Science.gov

Sample records for actual distance traveled

  1. Visual estimation of travel distance during walking.

    PubMed

    Lappe, Markus; Frenz, Harald

    2009-12-01

    The optic flow generated in the eyes during self-motion provides an important control signal for direction and speed of self-motion, and can be used to track the distance that has been traveled. The use of vision for these behavioral tasks can be studied in isolation in virtual reality setups, in which self-motion is merely simulated, and in which the visual motion can be controlled independently of other sensory cues. In such experiments it was found that the estimation of the travel distance of a simulated movement shows characteristic errors, sometimes overestimating and sometimes underestimating the true travel distance. These errors can be explained by a leaky path integration model. To test whether this model also holds for actual self-motion in the real world we studied walking distance perception in an open field with tasks similar to those previously used in virtual environments. We show that similar errors occur in the estimation of travel distance in the real world as in virtual environment, and that they are consistent with the leaky integration model.

  2. Travel distance and mass gain in wintering blackbirds.

    PubMed

    Cresswell

    1999-11-01

    Birds that range over a large area will have a greater mass-dependent risk of predation than more sedentary birds. Birds that travel more may then reduce winter mass gain to compensate for the increased predation risk that greater travelling entails. I tested whether European blackbirds, Turdus merula, that travelled more in winter had a lower mass than more sedentary birds, independently of any confounding effects of food supply on both ranging behaviour and mass gain. I measured change in winter mass and amount of food eaten in conjunction with the distance that blackbirds travelled to a randomly sited mobile feeder. Blackbirds that travelled shorter distances (per trip and in total) and less often to the feeder had the highest mass midwinter relative to their spring mass. Blackbirds with a higher mean mass midwinter also travelled, on average, shorter distances to the feeder. The distance an individual blackbird travelled to the feeder at any one time was probably independent of the state of its daily energy reserves (how much of its daily total mass gain it had achieved at that point). The relationship between distance travelled and mass was probably independent of food supply because distances actually increased at the end of the winter and the amount of food eaten per individual changed little. More mobile blackbirds were therefore likely to have compensated for any increases in predation risk associated with their greater ranges by decreasing winter mass gain, but will have had an increased risk of starvation because of their lower mass. Copyright 1999 The Association for the Study of Animal Behaviour.

  3. Absolute travel distance from optic flow.

    PubMed

    Frenz, Harald; Lappe, Markus

    2005-06-01

    Optic flow fields provide rich information about the observer's self-motion. Besides estimation of the direction of self-motion human observers are also able to discriminate the travel distances of two self-motion simulations. Recent studies have shown that observers estimate the simulated ego velocity of the self-motion simulation and integrate it over time. Thus, observers use a 3-D percept of the ego motion through the environment. In the present work we ask if human observers are able to use this 3-D percept of the motion simulation to build up an internal representation of travel distance and indicate it in a static scene. We visually simulated self-motion in different virtual environments and asked subjects to indicate the perceived distances in terms of static virtual intervals on the ground. The results show that human observers possess a static distance gauge, but that they undershoot the travel distances for short motion simulations. In further experiments we changed the modality of the distance indication but the undershoot in distance estimation remained. This suggests that the undershoot is linked to the perception of the optic flow field.

  4. Using multiple travel paths to estimate daily travel distance in arboreal, group-living primates.

    PubMed

    Steel, Ruth Irene

    2015-01-01

    Primate field studies often estimate daily travel distance (DTD) in order to estimate energy expenditure and/or test foraging hypotheses. In group-living species, the center of mass (CM) method is traditionally used to measure DTD; a point is marked at the group's perceived center of mass at a set time interval or upon each move, and the distance between consecutive points is measured and summed. However, for groups using multiple travel paths, the CM method potentially creates a central path that is shorter than the individual paths and/or traverses unused areas. These problems may compromise tests of foraging hypotheses, since distance and energy expenditure could be underestimated. To better understand the magnitude of these potential biases, I designed and tested the multiple travel paths (MTP) method, in which DTD was calculated by recording all travel paths taken by the group's members, weighting each path's distance based on its proportional use by the group, and summing the weighted distances. To compare the MTP and CM methods, DTD was calculated using both methods in three groups of Udzungwa red colobus monkeys (Procolobus gordonorum; group size 30-43) for a random sample of 30 days between May 2009 and March 2010. Compared to the CM method, the MTP method provided significantly longer estimates of DTD that were more representative of the actual distance traveled and the areas used by a group. The MTP method is more time-intensive and requires multiple observers compared to the CM method. However, it provides greater accuracy for testing ecological and foraging models.

  5. Travel distance estimation from visual motion by leaky path integration.

    PubMed

    Lappe, Markus; Jenkin, Michael; Harris, Laurence R

    2007-06-01

    Visual motion can be a cue to travel distance when the motion signals are integrated. Distance estimates from visually simulated self-motion are imprecise, however. Previous work in our labs has given conflicting results on the imprecision: experiments by Frenz and Lappe had suggested a general underestimation of travel distance, while results from Redlick, Jenkin and Harris had shown an overestimation of travel distance. Here we describe a collaborative study that resolves the conflict by tracing it to differences in the tasks given to the subjects. With an identical set of subjects and identical visual motion simulation we show that underestimation of travel distance occurs when the task involves a judgment of distance from the starting position, and that overestimation of travel distance occurs when the task requires a judgment of the remaining distance to a particular target position. We present a leaky integrator model that explains both effects with a single mechanism. In this leaky integrator model we introduce the idea that, depending on the task, either the distance from start, or the distance to target is used as a state variable. The state variable is updated during the movement by integration over the space covered by the movement, rather than over time. In this model, travel distance mis-estimation occurs because the integration leaks and because the transformation of visual motion to travel distance involves a gain factor. Mis-estimates in both tasks can be explained with the same leak rate and gain in both conditions. Our results thus suggest that observers do not simply integrate traveled distance and then relate it to the task. Instead, the internally represented variable is either distance from the origin or distance to the goal, whichever is relevant.

  6. 41 CFR 302-10.101 - Must I furnish actual odometer readings on the travel claim?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... odometer readings on the travel claim? 302-10.101 Section 302-10.101 Public Contracts and Property... § 302-10.101 Must I furnish actual odometer readings on the travel claim? No, you do not need to furnish odometer readings on the travel claim but you must indicate the total miles traveled. Any deviation...

  7. 41 CFR 302-10.101 - Must I furnish actual odometer readings on the travel claim?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... odometer readings on the travel claim? 302-10.101 Section 302-10.101 Public Contracts and Property... § 302-10.101 Must I furnish actual odometer readings on the travel claim? No, you do not need to furnish odometer readings on the travel claim but you must indicate the total miles traveled. Any deviation...

  8. 41 CFR 302-10.101 - Must I furnish actual odometer readings on the travel claim?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... odometer readings on the travel claim? 302-10.101 Section 302-10.101 Public Contracts and Property... § 302-10.101 Must I furnish actual odometer readings on the travel claim? No, you do not need to furnish odometer readings on the travel claim but you must indicate the total miles traveled. Any deviation...

  9. 41 CFR 302-10.101 - Must I furnish actual odometer readings on the travel claim?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... odometer readings on the travel claim? 302-10.101 Section 302-10.101 Public Contracts and Property... § 302-10.101 Must I furnish actual odometer readings on the travel claim? No, you do not need to furnish odometer readings on the travel claim but you must indicate the total miles traveled. Any deviation...

  10. 41 CFR 302-10.101 - Must I furnish actual odometer readings on the travel claim?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... odometer readings on the travel claim? 302-10.101 Section 302-10.101 Public Contracts and Property... § 302-10.101 Must I furnish actual odometer readings on the travel claim? No, you do not need to furnish odometer readings on the travel claim but you must indicate the total miles traveled. Any deviation...

  11. Horizontal Distance Travelled by a Mobile Experiencing a Quadratic Drag Force: Normalized Distance and Parametrization

    ERIC Educational Resources Information Center

    Vial, Alexandre

    2007-01-01

    We investigate the problem of the horizontal distance travelled by a mobile experiencing a quadratic drag force. We show that by introducing a normalized distance, the problem can be greatly simplified. In order to parametrize this distance, we use the Pearson VII function, and we find that the optimal launch angle as a function of the initial…

  12. 41 CFR 301-10.302 - How do I determine distance measurements for my travel?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... distance measurements for my travel? 301-10.302 Section 301-10.302 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES ALLOWABLE TRAVEL EXPENSES 10... my travel? If you travel by The distance between your origin and destination is Privately...

  13. Beyond Neighborhood Food Environments: Distance Traveled to Food Establishments in 5 US Cities, 2009–2011

    PubMed Central

    Han, Bing; Cohen, Deborah A.

    2015-01-01

    Introduction Accurate conceptualizations of neighborhood environments are important in the design of policies and programs aiming to improve access to healthy food. Neighborhood environments are often defined by administrative units or buffers around points of interest. An individual may eat and shop for food within or outside these areas, which may not reflect accessibility of food establishments. This article examines the relevance of different definitions of food environments. Methods We collected data on trips to food establishments using a 1-week food and travel diary and global positioning system devices. Spatial-temporal clustering methods were applied to identify homes and food establishments visited by study participants. Results We identified 513 visits to food establishments (sit-down restaurants, fast-food/convenience stores, malls or stores, groceries/supermarkets) by 135 participants in 5 US cities. The average distance between the food establishments and homes was 2.6 miles (standard deviation, 3.7 miles). Only 34% of the visited food establishments were within participants’ neighborhood census tract. Buffers of 1 or 2 miles around the home covered 55% to 65% of visited food establishments. There was a significant difference in the mean distances to food establishments types (P = .008). On average, participants traveled the longest distances to restaurants and the shortest distances to groceries/supermarkets. Conclusion Many definitions of the neighborhood food environment are misaligned with individual travel patterns, which may help explain the mixed findings in studies of neighborhood food environments. Neighborhood environments defined by actual travel activity may provide more insight on how the food environment influences dietary and food shopping choices. PMID:26247426

  14. How do dynamic cellular signals travel long distances?

    PubMed

    Nussinov, Ruth

    2012-01-01

    Communication is essential. It is vital between cells in multi-cellular organisms, and within cells. A signaling molecule binds to a receptor protein, and initiates a cascade of dynamic events. Signaling is a multistep pathway, which allows signal amplification: if some of the molecules in a pathway transmit the signal to multiple molecules, the result can be a large number of activated molecules across the cell and multiple reactions. That is how a small number of extracellular signaling molecules can produce a major cellular response. The pathway can relay signals from the extracellular space to the nucleus. How do signals travel efficiently over long-distances across the cell? Here we argue that evolution has utilized three properties: a modular functional organization of the cellular network; sequences in some key regions of proteins, such as linkers or loops, which were pre-encoded by evolution to facilitate signaling among domains; and compact interactions between proteins which is achieved via conformational disorder.

  15. Humans can use optic flow to estimate distance of travel.

    PubMed

    Redlick, F P; Jenkin, M; Harris, L R

    2001-01-15

    We demonstrate that humans can use optic flow to estimate distance travelled when appropriate scaling information is provided. Eleven subjects were presented with visual targets in a virtual corridor. They were then provided with optic flow compatible with movement along the corridor and asked to indicate when they had reached the previously presented target position. Performance depended on the movement profile: for accelerations above 0.1 m/s2 performance was accurate. Slower optic-flow acceleration resulted in an overestimation of motion which was most pronounced for constant velocity motion when the overestimation reached 170%. The results are discussed in terms of the usual synergy between multiple sensory cues to motion and the factors that might contribute to such a pronounced miscalibration between optic flow and the resulting perception of motion.

  16. Factors Associated with Distance and Time Traveled to Cleft and Craniofacial Care

    PubMed Central

    Cassell, Cynthia H.; Krohmer, Anne; Mendez, Dara D.; Lee, Kyung A.; Strauss, Ronald P.; Meyer, Robert E.

    2015-01-01

    BACKGROUND Information on travel distance and time to care for children with birth defects is lacking. We examined factors associated with travel distance and time to cleft care among children with orofacial clefts. METHODS In 2006, a mail/phone survey was administered in English and Spanish to all resident mothers of children with orofacial clefts born 2001 to 2004 and identified by the North Carolina birth defects registry. We analyzed one-way travel distance and time and the extent to which taking a child to care was a problem. We used multivariable logistic regression to examine the association between selected sociodemographic factors and travel distance (≤60 miles and >60 miles) and time (≤60 min and >60 min) to cleft care. RESULTS Of 475 eligible participants, 51.6% (n = 245) responded. Of the respondents, 97.1% (n = 238) were the child’s biological mother. Approximately 83% (n = 204) of respondents were non-Hispanic White; 33.3% (n = 81) were college educated; and 50.0% (n = 115) had private health insurance. One-way mean and median travel distances were 80 and 50 miles, respectively (range, 0–1058 miles). One-way mean and median travel times were 92 and 60 min, respectively (range, 5 min to 8 hr). After adjusting for selected sociodemographics, travel distance varied significantly by maternal education, child’s age, and cleft type. Travel time varied significantly by child’s age. Approximately 67% (n = 162) reported taking their child to receive care was not a problem. CONCLUSION Approximately 48% of respondents traveled > 1 hr to receive cleft care. Increasing access to care may be important for improving health outcomes among this population. PMID:24039055

  17. Interplay between Velocity and Travel Distance of Kinesin-based Transport in the Presence of Tau

    NASA Astrophysics Data System (ADS)

    Xu, Jing; King, Stephen; Lapierre-Landry, Maryse; Nemec, Brian

    2014-03-01

    Although the disease-relevant microtubule-associated protein tau is known to severely inhibit kinesin-based transport in vitro, potential mechanisms for reversing this detrimental effect to maintain healthy transport in cells remain unknown. Here we report the unambiguous up-regulation of multiple-kinesin travel distance despite the presence of tau, via decreased single-kinesin velocity. Intriguingly, the presence of tau also modestly reduced velocity in multiple-kinesin transport. Our stochastic simulations indicate that the tau-mediated reduction in single-kinesin travel is sufficient for the observed reduction in multiple-kinesin velocity. Taken together, our observations suggest that single-kinesin velocity is a promising experimental handle for tuning the effect of tau on multiple-kinesin travel distance, and uncover a previously unexplored role of tau for inhibiting multiple-kinesin velocity via reducing single-kinesin travel distance. This work was supported in part by NIH grant NS048501 to SJK.

  18. Interplay between Velocity and Travel Distance of Kinesin-based Transport in the Presence of Tau

    PubMed Central

    Xu, Jing; King, Stephen J.; Lapierre-Landry, Maryse; Nemec, Brian

    2013-01-01

    Although the disease-relevant microtubule-associated protein tau is known to severely inhibit kinesin-based transport in vitro, the potential mechanisms for reversing this detrimental effect to maintain healthy transport in cells remain unknown. Here we report the unambiguous upregulation of multiple-kinesin travel distance despite the presence of tau, via decreased single-kinesin velocity. Interestingly, the presence of tau also modestly reduced cargo velocity in multiple-kinesin transport, and our stochastic simulations indicate that the tau-mediated reduction in single-kinesin travel underlies this observation. Taken together, our observations highlight a nontrivial interplay between velocity and travel distance for kinesin transport, and suggest that single-kinesin velocity is a promising experimental handle for tuning the effect of tau on multiple-kinesin travel distance. PMID:24268156

  19. Pacing strategy in simulated cycle time-trials is based on perceived rather than actual distance.

    PubMed

    Nikolopoulos, V; Arkinstall, M J; Hawley, J A

    2001-06-01

    This study determined the pacing strategies and performance responses of six well-trained cyclists/triathletes (peak O2 uptake 66.4+/-3.7 ml x kg(-1) x min(-1), mean+/-SD) during seven simulated time-trials (TT) conducted on a wind-braked cycle ergometer. All subjects first performed a 40 km familiarisation ride (TT1). They were then informed they would be riding a further four 40 km TT for the purpose of a reliability study. Instead, the actual distances ridden for the next three TT were a random order of 34 (TT2), 40 (TT3) and 46 km (TT4). The only feedback given to subjects during TT1-4 was the percentage distance of that ride remaining. During a further 40 km TT (TT5) subjects were allowed to view their heart rate (HR) responses throughout the ride. Despite the significantly different performance times across the three distances (47:23+/-4:23 vs 55:57+/-3:24 vs 65:41+/-3:56 min for the 34, 40 and 46 km respectively, P<0.001), average power output (296+/-48 vs 294+/-48 vs 286+/-40 W) and HR (173+/-11 vs 174+/-12 vs 173+/-12 beats x min(-1)) were similar. The true nature of the first part of the study was then revealed to subjects who subsequently completed an additional 34 km and 46 km TT TT6-7) in which the actual and perceived distance ridden was the same. Power output and HR responses were similar for both unknown (TT2 and TT6) and known (TT4 and TT7) rides for both distances: 296+/-48 vs 300+/-55 W and 173+/-11 vs 177+/-11 beats x min(-1) (34 km) and 286+/-40 vs 273+/-42 W and 173+/-12 vs 174+/-12 beats x min(-1) (46 km). In conclusion, well-trained cyclists rode at similar power outputs and HR during time trials they perceived to be the same distance, but which varied in actual distance from 34 to 46 km.

  20. Selective functionalization of carbon nanotubes based upon distance traveled

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

    2010-01-01

    Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H.sub.2 or NH.sub.3 or NF.sub.3 or F.sub.2 or CF.sub.4 or C.sub.nH.sub.m) is irradiated to provide a cold plasma of selected target particles, such as atomic H or F, in a first chamber. The target particles are directed toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. The predominant species that are deposited on the CNT array vary with the distance d measured along a path from the precursor gas to the CNT array; two or three different predominant species can be deposited on a CNT array for distances d=d1 and d=d2>d1 and d=d3>d2.

  1. Travel distance and the use of inpatient care among patients with schizophrenia.

    PubMed

    Tseng, Kuan-Chiao; Hemenway, David; Kawachi, Ichiro; Subramanian, S V; Chen, Wei J

    2008-09-01

    This study examines the variations in the use of inpatient care that can be explained by travel distance among patients with schizophrenia living in Taiwan. Data were drawn from the Psychiatric Inpatient Medical Claims Database. We used mediation analysis and multilevel analysis to identify associations. Travel distance did not significantly account for lower readmission rates after an index admission, but significantly explained the longer length of stay of an index admission by 9.3 days (P<0.001, 85% of variation) between remote and non-remote regions. Policies are discussed aimed at reducing the impact of travel distance on rural mental health care through inter-disciplinary collaboration and telepsychiatry. PMID:18512144

  2. Data Processing Procedures and Methodology for Estimating Trip Distances for the 1995 American Travel Survey (ATS)

    SciTech Connect

    Hwang, H.-L.; Rollow, J.

    2000-05-01

    The 1995 American Travel Survey (ATS) collected information from approximately 80,000 U.S. households about their long distance travel (one-way trips of 100 miles or more) during the year of 1995. It is the most comprehensive survey of where, why, and how U.S. residents travel since 1977. ATS is a joint effort by the U.S. Department of Transportation (DOT) Bureau of Transportation Statistics (BTS) and the U.S. Department of Commerce Bureau of Census (Census); BTS provided the funding and supervision of the project, and Census selected the samples, conducted interviews, and processed the data. This report documents the technical support for the ATS provided by the Center for Transportation Analysis (CTA) in Oak Ridge National Laboratory (ORNL), which included the estimation of trip distances as well as data quality editing and checking of variables required for the distance calculations.

  3. 41 CFR 301-10.302 - How do I determine distance measurements for my travel?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the actual miles driven as determined from odometer readings. Privately owned aircraft As determined... cruising speed of the aircraft to determine distance. You must convert nautical miles to statute or...

  4. 41 CFR 301-10.302 - How do I determine distance measurements for my travel?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the actual miles driven as determined from odometer readings. Privately owned aircraft As determined... cruising speed of the aircraft to determine distance. You must convert nautical miles to statute or...

  5. 41 CFR 301-10.302 - How do I determine distance measurements for my travel?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the actual miles driven as determined from odometer readings. Privately owned aircraft As determined... cruising speed of the aircraft to determine distance. You must convert nautical miles to statute or...

  6. Catchment Power and the Joint Distribution of Elevation and Travel Distance to the Outlet

    NASA Astrophysics Data System (ADS)

    Sklar, L. S.; Riebe, C. S.; Bellugi, D. G.; Lukens, C. E.; Noll, C.

    2014-12-01

    The delivery of water, sediment and solutes by catchments is influenced by the distribution of source elevations and their travel distances to the outlet. For example, elevation affects the magnitude and phase of precipitation, as well as the climatic factors that govern rock weathering, which influences the particle size and production rate of sediment from slopes. Travel distance, in turn, affects the timing of flood peaks at the outlet and the degree of sediment size reduction by wear, which affect particle size distributions at the outlet. The distributions of elevation and travel distance have been studied extensively but separately, as the hypsometric curve and width function. Yet a catchment can be considered as a collection of points, each with paired values of elevation and travel distance. We refer to the joint distribution of these two fundamental catchment attributes as "catchment power," recognizing that the ratio of elevation to travel distance is proportional to the average rate of loss of the potential energy provided by source elevation, as water or sediment travel to the outlet. We explore patterns in catchment power across a suite of catchments spanning a range of relief, drainage area and channel network geometry. We also develop an empirical algorithm for generating synthetic catchment power distributions, which can be parameterized with data from natural catchments, and used to explore the effects of varying the shape of the distribution on fluxes of water, sediment, isotopes and other landscape products passing through catchment outlets. Ultimately, our goal is to understand how catchment power distributions arise from the branching properties of networks and the relief structure of landscapes. This new way of quantifying catchment geometry may provide a fresh perspective on problems of both practical and theoretical interest.

  7. 41 CFR 302-3.220 - May my family and I travel to another U.S. location (other than from my actual place of residence...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... travel to another U.S. location (other than from my actual place of residence) under my tour renewal agreement? 302-3.220 Section 302-3.220 Public Contracts and Property Management Federal Travel Regulation... Transfers Overseas Tour Renewal Agreement § 302-3.220 May my family and I travel to another U.S....

  8. 41 CFR 302-3.220 - May my family and I travel to another U.S. location (other than from my actual place of residence...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... travel to another U.S. location (other than from my actual place of residence) under my tour renewal agreement? 302-3.220 Section 302-3.220 Public Contracts and Property Management Federal Travel Regulation... Transfers Overseas Tour Renewal Agreement § 302-3.220 May my family and I travel to another U.S....

  9. 41 CFR 302-3.221 - If I travel to another place in the U.S. (other than my actual place of residence) am I required...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false If I travel to another place in the U.S. (other than my actual place of residence) am I required to spend time at my actual... Management Federal Travel Regulation System RELOCATION ALLOWANCES RELOCATION ALLOWANCES...

  10. 41 CFR 302-3.221 - If I travel to another place in the U.S. (other than my actual place of residence) am I required...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false If I travel to another place in the U.S. (other than my actual place of residence) am I required to spend time at my actual... Management Federal Travel Regulation System RELOCATION ALLOWANCES RELOCATION ALLOWANCES...

  11. 41 CFR 302-3.221 - If I travel to another place in the U.S. (other than my actual place of residence) am I required...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false If I travel to another place in the U.S. (other than my actual place of residence) am I required to spend time at my actual... Management Federal Travel Regulation System RELOCATION ALLOWANCES RELOCATION ALLOWANCES...

  12. 41 CFR 302-3.221 - If I travel to another place in the U.S. (other than my actual place of residence) am I required...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true If I travel to another place in the U.S. (other than my actual place of residence) am I required to spend time at my actual... Management Federal Travel Regulation System RELOCATION ALLOWANCES RELOCATION ALLOWANCES...

  13. 41 CFR 302-3.221 - If I travel to another place in the U.S. (other than my actual place of residence) am I required...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false If I travel to another place in the U.S. (other than my actual place of residence) am I required to spend time at my actual... Management Federal Travel Regulation System RELOCATION ALLOWANCES RELOCATION ALLOWANCES...

  14. 41 CFR 302-3.217 - Will my family or I receive per diem for en route travel from my post of duty to my actual place...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... receive per diem for en route travel from my post of duty to my actual place of residence in the U.S.? 302... Overseas Tour Renewal Agreement § 302-3.217 Will my family or I receive per diem for en route travel from... diem for en route travel from your post of duty to your actual place of residence in the U.S....

  15. NOTE ON TRAVEL TIME SHIFTS DUE TO AMPLITUDE MODULATION IN TIME-DISTANCE HELIOSEISMOLOGY MEASUREMENTS

    SciTech Connect

    Nigam, R.; Kosovichev, A. G. E-mail: sasha@quake.stanford.ed

    2010-01-10

    Correct interpretation of acoustic travel times measured by time-distance helioseismology is essential to get an accurate understanding of the solar properties that are inferred from them. It has long been observed that sunspots suppress p-mode amplitude, but its implications on travel times have not been fully investigated so far. It has been found in test measurements using a 'masking' procedure, in which the solar Doppler signal in a localized quiet region of the Sun is artificially suppressed by a spatial function, and using numerical simulations that the amplitude modulations in combination with the phase-speed filtering may cause systematic shifts of acoustic travel times. To understand the properties of this procedure, we derive an analytical expression for the cross-covariance of a signal that has been modulated locally by a spatial function that has azimuthal symmetry and then filtered by a phase-speed filter typically used in time-distance helioseismology. Comparing this expression to the Gabor wavelet fitting formula without this effect, we find that there is a shift in the travel times that is introduced by the amplitude modulation. The analytical model presented in this paper can be useful also for interpretation of travel time measurements for the non-uniform distribution of oscillation amplitude due to observational effects.

  16. Transportation statistics annual report 1998: Long-distance travel and freight

    SciTech Connect

    Fenn, M.

    1998-12-01

    This is the fifth annual report prepared by the Bureau of Transportation Statistics (BTS). As in prior years, the report brings together under one cover information about how the transportation system is used, how well it works, its economic contributions and costs, and its unintended consequences for safety, energy import dependency, and the environment. This year`s report also contains a detailed analysis of long-distance passenger travel and freight activity, drawing on the American Travel Survey and the Commodity Flow Survey conducted by BTS in cooperation with the US Census Bureau.

  17. 41 CFR 301-10.302 - How do I determine distance measurements for my travel?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false How do I determine... the actual miles driven as determined from odometer readings. Privately owned aircraft As determined... cruising speed of the aircraft to determine distance....

  18. SU-E-T-545: MLC Distance Travelled as a Predictor for Motor Failure

    SciTech Connect

    Stathakis, S; Defoor, D; Linden, P; Kirby, N; Papanikolaou, N; Mavroidis, P

    2015-06-15

    Purpose: To study the frequency of Multi-Leaf Collimator (MLC) leaf failures, investigate methods to predict them and reduce linac downtime. Methods: A Varian HD120 MLC was used in our study. The hyperterminal MLC errors logged from 06/2012 to 12/2014 were collected. Along with the hyperterminal errors, the MLC motor changes and all other MLC interventions by the linear accelerator engineer were recorded. The MLC dynalog files were also recorded on a daily basis for each treatment and during linac QA. The dynalog files were analyzed to calculate root mean square errors (RMS) and cumulative MLC travel distance per motor. An in-house MatLab code was used to analyze all dynalog files, record RMS errors and calculate the distance each MLC traveled per day. Results: A total of 269 interventions were recorded over a period of 18 months. Of these, 146 included MLC motor leaf change, 39 T-nut replacements, and 84 MLC cleaning sessions. Leaves close to the middle of each side required the most maintenance. In the A bank, leaves A27 to A40 recorded 73% of all interventions, while the same leaves in the B bank counted for 52% of the interventions. On average, leaves in the middle of the bank had their motors changed approximately every 1500m of travel. Finally, it was found that the number of RMS errors increased prior to an MLC motor change. Conclusion: An MLC dynalog file analysis software was developed that can be used to log daily MLC usage. Our eighteen-month data analysis showed that there is a correlation between the distance an MLC travels, the RMS and the life of the MLC motor. We plan to use this tool to predict MLC motor failures and with proper and timely intervention, reduce the downtime of the linac during clinical hours.

  19. Influence of water chemistry and travel distance on bacteriophage PRD-1 transport in a sandy aquifer

    USGS Publications Warehouse

    Blanford, W.J.; Brusseau, M.L.; Yeh, T.-C.J.; Gerba, C.P.; Harvey, R.

    2005-01-01

    Experiments were conducted to evaluate the impact of groundwater chemistry and travel distance on the transport and fate behavior of PRD-1, a bacteriophage employed as a surrogate tracer for pathogenic enteric viruses. The experiments were conducted in the unconfined aquifer at the United States Geological Survey Cape Cod Toxic-Substances Hydrology Research Site in Falmouth, Massachusetts. The transport behavior of bromide (Br-) and PRD-1 were evaluated in a sewage-effluent contaminated zone and a shallower uncontaminated zone at this site. Several multilevel sampling devices located along a 13-m transect were used to collect vertically discrete samples to examine longitudinal and vertical variability of PRD-1 retardation and attenuation. The concentration of viable bacteriophage in the aqueous phase decreased greatly during the first few meters of transport. This decrease is attributed to a combination of colloid filtration (attachment) and inactivation. The removal was greater (10 -12 relative recovery) and occurred within the first meter for the uncontaminated zone, whereas it was lesser (10-9 relative recovery) and occurred over 4 m in the contaminated zone. The lesser removal observed for the contaminated zone is attributed to the influence of sorbed and dissolved organic matter, phosphate, and other anions, which are present in higher concentrations in the contaminated zone, on PRD-1 attachment. After the initial decrease, the aqueous PRD-1 concentrations remained essentially constant in both zones for the remainder of the tests (total travel distances of 13 m), irrespective of variations in geochemical properties within and between the two zones. The viable, mobile PRD-1 particles traveled at nearly the rate of bromide, which was used as a non-reactive tracer. The results of this study indicate that a small fraction of viable virus particles may persist in the aqueous phase and travel significant distances in the subsurface environment. ?? 2005 Elsevier Ltd

  20. Contributions of visual and proprioceptive information to travelled distance estimation during changing sensory congruencies.

    PubMed

    Campos, Jennifer L; Butler, John S; Bülthoff, Heinrich H

    2014-10-01

    Recent research has provided evidence that visual and body-based cues (vestibular, proprioceptive and efference copy) are integrated using a weighted linear sum during walking and passive transport. However, little is known about the specific weighting of visual information when combined with proprioceptive inputs alone, in the absence of vestibular information about forward self-motion. Therefore, in this study, participants walked in place on a stationary treadmill while dynamic visual information was updated in real time via a head-mounted display. The task required participants to travel a predefined distance and subsequently match this distance by adjusting an egocentric, in-depth target using a game controller. Travelled distance information was provided either through visual cues alone, proprioceptive cues alone or both cues combined. In the combined cue condition, the relationship between the two cues was manipulated by either changing the visual gain across trials (0.7×, 1.0×, 1.4×; Exp. 1) or the proprioceptive gain across trials (0.7×, 1.0×, 1.4×; Exp. 2). Results demonstrated an overall higher weighting of proprioception over vision. These weights were scaled, however, as a function of which sensory input provided more stable information across trials. Specifically, when visual gain was constantly manipulated, proprioceptive weights were higher than when proprioceptive gain was constantly manipulated. These results therefore reveal interesting characteristics of cue-weighting within the context of unfolding spatio-temporal cue dynamics.

  1. Branching angles reflect a trade-off between reducing trail maintenance costs or travel distances in leaf-cutting ants.

    PubMed

    Farji-Brener, Alejandro Gustavo; Chinchilla, Federico; Umaña, María Natalia; Ocasio-Torres, Maríia Elena; Chauta-Mellizo, Alexander; Acosta-Rojas, Diana; Marinaro, Sofía; Curth, Mónica de Torres; Amador-Vargas, Sabrina

    2015-02-01

    The design of transport paths in consuming entities that use routes to access food should be under strong selective pressures to reduce costs and increase benefits. We studied the adaptive nature of branching angles in foraging trail networks of the two most abundant tropical leaf-cutting ant species. We mathematically assessed how these angles should reflect the relative weight of the pressure for reducing either trail maintenance effort or traveling distances. Bifurcation angles of ant foraging trails strongly differed depending on the location of the nests. Ant colonies in open areas showed more acute branching angles, which best shorten travel distances but create longer new trail sections to maintain than a perpendicular branch, suggesting that trail maintenance costs are smaller compared to the benefit of reduced traveling distance. Conversely, ant colonies in forest showed less acute branching angles, indicating that maintenance costs are of larger importance relative to the benefits of shortening travel distances. The trail pattern evident in forests may be attributable to huge amounts of litterfall that .increase trail maintenance costs, and the abundant canopy cover that reduces traveling costs by mitigating direct sunlight and rain. These results suggest that branching angles represent a trade-off between reducing maintenance work and shortening travel distances, illustrating how animal constructions can adjust to diverse environmental conditions. This idea may help to understand diverse networks systems, including urban travel networks. PMID:26240872

  2. Dynamic Downslope Travel Distance Modeling: Interflow Modeling from Bottom of Slope Upwards

    NASA Astrophysics Data System (ADS)

    Bitew, M. M.; Jackson, C. R.; McDonnell, J.; Vache, K. B.; Griffiths, N.; Blake, J. I.

    2014-12-01

    Downslope travel distance concepts for interflow moving over a leaky restricting layer allow dynamic interflow modeling starting from the bottom of the slope and modeling only the active contributing area as opposed to the normal approach that models the entire slope from the ridgetop no flow boundary. In watersheds featuring deep groundwater and a low conductivity layer laying under permeable topsoil, interflow contributing areas expand and shrink based on the thickness of the perched layer, the topographic slope, and the ratio of hydraulic conductivity of topsoil to that of the impending layer. In this work, we present the development and application of two dynamic interflow models that implemented a mobile boundary condition to track flow from each of contributing cells starting from the edge of stream reaches extending upslope and constrained by downslope travel distance. Both analytical models are based on Boussinesq assumptions with percolation while one is continuous and the other is event-based. The continuous interflow model incorporates a two layer soil moisture accounting water balance analysis, pedotransfer function, percolation, and evaporation routines. The event rain based analytical solution generates interflow time series based on dynamically updated distribution function of downslope travel distances of contributing cells. We applied both modeling approaches in an intensively instrumented headwater basin in the Upper Coastal Plain of South Carolina. Both models showed good agreement with observed perched water depth, interflow discharge and soil moisture observations from 110m long open interflow interception trench whose 5.6 hectares of contributing hillslope were fitted with nested piezometers, soil moisture sensors, and series of V-notch weir boxes.

  3. Are teleoncology models merely about avoiding long distance travel for patients?

    PubMed

    Sabesan, S; Kelly, J

    2014-11-01

    Teleoncology models are used increasingly throughout the world as a means to provide access to quality cancer care for people in rural, remote and other disadvantaged settings. Some authors have suggested that teleoncology is merely about avoiding long distance travel. In this commentary we argue that the benefits of teleoncology extend beyond those of the patients and their families to the rural health system and beyond. We draw upon the literature and results of an evaluation of the Townsville Teleoncology Network (TTN) in North Queensland, Australia to support our arguments. PMID:25287049

  4. Effect of travel distance on household demand for typhoid vaccines: implications for planning.

    PubMed

    Kim, Dohyeong; Lauria, Donald T; Poulos, Christine; Dong, Baiqing; Whittington, Dale

    2014-01-01

    Typhoid fever causes millions of illnesses and hundreds of thousands of deaths yearly. Vaccinations would mitigate this problem, but the users would probably have to pay some or most of the cost. Several willingness-to-pay studies have assessed the effect of price on private demand to provide a basis for financial planning of campaigns, but the effect of travel distance, which is a potentially important determinant of demand, has not been studied. This paper thus has two objectives: (i) conduct a willingness-to-pay survey to assess the effects of distance, price and other variables on the private demand for typhoid vaccinations in a rural township of China where a campaign is under consideration; and (ii) embed the demand function in a mathematical model to address three planning questions; should each village have its own clinic, would one clinic be best or should the number of clinics be something in-between? Private vaccine demand was found to depend on and be inelastic with respect to both price and travel distance. A 1-km increase in distance caused the number of vaccinations demanded to decrease the same as a $0.5 increase in price. Thus, the marginal rate of substitution was $0.5 per km. A single clinic would be best for the township only if diseconomies of scale in supplying vaccinations exceeded the marginal rate of substitution. Otherwise, multiple clinics close to users would be optimal. Thus, deciding the number, location and capacities of clinics for vaccination planning is as important as deciding what price(s) to charge.

  5. Daily travel distances of zoo-housed chimpanzees and gorillas: implications for welfare assessments and space requirements.

    PubMed

    Ross, Stephen R; Shender, Marisa A

    2016-07-01

    The degree to which the relatively smaller area of artificial environments (compared with natural habitats) has measureable effects on the behavior and welfare of captive animals has been debated for many years. While there is little question that these spaces provide far less opportunity for natural ranging behavior and travel, less is known about the degree to which captive animals travel within their environments and what factors influence these travel patterns. We intensively studied the movement of zoo-housed chimpanzees and gorillas using a computer map interface and determined their mean daily travel and found they travelled similar distances each day when restricted to their indoor areas, but when provided additional outdoor space, chimpanzees tended to increase their travel to a greater extent than did gorillas. Both species travelled shorter distances than has been recorded for their wild counterparts, however, when given access to their full indoor-outdoor exhibit; those differences were not as substantive. These findings suggest that while large, complex naturalistic environments might not stimulate comparable species-typical travel patterns in captive apes, larger spaces that include outdoor areas may be better at replicating this behavioral pattern than smaller, indoor areas.

  6. Daily travel distances of zoo-housed chimpanzees and gorillas: implications for welfare assessments and space requirements.

