34 research outputs found
Multiple Query Optimization For Data Analysis Applications on Clusters of SMPs
This paper is concerned with the efficient execution of multiple query
workloads on a cluster of SMPs. We target applications that access and
manipulate large scientific datasets. Queries in these applications involve
user-defined processing operations on data and distributed data structures
to hold intermediate and final results. Our goal is to implement system
components to leverage previously computed query results and to effectively
utilize processing power and aggregated I/O bandwidth on SMP nodes so that
both single queries and multi-query batches can be efficiently executed.
(Also referenced as UMIACS-TR-2001-78
Secreção de aldosterona em pacientes com choque séptico : estudo prospectivo
Objective: To assess serum levels of the main factors that regulate the activation of the zona glomerulosa and aldosterone production in patients with septic shock, as well as their response to a high-dose (250 μg) adrenocorticotropic hormone (ACTH) stimulation test. Subjects and methods: In 27 patients with septic shock, baseline levels of aldosterone, cortisol, ACTH, renin, sodium, potassium, and lactate were measured, followed by a cortrosyn test. Results: Renin correlated with baseline aldosterone and its variation after cortrosyn stimulation. Baseline cortisol and its variation did not correlate with ACTH. Only three patients had concomitant dysfunction of aldosterone and cortisol secretion. Conclusions: Activation of the zona glomerulosa and zona fasciculata are independent. Aldosterone secretion is dependent on the integrity of the renin-angiotensin-aldosterone system, whereas cortisol secretion does not appear to depend predominantly on the hypothalamic-pituitaryadrenal axis. These results suggest that activation of the adrenal gland in critically ill patients occurs by multiple mechanisms.Objetivo: Avaliar os nÃveis séricos dos principais fatores que regulam a ativação da zona glomerulosa e a produção de aldosterona em pacientes com choque séptico, assim como sua resposta ao teste de cortrosina em alta dose (250 μg). Sujeitos e métodos: Em 27 portadores de choque séptico, foram aferidos nÃveis basais de aldosterona, cortisol, ACTH, renina, sódio, potássio e lactato, bem como realizado teste de cortrosina. Resultados: Renina se correlacionou com nÃveis basais de aldosterona e sua variação após teste de cortrosina. Cortisol basal e sua variação não se correlacionaram com ACTH. Apenas três pacientes apresentaram disfunção concomitante da secreção de aldosterona e cortisol. Conclusões: Ativação das zonas fasciculada e glomerulosa são independentes. Secreção de aldosterona é dependente da integridade do sistema renina-angiotensina-aldosterona, enquanto secreção de cortisol não parece predominantemente dependente do eixo hipotálamo-hipófise-adrenal. Esses resultados sugerem que a ativação da adrenal em pacientes crÃticos ocorre por múltiplos mecanismos
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
Active Proxy-G: Optimizing the Query Execution Process in the Grid
The Grid environment facilitates collaborative work and allows many users to query and process data over geographically dispersed data repositories. Over the past several years, there has been a growing interest in developing applications that interactively analyze datasets, potentially in a collaborative setting. We describe an Active Proxy-G service that is able to cache query results, use those results for answering new incoming queries, generate subqueries for the parts of a query that cannot be produced from the cache, and submit the subqueries for final processing at application servers that store the raw datasets. We present an experimental evaluation to illustrate the effects of various design tradeoJj5 . We also show the benefits that two real applications gain from using the middleware
Exploiting Functional Decomposition for Efficient Parallel Processing of Multiple Data Analysis Queries
Reuse is a powerful method for improving system performance. In this paper, we examine functional decomposition for improving data reuse, and therefore overall query execution performance, in the context of data analysis applications. Additionally, we look at the performance effects of using various projection primitives that make it possible to transform intermediate results generated during the execution of a previous query so that they can be reused by a new query. A satellite data analysis application is used to experimentally show the performance benefits achieved using the techniques presented in the paper
Decision Tree Construction for Data Mining on Cluster of Shared-Memory Multiprocessors
Classification of very large datasets is a challenging problem in data
mining. It is desirable to have decision-tree classifiers that can
handle large datasets, because a large dataset often increases the
accuracy of the resulting classification model. Classification tree
algorithms can benefit from parallelization because of large memory
and computation requirements for handling large datasets. Clusters of
shared-memory multiprocessors (SMPs), in which each shared-memory node
has a small number of processors (e.g., 2--8 processors) and is
connected to the other nodes via a high-speed inter-connect, have
become a popular alternative to pure distributed-memory and
shared-memory machines. A cluster of SMPs provides a two-tier
architecture, in which a combination of shared-memory and
distributed-memory paradigms can be employed. In this paper we
investigate decision tree construction on a cluster of SMPs. We
present an algorithm that employs a hybrid approach. The
classification training dataset is partitioned across the SMP nodes so
that each SMP node performs tree construction using a subset of the
records in the dataset. Within each SMP node, on the other hand, tasks
associated with an attribute are dynamically scheduled to the
light-weight threads running on the SMP node. We present experimental
results on a Linux PC cluster with dual-processor SMP nodes.
(Also cross-referenced as UMIACS-TR-2000-78