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At least 541 records · Page 30Linked to original sources
PubMed1999

Analysis of injury severity and vehicle occupancy in truck- and non-truck-involved accidents.

The impact that large trucks have on accident severity has long been a concern in the accident analysis literature. One important measure of accident severity is the most severely injured occupant in the vehicle. Such data are routinely collected in state accident data files in the U.S. Among the many risk factors that determine the most severe level of injury sustained by vehicle occupants, the number of occupants in the vehicle is an important factor. These effects can be significant because vehicles with higher occupancies have an increased likelihood of having someone seriously injured. This paper studies the occupancy/injury severity relationship using Washington State accident data. The effects of large trucks, which are shown to have a significant impact on the most severely injured vehicle occupant, are accounted for by separately estimating nested logit models for truck-involved accidents and for non-truck-involved accidents. The estimation results uncover important relationships between various risk factors and occupant injury. In addition, by comparing the accident characteristics between truck-involved accidents and non-truck-involved accidents, the risk factors unique to large trucks are identified along with the relative importance of such factors. The findings of this study demonstrate that nested logit modeling, which is able to take into account vehicle occupancy effects and identify a broad range of factors that influence occupant injury, is a promising methodological approach.

Accidents, Traffic↗
PubMed2006

The correlation dimension identifies B-cell immunoglobulin light chain restriction in peripheral blood flow cytometry data.

The correlation dimension (D2) is a mathematical tool that quantifies dimensional properties of fractals. We set out to determine whether immunoglobulin light chain restriction (LCR) in B-cell lymphoproliferative disorders (BCLPDs) could be identified using the D2. The D2 was calculated from flow cytometry data files (FCS 2.0) from a training set of peripheral blood specimens from 22 patients with and 23 patients without BCLPD. A cutoff value derived from the training set was applied to a validation set of 69 patients with and 64 patients without BCLPD. In the training set, all BCLPDs had a D2 of less than 0.72 (CD19-gated kappa-lambda data). When this cutoff was applied to the validation set, the D2 had sensitivity and specificity values of 88% and 98%, respectively. The D2 can identify LCR in peripheral blood flow cytometry data. It offers operator-independent data analysis and may be useful in objectively quantifying differences in data distribution.

Antigens, CD19↗
PubMed1997

Optimization of a low-cost truly preemptive multitasking PC diagnostic workstation.

The Windows 95/NT operating systems (Microsoft Corp, Redmond, WA) currently provide the only low-cost truly preemptive multitasking environment and as such become an attractive diagnostic workstation platform. The purpose of this project is to test and optimize display station graphical user interface (GUI) actions previously designed on the pseudomultitasking Macintosh (Apple Computer, Cupertino, CA) platform, and image data transmission using time slicing/ dynamic prioritization assignment capabilities of the new Windows platform. A diagnostic workstation in the clinical environment must process two categories of events: user interaction with the GUI through keyboard/mouse input, and transmission of incoming data files. These processes contend for central processing units (CPU) time resulting in GUI "lockout" during image transmission or delay in transmission until GUI "quiet time." WinSockets and the Transmission Control Protocol/Internet Protocal (TCP/IP) communication protocol software (Microsoft) are implemented using dynamic priority timeslicing to ensure that GUI delays at the time of Digital Imaging and Communications in Medicine (DICOM) file transfer do not exceed 1/10 second. Assignment of thread priority does not translate into an absolute fixed percentage of CPU time. Therefore, the relationship between dynamic priority assignment by the processor, and the GUI and communication application threads will be more fully investigated to optimize CPU resource allocation. These issues will be tested using 10 MB/sec Ethernet and 100 MB/sec fast and wide Ethernet transmission. Preliminary results of typical clinical files (10 to 30 MB) over Ethernet show no visually perceptible interruption of the GUI, suggesting that the new Windows PC platform may be a viable diagnostic workstation option.

Algorithms↗
PubMed1998

Digital archival and exchange of events in a simple format for polygraphic recordings with application in event related potential studies.

