hold. If such matrix X exists, then it is unique, denoted by A, and called the group inverse of A. It is well known that the group inverse of a square matrix A exists if and only if rank(A) = rank(A) (see, for example, [1, Section 4.4] for details). Clearly, not every matrix is group invertible. It is straightforward to prove that A is group invertible if and only if A is group invertible, and ...

BACKGROUND Non-invasive detection of vascular dysfunction in the early stage is clinically important in patients with sleep apnea syndrome (SAS). Flow-mediated dilatation (FMD) is a novel clinical marker of endothelial function. However, it is not clear whether this is useful in the SAS patient. METHODS Echocardiographic parameters and FMD were measured in 129 patients with SAS. Apnea-hypopne...

Centrosomes consist of a centriole pair surrounded by pericentriolar material (PCM). Previous work suggested that centrioles are required to organize PCM to form a structurally stable organelle. Here, we characterize SAS-4, a centriole component in Caenorhabditis elegans. Like tubulin, SAS-4 is incorporated into centrioles during their duplication and remains stably associated thereafter. In th...

Version 8 of the SAS® System brings powerful new features for managing a Hybrid OLAP (HOLAP) or Distributed Multidimensional Data environment. The HOLAP component of the SAS/MDDB® Server software enables you to include SAS Multidimensional databases (MDDB), SAS files, and relational (RDBMS) databases into a single, powerful OLAP reporting environment. Support for HOLAP data groups is fully inte...

Previous efforts to characterize conservation between the human and mouse genomes focused largely on sequence comparisons. These studies are inherently limited because they don't account for gene structure differences, which may exist despite genomic sequence conservation. Recent high-throughput transcriptome studies have revealed widespread and extensive overlaps between genes, and transcripts...

The sequence of echoes detected by an active Synthetic Aperture Sonar (SAS) is coherently added in an appropriate way to produce an image with greatly enhanced resolution in the azimuth, or along-track direction when compared with an image obtained from a standard Side Looking Sonar (SLS). The SAS processing originates from the Synthetic Aperture Radar (SAR) concept. A complete introduction to ...

SAS metadata is the data about SAS datasets, which is critical to the effective manipulation and analysis of SAS data. The SAS metadata exploration traditionally proceeds as ad-hoc programming on SAS Dictionary tables, which is inadequate, inefficient, and sometime complicated. Based on SAS ODBC functionality and hypertext techniques, a documentation generator called Datamapper is being develop...

SAS has a robust set of tools that provide business analysts many capabilities ranging from statistics and data mining to data integration and business intelligence. In the early years, prior to version 9, typical analysts would simply use the SAS programming language and write code to obtain the desired results. Support had two aspects: one from the systems administration team where the SAS so...

The SAS administrator exists in all types of organizations: small, medium, large, etc. This paper focuses on medium-to-large scale SAS ® System implementations. The SAS Administrator is not a position as much as it is a role. It can be a single individual or a team comprised of SAS-trained personnel, along with other IT staff within a company. While this role is very important, it is often not ...