    PubMed

    Ross, Stephen R; Shender, Marisa A

    2016-07-01

    The degree to which the relatively smaller area of artificial environments (compared with natural habitats) has measureable effects on the behavior and welfare of captive animals has been debated for many years. While there is little question that these spaces provide far less opportunity for natural ranging behavior and travel, less is known about the degree to which captive animals travel within their environments and what factors influence these travel patterns. We intensively studied the movement of zoo-housed chimpanzees and gorillas using a computer map interface and determined their mean daily travel and found they travelled similar distances each day when restricted to their indoor areas, but when provided additional outdoor space, chimpanzees tended to increase their travel to a greater extent than did gorillas. Both species travelled shorter distances than has been recorded for their wild counterparts, however, when given access to their full indoor-outdoor exhibit; those differences were not as substantive. These findings suggest that while large, complex naturalistic environments might not stimulate comparable species-typical travel patterns in captive apes, larger spaces that include outdoor areas may be better at replicating this behavioral pattern than smaller, indoor areas. PMID:26968410

  7. Traveling salesman problems with PageRank Distance on complex networks reveal community structure

    NASA Astrophysics Data System (ADS)

    Jiang, Zhongzhou; Liu, Jing; Wang, Shuai

    2016-12-01

    In this paper, we propose a new algorithm for community detection problems (CDPs) based on traveling salesman problems (TSPs), labeled as TSP-CDA. Since TSPs need to find a tour with minimum cost, cities close to each other are usually clustered in the tour. This inspired us to model CDPs as TSPs by taking each vertex as a city. Then, in the final tour, the vertices in the same community tend to cluster together, and the community structure can be obtained by cutting the tour into a couple of paths. There are two challenges. The first is to define a suitable distance between each pair of vertices which can reflect the probability that they belong to the same community. The second is to design a suitable strategy to cut the final tour into paths which can form communities. In TSP-CDA, we deal with these two challenges by defining a PageRank Distance and an automatic threshold-based cutting strategy. The PageRank Distance is designed with the intrinsic properties of CDPs in mind, and can be calculated efficiently. In the experiments, benchmark networks with 1000-10,000 nodes and varying structures are used to test the performance of TSP-CDA. A comparison is also made between TSP-CDA and two well-established community detection algorithms. The results show that TSP-CDA can find accurate community structure efficiently and outperforms the two existing algorithms.

  8. Controlled Study of Correlation of Biomechanical Profile of Hemiparetic Patients with Distance Travelled in Six Minutes

    PubMed Central

    Moura, Laís Moreira; Quintão, Mônica Maria Pena; de Carvalho, Karen Santos R.; Carrapatoso, Beatriz Cantanhede; Malfacini, Sabrina Lindenberg L.; da Silva, André Custódio; Orsini, Marco; Nascimento, Osvaldo J.M.; Chermont, Sergio S.M.C.

    2015-01-01

    The six-minute walking test (6MWT) is used to assess exercise tolerance that is associated with motor function of the lower limbs in hemiparetic patients. It is suggested that, for post-stroke subjects, performance in the 6MWT may be limited by biomechanical and cardiovascular factors. Our aim is to determine the correlation between the six-minute walk distance (6MWD) and the biomechanical profile of hemiparetic patients. During this cross-sectional controlled study, 10 hemiparetic patients with heart failure underwent 6MWT (ATS protocol). Tonus (Ashworth Scale) and goniometry of the lower limbs were measured. The average of 6MWD in two tests was 279±8 m. There was a negative correlation between the degree of spasticity for both the sural triceps (r=–0.57, P<0.05), quadriceps (r=–0.58, P<0.05) and the limitation in ankle dorsiflexion and the 6MWD (r=–0.76, P<0.05). Also, there was correlation between hip extension and ankle dorsiflexion limitations with 6MWD (r=0.66, P<0.05), (r=0.77, P<0.05). The negative correlation between the highest spasticity in paretic limb and the 6MWD and the correlation between the lower movement range of paretic hip and ankle suggest association with these factors and gait velocity in 6MWT. Loss percentage represents the percentage calculation between distance traveled and the distance predicted achieved by patients. In this study, the negative correlation between the percentage of loss of 6MWD and the limitation in the ankle dorsiflexion movement suggests that for a minor motion arch of the ankle, there is a higher percentage of walking distance loss foretold. PMID:26487924

  9. Association of increased travel distance to dialysis units with the risk of anemia in rural chronic hemodialysis elderly.

    PubMed

    Chao, Chia-Ter; Lai, Chun-Fu; Huang, Jenq-Wen; Chiang, Chih-Kang; Huang, Sheng-Jen

    2015-01-01

    Geographic remoteness has been found to influence health-related outcomes negatively. As reported in the literature, rural dialysis patients have a higher risk of mortality with increasing travel distance to dialysis units. However, few studies have focused on the impact of travel distances on the development of dialysis complications. We utilized a prospectively collected chronic hemodialysis patient cohort from a rural regional hospital for analysis. Data on demographics, comorbidities, and serum laboratory results were obtained. Correlation analyses between travel distance to dialysis units and dialysis complications were conducted, and significantly correlated parameters were entered into multivariate logistic regression models to determine their exact associations. A total of 46 rural chronic hemodialysis patients were enrolled, with an average age higher than others in the literature. Significant correlation was found between travel distance and serum hemoglobin levels (R(2) = -0.34, P value = 0.029). Multivariate logistic regression found that every 1 km increase in travel distance was associated with an increased risk of anemia (hemoglobin <9 g/dL) (odds ratio 1.46; P value = 0.01). Sensitivity analyses further showed that the associated risk was partially attenuated by serum albumin (odds ratio 1.83; P value = 0.07) and ferritin (odds ratio 1.39; P value = 0.08) levels. This is the first study to demonstrate the association between increased travel distance to dialysis units and the risk of anemia in chronic dialysis patients, especially elderly. Malnutrition, inflammation, and atherosclerosis syndrome could be partially responsible for the observed association. Further research is required to confirm our findings.

  10. Association between in-transit loss, internal trailer temperature, and distance traveled by Ontario market hogs.

    PubMed

    Haley, Charles; Dewey, Catherine E; Widowski, Tina; Friendship, Robert

    2008-10-01

    An observational study was conducted from July to October 2004 to determine the association between in-transit losses of swine and internal trailer temperature after controlling for loading density, trip distance, herd size, and random trip effect. A convenience sample of 3 trucking companies was used to collect temperature, relative humidity, and global positioning data for 104 trips that delivered 21,834 pigs from 371 producers to Ontario abattoirs. The association between in-transit loss and trailer temperature was determined using the 90th percentiles of internal temperature for each trip. Average loading density was 0.36 m2/100 kg pig (range 0.28 to 0.50 m2/100 kg pig). Average in-transit loss was 0.12%; however, 94% of producers experienced no losses. As the 90th percentile of internal trailer temperature increased from a range of 8.6 degrees C to 23.3 degrees C to a range of 23.4 degrees C to 26.1degreesC, average in-transit loss ratio increased approximately 3-fold, with an additional 2-fold increase as the range increased from 26.2 degrees C to 28.9 degrees C to 29.0 degrees C to 30.5 degrees C. As the 90th percentile of temperature increased by 1degreesC over the full range of temperatures in this study, in-transit loss was expected to increase 1.26 times. The in-transit loss was expected to decrease 0.81 times for each 50-km increase in distance traveled between the farm and the abattoir. PMID:19086369

  11. Surveillance of travel-associated gastrointestinal infections in Norway, 2009-2010: are they all actually imported?

    PubMed

    Guzman-Herrador, B; Vold, L; Nygard, K

    2012-10-11

    The Norwegian Surveillance System for Communicable Diseases (MSIS) includes variables related to travel for clinicians to fill when notifying travel-associated infections. We measured the completeness and validated the travel-history information for salmonellosis, campylobacteriosis, giardiasis and shigellosis reported in 2009-2010. Of all 8,978 selected infections in MSIS, 8,122 (91%) were reported with place of infection of which 5,236 (65%) were notified as acquired abroad, including 5,017 with symptoms. Of these, 2,972 (59%) notifications had information on both date of arrival in Norway and date of symptom onset, so time between travel and illness onset could be assessed. Taking in account the incubation period, of the 1,435 infections reported as travel-associated and for which symptom onset occurred after return to Norway, 1,404 (98%) would have indeed been acquired abroad. We found a high level of completeness for the variable 'place of infection'. Our evaluation suggests that the validity of this information is high. However, incomplete data in the variables 'return date to Norway' and 'date of symptoms onset', only allowed assessment of the biological plausibility of being infected abroad for 59% of the cases. We encourage clinicians to report more complete travel information. High quality information on travel-associated gastrointestinal infections is crucial for understanding trends in domestic and imported cases and evaluating implemented control measures.

  12. Method paper--distance and travel time to casualty clinics in Norway based on crowdsourced postcode coordinates: a comparison with other methods.

    PubMed

    Raknes, Guttorm; Hunskaar, Steinar

    2014-01-01

    We describe a method that uses crowdsourced postcode coordinates and Google maps to estimate average distance and travel time for inhabitants of a municipality to a casualty clinic in Norway. The new method was compared with methods based on population centroids, median distance and town hall location, and we used it to examine how distance affects the utilisation of out-of-hours primary care services. At short distances our method showed good correlation with mean travel time and distance. The utilisation of out-of-hours services correlated with postcode based distances similar to previous research. The results show that our method is a reliable and useful tool for estimating average travel distances and travel times.

  13. Improving the accuracy of estimates of animal path and travel distance using GPS drift-corrected dead reckoning.

    PubMed

    Dewhirst, Oliver P; Evans, Hannah K; Roskilly, Kyle; Harvey, Richard J; Hubel, Tatjana Y; Wilson, Alan M

    2016-09-01

    Route taken and distance travelled are important parameters for studies of animal locomotion. They are often measured using a collar equipped with GPS. Collar weight restrictions limit battery size, which leads to a compromise between collar operating life and GPS fix rate. In studies that rely on linear interpolation between intermittent GPS fixes, path tortuosity will often lead to inaccurate path and distance travelled estimates. Here, we investigate whether GPS-corrected dead reckoning can improve the accuracy of localization and distance travelled estimates while maximizing collar operating life. Custom-built tracking collars were deployed on nine freely exercising domestic dogs to collect high fix rate GPS data. Simulations were carried out to measure the extent to which combining accelerometer-based speed and magnetometer heading estimates (dead reckoning) with low fix rate GPS drift correction could improve the accuracy of path and distance travelled estimates. In our study, median 2-dimensional root-mean-squared (2D-RMS) position error was between 158 and 463 m (median path length 16.43 km) and distance travelled was underestimated by between 30% and 64% when a GPS position fix was taken every 5 min. Dead reckoning with GPS drift correction (1 GPS fix every 5 min) reduced 2D-RMS position error to between 15 and 38 m and distance travelled to between an underestimation of 2% and an overestimation of 5%. Achieving this accuracy from GPS alone would require approximately 12 fixes every minute and result in a battery life of approximately 11 days; dead reckoning reduces the number of fixes required, enabling a collar life of approximately 10 months. Our results are generally applicable to GPS-based tracking studies of quadrupedal animals and could be applied to studies of energetics, behavioral ecology, and locomotion. This low-cost approach overcomes the limitation of low fix rate GPS and enables the long-term deployment of lightweight GPS collars

  14. Improving the accuracy of estimates of animal path and travel distance using GPS drift-corrected dead reckoning.

    PubMed

    Dewhirst, Oliver P; Evans, Hannah K; Roskilly, Kyle; Harvey, Richard J; Hubel, Tatjana Y; Wilson, Alan M

    2016-09-01

    Route taken and distance travelled are important parameters for studies of animal locomotion. They are often measured using a collar equipped with GPS. Collar weight restrictions limit battery size, which leads to a compromise between collar operating life and GPS fix rate. In studies that rely on linear interpolation between intermittent GPS fixes, path tortuosity will often lead to inaccurate path and distance travelled estimates. Here, we investigate whether GPS-corrected dead reckoning can improve the accuracy of localization and distance travelled estimates while maximizing collar operating life. Custom-built tracking collars were deployed on nine freely exercising domestic dogs to collect high fix rate GPS data. Simulations were carried out to measure the extent to which combining accelerometer-based speed and magnetometer heading estimates (dead reckoning) with low fix rate GPS drift correction could improve the accuracy of path and distance travelled estimates. In our study, median 2-dimensional root-mean-squared (2D-RMS) position error was between 158 and 463 m (median path length 16.43 km) and distance travelled was underestimated by between 30% and 64% when a GPS position fix was taken every 5 min. Dead reckoning with GPS drift correction (1 GPS fix every 5 min) reduced 2D-RMS position error to between 15 and 38 m and distance travelled to between an underestimation of 2% and an overestimation of 5%. Achieving this accuracy from GPS alone would require approximately 12 fixes every minute and result in a battery life of approximately 11 days; dead reckoning reduces the number of fixes required, enabling a collar life of approximately 10 months. Our results are generally applicable to GPS-based tracking studies of quadrupedal animals and could be applied to studies of energetics, behavioral ecology, and locomotion. This low-cost approach overcomes the limitation of low fix rate GPS and enables the long-term deployment of lightweight GPS collars.

  15. Spatial working memory in immersive virtual reality foraging: path organization, traveling distance and search efficiency in humans (Homo sapiens).

    PubMed

    De Lillo, Carlo; Kirby, Melissa; James, Frances C

    2014-05-01

    Search and serial recall tasks were used in the present study to characterize the factors affecting the ability of humans to keep track of a set of spatial locations while traveling in an immersive virtual reality foraging environment. The first experiment required the exhaustive exploration of a set of locations following a procedure previously used with other primate and non-primate species to assess their sensitivity to the geometric arrangement of foraging sites. The second experiment assessed the dependency of search performance on search organization by requiring the participants to recall specific trajectories throughout the foraging space. In the third experiment, the distance between the foraging sites was manipulated in order to contrast the effects of organization and traveling distance on recall accuracy. The results show that humans benefit from the use of organized search patterns when attempting to monitor their travel though either a clustered "patchy" space or a matrix of locations. Their ability to recall a series of locations is dependent on whether the order in which they are explored conformed or did not conform to specific organization principles. Moreover, the relationship between search efficiency and search organization is not confounded by effects of traveling distance. These results indicate that in humans, organizational factors may play a large role in their ability to forage efficiently. The extent to which such dependency may pertain to other primates and could be accounted for by visual organization processes is discussed on the basis of previous studies focused on perceptual grouping, search, and serial recall in non-human species. PMID:24038208

  16. Spatial working memory in immersive virtual reality foraging: path organization, traveling distance and search efficiency in humans (Homo sapiens).

    PubMed

    De Lillo, Carlo; Kirby, Melissa; James, Frances C

    2014-05-01

    Search and serial recall tasks were used in the present study to characterize the factors affecting the ability of humans to keep track of a set of spatial locations while traveling in an immersive virtual reality foraging environment. The first experiment required the exhaustive exploration of a set of locations following a procedure previously used with other primate and non-primate species to assess their sensitivity to the geometric arrangement of foraging sites. The second experiment assessed the dependency of search performance on search organization by requiring the participants to recall specific trajectories throughout the foraging space. In the third experiment, the distance between the foraging sites was manipulated in order to contrast the effects of organization and traveling distance on recall accuracy. The results show that humans benefit from the use of organized search patterns when attempting to monitor their travel though either a clustered "patchy" space or a matrix of locations. Their ability to recall a series of locations is dependent on whether the order in which they are explored conformed or did not conform to specific organization principles. Moreover, the relationship between search efficiency and search organization is not confounded by effects of traveling distance. These results indicate that in humans, organizational factors may play a large role in their ability to forage efficiently. The extent to which such dependency may pertain to other primates and could be accounted for by visual organization processes is discussed on the basis of previous studies focused on perceptual grouping, search, and serial recall in non-human species.

  17. Assessment of topographic and drainage network controls on debris-flow travel distance along the west coast of the United States

    USGS Publications Warehouse

    Coe, Jeffrey A.; Reid, Mark E.; Brien, Dainne L.; Michael, John A.

    2011-01-01

    To better understand controls on debris-flow entrainment and travel distance, we examined topographic and drainage network characteristics of initiation locations in two separate debris-flow prone areas located 700 km apart along the west coast of the U.S. One area was located in northern California, the other in southern Oregon. In both areas, debris flows mobilized from slides during large storms, but, when stratified by number of contributing initiation locations, median debris-flow travel distances in Oregon were 5 to 8 times longer than median distances in California. Debris flows in Oregon readily entrained channel material; entrainment in California was minimal. To elucidate this difference, we registered initiation locations to high-resolution airborne LiDAR, and then examined travel distances with respect to values of slope, upslope contributing area, planform curvature, distance from initiation locations to the drainage network, and number of initiation areas that contributed to flows. Results show distinct differences in the topographic and drainage network characteristics of debris-flow initiation locations between the two study areas. Slope and planform curvature of initiation locations (landslide headscarps), commonly used to predict landslide-prone areas, were not useful for predicting debris-flow travel distances. However, a positive, power-law relation exists between median debris-flow travel distance and the number of contributing debris-flow initiation locations. Moreover, contributing area and the proximity of the initiation locations to the drainage network both influenced travel distances, but proximity to the drainage network was the better predictor of travel distance. In both study areas, flows that interacted with the drainage network flowed significantly farther than those that did not. In California, initiation sites within 60 m of the network were likely to reach the network and generate longtraveled flows; in Oregon, the threshold was

  18. [Health risks of long-distance air travel. Role of the general practitioner].

    PubMed

    Bazex, Jacques; Cabanis, Emmanuel Alain

    2010-06-01

    Air transport is seeing an increase in long-distance flights (12-16 hours average flight time), greater seating capacity, and a higher proportion of elderly, and hence more fragile, passengers. The French Academy of Medicine recommends that medical care be reinforced, particularly on long-distance flights, through the following measures: (i) passengers should be informed in advance of potential risks, through a Passenger's Guide, (ii) all future passengers should be encouraged to seek health advice and information from their general practitioner, (iii) flight crew members should receive training as "in-flight medical correspondents", and (iv) airlines and plane designers should reserve a "medical space" on the plane, equipped with appropriate medical materials.

  19. Grading vascularity from histopathological images based on traveling salesman distance and vessel size

    NASA Astrophysics Data System (ADS)

    Niazi, M. Khalid Khan; Hemminger, Jessica; Kurt, Habibe; Lozanski, Gerard; Gurcan, Metin

    2014-03-01

    Vascularity represents an important element of tissue/tumor microenvironment and is implicated in tumor growth, metastatic potential and resistence to therapy. Small blood vessels can be visualized using immunohistochemical stains specific to vascular cells. However, currently used manual methods to assess vascular density are poorly reproducible and are at best semi quantitative. Computer based quantitative and objective methods to measure microvessel density are urgently needed to better understand and clinically utilize microvascular density information. We propose a new method to quantify vascularity from images of bone marrow biopsies stained for CD34 vascular lining cells protein as a model. The method starts by automatically segmenting the blood vessels by methods of maxlink thresholding and minimum graph cuts. The segmentation is followed by morphological post-processing to reduce blast and small spurious objects from the bone marrow images. To classify the images into one of the four grades, we extracted 20 features from the segmented blood vessel images. These features include first four moments of the distribution of the area of blood vessels, first four moments of the distribution of 1) the edge weights in the minimum spanning tree of the blood vessels, 2) the shortest distance between blood vessels, 3) the homogeneity of the shortest distance (absolute difference in distance between consecutive blood vessels along the shortest path) between blood vessels and 5) blood vessel orientation. The method was tested on 26 bone marrow biopsy images stained with CD34 IHC stain, which were evaluated by three pathologists. The pathologists took part in this study by quantifying blood vessel density using gestalt assessment in hematopoietic bone marrow portions of bone marrow core biopsies images. To determine the intra-reader variability, each image was graded twice by each pathologist with two-week interval in between their readings. For each image, the ground

  20. The challenge of global water access monitoring: evaluating straight-line distance versus self-reported travel time among rural households in Mozambique.

    PubMed

    Ho, Jeff C; Russel, Kory C; Davis, Jennifer

    2014-03-01

    Support is growing for the incorporation of fetching time and/or distance considerations in the definition of access to improved water supply used for global monitoring. Current efforts typically rely on self-reported distance and/or travel time data that have been shown to be unreliable. To date, however, there has been no head-to-head comparison of such indicators with other possible distance/time metrics. This study provides such a comparison. We examine the association between both straight-line distance and self-reported one-way travel time with measured route distances to water sources for 1,103 households in Nampula province, Mozambique. We find straight-line, or Euclidean, distance to be a good proxy for route distance (R(2) = 0.98), while self-reported travel time is a poor proxy (R(2) = 0.12). We also apply a variety of time- and distance-based indicators proposed in the literature to our sample data, finding that the share of households classified as having versus lacking access would differ by more than 70 percentage points depending on the particular indicator employed. This work highlights the importance of the ongoing debate regarding valid, reliable, and feasible strategies for monitoring progress in the provision of improved water supply services.

  1. Travel distance and transformation of injected emulsified zerovalent iron nanoparticles in the subsurface during two and half years.

    PubMed

    Su, Chunming; Puls, Robert W; Krug, Thomas A; Watling, Mark T; O'Hara, Suzanne K; Quinn, Jacqueline W; Ruiz, Nancy E

    2013-08-01

    Nanoscale zerovalent iron (NZVI) such as Toda Kogyo RNIP-10DS has been used for site remediation, yet information is lacking regarding how far injected NZVI can travel, how long it lasts, and how it transforms to other minerals in a groundwater system. Previously we reported effective mass destruction of chlorinated ethenes dominated by tetrachloroethene (PCE) using emulsified zerovalent iron (EZVI) nanoparticles of RNIP-10DS in a shallow aquifer (1-6 m below ground surface, BGS) at Site 45, Marine Corps Recruit Depot, Parris Island, South Carolina, USA. Here we report test results on transport and transformation of injected EZVI in the subsurface. We employed two EZVI delivery methods: pneumatic injection and direct injection. Effective delivery of EZVI to the targeted zone was achieved with pneumatic injection showing a travel distance from injection points of up to 2.1 m and direct injection showing a travel distance up to 0.89 m. X-ray diffraction and scanning electron microscopy studies on particles harvested from well purge waters indicated that injected black colored NZVI (α-Fe(0)) was transformed largely to black colored cube-like and plate-like magnetites (Fe3O4, 0.1-1 μm, 0-9 months), then to orange colored irregularly shaped lepidocrocite (γ-FeOOH, 0.1-1 μm, 9 months to 2.5 years), then to yellowish lath-like goethite (α-FeOOH, 2-5 μm, 2.5 years) and ferrihydrite-like spherical particles (0.05-0.1 μm) in the top portion of the aquifer (1-2 m BGS). No α-Fe(0) was found in most monitoring wells three months after injection. The formed iron oxides appeared to have a wider range of particle size (submicron to 5 μm) than the pristine NZVI (35-140 nm). Injected NZVI was largely transformed to magnetite (0.1-1 μm) during two and half years in the lower portion of the aquifer (3-6 m).

  2. Mental traveling along psychological distances: The effects of cultural syndromes, perspective flexibility, and construal level.

    PubMed

    Wong, Vincent Chi; Wyer, Robert S

    2016-07-01

    Individuals' psychological distance from the stimuli they encounter in daily life can influence the abstractness or generality of the mental representations they form of these stimuli. However, these representations can also depend on the perspective from which the stimuli are construed. When individuals have either an individualistic social orientation or a short-term temporal orientation, they construe psychologically distal events more globally than they construe proximal ones, as implied by construal level theory (Trope & Liberman, 2010). When they have either a collectivistic social orientation or a long-term temporal orientation, however, they not only construe the implications of distal events more concretely than individuals with an egocentric perspective but also construe the implications of proximal events in more abstract terms. These effects are mediated by the flexibility of the perspectives that people take when they make judgments. Differences in perspective flexibility account for the impact of both situationally induced differences in social and temporal orientation and more chronic cultural differences in these orientations. (PsycINFO Database Record PMID:27337139

  3. 41 CFR 301-70.506 - How do we define actual cost and constructive cost when an employee interrupts a travel...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... appropriate en route travel time. ... cost and constructive cost when an employee interrupts a travel assignment because of an incapacitating illness or injury? 301-70.506 Section 301-70.506 Public Contracts and Property Management Federal...

  4. 41 CFR 301-70.506 - How do we define actual cost and constructive cost when an employee interrupts a travel...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... appropriate en route travel time. ... cost and constructive cost when an employee interrupts a travel assignment because of an incapacitating illness or injury? 301-70.506 Section 301-70.506 Public Contracts and Property Management Federal...

  5. 41 CFR 301-70.506 - How do we define actual cost and constructive cost when an employee interrupts a travel...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... appropriate en route travel time. ... cost and constructive cost when an employee interrupts a travel assignment because of an incapacitating illness or injury? 301-70.506 Section 301-70.506 Public Contracts and Property Management Federal...

  6. Lipopolysaccharide Density and Structure Govern the Extent and Distance of Nanoparticle Interaction with Actual and Model Bacterial Outer Membranes

    DOE PAGES

    Jacobson, Kurt H.; Gunsolus, Ian L.; Kuech, Thomas R.; Troiano, Julianne M.; Melby, Eric S.; Lohse, Samuel E.; Hu, Dehong; Chrisler, William B.; Murphy, Catherine J.; Orr, Galya; et al

    2015-07-24

    We report that design of nanomedicines and nanoparticle-based antimicrobial and antifouling formulations, and assessment of the potential implications of nanoparticle release into the environment require understanding nanoparticle interaction with bacterial surfaces. Here we demonstrate electrostatically driven association of functionalized nanoparticles with lipopolysaccharides of Gram-negative bacterial outer membranes and find that lipopolysaccharide structure influences the extent and location of binding relative to the lipid-solution interface. By manipulating the lipopolysaccharide content in Shewanella oneidensis outer membranes, we observed electrostatically driven interaction of cationic gold nanoparticles with the lipopolysaccharide-containing leaflet. We probed this interaction by quartz crystal microbalance with dissipation monitoring (QCM-D) andmore » second harmonic generation (SHG) using solid-supported lipopolysaccharide-containing bilayers. Association of cationic nanoparticles increased with lipopolysaccharide content, while no association of anionic nanoparticles was observed. The harmonic-dependence of QCM-D measurements suggested that a population of the cationic nanoparticles was held at a distance from the outer leaflet-solution interface of bilayers containing smooth lipopolysaccharides (those bearing a long O-polysaccharide). Additionally, smooth lipopolysaccharides held the bulk of the associated cationic particles outside of the interfacial zone probed by SHG. Lastly, our results demonstrate that positively charged nanoparticles are more likely to interact with Gram-negative bacteria than are negatively charged particles, and this interaction occurs primarily through lipopolysaccharides.« less

  7. Lipopolysaccharide Density and Structure Govern the Extent and Distance of Nanoparticle Interaction with Actual and Model Bacterial Outer Membranes

    SciTech Connect

    Jacobson, Kurt H.; Gunsolus, Ian L.; Kuech, Thomas R.; Troiano, Julianne M.; Melby, Eric S.; Lohse, Samuel E.; Hu, Dehong; Chrisler, William B.; Murphy, Catherine J.; Orr, Galya; Geiger, Franz M.; Haynes, Christy L.; Pedersen, Joel A.

    2015-07-24

    We report that design of nanomedicines and nanoparticle-based antimicrobial and antifouling formulations, and assessment of the potential implications of nanoparticle release into the environment require understanding nanoparticle interaction with bacterial surfaces. Here we demonstrate electrostatically driven association of functionalized nanoparticles with lipopolysaccharides of Gram-negative bacterial outer membranes and find that lipopolysaccharide structure influences the extent and location of binding relative to the lipid-solution interface. By manipulating the lipopolysaccharide content in Shewanella oneidensis outer membranes, we observed electrostatically driven interaction of cationic gold nanoparticles with the lipopolysaccharide-containing leaflet. We probed this interaction by quartz crystal microbalance with dissipation monitoring (QCM-D) and second harmonic generation (SHG) using solid-supported lipopolysaccharide-containing bilayers. Association of cationic nanoparticles increased with lipopolysaccharide content, while no association of anionic nanoparticles was observed. The harmonic-dependence of QCM-D measurements suggested that a population of the cationic nanoparticles was held at a distance from the outer leaflet-solution interface of bilayers containing smooth lipopolysaccharides (those bearing a long O-polysaccharide). Additionally, smooth lipopolysaccharides held the bulk of the associated cationic particles outside of the interfacial zone probed by SHG. Lastly, our results demonstrate that positively charged nanoparticles are more likely to interact with Gram-negative bacteria than are negatively charged particles, and this interaction occurs primarily through lipopolysaccharides.

  8. Lipopolysaccharide Density and Structure Govern the Extent and Distance of Nanoparticle Interaction with Actual and Model Bacterial Outer Membranes

    PubMed Central

    Jacobson, Kurt H.; Gunsolus, Ian L.; Kuech, Thomas R.; Troiano, Julianne M.; Melby, Eric S.; Lohse, Samuel E.; Hu, Dehong; Chrisler, William B.; Murphy, Catherine J.; Orr, Galya; Geiger, Franz M.; Haynes, Christy L.; Pedersen, Joel A.

    2015-01-01

    Design of nanomedicines and nanoparticle-based antimicrobial and antifouling formulations and assessment of the potential implications of nanoparticle release into the environment requires understanding nanoparticle interaction with bacterial surfaces. Here we demonstrate the electrostatically driven association of functionalized nanoparticles with lipopolysaccharides of Gram-negative bacterial outer membranes and find that lipopolysaccharide structure influences the extent and location of binding relative to the outer leaflet-solution interface. By manipulating the lipopolysaccharide content in Shewanella oneidensis outer membranes, we observed the electrostatically driven interaction of cationic gold nanoparticles with the lipopolysaccharide-containing leaflet. We probed this interaction by quartz crystal microbalance with dissipation monitoring (QCM-D) and second harmonic generation (SHG) using solid-supported lipopolysaccharide-containing bilayers. The association of cationic nanoparticles increased with lipopolysaccharide content, while no association of anionic nanoparticles was observed. The harmonic-dependence of QCM-D measurements suggested that a population of the cationic nanoparticles was held at a distance from the outer leaflet-solution interface of bilayers containing smooth lipopolysaccharides (those bearing a long O-polysaccharide). Additionally, smooth lipopolysaccharides held the bulk of the associated cationic particles outside of the interfacial zone probed by SHG. Our results demonstrate that positively charged nanoparticles are more likely to interact with Gram-negative bacteria than are negatively charged particles, and this interaction occurs primarily through lipopolysaccharides. PMID:26207769

  9. Lipopolysaccharide Density and Structure Govern the Extent and Distance of Nanoparticle Interaction with Actual and Model Bacterial Outer Membranes.

    PubMed

    Jacobson, Kurt H; Gunsolus, Ian L; Kuech, Thomas R; Troiano, Julianne M; Melby, Eric S; Lohse, Samuel E; Hu, Dehong; Chrisler, William B; Murphy, Catherine J; Orr, Galya; Geiger, Franz M; Haynes, Christy L; Pedersen, Joel A

    2015-09-01

    Design of nanomedicines and nanoparticle-based antimicrobial and antifouling formulations and assessment of the potential implications of nanoparticle release into the environment requires understanding nanoparticle interaction with bacterial surfaces. Here we demonstrate the electrostatically driven association of functionalized nanoparticles with lipopolysaccharides of Gram-negative bacterial outer membranes and find that lipopolysaccharide structure influences the extent and location of binding relative to the outer leaflet-solution interface. By manipulating the lipopolysaccharide content in Shewanella oneidensis outer membranes, we observed the electrostatically driven interaction of cationic gold nanoparticles with the lipopolysaccharide-containing leaflet. We probed this interaction by quartz crystal microbalance with dissipation monitoring (QCM-D) and second harmonic generation (SHG) using solid-supported lipopolysaccharide-containing bilayers. The association of cationic nanoparticles increased with lipopolysaccharide content, while no association of anionic nanoparticles was observed. The harmonic-dependence of QCM-D measurements suggested that a population of the cationic nanoparticles was held at a distance from the outer leaflet-solution interface of bilayers containing smooth lipopolysaccharides (those bearing a long O-polysaccharide). Additionally, smooth lipopolysaccharides held the bulk of the associated cationic particles outside of the interfacial zone probed by SHG. Our results demonstrate that positively charged nanoparticles are more likely to interact with Gram-negative bacteria than are negatively charged particles, and this interaction occurs primarily through lipopolysaccharides.

  10. Laboratory investigation of the distribution of travel distance and rest period of sediment particles from PTV data

    NASA Astrophysics Data System (ADS)

    Ferreira, Rui M. L.; Antico, Federica

    2016-04-01

    We analyze paths of sediment particles on cohesionless granular bet subjected to a turbulent open-channel flow. The key objective is to provide further insights on particle dispersion including resting times. Hence, we focus on the spatial and temporal scale identified by Nikora et al. (2002) as the global range, defined as the particle path composed of many intermediate range paths, i.e with several "starts" and "stops". This requires the calculation of the probability distribution functions of particle travel distances and of rest periods. The experimental work was performed at the Hydraulics Laboratory of IST-UL in a 12.5 m long, 0.405 m wide glass-walled flume recirculating water and sediment through independent circuits. The granular bed was a 4.0 m long and 2.5 cm deep reach filled with 5 mm diameter glass beads packed (with some vibration) to a void fraction of 0.356, typical of random packing. Upstream the mobile bed reach the bed was composed of glued particles to ensure the development of a boundary layer with the same roughness. Laboratory tests were run under conditions of weak beadload transport with Shields parameter (θ) in the range 0.007 to 0.030, Froude numbers (Fr) between 0.630 and 0.950 and boundary Reynolds number (Re_ast) in the range 130 to 300. White-coated particles with 5.0 mm diameter were introduced in the flow 3 m upstream the mobile bed reach. Particle motion was registered from above using a high-speed camera AVT Bonito CL-400 with resolution set to 2320 × 1000 px2 and frame rate of 170 fps. The field of view recorded was 77.0 cm long and 38.0 cm wide, covering almost all the width of the flume. The maximum duration of the runs was 20 min, during which more than 500 particle paths, including resting times, were registered. The video footage was subjected to a PTV (Particle Tracking Velocimetry) developed for the problem at hand. The algorithm includes the application of Gaussian filters and thresholding operations to identify the

  11. Laboratory investigation of the distribution of travel distance and rest period of sediment particles from PTV data

    NASA Astrophysics Data System (ADS)

    Ferreira, Rui M. L.; Antico, Federica

    2016-04-01

    We analyze paths of sediment particles on cohesionless granular bet subjected to a turbulent open-channel flow. The key objective is to provide further insights on particle dispersion including resting times. Hence, we focus on the spatial and temporal scale identified by Nikora et al. (2002) as the global range, defined as the particle path composed of many intermediate range paths, i.e with several "starts" and "stops". This requires the calculation of the probability distribution functions of particle travel distances and of rest periods. The experimental work was performed at the Hydraulics Laboratory of IST-UL in a 12.5 m long, 0.405 m wide glass-walled flume recirculating water and sediment through independent circuits. The granular bed was a 4.0 m long and 2.5 cm deep reach filled with 5 mm diameter glass beads packed (with some vibration) to a void fraction of 0.356, typical of random packing. Upstream the mobile bed reach the bed was composed of glued particles to ensure the development of a boundary layer with the same roughness. Laboratory tests were run under conditions of weak beadload transport with Shields parameter (θ) in the range 0.007 to 0.030, Froude numbers (Fr) between 0.630 and 0.950 and boundary Reynolds number (Re_ast) in the range 130 to 300. White-coated particles with 5.0 mm diameter were introduced in the flow 3 m upstream the mobile bed reach. Particle motion was registered from above using a high-speed camera AVT Bonito CL-400 with resolution set to 2320 × 1000 px2 and frame rate of 170 fps. The field of view recorded was 77.0 cm long and 38.0 cm wide, covering almost all the width of the flume. The maximum duration of the runs was 20 min, during which more than 500 particle paths, including resting times, were registered. The video footage was subjected to a PTV (Particle Tracking Velocimetry) developed for the problem at hand. The algorithm includes the application of Gaussian filters and thresholding operations to identify the

  12. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    NASA Technical Reports Server (NTRS)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2009-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time-distance helioseismology pipeline has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time-distance helioseismology: a Gabor wavelet fitting (Kosovichev and Duvall, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, 2002), and a linearized version of the minimization method (Gizon and Birch, 2004). Using Doppler velocity data from the Michelson Doppler Imager (MDI) instrument on board SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet Sun region, the method of Gizon and Birch (2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (1997) and Gizon and Birch (2002). We investigated the relationships among these three travel-time definitions, their sensitivities to fitting parameters, and estimated the random errors they produce

  13. Measurement and Interpretation of Travel-Time Shifts in the context of Time-Distance Helioseismic Detection of Meridional Flows in the Solar Convection Zone

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Duvall, T. L., Jr.; Hanasoge, S.; Hartlep, T.; Larson, T. P.; Kholikov, S.

    2014-12-01

    The role of meridional flow in maintaining the solar dynamo and differential rotation in the solar convection zone is not well understood and is currently under scrutiny. The traditional flux-transport dynamo models have posited the well known single-cell meridional flow with poleward flow at the photosphere and equatorward flow near the base of the convection zone. However, recent investigations seem to be revealing a different picture of meridional flow which is double celled in the radial direction with poleward flow at the photosphere and equatorward flow at a much shallower level in the convection zone. In this work time-distance helioseismology is used to probe the solar convection zone to accurately determine the structure of meridional circulation. Helioseismology uses the photospherically visible aspect of (acoustic, surface-gravity) waves, that propagate and interfere throughout the Sun to form standing oscillation modes, as probes to make inferences about the structure and flows on the solar surface and interior. Time-distance helioseismology is based on measuring the travel-times of wave-packets moving between distinct points on the solar surface. Travel-time shifts obtained by calculating the difference in the travel-times of counter-propagating waves between the same points on the solar surface yield information about flows throughout the solar convection zone. In this work time-distance techniques are applied on artificial and solar Doppler velocity images to detect travel-time shifts due to meridional flow. Modifications are suggested to enhance the signal-to-noise ratio of travel-time shift measurements. The artificial data is constructed by embedding various meridional flow models in 3D acoustic simulators, which is then used to discuss the interpretation of travel-time shifts, so that in the future an inversion procedure may be designed to calculate meridional flow velocities with greater accuracy. The solar data is obtained from the Helioseismic

  14. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Solar Dynamics Observatory-Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    NASA Technical Reports Server (NTRS)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, Thomas L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2010-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler-velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time - distance helioseismology pipeline (Zhao et al., Solar Phys. submitted, 2010) has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross-covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time - distance helioseismology: a Gabor-wavelet fitting (Kosovichev and Duvall, SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, Astrophys. J. 571, 966, 2002), and a linearized version of the minimization method (Gizon and Birch, Astrophys. J. 614, 472, 2004). Using Doppler-velocity data from the Michelson Doppler Imager (MDI) instrument onboard SOHO, we tested and compared these definitions for the mean and difference traveltime perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet-Sun region, the method of Gizon and Birch (Astrophys. J. 614, 472, 2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997) and Gizon and Birch (Astrophys. J. 571, 966, 2002). We investigated the relationships among

  15. Travel Distance and Transformation of Injected Emulsified Zerovalent Iron Nanoparticles in the Subsurface During Two and Half Years

    EPA Science Inventory

    Nanoscale zerovalent iron (NZVI) such as Toda Kogyo RNIP-10DS has been used for site remediation, yet information is lacking regarding how far injected NZVI can travel, how long it lasts, and how it transforms to other minerals in a groundwater system. Previously we reported effe...

