John Saldanha

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The recent proliferation of portable computers, the advent of personal digital assistants (PDAs) and continuing advances in computer networking all point to a future in which mobility of both users and computing system elements will be standard. However, these developments also invalidate many of the assumptions made by current system software, which has(More)
West Nile Virus (WNV) collected from 179 human blood donors in 25 US states and three Canadian provinces during the 2003 and 2004 epidemic seasons were genetically analyzed. The evolution of WNV during its Western spread was examined by envelope (E) gene sequencing of all 179 cases and full open reading frame sequencing of a subset of 20 WNV to determine if(More)
BACKGROUND Transfusion-transmitted West Nile virus (WNV) infections were first reported in 2002, which led to rapid development of investigational nucleic acid amplification tests (NAT). A study was conducted to evaluate sensitivities of WNV screening and supplemental NAT assays first employed in 2003. STUDY DESIGN AND METHODS Twenty-five member-coded(More)
Existing distributed file systems are based on either a client-server model or a peer-to-peer model. We believe that the dynamic conditions of mobile computing and new classes of devices such as PDAs will no longer permit rigid adherence to either of these models. In this paper, we argue that a hybrid of the two will have to be used. We then propose a file(More)
BACKGROUND There have been no comparisons of the relative sensitivity of the two Food and Drug Administration-licensed multiplex (MPX) nucleic acid test (NAT) systems (Procleix Ultrio [Gen-Probe], TIGRIS platform [Novartis]; and cobas TaqScreen MPX [Roche Molecular Systems], cobas s 201 platform [Roche Instrument Center]) for detecting hepatitis B virus(More)
BACKGROUND A nucleic acid test (NAT) assay reference reagent for West Nile virus (WNV) RNA, consisting of heat-inactivated WNV grown in tissue culture and diluted in pooled, negative human plasma, was evaluated and quantitated in a collaborative study in which 14 laboratories participated. STUDY DESIGN AND METHODS Participants were requested to assay(More)
BACKGROUND Blood donation screening for West Nile virus (WNV) RNA by nucleic acid testing (NAT) was implemented in Canada in July 2003, and 14 WNV RNA-positive donations were identified. Samples were screened in minipools of six donations with a WNV assay (TaqScreen, Roche). Two of the donors were identified by single-donor screening that was initiated in(More)
The complexity of Nucleic acid Amplification Technology (NAT(1)), comprising sample preparation, amplification and detection methods, requires specific design considerations for both the laboratory and the procedures utilized in such testing. The purpose of this paper is to establish technical considerations for the performance of NAT. These include the(More)
BACKGROUND The cobas TaqScreen West Nile virus (WNV) test (Roche Molecular Systems) was licensed by the Food and Drug Administration (FDA) in August 2007 for detecting WNV RNA in pools of six or in individual donations (IDs). A series of studies established the performance characteristics of the assay and test system before FDA licensure. STUDY DESIGN AND(More)
BACKGROUND Three European laboratories evaluated the TaqScreen DPX test (DPX test), a multiplex nucleic acid test assay for the simultaneous detection and quantitation of parvovirus B19 (B19V) DNA and the detection of hepatitis A virus (HAV) RNA. STUDY DESIGN AND METHODS The 95% limit of detection of the test for B19V and HAV was determined using the(More)