Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Commuting”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2002

The impact of commuter war on military personnel.

BACKGROUND: The U.S. armed forces recently experienced a reduction in forces along with an increase in operational tempo. The Air Force and other branches supporting its mission share this common military burden and also experience a unique stressor. The Air Force has developed a military force that can fight by night and return home by day. The relatively new phenomenon of "commuter war" was especially evident during Operation Allied Force over Kosovo. METHODS: Military personnel (N = 540) participating in Operation Allied Force were administered a survey measuring morale, wellness behaviors, and work-family conflict. RESULTS: The deployment had adverse effects on wellness behaviors of permanent party and temporary duty assignment populations. Additionally, levels of morale and motivation varied between the two groups. Permanent party personnel also reported increased rates of work-family conflict. CONCLUSIONS: Commuter war affects wellness behaviors, morale, and work-family conflicts of military personnel.

Adult↗
PubMed2002

Selection, preparation, and characterization of commutable frozen human serum pools as potential secondary reference materials for lipid and apolipoprotein measurements: study within the framework of the Dutch project "Calibration 2000".

BACKGROUND: The Dutch project "Calibration 2000" aims at harmonization of laboratory results via calibration by development of matrix-based secondary reference materials. We considered the selection, preparation, and characterization of 34 potential reference materials (PRMs). METHODS: Sixteen PRMs were prepared either strictly according to the NCCLS C37-A protocol or in a less stringent and more convenient way. In addition, 18 commercial, so-called human serum-based calibrators or controls were purchased and tested. Lipoprotein integrity was evaluated by examining the physicochemical characteristics of the materials. Commutability of the PRMs was assessed in 86 Dutch clinical laboratories, using a multicenter split-patient-sample between-field-method (twin-study) design. Normalized residuals of the PRMs with respect to the patient regression lines were calculated; in addition, the extra contribution of each PRM to the total measurement uncertainty (CV(Netto)) was calculated. On the basis of these results, the most native PRM was selected to investigate its potential to reduce interlaboratory variation and to improve lipid and apolipoprotein standardization. RESULTS: In general, only the NCCLS C37-A-type materials displayed normalized residuals below the decision limit for commutability and had small CV(Netto) values ranging between 0 and 3.8%. This contrasts with the findings in regularly pooled frozen sera and lyophilized cryoprotected PRMs. In two subsequent external quality assessment surveys, the NCCLS type C37-A materials contributed to reducing the intermethod lipid and (apo)lipoprotein variation to approximately 2-4%. CONCLUSIONS: NCCLS C37-A materials have a strong potential as secondary reference materials, not only for cholesterol but also for HDL-cholesterol, LDL-cholesterol, triglyceride, and apolipoprotein measurements.

Apolipoprotein A-I↗
PubMed2002

Geographic patterns of pilot fatality rates in commuter and air taxi crashes.

BACKGROUND: Geographic information systems are widely used in studies of diseases. However, their value for aviation safety research has not been adequately explored. PURPOSE: This study examined the geographic patterns of pilot fatality rates in commuter and air taxi operations. METHODS: Crash data recorded by the National Transportation Safety Board under FAR Part 135 were used to create a digital map of all crash sites in the continental United States between 1983 and 1998. Fatality rates in crashes were calculated and then interpolated to create a contoured map of rates. A test of significance was performed using Monte Carlo simulations. High-, medium-, and low-rate areas were then compared for pilot characteristics, airplane characteristics, and crash circumstance. RESULTS: Of the 1094 commuter and air taxi crashes studied, 25% resulted in a pilot fatality. A large geographic area with a pilot fatality rate of > or = 36% extended through portions of Michigan, Indiana, and Illinois. A relatively low fatality rate (< 15%) prevailed over an area extending from Texas to northwest Georgia. Crashes in high-rate areas were significantly more likely than crashes elsewhere to have occurred at night and during instrument meteorological conditions. CONCLUSION: The geographic analysis revealed a distinctive pattern of pilot fatality rates from Part 135 crashes. Factors underlying the geographic pattern should be investigated, with particular attention to the great geographic variability of terrain and weather phenomena between the north and south regions of the United States.

Accidents, Aviation↗
PubMed1995

Factors related to pilot survival in helicopter commuter and air taxi crashes.