This paper describes a simple method of event encoding as an extension to a previously defined standard format, the European Data Format (EDF). The specification ensures full backward compatibility with the existing definition. By using this extension, the format can be used to store both continuous recordings and selected epochs of recordings. The encoding is performed in a channel of event-codes or in a pseudo-channel for annotations. Standardisation of event encoding is discussed. Decoding of events or annotations from the extended format is implemented at the application level. Existing programs that do not support the new encoding scheme still operate correctly and can simply ignore the new channels in processing 'extended' data files. The event encoding is also compatible with EDF's capability to encode channels of different sampling frequency.

Data Interpretation, Statistical↗
PubMed1984

The design of the Epidemiologic Catchment Area surveys. The control and measurement of error.

Several methods are used to minimize and measure error in the NIMH Epidemiologic Catchment Area program. Sampling methods involve the inclusion of group quarters such as prisons, nursing homes, and mental hospitals in the sample frame and the use of probability sampling throughout. Interviewing, methods include use of identical diagnostic interview protocols, centralized training of interview supervisors, standard instructions to interviewers, and reinterview of a subsample by clinicians. In the area of completion, the methods include a 75% to 80% respondent completion rate, a 95% or greater completion rate for individual questions, use of informant interviews where necessary, and statistical adjustments to correct for low completion rates in some subgroups. Analytic methods include use of a computerized diagnostic algorithm, common estimation formulas on identically formatted data files, and estimation of exact variances that take account of the multistage sample design.

Catchment Area, Health↗
PubMed2005

The application of 2-D dual nanoscale liquid chromatography and triple quadrupole-linear ion trap system for the identification of proteins.

2-D nanoscale LC combined with a triple quadrupole-linear ion trap mass spectrometer was applied to the analysis of a complex peptide mixture. A 2-D dual nanoscale LC-MS/MS system was compared to a conventional one. Peptides were separated with a strong cation exchange (SCX) microcolumn in the first dimension and two C18 nanocolumns were used as second dimension. MS experiments were performed using information-dependent data acquisition, where two precursor ions were selected from an enhanced MS (EMS) or an enhanced multicharged ion (EMC) as survey scan. The major benefit of EMC instead of EMS was a two-fold reduction of the data file and a 15% increase of characterized proteins. The advantage of the 2-D dual nanoscale LC-MS/MS system versus the conventional 2-D nanoscale LC-MS/MS system was reflected in the significant increase of peptides which were successfully identified within the same time frame. The first factor contributing to this increase was that the mass spectrometer was collecting twice the number of relevant MS/MS data. The second factor is the use of twice the number of SCX salt fractions in the first dimension, allowing a better sample fractionation, thereby reducing the number of peptides transferred to the second chromatographic dimension per salt fraction.

Animals↗
PubMed2004

Are we winning or losing the war on cancer? Deciphering the propaganda of NCI's 33-year war.

The National Cancer Institute (NCI) and collaborating agencies have proclaimed great progress in the U.S. "war on cancer," while at the same time presenting more reasons for concern than celebration. We reviewed various documents and data files and found that incidence and mortality rates for all cancer sites combined remain higher than they were when the "war on cancer" was declared in 1971, despite very recent, modest decreases. The burden of the disease has risen from three million to nearly ten million people. Black Americans, men of all races, and other segments of the population disproportionately bear the burden of cancer. We also looked at data for malignant breast cancer and found that incidence rates increased 36% from 1973 to 2000, while mortality for all population groups combined declined slightly. Breast cancer mortality is 34% higher among black women than among white women, even though white women are generally more likely to get the disease. The $50 billion spent on the "war on cancer" over the last 33 years has yielded few gains. The NCI's resources must be refocused on preventing cancers we know how to prevent.

Journal Article↗
PubMed1976

Interactive editing of biomedical data.

Editing options of an interactive graphical-biometry statistical system are described. A method for screening using a highly reduced data file is illustrated. By utilizing properties of sample Fourier coefficients, the problem of component overlap can be resolved. This, in turn, tends to free edited statistical information from the contamination or truncation inherent in the usual screening process.

Data Display↗
PubMedDate not supplied

The Thoratec mobile computer: initial in-hospital and outpatient experience.

