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PubMedDate not supplied

An automated method for analysis and visualization of laser Doppler velocimetry data.

The analysis and visualization of large data sets collected by use of laser Doppler velocimetry has presented a challenge to researchers using this technique to investigate complex flow fields. This paper describes an automated procedure for analysis and animation of two- and three-dimensional laser Doppler velocimetry data. The procedure consists of a suite of FORTRAN programs for calculating phase window averages of velocity and the Reynolds stress tensor, calculating the principal normal stresses, maximum shear stresses, and preparation of data files for input into Plot-3D compatible data visualization software. An example application of these techniques to data collected from an in vitro investigation of the retrograde flow field associated with a bileaflet mechanical heart valve is also presented.

Algorithms↗
PubMed2006

SPIRE: the SPIDER reconstruction engine.

SPIRE is a Python program written to modernize the user interaction with SPIDER, the image processing system for electron microscopical reconstruction projects. SPIRE provides a graphical user interface (GUI) to SPIDER for executing batch files of SPIDER commands. It also lets users quickly view the status of a project by showing the last batch files that were run, as well as the data files that were generated. SPIRE handles the flexibility of the SPIDER programming environment through configuration files: XML-tagged documents that describe the batch files, directory trees, and presentation of the GUI for a given type of reconstruction project. It also provides the capability to connect to a laboratory database, for downloading parameters required by batch files at the start of a project, and uploading reconstruction results at the end of a project.

Computational Biology↗
PubMed1997

Concordance of Medicare data and population-based clinical data on cataract surgery utilization in Olmsted County, Minnesota.

The authors assessed concordance of local Medicare health care utilization data on cataract surgery and estimates generated using the databases of the Rochester Epidemiology Project, which capture virtually all medical care received by residents of Olmsted County, Minnesota. The Rochester Project databases identified 1,353 primary cataract extractions performed in Olmsted County between October 1989 and December 1993 among county residents aged > or = 65 years. Medicare data identified 1,148 claims-84.8% of the number of procedures identified by the Rochester Project. Ratios of numbers of encounters (Medicare/Rochester Project) were 189/350 (0.540) for 1992 versus 959/1,003 (0.956) for the other years combined. Changes in Medicare data file transfer procedures may have produced the 1992 data shortfall. Medicare data should periodically be compared with source data to assess concordance.

Aged↗
PubMed2004

Role of the physician in childhood obesity.

OBJECTIVE: To suggest the role of the practicing physician in examining and treating childhood obesity. How should obesity be determined at clinical examination? Is there an obesity epidemic? What is the likely influence of obesity upon current and future health? What are the causes of obesity, and what does this imply for prevention and treatment? DATA SOURCES: Relevant articles in Medline and personal files. DATA SYNTHESIS: The 80th and 95th percentiles of body mass index and skinfold readings provide the most commonly accepted indices of overweight and obesity in the child. Over the last 20 years, the proportions of overweight and obese children have increased in both indigenous populations and most developed societies. Current methods of assessing physical activity and diet during childhood lack the precision to establish the primary cause of the obesity epidemic, but correlational analysis shows a close relationship between body fat content and a decline in daily energy expenditures. Immediate consequences of childhood obesity include an increased prevalence of atherosclerotic plaques, hypertension, and an adverse lipid profile, with a poor self-image that limits participation in physical activity. Tracking is such that many obese children become obese adults, and in consequence, the long-term risks of cardiovascular and all-cause deaths are increased. The prevention of obesity is easier than its cure. A combination of increased lifestyle activities, less sedentary behavior, and dietary modification seems the most effective approach. This should be supported by the use of behavioral modification techniques and changes in the urban environment that encourage an active lifestyle. CONCLUSIONS: The pediatric physician can contribute to the control of obesity by monitoring body mass index and skinfold thicknesses in all patients. Children above the 50th percentile of body fat need dietary modification and a greater amount of moderate physical activity. Physicians should also advocate quality daily physical education and an environment that encourages adoption of an active lifestyle.

