors. Fine-grain parallelism becomes a major requirement and introduces the necessity of loose synchronization in the parallel execution of an operation. This paper presents an algorithm for the QR factorization where the operations can be represented as a sequence of small tasks that operate on square blocks of data (referred to as ,tiles'). These tasks can be dynamically scheduled for execution based on the dependencies among them and on the availability of computational resources. This may result in an out-of-order execution of the tasks that will completely hide the presence of intrinsically sequential tasks in the factorization. Performance comparisons are presented with the LAPACK algorithm for QR factorization where parallelism can be exploited only at the level of the BLAS operations and with vendor implementations. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Checkpointing BSP parallel applications on the InteGrade Grid middleware

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 6 2006
Raphael Y. de Camargo
Abstract InteGrade is a Grid middleware infrastructure that enables the use of idle computing power from user workstations. One of its goals is to support the execution of long-running parallel applications that present a considerable amount of communication among application nodes. However, in an environment composed of shared user workstations spread across many different LANs, machines may fail, become inaccessible, or may switch from idle to busy very rapidly, compromising the execution of the parallel application in some of its nodes. Thus, to provide some mechanism for fault tolerance becomes a major requirement for such a system. In this paper, we describe the support for checkpoint-based rollback recovery of Bulk Synchronous Parallel applications running over the InteGrade middleware. This mechanism consists of periodically saving application state to permit the application to restart its execution from an intermediate execution point in case of failure. A precompiler automatically instruments the source code of a C/C++ application, adding code for saving and recovering application state. A failure detector monitors the application execution. In case of failure, the application is restarted from the last saved global checkpoint. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Efficient mucosal delivery of the HIV-1 Tat protein using the synthetic lipopeptide MALP-2 as adjuvant

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2003
Stefan Borsutzky
Abstract A major requirement for HIV/AIDS research is the development of a mucosal vaccine that stimulates humoral and cell-mediated immune responses at systemic and mucosal levels, thereby blocking virus replication at the entry port. Thus, a vaccine prototype based on biologically active HIV-1 Tat protein as antigen and the synthetic lipopeptide, macrophage-activating lipopeptide-2 (MALP-2), asa mucosal adjuvant was developed. Intranasal administration to mice stimulated systemic and mucosal anti-Tat antibody responses, and Tat-specific T cell responses, that were more efficient than those observed after i.p. immunization with Tat plus incomplete Freund's adjuvant. Major linear B cell epitopes mapped within aa 1,20 and 46,60, whereas T cell epitopes were identified within aa 36,50 and 56,70. These epitopes have also been described in vaccinated primates and in HIV-1-infected individuals with better prognosis. Analysis of the anti-Tat IgG isotypes in serum, and the cytokine profile of spleen cells indicated that a dominant Th1 helper response was stimulated by Tat plus MALP-2, as opposed to the Th2 response observed with Tat plus incomplete Freund's adjuvant. Tat-specific IFN-,-producing cells were significantly increased only in response to Tat plus MALP-2. These data suggest that Malp-2 may represent an optimal mucosal adjuvant for candidate HIV vaccines based on Tat alone or in combination with other HIV antigens. [source]


Rasagiline: defining the role of a novel therapy in the treatment of Parkinson's disease

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2006
F. Stocchi
Summary Parkinson's disease (PD) is a therapy area with considerable unmet needs. The current key targets for PD treatment include the slowing of disease progression, improved control of motor fluctuations in advanced disease and the treatment of nonmotor symptoms. In view of such major requirements, it is important to consider how new drug treatments fit into the context of PD therapy, and the practical advantages that they may offer in the management of PD in clinical practice. Rasagiline is a novel, second-generation, irreversible, selective monoamine oxidase type B inhibitor that is indicated for the treatment of idiopathic PD, either as initial monotherapy or as adjunct therapy (with levodopa) for patients experiencing end-of-dose motor fluctuations. This review assesses the outcome from several large-scale clinical studies that have investigated the use of rasagiline in early and advanced PD patient populations and discusses the role of rasagiline within the current scope of PD therapy. [source]