Biomedical subjects

D Shinar

Publications and source records attributed to D Shinar.

At least 19 recordsLinked to original sources

PubMed2001

Self-reports of safe driving behaviors in relationship to sex, age, education and income in the US adult driving population.

This study analyzed the data of a health and safety survey conducted on a representative sample of the adult driving population. The analysis focused on the relationships between self-reported safe driving behaviors (including belt use, observing speed limits, and abstaining from drinking and driving), and demographic characteristics (including sex, age, education and income). The results showed that the three behaviors are quite independent of each other, and, contrary to some stereotypes, there is no single high-risk group that is most likely to violate all three safe driving behaviors. The only consistent effect was that of sex: women reported higher observance rates of all three behaviors. Reported use of safety belts increases with age and education for both men and women. However while for women the reported use increases with income, for males the reported use does not change with income. Complete avoidance of drinking and driving was reported by most drivers in all groups, and the high rates hardly varied across the different age, education, and income groups. The number of people who reported that they observe the speed limit all the time increased with age, but decreased with increasing education and income. The results have implications for identifying violation-specific high-risk groups, and stressing different factors for each.

Adult↗

PubMed2001

Minimum and comfortable driving headways: reality versus perception.

A field study was conducted to evaluate drivers' actual headways in car-following situations, their relationship to the drivers' brake reaction times, and their relationship to the drivers' ability to estimate those headways using different metrics. Drivers were asked to maintain "minimum safe distance" and "comfortable, normal distance with no intention to pass" behind the car ahead. The lead car speeds varied from 50 to 100 km/hr. The results showed that under both sets of instructions, drivers adjusted their distance headways in relation to speed, maintaining constant time headways. A significant portion of the drivers maintained time headways that are considered unsafe in relation to drivers' reaction times. There was no significant relationship between the minimal headways maintained by the drivers and their brake reaction times under conditions of maximum attention and preparedness to apply brakes. Accuracy of spoken estimates of headways varied widely among the three measures used to report perceived headway; meters and car lengths yielded much lower estimates (and ones closer to the actual headways) than did seconds. The results have implications for headway perception, driving safety, driver education, and smart cruise-control design.

Acceleration↗

PubMed2000

Fleet study evaluation of an advance brake warning system.

The advance brake warning system (ABWS) is a mechanism that activates the brake lights in response to a rapid disengagement of the gas pedal, before the driver's foot reaches the brake pedal. Two previous studies showed that (a) such rapid releases of the gas pedal are typically followed by brake activation, and (b) the ABWS can prevent a high percentage of rear-end collisions in which an attentive following driver maintains a headway of 1.0 s or less from the vehicle ahead. In the present study the crash involvement of 764 government cars and light trucks was tracked over an average period of 35 months. The vehicles were matched in pairs--one of each pair with the ABWS and one without it. Data analyses focused on collisions in which the government vehicles were rear-ended. Overall, ABWS-equipped vehicles were not significantly less involved in rear-end collisions. However, an examination of the struck vehicles only showed that the ABWS-equipped vehicles were involved in fewer rear-end collisions per kilometer driven than were the vehicles without the ABWS. In conclusion, despite the theoretical appeal and the results of earlier studies, the fleet study failed to demonstrate that such a system is a cost-effective safety device for the prevention of rear-end crashes. Actual or potential applications include the evaluation of new in-vehicle technologies by a hierarchy of multiple validation studies prior to consideration.

Accidents, Traffic↗

PubMed1999

Trends in safe driving behaviors and in relation to trends in health maintenance behaviors in the USA: 1985-1995.

