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Biomedical subjects

R Conn

Publications and source records attributed to R Conn.

10 recordsLinked to original sources

Signature authentication by forensic document examiners.

We report on the first controlled study comparing the abilities of forensic document examiners (FDEs) and laypersons in the area of signature examination. Laypersons and professional FDEs were given the same signature-authentication/simulation-detection task. They compared six known signatures generated by the same person with six unknown signatures. No a priori knowledge of the distribution of genuine and nongenuine signatures in the unknown signature set was available to test-takers. Three different monetary incentive schemes were implemented to motivate the laypersons. We provide two major findings: (i) the data provided by FDEs and by laypersons in our tests were significantly different (namely, the hypothesis that there is no difference between the assessments provided by FDEs and laypersons about genuineness and nongenuineness of signatures was rejected); and (ii) the error rates exhibited by the FDEs were much smaller than those of the laypersons. In addition, we found no statistically significant differences between the data sets obtained from laypersons who received different monetary incentives. The most pronounced differences in error rates appeared when nongenuine signatures were declared authentic (Type I error) and when authentic signatures were declared nongenuine (Type II error). Type I error was made by FDEs in 0.49% of the cases, but laypersons made it in 6.47% of the cases. Type II error was made by FDEs in 7.05% of the cases, but laypersons made it in 26.1% of the cases.

Expert Testimony↗

Dichotic listening in college students who report auditory hallucinations.

College students were placed in 2 groups, hallucinators and nonhallucinators, on the basis of their responses to a verbal hallucinations questionnaire. Both groups were given a consonant-vowel version of a Dichotic Listening Test under 3 conditions: nonforced, forced-right, and forced-left. When hallucinators were instructed to attend to the left ear stimuli (forced-left condition), they had fewer correct responses to right ear syllables than did nonhallucinators. This resulted in a left ear advantage for hallucinators. When nonhallucinators were instructed to attend to the left ear, they maintained a right ear advantage. Results suggest that auditory hallucinations in college students are associated with differences in hemispheric functioning.

Adult↗

Reduction of anxiety about death: need for beliefs about immortality.

It was hypothesized that individuals who are reminded of their own mortality will experience anxiety which is reduced by an increased need for belief in immortality. A questionnaire assessing the need for literal and two forms of symbolic immortality was developed. Analysis showed that awareness of mortality increased scores on the need for literal immortality but not on either form of symbolic immortality.

Adult↗

Myocardial revascularization: results relative to extensiveness.

We analyzed 13,788 patient-years of follow-up of 2,628 consecutive patients who had had primary isolated coronary artery bypass. We then assessed late results relative to the number of coronary artery bypasses done. There were no significant differences in the incidence of survival, angina-free status, nonfatal acute myocardial infarction, repeat coronary artery bypass, or cardiac deaths relative to the number of bypasses in patients with single or double vessel disease. Patients with three vessel disease had significantly increased incidence of angina-free status and significantly decreased incidences of nonfatal acute myocardial infarctions and repeat coronary artery bypass with increasing number of bypasses performed. In this study, we found no advantage in performing increasing numbers of bypasses in patients with single or double vessel disease, but there was definitely such an advantage in patients with triple vessel disease.

Coronary Artery Bypass↗

Heparin necrosis. An anticoagulation syndrome.

Lesions indistinguishable from coumarin necrosis developed in three patients who were given heparin sodium subcutaneously. Two of the patients had received only heparin while another had also received coumarin. Heparin necrosis should be added to the list of complications of anticoagulation therapy.

Aged↗

Thrombophlebitis and thromboembolism: results of a prospective study.

Thrombophlebitis leading to pulmonary embolism has been stated to cause as many as 9% of hospital deaths. Its diagnosis, sites of common occurrence, treatment and immediate sequelae have long been controversial subjects. A prospective study of thrombophlebitis was set up to evaluate these problems. One hundred and sixty-six patients diagnosed clinically as having thrombophlebitis or pulnmonary embolus were studied with the ultrasonic flow detector (doppler). To assess the stated accuracy of this instrument, venograms were done when possible. The doppler proved in this series to be 93% accurate as compared to venography which is comparable to other series. Pulmonary scans and angiograms were obtained from patients suspected of having pulmonary emboli. Results were as follows: 1) Of 113 patients suspected of having thrombophlebitis clinically, only 26 (23%) of the cases were confirmed by doppler; 2) Of 53 patients suspected of having pulmonary embolus clinically, only 18 (34%) had confirmation by scan, angiogram or doppler; 3) Of 39 patients in this series who had thrombophlebitis, 11 (23%) were not suspected of having lower extremity venous disease until pulmonary embolus occurred, 4) Calf vein thrombosis without additional proximal occlusion was present in only 10% of cases; and 5) Thirty per cent of doppler or venographically proven cases of thrombophlebitis occurred after orthopedic injuries or operations. It was concluded that physical examination alone was grossly inaccurate in determining the recurrence of lower extremity thrombosis. In fact physical examination alone appeared to select out for treatment large numbers of patients without venous disease while a significant number of patients with thrombophlebitis remained clinically asymptomatic until pulmonary embolism occurred. Most deep venous disease was found in the larger veins above the knee, explaining the paucity of diagnostic symptoms in these individuals. The ultrasonic flow detector was found to be an extremely accurate, simple and rapid bedside test that could be applied daily to the high risk groups. The appearance of thrombosis could then be treated with heparin with excellent prospects of preventing occurrence of pulmonary embolus.

Angiography↗