The purpose of this study was to test the operational effectiveness of the Thoratec mobile computer for monitoring and adjusting the portable TLC-II pneumatic driver. The TLC-II portable driver is approved by the Food and Drug Administration for use with either the paracorporeal ventricular assist device (VAD) or the Implantable Thoratec VAD. Currently, data log/file retrieval, changing device parameters, and initial VAD set-up is done with the cart mounted docking station. Thoratec has developed a tablet computer to perform the same tasks. The tablet computer weighs 3.2 lbs and has a 10.4 inch display. The mobile computer was evaluated in the clinic and multiple hospital settings as a mobile substitute for the docking station. For 120 consecutive days, the tablet computer was used exclusively for data file retrieval, changing device parameters, and initial VAD set up of the TLC-II portable drivers. Five patients, four paracorporeal VAD and one Implantable Thoratec VAD, using eight TLC-II portable drivers were evaluated. All patients were discharged home and followed as outpatients. The tablet computer was used by the VAD coordinator, two nurse clinicians, a perfusionist, and a research assistant. A total of 59 individual uses were performed (data retrieval, 46; parameter changes, 5; initial VAD set up, 8). Data were successfully obtained in all cases. Documentation of programmed settings and driver operation was achieved without difficulty.

Ambulatory Care Facilities↗
PubMed1995

Pilot trials of PDF symbology as a means of transfering data on blood units between transfusion centres.

PDF 417, a two-dimensional barcode, was used as a portable data file to transfer key information on blood units and delivery documentation between two Regional Blood Transfusion Centres. Multiple Codabar messages currently displayed on blood packs, as well as other useful information, i.e. microbiology conformance, were encoded in a 45-character single PDF barcode. The delivery note which accompanied each consignment of blood consisted of a series of PDF barcodes, each representing 20 blood units. Computer validation showed 100% reconciliation of PDF data with Codabar data. Readability of the code was excellent with a greater than 98% first-pass read rate. The delivery note PDF barcode identified eight operator errors which would have been undetected by the present manual system. We conclude that PDF 417 is an effective, secure and space efficient means of transferring data associated with the transfer of blood.

Blood Banks↗
PubMed2003

Development and assessment of a new radioactive decay database used for dosimetry calculation.

The present paper discusses the technical issues and a scheme for their resolution before undertaking the development of a new radioactive decay database to succeed ICRP38. The scheme consists of the following procedures. (1) The consistency of nuclear structure data files used as input to the computer code EDISTR is established by referring to the latest nuclear parameters and by comparing the computed energies of emitted radiations with total decay energy. (2) A method for calculating detailed spectra of X rays and Auger electrons is incorported into EDISTR to enhance the treatment of atomic relaxation processes initiated by electron vacancies from internal conversion and electron capture. (3) Quality assurance of the compiled data is undertaken by comparisons with experimental data and other decay databases prepared from different computer codes and libraries. JAERI and ORNL are cooperating to implement the scheme in order to assemble a comprehensive radioactive decay database including over 1000 nuclides.

Database Management Systems↗
PubMed2006

Assessment of quality of continuous intracranial pressure recordings in children.

BACKGROUND: Bad quality of continuous intracranial pressure (ICP) recordings may potentially give wrong diagnostic information. METHOD: This study examined the ICP recordings of 33 children undergoing ICP monitoring during a 12-month period. Their ICP recordings were stored as raw data files and analyzed retrospectively. An automatic algorithm applied to every subsequent 6-second time window of each recording assessed the quality of ICP recordings. Time windows containing 4-18 cardiac beat-induced single ICP waves were accepted; time windows containing artifact-induced pressure waves due to noise in the signal were rejected. For every ICP recording, the number of accepted and rejected time windows were determined. In addition, the raw data ICP signal was assessed by visual inspection to verify the automatic algorithm. Two methods of computing mean pressure of a time window are compared; mean ICP was either computed according to current practice independent of the presence or absence of single ICP waves or computed only for single ICP waves within the time window (mean(SW) ICP). RESULTS: In 4 of the 33 patients (12%), more than 70% of the time windows of their ICP recordings were rejected; in 3 patients 95-100% of time windows were rejected. Visual inspection of the raw ICP signals confirmed the absence of single ICP waves. In these cases, computing mean(SW) ICP, not by mean ICP, revealed the bad signal quality. CONCLUSIONS: This retrospective study showed that in 3 of 33 patients (9%) the quality of the ICP recordings was so bad that they gave wrong diagnostic information. One way of obtaining quality control is to compute mean(SW) ICP, determined only for cardiac beat-induced single ICP waves within a time window.