Adolescent↗
PubMed2004

A review of the 'Statistical Analysis for Genetic Epidemiology' (S.A.G.E.) software package.

The 'Statistical Analysis for Genetic Epidemiology' (S.A.G.E.) software package is an integrated, comprehensive package of computer programs designed to perform many of the different analyses required in the study of genetic epidemiology. It offers a graphical user interface for most platforms and, unlike many programs available in the public domain, is flexible in both receiving many types of input files and in allowing the user to choose among output files. All of the programs accept the same data files and together provide the means to perform familial correlation, segregation, linkage and association analyses, as well as many of the ancillary analyses that help achieve these goals. Many, but not all, of the same or similar analyses can be performed (with more difficulty) using publicly available freeware. The primary limitations of S.A.G.E. at present are the lack of software for estimating haplotypes or for identifying probable double recombinants in linkage analysis. S.A.G.E. is continually being extended and upgraded, however, with automatic downloading of the latest version always available to users.

Databases, Genetic↗
PubMed2006

Electronic patient data confidentiality practices among surgical trainees: questionnaire study.

INTRODUCTION: The objective of this work was to evaluate the safeguards implemented by surgical trainees to protect the confidentiality of electronic patient data through a structured questionnaire sent to Northern Ireland surgical trainees. PARTICIPANTS AND METHODS: A group of 32 basic and higher surgical trainees attending a meeting of the Northern Ireland Association of Surgeons-in-Training were invited to complete a questionnaire regarding their computer use, UK Data Protection Act, 1988 registration and electronic data confidentiality practices. RESULTS: Of these 32 trainees, 29 returned completed questionnaires of whom 26 trainees regularly stored sensitive patient data for audit or research purposes on a computer. Only one person was registered under the Data Protection Act, 1988. Of the computers used to store and analyse sensitive data, only 3 of 14 desktops, 8 of 19 laptops and 3 of 14 hand-held computers forced a password logon. Of the 29 trainees, 16 used the same password for all machines, and 25 of 27 passwords were less than 8 characters long. Two respondents declined to reveal details of their secure passwords. Half of all trainees had never adjusted their internet security settings, despite all 14 desktops, 16 of 19 laptops and 5 of 14 hand-helds being routinely connected to the internet. Of the 29 trainees, 28 never encrypted their sensitive data files. Ten trainees had sent unencrypted sensitive patient data over the internet, using a non-secure server. CONCLUSIONS: Electronic data confidentiality practices amongst Northern Ireland surgical trainees are unsafe. Simple practical measures to safeguard confidentiality are recommended.

Computer Security↗
PubMed1999

Method R estimates of heritability for milk, fat, and protein yields of United States dairy cattle.

Heritabilities for milk, fat, and protein yields were estimated from first lactation data used for USDA-Dairy Herd Improvement Association (DHIA) genetic evaluations. Contemporary group assignments and standard deviations within herd-year were determined with the procedure used for national evaluations. Pedigree data were included for animals born since 1970; yield data were included for cows born since 1980. Lactation records were divided into four mutually exclusive data sets based on standard deviations. Ranges for standard deviations were chosen so that data sets were approximately equal in size. Method R was used to estimate heritability with 25 different random samples of half of the data for each data set. Because of the large number of Holstein observations, estimates of heritability for Holsteins were based on random subsets of the complete data file; each subset included approximately 5% of the data. Mean heritability estimates increased with standard deviations, and estimates ranged from 0.18 to 0.51 across breeds. Repeatability estimates for milk yield of Holsteins were approximately 0.50 and did not change with standard deviation. These heritability estimates were higher than those previously used in the USDA-DHIA genetic evaluation. Heritability used in the USDA-DHIA genetic evaluation have been increased based on these results.

Animals↗
PubMed1999

Application of the medical data warehousing architecture EPIDWARE to epidemiological follow-up: data extraction and transformation.

