Design of dynamic load-balancing tools for parallel applications

The design of general-purpose dynamic load-balancing tools for parallel applications is more challenging than the design of static partitioning tools. Both algorithmic and software engineering issues arise. The authors have addressed many of these issues in the design of the Zoltan dynamic load-balancing library. Zoltan has an object-oriented interface that makes it easy to use and provides separation between the application and the load-balancing algorithms. It contains a suite of dynamic load-balancing algorithms, including both geometric and graph-based algorithms. Its design makes it valuable both as a partitioning tool for a variety of applications and as a research test-bed for new algorithmic development. In this paper, the authors describe Zoltan's design and demonstrate its use in an unstructured-mesh finite element application

A General Graph Model For Representing Exact Communication Volume in Parallel Sparse Matrix–Vector Multiplication

In this paper, we present a new graph model of sparse matrix decomposition for parallel sparse matrix–vector multiplication. Our model differs from previous graph-based approaches in two main respects. Firstly, our model is based on edge colouring rather than vertex partitioning. Secondly, our model is able to correctly quantify and minimise the total communication volume of the parallel sparse matrix– vector multiplication while maintaining the computational load balance across the processors. We show that our graph edge colouring model is equivalent to the fine-grained hypergraph partitioning-based sparse matrix decomposition model. We conjecture that the existence of such a graph model should lead to faster serial and parallel sparse matrix decomposition heuristics and associated tools

Mechanisms of heterosubtypic immunity to lethal influenza A virus infection in fully immunocompetent, T cell-depleted, beta2-microglobulin-deficient, and J chain-deficient mice

Immunity that is cross-protective between different influenza A virus subtypes (termed heterosubtypic immunity) can be demonstrated readily in some animals but only rarely in humans. Induction of heterosubtypic immunity in humans by vaccines would provide public health benefit, perhaps offering some protection against pandemics or other new influenza A strains. Therefore, we studied mechanisms mediating heterosubtypic immunity in mice. Immunization with either A/H1N1 or A/H3N2 virus protected mice against mortality following heterosubtypic challenge while providing modest reductions in lung virus titers. No cross-protection was seen with distantly related type B influenza virus. Depletion of CD4+ or CD8+ T cells or both around the time of challenge had no significant effect on survival, indicating that these cells are not required at the effector stage. beta2-microglobulin knockout mice could be protected readily against heterosubtypic challenge, confirming that class I-restricted T cells are not required. In beta2-microglobulin -/- mice, depletion of CD4+ T cells partially abrogated heterosubtypic immunity, showing that they play a role in these mice. Passive transfer of Abs to naive recipients protected against subsequent challenge with homologous but not heterosubtypic virus. Because a role for secretory Abs has been suggested, we studied dependence on the J chain, which is required for polymeric Ig receptor-mediated IgA transport. J chain knockout mice were readily protected by heterosubtypic immunity, indicating that polymeric Ig receptor-mediated transport is not required. Better understanding of heterosubtypic immunity should be valuable in analyzing new vaccines, including peptide and DNA vaccines, intended to induce broadly cross-reactive immunity

Toward scalable matrix multiply on multithreaded architectures

Abstract. We show empirically that some of the issues that affected the design of linear algebra libraries for distributed memory architectures will also likely affect such libraries for shared memory architectures with many simultaneous threads of execution, including SMP architectures and future multicore processors. The always-important matrix-matrix multiplication is used to demonstrate that a simple one-dimensional data partitioning is suboptimal in the context of dense linear algebra operations and hinders scalability. In addition we advocate the publishing of low-level interfaces to supporting operations, such as the copying of data to contiguous memory, so that library developers may further optimize parallel linear algebra implementations. Data collected on a 16 CPU Itanium2 server supports these observations.