Specific health and safe driving behaviors of the American adult population during the period 1985-1995, were examined for trends and for consistencies in observing them. The data base consisted of the results of annual surveys conducted on representative samples of 1250 people of the US adult population. Two indices were developed: a Health Index (HI) and a Safety Index (SI). The Health Index reflects the level of practice of six health and disease preventing behaviors (in order of decreasing importance: not smoking, frequent exercises, avoiding fat foods, having an annual blood pressure test, avoiding high-cholesterol foods, and having an annual dental exam). The Safety Index reflects the level of practice of three safe driving behaviors (in order of decreasing importance: wearing safety belts, avoiding drinking and driving, and observing the speed limit). Only a weak association was found among the individual safe driving behaviors, among the individual health maintenance behaviors, and between the two sets of behaviors. Over the 11-year study period the change in the Health Index has been practically and statistically insignificant, whereas the change in the Safety Index was both statistically and practically significant. The small improvement in the Safety Index actually masked a complex pattern of changes in safe driving habits. The three component Safety Index behaviors did not change in the same manner over the 11-year period. The greatest and most consistent increase was in the use of safety belts, with the reported percent who use it all the time increasing from 41.5% in 1985 to 74.1% in 1995 (an increase of 80%). There was also a consistent positive trend in refraining from drinking and driving, but the overall improvement was less dramatic than that reported for use of safety belts: from 71.6% reporting they never drink and drive in 1985 to 79.1% in 1995 (an increase of 10%). Still, it is noteworthy that by 1995 nearly 80% of the people reported they never drink and drive. Finally, obeying the speed limit did not improve over the 11-year period.

Accidents, Traffic↗

PubMed1999

Eye movements of younger and older drivers.

This 2-part study focuses on eye movements to explain driving-related visual performance in younger and older persons. In the first task, participants' eye movements were monitored as they viewed a traffic scene image with a numeric overlay and visually located the numbers in their sequential order. The results showed that older participants had significantly longer search episodes than younger participants, and that the visual search of older adults was characterized by more fixations and shorter saccades, although the average fixation durations remained the same. In the second task, participants viewed pictures of traffic scenes photographed from the driver's perspective. Their task was to assume the role of the driver and regard the image accordingly. Results in the second task showed that older participants allocated a larger percentage of their visual scan time to a small subset of areas in the image, whereas younger participants scanned the images more evenly. Also, older participants revisited the same areas and younger participants did not. The results suggest how aging might affect the efficacy of visual information processing. Potential applications of this research include training older drivers for a more effective visual search, and providing older drivers with redundant information in case some information is missed.

Adult↗

PubMed1998

How automatic is manual gear shifting?

Manual gear shifting is often used as an example of an automated (vs. controlled) process in driving. The present study provided an empirical evaluation of this assumption by evaluating sign detection and recall performance of novice and experienced drivers driving manual shift and automatic transmission cars in a downtown area requiring frequent gear shifting. The results showed that manual gear shifting significantly impaired sign detection performance of novice drivers using manual gears compared with novice drivers using an automatic transmission, whereas no such differences existed between the two transmission types for experienced drivers. The results clearly demonstrate that manual gear shifting is a complex psychomotor skill that is not easily (or quickly) automated and that until it becomes automated, it is an attention-demanding task that may impair other monitoring aspects of driving performance. Actual or potential applications of this research include a reevaluation of the learning process in driving and the need for phased instruction in driving from automatic gears to manual gears.

Adolescent↗

PubMed1996

Duration estimates and users' preferences in human-computer interaction.

Two experiments assessed the effect of various static and dynamic computer 'wait' message displays on (1) subjective estimates of the duration of intervals during which a subject had to wait for the computer's response, and (2) subjective preferences among the different displays. All the static displays led to identical duration estimates. For dynamic displays a direct relation between the rate of changes and the estimate was found. Faster rates led in most cases to increased estimates of duration, and slow-changing graphic displays appeared to have the shortest duration. Subjects preferred epigrams to all other displays, and cumulative graphic displays to a blinking or static WAIT. The rate of change did not affect preference ratings for the graphic displays, whereas slower blink rates were preferred for the WAIT. The results demonstrate that the findings and models from earlier basic research on time estimation are relevant for predicting the subjective assessment of wait-periods. However, users' satisfaction with the displays depends not only on the apparent duration of the wait period, but also on other variables. These should be considered when choosing the display that is shown while users wait for the system to complete a task.