Adolescent↗
PubMed1997

Predicting ad libitum dry matter intake and yield of Holstein cows.

Two data files, one from New Hampshire (n = 3308) and one from Georgia (n = 678), containing 4-wk or weekly means, respectively, of ad libitum dry matter intakes (DMI) and related variables were used to predict DMI and yields of 4% fat-corrected milk and milk protein in lactating Holstein cows. The DMI ranged from 5.9 to 30.4 kg/d, and milk yield ranged from 5.8 to 64.3 kg/d. Because of the lack of data from < 14 d in milk, prediction was not possible for the first 2 wk of lactation. Factors considered for inclusion in the DMI prediction model were parity number (1 or > or = 2), treatment with bovine somatotropin (bST), day of year, days in milk, minimum (nighttime) temperature-humidity index, body weight, 4% fat-corrected milk yield, milk protein yield, and corn silage and total silage percentages in forage dry matter. In separate models, the silage predictors were replaced with more specific descriptors of ration dry matter, including percentages of crude protein, fat (ether extract plus soaps of fatty acids), concentrate, acid detergent fiber or neutral detergent fiber, and forage acid detergent fiber or neutral detergent fiber. The square and sometimes natural logarithm of predictors were included in models, which then were subjected to a stepwise backward elimination option of a multiple regression procedure. Several useful equations were developed to predict ad libitum DMI; the best models accounted for about 80% of the variability in DMI, and standard deviations were < 9% of mean DMI. Depression in DMI related to heat stress was higher in pluriparous cows than in primiparous cows (22% vs. 6%). The negative coefficient for effects of bST treatment on DMI suggested that milk yield increased proportionally more in response to bST than did DMI. About 74 to 77% of DMI predictions were within 2 kg/d of observed DMI.

Animals↗
PubMed1989

Quantitative analysis of platelet activating factor using fast atom bombardment/tandem mass spectrometry.

A procedure is described for the quantitative determination of platelet activating factor (PAF) using stable isotope dilution and fast atom bombardment/tandem mass spectrometry. Low-energy collisional activation of the [M + H]+ ion of PAF yields a single daughter ion of m/z 184, characteristic of phosphocholine derivatives. For precise and accurate quantification, the internal standard is (2H3)acetyl-hexadecyl PAF, which yields an analogous daughter ion of m/z 185. Quantitative analyses are based on limited mass-range parent ion scanning with transmission of daughters of m/z 184 and 185 during alternate scans; all scans are accumulated into a single data file to facilitate determination of the analyte/internal standard response ratio. Analysis of authentic hexadecyl PAF indicates a low-picogram detection limit. The method has been applied to the determination of PAF in preparations of human neutrophils stimulated by addition of a calcium ionophore. Concentrations of PAF of 7-17 ng/10(6) cells were observed, in keeping with earlier reports. The method has been validated by standard addition and dilution experiments. Comparison of data obtained by the new procedure and those obtained by a method involving gas chromatography/electron capture mass spectrometry of dephosphorylated and derivatized PAF showed excellent agreement.

Calcimycin↗
PubMed2000

Proteome analysis of mouse brain: two-dimensional electrophoresis profiles of tissue proteins during the course of aging.

