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PubMedDate not supplied

An evaluation of line quality in photocopied signatures.

Qualified forensic document examiners from Canada, USA, Great Britain and Australia participated in this study. They were sent one photocopied signature, together with a set of original known standards to evaluate the line quality of the photocopied signature and compare these characteristics with the standards. They were asked to assess the photocopies for the presence of tremor, hesitation, pen lifts, patching, blunt initial or terminal strokes, and abrupt changes in direction. The authors compared the assessments with the corresponding original signatures. It was possible to determine which line quality characteristics were the most difficult to detect, which indicia of simulation were concealed and what anomalies were introduced by the photocopying process. Results indicated that line quality characteristics can be identified in average quality photocopies. Furthermore, accurate judgements can be made regarding similarities and differences in line quality when comparing a photocopied signature with original known standards. In a few instances, ink line morphology was problematic when striation patterns and ink gooping were misinterpreted as pen lifts, hesitation and patching on the photocopies.

Copying Processes↗
PubMed1997

Manual and computer-aided space analysis: a comparative study.

Recently, computers have been used to measure key landmarks from photocopies of upper and lower study models to increase simplicity, accuracy, and informatics. This is a comparative study to evaluate the accuracy and reliability of computer-aided space analysis. Data were collected from a series of randomly selected study models. All subjects had Angle Class I molar relationships with minor malocclusions such as crowding, rotations, or diastemas. Two investigators independently measured teeth on models with a Vernier gauge that had sharpened caliper tips. Intraexaminer and interexaminer reliability was determined at 0.2 mm. All teeth, to and including the first molars, were measured. Two photocopies of each set of models were made on a photostat machine (Xerox, Japan) and were coded. A template with a ruler was used, to allow the investigator to compensate for any reduction or enlargement error during the photocopying process. The mesiodistal sizes were measured with a digitizer, and results were processed by using a dedicated computer program. Evaluations were done in a double-blind manner. The nonparametric Wilcoxon signed rank test for paired observations to compare median differences between measurements was used. Intraexaminer digitized measurements were almost identical and differed (p < 0.0001) for only one measurement. However, interexaminer manual and digitized measurements differed significantly (p < 0.001) for 20 of the 24 teeth. Nineteen of these digitized tooth measurements were smaller. The mean arch length measurements differed by 4.7 mm (p < 0.0001) in the maxilla and by 3.1 mm (p < 0.0001) in the mandible. The difference between the manual and digitized analyses may be due to the photocopying process. The inability to accurately measure a three-dimensional study cast that has been duplicated in two dimensions, convex structure of teeth, curve of Spee, tooth inclination, and tooth position may play a role. The computer-aided measuring system is reliable, but accurate mesiodistal measurements cannot be made from photocopies of dental models. Manual measurements that use a calibrated gauge produce the most accurate, reliable, and reproducible results.

Calibration↗
PubMed1996

Maintaining confidentiality: health care's ongoing dilemma.

Confidentiality of patient information is an ethical obligation of health care professionals. The exercise of confidentiality is not a simple process; it is dynamic rather than static and must be upgraded with changes in technology. This article discusses some of the common issues that arise in maintaining confidentiality in the health care environment, including spoken and written breaches of confidentiality, use of the computer, confidentiality as an ethical rather than legal obligation, and the use of programs in health care institutions to maintain confidentiality.

Attitude of Health Personnel↗
PubMed2001

Converting a large photographic negative collection to digital form.

Like many media production facilities in recent years, we at the University of Arkansas for Medical Sciences' Media Services have made the transition from silver and wet photographic processes to digital production methods. During that process we found that many of our products had to be transferred from traditional to digital form. One major asset we had was a portrait negative file that contained about 13,000 photographic negatives of nearly 6,000 individuals. These negatives were of individuals currently on staff or who had had their portrait taken while on staff in the past. The oldest of these negatives went back twenty years. About 65 percent of the collection consisted of 4 x 5 black and white negatives and the rest evenly distributed between 120 and 35 mm film formats. Less than 20 percent of the entire collection was color.

Arkansas↗
PubMed2005

In vivo evidence for a recA-independent recombination process in Escherichia coli that permits completion of replication of DNA containing UV damage in both strands.