In this paper, we present an application of EPIDWARE, medical data warehousing architecture, to our epidemiological follow-up project. The aim of this project is to extract and regroup information from various information systems for epidemiological studies. We give a description of the requirements of the epidemiological follow-up project such as anonymity of medical data information and data file linkage procedure. We introduce the concept of Data Warehousing Architecture. The particularities of data extraction and transformation are presented and discussed.

Computer Systems↗
PubMed2006

Infant mortality statistics from the 2003 period linked birth/infant death data set.

OBJECTIVES: This report presents 2003 period infant mortality statistics from the linked birth/infant death data file by a variety of maternal and infant characteristics. The linked file differs from the mortality file, which is based entirely on death certificate data. METHODS: Descriptive tabulations of data are presented and interpreted. Excluding rates by cause of death, the infant mortality rate is now published with two decimal places. RESULTS: The U.S. infant mortality rate was 6.84 infant deaths per 1,000 live births in 2003, a return to the rate in 2001, compared with 6.95 in 2002. Infant mortality rates ranged from 4.83 per 1,000 live births for Asian or Pacific Islander mothers to 13.60 for non-Hispanic black mothers. Among Hispanics, rates ranged from 4.57 for Cuban mothers to 8.18 for Puerto Rican mothers. Infant mortality rates were higher for those infants whose mothers were born in the 50 States and the District of Columbia, were unmarried, or smoked during pregnancy. Infant mortality was also higher for male infants, multiple births, and infants born preterm or at low birthweight. Infants born at the lowest birthweights and gestational ages have a large impact on overall U.S. infant mortality. Nearly one-half (49 percent) of all infant deaths in the U.S. in 2003 occurred to the 0.8 percent of infants whose birthweight was less than 1,000 grams. The three leading causes of infant death--Congenital malformations, low birthweight, and SIDS--taken together accounted for 45 percent of all infant deaths. For infants of non-Hispanic black mothers, the cause-specific infant mortality rate for low birthweight was nearly four times that for infants of non-Hispanic white mothers. For infants of non-Hispanic black and American Indian mothers, the SIDS rates were more than double the rate for non-Hispanic white mothers.

Birth Certificates↗
PubMedDate not supplied

A computerized information system for diabetes services.

The utilization of a computer-assisted information system may be both useful and efficacious in the care and follow-up of diabetic patients. The model developed by us operates under GCOS-6 on a Microsystem 6/10 Honeywell computer (20 MB hard-disk storage, 512 kb central memory) and allows the creation of clinical data files for individual patients, statistical analysis of the data, and a print-out of clinical records. The package, which may be employed on a multi-user system, is supplied with an easy to understand user's manual. It represents an effective tool for the precise management of the care of diabetic patients and also provides several opportunities for research.

Diabetes Mellitus↗
PubMed1982

[The computer in radiology. findings obtained by the text rail].

As a dedicated solution for professional classification, the COMRAD (COMputer in RADiology) system makes available a "dialog system" that enables the fully integrated processing of operational layouts or word processing and administration of medical practice. The dialog system is based on data files which enable direct access to all stored data as well as the storage of new data, thus avoiding a multiple input and storage. The operational layout of text processing which is to be introduced by this paper, permits radiological findings to be prepared in a flow text, strictly observing a division of the analysis into a descriptive and a evaluative report. The synthesis of the findings is reached through a dialed description of a pathological condition, which is automatically supplemented for assessment by the pertinent evaluation text including its variables. In contrary of assembling text modules the texts of all not directly dialed findings without pathological changes are automatically incorporated both into the description and into the assessment. The variables may be standard attributes, free attributes and pairing attributes.

Computers↗
PubMed1994

Motorcycle crashes resulting in death and hospitalisation. II: Traffic crashes.