  16. Consequences of long-distance swimming and travel over deep-water pack ice for a female polar bear during a year of extreme sea ice retreat

    USGS Publications Warehouse

    Durner, G.M.; Whiteman, J.P.; Harlow, H.J.; Amstrup, Steven C.; Regehr, E.V.; Ben-David, M.

    2011-01-01

    Polar bears (Ursus maritimus) prefer to live on Arctic sea ice but may swim between ice floes or between sea ice and land. Although anecdotal observations suggest that polar bears are capable of swimming long distances, no data have been available to describe in detail long distance swimming events or the physiological and reproductive consequences of such behavior. Between an initial capture in late August and a recapture in late October 2008, a radio-collared adult female polar bear in the Beaufort Sea made a continuous swim of 687 km over 9 days and then intermittently swam and walked on the sea ice surface an additional 1,800 km. Measures of movement rate, hourly activity, and subcutaneous and external temperature revealed distinct profiles of swimming and walking. Between captures, this polar bear lost 22% of her body mass and her yearling cub. The extraordinary long distance swimming ability of polar bears, which we confirm here, may help them cope with reduced Arctic sea ice. Our observation, however, indicates that long distance swimming in Arctic waters, and travel over deep water pack ice, may result in high energetic costs and compromise reproductive fitness. ?? 2011 US Government.

  17. A description of patient characteristics, insurance status and travel distance at a free inner-city clinic.

    PubMed

    Carranti, Barbara; Myers, Gina; Bowers, Leanne; Satterly, Lynn-Beth

    2012-01-01

    This study was designed to investigate patient characteristics at Amaus Health Services at Cathedral, a free medical clinic in Syracuse, New York which provides interim primary health care to the underserved and uninsured populations in the downtown area of Syracuse. The mission of the clinic is to serve an inner-city population. This study found that the clinic sees equal numbers of men and women and half of the visits were for chronic disease management. Patients traveled from 33 different zip codes, most of which were outside of the intended service area. In addition, of the 278 visits, 50 clinic users reported having some form of insurance. These findings can help Amaus leadership direct volunteers and donations to enhance the services provided, and may assist other areas of the country to identify needs for enhanced access as changes occur in the health care system.

  18. Influence of day length, ambient temperature, and seasonality on daily travel distance in the Yunnan snub-nosed monkey at Jinsichang, Yunnan, China.

    PubMed

    Baoping, Ren; Ming, Li; Yongcheng, Long; Fuwen, Wei

    2009-03-01

    This article examines the effect of ambient temperature, day length, weather conditions, and seasonality on daily path length (DPL) of a free-ranging group of Yunnan snub-nosed monkeys (Rhinopithecus bieti) using an auto-released GPS collar. Data were collected from December 17, 2003 to October 22, 2004 at Laojunshan in northwestern Yunnan province, China. The average DPL of the monkey group was 909+/-472 m (n=291), with the shortest distance being 180 m and the longest distance 3,626 m. Ambient temperature and day length were found to affect DPL. Both factors were positively correlated with DPL, which means that the monkey group traveled greater distances on longer and warmer days. At the study site, three distinct seasons were identified, and DPL did not vary significantly across these periods. The time of sunrise was not correlated with DPL. Nevertheless, we sometimes observed the group starting its daily trip later on cloudy days than on sunny days. Furthermore, weather conditions (e.g. rainy, cloudy, and sunny) did not influence the average DPL of the study group. Overall we found that the primary factors affecting DPL in R. bieti were day length and ambient temperature, especially daily highest temperature.

  19. TRAVEL FORECASTER

    NASA Technical Reports Server (NTRS)

    Mauldin, L. E.

    1994-01-01

    Business travel planning within an organization is often a time-consuming task. Travel Forecaster is a menu-driven, easy-to-use program which plans, forecasts cost, and tracks actual vs. planned cost for business-related travel of a division or branch of an organization and compiles this information into a database to aid the travel planner. The program's ability to handle multiple trip entries makes it a valuable time-saving device. Travel Forecaster takes full advantage of relational data base properties so that information that remains constant, such as per diem rates and airline fares (which are unique for each city), needs entering only once. A typical entry would include selection with the mouse of the traveler's name and destination city from pop-up lists, and typed entries for number of travel days and purpose of the trip. Multiple persons can be selected from the pop-up lists and multiple trips are accommodated by entering the number of days by each appropriate month on the entry form. An estimated travel cost is not required of the user as it is calculated by a Fourth Dimension formula. With this information, the program can produce output of trips by month with subtotal and total cost for either organization or sub-entity of an organization; or produce outputs of trips by month with subtotal and total cost for international-only travel. It will also provide monthly and cumulative formats of planned vs. actual outputs in data or graph form. Travel Forecaster users can do custom queries to search and sort information in the database, and it can create custom reports with the user-friendly report generator. Travel Forecaster 1.1 is a database program for use with Fourth Dimension Runtime 2.1.1. It requires a Macintosh Plus running System 6.0.3 or later, 2Mb of RAM and a hard disk. The standard distribution medium for this package is one 3.5 inch 800K Macintosh format diskette. Travel Forecaster was developed in 1991. Macintosh is a registered trademark of

  20. Impact of travel mode shift and trip distance on active and non-active transportation in the São Paulo Metropolitan Area in Brazil

    PubMed Central

    de Sá, Thiago Hérick; Parra, Diana C.; Monteiro, Carlos Augusto

    2015-01-01

    Background Changes in urban mobility play a major role in transforming metropolitan areas into healthier places. This study quantified the impact of changes in travel mode shift and trip distance on active and non-active transportation of working age adult population of São Paulo. Methods and findings Through different scenarios, we estimated the daily time spent in transportation per inhabitant (divided in active and non-active transportation time) and the proportion of inhabitants accumulating 30 min or more of daily active transportation. The replacement of individual for collective motorized modes in long distance trips (> 1000 m) in combination with the substitution of long for short trips positively impacted all outcomes. Compared to the current situation, there was an increase in the active transportation time (from 19.4 to 26.7 min/inhabitant), which also increased the proportion of adults active for transportation (from 27.6% to 35.4%). Additionally, the non-active transportation time decreased (from 67.0 to 26.2 min/inhabitant), which helped to reduce the total time spent in transportation (from 86.4 to 52.9 min/inhabitant). Conclusion Transport and urban planning policies to reduce individual motorized trips and the number of long trips might produce important health benefits, both by increasing population levels of active transportation and reducing the non-active and the total time of daily trips. PMID:26844071

  1. Program Tracks Cost Of Travel

    NASA Technical Reports Server (NTRS)

    Mauldin, Lemuel E., III

    1993-01-01

    Travel Forecaster is menu-driven, easy-to-use computer program that plans, forecasts cost, and tracks actual vs. planned cost of business-related travel of division or branch of organization and compiles information into data base to aid travel planner. Ability of program to handle multiple trip entries makes it valuable time-saving device.

  2. Traveling with breathing problems

    MedlinePlus

    Oxygen - travel; Collaped lung - travel; Chest surgery - travel; COPD - travel; Chronic obstructive airways disease - travel; Chronic obstructive lung disease - travel; Chronic bronchitis - travel; ...

  3. Connected Traveler

    SciTech Connect

    Schroeder, Alex

    2015-11-01

    The Connected Traveler project is a multi-disciplinary undertaking that seeks to validate potential for transformative transportation system energy savings by incentivizing efficient traveler behavior. This poster outlines various aspects of the Connected Traveler project, including market opportunity, understanding traveler behavior and decision-making, automation and connectivity, and a projected timeline for Connected Traveler's key milestones.

  4. Associations between the distance traveled from sale barns to commercial feedlots in the United States and overall performance, risk of respiratory disease, and cumulative mortality in feeder cattle during 1997 to 2009.

    PubMed

    Cernicchiaro, N; White, B J; Renter, D G; Babcock, A H; Kelly, L; Slattery, R

    2012-06-01

    Most beef cattle are transported at least once during their lives, and this potentially stressful practice may affect subsequent health and performance. Limited research is available quantifying the effects of transport on feedlot performance and health, and particularly the risk of bovine respiratory disease complex (BRD), which is the most common disease of weaned calves after arrival to the feedlot. The objective of this retrospective study was to determine potential associations between distance traveled (DTV) during transportation with health (cumulative BRD morbidity and mortality of all causes) and performance (ADG and HCW) parameters in cattle cohorts (n = 14,601) that arrived to 21 U.S. commercial feedlots from 1997 to 2009. Multivariable mixed-effects negative binomial and linear regression models were employed to determine associations between health and performance outcomes with DTV and other cohort-level demographic variables. Cattle were transported a median of 552 km from origin to feedlot with a mean (± SEM) of 698 ± 4.4 km. The mean (±SEM) cumulative BRD morbidity was 4.9% ± 0.01% (median = 1.1%; range: 0 to 100%) whereas the mean (±SEM) cumulative mortality due to all causes was 1.3% ± 0.01% (median = 0.8%; range: 0 to 28.7%). Distance traveled was significantly associated (P < 0.05) with BRD morbidity, overall mortality, HCW and ADG, and its effects were modified by demographic characteristics (i.e., cohort region of origin, mean arrival BW, gender, and the season of the year) of the cohort. Knowledge of the distance traveled during transportation could allow a more precise prediction of cattle feedlot health and performance.

  5. Further We Travel the Faster We Go

    PubMed Central

    Varga, Levente; Kovács, András; Tóth, Géza; Papp, István; Néda, Zoltán

    2016-01-01

    The average travelling speed increases in a nontrivial manner with the travel distance. This leads to scaling-like relations on quite extended spatial scales, for all mobility modes taken together and also for a given mobility mode in part. We offer a wide range of experimental results, investigating and quantifying this universal effect and its measurable causes. The increasing travelling speed with the travel distance arises from the combined effects of: choosing the most appropriate travelling mode; the structure of the travel networks; the travel times lost in the main hubs, starting or target cities; and the speed limit of roads and vehicles. PMID:26863605

  6. Further We Travel the Faster We Go.

    PubMed

    Varga, Levente; Kovács, András; Tóth, Géza; Papp, István; Néda, Zoltán

    2016-01-01

    The average travelling speed increases in a nontrivial manner with the travel distance. This leads to scaling-like relations on quite extended spatial scales, for all mobility modes taken together and also for a given mobility mode in part. We offer a wide range of experimental results, investigating and quantifying this universal effect and its measurable causes. The increasing travelling speed with the travel distance arises from the combined effects of: choosing the most appropriate travelling mode; the structure of the travel networks; the travel times lost in the main hubs, starting or target cities; and the speed limit of roads and vehicles.

  7. Further We Travel the Faster We Go.

    PubMed

    Varga, Levente; Kovács, András; Tóth, Géza; Papp, István; Néda, Zoltán

    2016-01-01

    The average travelling speed increases in a nontrivial manner with the travel distance. This leads to scaling-like relations on quite extended spatial scales, for all mobility modes taken together and also for a given mobility mode in part. We offer a wide range of experimental results, investigating and quantifying this universal effect and its measurable causes. The increasing travelling speed with the travel distance arises from the combined effects of: choosing the most appropriate travelling mode; the structure of the travel networks; the travel times lost in the main hubs, starting or target cities; and the speed limit of roads and vehicles. PMID:26863605

  8. Are GIS-modelled routes a useful proxy for the actual routes followed by commuters?

    PubMed Central

    Dalton, Alice M; Jones, Andrew P; Panter, Jenna; Ogilvie, David

    2015-01-01

    Active commuting offers the potential to increase physical activity among adults by being built into daily routines. Characteristics of the route to work may influence propensity to walk or cycle. Geographic information system (GIS) software is often used to explore this by modelling routes between home and work. However, if the validity of modelled routes depends on the mode of travel used, studies of environmental determinants of travel may be biased. We aimed to understand how well modelled routes reflect those actually taken, and what characteristics explain these differences. We compared modelled GIS shortest path routes with actual routes measured using QStarz BT-Q1000X Global Positioning System (GPS) devices in a free-living sample of adults working in Cambridge and using varying travel modes. Predictors of differences, according to length and percentage overlap, between the two route sets were assessed using multilevel regression models and concordance coefficients. The 276 trips, made by 51 participants, were on average 27% further than modelled routes, with an average geographical overlap of 39%. However, predictability of the route depended on travel mode. For route length, there was moderate-to-substantial agreement for journeys made on foot and by bicycle. Route overlap was lowest for trips made by car plus walk (22%). The magnitude of difference depended on other journey characteristics, including travelling via intermediate destinations, distance, and use of busy roads. In conclusion, GIS routes may be acceptable for distance estimation and to explore potential routes, particularly active commuting. However, GPS should be used to obtain accurate estimates of environmental contexts in which commuting behaviour actually occurs. Public health researchers should bear these considerations in mind when studying the geographical determinants and health implications of commuting behaviour, and when recommending policy changes to encourage active travel. PMID

  9. Distance estimation in the third dimension in desert ants.

    PubMed

    Wohlgemuth, S; Ronacher, B; Wehner, R

    2002-05-01

    Desert ants of the genus Cataglyphis perform large-scale foraging excursions from which they return to their nest by path integration. They do so by integrating courses steered and the distances travelled into a continually updated home vector. While it is known that the angular orientation is based on skylight cues, it still is largely enigmatic how the ants measure distances travelled. We extended the ants' task into the third dimension by training them to walk within an array of uphill and downhill channels, and later testing them on flat terrain, or vice versa. In these tests the ants indicated homing distances that did not correspond to the distances actually travelled, but to the ground distances; that is, to the sum of the horizontal projections of the uphill and downhill segments of the ants' paths. These results suggest a much more sophisticated mechanism of distance estimation than hitherto thought. The ants must be able to measure the slopes of undulating terrain and to integrate this information into their "odometer" for the distance estimation process.

  10. Travel medicine

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Abstract Objective To define the practice of travel medicine, provide the basics of a comprehensive pretravel consultation for international travelers, and assist in identifying patients who might require referral to travel medicine professionals. Sources of information Guidelines and recommendations on travel medicine and travel-related illnesses by national and international travel health authorities were reviewed. MEDLINE and EMBASE searches for related literature were also performed. Main message Travel medicine is a highly dynamic specialty that focuses on pretravel preventive care. A comprehensive risk assessment for each individual traveler is essential in order to accurately evaluate traveler-, itinerary-, and destination-specific risks, and to advise on the most appropriate risk management interventions to promote health and prevent adverse health outcomes during travel. Vaccinations might also be required and should be personalized according to the individual traveler’s immunization history, travel itinerary, and the amount of time available before departure. Conclusion A traveler’s health and safety depends on a practitioner’s level of expertise in providing pretravel counseling and vaccinations, if required. Those who advise travelers are encouraged to be aware of the extent of this responsibility and to refer all high-risk travelers to travel medicine professionals whenever possible. PMID:25500599

  11. Blood Clots and Travel: What You Need to Know

    MedlinePlus

    ... More than 300 million people travel on long-distance flights (generally more than four hours) each year. ... can be a serious risk for some long-distance travelers. Most information about blood clots and long- ...

  12. Travelers' Diarrhea

    MedlinePlus

    ... or Zika Travel to the Olympics Infographic: Olympic Games in Brazil Olympics Freqently Asked Questions Find a ... Travelers Zika infographic: Enjoy Your Vacation Infographic: Olympic Games in Brazil Pack smart to prevent Zika Prevent ...

  13. Travelers' Health

    MedlinePlus

    ... Citizens and Residents Living in Areas with Ongoing Zika Virus Transmission Guidelines for Travelers Visiting Friends and Family ... Vaccines. Medicines. Advice. Do you have questions about Zika virus or travel to the Olympics ? Destinations Who are ...

  14. Armchair Travels.

    ERIC Educational Resources Information Center

    Brodie, Carolyn S.

    1994-01-01

    Includes ideas and activities for school library media specialists relating to vacationing and traveling, including the use of maps, travel brochures, travel diaries, postcards, videos, slides, and guest speakers. An annotated bibliography of 75 pertinent sources of information, including picture books, intermediate level, nonfiction,…

  15. Travelers' Health: Travel and Breastfeeding

    MedlinePlus

    ... providers should explain clearly to breastfeeding mothers the value of continuing breastfeeding during travel. For the first 6 months of life, exclusive breastfeeding is recommended. This is especially important during travel because exclusive breastfeeding means feeding only ...

  16. Understanding taxi travel patterns

    NASA Astrophysics Data System (ADS)

    Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

    2016-09-01

    Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

  17. [Travel thrombosis, 2008].

    PubMed

    Sándor, Tamás

    2009-01-18

    In Hungary, the first studies on travel thrombosis were published at the beginning of the 2000s. In this paper recent investigational results of this special type of venous thrombosis have been reviewed. Travel thrombosis is a subgroup of sitting thromboses. It is a consequence of prolonged sitting which is common of ground transportation and air travel. More and more computer-linked sitting thromboses have been observed as well. Long-haul air travel related venous thrombosis is a multifactorial disease. Possible contributory risk factors are in connection with the milieu of the cabin. Various investigations evaluated the effect of immobilization and hypobaric hypoxia on thrombin generation and fibrinolysis. The studies differed much in participants' characteristics, duration and type of exposure and statistical analysis, so the results are contradictory. Personal, traveller-related risk factors may be regarded as triggers. The presently available evidences do not permit to assess the exact actual risk. For healthy young passengers there seem to be low risk. However, passengers suffering from predisposing factors for venous thromboembolism can be exposed to serious hazards, if they fly more than 5000 km or travel more than 8 hours. Proper safety measures are summarized on the basis of recent international recommendations.

  18. Travelers' thrombosis.

    PubMed

    Johnston, Raymond V; Hudson, Martin F

    2014-02-01

    The suggestion that venous thromboembolism (VTE) is associated with air travel has for several decades been the subject of both "media hype" and extensive debate in the medical literature. As emotion and anecdote is often a feature in this debate, it is therefore necessary to separate evidence from anecdote. "Travelers' thrombosis" is a more appropriate term because the evidence suggests that any form of travel involving immobility lasting more than 4 h can predispose to thrombosis. There is no unique factor in the air travel cabin environment that has been shown to have any effect on the coagulation cascade. Prevention of thrombosis in any form of travel, including air travel, requires being aware of the issue and making an adequate risk assessment together with appropriate prophylactic measures.

  19. Travelers' thrombosis.

    PubMed

    Johnston, Raymond V; Hudson, Martin F

    2014-02-01

    The suggestion that venous thromboembolism (VTE) is associated with air travel has for several decades been the subject of both "media hype" and extensive debate in the medical literature. As emotion and anecdote is often a feature in this debate, it is therefore necessary to separate evidence from anecdote. "Travelers' thrombosis" is a more appropriate term because the evidence suggests that any form of travel involving immobility lasting more than 4 h can predispose to thrombosis. There is no unique factor in the air travel cabin environment that has been shown to have any effect on the coagulation cascade. Prevention of thrombosis in any form of travel, including air travel, requires being aware of the issue and making an adequate risk assessment together with appropriate prophylactic measures. PMID:24597166

  20. Traveler's Diarrhea.

    PubMed

    Giddings, Stanley L; Stevens, A Michal; Leung, Daniel T

    2016-03-01

    Traveler's diarrhea (TD) is the most common travel-related illness, and it can have a significant impact on the traveler. Pretravel consultation provides an excellent opportunity for the clinician to counsel the traveler and discuss strategies such as food and water hygiene, vaccinations, and medications for prophylaxis or self-treatment that may decrease the incidence and impact of TD. Postinfectious sequelae, such as postinfectious irritable bowel syndrome, reactive arthritis, and Guillain-Barre syndrome, may develop weeks or months after return. PMID:26900116

  1. Travelling diabetics.

    PubMed

    Chełmińska, Katarzyna; Jaremin, Bogdan

    2002-01-01

    During the past several decades, the number of both business and tourist travels has greatly increased. Among them are persons suffering from chronic diseases, including diabetics for whom travels pose the additional health-hazard. Irrespective of better education, self-control and constantly improving quality of specialistic equipment available, diabetics still are the group of patients requiring particular attention. In the case of travelling diabetics, problems may occur concerning the transport and storage of insulin, as well as control of glycaemia, all caused by irregularity of meals, variable diet, physical activity, stress, kinetosis (sea voyages), and the change of time zones. The travel may as well evoke ailments caused by the change of climate and concomitant diseases such as traveller's diarrhoea, malaria, etc. Apart from avoiding glycaemia fluctuations, important for retaining health of diabetics is the prevention of other diseases and carrying the necessary drugs.

  2. Self-motion perception compresses time experienced in return travel.

    PubMed

    Seno, Takeharu; Ito, Hiroyuki; Shoji, Sunaga

    2011-01-01

    It is often anecdotally reported that time experienced in return travel (back to the start point) seems shorter than time spent in outward travel (travel to a new destination). Here, we report the first experimental results showing that return travel time is experienced as shorter than the actual time. This discrepancy is induced by the existence of self-motion perception.

  3. [Adventure travel].

    PubMed

    Beck, Bernhard R

    2013-06-01

    Extreme travelling experiences appear to be a quite popular kick offered by tourist operators and sought by some travellers. But some travellers expose themselves to increased risk also during normal holidays, either voluntarily by booking hikes or tours leading them to adventurous locations or to unexpectedly encountering dangerous situations. In planned adventures, precise information in advance, good physical condition, careful planning, and profound medical preparation may contribute to a less hazardous adventure. Advising medical persons may need an expert consultation for specific topics in order to optimise the preparation. Based on three specific environmental situations (jungle, desert, and cave) the specific conditions, dangers and some medical aspects are outlined. PMID:23732454

  4. Time-of-travel data for Nebraska streams, 1968 to 1977

    USGS Publications Warehouse

    Petri, L.R.

    1984-01-01

    This report documents the results of 10 time-of-travel studies, using ' dye-tracer ' methods, conducted on five streams in Nebraska during the period 1968 to 1977. Streams involved in the studies were the North Platte, North Loup, Elkhorn, and Big Blue Rivers and Salt Creek. Rhodamine WT dye in a 20 percent solution was used as the tracer for all 10 time-of-travel studies. Water samples were collected at several points below each injection site. Concentrations of dye in the samples were measured by determining fluorescence of the sample and comparing that value to fluorescence-concentration curves. Stream discharges were measured before and during each study. Results of each time-by-travel study are shown on two tables and on graph. The first table shows water discharge at injection and sampling sites, distance between sites, and time and rate of travel of the dye between sites. The second table provides descriptions of study sites, amounts of dye injected in the streams, actual sampling times, and actual concentrations of dye detected. The graphs for each time-of-travel study provide indications of changing travel rates between sampling sites, information on length of dye clouds, and times for dye passage past given points. (USGS)

  5. Traveler's Health

    MedlinePlus

    ... water, boil it or use iodine tablets. Food poisoning can also be a risk. Eat only food that is fully cooked and served hot. Avoid unwashed or unpeeled raw fruits and vegetables. If you are traveling out of the country, ...

  6. Parallel tempering for the traveling salesman problem

    SciTech Connect

    Percus, Allon; Wang, Richard; Hyman, Jeffrey; Caflisch, Russel

    2008-01-01

    We explore the potential of parallel tempering as a combinatorial optimization method, applying it to the traveling salesman problem. We compare simulation results of parallel tempering with a benchmark implementation of simulated annealing, and study how different choices of parameters affect the relative performance of the two methods. We find that a straightforward implementation of parallel tempering can outperform simulated annealing in several crucial respects. When parameters are chosen appropriately, both methods yield close approximation to the actual minimum distance for an instance with 200 nodes. However, parallel tempering yields more consistently accurate results when a series of independent simulations are performed. Our results suggest that parallel tempering might offer a simple but powerful alternative to simulated annealing for combinatorial optimization problems.

  7. Travelers' Health: Cruise Ship Travel

    MedlinePlus

    ... provider before travel. Passengers should practice good respiratory hygiene and cough etiquette. Passengers should report their respiratory ... from: http://www.who.int/water_sanitation_health/hygiene/ships/en/shipsancomp.pdf?ua=1 . Chapter 6 - ...

  8. Actual Versus Estimated Utility Factor of a Large Set of Privately Owned Chevrolet Volts

    SciTech Connect

    John Smart; Thomas Bradley; Stephen Schey

    2014-04-01

    In order to determine the overall fuel economy of a plug-in hybrid electric vehicle (PHEV), the amount of operation in charge depleting (CD) versus charge sustaining modes must be determined. Mode of operation is predominantly dependent on customer usage of the vehicle and is therefore highly variable. The utility factor (UF) concept was developed to quantify the distance a group of vehicles has traveled or may travel in CD mode. SAE J2841 presents a UF calculation method based on data collected from travel surveys of conventional vehicles. UF estimates have been used in a variety of areas, including the calculation of window sticker fuel economy, policy decisions, and vehicle design determination. The EV Project, a plug-in electric vehicle charging infrastructure demonstration being conducted across the United States, provides the opportunity to determine the real-world UF of a large group of privately owned Chevrolet Volt extended range electric vehicles. Using data collected from Volts enrolled in The EV Project, this paper compares the real-world UF of two groups of Chevrolet Volts to estimated UF's based on J2841. The actual observed fleet utility factors (FUF) for the MY2011/2012 and MY2013 Volt groups studied were observed to be 72% and 74%, respectively. Using the EPA CD ranges, the method prescribed by J2841 estimates a FUF of 65% and 68% for the MY2011/2012 and MY2013 Volt groups, respectively. Volt drivers achieved higher percentages of distance traveled in EV mode for two reasons. First, they had fewer long-distance travel days than drivers in the national travel survey referenced by J2841. Second, they charged more frequently than the J2841 assumption of once per day - drivers of Volts in this study averaged over 1.4 charging events per day. Although actual CD range varied widely as driving conditions varied, the average CD ranges for the two Volt groups studied matched the EPA CD range estimates, so CD range variation did not affect FUF results.

  9. The stress of travel.

    PubMed

    Waterhouse, J; Reilly, T; Edwards, B

    2004-10-01

    International travel is an essential part of the life of elite athletes, both for competition and training. It is also becoming increasingly common among recreational sportspersons. Long-distance travel is associated with a group of transient negative effects, collectively referred to as 'travel fatigue', which result from anxiety about the journey, the change to an individual's daily routine, and dehydration due to time spent in the dry air of the aircraft cabin. Travel fatigue lasts for only a day or so, but for those who fly across several time zones, there are also the longer-lasting difficulties associated with 'jet lag'. The problems of jet lag can last for over a week if the flight crosses 10 time zones or more, and they can reduce performance and the motivation to train effectively. Knowledge of the properties of the body clock enables the cause of the difficulties to be understood (an unadjusted body clock), and forms the basis of using light in the new time zone to promote adjustment of the body clock. Sleep loss and its effects are important components of jet lag, and attempts to promote sleep by the use of melatonin and other hypnotics are also relevant. Sleep loss is also found in those who undertake challenges that involve long periods where the normal consolidated sleep of 8 h length is not possible. Advice on sleep regimens in such circumstances is given. PMID:15768727

  10. [Traveler's thrombosis].

    PubMed

    Riedel, M; Bohanes, V

    2002-08-01

    It is pathophysiologically conceivable that prolonged sitting in a tight space (e.g., in airplane or other transport vehicle) may lead to leg vein thrombosis. The association between the incidence of venous thromboembolism and long travel has not been sufficiently documented but seems probable. However, this association is only weak and the incidence of symptomatic thromboembolism much lower than the impression given by the recent publicity. In a healthy person, the risk of suffering a clinically relevant leg vein thrombosis solely because of a flight is extreme low. In persons with risk factors for venous thromboembolism, the flight represents an additional, as yet not quantifiable risk. This risk increases with the duration of the travel. The most important cause of thrombosis during long journeys seems to be venostasis due to relative immobilization. It is not clear whether flight travel represents a higher risk of thrombosis compared to other transport vehicles with comparable duration and immobilization. Until more exact information becomes available, it seems reasonable to recommend simple isometric and isotonic leg exercises during long travel. More aggressive measures must be considered for persons with risk factors for thromboembolism, but these measures should be individualized.

  11. Valuing coral reefs: a travel cost analysis of the Great Barrier Reef.

    PubMed

    Carr, Liam; Mendelsohn, Robert

    2003-08-01

    This study examines domestic and international travel to the Great Barrier Reef in order to estimate the benefits the reef provides to the 2 million visitors each year. The study explores the problems of functional form and of measuring travel cost for international visits: comparing actual costs, distance, and lowest price fares. The best estimates of the annual recreational benefits of the Great Barrier Reef range between USD 700 million to 1.6 billion. The domestic value to Australia is about USD 400 million, but the estimated value to more distant countries depends on the definition of travel cost and the functional form. The study conclusively demonstrates that there are very high benefits associated with protecting high quality coral reefs. PMID:14571965

  12. Travellers' diarrhoea.

    PubMed

    Arduino, R C; DuPont, H L

    1993-06-01

    Although TD is usually a mild and self-limited illness, 30-50% of travellers from industrialized to less developed countries are affected. Enterotoxigenic E. coli (ETEC) remain the most frequent cause, being identified in 40-70% of cases. TD frequently occurs within the first 2 weeks of arrival in the foreign country. The clinical manifestation is variable, but watery diarrhoea is the most common clinical presentation. Chronic diarrhoea or remitting symptoms after empirical therapy in the returning traveller are indications for a stool culture and a careful search for stool parasites. Since the major precaution against TD is to avoid exposure to the infectious agents, careful selection of food and beverage is crucial. Bismuth subsalicylate has been proven to be safe and effective in the treatment and prophylaxis of TD. The tablet form has removed the inconvenience of previously required luggage space. Doxycycline, trimethoprim/sulphamethoxazole, trimethoprim and the quinolones have been shown to be effective for prevention of diarrhoea. However, side-effects, superinfection, development of antibiotic resistance and easy-to-treat illness may limit the use of these antimicrobial agents to those travellers with concomitant serious medical conditions that would be adversely affected by diarrhoea, or travellers with unaffordable temporary incapacity. A new oral-killed whole-cell and B-subunit cholera toxin vaccine was demonstrated to induce protection against severe ETEC-associated diarrhoea. This is a promising field under investigation. Finally, fluid replacement is the most important aspect of treatment. Patients with moderate to severe TD can be treated with one of the above-mentioned antimicrobial agents for 3-5 days. Selection of the antimicrobial agent is based on the pattern of resistance and the enteric organism prevalent in the geographical area. While TMP-SMX remains active against the strains prevalent in Mexico during summertime, the quinolones represent

  13. [Immunocompromised travelers].

    PubMed

    Delmont, J; Igo-Kemenes, A; Peyron, F; Ruiz, J M; Moreau, J; Bourgeade, A

    1997-01-01

    More and more immunocompromised people travel abroad especially in tropical countries where infectious risks are high. Before leaving, these subjects must consult their general practitioner who will determine their fitness in function of type of immunodeficiency, travel destination, availability of medical care at the destination, and possibility of medical evacuation. Counseling should also be provided concerning the precautions necessary to avoid the hazards of exposure to fecal material, venereal disease, insect bites, and sun. Antimalarial drug prophylaxis is the same as for uncompromised subjects. Advising immunocompromised subjects about vaccinations is difficult since there is no consensus on the subject. Administration of inert vaccines is usually recommended but their effectiveness is often diminished and harmful effects have been observed in HIV-infected subjects. Administration of live vaccines is always contraindicated in severely immunocompromised subjects but some live vaccines can be used in moderately immunocompromised subjects. The guidelines for vaccination differ depending on the underlying cause of immunodeficiency: congenital defects, cancer, hemopathy, treatment with immunosuppressors or corticosteroids (transplant patients and patients with systemic disease), HIV-infection, or spleen dysfunction. If there is a high risk of contracting a disease for which vaccination is contraindicated, drug prophylaxis or administration of immunoglobulins can be an alternative. If not, travel should either be postponed or the destination should be changed.

  14. Travel Medical Kit.

    PubMed

    Terry, Anne C; Haulman, N Jean

    2016-03-01

    "The traveler's medical kit is an essential tool for both the novice and expert traveler. It is designed to treat travel-related illness and injury and to ensure preexisting medical conditions are managed appropriately. Travelers are at increased risk for common gastrointestinal issues during travel. Respiratory illnesses make up approximately 8% of the ailments present in returned international travelers. Approximately 12% of travelers experience a travel-related skin condition. First aid treatment for minor injuries is essential to all travel medical kits. The complexity ranges from a small, simple case for the urban traveler to a larger, extensive case for wilderness travel." PMID:26900112

  15. 77 FR 64430 - Federal Travel Regulation; Per Diem, Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... amounts from the meals and incidental expense (M&IE) reimbursement on travel days; extending agencies the... permits agencies to issue blanket actual expense authorizations for any employee who performs TDY travel... Case 2011-301; Docket 2011-0018, Sequence 1] RIN 3090-AJ11 Federal Travel Regulation; Per...

  16. 76 FR 55273 - Federal Travel Regulation; Per Diem, Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... agencies the authority to issue blanket actual expense approval for TDY travel during Presidentially.... PART 301-71--AGENCY TRAVEL ACCOUNTABILITY REQUIREMENTS 0 23. The authority citation for 41 CFR part 301... Case 2011-301; Docket 2011-0018, Sequence 1] RIN 3090-AJ11 Federal Travel Regulation; Per...

  17. 19 CFR 123.62 - Baggage in possession of traveler.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Baggage in possession of traveler. 123.62 Section... OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Baggage § 123.62 Baggage in possession of traveler. For baggage arriving in the actual possession of a traveler, his declaration shall be accepted...

  18. 33 CFR 5.57 - Traveling expenses and per diem.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Traveling expenses and per diem... GENERAL COAST GUARD AUXILIARY § 5.57 Traveling expenses and per diem. A member of the Auxiliary, when assigned to specific duties, may be paid actual necessary traveling expenses, including a per...

  19. 33 CFR 5.57 - Traveling expenses and per diem.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Traveling expenses and per diem... GENERAL COAST GUARD AUXILIARY § 5.57 Traveling expenses and per diem. A member of the Auxiliary, when assigned to specific duties, may be paid actual necessary traveling expenses, including a per...

  20. Home range and travels

    USGS Publications Warehouse

    Stickel, L.F.; King, John A.

    1968-01-01

    . Peromyscus generally used and maintained several or many different home sites and refuges in various parts of their home ranges, and frequently shifted about so that their principal activities centered on different sets of holes at different times. Once established, many Peromyscus remained in the same general area for a long time, perhaps for the duration of their lives. Extent of their travels in different directions and intensity of use of different portions of their home ranges varied within a general area in response to habitat changes, loss of neighbors, or other factors. Various authors have obtained both direct and indirect evidence of territoriality, in some degree, among certain species of Peromyscus. Young mice dispersed from their birth sites to establish home ranges of their own. Adults also sometimes left their home areas; some re-established elsewhere; others returned after exploratory travels. Most populations contained a certain proportion of transients; these may have been wanderers or individuals exploring out from established home ranges or seeking new ones. When areas were depopulated by removal trapping, other Peromyscus invaded. Invasion rates generally followed seasonal trends of reproduction and population density. Peromyscus removed from their home areas and released elsewhere returned home from various distances, but fewer returned from greater distances than from nearby; speed of return increased with successive trials. The consensus from present evidence is that ho-ming is made possible by a combination of random wandering and familiarity with a larger area than the day-to-day range. Records of juvenile wanderings during the dispersal phase and of adult explorations very nearly encompassed the distances over which any substantial amount of successful homing occurred. Methods of measuring sizes of home ranges and the limitations of these measurements were discussed in brief synopsis. It was co

  1. Form and Actuality

    NASA Astrophysics Data System (ADS)

    Bitbol, Michel

    A basic choice underlies physics. It consists of banishing actual situations from theoretical descriptions, in order to reach a universal formal construct. Actualities are then thought of as mere local appearances of a transcendent reality supposedly described by the formal construct. Despite its impressive success, this method has left major loopholes in the foundations of science. In this paper, I document two of these loopholes. One is the problem of time asymmetry in statistical thermodynamics, and the other is the measurement problem of quantum mechanics. Then, adopting a broader philosophical standpoint, I try to turn the whole picture upside down. Here, full priority is given to actuality (construed as a mode of the immanent reality self-reflectively being itself) over formal constructs. The characteristic aporias of this variety of "Copernican revolution" are discussed.

  2. Travel Advice for Higher Functioning Individuals on the Autism Spectrum

    ERIC Educational Resources Information Center

    VanBergeijk, Ernst

    2009-01-01

    While travel training on local mass transit makes intuitive sense, the thought of larger scale travel training does not occur to most people. Possible benefits that could be gained from long distance or more involved traveling with individuals on the autism spectrum are vast. In this article, the author presents 11 essential skills that are a…

  3. Vaccinations for international travellers travelling from Greece.

    PubMed

    Pavli, Androula; Spilioti, Athina; Lymperi, Ioanna; Katerelos, Panagiotis; Maltezou, Helena C

    2013-01-01

    The aim of this prospective, questionnaire-based study is to assess pre-travel vaccinations for international travellers who receive pre-travel advice in Greece. A total of 2494 travellers were studied from January 1, 2009 through December 31, 2010. Travellers sought pre-travel advice at a median of 16 days (range: 0-349 days) before departure. Sub-Saharan Africa was the most common destination (34.7%). Most travellers (60.8%) travelled for <1 month, for recreation purposes (58.9%), stayed in hotels (65.3%), and in urban areas (53.6%). Yellow fever, tetravalent meningococcal, typhoid fever, cholera, and rabies vaccines were administered to 1629 (65.3%), 666 (26.7%), 615 (24.7%), 28 (1.1%), and/or 12 (0.5%) travellers, respectively. Of those who received Yellow fever vaccine, 737 (45.2%) travelled to sub-Saharan Africa, 332 (20.4%) travelled to South America, 949 (58.3%) stayed for short term, and 762 (46.8%) stayed in urban areas. Of the 1629 travellers vaccinated against Yellow fever, 150 (9.2%) and 226 (13.8%) travelled to areas of sub-Saharan Africa and South America respectively, where the vaccine is not or generally not recommended. Of those travellers who received meningococcal vaccine, 327 (49.1%) travelled to the Middle East for the Hajj, 251 (29%) travelled to sub-Saharan Africa, 410 (61.6%) for short term, and 540 (64.4%) stayed in urban areas. Of those travellers who received typhoid vaccine, 241 (39.2%) travelled to sub-Saharan Africa, 78 (12.7%) to the Indian subcontinent, 234 (38%) for short term, and 419 (68.1%) stayed in urban areas. Regarding routine vaccines, tetanus-diphtheria, poliomyelitis, and measles-mumps-rubella vaccines were administered to 707 (28.3%), 639 (25.6%) and/or 149 (6%) travellers, respectively. Of those to whom poliomyelitis vaccine was recommended, 295 (46.2%) and 137 (21.4%) travelled to sub-Saharan Africa and the Middle East, respectively, and 362 (56.7%) travelled for short term. In conclusion, this study revealed that

  4. Traveling baseball players' problem in Korea

    NASA Astrophysics Data System (ADS)

    Jeong, Hyang Min; Kim, Sang-Woo; Choi, Younguk; Kim, Aaram J.; Eun, Jonghyoun; Kim, Beom Jun

    2012-08-01

    We study the so-called traveling tournament problem (TTP) to find an optimal tournament schedule. Differently from the original TTP, in which the total travel distance of all the participants is the objective function to minimize, we instead seek to maximize the fairness of the round robin tournament schedule of the Korean Baseball League. The standard deviation of the travel distances of teams is defined as the energy function, and the Metropolis Monte-Carlo method combined with the simulated annealing technique is applied to find the ground-state configuration. The resulting tournament schedule is found to satisfy all the constraint rules set by the Korean Baseball Organization, but with drastically increased fairness in traveling distances.