We have investigated recombination mechanisms promoting the completion of replication in the face of unrepaired DNA damage by transforming an isogenic set of uvrA6 excision-defective Escherichia coli strains with pUC-based plasmids in which each strand carried, at staggered positions, a single thymine-thymine pyrimidine (6-4) pyrimidinone lesion. The distance between the lesions was 28 or 8 bp in one orientation relative to the unidirectional ColE1 origin of replication or, in the other orientation, 30 or 10 bp. C-C mismatches placed opposite each of the T-T photoproducts permit unambiguous detection of the three events that can lead to the completion of replication: sister-strand recombination, translesion replication (TR) on the leading strand, and TR on the lagging strand. We find that E. coli possesses a largely constitutive, recA-independent sister-strand recombination mechanism that allows 9% or more of these severely compromised plasmids to be fully replicated. In one orientation, such recombination depends partly on recG and priA but not on ruvA, ruvB, ruvC, or mutS and is largely independent of recF. In the other orientation, recombination is dependent on none of the genes. The strains used did not contain the cryptic phage encoding recET, which encodes enzymes that promote interplasmid recombination. The nature of the recA-independent recombination mechanism is not known but could perhaps result from a template-strand-switching, or copy choice, process.

Adenosine Triphosphatases↗
PubMed1984

Investigation and control of occupational hazards associated with the use of spirit duplicators.

A Health Hazard Evaluation was conducted by the National Institute for Occupational Safety and Health (NIOSH) to determine if vapors from duplicating fluid (99% methyl alcohol) used in direct-process spirit duplicating machines were causing adverse health effects among teacher aides, or had been responsible for the deaths of three former teacher aides. Death certificates and autopsy data were obtained and evaluated. A self-administered symptom questionnaire was distributed to current teacher aides (exposed group) and to a comparison group of teachers. Fifteen-minute breathing zone air samples for methyl alcohol vapor were collected at operator stations using an infrared gas analyzer. No information supported the claim that the three deaths were related to methyl alcohol exposure. Teacher aides reported significantly more blurred vision, headache, dizziness, and nausea than the comparison group. Concentrations of airborne methyl alcohol ranged from 365-3080 ppm; 15 of 21 measurements exceeded the NIOSH-recommended 15-minute exposure limit of 800 ppm. A mean 96% reduction in vapor concentration was accomplished using inexpensive enclosures and existing room exhaust systems.

Adult↗
PubMedDate not supplied

Development of a high quality film duplication system using a laser digitizer: comparison with computed radiography.

A high quality film-duplication system was developed in order to improve the image quality of duplicated radiographs and to recover improperly exposed films. The system consists of a laser film digitizer, a laser film printer, a workstation, and a magneto-optical disk. Radiographs are digitized by the laser digitizer, processed by the computer for image enhancement, and then printed on a film by the laser printer. A nonlinear density-correction technique is employed in recovering improperly exposed radiographs using the H&D curve of the screen-film system. Using the new duplication system in our department, the average recovery rate was over 80% for chest and abdominal films rejected due to over- or underexposed. The basic imaging properties of the duplication system were compared with those of a Computed Radiography (CR) system and a conventional screen-film system. For low spatial frequencies, the MTF of the CR system is superior to that of the digital duplication system; however, for high spatial frequencies, the MTF of the duplication system is superior. The noise in the duplication system is about half of that in the CR system.

Biophysical Phenomena↗
PubMed2005

Method of duplicating film using the CR system: evaluation of detectability in a simulated nodule.

PURPOSE: Since film processors used for screen-film systems have been decreasing recently, it is becoming difficult to develop duplicating film (Dup film) used conventionally. The purpose of this study was to evaluate the usefulness of the method of duplicating film using a computed radiography (CR) system. MATERIALS AND METHODS: The process of duplicating film using CR is 1) to eliminate energy accumulated on the imaging plate (IP) using white light, 2) to accumulate energy on the whole surface, and 3) to place the original film in piles. 4) After an exposure of white light, duplicated films can be obtained by CR system. In order to evaluate the reproducibiliy of our system, duplicated films were read by experienced observers and receiver operating characteristic (ROC) analysis was carried out. Observers read 50 images with a simulated nodule and 50 images without a simulated nodule. RESULTS: The average Az values were 0.94 for the original films, 0.91 for films duplicated using Dup film, and 0.90 for films duplicated using the CR system. When the two-tailed paired-T test was performed for each result, there were no statistically significant differences at p<0.05. CONCLUSION: The detectability of a simulated nodule for films duplicated using the CR system did not differ from the detectability of films duplicated using Dup film. This method may be a reasonable substitute for the conventional duplication system.

Copying Processes↗
PubMed2003

Oxidative stress and potential free radical damage associated with photocopying. A role for ozone?