This is the second paper in a series of three that describe the epidemiology of motorcycle crashes in New Zealand that result in death and hospitalisation. The first paper presented an overview of all motorcycle crashes. This paper focuses on traffic crashes. The source of the fatality data was national mortality data files for the years 1978 to 1987 inclusive. The source of the hospitalisation data was the 1988 national morbidity file which records all public hospital discharges in New Zealand. For the period 1978 to 1987, 1,175 fatalities were identified resulting in a mortality rate of 3.5 per 100,000 persons per year. Males aged 15-19 and 20-24 had very high rates (25.2 and 26.4, respectively), especially labourers (40.0) and forestry workers (32). Maori and non-Maori had similar rates. The majority (63%) of the deaths were attributable to a collision with another motor vehicle. During 1988 2,222 motorcyclists were hospitalised giving an incidence rate of 68.1 per 100,000 persons per year. Males aged 15-19 and 20-24 had very high rates (409 and 416, respectively), especially labourers (355). Maori had a higher morbidity rate than non-Maori (99 versus 61). The most common (40%) crash was a collision with another motor vehicle. The most common sites of injury were the lower limb (43%) and head (23%). Collision crashes were more likely to result in lower limb injury, be more severe, and result in longer stays in hospital.

Abbreviated Injury Scale↗
PubMed1995

The aeromedical risk associated with asymptomatic cholelithiasis in USAF pilots and navigators.

BACKGROUND: The U.S. Air Force (USAF) aeromedical policy regarding incidentally discovered, asymptomatic cholelithiasis required the aircrew to undergo cholecystectomy prior to being considered for return to flying duties. HYPOTHESIS: The merit of continuing this USAF policy was evaluated at the request of the U.S. Air Force Surgeon General. METHODS: A medical literature review of the natural history of cholelithiasis in the general population was completed. The USAF aircrew waiver file (1972-92) and the Ellingson Aerospace Medicine Consultation Service (ACS) data file (1955-92) were reviewed for cases of USAF pilots and navigators with a diagnosis of cholelithiasis or cholecystectomy. Pilot and navigator annual manpower data were obtained from the Air Force Military Personnel Center (1972-92) and used in calculations involving the USAF aircrew waiver file. Surgical morbidity and mortality information was obtained from the Division of Surgery, Wilford Hall Medical Center. RESULTS: Literature review predicted a 1-4% annual rate of acute events in individuals with previous asymptomatic cholelithiasis. Based on KUB radiographs taken at ACS, the prevalence of asymptomatic cholelithiasis in USAF pilots and navigators was estimated to be 2-3%. Of 11,685 pilots and navigators evaluated at the ACS, 80 (0.7%) were diagnosed with cholelithiasis or cholecystectomy. Between 1972 and 1992, an estimated 16,232 man-years of pilot/navigator exposure to asymptomatic cholelithiasis occurred; however, only 50 cases with a diagnosis of cholecystectomy or cholelithiasis were reported in the USAF waiver file. Mortality and morbidity for cholecystectomy, whether performed by open or laparoscopic technique, were reported as 0.2% and 5%, respectively, in the general population. CONCLUSION: The overall incidence of acute cholecystitis within USAF aircrew would not be changed by aeromedical cholecystectomy being performed on aviators with incidentally detected asymptomatic cholelithiasis.

Adult↗
PubMed2000

Patterns of endoscopy use in the United States.

BACKGROUND & AIMS: The aim of this study was to use a large national endoscopic database to determine why routine endoscopy is performed in diverse practice settings. METHODS: A computerized endoscopic report generator was developed and disseminated to gastrointestinal (GI) specialists in diverse practice settings. After reports were generated, a data file was transmitted electronically to a central databank, where data were merged from multiple sites for analysis. RESULTS: From April 1, 1997, to October 28, 1998, 276 physicians in 31 practice sites in 21 states provided 18,444 esophagogastroduodenoscopy (EGD) reports, 20,748 colonoscopy reports, and 9767 flexible sigmoidoscopy reports to the central databank. EGD was most commonly performed to evaluate dyspepsia and/or abdominal pain (23.7%), dysphagia (20%), symptoms of gastroesophageal reflux without dysphagia (17%), and suspected upper GI bleeding (16.3%). Colonoscopy was most often performed for surveillance of prior neoplasia (24%) and evaluation of hematochezia (19%) or positive fecal occult blood test (15%). Flexible sigmoidoscopy was most commonly performed for routine screening (40%) and evaluation of hematochezia (22%). There were significant differences between academic and nonacademic sites. CONCLUSIONS: The endoscopic database can be an important resource for future research in endoscopy by documenting current practice patterns and changes in practice over time.