  5. Simulation Distances

    NASA Astrophysics Data System (ADS)

    Černý, Pavol; Henzinger, Thomas A.; Radhakrishna, Arjun

    Boolean notions of correctness are formalized by preorders on systems. Quantitative measures of correctness can be formalized by real-valued distance functions between systems, where the distance between implementation and specification provides a measure of "fit" or "desirability." We extend the simulation preorder to the quantitative setting, by making each player of a simulation game pay a certain price for her choices. We use the resulting games with quantitative objectives to define three different simulation distances. The correctness distance measures how much the specification must be changed in order to be satisfied by the implementation. The coverage distance measures how much the implementation restricts the degrees of freedom offered by the specification. The robustness distance measures how much a system can deviate from the implementation description without violating the specification. We consider these distances for safety as well as liveness specifications. The distances can be computed in polynomial time for safety specifications, and for liveness specifications given by weak fairness constraints. We show that the distance functions satisfy the triangle inequality, that the distance between two systems does not increase under parallel composition with a third system, and that the distance between two systems can be bounded from above and below by distances between abstractions of the two systems. These properties suggest that our simulation distances provide an appropriate basis for a quantitative theory of discrete systems. We also demonstrate how the robustness distance can be used to measure how many transmission errors are tolerated by error correcting codes.

  6. Travelers' Health: Water Disinfection for Travelers

    MedlinePlus

    ... be superior to tap water. Moreover, the plastic bottles create an ecological problem, since most developing countries do not recycle plastic bottles. All international travelers, especially long-term travelers or ...

  7. Distance Education.

    ERIC Educational Resources Information Center

    ASPBAE Courier, 1984

    1984-01-01

    This publication is devoted to distance education. "The Future of Distance Teaching Universities in a Worldwide Perspectives" (John S. Daniel) examines challenges likely to face the various countries and regions of the world in the next decade. "An Australian University's Approach to Distance Education--Formal and Non-Formal" (Peter M. Grayson)…

  8. Mental travel: some reservations.

    PubMed

    Richman, C L; Mitchell, D B; Reznick, J S

    1979-02-01

    Two experiments were conducted to assess the extent of potential experimental demand characteristics inherent in the image-scanning paradigm. The results of the first "mental travel" experiment that pitted verbal versus imagery coding showed that (a) the positive correlation between physical distance and reaction time was replicated, and (b) when given a choice, subjects' reaction times varied as a function of verbal codes rather than imagery. To isolate the effects due to demand constraints from those produced by mode dominance, a nonexperiment in which subjects received only a description of the image-scanning procedure was conducted. Results demonstrated that subjects were capable of predicting the reaction time results for both verbal and imagery codes. The presence of experimental demand in the image-scanning paradigm necessitates caution when structural interpretations of visual images are considered.

  9. Health, sustainability and student travel.

    PubMed

    Green, Gill; Morris, Jenny; Wade, Margaret

    2012-01-01

    A survey of 246 pre-registration nursing students in a University in the South West of England was carried out to explore the impact of course related travel on the student experience. Results from the survey indicated that students' main mode of transport to practice placements was by car which reflects the rural nature of the South West and the relative paucity of public transport. Long distances that many students travel to their study centre and to placements, and the concurrent financial strain that this creates, impacted negatively on the student experience. Students recognised the need to travel to a place of study and clinical placements and suggestions of minimising the negative impact of travel were offered. These included the increased use of electronic delivery of lectures, attendance at local university premises, the provision of shared transport to placements and placements closer to the student's home. Few students, however, considered the environmental impact of travel. Higher Education Institutions need to address issues of sustainability through promoting student wellbeing and taking steps to reduce greenhouse gas emissions. It is therefore important that student awareness of sustainability related issues is increased as well as focusing on reducing the environmental impact through organisational change.

  10. Travel fosters tool use in wild chimpanzees.

    PubMed

    Gruber, Thibaud; Zuberbühler, Klaus; Neumann, Christof

    2016-01-01

    Ecological variation influences the appearance and maintenance of tool use in animals, either due to necessity or opportunity, but little is known about the relative importance of these two factors. Here, we combined long-term behavioural data on feeding and travelling with six years of field experiments in a wild chimpanzee community. In the experiments, subjects engaged with natural logs, which contained energetically valuable honey that was only accessible through tool use. Engagement with the experiment was highest after periods of low fruit availability involving more travel between food patches, while instances of actual tool-using were significantly influenced by prior travel effort only. Additionally, combining data from the main chimpanzee study communities across Africa supported this result, insofar as groups with larger travel efforts had larger tool repertoires. Travel thus appears to foster tool use in wild chimpanzees and may also have been a driving force in early hominin technological evolution. PMID:27431611

  11. 10 CFR 719.43 - What is the treatment of travel costs?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-46, as appropriate, to be reimbursable. (b) Travel time may be allowed at a full hourly rate for the... remaining travel time shall be reimbursed at 50 percent of the full hourly rate, except that in no event will travel time spent working for other clients be allowable. Also, for long distance travel...

  12. Childhood and Travel Literature.

    ERIC Educational Resources Information Center

    Espey, David

    If children are not present in most travel literature--precisely because the genre has most typically been the domain of solitary male travelers who are escaping domestic obligation, routine, the familiar, and the family--they nevertheless are an integral part of the genre. The traveler is in many ways a child, an innocent abroad. Traveler writers…

  13. Travel-related illness.

    PubMed

    Ziegler, Carol C

    2013-06-01

    Travel abroad for business and pleasure should be safe and meaningful for the traveler. To assure that safe experience, certain processes should be considered before travel. A thorough pretravel health assessment will offer patients and health care providers valuable information for anticipatory guidance before travel. The destination-based risk assessment will help determine the risks involved in travel to specific locations and guide in the development of contingency plans for all travelers, especially those with chronic conditions. Diseases are more prevalent overseas, and immunizations and vaccinations are all important considerations for persons traveling abroad.

  14. Secure distance ranging by electronic means

    DOEpatents

    Gritton, Dale G.

    1992-01-01

    A system for secure distance ranging between a reader 11 and a tag 12 wherein the distance between the two is determined by the time it takes to propagate a signal from the reader to the tag and for a responsive signal to return, and in which such time is random and unpredictable, except to the reader, even though the distance between the reader and tag remains the same. A random number (19) is sent from the reader and encrypted (26) by the tag into a number having 16 segments of 4 bits each (28). A first tag signal (31) is sent after such encryption. In response, a random width start pulse (13) is generated by the reader. When received in the tag, the width of the start pulse is measured (41) in the tag and a segment of the encrypted number is selected (42) in accordance with such width. A second tag pulse is generated at a time T after the start pulse arrives at the tag, the time T being dependent on the length of a variable time delay t.sub.v which is determined by the value of the bits in the selected segment of the encrypted number. At the reader, the total time from the beginning of the start pulse to the receipt of the second tag signal is measured (36, 37). The value of t.sub.v (21, 22, 23, 34) is known at the reader and the time T is subtracted (46) from the total time to find the actual propagation t.sub.p for signals to travel between the reader 11 and tag 12. The propagation time is then converted into distance (46).

  15. Rabies in travelers.

    PubMed

    Gautret, Philippe; Parola, Philippe

    2014-03-01

    Most cases of rabies in travelers are associated with dog bites and occur in adults who are commonly migrants. The incidence of injuries to travelers caused by potentially rabid animals is approximately 0.4 % per month of stay. Dogs account for 51 % of cases, but nonhuman primates are the leading animals responsible for injuries in travelers returning from Southeast Asia. Travel to Southeast Asia, India and North Africa, young age, and traveling for tourism are risk factors for potential exposure. More than 70 % of travelers are not immunized prior to departing and do not receive adequate care when injured. The intradermal vaccination route has been proven economical, safe and immunogenic in travelers. The immunity provided by the three-dose series is long-lasting and should be considered an investment for future travel. Abbreviated schedules may be used for last-minute travelers. PMID:24562541

  16. 41 CFR 302-4.304 - For relocation outside the continental United States (OCONUS), may my agency allow actual expense...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...), may my agency allow actual expense reimbursement instead of the POV mileage rate for PCS travel? Yes... the continental United States (OCONUS), may my agency allow actual expense reimbursement instead of the POV mileage rate for PCS travel? 302-4.304 Section 302-4.304 Public Contracts and...

  17. 41 CFR 302-4.304 - For relocation outside the continental United States (OCONUS), may my agency allow actual expense...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...), may my agency allow actual expense reimbursement instead of the POV mileage rate for PCS travel? Yes... the continental United States (OCONUS), may my agency allow actual expense reimbursement instead of the POV mileage rate for PCS travel? 302-4.304 Section 302-4.304 Public Contracts and...

  18. Gibbon travel paths are goal oriented.

    PubMed

    Asensio, Norberto; Brockelman, Warren Y; Malaivijitnond, Suchinda; Reichard, Ulrich H

    2011-05-01

    Remembering locations of food resources is critical for animal survival. Gibbons are territorial primates which regularly travel through small and stable home ranges in search of preferred, limited and patchily distributed resources (primarily ripe fruit). They are predicted to profit from an ability to memorize the spatial characteristics of their home range and may increase their foraging efficiency by using a 'cognitive map' either with Euclidean or with topological properties. We collected ranging and feeding data from 11 gibbon groups (Hylobates lar) to test their navigation skills and to better understand gibbons' 'spatial intelligence'. We calculated the locations at which significant travel direction changes occurred using the change-point direction test and found that these locations primarily coincided with preferred fruit sources. Within the limits of biologically realistic visibility distances observed, gibbon travel paths were more efficient in detecting known preferred food sources than a heuristic travel model based on straight travel paths in random directions. Because consecutive travel change-points were far from the gibbons' sight, planned movement between preferred food sources was the most parsimonious explanation for the observed travel patterns. Gibbon travel appears to connect preferred food sources as expected under the assumption of a good mental representation of the most relevant sources in a large-scale space.

  19. Gibbon travel paths are goal oriented.

    PubMed

    Asensio, Norberto; Brockelman, Warren Y; Malaivijitnond, Suchinda; Reichard, Ulrich H

    2011-05-01

    Remembering locations of food resources is critical for animal survival. Gibbons are territorial primates which regularly travel through small and stable home ranges in search of preferred, limited and patchily distributed resources (primarily ripe fruit). They are predicted to profit from an ability to memorize the spatial characteristics of their home range and may increase their foraging efficiency by using a 'cognitive map' either with Euclidean or with topological properties. We collected ranging and feeding data from 11 gibbon groups (Hylobates lar) to test their navigation skills and to better understand gibbons' 'spatial intelligence'. We calculated the locations at which significant travel direction changes occurred using the change-point direction test and found that these locations primarily coincided with preferred fruit sources. Within the limits of biologically realistic visibility distances observed, gibbon travel paths were more efficient in detecting known preferred food sources than a heuristic travel model based on straight travel paths in random directions. Because consecutive travel change-points were far from the gibbons' sight, planned movement between preferred food sources was the most parsimonious explanation for the observed travel patterns. Gibbon travel appears to connect preferred food sources as expected under the assumption of a good mental representation of the most relevant sources in a large-scale space. PMID:21221693

  20. 11 CFR 9004.7 - Allocation of travel expenditures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... campaign purposes. (ii) If the trip is by non-charter commercial transportation, the actual cost shall be... travel expenditures. (a) Notwithstanding the provisions of 11 CFR 106.3, expenditures for travel relating... be reported by the candidate's authorized committee(s) as expenditures. (b)(1) For a trip which...

  1. 11 CFR 9004.7 - Allocation of travel expenditures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... campaign purposes. (ii) If the trip is by non-charter commercial transportation, the actual cost shall be... travel expenditures. (a) Notwithstanding the provisions of 11 CFR 106.3, expenditures for travel relating... be reported by the candidate's authorized committee(s) as expenditures. (b)(1) For a trip which...

  2. 11 CFR 9034.7 - Allocation of travel expenditures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... traveling for campaign purposes. (ii) If the trips is by non-charter commercial transportation, the actual... the provisions of 11 CFR 106.3, expenditures for travel relating to the campaign of a candidate... by the candidate's authorized committee(s) as expenditures. (b)(1) For a trip which is...

  3. 11 CFR 9034.7 - Allocation of travel expenditures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... traveling for campaign purposes. (ii) If the trips is by non-charter commercial transportation, the actual... the provisions of 11 CFR 106.3, expenditures for travel relating to the campaign of a candidate... by the candidate's authorized committee(s) as expenditures. (b)(1) For a trip which is...

  4. 11 CFR 9004.7 - Allocation of travel expenditures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... campaign purposes. (ii) If the trip is by non-charter commercial transportation, the actual cost shall be... travel expenditures. (a) Notwithstanding the provisions of 11 CFR 106.3, expenditures for travel relating... be reported by the candidate's authorized committee(s) as expenditures. (b)(1) For a trip which...

  5. 11 CFR 9034.7 - Allocation of travel expenditures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... traveling for campaign purposes. (ii) If the trips is by non-charter commercial transportation, the actual... the provisions of 11 CFR 106.3, expenditures for travel relating to the campaign of a candidate... by the candidate's authorized committee(s) as expenditures. (b)(1) For a trip which is...

  6. A preliminary study on activity budget, daily travel distance and feeding behaviour of long-tailed macaques and spectacled dusky leaf monkey in Bangi campus of Universiti Kebangsaan Malaysia, Selangor

    NASA Astrophysics Data System (ADS)

    Ruslin, Farhani; Yaakop, Salmah; Zain, Badrul Munir Md.

    2014-09-01

    The activity budget, ranging behaviour and feeding behaviour of a multimale-multifemale group of long-tailed macaques (Macaca fascicularis) and a multimale-multifemale group of spectacled dusky leaf monkey (Trachypithecus obscurus) were studied. A total of 145 hours and 143 hours have been spent to observe the group of long-tailed macaque and spectacled dusky leaf monkey that ranged the same habitat adjacent to the campus areas. The researchers examined the activity budgets, daily travel length and feeding activity of both species and distinguished how the sympatric species used the same forested habitat. Preliminary study found that the long-tailed macaques spent longer time feeding, moving than resting and other activities. On the other hand, the dusky leaf monkey spent much time in feeding and resting than moving. The differences of daily pattern between these two groups are significant. Macaques have higher daily mean of path length compared to the dusky leaf monkey and spent much time moving compare to the leaf monkey group. The spectacled dusky leaf monkey group also has fully utilized the forested areas where else the long-tailed macaques adopted foraging to the adjacent residential colleges.

  7. Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.

    2010-01-01

    Time-distance helioseismology is a method of ambient noise imaging using the solar oscillations. The basic realization that led to time-distance helioseismology was that the temporal cross correlation of the signals at two 'surface' (or photospheric) locations should show a feature at the time lag corresponding to the subsurface travel time between the locations. The temporal cross correlation, as a function of the location separation, is the Fourier transform of the spatio-temporal power spectrum of the solar oscillations, a commonly used function in helioseismology. It is therefore likely the characteristic ridge structure of the correlation function had been seen before without appreciation of its significance. Travel times are measured from the cross correlations. The times are sensitive to a number of important subsurface solar phenomena. These include sound speed variations, flows, and magnetic fields. There has been much interesting progress in the 17 years since the first paper on this subject (Duvall et al., Nature, 1993, 362, 430-432). This progress will be reviewed in this paper.

  8. Minimizing travel claims cost with minimal-spanning tree model

    NASA Astrophysics Data System (ADS)

    Jamalluddin, Mohd Helmi; Jaafar, Mohd Azrul; Amran, Mohd Iskandar; Ainul, Mohd Sharizal; Hamid, Aqmar; Mansor, Zafirah Mohd; Nopiah, Zulkifli Mohd

    2014-06-01

    Travel demand necessitates a big expenditure in spending, as has been proven by the National Audit Department (NAD). Every year the auditing process is carried out throughout the country involving official travel claims. This study focuses on the use of the Spanning Tree model to determine the shortest path to minimize the cost of the NAD's official travel claims. The objective is to study the possibility of running a network based in the Kluang District Health Office to eight Rural Clinics in Johor state using the Spanning Tree model applications for optimizing travelling distances and make recommendations to the senior management of the Audit Department to analyze travelling details before an audit is conducted. Result of this study reveals that there were claims of savings of up to 47.4% of the original claims, over the course of the travel distance.

  9. Travelers' Health: Leishmaniasis, Visceral

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Infected travelers should be advised to consult an infectious disease or tropical medicine specialist. Therapy for VL should ...

  10. Travelers' Health: HIV Infection

    MedlinePlus

    ... 448-4911 ( www.nccc.ucsf.edu ). HIV TESTING REQUIREMENTS FOR US TRAVELERS ENTERING FOREIGN COUNTRIES International travelers ... extended stay should review that country’s policies and requirements. This information is usually available from the consular ...

  11. Zika Travel Information

    MedlinePlus

    ... Citizens and Residents Living in Areas with Ongoing Zika Virus Transmission Guidelines for Travelers Visiting Friends and Family ... with Zika . For the most current information about Zika virus, please visit CDC’s Zika website . Traveling soon? Get ...

  12. A comparison of actual and perceived residential proximity to toxic waste sites.

    PubMed

    Howe, H L

    1988-01-01

    Studies of Memphis and Three Mile Island have noted a positive association between actual residential distance and public concern about exposure to the potential of contamination, whereas none was found at Love Canal. In this study, concern about environmental contamination and exposure was examined in relation to both perceived and actual proximity to a toxic waste disposal site (TWDS). It was hypothesized that perceived residential proximity would better predict concern levels that would actual residential distance. The data were abstracted from a New York State, excluding New York City, survey using all respondents (N = 317) from one county known to have a large number of TWDSs. Using linear regression, the variance explained in concern scores was 22 times higher with perceived distance than for actual distance. Perceived residential distance was a significant predictor of concern scores, while actual distance was not. However, perceived distance explained less than 5% of the variance in concern scores. PMID:3196077

  13. Travel Agent Course Outline.

    ERIC Educational Resources Information Center

    British Columbia Dept. of Education, Victoria.

    Written for college entry-level travel agent training courses, this course outline can also be used for inservice training programs offered by travel agencies. The outline provides information on the work of a travel agent and gives clear statements on what learners must be able to do by the end of their training. Material is divided into eight…

  14. Air Travel Health Tips

    MedlinePlus

    MENU Return to Web version Air Travel Health Tips Air Travel Health Tips How can I improve plane travel? Most people don't have any problems when ... and dosages of all of your medicines. The air in airplanes is dry, so drink nonalcoholic, decaffeinated ...

  15. The Jet Travel Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2007-01-01

    Airplane travelers are dismayed by the long lines and seemingly chaotic activities that precede boarding a full airplane. Surely, the one who can solve this problem is going to make many travelers happy. This article describes the Jet Travel Challenge, an activity that challenges students to create some alternatives to this now frustrating…

  16. Genetic drift and the population history of the Irish travellers.

    PubMed

    Relethford, John H; Crawford, Michael H

    2013-02-01

    The Irish Travellers are an itinerant group in Ireland that has been socially isolated. Two hypotheses have been proposed concerning the genetic origin of the Travellers: (1) they are genetically related to Roma populations in Europe that share a nomadic lifestyle or (2) they are of Irish origin, and genetic differences from the rest of Ireland reflect genetic drift. These hypotheses were tested using data on 33 alleles from 12 red blood cell polymorphism loci. Comparison with other European, Roma, and Indian populations shows that the Travellers are genetically distinct from the Roma and Indian populations and most genetically similar to Ireland, in agreement with earlier genetic analyses of the Travellers. However, the Travellers are still genetically distinct from other Irish populations, which could reflect some external gene flow and/or the action of genetic drift in a small group that was descended from a small number of founders. In order to test the drift hypothesis, we analyzed genetic distances comparing the Travellers to four geographic regions in Ireland. These distances were then compared with adjusted distances that account for differential genetic drift using a method developed by Relethford (Hum Biol 68 (1996) 29-44). The unadjusted distances show the genetic distinctiveness of the Travellers. After adjustment for the expected effects of genetic drift, the Travellers are equidistant from the other Irish samples, showing their Irish origins and population history. The observed genetic differences are thus a reflection of genetic drift, and there is no evidence of any external gene flow. PMID:23180293

  17. Genetic drift and the population history of the Irish travellers.

    PubMed

    Relethford, John H; Crawford, Michael H

    2013-02-01

    The Irish Travellers are an itinerant group in Ireland that has been socially isolated. Two hypotheses have been proposed concerning the genetic origin of the Travellers: (1) they are genetically related to Roma populations in Europe that share a nomadic lifestyle or (2) they are of Irish origin, and genetic differences from the rest of Ireland reflect genetic drift. These hypotheses were tested using data on 33 alleles from 12 red blood cell polymorphism loci. Comparison with other European, Roma, and Indian populations shows that the Travellers are genetically distinct from the Roma and Indian populations and most genetically similar to Ireland, in agreement with earlier genetic analyses of the Travellers. However, the Travellers are still genetically distinct from other Irish populations, which could reflect some external gene flow and/or the action of genetic drift in a small group that was descended from a small number of founders. In order to test the drift hypothesis, we analyzed genetic distances comparing the Travellers to four geographic regions in Ireland. These distances were then compared with adjusted distances that account for differential genetic drift using a method developed by Relethford (Hum Biol 68 (1996) 29-44). The unadjusted distances show the genetic distinctiveness of the Travellers. After adjustment for the expected effects of genetic drift, the Travellers are equidistant from the other Irish samples, showing their Irish origins and population history. The observed genetic differences are thus a reflection of genetic drift, and there is no evidence of any external gene flow.

  18. Student Travel: Policies - Regulations - Exhibits.

    ERIC Educational Resources Information Center

    Trujillo, Lorenzo A.; And Others

    The Jefferson County (Colorado) Public Schools' regulations and policies concerning student travel covers these forms of travel: student activity travel, extended student travel, district sponsored student travel, district authorized student travel, student exchange, and bonus learning trips. Issues and items addressed include: (1) authorization…

  19. Regular transport dynamics produce chaotic travel times

    NASA Astrophysics Data System (ADS)

    Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Johnson, Neil F.; Toledo, Benjamín; Valdivia, Juan Alejandro

    2014-06-01

    In the hope of making passenger travel times shorter and more reliable, many cities are introducing dedicated bus lanes (e.g., Bogota, London, Miami). Here we show that chaotic travel times are actually a natural consequence of individual bus function, and hence of public transport systems more generally, i.e., chaotic dynamics emerge even when the route is empty and straight, stops and lights are equidistant and regular, and loading times are negligible. More generally, our findings provide a novel example of chaotic dynamics emerging from a single object following Newton's laws of motion in a regularized one-dimensional system.

  20. Regular transport dynamics produce chaotic travel times.

    PubMed

    Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Johnson, Neil F; Toledo, Benjamín; Valdivia, Juan Alejandro

    2014-06-01

    In the hope of making passenger travel times shorter and more reliable, many cities are introducing dedicated bus lanes (e.g., Bogota, London, Miami). Here we show that chaotic travel times are actually a natural consequence of individual bus function, and hence of public transport systems more generally, i.e., chaotic dynamics emerge even when the route is empty and straight, stops and lights are equidistant and regular, and loading times are negligible. More generally, our findings provide a novel example of chaotic dynamics emerging from a single object following Newton's laws of motion in a regularized one-dimensional system.

  1. Advances in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.; Beck, John G.; Gizon, Laurent; Kosovichev, Alexander F.; Oegerle, William (Technical Monitor)

    2002-01-01

    Time-distance helioseismology is a way to measure travel times between surface locations for waves traversing the solar interior. Coupling the travel with an extensive modeling effort has proven to be a powerful tool for measuring flows and other wave speed inhomogeneities in the solar interior. Problems receiving current attention include studying the time variation of the meridional circulation and torsional oscillation and active region emergence and evolution, current results on these topics will be presented.

  2. [Vaccination for international travelers].

    PubMed

    Arrazola, M Pilar; Serrano, Almudena; López-Vélez, Rogelio

    2016-05-01

    Traveler's vaccination is one of the key strategies for the prevention of infectious diseases during international travel. The risk of acquiring an infectious disease is determined in each case by the characteristics of the traveler and the travel, so the pre-departure medical advice of the traveler must be individualized. The World Health Organization classifies travelerś vaccines into three groups. - Vaccines for routine use in national immunization programs: Haemophilus influenzae type b, hepatitis B, polio, measles-mumps-rubella, tetanus-diphtheria-whooping a cough, and chickenpox. - Vaccinations required by law in certain countries before to enter them: yellow fever, meningococcal disease and poliomyelitis. - Vaccines recommended depending on the circumstances: cholera, japanese encephalitis, tick-borne encephalitis, meningococcal disease, typhoid fever, influenza, hepatitis A, hepatitis B, rabies and BCG. This review is intended to introduce the reader to the field of international vaccination.

  3. [Vaccination for international travelers].

    PubMed

    Arrazola, M Pilar; Serrano, Almudena; López-Vélez, Rogelio

    2016-05-01

    Traveler's vaccination is one of the key strategies for the prevention of infectious diseases during international travel. The risk of acquiring an infectious disease is determined in each case by the characteristics of the traveler and the travel, so the pre-departure medical advice of the traveler must be individualized. The World Health Organization classifies travelerś vaccines into three groups. - Vaccines for routine use in national immunization programs: Haemophilus influenzae type b, hepatitis B, polio, measles-mumps-rubella, tetanus-diphtheria-whooping a cough, and chickenpox. - Vaccinations required by law in certain countries before to enter them: yellow fever, meningococcal disease and poliomyelitis. - Vaccines recommended depending on the circumstances: cholera, japanese encephalitis, tick-borne encephalitis, meningococcal disease, typhoid fever, influenza, hepatitis A, hepatitis B, rabies and BCG. This review is intended to introduce the reader to the field of international vaccination. PMID:26920587

  4. Travel trends and energy

    SciTech Connect

    Corsi, T.M.; Harvey, M.E.

    1980-04-01

    Available data sources are utilized to construct scenarios of adjustment patterns in vacation/recreation travel as affected by both past and prospective fuel price and availability developments. The increases in gasoline prices coupled with supply uncertainties that occurred during the 1970's have strained the traditional vacation patterns of many U.S. households. New travel patterns will prompt changes in the location of outdoor recreation centers/ such centers will be located closer to major population centers to shorten travel time.

  5. Prevention of traveler's diarrhea.

    PubMed

    Tellier, R; Keystone, J S

    1992-06-01

    Preventing traveler's diarrhea is usually a matter of common sense, good luck, and the host's ability to defend against enteric pathogens, particularly enterotoxigenic Escherichia coli. Untreated tap water, ice cubes, unpasteurized milk products, salads, food from street vendors, and dining in unhygienic-appearing restaurants should be avoided. Well-cooked food that is served hot and carbonated, commercially bottled beverages are usually safe. Food and water precautions, however, are no guarantee of success in preventing traveler's diarrhea. Bismuth subsalicylate used prophylactically is somewhat inconvenient and is only moderately effective. Although antibiotic prophylaxis is very effective for traveler's diarrhea, particularly the quinolones, it should be reserved for high-risk travelers. PMID:1624780

  6. Malaria Risk in Travelers

    PubMed Central

    Askling, Helena Hervius; Nilsson, Jenny; Tegnell, Anders; Janzon, Ragnhild

    2005-01-01

    Imported malaria has been an increasing problem in several Western countries in the last 2 decades. To calculate the risk factors of age, sex, and travel destination in Swedish travelers, we used data from the routine reporting system for malaria (mixture of patients with and without adequate prophylaxis), a database on travel patterns, and in-flight or visa data on Swedish travelers of 1997 to 2003. The crude risk for travelers varied from 1 per 100,000 travelers to Central America and the Caribbean to 357 per 100,000 in central Africa. Travelers to East Africa had the highest adjusted odds ratio (OR = 341; 95% confidence intervals [CI] 134–886) for being reported with malaria, closely followed by travelers to central Africa and West Africa. Male travelers as well as children <1–6 years of age had a higher risk of being reported with malaria (OR = 1,7; 95% CI 1.3–2.3 and OR = 4,8; 95%CI 1.5–14.8) than women and other age groups. PMID:15757560

  7. [Travel and venous thromboembolism].

    PubMed

    Hallundbæk Mikkelsen, Kristian; Knudsen, Stine Ulrik; Nannestad Jørgensen, Lars

    2013-10-28

    A literature study on the association between travel and venous thromboembolism (VTE) is conducted. Studies examining the risk of travel-associated VTE, predisposing factors and prophylactic measures are presented. It is concluded that the absolute risk of travel-associated VTE is low and holds a 2-4 fold increase after travel. The risk increases with duration, presence of other risk factors for VTE and extremes of height. Stockings reduces the risk of asymptomatic VTE. Heparin is presumed to constitute protection whereas there is no evidence of a prophylactic effect of acetylsalicylic acid.

  8. Pre-Travel Medical Preparation of Business and Occupational Travelers

    PubMed Central

    Khan, Nomana M.; Jentes, Emily S.; Brown, Clive; Han, Pauline; Rao, Sowmya R.; Kozarsky, Phyllis; Hagmann, Stefan H.F.; LaRocque, Regina C.; Ryan, Edward T.

    2016-01-01

    Objectives: The aim of the study was to understand more about pre-travel preparations and itineraries of business and occupational travelers. Methods: De-identified data from 18 Global TravEpiNet clinics from January 2009 to December 2012 were analyzed. Results: Of 23,534 travelers, 61% were non-occupational and 39% occupational. Business travelers were more likely to be men, had short times to departure and shorter trip durations, and commonly refused influenza, meningococcal, and hepatitis B vaccines. Most business travelers indicated that employers suggested the pre-travel health consultation, whereas non-occupational travelers sought consultations because of travel health concerns. Conclusions: Sub-groups of occupational travelers have characteristic profiles, with business travelers being particularly distinct. Employers play a role in encouraging business travelers to seek pre-travel consultations. Such consultations, even if scheduled immediately before travel, can identify vaccination gaps and increase coverage. PMID:26479857

  9. The scaling laws of human travel

    NASA Astrophysics Data System (ADS)

    Brockmann, D.; Hufnagel, L.; Geisel, T.

    2006-01-01

    The dynamic spatial redistribution of individuals is a key driving force of various spatiotemporal phenomena on geographical scales. It can synchronize populations of interacting species, stabilize them, and diversify gene pools. Human travel, for example, is responsible for the geographical spread of human infectious disease. In the light of increasing international trade, intensified human mobility and the imminent threat of an influenza A epidemic, the knowledge of dynamical and statistical properties of human travel is of fundamental importance. Despite its crucial role, a quantitative assessment of these properties on geographical scales remains elusive, and the assumption that humans disperse diffusively still prevails in models. Here we report on a solid and quantitative assessment of human travelling statistics by analysing the circulation of bank notes in the United States. Using a comprehensive data set of over a million individual displacements, we find that dispersal is anomalous in two ways. First, the distribution of travelling distances decays as a power law, indicating that trajectories of bank notes are reminiscent of scale-free random walks known as Lévy flights. Second, the probability of remaining in a small, spatially confined region for a time T is dominated by algebraically long tails that attenuate the superdiffusive spread. We show that human travelling behaviour can be described mathematically on many spatiotemporal scales by a two-parameter continuous-time random walk model to a surprising accuracy, and conclude that human travel on geographical scales is an ambivalent and effectively superdiffusive process.

  10. Illness in Returned Travellers

    PubMed Central

    Lawee, D.; Scappatura, P.; Gutman, E.

    1989-01-01

    Intercontinental travel is more common now than it has ever been before, and so are travel-related diseases. A thorough history and physical examination provide many clues to possible pathogens, particularly when combined with knowledge of the geographic distribution of specific diseases. Prompt diagnosis and proper treatment are imperative. PMID:21249095

  11. Effect of airline travel on performance: a review of the literature.

    PubMed

    Leatherwood, Whitney E; Dragoo, Jason L

    2013-06-01

    The need for athletes to travel long distances has spurred investigation into the effect of air travel across multiple time zones on athletic performance. Rapid eastward or westward travel may negatively affect the body in many ways; therefore, strategies should be employed to minimise these effects which may hamper athletic performance. In this review, the fundamentals of circadian rhythm disruption are examined along with additional effects of airline travel including jet lag, sleep deprivation, travel at altitude and nutritional considerations that negatively affect performance. Evidence-based recommendations are provided at the end of the manuscript to minimise the effects of airline travel on performance.

  12. 41 CFR 301-11.21 - Will I be reimbursed for per diem or actual expenses on leave or non-workdays (weekend, legal...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... per diem or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or... or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or other... Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL...

  13. 41 CFR 301-11.21 - Will I be reimbursed for per diem or actual expenses on leave or non-workdays (weekend, legal...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... per diem or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or... or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or other... Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL...

  14. 41 CFR 301-11.21 - Will I be reimbursed for per diem or actual expenses on leave or non-workdays (weekend, legal...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... per diem or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or... or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or other... Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL...

  15. 41 CFR 301-11.21 - Will I be reimbursed for per diem or actual expenses on leave or non-workdays (weekend, legal...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... per diem or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or... or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or other... Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL...

  16. 41 CFR 301-11.21 - Will I be reimbursed for per diem or actual expenses on leave or non-workdays (weekend, legal...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... per diem or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or... or actual expenses on leave or non-workdays (weekend, legal Federal Government holiday, or other... Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL...

  17. Air travel and pneumothorax.

    PubMed

    Hu, Xiaowen; Cowl, Clayton T; Baqir, Misbah; Ryu, Jay H

    2014-04-01

    The number of medical emergencies onboard aircraft is increasing as commercial air traffic increases and the general population ages, becomes more mobile, and includes individuals with serious medical conditions. Travelers with respiratory diseases are at particular risk for in-flight events because exposure to lower atmospheric pressure in a pressurized cabin at cruising altitude may result in not only hypoxemia but also pneumothorax due to gas expansion within enclosed pulmonary parenchymal spaces based on Boyle's law. Risks of pneumothorax during air travel pertain particularly to those patients with cystic lung diseases, recent pneumothorax or thoracic surgery, and chronic pneumothorax. Currently available guidelines are admittedly based on sparse data and include recommendations to delay air travel for 1 to 3 weeks after thoracic surgery or resolution of the pneumothorax. One of these guidelines declares existing pneumothorax to be an absolute contraindication to air travel although there are reports of uneventful air travel for those with chronic stable pneumothorax. In this article, we review the available data regarding pneumothorax and air travel that consist mostly of case reports and retrospective surveys. There is clearly a need for additional data that will inform decisions regarding air travel for patients at risk for pneumothorax, including those with recent thoracic surgery and transthoracic needle biopsy. PMID:24687705

  18. [Vaccinations for international travelers].

    PubMed

    Berens-Riha, N; Alberer, M; Löscher, T

    2014-03-01

    Vaccinations are a prominent part of health preparations before international travel. They can avoid or significantly reduce the risk of numerous infectious diseases. Until recently, vaccination against yellow fever was the only obligatory vaccination. However, according to updated international health regulations, other vaccinations and prophylactic measures may be required at entry from certain countries. For all routine vaccinations as recommended in Germany, necessary revaccination and catch-up of missed vaccinations should be administered before travel. At most destinations the risk of infection is higher than in Germany. Hepatitis A vaccine is generally recommended for travelers to areas of increased risk, polio vaccine for all destinations where eradication is not yet confirmed (Asia and Africa). The indications for other travel vaccines must take into consideration travel destination and itinerary, type and duration of travel, individual risk of exposure as well as the epidemiology of the disease to be prevented. Several vaccines of potential interest for travel medicine, e.g., new vaccines against malaria and dengue fever, are under development.

  19. Air travel and pneumothorax.

    PubMed

    Hu, Xiaowen; Cowl, Clayton T; Baqir, Misbah; Ryu, Jay H

    2014-04-01

    The number of medical emergencies onboard aircraft is increasing as commercial air traffic increases and the general population ages, becomes more mobile, and includes individuals with serious medical conditions. Travelers with respiratory diseases are at particular risk for in-flight events because exposure to lower atmospheric pressure in a pressurized cabin at cruising altitude may result in not only hypoxemia but also pneumothorax due to gas expansion within enclosed pulmonary parenchymal spaces based on Boyle's law. Risks of pneumothorax during air travel pertain particularly to those patients with cystic lung diseases, recent pneumothorax or thoracic surgery, and chronic pneumothorax. Currently available guidelines are admittedly based on sparse data and include recommendations to delay air travel for 1 to 3 weeks after thoracic surgery or resolution of the pneumothorax. One of these guidelines declares existing pneumothorax to be an absolute contraindication to air travel although there are reports of uneventful air travel for those with chronic stable pneumothorax. In this article, we review the available data regarding pneumothorax and air travel that consist mostly of case reports and retrospective surveys. There is clearly a need for additional data that will inform decisions regarding air travel for patients at risk for pneumothorax, including those with recent thoracic surgery and transthoracic needle biopsy.

  20. Travel fosters tool use in wild chimpanzees

    PubMed Central

    Gruber, Thibaud; Zuberbühler, Klaus; Neumann, Christof

    2016-01-01

    Ecological variation influences the appearance and maintenance of tool use in animals, either due to necessity or opportunity, but little is known about the relative importance of these two factors. Here, we combined long-term behavioural data on feeding and travelling with six years of field experiments in a wild chimpanzee community. In the experiments, subjects engaged with natural logs, which contained energetically valuable honey that was only accessible through tool use. Engagement with the experiment was highest after periods of low fruit availability involving more travel between food patches, while instances of actual tool-using were significantly influenced by prior travel effort only. Additionally, combining data from the main chimpanzee study communities across Africa supported this result, insofar as groups with larger travel efforts had larger tool repertoires. Travel thus appears to foster tool use in wild chimpanzees and may also have been a driving force in early hominin technological evolution. DOI: http://dx.doi.org/10.7554/eLife.16371.001 PMID:27431611

  1. [Travel destinations South America].