Safety, tolerability, and pharmacodynamics of an anti-interleukin-1α/β dual variable domain immunoglobulin in patients with osteoarthritis of the knee: a randomized phase 1 study

To investigate the safety, tolerability, pharmacokinetics, and pharmacodynamics of ABT-981, a human dual variable domain immunoglobulin simultaneously targeting interleukin (IL)-1α and IL-1β, in patients with knee osteoarthritis (OA). This was a randomized, double-blind, placebo-controlled, single-center study of multiple subcutaneous (SC) injections of ABT-981 in patients with mild-to-moderate OA of the knee (NCT01668511). Three cohorts received ABT-981 (0.3, 1, or 3 mg/kg) or placebo every other week for a total of four SC injections, and one cohort received ABT-981 (3 mg/kg) or placebo every 4 weeks for a total of three SC injections. Assessment of safety and tolerability were the primary objectives. A panel of serum and urine biomarkers of inflammation and joint degradation were evaluated. A total of 36 patients were randomized (ABT-981, n = 28; placebo, n = 8); 31 (86%) completed the study. Adverse event (AE) rates were comparable between ABT-981 and placebo (54% vs 63%). The most common AE reported with ABT-981 vs placebo was injection site erythema (14% vs 0%). ABT-981 significantly reduced absolute neutrophil count and serum concentrations of IL-1α/IL-1β, high-sensitivity C-reactive protein, and matrix metalloproteinase (MMP)-derived type 1 collagen. Serum concentrations of MMP-derived type 3 collagen and MMP-degraded C-reactive protein demonstrated decreasing trends with ABT-981. Antidrug antibodies were found in 37% of patients but were not associated with the incidence or severity of AEs. ABT-981 was generally well tolerated in patients with knee OA and engaged relevant tissue targets, eliciting an anti-inflammatory response. Consequently, ABT-981 may provide clinical benefit to patients with inflammation-driven OA

Cyclospora cayetanensis in sputum and stool samples Cyclospora cayetanensis em amostra de escarro

We report the observation of acid-fast Cyclospora cayetanensis oocysts in a sputum sample. The patient, a 60 year-old, HIV negative man, was successfully treated for pulmonary tuberculosis during 1997. On February 1998, he was admitted to our center due to loss of weight, cough with purulent expectoration, dysphonia and a radiological picture of pulmonary fibrosis. Bacilloscopic study of sputum (negative for acid-fast bacilli) stained with Ziehl-Neelsen technique showed large (8-10 µm) spherical, acid-fast Cyclospora cayetanensis oocysts. No other pathogens were isolated on cultures from this sample or from laryngeal biopsy. Serial parasitologic studies showed C. cayetanensis and also eggs of Trichuris trichiura, Ascaris lumbricoides and Hymenolepis nana and of Entamoeba coli cysts. The patient lives in the outskirts of Buenos Aires in a brick-made house with potable water and works as builder of sewers. He travelled in several occasions to the rural area of province of Tucumán which has poor sanitary conditions. C. cayetanensis is an emergent agent of diarrhea and as far as we know this is the first time the parasite is observed in respiratory samples.<br>Comunicamos a observação de grandes oocistos (8-10 µm de diâmetro) esféricos, ácido-álcool-resistentes de Cyclospora cayetanensis em amostra de escarro corada com a técnica de Ziehl-Neelsen. Na amostra não foram observados nem cultivados outros agentes patogênicos. Trata-se de um paciente do sexo masculino, 60 anos de idade, HIV (-), tratado previamente para tuberculose pulmonar (1997). Em fevereiro de 1998 apresentou-se em nosso hospital com perda de peso, tosse com expectoração purulenta, disfonia e imagens radiológicas de fibrose pulmonar. As culturas das amostras de escarro e da biopsia de laringe foram negativas. O exame parasitológico seriado de fezes mostrou ovos de Ascaris lumbricoides, Hymenolepis nana e Trichuris trichiura e cistos de Entamoeba coli. O paciente mora nos arredores de Buenos Aires numa casa de alvenaria com água potável e é construtor de fossas (cloacas). Realizou varias viagens à zona rural da província de Tucumán. Cyclospora cayetanensis é um agente emergente de diarréia e esta é, até onde nós sabemos, a primeira observação de oocistos deste parasito em amostra de vias respiratórias

DC Programming Approaches for Distance Geometry Problems

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