Learning the structure and content of an electronic medical record system

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 104-107).by Jiri Schindler.M.Eng

Are There Regional Variations in the Diagnosis, Surveillance, and Control of Methicillin-Resistant Staphylococcus aureus?

Abstract Objective: To assess the way healthcare facilities (HCFs) diagnose, survey, and control methicillin-resistant Staphylococcus aureus (MRSA). Design: Questionnaire. Setting: Ninety HCFs in 30 countries. Results: Evaluation of susceptibility testing methods showed that 8 laboratories (9%) used oxacillin disks with antimicrobial content different from the one recommended, 12 (13%) did not determine MRSA susceptibility to vancomycin, and 4 (4.5%) reported instances of isolation of vancomycin-resistant S. aureus but neither confirmed this resistance nor alerted public health authorities. A MRSA control program was reported by 55 (61.1%) of the HCFs. The following isolation precautions were routinely used: hospitalization in a private room (34.4%), wearing of gloves (62.2%), wearing of gowns (44.4%), hand washing by healthcare workers (53.3%), use of an isolation sign on the patient's door (43%), or all four. When the characteristics of HCFs with low incidence rates (< 0.4 per 1,000 patient-days) were compared with those of HCFs with high incidence rates (P = 0.4 per 1,000 patient-days), having a higher mean number of beds per infection control nurse was the only factor significantly associated with HCFs with high incidence rates (834 vs 318 beds; P = .02). Conclusion: Our results emphasize the urgent need to strengthen the microbiologic and epidemiologic capacities of HCFs worldwide to prevent MRSA transmission and to prepare them to address the possible emergence of vancomycin-resistant S. aureu

Short-Term Effects of Carbon Monoxide on Mortality: An Analysis within the APHEA Project

Objectives: We investigated the short-term effects of carbon monoxide on total and cardiovascular mortality in 19 European cities participating in the APHEA-2 (Air Pollution and Health: A European Approach) project. Methods: We examined the association using hierarchical models implemented in two stages. In the first stage, data from each city were analyzed separately, whereas in the second stage the city-specific air pollution estimates were regressed on city-specific covariates to obtain overall estimates and to explore sources of possible heterogeneity. We evaluated the sensitivity of our results by applying different degrees of smoothing for seasonality control in the city-specific analysis. Results: We found significant associations of CO with total and cardiovascular mortality. A 1-mg/m$^3$ increase in the 2-day mean of CO levels was associated with a 1.20% [95% confidence interval (CI), 0.63–1.77%] increase in total deaths and a 1.25% (95% CI, 0.30–2.21%) increase in cardiovascular deaths. There was indication of confounding with black smoke and nitrogen dioxide, but the pollutant-adjusted effect of CO on mortality remained at least marginally statistically significant. The effect of CO on total and cardiovascular mortality was observed mainly in western and southern European cities and was larger when the standardized mortality rate was lower. Conclusions: The results of this large study are consistent with an independent effect of CO on mortality. The heterogeneity found in the effect estimates among cities may be explained partly by specific city characteristics

The Nucleoside Diphosphate Kinase Gene Nme3 Acts as Quantitative Trait Locus Promoting Non-Mendelian Inheritance

The t-haplotype, a variant form of the t-complex region on mouse chromosome 17, acts as selfish genetic element and is transmitted at high frequencies (>95%) from heterozygous (t/+) males to their offspring. This phenotype is termed transmission ratio distortion (TRD) and is caused by the interaction of the t-complex responder (Tcr) with several quantitative trait loci (QTL), the t-complex distorters (Tcd1 to Tcd4), all located within the t-haplotype region. Current data suggest that the distorters collectively impair motility of all sperm derived from t/+ males; t-sperm is rescued by the responder, whereas +-sperm remains partially dysfunctional. Recently we have identified two distorters as regulators of RHO small G proteins. Here we show that the nucleoside diphosphate kinase gene Nme3 acts as a QTL on TRD. Reduction of the Nme3 dosage by gene targeting of the wild-type allele enhanced the transmission rate of the t-haplotype and phenocopied distorter function. Genetic and biochemical analysis showed that the t-allele of Nme3 harbors a mutation (P89S) that compromises enzymatic activity of the protein and genetically acts as a hypomorph. Transgenic overexpression of the Nme3 t-allele reduced t-haplotype transmission, proving it to be a distorter. We propose that the NME3 protein interacts with RHO signaling cascades to impair sperm motility through hyperactivation of SMOK, the wild-type form of the responder. This deleterious effect of the distorters is counter-balanced by the responder, SMOKTcr, a dominant-negative protein kinase exclusively expressed in t-sperm, thus permitting selfish behaviour and preferential transmission of the t-haplotype. In addition, the previously reported association of NME family members with RHO signaling in somatic cell motility and metastasis, in conjunction with our data involving RHO signaling in sperm motility, suggests a functional conservation between mechanisms for motility control in somatic cells and spermatozoa