We examined factors related to pilot survival in 167 consecutive helicopter commuter and air taxi crashes that occurred during 1983-88. Case fatality rates and adjusted odds ratios from multivariate logistic regression models were determined using data from the National Transportation Safety Board (NTSB). During this 6-year period, 29 pilots-in-command died in 167 helicopter commuter and air taxi crashes, a case fatality rate of 17.4%. Factors significantly associated with increased risk of pilot fatality were aircraft fire [odds ratio (OR) 20.0, 95% confidence interval (CI) 4.6-86.8], not using shoulder harnesses (OR 9.2, 95% CI 2.2-37.3), and aircraft with two engines (OR 4.8, 95% CI 1.3-17.4). In addition, we present data regarding success and failure of emergency flotation devices. The results suggest that the likelihood of pilot survival in helicopter crashes could be greatly improved by preventing crash associated fires and promoting the usage of shoulder restraints.

Accidents, Aviation↗
PubMed1995

Determination of alpha-amylase activity: methods comparison and commutability study of several control materials.

Six different methods for alpha-amylase determination were compared by assaying human serum samples covering a wide range of alpha-amylase values. All the methods studied use as substrate a maltooligosaccharide with a chromophore group at the reducing end; some are chemically blocked at the nonreducing end. Intermethod comparison by regression and correspondence analyses showed significant differences for two methods. The commutability of 12 commercial control materials containing alpha-amylase was also assessed by the different methods in comparison with human serum specimens containing the pancreatic and salivary isoenzymes. We also studied the behavior of pancreatic and salivary materials prepared in our laboratory. Control materials with alpha-amylase of non-human origin were not commutable with the enzyme in human sera and should not be used for intermethod calibration.

Animals↗
PubMed1993

Changing population structure and commuting situation in Tokyo Megalopolis: a municipality-based analysis.

Census data was analyzed for 20 municipalities along the Tohoku Line in Tokyo Megalopolis to elucidate the changes in the population structure and the commuting situation in the last two decades. The major findings were: (1) the changing pattern of population structure markedly varied among the municipalities, and (2) the long-distance commuting workers have increased particularly among those 50 km or more from central Tokyo.

Adolescent↗
PubMed1993

Accurate enzyme activity measurements. Two decades of development in the commutability of enzyme quality control materials.

Commercial serum preparations are integral components of both internal and external quality control programs for enzyme activity measurements. However, properties of these materials may differ significantly from those of clinical specimens. Differences from clinical specimens may include the following: species origin of the enzyme; isoenzyme form(s); integrity of the molecular species; matrix of the solution; processes such as lyophilization; and addition of preservatives. There are also significant differences among methods measuring the activity of a single enzyme including a diversity of compounds that may serve as substrate(s); variable cofactor or metal supplementation; and differences in the substrate concentration(s), buffer substances, pH, and temperature. The measured response to each of these variations in assay technique may differ among these types of specimens. To be acceptable, quality control materials must have properties similar to those of clinical specimens. Thus, the concept of commutability that we originated and first applied to enzyme activity measurements remains useful, and its further application to the problem of "matrix effects" is reviewed here. Multivariate display techniques are applied to the specific examples of aspartate aminotransferase, alpha-amylase, and alkaline phosphatase to judge the commutability of quality control materials for these enzymes.

Bias↗
PubMed1988

Interdistrict migration in Great Britain 1980-81: a multistream model with a commuting option.

"In this paper an existing three-stream model of migration is adopted and extended to provide a first representation of district-district flows within Great Britain in 1980-81. The extended model incorporates an option for prospective migrants to choose commuting rather than a residential move after finding a new workplace, and employs a logistic function of distance in the regional or environmental stream where migrational opportunities tend not to be independent. Results are presented for the distribution of flows between local, regional, and national streams and for the geographical pattern of pushes and pulls in each."

Behavior↗
PubMed1996

Commutator filter: a novel technique for the identification of structures producing significant susceptibility inhomogeneities and its application to functional MRI.

A robust postprocessing method to detect regions of magnetic field change is presented. High resolution gradient echo data is acquired to create a complex baseline image. From this image, two low resolution images are obtained by applying a low pass filter on the magnitude image and the complex image, respectively. Subtraction of the magnitude of the filtered complex image from the filtered magnitude image gives a new image called a commutator image in which regions of susceptibility-induced field variation are greatly enhanced. Results on phantoms and applications to visualize paramagnetic venous blood vessels in the human brain are presented. The use of this technique on a 3D gradient echo data set represents a new approach to obtain an MR venogram. The application of this method to blood oxygenation level dependent (BOLD) functional brain MR imaging is demonstrated and the important role susceptibility plays in this model is verified.