Adult↗

PubMed1995

Drinking and driving of pub patrons in Israel.

A chance sample of people exiting pubs in Israel were interviewed and their blood alcohol concentration (BAC) was measured with a portable breathalizer. Approximately 50% of the people intended to drive away themselves, while 50% were driven by others. People's decision whether or not to drive was unrelated to their BAC and to the number of drinks they reportedly had, and only marginally related to whether or not they felt drunk. Thirty percent of those who felt drunk still intended to drive. Although three-quarters of the respondents felt there is a driving and drinking problem in Israel, their knowledge about the effects of alcohol and the number of drinks they need to consume in order to get drunk reflected an alarming ignorance. The results demonstrate a dangerous trend in alcohol consumption that is not coupled with adequate specific knowledge about alcohol's effects.

Adolescent↗

PubMed1995

Thoracoscopic upper thoracic sympathectomy for primary palmar hyperhidrosis in children and adolescents.

After 20 years of experience with the "open" transaxillary approach, the authors are presently performing the thoracoscopic technique for upper thoracic sympathectomy in severe primary hyperhidrosis. During a period of 14 months, 23 operations were performed and 22 patients had immediate and permanent relief of palmar sweating. The immediate postoperative course was uneventful in all cases. Hospitalization was short, and all patients returned to school and full activity 3 to 5 days after operation. These initial results compare favorably to the "open" method and, pending further experience, are actually better in terms of less pain, early discharge, quicker return to normal activity, and a smaller, less conspicuous scar.

Adolescent↗

PubMed1993

Demographic and socioeconomic correlates of safety belt use.

This study analyzed the relationship between safety belt use rates--as measured by observational surveys at preselected sites--and demographic and socioeconomic characteristics--as reflected by the U.S. Census Bureau data for the sites. The results showed consistent and moderately high associations between observed safety belt use rates and socioeconomic status indicators, primarily home value. Once redundancies among variables were removed, other variables that contributed significantly to explaining differences between high- and low-belt use sites were the percentage of elderly people (55+ years old) and the mix of blue and white collar workers. Sites having high safety belt use rates had higher average home values, a higher percentage of elderly people, and a lower percentage of blue collar workers than sites having low use rates. Simple correlations with belt use rates were also obtained for race, marital status, presence of children in household, education, and income.

Adolescent↗

PubMed1992

Impact of court monitoring on the adjudication of driving while intoxicated (DWI).

Court monitoring of driving while intoxicated (DWI) cases is a labor-intensive effort conducted by over 300 concerned citizen groups across the United States. The present study assessed the impact of court monitoring by analyzing the difference in court dispositions (guilty, not guilty, and dismissed) and case outcomes (jail, fine, and license suspension) between monitored cases and non-monitored cases. The data base for this study consisted of all 9,137 DWI arrests made in the state of Maine in one calendar year. The results demonstrated that court monitoring is an effective tool in affecting the adjudication process. In the presence of court monitors the conviction rates of DWI offenders were higher and their case dismissal rates were lower than those of drivers not court-monitored. Furthermore, once convicted, the likelihood of a jail sentence was higher and the length of the jail sentence was longer for court-monitored DWI drivers than for non-monitored drivers. Monitoring impact was most pronounced for first-time offenders with BAC levels of .10-.11, and those refusing the BAC test.

Alcohol Drinking↗

PubMed1992

Identification of a new member of the steroid hormone receptor superfamily that is activated by a peroxisome proliferator and fatty acids.