    PubMed

    Neumayr, Andreas

    2013-06-01

    The number of tourists visiting South America comprises only a small fraction of the worldwide stream of international travellers (approx. 980 Mio. in 2011). Nevertheless, their number has markedly increased in the last years (2000: 15.3 Mio.; 2005: 18.3 Mio.; 2010: 23.6 Mio.; 2011: 26.1 Mio.) and in 2011, South America was ranked top in the list of worldwide travel destinations with the highest increase in annual international tourist arrivals (10.4 %)[1]. This article aims at providing a practice-oriented overview on vaccinations, malaria prophylaxis, and other relevant health risks to be considered when counselling travellers visiting South America.

  2. 41 CFR 301-11.3 - Must my agency pay an allowance (either a per diem allowance or actual expense)?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... per diem allowance or actual expense)? Yes, unless: (a) You perform travel to a training event under the Government Employees Training Act (5 U.S.C. 4101-4118), and you agree not to be paid per...

  3. The travel-time ellipse: An approximate zone of transport

    USGS Publications Warehouse

    Almendinger, J.E.

    1994-01-01

    A zone of transport for a well is defined as the area in the horizontal plane bounded by a contour of equal ground-water travel time to the well. For short distances and ground-water travel times near a well, the potentiometric surface may be simulated analytically as that for a fully penetrating well in a uniform flow field. The zone of transport for this configuration is nearly elliptical. A simple method is derived to calculate a travel-time ellipse that approximates the zone of transport for a well in a uniform flow field. The travel-time ellipse was nearly congruent with the exact solution for the theoretical zone of transport for ground-water travel times of at least 10 years and for aquifer property values appropriate for southeastern Minnesota. For distances and travel times approaching infinity, however, the ellipse becomes slightly wider at its midpoint and narrower near its upgradient boundary than the theoretical zone of transport. The travel-time ellipse also may be used to simulate the plume area surrounding an injection well. However, the travel-time ellipse is an approximation that does not account for the effect of dispersion in enlarging the true area of an injection plume or zone of transport; hence, caution is advised in the use and interpretation of this simple construction.

  4. [Travel and cultural activities in care homes for the elderly].

    PubMed

    Andriot, Hervé; Roumilhac, Vanessa

    2010-01-01

    Travel and cultural activities are still accessible for elderly people, in particular those living in care homes. With some precautions and adequate professional supervision, it is possible to carry out such activities, elderly people's limits being psychological rather than physical. Elderly people can thereby open up to the adventure of travelling whether it is an actual, physical trip or a virtual journey, through cultural activities. A report on the Residence Orpea des Noues care home's experience of such initiatives.

  5. Neural Network Solves "Traveling-Salesman" Problem

    NASA Technical Reports Server (NTRS)

    Thakoor, Anilkumar P.; Moopenn, Alexander W.

    1990-01-01

    Experimental electronic neural network solves "traveling-salesman" problem. Plans round trip of minimum distance among N cities, visiting every city once and only once (without backtracking). This problem is paradigm of many problems of global optimization (e.g., routing or allocation of resources) occuring in industry, business, and government. Applied to large number of cities (or resources), circuits of this kind expected to solve problem faster and more cheaply.

  6. Interactive Distance Learning Technology and Connectedness

    ERIC Educational Resources Information Center

    Devlin, Brian; Feraud, Peter; Anderson, Alan

    2008-01-01

    This three-part paper discusses how the contemporary use of computers in distance education is helping to connect students from our rural communities, whether they are located at pastoral stations, remote community schools or are on the road, travelling with parents or carers. The paper is in a sense organised like a sandwich, with technical…

  7. Linguistic Theory and Actual Language.

    ERIC Educational Resources Information Center

    Segerdahl, Par

    1995-01-01

    Examines Noam Chomsky's (1957) discussion of "grammaticalness" and the role of linguistics in the "correct" way of speaking and writing. It is argued that the concern of linguistics with the tools of grammar has resulted in confusion, with the tools becoming mixed up with the actual language, thereby becoming the central element in a metaphysical…

  8. El Observatorio Gemini - Status actual

    NASA Astrophysics Data System (ADS)

    Levato, H.

    Se hace una breve descripción de la situación actual del Observatorio Gemini y de las últimas decisiones del Board para incrementar la eficiencia operativa. Se hace también una breve referencia al uso argentino del observatorio.

  9. [The elderly traveler].

    PubMed

    Brousse, G

    1997-01-01

    An elderly traveler in good health is the same as any other traveler. However before departure elderly subjects should make sure that the proposed schedule of activities is compatible with their physical abilities. Medical counseling should be sought to determine that there are no conflicting health problems or physical impediments. Destination, itinerary, and transportation should selected accordingly. Immunization records should be checked and the main vaccination requirements for elderly subjects should be updated. To avoid running short of any prescribed mediation, an adequate supply for the whole trip must be packed. If air travel is planned, advice should be given on avoiding dehydration and thromboembolism. During his stay at the destination and especially in tropical areas, the subject should get adequate rest and guard against dehydration by drinking sufficiently, protecting against heat exposure, and controlling diarrhea promptly. Using these precautions, elderly subjects can travel as safely as possible.

  10. Travelers' Health: Rubella

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  11. Travelers' Health: Hepatitis C

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... American Association for Study of Liver Diseases (AASLD), Infectious Diseases Society of America (IDSA). Recommendations for testing, managing, ...

  12. Travelers' Health: Hepatitis E

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  13. Travelers' Health: Cryptosporidiosis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  14. Travelers' Health: Leishmaniasis, Cutaneous

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  15. Travelers' Health: Japanese Encephalitis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  16. Travelers' Health: Tickborne Encephalitis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  17. Travelers' Health: Diphtheria

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  18. Travelers' Health: Mumps

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  19. Travelers' Health: Giardiasis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Gabriel PS, Alonso M, et al. Prevalence of infectious diseases among internationally adopted children. Pediatrics. 2001 Sep 3; ...

  20. Travelers' Health: Varicella (Chickenpox)

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Red Book: 2012 Report of the Committee on Infectious Diseases. 29th ed. Elk Grove Village, IL: American Academy ...

  1. Travelers' Health: Hepatitis B

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  2. Travelers' Health: Pertussis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Red Book: 2012 Report of the Committee on Infectious Diseases. 29th ed. Elk Grove Village, IL: American Academy ...

  3. Travelers' Health: Coccidioidomycosis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  4. Travelers' Health: Meningococcal Disease

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Red Book: 2012 Report of the Committee on Infectious Diseases. 29th ed. Elk Grove Village, IL: American Academy ...

  5. Travelers' Health: Scabies

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Red Book: 2012 Report of the Committee on Infectious Diseases. 29th ed. Elk Grove Village, IL: American Academy ...

  6. Travelers' Health: Yellow Fever

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  7. Space Traveler Project.

    ERIC Educational Resources Information Center

    Instructor, 1981

    1981-01-01

    Describes the winners of the Space Traveler Project, a contest jointly sponsored by Rockwell International, NASA, and this magazine to identify worthwhile elementary science programs relating to the Space Shuttle. (SJL)

  8. Traveling-wave photodetector

    DOEpatents

    Hietala, Vincent M.; Vawter, Gregory A.

    1993-01-01

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

  9. Traveling-wave photodetector

    SciTech Connect

    Hietala, V.M.; Vawter, G.A.

    1992-12-31

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

  10. Pregnancy and travel

    MedlinePlus

    ... a day. Always wear your seatbelt. Place the lap belt under your belly and across your hips so ... breasts and across your shoulder. Always wear the lap shoulder seat belt strap when traveling while pregnant. If you have ...

  11. [Diabetes and travel].

    PubMed

    Bauduceau, B; Mayaudon, H; Ducorps, M; Belmejdoub, G; Thiolet, C; Pellan, M; Cosson, E

    1997-01-01

    With the continuing expansion in international air travel, increasing numbers of diabetic patients consult physicians for advice before going abroad. Careful planning is required taking into account climatic and medical conditions at the destination. Diabetic travelers should pack an appropriate treatment kit and contract special insurance coverage for medical evacuation. Precautions are necessary to limit the effects of motion sickness and time differences on diabetes control and especially the risk of hypoglycemia. Special attention is needed to avoid digestive problems and prevent foot injuries which can lead to serious complications in diabetic patients. Diabetic patients cannot forget their health problem during vacation and must be especially cautious when traveling. However with proper training, the risks of foreign travel can be reduced to acceptable levels.

  12. Traveling Space Museum

    NASA Video Gallery

    In an effort to inspire and motivate the next generation of space explorers, NASA’s Ames Research Center teamed up with the Traveling Space Museum to teach students the way astronauts are taughtâ...

  13. Travel Inside the Ear

    MedlinePlus

    ... Menu Home Health Info Hearing, Ear Infections, and Deafness Balance Taste and Smell Voice, Speech, and Language ... here Home » Health Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves ...

  14. Traveling Wave Demonstration.

    ERIC Educational Resources Information Center

    Kluger-Bell, Barry

    1995-01-01

    Describes a traveling-wave demonstration that uses inexpensive materials (crepe-paper streamers) and is simple to assemble and perform. Explains how the properties of light waves are illustrated using the demonstration apparatus. (LZ)

  15. Traveling-wave photodetector

    DOEpatents

    Hietala, V.M.; Vawter, G.A.

    1993-12-14

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.

  16. Travel during Pregnancy

    MedlinePlus

    ... of pregnancy. If you are planning an international flight, the cutoff point for traveling with international airlines ... up and stretch your legs during a long flight. Avoid gas-producing foods and carbonated drinks before ...

  17. Advice to Travelers

    PubMed Central

    Barrett-Connor, Elizabeth

    1975-01-01

    Travelers, particularly those whose tastes or occupations lead to deviation from the usual tourist routes, are at a small but significant risk of acquiring certain diseases they would be unlikely to encounter had they remained in the continental United States. Many of these infections can be rendered unlikely even for the most adventuresome traveler through the appropriate use of immunization and chemoprophylaxis. Other infections are currently unpreventable and the physician's responsibility lies in their premorbid detection. PMID:1154779

  18. On the Treatment of Airline Travelers in Mathematical Models

    PubMed Central

    Johansson, Michael A.; Arana-Vizcarrondo, Neysarí; Biggerstaff, Brad J.; Staples, J. Erin; Gallagher, Nancy; Marano, Nina

    2011-01-01

    The global spread of infectious diseases is facilitated by the ability of infected humans to travel thousands of miles in short time spans, rapidly transporting pathogens to distant locations. Mathematical models of the actual and potential spread of specific pathogens can assist public health planning in the case of such an event. Models should generally be parsimonious, but must consider all potentially important components of the system to the greatest extent possible. We demonstrate and discuss important assumptions relative to the parameterization and structural treatment of airline travel in mathematical models. Among other findings, we show that the most common structural treatment of travelers leads to underestimation of the speed of spread and that connecting travel is critical to a realistic spread pattern. Models involving travelers can be improved significantly by relatively simple structural changes but also may require further attention to details of parameterization. PMID:21799782

  19. Distance and Cable Length Measurement System

    PubMed Central

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  20. The Traveling Microbiome.

    PubMed

    Riddle, Mark S; Connor, Bradley A

    2016-09-01

    Given the recent interest in the human gut microbiome in health and disease, we have undertaken a review of the role of the gut microbiome as it relates to travel. Considering the microbiome as the interface with the external world of the traveler, not only from the perspective of protection from enteric infection by colonization resistance but also the possibility that a traveler's unique microbiome may place him or her at lesser or greater risk for enteric infection. We review available data on travel, travelers' diarrhea, and the use of antibiotics as it relates to changes in the microbiome and the acquisition of multi-drug-resistant bacteria and explore the interplay of these factors in the development of dysbiosis and the post-infectious sequelae of TD, specifically PI-IBS. In addition, we explore whether dietary changes in travel affect the gut microbiome in a way which modulates gastrointestinal function and susceptibility to infection and discuss whether pre- or probiotics have any meaningful role in prevention or treatment of TD. Finally, a discussion of important research gaps and opportunities in this area is identified. PMID:27447891

  1. 75 FR 43395 - Campaign Travel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ... of 2007. See Final Rules on Campaign Travel, 74 FR 63951 (Dec. 7, 2009) (the ``Travel Rules... 11 CFR 9004.7 at a later date. Travel Rules, 74 FR at 63951. Through this Notice, the Commission... of the Honest Leadership and Open Government Act governing campaign travel on noncommercial...

  2. [Travellers to South America].

    PubMed

    Lloveras, Susana Cristina

    2011-12-01

    The geography, tourist attractions and the multiple sites of historical and cultural interest make South America as an important destination chosen by travelers. The continent has a wide climatic variation from north to south, making exposure to risk different between the tropics and the temperate or cold regions. In the countries of tropical South America, the greatest risk is associated with the possibility of acquiring vector-borne diseases, like yellow fever, dengue, malaria and leishmaniasis. The risk of acquiring traveler's diarrhea and food-borne illness is similar across the continent, with some variations according to country and to visit urban or rural areas. Rabies, pertussis and diphtheria have appeared as epidemics in several countries and other diseases such as rickettsiosis, hantavirosis and viral encephalitis have expanded their distribution. The geographic and epidemiological diversity of South America, promotes a challenge for travel medicine specialists because during the pre-travel advice they have to take in account the kind of trip, traveller's medical history, exposure to risk and the dynamics of endemic emerging and reemerging diseases in the region.

  3. [Investigating fever after travel].

    PubMed

    D'Acremont, Valérie; Jaquérioz, Frédérique; Genton, Blaise

    2003-02-01

    Two questions are crucial in the evaluation of fever in returning travellers, i.e. "Where have you been?" and "When did you go and when did you return from your trip?". Prior to establishing practice guidelines for fever in returning travellers and migrants, we did a systematic review of the geographical distribution of all infectious diseases in the tropical and subtropical countries. In the present paper, results are summarized by disease per continent. We also reviewed the extreme ranges for the incubation of the same diseases. Results are expressed graphically. Detailed information on space and time should help the practitioner to do an appropriate differential diagnosis, in particular to exclude diseases that are absent in the country visited or diseases with an incubation period that is incompatible with the travel history and symptoms occurrence dates.

  4. [Pregnancy and traveling].

    PubMed

    Walentiny, C

    2009-03-01

    The second trimester is the safest time for travelling, because the pregnant woman feels generally most at ease and the risk of spontaneous abortion and pre-term labour is very low. Possible risks must be discussed with the obstetrician before travelling. If the pregnancy is uncomplicated most airlines allow flying up to the 36th (domestic flights) and 35th (international flights) week of gestation. Unless the fetal oxygen supply is already impaired at ground level due to an underlying disease, flying does not pose a risk of fetal hypoxia. Radiation exposure during a long distant flight is low compared to the average annual exposure dosage, but the risk of thrombosis is increased. Altitudes up to 2,500 m pose no problem. Sufficient time to acclimatize must be taken when travelling to high altitudes and exercise kept to a minimum. Scuba diving is contraindicated. Since only a few drugs are completely safe during pregnancy a thorough risk/benefit evaluation is mandatory. Treatment of infections can be considerably complicated, but any necessary treatment should not be withheld because of the fear of potential fetal injury. Good knowledge of local medical resources is essential before travelling. Several personal protective measures minimize the risk of infection: food and water precautions, protection from insect bites and avoidance of crowds, unsafe sex and, if need be, freshwater. Many vaccinations are recommended for travellers. However, live vaccines are contraindicated in pregnant women because of theoretical considerations. Exceptionally a yellow fever vaccination may be given after the first trimester. Killed, inactivated or polysaccharide vaccines can be given after the first trimester after a thorough risk/benefit evaluation. Because of the potentially devastating effect of malaria to the mother and the child, travelling to endemic malaria regions should be avoided. If the risk of infection is high chemoprophylaxis with mefloquine is indicated. In low

  5. Virtual Proctoring in Distance Education: An Open-Source Solution

    ERIC Educational Resources Information Center

    Rose, Chris

    2009-01-01

    Students will cheat during exams, that is nothing new, but now that the Higher Education Act requires the proctoring of exams, distance education institutions now find that both they and their students have a major problem. Exams have to be proctored, but requiring distance education students to search out a reliable proctor and travel to a…

  6. Culture shock and travelers.

    PubMed

    Stewart, L; Leggat, P A

    1998-06-01

    As travel has become easier and more affordable, the number of people traveling has risen sharply. People travel for many and varied reasons, from the business person on an overseas assignment to backpackers seeking new and exotic destinations. Others may take up residence in different regions, states or countries for family, business or political reasons. Other people are fleeing religious or political persecution. Wherever they go and for whatever reason they go, people take their culture with them. Culture, like language, is acquired innately in early childhood and is then reinforced through formal and complex informal social education into adulthood. Culture provides a framework for interpersonal and social interactions. Therefore, the contact with a new culture is often not the exciting or pleasurable experience anticipated. When immersed in a different culture, people no longer know how to act when faced with disparate value systems. Contact with the unfamiliar culture can lead to anxiety, stress, mental illness and, in extreme cases, physical illness and suicide. "Culture shock" is a term coined by the anthropologist Oberg. It is the shock of the new. It implies that the experience of the new culture is an unpleasant surprise or shock, partly because it is unexpected and partly because it can lead to a negative evaluation of one's own culture. It is also known as cross-cultural adjustment, being that period of anxiety and confusion experienced when entering a new culture. It affects people intellectually, emotionally, behaviorally and physically and is characterized by symptoms of psychological distress. Culture shock affects both adults and children. In travelers or workers who have prolonged sojourns in foreign countries, culture shock may occur not only as they enter the new culture, but also may occur on their return to their original culture. Children may also experience readjustment problems after returning from leading sheltered lives in expatriate

  7. Malaria prevention in travelers.

    PubMed

    Genton, Blaise; D'Acremont, Valérie

    2012-09-01

    A common approach to malaria prevention is to follow the "A, B, C, D" rule: Awareness of risk, Bite avoidance, Compliance with chemoprophylaxis, and prompt Diagnosis in case of fever. The risk of acquiring malaria depends on the length and intensity of exposure; the risk of developing severe disease is primarily determined by the health status of the traveler. These parameters need to be assessed before recommending chemoprophylaxis and/or stand-by emergency treatment. This review discusses the different strategies and drug options available for the prevention of malaria during and post travel.

  8. Intergalactic Travel Bureau

    NASA Astrophysics Data System (ADS)

    Koski, Olivia; Rosin, Mark; Guerilla Science Team

    2014-03-01

    The Intergalactic Travel Bureau is an interactive theater outreach experience that engages the public in the incredible possibilities of space tourism. The Bureau is staffed by professional actors, who play the role of space travel agents, and professional astrophysicists, who play the role of resident scientists. Members of the public of all ages were invited to visit with bureau staff to plan the vacation of their dreams-to space. We describe the project's successful nine day run in New York in August 2013. Funded by the American Physical Society Public Outreach and Informing the Public Grants.

  9. Who Am I as a Distance Tutor? An Investigation of Distance Tutors' Professional Identity in China

    ERIC Educational Resources Information Center

    Xiao, Junhong

    2016-01-01

    Much research has been conducted in the area of teacher professional identity in the past decades. Nonetheless, very little attention has been paid to the professional identity of tutors in distance education. Using interviews, this study set out to investigate distance tutors' claimed and assigned professional identities, their actual, ought and…

  10. How People Actually Use Thermostats

    SciTech Connect

    Meier, Alan; Aragon, Cecilia; Hurwitz, Becky; Mujumdar, Dhawal; Peffer, Therese; Perry, Daniel; Pritoni, Marco

    2010-08-15

    Residential thermostats have been a key element in controlling heating and cooling systems for over sixty years. However, today's modern programmable thermostats (PTs) are complicated and difficult for users to understand, leading to errors in operation and wasted energy. Four separate tests of usability were conducted in preparation for a larger study. These tests included personal interviews, an on-line survey, photographing actual thermostat settings, and measurements of ability to accomplish four tasks related to effective use of a PT. The interviews revealed that many occupants used the PT as an on-off switch and most demonstrated little knowledge of how to operate it. The on-line survey found that 89% of the respondents rarely or never used the PT to set a weekday or weekend program. The photographic survey (in low income homes) found that only 30% of the PTs were actually programmed. In the usability test, we found that we could quantify the difference in usability of two PTs as measured in time to accomplish tasks. Users accomplished the tasks in consistently shorter times with the touchscreen unit than with buttons. None of these studies are representative of the entire population of users but, together, they illustrate the importance of improving user interfaces in PTs.

  11. Transferring 2001 National Household Travel Survey

    SciTech Connect

    Hu, Patricia S; Reuscher, Tim; Schmoyer, Richard L; Chin, Shih-Miao

    2007-05-01

    Policy makers rely on transportation statistics, including data on personal travel behavior, to formulate strategic transportation policies, and to improve the safety and efficiency of the U.S. transportation system. Data on personal travel trends are needed to examine the reliability, efficiency, capacity, and flexibility of the Nation's transportation system to meet current demands and to accommodate future demand. These data are also needed to assess the feasibility and efficiency of alternative congestion-mitigating technologies (e.g., high-speed rail, magnetically levitated trains, and intelligent vehicle and highway systems); to evaluate the merits of alternative transportation investment programs; and to assess the energy-use and air-quality impacts of various policies. To address these data needs, the U.S. Department of Transportation (USDOT) initiated an effort in 1969 to collect detailed data on personal travel. The 1969 survey was the first Nationwide Personal Transportation Survey (NPTS). The survey was conducted again in 1977, 1983, 1990, 1995, and 2001. Data on daily travel were collected in 1969, 1977, 1983, 1990 and 1995. In 2001, the survey was renamed the National Household Travel Survey (NHTS) and it collected both daily and long-distance trips. The 2001 survey was sponsored by three USDOT agencies: Federal Highway Administration (FHWA), Bureau of Transportation Statistics (BTS), and National Highway Traffic Safety Administration (NHTSA). The primary objective of the survey was to collect trip-based data on the nature and characteristics of personal travel so that the relationships between the characteristics of personal travel and the demographics of the traveler can be established. Commercial and institutional travel were not part of the survey. Due to the survey's design, data in the NHTS survey series were not recommended for estimating travel statistics for categories smaller than the combination of Census division (e.g., New England, Middle

  12. The Role of Perspective in Mental Time Travel.

    PubMed

    Ansuini, Caterina; Cavallo, Andrea; Pia, Lorenzo; Becchio, Cristina

    2016-01-01

    Recent years have seen accumulating evidence for the proposition that people process time by mapping it onto a linear spatial representation and automatically "project" themselves on an imagined mental time line. Here, we ask whether people can adopt the temporal perspective of another person when travelling through time. To elucidate similarities and differences between time travelling from one's own perspective or from the perspective of another person, we asked participants to mentally project themselves or someone else (i.e., a coexperimenter) to different time points. Three basic properties of mental time travel were manipulated: temporal location (i.e., where in time the travel originates: past, present, and future), motion direction (either backwards or forwards), and temporal duration (i.e., the distance to travel: one, three, or five years). We found that time travels originating in the present lasted longer in the self- than in the other-perspective. Moreover, for self-perspective, but not for other-perspective, time was differently scaled depending on where in time the travel originated. In contrast, when considering the direction and the duration of time travelling, no dissimilarities between the self- and the other-perspective emerged. These results suggest that self- and other-projection, despite some differences, share important similarities in structure.

  13. The Role of Perspective in Mental Time Travel

    PubMed Central

    Ansuini, Caterina; Cavallo, Andrea; Pia, Lorenzo; Becchio, Cristina

    2016-01-01

    Recent years have seen accumulating evidence for the proposition that people process time by mapping it onto a linear spatial representation and automatically “project” themselves on an imagined mental time line. Here, we ask whether people can adopt the temporal perspective of another person when travelling through time. To elucidate similarities and differences between time travelling from one's own perspective or from the perspective of another person, we asked participants to mentally project themselves or someone else (i.e., a coexperimenter) to different time points. Three basic properties of mental time travel were manipulated: temporal location (i.e., where in time the travel originates: past, present, and future), motion direction (either backwards or forwards), and temporal duration (i.e., the distance to travel: one, three, or five years). We found that time travels originating in the present lasted longer in the self- than in the other-perspective. Moreover, for self-perspective, but not for other-perspective, time was differently scaled depending on where in time the travel originated. In contrast, when considering the direction and the duration of time travelling, no dissimilarities between the self- and the other-perspective emerged. These results suggest that self- and other-projection, despite some differences, share important similarities in structure. PMID:26881103

  14. Mentors as Fellow Travelers

    ERIC Educational Resources Information Center

    Ambrosino, Roberta

    2009-01-01

    A junior faculty member arrives at an unfamiliar university for a new teaching assignment. She is poised for the adventure, but feels like a traveler at the edge of long, unknown road. She does not know what obstacles or vistas may appear on the road, and wants to avoid major potholes. She takes a nervous look around and finds an experienced…

  15. Risk for Travelers

    MedlinePlus

    ... specified risk materials from animal feed and human food chains as of October 1, 2000; such bans had already been instituted in most member states. To reduce any risk of acquiring vCJD from food, concerned travelers to Europe or other areas with ...

  16. Family travel: an overview.

    PubMed

    Neumann, Karl

    2006-01-01

    Paediatric travel medicine involves the education of parents about the numerous health and safety issues related to traveling with infants and young children--whether overseas or a weekend at a local lake. It includes providing children with vaccines and medications, giving telephone advice to parents while they are traveling, and treating children should they come home ill. Practitioners must be knowledgeable about such varied topics like avoiding diarrhoea, infant safety seats for air travel, altitude sickness, sun exposure, waterfront safety, insect protection, dealing with hot and cold environments, and at what age it is safe to begin scuba diving, to name just a very few. Practitioners must also know when adult recommendations can--and cannot--be adapted for children; that vaccine doses, needle size, and injection site may vary with the size of the child; and the answers to hundreds of everyday questions such as how to administer an essential but bitter tasting medication to an uncooperative child--and what to do when the child refuses to take the medication or vomits it.

  17. Time travel paradox

    NASA Astrophysics Data System (ADS)

    Krasnikov, S.

    2002-03-01

    We define the time travel paradox in physical terms and prove its existence by constructing an explicit example. We argue further that in theories-such as general relativity-where the spacetime geometry is subject to nothing but differential equations and initial data no paradoxes arise.

  18. Traveling in France.

    ERIC Educational Resources Information Center

    Philyaw, Henry; And Others

    This minicourse guide for teachers of French is intended to help motivate and prepare students for travel in France. Activities are outlined in eleven related areas, including (1) planning for the trip, (2) currency, (3) going through customs, (4) tipping, (5) shopping, (6) guided tours, (7) touring on your own, (8) social life and entertainment,…

  19. Malaria: prevention in travellers

    PubMed Central

    2007-01-01

    Introduction Malaria transmission occurs most frequently in environments with humidity over 60% and ambient temperature of 25-30 °C. Risks increase with longer visits and depend on activity. Infection can follow a single mosquito bite. Incubation is usually 10-14 days but can be up to 18 months depending on the strain of parasite. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug preventive interventions in adult travellers? What are the effects of drug prophylaxis in adult travellers? What are the effects of antimalaria vaccines in travellers? What are the effects of antimalaria interventions in child travellers, pregnant travellers, and in airline pilots? We searched: Medline, Embase, The Cochrane Library and other important databases up to February 2006 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 69 systematic reviews, RCTs, or observational studies that met our inclusion criteria. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: acoustic buzzers, aerosol insecticides, amodiaquine, air conditioning and electric fans, atovaquone-proguanil, biological control measures, chloroquine (alone or with proguanil), diethyltoluamide (DEET), doxycycline, full-length and light-coloured clothing, insecticide-treated clothing/nets, mefloquine, mosquito coils and vaporising mats, primaquine, pyrimethamine-dapsone, pyrimethamine-sulfadoxine, smoke, topical (skin-applied) insect repellents, and vaccines. PMID:19450348

  20. Malaria: prevention in travellers

    PubMed Central

    2010-01-01

    Introduction Malaria transmission occurs most frequently in environments with humidity greater than 60% and ambient temperature of 25 °C to 30 °C. Risks increase with longer visits and depend on activity. Infection can follow a single mosquito bite. Incubation is usually 10 to 14 days but can be up to 18 months depending on the strain of parasite. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug preventive interventions in non-pregnant adult travellers? What are the effects of drug prophylaxis in non-pregnant adult travellers? What are the effects of antimalaria vaccines in adult and child travellers? What are the effects of antimalaria interventions in child travellers, pregnant travellers, and in airline pilots? We searched: Medline, Embase, The Cochrane Library, and other important databases up to November 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 79 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: aerosol insecticides, amodiaquine, air conditioning and electric fans, atovaquone–proguanil, biological control measures, chloroquine (alone or with proguanil), diethyltoluamide (DEET), dietary supplementation, doxycycline, electronic mosquito repellents, full-length and light-coloured clothing, insecticide-treated clothing/nets, mefloquine, mosquito coils and vapourising mats, primaquine, pyrimethamine–dapsone, pyrimethamine–sulfadoxine, smoke

  1. Defining Distance Learning and Distance Education.

    ERIC Educational Resources Information Center

    King, Frederick B.; Young, Michael F.; Drivere-Richmond, Kelly; Schrader, P. G.

    2001-01-01

    This paper offers precise definitions of distance learning and distance education, and their interrelationship. First, a single definition of learning is proposed, and then the concept of learning is broken down into three subcategories: instruction, exploration, and serendipity. Each is defined and the concepts of distance learning and distance…

  2. Evaluating School Travel Initiatives and Promoting "Healthy Travel" through PSHCE

    ERIC Educational Resources Information Center

    Baslington, Hazel

    2010-01-01

    The number of primary school children travelling to school by car in the UK has almost doubled from 22% to 43% in 20 years. A governmental policy response is school travel plans (STPs). This paper reports the findings of an empirical evaluation designed to measure the effectiveness of the travel initiative at three schools. Quantitative and…

  3. Global aerial flyways allow efficient travelling.

    PubMed

    Kranstauber, B; Weinzierl, R; Wikelski, M; Safi, K

    2015-12-01

    Birds migrate over vast distances at substantial costs. The highly dynamic nature of the air makes the selection of the best travel route difficult. We investigated to what extent migratory birds may optimise migratory route choice with respect to wind, and if route choice can be subject to natural selection. Following the optimal route, calculated using 21 years of empirical global wind data, reduced median travel time by 26.5% compared to the spatially shortest route. When we used a time-dependent survival model to quantify the adaptive benefit of choosing a fixed wind-optimised route, 84.8% of pairs of locations yielded a route with a higher survival than the shortest route. This suggests that birds, even if incapable of predicting wind individually, could adjust their migratory routes at a population level. As a consequence, this may result in the emergence of low-cost flyways representing a global network of aerial migratory pathways.

  4. Unsteady planar diffusion flames: Ignition, travel, burnout

    NASA Technical Reports Server (NTRS)

    Fendell, F.; Wu, F.

    1995-01-01

    In microgravity, a thin planar diffusion flame is created and thenceforth travels so that the flame is situated at all times at an interface at which the hydrogen and oxygen meet in stoichiometric proportion. If the initial amount of hydrogen is deficient relative to the initial amount of oxygen, then the planar flame will travel further and further into the half volume initially containing hydrogen, until the hydrogen is (virtually) fully depleted. Of course, when the amount of residual hydrogen becomes small, the diffusion flame is neither vigorous nor thin; in practice, the flame is extinguished before the hydrogen is fully depleted, owing to the finite rate of the actual chemical-kinetic mechanism. The rate of travel of the hydrogen-air diffusion flame is much slower than the rate of laminar flame propagation through a hydrogen-air mixture. This slow travel facilitates diagnostic detection of the flame position as a function of time, but the slow travel also means that the time to burnout (extinction) probably far exceeds the testing time (typically, a few seconds) available in earth-sited facilities for microgravity-environment experiments. We undertake an analysis to predict (1) the position and temperature of the diffusion flame as a function of time, (2) the time at which extinction of the diffusion flame occurs, and (3) the thickness of quench layers formed on side walls (i.e., on lateral boundaries, with normal vectors parallel to the diffusion-flame plane), and whether, prior to extinction, water vapor formed by burning will condense on these cold walls.

  5. 41 CFR 301-11.300 - When is actual expense reimbursement warranted?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false When is actual expense reimbursement warranted? 301-11.300 Section 301-11.300 Public Contracts and Property Management Federal Travel... meals are procured at a prearranged place such as a hotel where a meeting, conference or...

  6. Travelling with a Tachograph.

    ERIC Educational Resources Information Center

    Bradshaw, John R.

    1990-01-01

    Presented are activities which use data from an instrument which combines speedometer, odometer, and clock readings on a circular graph. Applications of linear graphs using actual and simulated tachographs are discussed. Examples of student work are given. (CW)

  7. International business travel: impact on families and travellers

    PubMed Central

    Espino, C; Sundstrom, S; Frick, H; Jacobs, M; Peters, M

    2002-01-01

    Objectives: Spouses and staff of the World Bank Group (WBG) were questioned about the impact of international business travel on families and travellers. Dependent variables were self reported stress, concern about the health of the traveller, and negative impact on the family. We hypothesised that several travel factors (independent variables) would be associated with these impacts. These travel factors had to do with the frequency, duration, and predictability of travel and its interference with family activities. Methods: Survey forms were developed and distributed to all spouses of travelling staff as well as a small sample of operational staff. Kendall's tau b correlation coefficients of response frequencies were computed with the data from scaled items. Written responses to open ended questions were categorised. Results: Response rates for spouses and staff were 24% and 36%, respectively. Half the spouse sample (n=533) and almost 75% of the staff sample (n=102) reported high or very high stress due to business travel. Self reported spouse stress was associated with six out of eight travel factors. Female spouses, those with children, and younger spouses reported greater stress. Self reported staff stress was significantly associated with four out of nine travel factors. Further insight into how business travel affects families and staff (including children's behavioural changes) and how families cope was gained through responses to written questions. Conclusions: The findings support the notion that lengthy and frequent travel and frequent changes in travel dates which affect family plans, all characteristic of WBG missions, negatively affects many spouses and children (particularly young children) and that the strain on families contributes significantly to the stress staff feel about their travel. Policies or management practices that take into consideration family activities and give staff greater leeway in controlling and refusing travel may help relieve

  8. Travel and Adventure Medicine Resources.

    PubMed

    Sanford, Christopher A; Pottinger, Paul S

    2016-03-01

    Given the ever-changing nature of travel medicine, practitioners who provide pretravel and posttravel care are obligatorily students for the duration of their professional careers. A large variety of resources are available for medical practitioners. Providers should join at least one travel or tropical medicine professional association, attend its annual meeting, and read its journal. The largest general travel medicine association is the International Society of Travel Medicine. PMID:26900122

  9. Travel and Adventure Medicine Resources.

    PubMed

    Sanford, Christopher A; Pottinger, Paul S

    2016-03-01

    Given the ever-changing nature of travel medicine, practitioners who provide pretravel and posttravel care are obligatorily students for the duration of their professional careers. A large variety of resources are available for medical practitioners. Providers should join at least one travel or tropical medicine professional association, attend its annual meeting, and read its journal. The largest general travel medicine association is the International Society of Travel Medicine.

  10. Including Gypsy Travellers in Education.

    ERIC Educational Resources Information Center

    Lloyd, Gwynned; Stead, Joan

    2002-01-01

    Examined the educational exclusion and inclusion of Gypsy Traveller students, exploring how some Scottish schools responded to Traveller student culture and how this led to exclusion. Interviews with school staff, Traveller students, and parents indicated that continuing prejudice and harassment promoted inappropriate school placement and…

  11. Travelers In The Night

    NASA Astrophysics Data System (ADS)

    Grauer, Albert D.

    2014-11-01

    Travelers In The Night is an engaging and informative series of two minute radio programs about asteroids, comets, spacecraft, and other objects in space. The pieces are evergreen in that they are current but not dated. They are published on the Public Radio Exchange and carried by a number of radio stations. For teachers, students, and kids of all ages, the script for each piece and the start of a path for further inquiry can be found on the website travelersinthenight.org . The Travelers InThe Night Pieces are written and produced by an observing member of the Catalina Sky Survey Team at the University of Arizona. DPS members are encouraged to submit program ideas which can be developed to feature their research efforts.

  12. [Travel and renal insufficiency].

    PubMed

    Lavelle, O; Berland, Y

    1997-01-01

    Traveling can be dangerous for subjects with kidney insufficiency. Water loss or septic episodes can further increase renal dysfunction. Poor diet can lead to hyperkaliemia. Immunosuppression not only enhances the risk of infection but also complicates administration of live vaccines. Some antimalarial drugs are contraindicated (e.g. mefloquine) and others must be used with precaution. Prior to departure persons requiring hemodialysis should book sessions at centers listed in specialized guidebooks. In addition to infection, risks for hemodialysis patients include thrombosis of the arteriovenous fistula in case of dehydration or hypotension. In subjects with transplanted kidney, the risk of rejection can be enhanced either by poor compliance with immunodepressor treatment or by vaccination-induced antigenic stimulation. Pre-travel evaluation is necessary to determine metabolic, nutritional, and immune status. Subjects with kidney insufficiency and transplanted kidneys should be informed of the dangers and appropriate action in case of trouble.

  13. Covariates affecting spatial variability in bison travel behavior in Yellowstone National Park.

    PubMed

    Bruggeman, Jason E; Garrott, Robert A; White, P J; Watson, Fred G R; Wallen, Rick

    2007-07-01

    Understanding mechanisms influencing the movement paths of animals is essential for comprehending behavior and accurately predicting use of travel corridors. In Yellowstone National Park (USA), the effects of roads and winter road grooming on bison (Bison bison) travel routes and spatial dynamics have been debated for more than a decade. However, no rigorous studies have been conducted on bison spatial movement patterns. We collected 121 380 locations from 14 female bison with GPS collars in central Yellowstone to examine how topography, habitat type, roads, and elevation affected the probability of bison travel year-round. We also conducted daily winter bison road use surveys (2003-2005) to quantify how topography and habitat type influenced spatial variability in the amount of bison road travel. Using model comparison techniques, we found the probability of bison travel and spatial distribution of travel locations were affected by multiple topographic and habitat type attributes including slope, landscape roughness, habitat type, elevation, and distances to streams, foraging areas, forested habitats, and roads. Streams were the most influential natural landscape feature affecting bison travel, and results suggest the bison travel network throughout central Yellowstone is spatially defined largely by the presence of streams that connect foraging areas. Also, the probability of bison travel was higher in regions of variable topography that constrain movements, such as in canyons. Pronounced travel corridors existed both in close association with roads and distant from any roads, and results indicate that roads may facilitate bison travel in certain areas. However, our findings suggest that many road segments used as travel corridors are overlaid upon natural travel pathways because road segments receiving high amounts of bison travel had similar landscape features as natural travel corridors. We suggest that most spatial patterns in bison road travel are a

  14. Aging and space travel

    NASA Technical Reports Server (NTRS)

    Mohler, S. R.