Algorithms↗
PubMed1999

The roles of estimation and the commutativity principle in the development of third graders' mental multiplication.

In this training experiment, pretesting identified 36 third graders (mean age = 8 years 5 months, SD = 4 months) with negligible mastery of multiplication combinations involving factors from 3 to 9. Participants were randomly assigned to 2 groups, which practiced different subsets of combinations, and were then retested. The results were inconsistent with R. S. Siegler's (1988) proposal that item-specific computational practice is necessary to promote changes in error patterns and combination mastery. The results were consistent with the hypotheses that children devise increasingly flexible and accurate estimation strategies and use relational knowledge such as the commutativity principle to master combinations. Because even fast mental-arithmetic errors and correct responses may be due to strategies other than retrieval, researchers need to craft ways of distinguishing between retrieval and nonretrieval strategies.

Association Learning↗
PubMed1982

A reliable multichannel commutator for making electrical contact with conscious, freely moving rats.

A counterbalanced mercury swivel arrangement is often used to make connections between electrodes implanted in the brain of conscious laboratory animals and electronic equipment so that movement is not restricted. There are certain disadvantages associated with this system and an alternative is described which is based on a rhodium plated slip ring. The device is reliable, robust, causes minimal hindrance to the movement of the animal and causes virtually no interference noise to low level electrical signals. The slip ring based commutator has been incorporated into an automated system for making in vivo voltammetric recordings from conscious rats where currents of less than 100 nA are measured. Some of the results are shown.

Animals↗
PubMedDate not supplied

Lightweight, multi-contact, slip-ring commutator for recording and stimulation with small animals.

A slip-ring commutator which can be used to electrically stimulate and/or record from the brains of small, unrestrained animals is described. In addition to providing 4 to 10 independent electrical contacts, featues of this model include its small size, low torque characteristics, low rate of contact oxidation, and minimal noise generated at the brush-ring surface. The compactness and light weight of this unit permit it to be suspended from a counterweighted boom assembly, thus providing additional freedom for vertical movement.

Animals↗
PubMed2004

Boarding and alighting injury experience with different station platform and car entranceway designs on US commuter railroads.

Commuter railroad systems in the US employ three combinations of station platforms and car entranceways. These are high-level platforms with remotely controlled doors and level entranceway (HL-RC), low-level platforms (just above the rail) with steps and remotely controlled doors (LL-RC), and a mixture of the two platform types with a correspondingly more complex, partly manual, door and entranceway arrangement (ML-MO). Much controversy exists over which type of platform/entranceway is better. This seemingly small feature significantly impacts many performance characteristics of these systems, including cost, speed, and boarding and alighting accidents. Northeastern systems are generally moving toward the mixed platform design or all high-level platforms, while systems elsewhere are generally selecting the low-level design. Data on actual accident experience for 1995-2000 are analyzed to determine the effect of platform/entranceway type on passenger and employee injuries. Passenger injury rates on systems with the HL-RC design are lowest, with LL-RC systems next, and ML-MO systems having the highest rates. Employee injury rates are the least on LL-RC systems, but higher on ML-MO and HL-RC systems. Systems with a mixture of high and low platforms (ML-MO) experience a higher overall (combined passenger and employee) injury rate than the other two designs. The implications of these results for both the modernization of existing systems and the design of new systems, in the US and abroad, are discussed.

Accidents, Occupational↗
PubMed1998

Ottawa-Carleton commuter cyclist on- and off-road incident rates.

This analysis overcomes the known limitations of police and emergency room bicycle accident databases through use of a survey that asked cyclists to indicate their accident history as well as their regular commute route to work or school. By relating the route information of the 1604 respondents (52.5% of the distributed questionnaires) to facility attributes in a Geographic Information System, defensible estimates of travel exposure on roads, off-road paths and sidewalks were developed. The relative rates of collisions on the three different facility types were not statistically different from 1.0. The relative rates for falls and injuries suggest it is safest to cycle on-road followed by off-road paths and trails, and finally least safe on sidewalks. While there were no major injuries reported on sidewalks, the relative rate for these events on paths was greater than the rate for roads. The absolute event rates per bicycle kilometre were found to be between 10 and 41 times higher than similar rates for automobile travel. Results suggest a need to discourage sidewalk cycling, and to further investigate the safety of off-road paths/trails. The analysis also demonstrates the need for bicycle travel exposure information and the use of more than just collision databases for bicycle safety analysis.