Colonoscopy↗
PubMed2001

Cross sections of (n,p), (n,alpha) and (n,2n) reactions on some isotopes of zirconium in the neutron energy range of 10-12 MeV and integral tests of differential cross section data using a 14 MeV d(Be) neutron spectrum.

Cross sections were measured for the 90Zr(n,alpha)87mSr, 90Zr(n,2n)89m,gZr, 91Zr(n,p)91mY, 92Zr(n,p)92Y, 94Zr(n,alpha)91Sr and 96Zr(n,2n)95Zr reactions over the neutron energy range of 11.4 to 12.4 MeV and for the 94Zr(n,p)94Y reaction from 9.2 to 12.4 MeV. Nuclear model calculations were performed up to 16MeV. The statistical model incorporating precompound effects reproduces excitation functions of the three major threshold reactions, namely (n,p), (n,alpha) and (n,2n), quite well. Spectrum averaged cross sections were measured using a thick target Be(d,n) neutron field at Ed = 14 MeV. For the same neutron field averaged reaction cross sections were deduced using the excitation functions measured in this work as well as those given in the ENDF/B-VI, JEF-2, JENDL-3.2, BROND and ADL-3 data files. A comparison of the experimental and deduced integral data helped validating the differential data.

Journal Article↗
PubMed2005

Aging and nonlinear heart rate control in a healthy population.

In recent years more studies are using nonlinear dynamics to describe cardiovascular control. Because of the large dispersion of physiological data, it is important to have large studies with both male and female participants to establish a range of physiological healthy values. This study investigated the effect of gender and age on nonlinear indexes. Nonlinear scaling properties were studied by using 1/f slope (where f is frequency), fractal dimension, and detrended fluctuation analysis short- and long-term correlations (DFAalpha(1) and DFAalpha(2), respectively). Nonlinear complexity was described with correlation dimension (CD), Lyapunov exponent (LE), and approximate entropy (ApEn). The population consisted of 135 women and 141 men (age, 18-71 yr). Twenty-four hour ECG recordings were obtained by using Holter monitoring. The recordings were split into daytime (8 AM-9 PM) and nighttime (11 PM-6 AM). A day-night variation was present in all nonlinear heart rate variability (HRV) indexes, except for the CD in the female population. During the night the percentage of CD values of surrogate data files differing from the CD value of the original data increased. All nonlinear indexes were significantly correlated with age. Deeper analysis per age category of 10 yr showed a stabilization in the age decline of the fractal dimension and ApEn at the age of > or =40 yr. The vagal pathways seemed to be more involved in the generation of nonlinear fluctuations. Higher nonlinear behavior was evident during the night. No clear difference between men and women was found in the nonlinear indexes. Nonlinear indexes decline with age. This can be related to the concept of decreasing autonomic modulation with advancing age.

Adult↗
PubMed1996

Handling missing data in survey research.

Missing data occur in survey research because an element in the target population is not included on the survey's sampling frame (noncoverage), because a sampled element does not participate in the survey (total nonresponse) and because a responding sampled element fails to provide acceptable responses to one or more of the survey items (item nonresponse). A variety of methods have been developed to attempt to compensate for missing survey data in a general purpose way that enables the survey's data file to be analysed without regard for the missing data. Weighting adjustments are often used to compensate for noncoverage and total nonresponse. Imputation methods that assign values for missing responses are used to compensate for item nonresponses. This paper describes the various weighting and imputation methods that have been developed, and discusses their benefits and limitations.

Data Interpretation, Statistical↗