    1982-01-01

    The matter of aging and its relation to space vehicle crewmembers undertaking prolonged space missions is addressed. The capabilities of the older space traveler to recover from bone demineralization and muscle atrophy are discussed. Certain advantages of the older person are noted, for example, a greater tolerance of monotony and repetitious activities. Additional parameters are delineated including the cardiovascular system, the reproductive system, ionizing radiation, performance, and group dynamics.

  15. [Traveling with small children].

    PubMed

    Olivier, C

    1997-01-01

    Traveling with children especially in the tropics requires special planning. Contraindications are rare but care providers should obtain information about medical and transfusional facilities at the destination. Children should receive all vaccinations required for international travel and for specific countries, taking into account age, location, duration of stay, and purpose of trip. A first aid kit should be packed containing a thermometer, bandages, antiseptic agents, a total sunscreen preparation, a mosquito net, sterile compresses, tablets for water disinfection, and indispensable medications (antimalarial agents, antipyretics, oral rehydration solutions, antiemetics, and eye wash). The main indication for chemoprophylaxis is malaria. Chloroquine is recommended for most locations but proguanil may be necessary in areas of resistance. Special attention must be paid to skin care in infants: maintaining cleanliness, avoiding cuts insofar as possible, and treating any wounds. Clothing must be carefully laundered and adequate to prevent overexposure to sunlight and insect bites. Insect bites must also be prevented by applying repellents, using mosquito nets, and wearing insecticide-treated garments. Handwashing by people who prepare meals and by the children before eating is important to prevent food poisoning. Breast feeding is advisable for infants. Thorough cooking of meats, rinsing of fresh produce, drinking of bottled beverages, and sterilization of water are also important food safety measures. These precautions are usually adequate to allow safe travel with children.

  16. Time - A Traveler's Guide

    NASA Astrophysics Data System (ADS)

    Pickover, Clifford A.

    1999-09-01

    "Bucky Fuller thought big," Wired magazine recently noted, "Arthur C. Clarke thinks big, but Cliff Pickover outdoes them both." In his newest book, Cliff Pickover outdoes even himself, probing a mystery that has baffled mystics, philosophers, and scientists throughout history--What is the nature of time?In Time: A Traveler's Guide , Pickover takes readers to the forefront of science as he illuminates the most mysterious phenomenon in the universe--time itself. Is time travel possible? Is time real? Does it flow in one direction only? Does it have a beginning and an end? What is eternity? Pickover's book offers a stimulating blend of Chopin, philosophy, Einstein, and modern physics, spiced with diverting side-trips to such topics as the history of clocks, the nature of free will, and the reason gold glitters. Numerous diagrams ensure readers will have no trouble following along.By the time we finish this book, we understand a wide variety of scientific concepts pertaining to time. And most important, we will understand that time travel is, indeed, possible.

  17. [Travelers, mad, wandering].

    PubMed

    Vaschetto, Emilio

    2014-01-01

    This article explores the notion of "wandering" through the use of some phenomena enrolled at the dawn of modernity such as the Rousseau dromomanie's philosopher and writer, the origin of the first mad traveler (Albert Dadas), epidemics of mad travelers Europe and romantic tourism (with renewed acquires significance in the "beat generation" of the twentieth century). These historical facts are "mounting" as play contemporary manifestations such as loss, disorientation, to lose one's way, and wandering without reducing them only to clinical psychosis. Readings of classic psychiatrists such as Régis, Foville, Sérieux and Capgras, Tissié, go hand in hand with the current readings of the philosopher Ian Hacking and critics of pop culture as S. Reynolds and D. Diederichsen, illustrating how the travel's phenomenon can make different subjective configurations depending on historical times. In conclusion it is noted that not only psychosis exposes the wandering soul of suffering but there are also subject positions (as will be exemplified in a clinical case) and go no further nesting wandering into human existence. PMID:25153978

  18. Family planning for travellers.

    PubMed

    Rustom, A

    1990-11-01

    A public health nurse from London describes the customs of nomadic people in the British Isles, known as "travellers," as they affect provision of family planning services. Most are of British or Irish stock, some migrate and others live in caravan sites all year. Their traditions dictate that men work and women are housewives. Early, often arranged, marriage, early childbearing and large families are the norm. Sex and contraception are not considered appropriate for discussion between the sexes, or in the presence of children. Large families and financial hardship force many women to space pregnancies. Women often have to hide contraceptives from their husbands, difficult in conditions without privacy. Therefore they prefer IUDs, but some use oral contraceptives, although sometimes erratically because most are illiterate. Traveller women are usually unwilling to do self-examination, as needed with IUDs. They often have difficulty attending regular Pap smear clinics. Cervical cancer rates are high. They experience discrimination in clinics, and need extra care about modesty. It is worth while to take time to develop trust in the clinical relationship, to deal with the traveller woman's uneasy among outsiders.

  19. Ion acoustic traveling waves

    NASA Astrophysics Data System (ADS)

    Webb, G. M.; Burrows, R. H.; Ao, X.; Zank, G. P.; Zank

    2014-04-01

    Models for traveling waves in multi-fluid plasmas give essential insight into fully nonlinear wave structures in plasmas, not readily available from either numerical simulations or from weakly nonlinear wave theories. We illustrate these ideas using one of the simplest models of an electron-proton multi-fluid plasma for the case where there is no magnetic field or a constant normal magnetic field present. We show that the traveling waves can be reduced to a single first-order differential equation governing the dynamics. We also show that the equations admit a multi-symplectic Hamiltonian formulation in which both the space and time variables can act as the evolution variable. An integral equation useful for calculating adiabatic, electrostatic solitary wave signatures for multi-fluid plasmas with arbitrary mass ratios is presented. The integral equation arises naturally from a fluid dynamics approach for a two fluid plasma, with a given mass ratio of the two species (e.g. the plasma could be an electron-proton or an electron-positron plasma). Besides its intrinsic interest, the integral equation solution provides a useful analytical test for numerical codes that include a proton-electron mass ratio as a fundamental constant, such as for particle in cell (PIC) codes. The integral equation is used to delineate the physical characteristics of ion acoustic traveling waves consisting of hot electron and cold proton fluids.

  20. Beyond City Sidewalks: The Blind Traveler in a Rural Environment.

    ERIC Educational Resources Information Center

    Boone, Douglas; Boone, Christine

    1997-01-01

    The discovery-learning approach is being used with great success to teach blind persons orientation and mobility in rural environments. The problem-solving ability that accompanies this approach builds the self-confidence essential to independent travel. Discusses using a long cane, talking clock, and distance and environmental cues such as sun,…

  1. Tuning Multiple Motor Travel Via Single Motor Velocity

    PubMed Central

    Xu, Jing; Shu, Zhanyong; King, Stephen J.; Gross, Steven P.

    2012-01-01

    Microtubule-based molecular motors often work in small groups to transport cargos in cells. A key question in understanding transport (and its regulation in vivo) is to identify the sensitivity of multiple-motor-based motion to various single molecule properties. Whereas both single-motor travel distance and microtubule binding rate have been demonstrated to contribute to cargo travel, the role of single-motor velocity is yet to be explored. Here, we recast a previous theoretical study, and make explicit a potential contribution of velocity to cargo travel. We test this possibility experimentally, and demonstrate a strong negative correlation between single-motor velocity and cargo travel for transport driven by two motors. Our study thus discovers a previously unappreciated role of single-motor velocity in regulating multiple-motor transport. PMID:22672518

  2. Reversed theta sequences of hippocampal cell assemblies during backward travel.

    PubMed

    Cei, Anne; Girardeau, Gabrielle; Drieu, Céline; Kanbi, Karim El; Zugaro, Michaël

    2014-05-01

    Hippocampal cell assemblies coding for past, present and future events form theta-timescale (~100 ms) sequences that represent spatio-temporal episodes. However, the underlying mechanisms remain largely unknown. We recorded hippocampal and entorhinal cortical activity as rats experienced backward travel on a model train. Although the firing fields of place cells remained stable, the order in which they were activated in the theta sequence was reversed during backward travel. Thus, hippocampal cell assemblies coordinated their relative timing to correctly predict the sequential traversal of place fields in reverse order. At the single-cell level, theta phase represented distance traveled through the field, even though the head of the rat was oriented opposite to travel direction and entorhinal head-direction cells maintained their preferred firing direction. Our results challenge most theoretical models of theta sequence generation in the hippocampus.

  3. Evidence on global medical travel

    PubMed Central

    Záliš, Ladislav; Meurice, Christopher R; Hilton, Ian; Ly, Terry-Lisa; Zupan, Zorana; Hinrichs, Saba

    2015-01-01

    Abstract The potential benefits of travelling across national borders to obtain medical treatment include improved care, decreased costs and reduced waiting times. However, medical travel involves additional risks, compared to obtaining treatment domestically. We review the publicly-available evidence on medical travel. We suggest that medical travel needs to be understood in terms of its potential risks and benefits so that it can be evaluated against alternatives by patients who are seeking care. We propose three domains –quality standards, informed decision-making, economic and legal protection – in which better evidence could support the development of medical travel policies. PMID:26549906

  4. Evidence on global medical travel.

    PubMed

    Ruggeri, Kai; Záliš, Ladislav; Meurice, Christopher R; Hilton, Ian; Ly, Terry-Lisa; Zupan, Zorana; Hinrichs, Saba

    2015-11-01

    The potential benefits of travelling across national borders to obtain medical treatment include improved care, decreased costs and reduced waiting times. However, medical travel involves additional risks, compared to obtaining treatment domestically. We review the publicly-available evidence on medical travel. We suggest that medical travel needs to be understood in terms of its potential risks and benefits so that it can be evaluated against alternatives by patients who are seeking care. We propose three domains -quality standards, informed decision-making, economic and legal protection - in which better evidence could support the development of medical travel policies.

  5. Evidence on global medical travel.

    PubMed

    Ruggeri, Kai; Záliš, Ladislav; Meurice, Christopher R; Hilton, Ian; Ly, Terry-Lisa; Zupan, Zorana; Hinrichs, Saba

    2015-11-01

    The potential benefits of travelling across national borders to obtain medical treatment include improved care, decreased costs and reduced waiting times. However, medical travel involves additional risks, compared to obtaining treatment domestically. We review the publicly-available evidence on medical travel. We suggest that medical travel needs to be understood in terms of its potential risks and benefits so that it can be evaluated against alternatives by patients who are seeking care. We propose three domains -quality standards, informed decision-making, economic and legal protection - in which better evidence could support the development of medical travel policies. PMID:26549906

  6. The actual goals of geoethics

    NASA Astrophysics Data System (ADS)

    Nemec, Vaclav

    2014-05-01

    The most actual goals of geoethics have been formulated as results of the International Conference on Geoethics (October 2013) held at the geoethics birth-place Pribram (Czech Republic): In the sphere of education and public enlightenment an appropriate needed minimum know how of Earth sciences should be intensively promoted together with cultivating ethical way of thinking and acting for the sustainable well-being of the society. The actual activities of the Intergovernmental Panel of Climate Changes are not sustainable with the existing knowledge of the Earth sciences (as presented in the results of the 33rd and 34th International Geological Congresses). This knowledge should be incorporated into any further work of the IPCC. In the sphere of legislation in a large international co-operation following steps are needed: - to re-formulate the term of a "false alarm" and its legal consequences, - to demand very consequently the needed evaluation of existing risks, - to solve problems of rights of individuals and minorities in cases of the optimum use of mineral resources and of the optimum protection of the local population against emergency dangers and disasters; common good (well-being) must be considered as the priority when solving ethical dilemmas. The precaution principle should be applied in any decision making process. Earth scientists presenting their expert opinions are not exempted from civil, administrative or even criminal liabilities. Details must be established by national law and jurisprudence. The well known case of the L'Aquila earthquake (2009) should serve as a serious warning because of the proven misuse of geoethics for protecting top Italian seismologists responsible and sentenced for their inadequate superficial behaviour causing lot of human victims. Another recent scandal with the Himalayan fossil fraud will be also documented. A support is needed for any effort to analyze and to disclose the problems of the deformation of the contemporary

  7. Travelers with Disabilities and Medical Conditions

    MedlinePlus

    ... Claims Travel Tips Travel Bulletin Travel Checklist FAQ Disabilities and Medical Conditions To ensure your security, all ... other questions or concerns about traveling with a disability please contact passenger support . If you are approved ...

  8. Malaria: prevention in travellers

    PubMed Central

    Croft, Ashley

    2000-01-01

    Definition Malaria is caused by a protozoan infection of red blood cells with one of four species of the genus plasmodium: P falciparum, P vivax, P ovale, or P malariae.1 Clinically, malaria may present in different ways, but it is usually characterised by fever (which may be swinging), tachycardia, rigors, and sweating. Anaemia, hepatosplenomegaly, cerebral involvement, renal failure, and shock may occur. Incidence/prevalence Each year there are 300-500 million clinical cases of malaria. About 40% of the world's population is at risk of acquiring the disease.23 Each year 25-30 million people from non-tropical countries visit areas in which malaria is endemic,4 of whom between 10 000 and 30 000 contract malaria.5 Aetiology/risk factors Malaria is mainly a rural disease, requiring standing water nearby. It is transmitted by bites6 from infected female anopheline mosquitoes,7 mainly at dusk and during the night.18 In cities, mosquito bites are usually from female culicene mosquitoes, which are not vectors of malaria.9 Malaria is resurgent in most tropical countries and the risk to travellers is increasing.10 Prognosis Ninety per cent of travellers who contract malaria do not become ill until after they return home.5 “Imported malaria” is easily treated if diagnosed promptly, and it follows a serious course in only about 12% of people.1112 The most severe form of the disease is cerebral malaria, with a case fatality rate in adult travellers of 2-6%,3 mainly because of delays in diagnosis.5 Aims To reduce the risk of infection; to prevent illness and death. Outcomes Rates of malarial illness and death, and adverse effects of treatment. Proxy measures include number of mosquito bites and number of mosquitoes in indoor areas. We found limited evidence linking number of mosquito bites and risk of malaria.13 Methods Clinical Evidence search and appraisal in November 1999. We reviewed all identified systematic reviews and randomised controlled trials (RCTs

  9. 2001 New York State NHTS: Travel Patterns of Special Populations

    SciTech Connect

    Hu, Patricia S; Reuscher, Tim

    2010-03-01

    Policymakers rely on transportation statistics, including data on personal travel behavior, to formulate strategic transportation policies, and to improve the safety and efficiency of the U.S. transportation system. Data on personal travel trends are needed to examine the reliability, efficiency, capacity, and flexibility of the Nation's transportation system to meet current demands and accommodate future demands; to assess the feasibility and efficiency of alternative congestion-alleviating technologies (e.g., high-speed rail, magnetically levitated trains, intelligent vehicle and highway systems); to evaluate the merits of alternative transportation investment programs; and to assess the energy-use and air-quality impacts of various policies. To address these data needs, the U.S. Department of Transportation (USDOT) initiated an effort in 1969 to collect detailed data on personal travel. The 1969 survey was the first Nationwide Personal Transportation Survey (NPTS). The survey was conducted again in 1977, 1983, 1990, 1995, and 2001. Data on daily travel were collected in 1969, 1977, 1983, 1990 and 1995. Longer-distance travel was collected in 1977 and 1995. The 2001 National Household Travel Survey (NHTS) collected both daily and longer-distance trips in one survey. The 2001 survey was sponsored by three USDOT agencies: Federal Highway Administration (FHWA), Bureau of Transportation Statistics (BTS), and National Highway Traffic Safety Administration (NHTSA). The primary objective of the survey was to collect trip-based data on the nature and characteristics of personal travel so that the relationships between the characteristics of personal travel and the demographics of the traveler can be established. Commercial and institutional travel was not part of the survey. New York State participated in the 2001 NHTS by procuring additional 12,000 sample households. These additional sample households allowed New York State to address transportation planning issues

  10. Energetic and biomechanical constraints on animal migration distance.

    PubMed

    Hein, Andrew M; Hou, Chen; Gillooly, James F

    2012-02-01

    Animal migration is one of the great wonders of nature, but the factors that determine how far migrants travel remain poorly understood. We present a new quantitative model of animal migration and use it to describe the maximum migration distance of walking, swimming and flying migrants. The model combines biomechanics and metabolic scaling to show how maximum migration distance is constrained by body size for each mode of travel. The model also indicates that the number of body lengths travelled by walking and swimming migrants should be approximately invariant of body size. Data from over 200 species of migratory birds, mammals, fish, and invertebrates support the central conclusion of the model - that body size drives variation in maximum migration distance among species through its effects on metabolism and the cost of locomotion. The model provides a new tool to enhance general understanding of the ecology and evolution of migration. PMID:22093885

  11. Energetic and biomechanical constraints on animal migration distance.

    PubMed

    Hein, Andrew M; Hou, Chen; Gillooly, James F

    2012-02-01

    Animal migration is one of the great wonders of nature, but the factors that determine how far migrants travel remain poorly understood. We present a new quantitative model of animal migration and use it to describe the maximum migration distance of walking, swimming and flying migrants. The model combines biomechanics and metabolic scaling to show how maximum migration distance is constrained by body size for each mode of travel. The model also indicates that the number of body lengths travelled by walking and swimming migrants should be approximately invariant of body size. Data from over 200 species of migratory birds, mammals, fish, and invertebrates support the central conclusion of the model - that body size drives variation in maximum migration distance among species through its effects on metabolism and the cost of locomotion. The model provides a new tool to enhance general understanding of the ecology and evolution of migration.

  12. Cool flame quench distances

    NASA Technical Reports Server (NTRS)

    Ryason, P. R.; Hirsch, E.

    1974-01-01

    The results of a brief experimental investigation are presented which confirm the expectation that cool flame quenching distances should be larger than hot flame quenching distances. It is also discovered that whereas quenching distances for hot flames reach their minimum values near stoichiometric conditions, cool flame quenching distances are least under rich conditions. Rich conditions are well known to favor cool flame formation.

  13. Facilitating Distance Education.

    ERIC Educational Resources Information Center

    Rossman, Mark H., Ed.; Rossman, Maxine E., Ed.

    1995-01-01

    This collection of articles on distance learning reflects the perspectives and concerns of the learner and the facilitator of learning in distance education setting. Eight chapters are included: (1) "The Evolution and Advantages of Distance Education" (John E. Cantelon) traces the history of distance education and demonstrates how it transcends…

  14. Training for Distance Teaching through Distance Learning.

    ERIC Educational Resources Information Center

    Cadorath, Jill; Harris, Simon; Encinas, Fatima

    2002-01-01

    Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

  15. Culture, distance, and threat perception: comment on Stamps (2011).

    PubMed

    Su, Yin; Zheng, Yu; Li, Shu

    2012-12-01

    Stamps found that the effects of visual cues on the perception of threat decrease with distance, even when the range of distance is extended to 45 m. The present comment suggests that the findings Stamps obtained in a Western culture may not hold in other cultures. The robustness of these findings might be improved by using real targets at actual physical distances and "necessarily high" threats. Further studies are needed to examine whether other dimensions of psychological distance have the same effect on threat perception as does spatial distance. There is also a need to examine whether perceived threats have a significant effect on the perception of spatial distance.

  16. Modified Video Course Methodology for Distance Learning.

    ERIC Educational Resources Information Center

    Springer, Stephen B.

    In recent years, colleges have made extensive efforts to provide distance learning opportunities for adult students. At Southwest Texas State University, a required course in the Occupational Education program has been delivered in a modified video format. The video was made of an actual class being taught in a production studio. The main…

  17. Car Stopping Distance on a Tabletop

    ERIC Educational Resources Information Center

    Haugland, Ole Anton

    2013-01-01

    Stopping distances in car braking can be an intriguing topic in physics teaching. It illustrates some basic principles of physics, and sheds valuable light on students' attitude towards aggressive driving. Due to safety considerations, it can be difficult to make experiments with actual car braking. (Contains 2 figures.)

  18. Travel Demand Modeling

    SciTech Connect

    Southworth, Frank; Garrow, Dr. Laurie

    2011-01-01

    This chapter describes the principal types of both passenger and freight demand models in use today, providing a brief history of model development supported by references to a number of popular texts on the subject, and directing the reader to papers covering some of the more recent technical developments in the area. Over the past half century a variety of methods have been used to estimate and forecast travel demands, drawing concepts from economic/utility maximization theory, transportation system optimization and spatial interaction theory, using and often combining solution techniques as varied as Box-Jenkins methods, non-linear multivariate regression, non-linear mathematical programming, and agent-based microsimulation.

  19. Time, travel and infection.

    PubMed

    Cliff, Andrew; Haggett, Peter

    2004-01-01

    The collapse of geographical space over the last 200 years has had profound effects on the circulation of human populations and on the transfer of infectious diseases. Three examples are used to illustrate the process: (a) the impact of the switch from sail to steamships in importing measles into Fiji over a 40-year period; (b) changes in measles epidemic behaviour in Iceland over a 150-year period; and (c) changes in the spread of cholera within the United States over a 35-year period. In each case, the link between time, travel and disease has been an intimate one.

  20. Travel determinants and multi-scale transferability of national activity patterns to local populations

    SciTech Connect

    Henson, Kriste M; Gou; ias, Konstadinos G

    2010-11-30

    The ability to transfer national travel patterns to a local population is of interest when attempting to model megaregions or areas that exceed metropolitan planning organization (MPO) boundaries. At the core of this research are questions about the connection between travel behavior and land use, urban form, and accessibility. As a part of this process, a group of land use variables have been identified to define activity and travel patterns for individuals and households. The 2001 National Household Travel Survey (NHTS) participants are divided into categories comprised of a set of latent cluster models representing persons, travel, and land use. These are compared to two sets of cluster models constructed for two local travel surveys. Comparison of means statistical tests are used to assess differences among sociodemographic groups residing in localities with similar land uses. The results show that the NHTS and the local surveys share mean population activity and travel characteristics. However, these similarities mask behavioral heterogeneity that are shown when distributions of activity and travel behavior are examined. Therefore, data from a national household travel survey cannot be used to model local population travel characteristics if the goal to model the actual distributions and not mean travel behavior characteristics.

  1. Patterns of measles transmission among airplane travelers.

    PubMed

    Edelson, Paul J

    2012-09-01

    With advanced air handling systems on modern aircraft and the high level of measles immunity in many countries, measles infection in air travelers may be considered a low-risk event. However, introduction of measles into countries where transmission has been controlled or eliminated can have substantial consequences both for the use of public health resources and for those still susceptible. In an effort to balance the relatively low likelihood of disease transmission among largely immune travelers and the risk to the public health of the occurrence of secondary cases resulting from importations, criteria in the United States for contact investigations for measles exposures consider contacts to be those passengers who are seated within 2 rows of the index case. However, recent work has shown that cabin air flow may not be as reliable a barrier to the spread of measles virus as previously believed. Along with these new studies, several reports have described measles developing after travel in passengers seated some distance from the index case. To understand better the potential for measles virus to spread on an airplane, reports of apparent secondary cases occurring in co-travelers of passengers with infectious cases of measles were reviewed. Medline™ was searched for articles in all languages from 1946 to week 1 of March 2012, using the search terms "measles [human] or rubeola" and ("aircraft" or "airplane" or "aeroplane" or "aviation" or "travel" or "traveler" or "traveller"); 45 citations were returned. Embase™ was searched from 1988 to week 11 2012, using the same search strategy; 95 citations were returned. Papers were included in this review if they reported secondary cases of measles occurring in persons traveling on an airplane on which a person or persons with measles also flew, and which included the seating location of both the index case(s) and the secondary case(s) on the plane. Nine reports, including 13 index cases and 23 apparent secondary cases

  2. Patterns of measles transmission among airplane travelers.

    PubMed

    Edelson, Paul J

    2012-09-01

    With advanced air handling systems on modern aircraft and the high level of measles immunity in many countries, measles infection in air travelers may be considered a low-risk event. However, introduction of measles into countries where transmission has been controlled or eliminated can have substantial consequences both for the use of public health resources and for those still susceptible. In an effort to balance the relatively low likelihood of disease transmission among largely immune travelers and the risk to the public health of the occurrence of secondary cases resulting from importations, criteria in the United States for contact investigations for measles exposures consider contacts to be those passengers who are seated within 2 rows of the index case. However, recent work has shown that cabin air flow may not be as reliable a barrier to the spread of measles virus as previously believed. Along with these new studies, several reports have described measles developing after travel in passengers seated some distance from the index case. To understand better the potential for measles virus to spread on an airplane, reports of apparent secondary cases occurring in co-travelers of passengers with infectious cases of measles were reviewed. Medline™ was searched for articles in all languages from 1946 to week 1 of March 2012, using the search terms "measles [human] or rubeola" and ("aircraft" or "airplane" or "aeroplane" or "aviation" or "travel" or "traveler" or "traveller"); 45 citations were returned. Embase™ was searched from 1988 to week 11 2012, using the same search strategy; 95 citations were returned. Papers were included in this review if they reported secondary cases of measles occurring in persons traveling on an airplane on which a person or persons with measles also flew, and which included the seating location of both the index case(s) and the secondary case(s) on the plane. Nine reports, including 13 index cases and 23 apparent secondary cases

  3. Air travel and the risk of thromboembolism.

    PubMed

    Gavish, Israel; Brenner, Benjamin

    2011-04-01

    Almost two billion people use commercial aircraft annually. Long-haul flights are taken by over 300 million people. A serious complication of long-distance travel (or prolonged time of flight) is thromboembolism. The real incidence of the problem is difficult to evaluate since there is no consensus about the diagnostic tests or limitation of time after landing connected to the VTE complication. A direct relation between VTE incidence and long-distance flights has been documented. The risk for DVT is 3-12% in a long-haul flight. The pathophysiologic changes that increase VTE risk at flight are stasis (sitting in crowded condition), hypoxia in the airplane cabin, and dehydration. Individual risk factors for air travel-related VTE include age over 40 years, gender (female), women who use oral contraceptives, varicose veins in lower limbs, obesity and genetic thrombophilia. Prevention measures include environmental protection such as keeping the pressure inside the airplane cabinet in hypobaric condition, avoiding dehydration and prolonged sitting. For individuals at increased risk, venous blood stasis can be reduced by wearing elastic stockings and prophylactic use of low-molecular-weight heparin. PMID:21057984

  4. Traveling-Wave Tubes

    NASA Technical Reports Server (NTRS)

    Kory, Carol L.

    1998-01-01

    The traveling-wave tube (TWT) is a vacuum device invented in the early 1940's used for amplification at microwave frequencies. Amplification is attained by surrendering kinetic energy from an electron beam to a radio frequency (RF) electromagnetic wave. The demand for vacuum devices has been decreased largely by the advent of solid-state devices. However, although solid state devices have replaced vacuum devices in many areas, there are still many applications such as radar, electronic countermeasures and satellite communications, that require operating characteristics such as high power (Watts to Megawatts), high frequency (below 1 GHz to over 100 GHz) and large bandwidth that only vacuum devices can provide. Vacuum devices are also deemed irreplaceable in the music industry where musicians treasure their tube-based amplifiers claiming that the solid-state and digital counterparts could never provide the same "warmth" (3). The term traveling-wave tube includes both fast-wave and slow-wave devices. This article will concentrate on slow-wave devices as the vast majority of TWTs in operation fall into this category.

  5. [Travel-associated pneumonias].

    PubMed

    Geerdes-Fenge, H F

    2014-10-01

    Respiratory infections are responsible for up to 11% of febrile infections in travellers or immigrants from tropical and subtropical regions. The main pathogens are the same as in temperate climate zones: Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, influenza viruses, Legionella pneumophila. However, some pulmonary diseases can be attributed to bacterial, parasitic, viral or fungal pathogens that are endemic in tropical and subtropical regions. The most commonly imported infections are malaria, dengue, and tuberculosis. Pulmonary symptoms and eosinophilia in returning travellers and migrants may be caused by several parasitic infections such as Katayama syndrome, Loeffler syndrome, tropical pulmonary eosinophilia, amebiasis, paragonimiasis, echinococcosis, and toxocariasis. In Asia, Tsutsugamushi fever is transmitted by chiggers, spotted fever rickettsiae are transmitted by ticks. Transmission of zoonotic diseases occurs mainly via contact with infected animals or their excretions, human-to-human transmission is generally rare: MERS-CoA (dromedary camels), pulmonary hantavirus infection (rodents), tularemia (rabbits and hares), leptospirosis (rats), Q-fever (sheep and goats), very rarely anthrax (hides of ruminants) and pest (infected rats and wildlife). Inhalation of contaminated dust can cause infections with dimorphic fungi: histoplasmosis (bat guano) and coccidioidomycosis in America and parts of Africa, blastomycosis in America. Some infections can cause symptoms years after a stay in tropical or subtropical regions (melioidosis, tuberculosis, histoplasmosis, schistosomiasis-associated pulmonary hypertension). Noninfectious respiratory diseases caused by inhalation of high amounts of air pollution or toxic dusts may also be considered. PMID:25290923

  6. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  7. The ideal subject distance for passport pictures.

    PubMed

    Verhoff, Marcel A; Witzel, Carsten; Kreutz, Kerstin; Ramsthaler, Frank

    2008-07-01

    In an age of global combat against terrorism, the recognition and identification of people on document images is of increasing significance. Experiments and calculations have shown that the camera-to-subject distance - not the focal length of the lens - can have a significant effect on facial proportions. Modern passport pictures should be able to function as a reference image for automatic and manual picture comparisons. This requires a defined subject distance. It is completely unclear which subject distance, in the taking of passport photographs, is ideal for the recognition of the actual person. We show here that the camera-to-subject distance that is perceived as ideal is dependent on the face being photographed, even if the distance of 2m was most frequently preferred. So far the problem of the ideal camera-to-subject distance for faces has only been approached through technical calculations. We have, for the first time, answered this question experimentally with a double-blind experiment. Even if there is apparently no ideal camera-to-subject distance valid for every face, 2m can be proposed as ideal for the taking of passport pictures. The first step would actually be the determination of a camera-to-subject distance for the taking of passport pictures within the standards. From an anthropological point of view it would be interesting to find out which facial features allow the preference of a shorter camera-to-subject distance and which allow the preference of a longer camera-to-subject distance. PMID:18450396

  8. Evaluation of the returned traveler.

    PubMed Central

    Hill, D. R.

    1992-01-01

    Recognition of clinical syndromes in returned travelers is an important part of providing care to international travelers. The first step is to take a history with attention to pre-travel preventive measures, the patient's itinerary, and potential exposure to infectious agents. The patient should then be examined to document physical signs, such as fever, rash, or hepatosplenomegaly, and to have basic laboratory data obtained. This evaluation will provide most physicians with the necessary information to generate a differential diagnosis. Each diagnosis should be matched against the incubation period of the disease, the geographic location of illness, the frequency of illness in returned travelers, and the pre-travel preventive measures. Careful attention to these aspects of patient care should result in the appropriate diagnosis and therapeutic intervention for the ill returned traveler. PMID:1290276

  9. [Cardiovascular risk for the traveler].

    PubMed

    Touze, J E; Fourcade, L; Heno, P; Van de Walle, J P; Mafart, B; N'Guyen-Hai

    1997-01-01

    The incidence of cardiovascular events during travel is rising with the age of the population and number of traveling seniors. Cardiovascular events are the second most frequent reason for medical evacuation and the cause of 50% of deaths recorded during commercial air travel. In most cases the underlying disorder is coronary artery disease which is readily destabilized by stress and fatigue associated with travel. Inflight conditions that can cause problems include altitude-related hypoxia, pressurization, and cramped seating in most sections of the plane. Upon arrival the traveler is exposed to a variety of climatic, food, and environmental factors that can trigger manifestations of latent heart disease. Prophylactic drugs for tropical infectious disease (especially antimalarials of the quinidine group) should be used with caution due to possible adverse interaction with medications used to treat heart disease. A pre-travel examination is necessary to ascertain cardiovascular status and define simple preventive precautions.

  10. Traveling waves in visual cortex.

    PubMed

    Sato, Tatsuo K; Nauhaus, Ian; Carandini, Matteo

    2012-07-26

    Electrode recordings and imaging studies have revealed that localized visual stimuli elicit waves of activity that travel across primary visual cortex. Traveling waves are present also during spontaneous activity, but they can be greatly reduced by widespread and intensive visual stimulation. In this Review, we summarize the evidence in favor of these traveling waves. We suggest that their substrate may lie in long-range horizontal connections and that their functional role may involve the integration of information over large regions of space.

  11. Natural and built environmental exposures on children's active school travel: A Dutch global positioning system-based cross-sectional study.

    PubMed

    Helbich, Marco; Emmichoven, Maarten J Zeylmans van; Dijst, Martin J; Kwan, Mei-Po; Pierik, Frank H; Vries, Sanne I de

    2016-05-01

    Physical inactivity among children is on the rise. Active transport to school (ATS), namely walking and cycling there, adds to children's activity level. Little is known about how exposures along actual routes influence children's transport behavior. This study examined how natural and built environments influence mode choice among Dutch children aged 6-11 years. 623 school trips were tracked with global positioning system. Natural and built environmental exposures were determined by means of a geographic information system and their associations with children's active/passive mode choice were analyzed using mixed models. The actual commuted distance is inversely associated with ATS when only personal, traffic safety, and weather features are considered. When the model is adjusted for urban environments, the results are reversed and distance is no longer significant, whereas well-connected streets and cycling lanes are positively associated with ATS. Neither green space nor weather is significant. As distance is not apparent as a constraining travel determinant when moving through urban landscapes, planning authorities should support children's ATS by providing well-designed cities.

  12. Natural and built environmental exposures on children's active school travel: A Dutch global positioning system-based cross-sectional study.

    PubMed

    Helbich, Marco; Emmichoven, Maarten J Zeylmans van; Dijst, Martin J; Kwan, Mei-Po; Pierik, Frank H; Vries, Sanne I de

    2016-05-01

    Physical inactivity among children is on the rise. Active transport to school (ATS), namely walking and cycling there, adds to children's activity level. Little is known about how exposures along actual routes influence children's transport behavior. This study examined how natural and built environments influence mode choice among Dutch children aged 6-11 years. 623 school trips were tracked with global positioning system. Natural and built environmental exposures were determined by means of a geographic information system and their associations with children's active/passive mode choice were analyzed using mixed models. The actual commuted distance is inversely associated with ATS when only personal, traffic safety, and weather features are considered. When the model is adjusted for urban environments, the results are reversed and distance is no longer significant, whereas well-connected streets and cycling lanes are positively associated with ATS. Neither green space nor weather is significant. As distance is not apparent as a constraining travel determinant when moving through urban landscapes, planning authorities should support children's ATS by providing well-designed cities. PMID:27010106

  13. Skin lesions in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz; Jerzemowski, Janusz

    2015-01-01

    Skin lesions, apart from diarrhoeas, fever of unknown origin, and respiratory tract infections belong to the most frequent medical problems in travellers returned from tropical and subtropical destinations, accounting more than 10% of reported cases. Most dermatoses have their clinical onset during travel, although some of them can occur after return. Travel-related dermatological problems can have a wide spectrum of clinical picture, from macular, popular or nodular rash, linear and migratory lesions, to plaques, vesicles, bullae, erosions or ulcers. Skin conditions in returning travellers may be of infectious and non-infectious aetiologies. Infectious lesions may be originally tropical (e.g. dengue, chikungunya, schistosomiasis, leishmaniasis, myiasis, tungiasis, loiasis), although the majority are cosmopolitan (arthropod bites, sunburns, allergic rashes). The evaluation of skin lesions depends on many factors, including immune status of patients, use of medicines, exposure on health hazards (fauna, flora, risky behaviours), as well as the time, duration and location of travel. As the number of travellers to tropical and subtropical destinations has been continuously rising, the number of skin illnesses has also been increasing. This means that specialists in travel medicine need to extend their knowledge of epidemiology, clinical features and diagnosis of travel-related health problems including skin lesions in returning travellers. PMID:26394319

  14. Skin lesions in returning travellers.

    PubMed

    Korzeniewski, Krzysztof; Juszczak, Dariusz; Jerzemowski, Janusz

    2015-01-01

    Skin lesions, apart from diarrhoeas, fever of unknown origin, and respiratory tract infections belong to the most frequent medical problems in travellers returned from tropical and subtropical destinations, accounting more than 10% of reported cases. Most dermatoses have their clinical onset during travel, although some of them can occur after return. Travel-related dermatological problems can have a wide spectrum of clinical picture, from macular, popular or nodular rash, linear and migratory lesions, to plaques, vesicles, bullae, erosions or ulcers. Skin conditions in returning travellers may be of infectious and non-infectious aetiologies. Infectious lesions may be originally tropical (e.g. dengue, chikungunya, schistosomiasis, leishmaniasis, myiasis, tungiasis, loiasis), although the majority are cosmopolitan (arthropod bites, sunburns, allergic rashes). The evaluation of skin lesions depends on many factors, including immune status of patients, use of medicines, exposure on health hazards (fauna, flora, risky behaviours), as well as the time, duration and location of travel. As the number of travellers to tropical and subtropical destinations has been continuously rising, the number of skin illnesses has also been increasing. This means that specialists in travel medicine need to extend their knowledge of epidemiology, clinical features and diagnosis of travel-related health problems including skin lesions in returning travellers.

  15. Dengue fever in international travelers.

    PubMed

    Jelinek, T

    2000-07-01

    Dengue virus infection is becoming increasingly recognized as one of the world's major emerging infectious diseases. Although only a few systematic studies have been conducted to assess the incidence and clinical course of dengue fever in travelers, it is now possible to estimate risk factors for travelers to areas of endemicity. Dengue virus and its vector, Aedes mosquitoes, benefit from human habitation and travel-related aspects of human behavior. Thus, travelers serve an important double role as potential victims of the disease and as vehicles for further spread of dengue.

  16. Distance-Based Opportunistic Mobile Data Offloading.

    PubMed

    Lu, Xiaofeng; Lio, Pietro; Hui, Pan

    2016-06-15

    Cellular network data traffic can be offload onto opportunistic networks. This paper proposes a Distance-based Opportunistic Publish/Subscribe (DOPS) content dissemination model, which is composed of three layers: application layer, decision-making layer and network layer. When a user wants new content, he/she subscribes on a subscribing server. Users having the contents decide whether to deliver the contents to the subscriber based on the distance information. If in the meantime a content owner has traveled further in the immediate past time than the distance between the owner and the subscriber, the content owner will send the content to the subscriber through opportunistic routing. Simulations provide an evaluation of the data traffic offloading efficiency of DOPS.