Accident Prevention↗
PubMed2001

Miniature motorized microdrive and commutator system for chronic neural recording in small animals.

The use of chronically implanted electrodes for neural recordings in small, freely behaving animals poses several unique technical challenges. Because of the need for an extremely lightweight apparatus, chronic recording technology has been limited to manually operated microdrives, despite the advantage of motorized manipulators for positioning electrodes. Here we describe a motorized, miniature chronically implantable microdrive for independently positioning three electrodes in the brain. The electrodes are controlled remotely, avoiding the need to disturb the animal during electrode positioning. The microdrive is approximately 6 mm in diameter, 17 mm high and weighs only 1.5 g, including the headstage preamplifier. Use of the motorized microdrive has produced a ten-fold increase in our data yield compared to those experiments done using a manually operated drive. In addition, we are able to record from multiple single neurons in the behaving animal with signal quality comparable to that seen in a head-fixed anesthetized animal. We also describe a motorized commutator that actively tracks animal rotation based on a measurement of torque in the tether.

Action Potentials↗
PubMed2003

Commuting to school: are children who walk more physically active?

BACKGROUND: The journey to school is an opportunity for increasing children's daily physical activity. However, the contribution that active commuting to school makes to overall physical activity is unknown. This study used objective measurement to investigate the physical activity patterns of children by mode of travel to school. METHODS: Primary-school children wore an accelerometer programmed to record minute-by-minute physical activity for 7 days and completed a brief questionnaire describing their usual travel to school. The total volume of physical activity and the time spent in activity of at least moderate intensity, as recorded by the accelerometer, was estimated for weekdays and the weekend, and groups of children were compared by mode of transport to school. Data were collected in May/June 2002. RESULTS: Of the 114 children (59 boys, 55 girls; aged 10.4+/-0.8 years) who took part in the study, those who walked to school (65%) were significantly more active than those who traveled by car (712.0+/-206.7 vs 629.9+/-207.2 accelerometer counts per minute, p=0.05). Analysis by gender indicated that the major differences in physical activity between travel groups were seen only in boys. Hourly activity patterns demonstrated that boys who walked to school were more active after school and throughout the evening than were car users. CONCLUSIONS: In boys, walking to school was associated with higher physical activity after school and during the evening. Active transport may contribute to a more physically active profile, at least for boys, supporting walk-to-school initiatives to increase children's physical activity.

Child↗
PubMedDate not supplied

Urban commuter exposure to particle matter and carbon monoxide inside an automobile.

In-vehicle exposures to different sizes of particles and carbon monoxide (CO) were determined while driving along a standardized route under a variety of traffic conditions in Kuopio, Finland during the 12-month period from January to December 1995. Arithmetic means of in-vehicle exposures during the morning rush hours were 5.7 parts per million (ppm) (geometric mean, GM = 3.1 ppm, geometric standard deviation, GSD = 1.7) for CO, 107 #/cm3 (GM = 75 #/cm3, GSD = 1.9) for fine particles (optical equivalent particle size range 0.3-1 micron) and 0.9 #/cm3 (GM = 0.6 #/cm3, GSD = 2.1) for coarse particles (optical equivalent particle size range 1-10 microns). Fine particles and CO behaved similarly in different weather and traffic conditions, while the behavior of coarse particles was usually different, and often opposite. The driving conditions that affected the passengers' exposures to CO and fine particles were the time of day (morning vs. afternoon) and average speed (decreasing). The meteorological parameters that affected the passengers' exposures to CO and fine particles were wind speed (decreasing) and relative humidity (increasing). Wind speed, relative humidity and driving speed all had opposite effects on the exposure levels to fine vs. coarse particles. Added exposures (due to commuting on top of the background levels) to CO and fine particles were considerably higher in the morning vs. the afternoon runs and also higher in the slower vs. the faster runs.

Air Pollution, Indoor↗