We have identified a novel member of the steroid hormone receptor superfamily by cDNA cloning from a human osteosarcoma SAOS-2/B10 cell library. Sequence analysis predicts a protein of 441 amino acids, which includes the conserved amino acid residues characteristic of the DNA- and ligand-binding domains of nuclear receptors. Amino acid sequence alignment and transcriptional activation experiments revealed that the new protein is closely related to the mouse peroxisome proliferator activated receptor. The overall homology is 62%, and the highest similarity is seen in the DNA- and ligand-binding domains, 86% and 71%, respectively. Northern blot analysis showed that in mature rats, the receptor is highly expressed in heart, kidney, and lung as a transcript of approximately 3500 nucleotides. In human cells, the size of the mRNA is approximately 4000 nucleotides. Transcription assays using hybrid receptors consisting of the ligand-binding domain of the new protein and the DNA-binding domain of the glucocorticoid receptor showed weak stimulation by the peroxisome proliferator activator WY14643, suggesting a relationship to that receptor. Similar stimulation was observed with arachidonic and oleic acid (100-250 microM).

Amino Acid Sequence↗

PubMed1991

The visual and driving performance of monocular and binocular heavy-duty truck drivers.

This study compared the performance of 40 monocular and 40 binocular tractor-trailer drivers on measures of both visual and driving performance. On the visual measures, the mononuclear drivers were significantly deficient in contrast sensitivity, visual acuity under low illumination and glare, and binocular depth perception. They were not significantly deficient in static or dynamic visual acuity, visual field of individual eyes, or glare recovery. Driving measures of visual search, lane keeping, clearance judgment, gap judgment, hazard detection, and information recognition showed no differences between monocular and binocular drivers. Monocular drives were poorer than binocular drivers only in sign reading distance in both daytime and nighttime driving. This decrement correlated significantly with the binocular depth perception measure. There were large individual differences within each group for most of the visual and driving performance measures. It was concluded that monocular drivers have some significant reductions in selected visual capabilities and in certain driving functions dependent on these abilities, compared with binocular drivers. However, monocular drivers are not significantly worse than binocular drivers in the safety of most day-to-day driving functions. Implications of these findings and the large individual differences within each group are discussed.

Adult↗

PubMed1991

Visual requirements for safety and mobility of older drivers.

Efforts to assess visual deterioration with increasing age, coupled with new mechanisms proposed to limit the exposure of visually impaired drivers to driving risks, have emerged in response to the increase in older drivers. Visual functions discussed in this context include static acuity (photopic, mesopic, and in the presence of glare), dynamic visual acuity, visual field, contrast sensitivity, and motion perception. Exposure control mechanisms discussed include alternative periodic vision testing strategies, visual training, and environmental and vehicular modifications to accommodate the older driver. Finally, relevant research needs are addressed.

Aging↗

PubMed1990

Different pattern of alkaline phosphatase, osteopontin, and osteocalcin expression in developing rat bone visualized by in situ hybridization.

Alkaline phosphatase (AP), osteopontin (OP), and osteocalcin (OC) are expressed during osteoblastic differentiation. However, previous studies suggested differences in the timing and possibly the site of their expression. In this study we used in situ hybridization to follow the distribution of these osteoblastic markers during bone development. Frozen sections of neonatal rat long bones and calvariae were hybridized with 35S-labeled RNA probes complementary to the AP, OP, and OC mRNAs. Controls included sections hybridized with the sense (mRNA) probes or pretreated with RNase. Positive cells were identified in all areas of bone formation of the long bones and calvariae. Based on quantitative silver grain distribution and density, high levels of OP expression were present only in osteoblasts in close proximity to bone (one to two cell layers). OC expression, apparently at lower levels than OP, was also localized to osteoblasts in contact with bone. In contrast AP, which was expressed at lower levels than OP, was present in a large number of cells, including preosteoblasts that were many layers removed from the bone-forming surface. These findings are consistent with the asynchronous expression of phenotypically related genes and suggest that AP is an earlier differentiation marker than OP and OC during the formation of endochondral and membranous bone.

Alkaline Phosphatase↗

PubMed1989

Regulated expression of muscle-specific genes introduced into mouse embryonal stem cells: inverse correlation with DNA methylation.