  17. Distance-Based Opportunistic Mobile Data Offloading

    PubMed Central

    Lu, Xiaofeng; Lio, Pietro; Hui, Pan

    2016-01-01

    Cellular network data traffic can be offload onto opportunistic networks. This paper proposes a Distance-based Opportunistic Publish/Subscribe (DOPS) content dissemination model, which is composed of three layers: application layer, decision-making layer and network layer. When a user wants new content, he/she subscribes on a subscribing server. Users having the contents decide whether to deliver the contents to the subscriber based on the distance information. If in the meantime a content owner has traveled further in the immediate past time than the distance between the owner and the subscriber, the content owner will send the content to the subscriber through opportunistic routing. Simulations provide an evaluation of the data traffic offloading efficiency of DOPS. PMID:27314361

  18. Solar wind travel time

    NASA Astrophysics Data System (ADS)

    Russell, C. T.

    A useful rule of thumb in solar terrestrial studies is that the solar wind travels 4 Earth radii (RE) per minute. Long-term studies of solar wind velocity [e.g., Luhmann et al., 1993; 1994] show that the median velocity is about 420 km/s, corresponding to 3.96 RE min-1. The quartiles are about 370 km/s and 495 km/s, corresponding to 3.48 Re min-1 and 4.66 Re min-1 respectively. This number helps estimate the delays expected when observing a discontinuity at a solar wind monitor; one example is ISEE-3 when it was at the forward libration point (about 60 min). It is also helpful for estimating how much time passes before the dayside magnetosphere is compressed as denser solar wind flows by (about 2.5 min).

  19. [Travel and skin diseases].

    PubMed

    Stüttgen, G

    1992-02-20

    The problem "travelling and dermatological diseases" is presented as a temporary change of place with associated changes in ecological conditions. Latent dermatoses may be provoked--but full-blown dermatoses may also improve with no specific treatment (climatic therapy of neurodermatitis). Physiological changes at the surface of the skin brought about by, for example, temperature or the effects of solar radiation, may allow fungal, bacterial or viral infections to develop. Direct contact with the living environment on land or in the water, in particular in the tropics, can lead to the development of diseases. Some dermatoses have a lengthy latency and develop only later at home. Recommendations for general and specific prophylaxis and treatment are made.

  20. Traveling wave tube circuit

    NASA Technical Reports Server (NTRS)

    Connolly, D. J. (Inventor)

    1978-01-01

    A traveling wave tube (TWT) has a slow wave structure (SWS) which is severed into two or more sections. A signal path, connects the end of an SWS section to the beginning of the following SWS section. The signal path comprises an impedance matching coupler (IMC), followed by an isolator, a variable phase shifter, and a second IMC. The aggregate band pass characteristic of the components in the signal path is chosen to reject, or strongly attenuate, all frequencies outside the desired operating frequency range of the TWT and yet pass, with minimal attenuation in the forward direction, all frequencies within the desired operating frequency range. The isolator is chosen to reject, or strongly attenuate, waves, of all frequencies, which propagate in the backward direction. The aggregate phase shift characteristic of the components in the signal path is chosen to apply signal power to the beginning of the following SWS section with the phase angle yielding maximum efficiency.

  1. Going the Distance

    ERIC Educational Resources Information Center

    Waters, John K.

    2012-01-01

    Whoever said "Distance education begins in the 10th row" was taking a jab at the comatose kids at the back of his classroom, but the comment also taps into the old image of distance learners as disengaged themselves. That was then. Today, distance-learning programs are booming, in part due to demographic realities but also because recent advances…

  2. Foundations of Distance Education.

    ERIC Educational Resources Information Center

    Morabito, Margaret Gorts

    The foundations, development, and delivery of distance education were examined through a literature review and first-hand experience in administration and teaching in an international online school. The evolution of distance education was traced from the 1800s, when it was a print-based method of instruction conducted at a distance, through the…

  3. Distance Education Research.

    ERIC Educational Resources Information Center

    Curran, Chris

    1983-01-01

    Reviews six papers from the Open University Distance Education Research Group which cover the following topics: the credibility of distance education, admission systems, distance methods in adult basic education, the Universidad Estatal a Distancia (Costa Rica), Radio Ecca (Canary Islands), and the Open University (Great Britain). (EAO)

  4. Making Distance Education Borderless.

    ERIC Educational Resources Information Center

    Srisa-An, Wichit

    1997-01-01

    Begins with a tribute to Professor G. Ram Reddy (founder of Indira Gandhi National Open University), then focuses on enhancing the role of open universities in providing borderless distance education. Highlights include the need for open distance-education; philosophy and vision; the distance teaching system; the role of information technology;…

  5. Throwing patterns used by collegiate baseball players in actual games.

    PubMed

    Barrett, David D; Burton, Allen W

    2002-03-01

    The form of 3,684 throws made by 100 players in 7 collegiate baseball games was examined in relation to position, distance, and active and inactive situations. All throws made from the first pitch to the last out for 94 half innings were videotaped from the stands. The results showed that the interrater reliability of task, environment, and performance measures were all acceptable to excellent (percentage of agreement was at least 80%), indicating that qualitative aspects of throwing can be reliably measured in an actual sport context. Alternatives to the most advanced pattern were observed at least half the time for catchers and infielders at most distances in both active and inactive situations andfor pitchers and outfielders only in inactive situations.

  6. Subsurface Supergranular Vertical Flows as Measured Using Large Distance Separations in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.; Hanasoge, S. M.

    2012-01-01

    As large-distance rays (say, 10 - 24deg) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows within a few Mm of the solar surface. All previous analyses of supergranulation have used smaller separations and have been hampered by the difficulty of separating the horizontal and vertical flow components. We find that the large-separation travel times associated with supergranulation cannot be studied using the standard phase-speed filters of time-distance helioseismology. These filters, whose use is based upon a refractive model of the perturbations, reduce the resultant travel time signal by at least an order of magnitude at some distances. More effective filters are derived. Modeling suggests that the center-annulus travel-time difference [outward-going time minus inward-going time] in the separation range delta= 10 - 24deg is insensitive to the horizontally diverging flow from the centers of the supergranules and should lead to a constant signal from the vertical flow. Our measurement of this quantity, 5.1+/-0.1 seconds, is constant over the distance range. This magnitude of the signal cannot be caused by the level of upflow at cell centers seen at the photosphere of 10 ms(exp-1) extended in depth. It requires the vertical flow to increase with depth. A simple Gaussian model of the increase with depth implies a peak upward flow of 240 ms(exp-1) at a depth of 2.3 Mm and a peak horizontal flow of 700 ms(exp-1) at a depth of 1.6 Mm.

  7. Subsurface Supergranular Vertical Flows as Measured Using Large Distance Separations in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Hanasoge, S. M.

    2012-01-01

    As large-distance rays (say, 10-24 deg) approach the solar surface approximately vertically, travel times measured from surface pairs for these large separations are mostly sensitive to vertical flows, at least for shallow flows within a few Mm of the solar surface. All previous analyses of supergranulation have used smaller separations and have been hampered by the difficulty of separating the horizontal and vertical flow components. We find that the large separation travel times associated with upergranulation cannot be studied using the standard phase-speed filters of time-distance helioseismology. These filters, whose use is based upon a refractive model of the perturbations,reduce the resultant travel time signal by at least an order of magnitude at some distances. More effective filters are derived. Modeling suggests that the center-annulus travel time difference in the separation range 10-24 deg is insensitive to the horizontally diverging flow from the centers of the supergranules and should lead to a constant signal from the vertical flow. Our measurement of this quantity for the average supergranule, 5.1 s, is constant over the distance range. This magnitude of signal cannot be caused by the level of upflow at cell centers seen at the photosphere of 10 m/s extended in depth. It requires the vertical flow to increase with depth. A simple Gaussian model of the increase with depth implies a peak upward flow of 240 m/s at a depth of 2.3 Mm and a peak horizontal flow of 700 m/s at a depth of 1.6 Mm.

  8. Sensitivity of ray travel times

    NASA Astrophysics Data System (ADS)

    Smirnov, I. P.; Virovlyansky, A. L.; Zaslavsky, G. M.

    2002-09-01

    Ray in a waveguide can be considered as a trajectory of the corresponding Hamiltonian system, which appears to be chaotic in a nonuniform environment. From the experimental and practical viewpoints, the ray travel time is an important characteristic that, in some way, involves an information about the waveguide condition. It is shown that the ray travel time as a function of the initial momentum and propagation range in the unperturbed waveguide displays a scaling law. Some properties of the ray travel time predicted by this law still persist in periodically nonuniform waveguides with chaotic ray trajectories. As examples we consider few models with special attention to the underwater acoustic waveguide. It is demonstrated for a deep ocean propagation model that even under conditions of ray chaos the ray travel time is determined, to a considerable extent, by the coordinates of the ray endpoints and the number of turning points, i.e., by a topology of the ray path. We show how the closeness of travel times for rays with equal numbers of turning points reveals itself in ray travel time dependencies on the starting momentum and on the depth of the observation point. It has been shown that the same effect is associated with the appearance of the gap between travel times of chaotic and regular rays. The manifestation of the stickiness (the presence of such parts in a chaotic trajectory where the latter exhibits an almost regular behavior) in ray travel times is discussed.

  9. Travel and Adult Transformative Learning

    ERIC Educational Resources Information Center

    Lindstrom, Steven K.

    2011-01-01

    This phenomenological research study examines the lived experience of individual adult transformation in the context of travel. Adults throughout history have experienced profound personal and perception changes as a result of significant travel events. Transformative learning occurs through experience, crisis, and reflection, all of which are…

  10. Winter Wilderness Travel and Camping.

    ERIC Educational Resources Information Center

    Gilchrest, Norman

    Knowledge and skill are needed for safe and enjoyable travel and camping in the wilderness in winter. The beauty of snow and ice, reduced human use, and higher tolerance of animals toward humans make the wilderness attractive during winter. The uniqueness of winter travel presents several challenges that are not present in other seasons. Safety is…

  11. 49 CFR 229.55 - Piston travel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Piston travel. 229.55 Section 229.55... Piston travel. (a) Brake cylinder piston travel shall be sufficient to provide brake shoe clearance when... piston travel may not exceed 11/2 inches less than the total possible piston travel. The total...

  12. 49 CFR 229.55 - Piston travel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Piston travel. 229.55 Section 229.55... Piston travel. (a) Brake cylinder piston travel shall be sufficient to provide brake shoe clearance when... piston travel may not exceed 11/2 inches less than the total possible piston travel. The total...

  13. [Travel and patients with allergies].

    PubMed

    Miltgen, J; N'Guyen, G; Cuguilliere, A; Marotel, C; Bonnet, D

    1997-01-01

    By changing their surroundings and lifestyle, travelers with allergic conditions exposed themselves to new risks. The main perennial allergens are house dust mites which thrive in tropical areas and can be especially sensitizing. The risk of seasonal reactions to grass-pollens varies from region to region. Reactions to some highly sensitizing respiratory allergens can occur in travelers who return to regions where they were previously exposed. Subjects with food allergies should beware of possible reactions to ingredients in exotic dishes. The bites of several insects can cause anaphylactic reactions. Some medications required for tropical travel (e.g. antimalarial drugs) can trigger severe hypersensitivity reactions. Avoidance of allergens is more difficult during travel. Travelers with allergic conditions should carry alert identification cards and medications for routine as well as emergency treatment including self-injectable adrenaline.

  14. Stories from Students in Their First Semester of Distance Learning

    ERIC Educational Resources Information Center

    Brown, Mark; Hughes, Helen; Keppell, Mike; Hard, Natasha; Smith, Liz

    2015-01-01

    Online and distance learning is becoming increasingly common. Some would say it has quickly become the preferred or "new normal" mode of study throughout the world. However, surprisingly little is known about what actually happens to first year distance students once they have enrolled in tertiary institutions; what motivates them and…

  15. President's Address: Travel Medicine and Principles of Safe Travel

    PubMed Central

    DuPont, Herbert L.

    2008-01-01

    Persons crossing international boundaries away from their medical support systems are put at risk for illness and injury. Travel medicine is a new medical discipline that quantifies these health risks and develops strategies for reducing them. Obtaining health and evacuation insurance for a future trip is important for persons with medical conditions, those planning trips to developing tropical or semi-tropical regions of the world or when an international stay anywhere will be as long as a month. Pre-travel medical evaluation, vaccines against endemic infectious diseases and medications to reduce the occurrence of diarrhea and malaria during trips to endemic areas, and medications for self-treatment of common illnesses such as diarrhea are fundamental to travel medicine. There are a number of miscellaneous areas to consider in travel medicine including preventing deep vein thrombosis and minimizing jet lag during long haul air travel and reducing the occurrence of accidents and water- and altitude-related illnesses. An important recently defined challenge to the field is the growing number of ill-prepared persons put at great risk for illness while visiting friends and relatives living in areas of reduced hygiene. All persons need to have an idea of how and where they may find medical care if they develop illness while abroad. This article summarizes essential elements in travel medicine and offers 10 recommendations for safe travel. PMID:18596858

  16. Critical capacity, travel time delays and travel time distribution of rapid mass transit systems

    NASA Astrophysics Data System (ADS)

    Legara, Erika Fille; Monterola, Christopher; Lee, Kee Khoon; Hung, Gih Guang

    2014-07-01

    We set up a mechanistic agent-based model of a rapid mass transit system. Using empirical data from Singapore’s unidentifiable smart fare card, we validate our model by reconstructing actual travel demand and duration of travel statistics. We subsequently use this model to investigate two phenomena that are known to significantly affect the dynamics within the RTS: (1) overloading in trains and (2) overcrowding in the RTS platform. We demonstrate that by varying the loading capacity of trains, a tipping point emerges at which an exponential increase in the duration of travel time delays is observed. We also probe the impact on the rail system dynamics of three types of passenger growth distribution across stations: (i) Dirac delta, (ii) uniform and (iii) geometric, which is reminiscent of the effect of land use on transport. Under the assumption of a fixed loading capacity, we demonstrate the dependence of a given origin-destination (OD) pair on the flow volume of commuters in station platforms.

  17. Practice makes proficient: pigeons (Columba livia) learn efficient routes on full-circuit navigational traveling salesperson problems.

    PubMed

    Baron, Danielle M; Ramirez, Alejandro J; Bulitko, Vadim; Madan, Christopher R; Greiner, Ariel; Hurd, Peter L; Spetch, Marcia L

    2015-01-01

    Visiting multiple locations and returning to the start via the shortest route, referred to as the traveling salesman (or salesperson) problem (TSP), is a valuable skill for both humans and non-humans. In the current study, pigeons were trained with increasing set sizes of up to six goals, with each set size presented in three distinct configurations, until consistency in route selection emerged. After training at each set size, the pigeons were tested with two novel configurations. All pigeons acquired routes that were significantly more efficient (i.e., shorter in length) than expected by chance selection of the goals. On average, the pigeons also selected routes that were more efficient than expected based on a local nearest-neighbor strategy and were as efficient as the average route generated by a crossing-avoidance strategy. Analysis of the routes taken indicated that they conformed to both a nearest-neighbor and a crossing-avoidance strategy significantly more often than expected by chance. Both the time taken to visit all goals and the actual distance traveled decreased from the first to the last trials of training in each set size. On the first trial with novel configurations, average efficiency was higher than chance, but was not higher than expected from a nearest-neighbor or crossing-avoidance strategy. These results indicate that pigeons can learn to select efficient routes on a TSP problem.

  18. Optic flow informs distance but not profitability for honeybees

    PubMed Central

    Shafir, Sharoni; Barron, Andrew B.

    2010-01-01

    How do flying insects monitor foraging efficiency? Honeybees (Apis mellifera) use optic flow information as an odometer to estimate distance travelled, but here we tested whether optic flow informs estimation of foraging costs also. Bees were trained to feeders in flight tunnels such that bees experienced the greatest optic flow en route to the feeder closest to the hive. Analyses of dance communication showed that, as expected, bees indicated the close feeder as being further, but they also indicated this feeder as the more profitable, and preferentially visited this feeder when given a choice. We show that honeybee estimates of foraging cost are not reliant on optic flow information. Rather, bees can assess distance and profitability independently and signal these aspects as separate elements of their dances. The optic flow signal is sensitive to the nature of the environment travelled by the bee, and is therefore not a good index of flight energetic costs, but it provides a good indication of distance travelled for purpose of navigation and communication, as long as the dancer and recruit travel similar routes. This study suggests an adaptive dual processing system in honeybees for communicating and navigating distance flown and for evaluating its energetic costs. PMID:20018787

  19. Summer Travel: Plan Ahead To Stay Healthy

    MedlinePlus

    ... This Issue Features Summer Travel Strange Migrations and Killer Cramps Health Capsules How Secondhand Smoke Affects the ... healthy.” search Features Summer Travel Strange Migrations and Killer Cramps Wise Choices Links Plan for Healthy Travel ...

  20. Travelers' Health: Natural Disasters and Environmental Hazards

    MedlinePlus

    ... Safety Blood Clots Bug Bites Business Travel Cold Climates Counterfeit Drugs Cruise Ship Travel Families with Children ... Abroad Getting Sick After Travel High Altitudes Hot Climates Humanitarian Aid Workers Humanitarian Aid Workers in Ecuador ...

  1. 25 CFR 700.533 - Restrictions affecting travel and travel expense reimbursement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Restrictions affecting travel and travel expense... travel and travel expense reimbursement. (a) When an employee is on officially authorized travel his or... in cash or kind for travel expenses from any other source, even when the employee's expenses...

  2. 25 CFR 700.533 - Restrictions affecting travel and travel expense reimbursement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Restrictions affecting travel and travel expense... travel and travel expense reimbursement. (a) When an employee is on officially authorized travel his or... in cash or kind for travel expenses from any other source, even when the employee's expenses...

  3. 25 CFR 700.533 - Restrictions affecting travel and travel expense reimbursement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Restrictions affecting travel and travel expense... travel and travel expense reimbursement. (a) When an employee is on officially authorized travel his or... in cash or kind for travel expenses from any other source, even when the employee's expenses...

  4. 25 CFR 700.533 - Restrictions affecting travel and travel expense reimbursement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Restrictions affecting travel and travel expense... travel and travel expense reimbursement. (a) When an employee is on officially authorized travel his or... in cash or kind for travel expenses from any other source, even when the employee's expenses...

  5. 25 CFR 700.533 - Restrictions affecting travel and travel expense reimbursement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Restrictions affecting travel and travel expense... travel and travel expense reimbursement. (a) When an employee is on officially authorized travel his or... in cash or kind for travel expenses from any other source, even when the employee's expenses...

  6. New York Household Travel Patterns: A Comparison Analysis

    SciTech Connect

    Hu, Patricia S; Reuscher, Tim

    2007-05-01

    In 1969, the U. S. Department of Transportation began collecting detailed data on personal travel to address various transportation planning issues. These issues range from assessing transportation investment programs to developing new technologies to alleviate congestion. This 1969 survey was the birth of the Nationwide Personal Transportation Survey (NPTS). The survey was conducted again in 1977, 1983, 1990 and 1995. Longer-distance travel was collected in 1977 and 1995. In 2001, the survey was renamed to the National Household Travel Survey (NHTS) and collected both daily and longer-distance trips in one survey. In addition to the number of sample households that the national NPTS/NHTS survey allotted to New York State (NYS), the state procured an additional sample of households in both the 1995 and 2001 surveys. In the 1995 survey, NYS procured an addition sample of more than 9,000 households, increasing the final NY NPTS sample size to a total of 11,004 households. Again in 2001, NYS procured 12,000 additional sample households, increasing the final New York NHTS sample size to a total of 13,423 households with usable data. These additional sample households allowed NYS to address transportation planning issues pertinent to geographic areas significantly smaller than for what the national NPTS and NHTS data are intended. Specifically, these larger sample sizes enable detailed analysis of twelve individual Metropolitan Planning Organizations (MPOs). Furthermore, they allowed NYS to address trends in travel behavior over time. In this report, travel data for the entire NYS were compared to those of the rest of the country with respect to personal travel behavior and key travel determinants. The influence of New York City (NYC) data on the comparisons of the state of New York to the rest of the country was also examined. Moreover, the analysis examined the relationship between population density and travel patterns, and the similarities and differences among New

  7. Traversing psychological distance.

    PubMed

    Liberman, Nira; Trope, Yaacov

    2014-07-01

    Traversing psychological distance involves going beyond direct experience, and includes planning, perspective taking, and contemplating counterfactuals. Consistent with this view, temporal, spatial, and social distances as well as hypotheticality are associated, affect each other, and are inferred from one another. Moreover, traversing all distances involves the use of abstraction, which we define as forming a belief about the substitutability for a specific purpose of subjectively distinct objects. Indeed, across many instances of both abstraction and psychological distancing, more abstract constructs are used for more distal objects. Here, we describe the implications of this relation for prediction, choice, communication, negotiation, and self-control. We ask whether traversing distance is a general mental ability and whether distance should replace expectancy in expected-utility theories. PMID:24726527

  8. The Extragalactic Distance Scale

    NASA Astrophysics Data System (ADS)

    Livio, Mario; Donahue, Megan; Panagia, Nino

    1997-07-01

    Participants; Preface; Foreword; Early history of the distance scale problem, S. van den Bergh; Cosmology: From Hubble to HST, M. S. Turner; Age constraints nucleocosmochronology, J. Truran; The ages of globular clusters, P. Demarque; The linearity of the Hubble flow M. Postman; Gravitational lensing and the extragalactic distance scale, R. D. Blandford andT . Kundic; Using the cosmic microwave background to constrain the Hubble constant A. Lasenby and T M. Jones; Cepheids as distance indicators, N. R. Tanvir; The I-band Tully-Fisher relation and the Hubble constant, R. Giovanell; The calibration of type 1a supernovae as standard candles, A. Saha; Focusing in on the Hubble constant, G. A. Tammann & M. Federspiel; Interim report on the calibration of the Tully-Fisher relation in the HST Key Project to measure the Hubble constant, J. Mould et al.; Hubble Space Telescope Key Project on the extragalactic distance scale, W. L. Freedman, B. F. Madore and T R. C. Kennicutt; Novae as distance indicators, M. Livio; Verifying the planetary nebula luminosity function method, G. H. Jacoby; On the possible use of radio supernovae for distance determinations, K. W. Weiler et al.; Post-AGB stars as standard candles, H. Bond; Helium core flash at the tip of the red giant branch: a population II distance indicator, B. F. Madore, W. L. Freedman and T S. Sakai; Globular clusters as distance indicators, B. C. Whitmore; Detached eclipsing binaries as primary distance and age indicators, B. Paczynski; Light echoes: geometric measurement of galaxy distances, W. B. Sparks; The SBF survey of galaxy distances J. L. Tonry; Extragalactic distance scales: The long and short of it, V. Trimble.

  9. Stable operating regime for traveling wave devices

    DOEpatents

    Carlsten, Bruce E.

    2000-01-01

    Autophase stability is provided for a traveling wave device (TWD) electron beam for amplifying an RF electromagnetic wave in walls defining a waveguide for said electromagnetic wave. An off-axis electron beam is generated at a selected energy and has an energy noise inherently arising from electron gun. The off-axis electron beam is introduced into the waveguide. The off-axis electron beam is introduced into the waveguide at a second radius. The waveguide structure is designed to obtain a selected detuning of the electron beam. The off-axis electron beam has a velocity and the second radius to place the electron beam at a selected distance from the walls defining the waveguide, wherein changes in a density of the electron beam due to the RF electromagnetic wave are independent of the energy of the electron beam to provide a concomitant stable operating regime relative to the energy noise.

  10. Diffusive behavior of a greedy traveling salesman

    NASA Astrophysics Data System (ADS)

    Lipowski, Adam; Lipowska, Dorota

    2011-06-01

    Using Monte Carlo simulations we examine the diffusive properties of the greedy algorithm in the d-dimensional traveling salesman problem. Our results show that for d=3 and 4 the average squared distance from the origin is proportional to the number of steps t. In the d=2 case such a scaling is modified with some logarithmic corrections, which might suggest that d=2 is the critical dimension of the problem. The distribution of lengths also shows marked differences between d=2 and d>2 versions. A simple strategy adopted by the salesman might resemble strategies chosen by some foraging and hunting animals, for which anomalous diffusive behavior has recently been reported and interpreted in terms of Lévy flights. Our results suggest that broad and Lévy-like distributions in such systems might appear due to dimension-dependent properties of a search space.

  11. 41 CFR 301-31.11 - May my agency pay me a per diem allowance instead of actual expenses?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false May my agency pay me a per diem allowance instead of actual expenses? 301-31.11 Section 301-31.11 Public Contracts and... TRAVEL EXPENSES 31-THREATENED LAW ENFORCEMENT/INVESTIGATIVE EMPLOYEES § 301-31.11 May my agency pay me...

  12. 41 CFR 302-9.103 - Do I have to ship my POV to my actual post of duty?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false Do I have to ship my POV to my actual post of duty? 302-9.103 Section 302-9.103 Public Contracts and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES TRANSPORTATION AND STORAGE OF PROPERTY...

  13. Self-Actualization, Liberalism, and Humanistic Education.

    ERIC Educational Resources Information Center

    Porter, Charles Mack

    1979-01-01

    The relationship between personality factors and political orientation has long been of interest to psychologists. This study tests the hypothesis that there is no significant relationship between self-actualization and liberalism-conservatism. The hypothesis is supported. (Author)

  14. Air Travel Considerations for the Patients With Heart Failure

    PubMed Central

    Izadi, Morteza; Alemzadeh-Ansari, Mohammad Javad; Kazemisaleh, Davood; Moshkani-Farahani, Maryam

    2014-01-01

    Context: Prevalence of patients with heart failure (HF) is increasing in worldwide, and also the number of people with HF traveling long distances is increasing. These patients are more prone to experience problems contributed air travel and needs more attention during flight. However, observational studies about problems of HF patients during flight and appropriated considerations for them are limited. Evidence Acquisition: We evaluated the conditions that may be encountered in a HF patient and provide the recommendations to prevent the exacerbation of cardiac failure during air travel. For this review article, a comprehensive search was undertaken for the studies that evaluated the complications and considerations of HF patients during flight. Data bases searched were: MEDLINE, EMBASE, Science Direct, and Google Scholar. Results: HF patients are more prone to experience respiratory distress, anxiety, stress, cardiac decompensation, and venous thromboembolism (VTE) during air travel. Although stable HF patients can tolerate air travel, but those with acute heart failure syndrome should not fly until complete improvement is achieved. Conclusions: Thus, identifying the HF patients before the flight and providing them proper education about the events that may occur during flight is necessary. PMID:25068047

  15. The scaling laws of human travel - A message from George

    NASA Astrophysics Data System (ADS)

    Brockmann, Dirk

    2006-03-01

    In the light of increasing international trade, intensified human mobility and an imminent influenza A epidemic the knowledge of dynamical and statistical properties of human travel is of fundamental importance. Despite its crucial role, a quantitative assessment of these properties on geographical scales remains elusive and the assumption that humans disperse diffusively still prevails in models. I will report on a solid and quantitative assessment of human travelling statistics by analysing the circulation of bank notes in the United States. Based on a comprehensive dataset of over a million individual displacements we find that dispersal is anomalous in two ways. First, the distribution of travelling distances decays as a power law, indicating that trajectories of bank notes are reminiscent of scale free random walks known as L'evy flights. Secondly, the probability of remaining in a small, spatially confined region for a time T is dominated by algebraic tails which attenuate the superdiffusive spread. We show that human travel can be described mathematically on many spatiotemporal scales by a two parameter continuous time random walk model to a surprising accuracy and conclude that human travel on geographical scales is an ambivalent effectively superdiffusive process.

  16. Travelers' Health: Viral Hemorrhagic Fevers

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... Guerrant RL, Walker DH, Weller PF, editors. Tropical Infectious Diseases: Principles, Pathogens and Practice. 3rd ed. Philadelphia: Elsevier; ...

  17. Influenza Prevention: Information for Travelers

    MedlinePlus

    ... season and are traveling to parts of the world where influenza activity is ongoing should get a ... have been circulating in other parts of the world. People should get vaccinated at least 2 weeks ...

  18. Travelers' Health: Injuries and Safety

    MedlinePlus

    ... optimal care for serious injuries are uncommon outside urban areas in many foreign destinations. Travelers should be ... poor in many countries, victims of injuries and violence can die before reaching a hospital, and there ...

  19. Before Departure: Advising Tropical Travellers

    PubMed Central

    Russell, Margaret

    1990-01-01

    Advising travellers to tropical and subtropical countries before their departure requires physician use of regularly updated information sources. The author outlines an approach to risk assessment and presents an overview of important issues and some information sources. PMID:21233911

  20. Tuberculosis Information for International Travelers

    MedlinePlus

    ... shelters). Travelers who will be working in clinics, hospitals, or other health care settings where TB patients are likely to be encountered should consult infection control or occupational health experts. They should ask about ...

  1. A pilot study using global positioning systems (GPS) devices and surveys to ascertain older adults' travel patterns.

    PubMed

    Yen, Irene H; Leung, Cindy W; Lan, Mars; Sarrafzadeh, Majid; Kayekjian, Karen C; Duru, O Kenrik

    2015-04-01

    Some studies indicate that older adults lead active lives and travel to many destinations including those not in their immediate residential neighborhoods. We used global positioning system (GPS) devices to track the travel patterns of 40 older adults (mean age: 69) in San Francisco and Los Angeles. Study participants wore the GPS devices for 7 days in fall 2010 and winter 2011. We collected survey responses concurrently about travel patterns. GPS data showed a mean of four trips/day, and a mean trip distance of 7.6 km. Survey data indicated that older adults commonly made trips for four activities (e.g., volunteering, work, visiting friends) at least once each week. Older adults regularly travel outside their residential neighborhoods. GPS can document the mode of travel, the path of travel, and the destinations. Surveys can document the purpose of the travel and the impressions or experiences in the specific locations.

  2. Sequentially pulsed traveling wave accelerator

    DOEpatents

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  3. [Sexually transmitted diseases and travel].

    PubMed

    Halioua, B; Prazuck, T; Malkin, J E

    1997-01-01

    Travelers are highly exposed to acquiring sexually transmitted diseases especially since the most popular destinations are high risk areas. While this risk applies to all travelers, it is highest for the "sex" tourist who is typically a male with a mean age of 38 years. Awareness of risks is still incomplete, especially with regard to HIV. Several studies have shown that only 20% to 70% of travelers use condoms. This finding accounts for the high incidence of sexually transmitted diseases in returning travelers: 2% to 10%. The risk of HIV infection is particularly high for persons living abroad. Based on available data, we can define the typical profile of the high risk traveler who should be targeted for prevention. Prevention depends on providing adequate information before departure, especially concerning HIV infection. Use of a condom throughout sexual contact is a basic safety rule. However condom quality is poor in many developing countries. Returning travelers should seek medical advice if manifestations involving the anogenital regions should appear. PMID:9612761

  4. [Sexually transmitted diseases and travel].

    PubMed

    Halioua, B; Prazuck, T; Malkin, J E

    1997-01-01

    Travelers are highly exposed to acquiring sexually transmitted diseases especially since the most popular destinations are high risk areas. While this risk applies to all travelers, it is highest for the "sex" tourist who is typically a male with a mean age of 38 years. Awareness of risks is still incomplete, especially with regard to HIV. Several studies have shown that only 20% to 70% of travelers use condoms. This finding accounts for the high incidence of sexually transmitted diseases in returning travelers: 2% to 10%. The risk of HIV infection is particularly high for persons living abroad. Based on available data, we can define the typical profile of the high risk traveler who should be targeted for prevention. Prevention depends on providing adequate information before departure, especially concerning HIV infection. Use of a condom throughout sexual contact is a basic safety rule. However condom quality is poor in many developing countries. Returning travelers should seek medical advice if manifestations involving the anogenital regions should appear.

  5. An estimation of Canadian population exposure to cosmic rays from air travel.

    PubMed

    Chen, Jing; Newton, Dustin

    2013-03-01

    Based on air travel statistics in 1984, it was estimated that less than 4 % of the population dose from cosmic ray exposure would result from air travel. In the present study, cosmic ray doses were calculated for more than 3,000 flights departing from more than 200 Canadian airports using actual flight profiles. Based on currently available air travel statistics, the annual per capita effective dose from air transportation is estimated to be 32 μSv for Canadians, about 10 % of the average cosmic ray dose received at ground level (310 μSv per year).

  6. Distance Learning. PEPNet Tipsheet

    ERIC Educational Resources Information Center

    Keefe, Barbara, Comp.

    2002-01-01

    Distance learning is the separation of teacher and student by time and space. Rapid advances in communications technology have allowed distance learning to become one of the fastest-growing trends in higher education. College courses are being delivered across a highway that is global in scope. Today, two thirds of the 4,000 accredited colleges…

  7. Is Distance Learning Transformational?

    ERIC Educational Resources Information Center

    Hoskins, Barbara J.

    2013-01-01

    Is distance learning transformational? The author heard this question posed to a panel of faculty members during Distance Education Week activities. After reflecting upon her own students' reaction to her syllabus, her answer to the question changed from an initial, enthusiastic "yes" to a reflective "maybe," given the most favorable environment.…

  8. Education at a Distance.

    ERIC Educational Resources Information Center

    Maffett, Sheryl Price

    2007-01-01

    Distance learning has been around since the old "course in a box" correspondence classes, but with the advent of sophisticated online course management systems, learning at a distance is contributing to a major paradigm shift in higher education. That shift includes applying corporate concepts to education--students, for example, are "consumers,"…

  9. Biomechanics of Distance Running.

    ERIC Educational Resources Information Center

    Cavanagh, Peter R., Ed.

    Contributions from researchers in the field of running mechanics are included in the 13 chapters of this book. The following topics are covered: (1) "The Mechanics of Distance Running: A Historical Perspective" (Peter Cavanagh); (2) "Stride Length in Distance Running: Velocity, Body Dimensions, and Added Mass Effects" (Peter Cavanagh, Rodger…

  10. Mentoring Distance Learners.

    ERIC Educational Resources Information Center

    Zeeb, Patricia

    2000-01-01

    Defines mentoring, focusing on its use in distance education. Outlines categories of mentoring--traditional, peer, group or team, and online or virtual (telementoring). Discusses mentoring and technological change types of mentors in distance education classes; the role of computer-mediated communications; and decreasing attrition by pairing…

  11. Delivering distance training to rural health care professionals.

    PubMed

    Li, Jie; Runderson, Robert A; Burnham, Judy F; Staggs, Geneva Bush; Robertson, Justin C; Williams, Thomas L

    2005-01-01

    This article reports on a project that delivers distance training to rural health care professionals. Traveling to provide training on information-seeking skills to rural health professionals is time consuming and costly. In addition to face-to-face training, the University of South Alabama Biomedical Library's SAMNet project seeks to deliver multimedia training to rural health care professionals. The project uses information technology to package training courses combining PowerPoint slides and video instructions. This article describes the rationale, training module design and development, and the information technology and software used in the project. Multimedia packaged distance training courses provide a practical alternative to on-site training for rural health care professionals. It enables librarians to provide training without traveling long distance, thus saving time and money. Additionally, rural health care professionals may access the modules at a time convenient to them and proceed at a pace suitable to their learning style. PMID:15760832

  12. Why do medical tourists travel to where they do? The role of networks in determining medical travel.

    PubMed

    Hanefeld, J; Lunt, N; Smith, R; Horsfall, D

    2015-01-01

    Evidence on medical tourism, including patient motivation, is increasing. Existing studies have focused on identifying push and pull factors across different types of treatment, for example cosmetic or bariatric surgery, or on groups, such as diaspora patients returning 'home' for treatment. Less attention has been on why individuals travel to specific locations or providers and on how this decision is made. The paper focused on the role of networks, defined as linkages - formal and informal - between individual providers, patients and facilitators to explain why and where patients travel. Findings are based on a recently completed, two year research project, which examined the effects of medical tourism on the UK NHS. Research included in-depth interviews with 77 returning medical tourists and over sixty managers, medical travel facilitators, clinicians and providers of medical tourism in recipient countries to understand the medical tourism industry. Interviews were conducted between 2011 and 2012, recorded and transcribed, or documented through note taking. Authors undertook a thematic analysis of interviews to identify treatment pathways by patients, and professional linkages between clinicians and facilitators to understand choice of treatment destination. The results highlight that across a large sample of patients travelling for a variety of conditions from dental treatment, cosmetic and bariatric surgery, through to specialist care the role of networks is critical to understand choice of treatment, provider and destination. While distance, costs, expertise and availability of treatment all were factors influencing patients' decision to travel, choice of destination and provider was largely the result of informal networks, including web fora, personal recommendations and support groups. Where patients were referred by UK clinicians or facilitators these followed informal networks. In conclusion, investigating medical travel through focus on networks of

  13. Why do medical tourists travel to where they do? The role of networks in determining medical travel.

    PubMed

    Hanefeld, J; Lunt, N; Smith, R; Horsfall, D

    2015-01-01

    Evidence on medical tourism, including patient motivation, is increasing. Existing studies have focused on identifying push and pull factors across different types of treatment, for example cosmetic or bariatric surgery, or on groups, such as diaspora patients returning 'home' for treatment. Less attention has been on why individuals travel to specific locations or providers and on how this decision is made. The paper focused on the role of networks, defined as linkages - formal and informal - between individual providers, patients and facilitators to explain why and where patients travel. Findings are based on a recently completed, two year research project, which examined the effects of medical tourism on the UK NHS. Research included in-depth interviews with 77 returning medical tourists and over sixty managers, medical travel facilitators, clinicians and providers of medical tourism in recipient countries to understand the medical tourism industry. Interviews were conducted between 2011 and 2012, recorded and transcribed, or documented through note taking. Authors undertook a thematic analysis of interviews to identify treatment pathways by patients, and professional linkages between clinicians and facilitators to understand choice of treatment destination. The results highlight that across a large sample of patients travelling for a variety of conditions from dental treatment, cosmetic and bariatric surgery, through to specialist care the role of networks is critical to understand choice of treatment, provider and destination. While distance, costs, expertise and availability of treatment all were factors influencing patients' decision to travel, choice of destination and provider was largely the result of informal networks, including web fora, personal recommendations and support groups. Where patients were referred by UK clinicians or facilitators these followed informal networks. In conclusion, investigating medical travel through focus on networks of

  14. Comparison of geographic methods to assess travel patterns of persons diagnosed with HIV in Philadelphia: how close is close enough?