Matching application access patterns to storage device characteristics

Conventional computer systems have insufficient information about storage device performance characteristics. As a consequence, they utilize the available device resources inefficiently, which, in turn, results in poor application performance. This dissertation demonstrates that a few high-level, device-independent hints encapsulating unique storage device characteristics can achieve significant I/O performance gains without breaking the established abstraction of a storage device as a linear address space of fixed-size blocks. A piece of system software (here referred to as storage manager), which translates application requests into individual I/Os, can automatically match application access patterns to the provided characteristics. This results in more efficient utilization of storage devices and thus improved application performance. This dissertation (i) identifies specific features of disk drives, disk arrays, and MEMS-based storage devices not exploited by conventional systems, (ii) quantifies the potential performance gains these features offer, and (iii) demonstrates on thre

Matching Application Access Patterns to Storage Device Characteristics (CMU-PDL-03-109)

Conventional computer systems have insufficient information about storage device performance characteristics. As a consequence, they utilize the available device resources inefficiently, which, in turn, results in poor application performance. This dissertation demonstrates that a few high-level, device-independent hints encapsulating unique storage device characteristics can achieve significant I/O performance gains without breaking the established abstraction of a storage device as a linear address space of fixed-size blocks. A piece of system software (here referred to as storage manager), which translates application requests into individual I/Os, can automatically match application access patterns to the provided characteristics. This results in more efficient utilization of storage devices and thus improved application performance. This dissertation (i) identifies specific features of disk drives, disk arrays, and MEMS-based storage devices not exploited by conventional systems, (ii) quantifies the potential performance gains these features offer, and (iii) demonstrates on three different implementations (FFS file system, database storage manager, and disk array logical volume manager) the benefits to the applications using these storage managers. It describes two specific attributes: the access delay boundaries attribute delineates efficient accesses to storage devices and the parallelism attribute exploits the parallelism inherent to a storage device. The two described performance attributes mesh well with existing storage manager data structures, requiring minimal changes to their code. Most importantly, they simplify the error-prone task of performance tuning. Exposing performance characteristics has the biggest impact on systems with regular access patterns. For example in database systems, when decision support (DSS) and on-line transaction processing (OLTP) workloads run concurrently, DSS experiences a speed up of up to 3X, while OLTP exhibits a 7% speedup. With a single layout taking advantage of access parallelism, a database table can be scanned efficiently in both dimensions. Additionally, scan operations run in time proportional to the amount of query payload; unwanted portions of a table are not touched while scanning at full bandwidth

Matching Database Access Patterns to Storage Characteristics

Today&apos;s storage interfaces hide device-specific details, simplifying system development and device interoperability. However, they prevent database systems from exploiting devices&apos; unique performance characteristics. Abstract and device-independent annotations to existing storage interfaces can cleanly expose key device characteristics that improve performance and simplify manual tuning. By automatically matching access patterns to device strengths, a database storage manager can achieve robust performance even with workloads competing for the same storage resource. For example, disk-optimized accesses result in simultaneous improvement of up to 3x for DSS workloads and 7% for a competing OLTP workload. As another example, accesses to relational tables can take advantage of MEMS-based storage parallelism to achieve order of magnitude improvements in selective scans