Mouse brain proteins were isolated from five regions (cerebellum, cerebral cortex, hippocampus, striatum, and cervical spinal cord) at five ages from the 10th week to the 24th month, and separated by two-dimensional gel electrophoresis (2-DE). 2-DE was carried out with an immobilized pH gradient bar in the first dimension, and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. Over one thousand protein spots were visualized by silver staining and quantified by image processing. In the analyses, 58 protein spots were distinguishable among the above five brain regions, and 17 proteins were shown to be varied in quantity in the course of aging. Partial amino-terminal sequences and/or internal sequences for a total of 301 protein spots were analyzed. One hundred and eighty proteins appeared to have blocked N-termini and 122 proteins were identified. Twenty-seven new proteins were identified by sequence homology search. A mouse brain proteome database was constructed, which consists of the 2-DE map images and the respective spot data files with 15 related references.

Acrylic Resins↗
PubMed1994

Integrated software tools for the evaluation of radiotherapy treatment plans.

PURPOSE: This article announces the availability of a convenient and useful software environment for the evaluation of three-dimensional (3D) radiotherapy treatment plans. MATERIALS AND METHODS: Using standards such as American National Standards for Information Systems C and the X Window System allowed us to bring the computation and display of dose-volume histograms, dose statistics, tumor control probabilities, normal tissue complication probabilities, and a figure of merit together under one user interface. These plan evaluation tools are not stand alone, but must interact with a 3D radiation therapy planning system to obtain the required dose matrices and patient anatomical contours. Installation of the software involves a programmer who writes a software bridge between the radiation therapy planning system and the tools, thereby providing access to local data files. This design strategy confines portability issues to one area of the software. RESULTS: Access to the other tools is through the Graphical Plan Evaluation Tool (GPET). GPET coordinates the use of each of the tools and provides graphical facilities for display of their results. Importantly, GPET assures that the displayed results of each tool have been computed with the same input specifications for all treatment plans being compared. For added convenience, the user can rearrange the resultant data to be reviewed in various ways on the video screen. The software design also allows incorporation of customized algorithms and input data for computing tumor control probability and normal tissue complication probabilities, since those currently available are controversial. CONCLUSION: The Graphical Plan Evaluation Tool unifies the simultaneous computation for several analytical tools and graphical display of their results. Within the constraints of the X Window System environment, this assemblage of software tools provides a portable, flexible, and convenient method for the quantitative evaluation of several radiotherapy treatment plans.

Dose-Response Relationship, Radiation↗
PubMed2000

Collaborative Initiatives in the Care of Early Stage Breast Cancer: Reduction in Variation of Breast-Conserving Therapy.

Breast-conserving therapy (BCT) has survival results comparable to those obtained with modified radical mastectomy (MST). However, studies suggest variations in the rates of breast-conserving therapy that are not explained by comorbidities or age. The Virginia Health Quality Center collaborated with 40 Virginia hospitals to address patterns of breast cancer treatment. Medicare Peer Review Organization data files were used to identify all Medicare beneficiaries with a primary diagnosis of breast cancer from January 1, 1992, through June 30, 1993. Explicit chart review was performed on a random sample of patients with early stage disease receiving either BCT or MST. At baseline, the BCT rate was 21.1% after controlling for access to radiation facilities, medical conditions, and demographic variables. Hospitals with the highest rates of appropriate BCT served as resources for the project. We provided data on BCT rates to 40 participating hospitals. Hospitals then submitted comprehensive plans to address the performance of BCT. A four-step cooperative improvement intervention was employed to initiate and sustain changes at the hospital level. Interventions included individual hospital feedback, dissemination of model cancer care processes at high-performing institutions, and integration of oncology services for breast cancer treatment decisions. One year after implementation, the overall BCT rate in Virginia increased to 25.5%. Hospitals with the lowest BCT rates increased their average rate from 6.6% to 21.2%. Middle tercile hospitals increased BCT rates by 10%. Variation between the lowest and highest terciles was reduced to 9%. Variation in BCT rates can be reduced by a collaborative program centered on addressing processes of care for breast cancer treatment for Medicare patients with early stage disease.

Journal Article↗
PubMed1998

Survey finds states widen reach of Medicaid risk programs.

Data File: What will industry trends mean for Medicaid providers? A new study details industry changes in Medicaid risk and concludes that providers will see new, more medically complicated and higher costing populations. Here are the details and some interesting statistics--from types of covered populations to marketing practices.

Capitation Fee↗