Pluripotent embryonal stem cell lines (ES) were isolated from cultured normal mouse blastocysts. These cells retained their capacity to differentiate into a great variety of cell types in cell cultures or in tumors formed after subcutaneous injection of the cells into nude mice. A chimeric actin/globin gene containing about two-thirds of the rat skeletal muscle actin gene and 730 bp of its 5' flanking region fused to the 3' end of the human embryonic epsilon-globin gene, was inserted into a plasmid containing a neomycin resistance gene (neor) whose transcription is regulated by the SV40 early control elements. The prokaryotic vector DNA sequences of this plasmid (pAG-Neo) were deleted and the two linked genes were introduced into the ES cells by electroporation. G418-resistant clones were isolated, amplified and injected subcutaneously into nude mice. From the teratocarcinoma-like tumors which developed we isolated myogenic as well as nonmyogenic cell lines. In cell lines derived from three independent transfected ES clones, expression of the actin/globin gene was developmentally regulated in myogenic cells. In contrast, in a number of experiments in which the actin/globin gene or other muscle-specific genes were introduced into the ES cells without the removal of the pBR sequences, no expression could be detected at any stage. Moreover, in the differentiated lines derived from these clones, G418 resistance was lost, and no neor transcripts could be detected. Southern-blot analysis of MSPI- or HpaII-digested DNA revealed extensive methylation in the clones that did not express the foreign DNA, whereas no significant methylation of the inserted DNA was observed in clones which expressed the transfected genes. Examination of the DNA extracted from transgenic mice carrying the same actin/globin gene revealed an inverse correlation between methylation of the exogenous gene and its potential to be expressed in the transgenic strain. However, no tissue-specific differences in methylation, related to the tissue specificity of expression of the exogenous gene, could be detected in these experiments. These results suggest that the process of methylation reported here is causally related to constitutive inactivation of the exogenous genes.

Actins↗

PubMed1987

Interobserver reliability in the interpretation of computed tomographic scans of stroke patients.

Interobserver reliability in interpretation of computed tomographic images was studied by six senior neurologists who independently evaluated on a standardized Stroke Data Bank form the brain lesions of 17 patients. The results analyzed with kappa statistics yielded moderate to substantial agreement on most items of interest including the stroke pathology and anatomy. In general, the levels of agreement were as high as previously reported for the diagnosis of the mechanism of the stroke, and much higher than on many stroke history items and items of neurologic examination. Excellent agreement was obtained for the detection of infarcts and intracerebral hemorrhage, and substantial agreement was obtained on whether the computed tomographic images were normal or indicative of small deep infarcts, superficial and deep infarcts, and aneurysms. The level of agreement on anatomy of the lesions was best for the frontal, parietal, and temporal lobes, putamen, cerebellum, and subarachnoid space. Implications for clinical research and diagnosis are discussed.

Adult↗

PubMed1987

Reliability of the activities of daily living scale and its use in telephone interview.

Activities of daily living (ADL), a popular outcome assessment tool for studies of disabled populations, was evaluated for use in multicentered studies. The interobserver reliability of a modified Barthel Index of the ADL was evaluated on 18 stroke patients. Reliabilities between administrators of the ADL and between observers of the ADL administrations were r = .99 for total scores and r greater than .90 for most of the individual component items. The validity of ADL evaluation based on telephone interviews was demonstrated relative to ADL scores obtained on 72 patients in a direct test of their performance capabilities. The correlations between the performance-based ADL and the interview-based ADL were r greater than .97 for the total score and r greater than .85 for most of the individual items. The modified Barthel Index of the ADL is a reliable measure for assessing stable stroke patients, supporting its use in multicenter studies. In addition, the high validity observed in the telephone interview supports its use in longitudinal studies and large surveys where direct performance evaluation is not feasible or too costly.

Activities of Daily Living↗