OBJECTIVE: To study the relationship between oxidative stress and potential free radical damage associated with photocopying and to explore a role for ozone emitted during the photocopying process. METHODS: 80 photocopying operators (PO) and 80 healthy volunteers (HV) were enrolled in a random control study design, in which the level of lipoperoxide (LPO, thiobarbituric acid reactive substances, TBARS) in erythrocytes and the levels of vitamin C (VC), vitamin E (VE) and beta-carotene (beta-CAR) in plasma as well as the activities of superoxide dismutase (SOD) and catalase (CAT) in erythrocytes were determined by spectrophotometric methods. RESULTS: Compared with the average values of the above biochemical parameters in the HV group, the average value of LPO (TBARS) in erythrocytes in the PO group was significantly increased (P < 0.0001), while the average values of VC, VE and beta-CAR in plasma as well as those of SOD and CAT in erythrocytes in the PO group were significantly decreased (P < 0.0001). Pearson product-moment correlation analysis showed that with the increase of the ozone level in photocopying sites and the PO duration of exposure to ozone, the level of LPO in erythrocytes in the operators was increased (P < 0.001), while the levels of VC, VE and beta-CAR in plasma as well as the activities of SOD and CAT in erythrocytes in the operators were decreased (P < 0.01-0.0001). CONCLUSION: The findings in this study suggest that ozone causes oxidative damage in copier operatives.

Adult↗
PubMed1977

Double-exposure duplication of preoperative and postoperative 2 X 2 transparencies.

Before and after photographs in plastic surgery are an essential part of the patient's record. They also provide visual data to supplement both primary and continuing education lectures. When successive photographs are used in lectures, a sharp visual memory is required to compare effectively the preoperative and postoperative photograph. The method presented in this article uses a specially constructed frame used as an accessory for one of the common commercial slide copiers. This device makes it possible to copy, duplicate, and frame preoperative and postoperative 2 X 2 transparencies onto a single 2 X 2 transparency without any additional work on the original, such as framing, cutting, and remounting. This technique leaves the original preoperative and postoperative 2 X 2 transparency slides intact for possible use elsewhere in the same lecture or subsequent lectures on the same subject.

Audiovisual Aids↗
PubMed1986

Acute-onset sarcoidosis presenting as workplace-related hyperreactive airway disease.

Bechtel et al [Am Rev Respir Dis 124:759-761, 1981] have reported a high prevalence of positive methacholine challenge tests in patients with sarcoidosis. We report a patient with sarcoidosis who was identified because of symptoms resulting from exposure to workplace irritants. The presence of hyperreactive airways was confirmed by a positive methacholine challenge.

Adult↗
PubMed1994

ELF magnetic field exposures in an office environment.

Potential exposures to extremely low frequency (ELF) magnetic fields were investigated in response to worker concerns about an apparent increased spontaneous abortion risk in a payroll office environment. Concern in this office centered on the use of video display terminals (VDTs), which have been investigated as a potential cause of adverse reproductive outcomes among women. In this investigation, magnetic field sources were evaluated using a hand-held survey meter. Emdex datalogging dosimeters were also used to determine full shift personal exposures for 15 women working in the payroll area. On average, the exposures of workers to ELF magnetic fields in the payroll office area ranged from 1.0 to 6.5 mG with a mean of 3.2 +/- 1.5 mG. The results of this study indicate that many sources of ELF magnetic fields, including printers, photocopiers, and the electrical distribution system, can contribute to a worker's exposure in an office environment.

Computer Terminals↗
PubMed2000

An evaluation of employee exposure to volatile organic compounds in three photocopy centers.

Personal and area samples from three copy centres were collected in thermal desorption tubes and analyzed using gas chromatography-mass spectrometry. Real-time personal total volatile organic compounds (TVOC) were measured using a data-logging photoionization detector. Fifty-four different VOCs were detected in the area samples. The maximum concentration measured was 1132.0 ppb (toluene, copy center 3, day 1). Thirty-eight VOCs were detected in the personal samples and concentrations ranged from 0.1 ppb (1,1-biphenyl, p-dichlorobenzene, propylbenzene, styrene, and tetrachloroethylene) to 689.6 ppb (toluene). Real-time TVOC measurements indicated daily fluctuations in exposure, ranging from <71 to 21,300 ppb. The time-weighted average exposures for the photocopier operators on days 1 and 2 were 235 and 266 ppb and 6155 and 3683 ppb, in copy centers 2 and 3, respectively. Personal exposure measurements of individual VOCs were below accepted occupational standards and guidelines. For example, the maximum concentration was 0.3% of the permissible exposure limits (toluene, copy center 3). Exposures were highest in copy center 3; this is likely due to the presence of offset printing presses. It is concluded that photocopiers contribute a wide variety of VOCs to the indoor air of photocopy centers; however, exposures are at least 100 times below established standards.

Air Pollution, Indoor↗