    PubMed

    Eberhart, Michael G; Share, Amanda M; Shpaner, Mark; Brady, Kathleen A

    2015-02-01

    Travel distance to medical care has been assessed using a variety of geographic methods. Network analyses are less common, but may generate more accurate estimates of travel costs. We compared straight-line distances and driving distance, as well as average drive time and travel time on a public transit network for 1789 persons diagnosed with HIV between 2010 and 2012 to identify differences overall, and by distinct geographic areas of Philadelphia. Paired t-tests were used to assess differences across methods, and analysis of variance was used to assess between-group differences. Driving distances were significantly longer than straight-line distances (p<0.001) and transit times were significantly longer than driving times (p<0.001). Persons living in the northeast section of the city traveled greater distances, and at greater cost of time and effort, than persons in all other areas of the city (p<0.001). Persons living in the northwest section of the city traveled farther and longer than all other areas except the northeast (p<0.0001). Network analyses that include public transit will likely produce a more realistic estimate of the travel costs, and may improve models to predict medical care outcomes.

  15. Is Distance to Provider a Barrier to Care for Medicaid Patients with Breast, Colorectal, or Lung Cancer?

    ERIC Educational Resources Information Center

    Scoggins, John F.; Fedorenko, Catherine R.; Donahue, Sara M. A.; Buchwald, Dedra; Blough, David K.; Ramsey, Scott D.

    2012-01-01

    Purpose: Distance to provider might be an important barrier to timely diagnosis and treatment for cancer patients who qualify for Medicaid coverage. Whether driving time or driving distance is a better indicator of travel burden is also of interest. Methods: Driving distances and times from patient residence to primary care provider were…

  16. Characterizing International Travel Behavior from Geotagged Photos: A Case Study of Flickr.

    PubMed

    Yuan, Yihong; Medel, Monica

    2016-01-01

    Recent advances in multimedia and mobile technologies have facilitated large volumes of travel photos to be created and shared online. Although previous studies have utilized geotagged photos to model travel patterns at individual locations, there is limited research on how these datasets can model international travel behavior and inter-country travel flows-a crucial indicator to quantify the interactions between countries in tourism economics. Realizing the necessity to investigate the potential of geotagged photos in tourism geography, this research investigates international travel patterns from two perspectives: 1) We apply a series of indicators (radius of gyration (ROG), number of countries visited, and entropy) to measure the descriptive characteristics of international travel in different countries; 2) By constructing a gravity model of trade, we investigate how distance decay influences the magnitude of international travel flow between geographic entities, and whether (or how much) the popularity of a given destination (defined as the percentage of tourist income in national gross domestic product (GDP)) affects travel choices in different countries. The results provide valuable input to various commercial applications such as individual travel planning and destination suggestions.

  17. Characterizing International Travel Behavior from Geotagged Photos: A Case Study of Flickr.

    PubMed

    Yuan, Yihong; Medel, Monica

    2016-01-01

    Recent advances in multimedia and mobile technologies have facilitated large volumes of travel photos to be created and shared online. Although previous studies have utilized geotagged photos to model travel patterns at individual locations, there is limited research on how these datasets can model international travel behavior and inter-country travel flows-a crucial indicator to quantify the interactions between countries in tourism economics. Realizing the necessity to investigate the potential of geotagged photos in tourism geography, this research investigates international travel patterns from two perspectives: 1) We apply a series of indicators (radius of gyration (ROG), number of countries visited, and entropy) to measure the descriptive characteristics of international travel in different countries; 2) By constructing a gravity model of trade, we investigate how distance decay influences the magnitude of international travel flow between geographic entities, and whether (or how much) the popularity of a given destination (defined as the percentage of tourist income in national gross domestic product (GDP)) affects travel choices in different countries. The results provide valuable input to various commercial applications such as individual travel planning and destination suggestions. PMID:27159195

  18. Characterizing International Travel Behavior from Geotagged Photos: A Case Study of Flickr

    PubMed Central

    Yuan, Yihong; Medel, Monica

    2016-01-01

    Recent advances in multimedia and mobile technologies have facilitated large volumes of travel photos to be created and shared online. Although previous studies have utilized geotagged photos to model travel patterns at individual locations, there is limited research on how these datasets can model international travel behavior and inter-country travel flows—a crucial indicator to quantify the interactions between countries in tourism economics. Realizing the necessity to investigate the potential of geotagged photos in tourism geography, this research investigates international travel patterns from two perspectives: 1) We apply a series of indicators (radius of gyration (ROG), number of countries visited, and entropy) to measure the descriptive characteristics of international travel in different countries; 2) By constructing a gravity model of trade, we investigate how distance decay influences the magnitude of international travel flow between geographic entities, and whether (or how much) the popularity of a given destination (defined as the percentage of tourist income in national gross domestic product (GDP)) affects travel choices in different countries. The results provide valuable input to various commercial applications such as individual travel planning and destination suggestions. PMID:27159195

  19. 8 CFR 1244.15 - Travel abroad.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Travel abroad. 1244.15 Section 1244.15... REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.15 Travel abroad. (a) After... Status shall not constitute permission to travel abroad. Permission to travel may be granted by...

  20. 8 CFR 244.15 - Travel abroad.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Travel abroad. 244.15 Section 244.15 Aliens... NATIONALS OF DESIGNATED STATES § 244.15 Travel abroad. (a) After the grant of Temporary Protected Status... to travel abroad. Permission to travel may be granted by the director pursuant to the...

  1. 8 CFR 244.15 - Travel abroad.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Travel abroad. 244.15 Section 244.15 Aliens... NATIONALS OF DESIGNATED STATES § 244.15 Travel abroad. (a) After the grant of Temporary Protected Status... to travel abroad. Permission to travel may be granted by the director pursuant to the...

  2. 8 CFR 1244.15 - Travel abroad.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Travel abroad. 1244.15 Section 1244.15... REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.15 Travel abroad. (a) After... Status shall not constitute permission to travel abroad. Permission to travel may be granted by...

  3. 38 CFR 21.7103 - Travel expenses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Travel expenses. 21.7103... Bill-Active Duty) Counseling § 21.7103 Travel expenses. (a) Travel for veterans and servicemembers. (1... travel to and from the place of counseling for individuals who are required to receive counseling if—...

  4. 28 CFR 2.93 - Travel approval.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Travel approval. 2.93 Section 2.93... Travel approval. (a) A parolee's Supervision Officer may approve travel outside the district of... possibilities. (3) Recurring travel across a district boundary, not to exceed fifty miles outside the...

  5. 28 CFR 2.93 - Travel approval.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Travel approval. 2.93 Section 2.93... Travel approval. (a) A parolee's Supervision Officer may approve travel outside the district of... possibilities. (3) Recurring travel across a district boundary, not to exceed fifty miles outside the...

  6. Development of a distance-to-roadway proximity metric to compare near-road pollutant levels to a central site monitor

    NASA Astrophysics Data System (ADS)

    Barzyk, Timothy M.; George, Barbara Jane; Vette, Alan F.; Williams, Ronald W.; Croghan, Carry W.; Stevens, Carvin D.

    The primary objective of the Detroit Exposure and Aerosol Research Study (DEARS) was to compare air pollutant concentrations measured at various neighborhoods, or exposure monitoring areas (EMAs), throughout a major metropolitan area to levels measured at a central site or community monitor. One of the EMAs was located near a busy freeway (annual average daily traffic (AADT) of ˜130,000) so that impacts of mobile sources could be examined. Air pollution concentrations from the roadway-proximate sites were compared to the central site monitor. The volatile organic compounds (VOCs) selected (benzene, toluene, ethylbenzene, m,p- and o-xylene, 1,3 butadiene, 1,3,5-trimethylbenzene and 4-ethyltoluene) are typically associated with mobile sources. Gradients were also evident that demonstrated the amplification of pollutant levels near the roadway compared to the community monitor. A novel distance-to-roadway proximity metric was developed to plot the measurements and model these gradients. Effective distance represents the actual distance an air parcel travels from the middle of a roadway to a site and varies as a function of wind direction, whereas perpendicular distance is a fixed distance oriented normal to the roadway. Perpendicular distance is often used as a proxy for exposures to traffic emissions in epidemiological studies. Elevated concentrations of all the compounds were found for both a summer and winter season. Effective distance was found to be a statistically significant ( p < 0.05) univariate predictor for concentrations of toluene, ethylbenzene, m,p-xylene and o-xylene for summer 2005. For each of these pollutants, effective distance yielded lower p-values than the corresponding perpendicular distance models, and model fit improved. Results demonstrate that this near-road EMA had elevated levels of traffic-related VOCs compared to the community monitor, and that effective distance was a more accurate predictor of the degree to which they were elevated as

  7. Estimating Distances from Parallaxes

    NASA Astrophysics Data System (ADS)

    Bailer-Jones, Coryn A. L.

    2015-10-01

    Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that doing this is not trivial once the fractional parallax error is larger than about 20%, which will be the case for about 80% of stars in the Gaia catalog. Estimating distances is an inference problem in which the use of prior assumptions is unavoidable. I investigate the properties and performance of various priors and examine their implications. A supposed uninformative uniform prior in distance is shown to give very poor distance estimates (large bias and variance). Any prior with a sharp cut-off at some distance has similar problems. The choice of prior depends on the information one has available—and is willing to use—concerning, e.g., the survey and the Galaxy. I demonstrate that a simple prior which decreases asymptotically to zero at infinite distance has good performance, accommodates nonpositive parallaxes, and does not require a bias correction.

  8. Tropical Skin Infections Among Israeli Travelers

    PubMed Central

    Solomon, Michal; Benenson, Shmuel; Baum, Sharon; Schwartz, Eli

    2011-01-01

    Infectious skin disorders are common dermatologic illnesses in travelers. Knowledge of post-travel–related infectious skin disorders will allow for effective pre- and post-travel counseling. All cases of returning travelers seen in our center seeking care for infectious skin diseases were included in this study. For a comparison, data on returned travelers with non-infectious skin diseases and healthy travelers who had pre-travel consultations in our institution were also analyzed. Altogether, skin-related diagnosis was reported in 540 ill travelers, and among them, 286 (53%) had infectious skin diseases. Tropical skin infection was diagnosed in 64% of the infectious cases. Travelers returning from Latin America were significantly more ill with tropical skin infections than those traveling to Asia and Africa, The most common diagnoses were cutaneous leishmaniasis, myiasis, and cutaneous larva migrans. In conclusion, tropical skin infections are common among Israeli travelers, especially among those who visited Latin America. PMID:22049040

  9. Rapid retraction of microvolume aqueous plugs traveling in a wettable capillary

    NASA Astrophysics Data System (ADS)

    Kim, Jinho; O'Neill, John D.; Vunjak-Novakovic, Gordana

    2015-10-01

    We report a transport behavior—specifically, rapid retraction movement—of small (˜μL) deionized water plugs traveling in series within a small wettable tubular geometry. In this study, two water plugs separated by a certain distance in a dry cylindrical glass capillary were moved by positive pressure airflow applied at the tube inlet. As the plugs travel, a thin aqueous film is generated between the plugs as a result of the leading plug's aqueous deposition onto the inner surface of the tube. The leading plug continuously loses volume by film deposition onto the surface and eventually ruptures. Then, the lagging plug quickly travels the distance initially separating the two plugs (plug retraction). Our studies show that the rapid retraction of the lagging plug is caused by surface tension in addition to the positive pressure applied. Furthermore, the plug retraction speed is strongly affected by tube radius and the distance between the plugs.

  10. The Relationship Between Distance to Water Source and Moderate-to-Severe Diarrhea in the Global Enterics Multi-Center Study in Kenya, 2008-2011.

    PubMed

    Nygren, Benjamin L; O'Reilly, Ciara E; Rajasingham, Anangu; Omore, Richard; Ombok, Maurice; Awuor, Alex O; Jaron, Peter; Moke, Fenny; Vulule, John; Laserson, Kayla; Farag, Tamer H; Nasrin, Dilruba; Nataro, James P; Kotloff, Karen L; Levine, Myron M; Derado, Gordana; Ayers, Tracy L; Lash, R Ryan; Breiman, Robert F; Mintz, Eric D

    2016-05-01

    In the developing world, fetching water for drinking and other household uses is a substantial burden that affects water quantity and quality in the household. We used logistic regression to examine whether reported household water fetching times were a risk factor for moderate-to-severe diarrhea (MSD) using case-control data of 3,359 households from the Global Enterics Multi-Center Study in Kenya in 2009-2011. We collected additional global positioning system (GPS) data for a subset of 254 randomly selected households and compared GPS-based straight line and actual travel path distances to fetching times reported by respondents. GPS-based data were highly correlated with respondent-provided times (Spearman correlation coefficient = 0.81, P < 0.0001). The median estimated one-way distance to water source was 200 m for cases and 171 for controls (Wilcoxon rank sums/Mann-Whitney P = 0.21). A round-trip fetching time of > 30 minutes was reported by 25% of cases versus 15% of controls and was significantly associated with MSD where rainwater was not used in the last 2 weeks (odds ratio = 1.97, 95% confidence interval = 1.56-2.49). These data support the United Nations definition of access to an improved water source being within 30 minutes total round-trip travel time. PMID:26928833

  11. The Relationship Between Distance to Water Source and Moderate-to-Severe Diarrhea in the Global Enterics Multi-Center Study in Kenya, 2008-2011.

    PubMed

    Nygren, Benjamin L; O'Reilly, Ciara E; Rajasingham, Anangu; Omore, Richard; Ombok, Maurice; Awuor, Alex O; Jaron, Peter; Moke, Fenny; Vulule, John; Laserson, Kayla; Farag, Tamer H; Nasrin, Dilruba; Nataro, James P; Kotloff, Karen L; Levine, Myron M; Derado, Gordana; Ayers, Tracy L; Lash, R Ryan; Breiman, Robert F; Mintz, Eric D

    2016-05-01

    In the developing world, fetching water for drinking and other household uses is a substantial burden that affects water quantity and quality in the household. We used logistic regression to examine whether reported household water fetching times were a risk factor for moderate-to-severe diarrhea (MSD) using case-control data of 3,359 households from the Global Enterics Multi-Center Study in Kenya in 2009-2011. We collected additional global positioning system (GPS) data for a subset of 254 randomly selected households and compared GPS-based straight line and actual travel path distances to fetching times reported by respondents. GPS-based data were highly correlated with respondent-provided times (Spearman correlation coefficient = 0.81, P < 0.0001). The median estimated one-way distance to water source was 200 m for cases and 171 for controls (Wilcoxon rank sums/Mann-Whitney P = 0.21). A round-trip fetching time of > 30 minutes was reported by 25% of cases versus 15% of controls and was significantly associated with MSD where rainwater was not used in the last 2 weeks (odds ratio = 1.97, 95% confidence interval = 1.56-2.49). These data support the United Nations definition of access to an improved water source being within 30 minutes total round-trip travel time.

  12. Regional Travel-Time Predictions, Uncertainty and Location Improvement

    SciTech Connect

    Flanagan, M; Myers, S

    2004-07-15

    We investigate our ability to improve regional travel-time prediction and seismic event location using an a priori three-dimensional (3D) velocity model of Western Eurasia and North Africa (WENA 1.0). Three principal results are presented. First, the 3D WENA 1.0 velocity model improves travel-time prediction over the IASPI91 model, as measured by variance reduction, for regional phases recorded at 22 stations throughout the modeled region, including aseismic areas. Second, a distance-dependent uncertainty model is developed and tested for the WENA 1.0 model. Third, relocation using WENA 1.0 and the associated uncertainty model provides an end-to-end validation test. Model validation is based on a comparison of approximately 10,000 Pg, Pn, and P travel-time predictions and empirical observations from ground truth (GT) events. Ray coverage for the validation dataset provides representative, regional-distances sampling across Eurasia and North Africa. The WENA 1.0 model markedly improves travel-time predictions for most stations with an average variance reduction of 14% for all ray paths. We find that improvement is station dependent, with some stations benefiting greatly from WENA predictions (25% at OBN, and 16% at BKR), some stations showing moderate improvement (12% at ARU, and 17% at NIL), and some stations benefiting only slightly (7% at AAE, and 8% at TOL). We further test WENA 1.0 by relocating five calibration events. Again, relocation of these events is dependent on ray paths that evenly sample WENA 1.0 and therefore provide an unbiased assessment of location performance. These results highlight the importance of accurate GT datasets in assessing regional travel-time models and demonstrate that an a priori 3D model can markedly improve our ability to locate small magnitude events in a regional monitoring context.

  13. Observational Study of Travelers' Diarrhea.

    PubMed

    Meuris

    1995-03-01

    Background: European air travelers returning from Algeria, Egypt, Mexico, Morocco, and Tunisia were interviewed about their experience of travelers' diseases upon arrival in Brussels. Diarrhea was mentioned by 37% of the adults and 27% of the children. These subjects were questioned about the types of measures taken, type and duration of drug treatment (if any), and about duration of diarrhea and side effects experienced. Methods: Final analysis was performed based on 2160 interviews. The largest proportion of diarrhea was reported in the age group 15-24 years (46%). Results: The majority of the 2160 subjects had opted for drug treatment (81%): 927 subjects for loperamide alone, 235 for loperamide in combination with nifuroxazide, and 178 for nifuroxazide alone. Other drugs had been used less frequently. The median time to recovery was 2.4 days with loperamide compared to 3.2 days with nifuroxazide and to 3.4 days for the no-treatment group. Conclusions: A stratification of the results by severity of the diarrhea suggests a rank of antidiarrheal potency as follows: loperamide > nifuroxazide > no-drug treatment. The side effect with the highest incidence was constipation (2.4% with loperamide). (J Travel Med 2:11-15, 1995) Travelers' diarrhea is usually defined as the passage of at least three unformed stools per day or any number of such stools when accompanied by fever, abdominal cramping, or vomiting. The definition may be broadened to include more trivial bowel disturbance.1,2 The duration of this self-limited disease generally is 3 to 5 days. Medical intervention aims at shortening the duration of disease, thus allowing the sufferer to resume his or her usual activities at an early stage. A shortened period of recovery to physical well-being has obvious favorable economic implications if the traveler is on business and may help the maintenance of a desired level of quality of life while a traveler is on holiday. An observational study of various medical

  14. Travel patterns during pregnancy: comparison between Global Positioning System (GPS) tracking and questionnaire data

    PubMed Central

    2013-01-01

    Background Maternal exposures to traffic-related air pollution have been associated with adverse pregnancy outcomes. Exposures to traffic-related air pollutants are strongly influenced by time spent near traffic. However, little is known about women’s travel activities during pregnancy and whether questionnaire-based data can provide reliable information on travel patterns during pregnancy. Objectives Examine women’s in-vehicle travel behavior during pregnancy and examine the difference in travel data collected by questionnaire and global positioning system (GPS) and their potential for exposure error. Methods We measured work-related travel patterns in 56 pregnant women using a questionnaire and one-week GPS tracking three times during pregnancy (<20 weeks, 20–30 weeks, and >30 weeks of gestation). We compared self-reported activities with GPS-derived trip distance and duration, and examined potentially influential factors that may contribute to differences. We also described in-vehicle travel behavior by pregnancy periods and influences of demographic and personal factors on daily travel times. Finally, we estimated personal exposure to particle-bound polycyclic aromatic hydrocarbon (PB-PAH) and examined the magnitude of exposure misclassification using self-reported vs. GPS travel data. Results Subjects overestimated both trip duration and trip distance compared to the GPS data. We observed moderately high correlations between self-reported and GPS-recorded travel distance (home to work trips: r = 0.88; work to home trips: r = 0.80). Better agreement was observed between the GPS and the self-reported travel time for home to work trips (r = 0.77) than work to home trips (r = 0.64). The subjects on average spent 69 and 93 minutes traveling in vehicles daily based on the GPS and self-reported data, respectively. Longer daily travel time was observed among participants in early pregnancy, and during certain pregnancy periods in women with

  15. 76 FR 43236 - Federal Travel Regulation (FTR): Temporary Duty (TDY) Travel Allowances: Notice of Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ... ADMINISTRATION 41 CFR Chapter 301 Federal Travel Regulation (FTR): Temporary Duty (TDY) Travel Allowances: Notice of Public Meeting AGENCY: Office of Governmentwide Policy, General Services Administration (GSA... Federal Travel Regulation (FTR) in an effort to streamline travel policies, increase travel efficiency...

  16. Relative Proximity Theory: Measuring the Gap between Actual and Ideal Online Course Delivery

    ERIC Educational Resources Information Center

    Swart, William; MacLeod, Kenneth; Paul, Ravi; Zhang, Aixiu; Gagulic, Mario

    2014-01-01

    Based on the Theory of Transactional Distance and Needs Assessment, this article reports a procedure for quantitatively measuring how close the actual delivery of a course was to ideal, as perceived by students. It extends Zhang's instrument and prescribes the computational steps to calculate relative proximity at the element and construct…

  17. Poliomyelitis--prevention in travellers.

    PubMed

    Mayer, Cora A; Neilson, Amy A

    2010-03-01

    This article is the second in a series providing a summary of prevention strategies and vaccination for infections that may be acquired by travellers. The series aims to provide practical strategies to assist general practitioners in giving travel advice, as a synthesis of multiple information sources which must otherwise be consulted. Poliomyelitis is a potentially fatal viral illness, which may cause acute flaccid paralysis and permanent central nervous system damage. Ongoing global efforts to eradicate poliomyelitis have been under way since 1988. Travellers are at risk of infection in countries with endemic wild poliomyelitis virus or imported cases, and can spread the infection to areas where poliomyelitis has been eradicated. While all adults should be immune to poliomyelitis, it is important that at-risk travellers are vaccinated appropriately. Vaccine options and regions currently reporting poliomyelitis are presented from a number of sources, which may facilitate the process of giving travel advice in a general practice setting, although it is also important to seek up-to-date epidemiological information.

  18. Realizing actual feedback control of complex network

    NASA Astrophysics Data System (ADS)

    Tu, Chengyi; Cheng, Yuhua

    2014-06-01

    In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.

  19. Future Trends in Business Travel Decision Making

    NASA Technical Reports Server (NTRS)

    Mason, Keith J.

    2002-01-01

    This research surveys twenty large companies and their travellers to identify and evaluate the effects of pressures on the business travel market in the future. The influence of the following areas on the decision making process are addressed: (1) Corporate travel policies and increasing professionalism in corporate purchasing; (2) The development of global strategic airline alliances; (3) The emergence of low cost airlines on short haul markets; and (4) The development of internet based booking tools and travel agency IT. The survey shows differences in views between travel managers, and travellers with regard to corporate travel policies. While travel managers see policy rules, travellers interpret these as guidelines, indicating travel managers will need to take further actions to exercise true control of travel budgets. The data shows that companies are more likely to prescribe a class of airline ticket, than the choice of airline itself. Corporate hierarchical bias in travel policies is still common both for short and particularly long haul flying. Other findings show that while travel managers believe that their companies are likely to sign global deals with strategic airline groups within a five year period in a bid to consolidating spending, they also believe that nearly a third of short haul flying will be taken with low cost carriers, indicating further penetration in this business travel market by these carriers. The paper also provides other predictions about the business travel market, based on the survey findings.

  20. Distance learning perspectives.

    PubMed

    Pandza, Haris; Masic, Izet

    2013-01-01

    The development of modern technology and the Internet has enabled the explosive growth of distance learning. distance learning is a process that is increasingly present in the world. This is the field of education focused on educating students who are not physically present in the traditional classrooms or student's campus. described as a process where the source of information is separated from the students in space and time. If there are situations that require the physical presence of students, such as when a student is required to physically attend the exam, this is called a hybrid form of distance learning. This technology is increasingly used worldwide. The Internet has become the main communication channel for the development of distance learning.

  1. Distance learning perspectives.

    PubMed

    Pandza, Haris; Masic, Izet

    2013-01-01

    The development of modern technology and the Internet has enabled the explosive growth of distance learning. distance learning is a process that is increasingly present in the world. This is the field of education focused on educating students who are not physically present in the traditional classrooms or student's campus. described as a process where the source of information is separated from the students in space and time. If there are situations that require the physical presence of students, such as when a student is required to physically attend the exam, this is called a hybrid form of distance learning. This technology is increasingly used worldwide. The Internet has become the main communication channel for the development of distance learning. PMID:24222934

  2. Technology and Distance Education.

    ERIC Educational Resources Information Center

    Pelton, J. N.; Bates, A. W.

    1991-01-01

    Two articles evaluate the impact of new transmission and information technologies on education: "Technology and Education--Friend or Foe?" (Pelton) and "Third Generation Distance Education: The Challenge of New Technology" (Bates). (SK)

  3. Sexual tourism: implications for travelers and the destination culture.

    PubMed

    Marrazzo, Jeanne M

    2005-03-01

    Health care providers in a variety of settings need to improve their ability--along with the capabilities of supporting laboratories, surveillance systems, and services for sex partner management--to diagnose and treat STI. Whether the travel health care sector, as such, is willing to take on the additional burden of STI-related screening and risk reduction counseling has been raised by some authors. Currently, the burden of providing formalized STI care falls on the public sector; however, in the United States, most STI are actually diagnosed in the offices of private physicians. Given that the United States has the highest STI rates of any industrialized country, the undeniable synergy between STI and HIV acquisition, the failure of many American providers to screen for C trachomatis despite clear guidelines, the global resurgence of syphilis and extension of resistant N gonorrhoeae and of HIV, and the risk behaviors consistently reported by travelers, it is hard to argue against travel specialists' joining the daunting battle against these recalcitrant infections and their often devastating consequences. Most of the relevant diagnostic tests are relatively affordable, and patient-centered risk-reduction counseling, once mastered, can be brief and easily integrated into the overall conversation about protecting oneself during travel.

  4. Significant increase in travel-associated dengue fever in Germany.

    PubMed

    Allwinn, Regina

    2011-08-01

    Increasing numbers of dengue fever (DF) cases reflect the increasing travel mobility together with the expanding geographical distribution of the vector Aedes aegypti. Compared with earlier surveys in Germany, higher incidences occur and correlate well with ongoing outbreaks. Therefore, we investigated 767 serum samples from 594 returning travellers with suspected DF between 2005 and 2010, which where sent from different hospitals in the drainage area Frankfurt/Main. Established diagnostic assays were ELISA, immunofluorescence and chromatographic tests. We obtained 112 dengue-seropositive serum samples from totally 60 patients: the detection rate was 10.1% (60 out of 594). A significant increase was found in 2010. Most patients were aged between 40 and 49, and indirect immunofluorescence technique indicated mainly DF serotype 2. Actual data reveal a significant rise in imported DF cases in 2010 according to an increasing risk to acquire DF virus infection. Nevertheless, dengue haemorrhagic fever and dengue shock syndrome are still rare in travellers, but those with a history of dengue should be tested for DF serotypes and advised to protect themselves well from mosquitoes when travelling to endemic areas.

  5. Fundamental Travel Demand Model Example

    NASA Technical Reports Server (NTRS)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  6. Toxoplasmosis as a travel risk.

    PubMed

    Sepúlveda-Arias, Juan C; Gómez-Marin, Jorge E; Bobić, Branko; Naranjo-Galvis, Carlos A; Djurković-Djaković, Olgica

    2014-01-01

    Toxoplasma gondii is a protozoan parasite with worldwide distribution that infects more than one third of the global population. Primary infection in immunocompetent individuals is usually asymptomatic; however, different organs can be affected in immunocompromised individuals leading to the development of encephalitis, myocarditis or pneumonitis. The prevalence of infection with Toxoplasma as well as its genetic structure varies geographically and for that reason travel may be considered as a risk factor to acquire the infection. As toxoplasmosis is a foodborne disease, health care providers should give health education on prevention measures to all prospective travelers in order to decrease the risk of infection in endemic areas. This review presents an overview of the infection with T. gondii with some considerations for travelers to and from endemic zones. PMID:24951321

  7. Toxoplasmosis as a travel risk.

    PubMed

    Sepúlveda-Arias, Juan C; Gómez-Marin, Jorge E; Bobić, Branko; Naranjo-Galvis, Carlos A; Djurković-Djaković, Olgica

    2014-01-01

    Toxoplasma gondii is a protozoan parasite with worldwide distribution that infects more than one third of the global population. Primary infection in immunocompetent individuals is usually asymptomatic; however, different organs can be affected in immunocompromised individuals leading to the development of encephalitis, myocarditis or pneumonitis. The prevalence of infection with Toxoplasma as well as its genetic structure varies geographically and for that reason travel may be considered as a risk factor to acquire the infection. As toxoplasmosis is a foodborne disease, health care providers should give health education on prevention measures to all prospective travelers in order to decrease the risk of infection in endemic areas. This review presents an overview of the infection with T. gondii with some considerations for travelers to and from endemic zones.

  8. Schistosomiasis in Travelers and Expatriates.

    PubMed

    Jelinek; Nothdurft; Löscher

    1996-09-01

    Background: Several outbreaks of schistosomiasis among travelers, expatriates, and military serviceman have been reported in recent years. Methods: The travel histories and anamnestic and clinical features of 62 patients with schistosomiasis, who presented to a German outpatient clinic specializing in infectious and tropical diseases, were investigated to identify risk factors that could lead to infection in travelers and expatriates. Results: All patients remembered incidents that led to a likely exposure to cercariae of Schistosoma sp. Fifty nine patients (95%) acquired infection in Africa, two (3%) in South America, and one each (2% each) in Iraq and the Mekong River, respectively. The highest proportion of infection (45%) was imported from West Africa. Patients returning from West Africa reported either contact with tributaries of the Niger (including freshwater pools in the Dogon country, Mali) or with waters of the Volta River, notably Lake Volta and/or its delta. Six patients (10%) acquired infection in little-visited areas such as Central Africa and the Congo Basin. East Africa (especially Lake Victoria) and Lake Malawi contributed 14 patients (22%) to our study group; a further nine patients (14%) became infected after contact with waters of the Zambezi River. Conclusions: The most sensitive method for detection of possible infection with schistosomiasis appeared to be a combination of thorough travel history and serologic testing by indirect hemagglutination (IHA), immunofluorescence antibody test (IFAT), and enzyme-linked immunosorbent assay (ELISA). Most infections were acquired by travelers on lengthy and adventurous journeys or by expatriates venturing outside their normal areas of activity. Most patients knew that they had traveled in an area endemic for schistosomiasis, but were uninformed about behavioral risks they had taken in specific settings. PMID:9815445

  9. Schistosomiasis in Travelers and Expatriates.

    PubMed

    Jelinek; Nothdurft; Löscher

    1996-09-01

    Background: Several outbreaks of schistosomiasis among travelers, expatriates, and military serviceman have been reported in recent years. Methods: The travel histories and anamnestic and clinical features of 62 patients with schistosomiasis, who presented to a German outpatient clinic specializing in infectious and tropical diseases, were investigated to identify risk factors that could lead to infection in travelers and expatriates. Results: All patients remembered incidents that led to a likely exposure to cercariae of Schistosoma sp. Fifty nine patients (95%) acquired infection in Africa, two (3%) in South America, and one each (2% each) in Iraq and the Mekong River, respectively. The highest proportion of infection (45%) was imported from West Africa. Patients returning from West Africa reported either contact with tributaries of the Niger (including freshwater pools in the Dogon country, Mali) or with waters of the Volta River, notably Lake Volta and/or its delta. Six patients (10%) acquired infection in little-visited areas such as Central Africa and the Congo Basin. East Africa (especially Lake Victoria) and Lake Malawi contributed 14 patients (22%) to our study group; a further nine patients (14%) became infected after contact with waters of the Zambezi River. Conclusions: The most sensitive method for detection of possible infection with schistosomiasis appeared to be a combination of thorough travel history and serologic testing by indirect hemagglutination (IHA), immunofluorescence antibody test (IFAT), and enzyme-linked immunosorbent assay (ELISA). Most infections were acquired by travelers on lengthy and adventurous journeys or by expatriates venturing outside their normal areas of activity. Most patients knew that they had traveled in an area endemic for schistosomiasis, but were uninformed about behavioral risks they had taken in specific settings.

  10. Travel epidemiology: the Saudi perspective.

    PubMed

    Memish, Ziad A; Venkatesh, S; Ahmed, Qanta A

    2003-02-01

    The Kingdom of Saudi Arabia occupies four-fifths of the Arabian Peninsula, with a land area of 2 million square kilometres. Saudi Arabia holds a unique position in the Islamic world, as the custodian of the two holiest places of Islam, in Mecca and Medina. Annually, some 2 million Muslims from over 140 countries embark on Hajj. This extraordinary en masse migration is a unique forum for the study of travel epidemiology since the Hajj carries various health risks, both communicable and non-communicable, often on a colossal scale. Non-communicable hazards of the Hajj include stampede and motor vehicle trauma, fire-related burn injuries and accidental hand injury during animal slaughter. Communicable hazards in the form of outbreaks of multiple infectious diseases have been reported repeatedly, during and following the Hajj. Meningococcal meningitis, gastroenteritis, hepatitis A, B and C, and various zoonotic diseases comprise some of the possible infectious hazards at the Hajj. Many of these infectious and non-infectious hazards can be avoided or averted by adopting appropriate prophylactic measures. Physicians and health personnel must be aware of these risks to appropriately educate, immunize and prepare these travellers facing the unique epidemiological challenges of Hajj in an effort to minimize untoward effects. Travel epidemiology related to the Hajj is a new and exciting area, which offers valuable insights to the travel specialist. The sheer scale of numbers affords a rare view of migration medicine in action. As data is continually gathered and both national and international policy making is tailored to vital insights gained through travel epidemiology, the Hajj will be continually safeguarded. Practitioners will gain from findings of travel related epidemiological changes in evolution at the Hajj: the impact of vaccinating policies, infection control policies and public health are afforded a real-world laboratory setting at each annual Hajj, allowing us to

  11. Developing Human Resources through Actualizing Human Potential

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    2012-01-01

    The key to human resource development is in actualizing individual and collective thinking, feeling and choosing potentials related to our minds, hearts and wills respectively. These capacities and faculties must be balanced and regulated according to the standards of truth, love and justice for individual, community and institutional development,…

  12. [Actual diet of patients with gastrointestinal diseases].

    PubMed

    Loranskaia, T I; Shakhovskaia, A K; Pavliuchkova, M S

    2000-01-01

    The study of actual nutrition of patients with erosive-ulcerative lesions in the gastroduodenal zone and of patients with operated ulcer has revealed defects in intake of essential nutrients by these patients: overeating of animal fat and refined carbohydrates, deficiency of oil, vitamins A, B2, C, D and food fibers.

  13. Humanistic Education and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1984-01-01

    Stresses the need for theoretical justification for the development of humanistic education programs in today's schools. Explores Abraham Maslow's hierarchy of needs and theory of self-actualization. Argues that Maslow's theory may be the best available for educators concerned with educating the whole child. (JHZ)

  14. Group Counseling for Self-Actualization.

    ERIC Educational Resources Information Center

    Streich, William H.; Keeler, Douglas J.

    Self-concept, creativity, growth orientation, an integrated value system, and receptiveness to new experiences are considered to be crucial variables to the self-actualization process. A regular, year-long group counseling program was conducted with 85 randomly selected gifted secondary students in the Farmington, Connecticut Public Schools. A…

  15. Teenagers' Perceived and Actual Probabilities of Pregnancy.

    ERIC Educational Resources Information Center

    Namerow, Pearila Brickner; And Others

    1987-01-01

    Explored adolescent females' (N=425) actual and perceived probabilities of pregnancy. Subjects estimated their likelihood of becoming pregnant the last time they had intercourse, and indicated the dates of last intercourse and last menstrual period. Found that the distributions of perceived probability of pregnancy were nearly identical for both…

  16. Black Holes: A Traveler's Guide

    NASA Astrophysics Data System (ADS)

    Pickover, Clifford A.

    1998-03-01

    BLACK HOLES A TRAVELER'S GUIDE Clifford Pickover's inventive and entertaining excursion beyond the curves of space and time. "I've enjoyed Clifford Pickover's earlier books . . . now he has ventured into the exploration of black holes. All would-be tourists are strongly advised to read his traveler's guide." -Arthur C. Clarke. "Many books have been written about black holes, but none surpass this one in arousing emotions of awe and wonder towards the mysterious structure of the universe." -Martin Gardner. "Bucky Fuller thought big. Arthur C. Clarke thinks big, but Cliff Pickover outdoes them both." -Wired. "The book is fun, zany, in-your-face, and refreshingly addictive." -Times Higher Education Supplement.

  17. Navigation: traveling the water highways!

    USGS Publications Warehouse

    Fisher, Marion; Vandas, Stephen; Farrar, Frank

    1996-01-01

    NAVIGATION is travel or transportation over water. Many different kinds of boats and ships are used on rivers and oceans to move people and products from one place to another. Navigation was extremely important for foreign and domestic trade and travel in the early days of our country before cars, trucks, trains, and airplanes were invented. In those days, rivers were used as "roads" to connect inland settlements to river and coastal ports. Communities established at these commercial ports became important economic, cultural, and social hubs in the development of our Nation.

  18. [Travel and chronic respiratory insufficiency].

    PubMed

    Bonnet, D; Marotel, C; Miltgen, J; N'Guyen, G; Cuguilliere, A; L'Her, P

    1997-01-01

    Changes in climate, altitude and lifestyle during travel confronts patients presenting chronic respiratory insufficiency with special problems. A major challenge is related to high altitude during air travel. To limit risks, a preflight examination is necessary to ascertain respiratory status. Patients requiring oxygen therapy must ensure availability both during the flight and at the destination. Patients with asthma or chronic bronchitis must bring along a sufficient supply of usual inhalers. All patients should carry a doctor's letter describing their condition and listing medications. Using these elementary precautions, patients with chronic respiratory insufficiency can safely enjoy sightseeing and outdoor leisure activities.

  19. Fever in the returned traveler.

    PubMed

    Strickland, G T

    1992-11-01

    Febrile infections can be fatal in travelers to tropical countries unless the patient seeks medical care in a timely manner and the physician takes the time and has the skill to make a rapid diagnosis and prescribe appropriate therapy. In addition to the usual febrile illnesses present in temperate climates, the patient may have an "exotic" infection, e.g., malaria, infectious hepatitis, enteric fever, or dengue fever. The potential causes of fever in travelers are extensive. This article provides practical clues to assist the physician in making the correct diagnosis--by using exposure information, symptoms and signs, and concomitant symptom complexes.

  20. Cosmic-string traveling waves

    NASA Astrophysics Data System (ADS)

    Garfinkle, David

    1991-08-01

    An attempt to solve Einstein's equations by assuming the existence of symmetries and by treating metrics that possess a Killing vector is presented. A spacetime with a null Killing field can be regarded as the history of a disturbance that propagates at the speed of light without changing its amplitude or shape. Such spacetimes are referred to as traveling waves. A new technique for generating solutions of Einstein's equations is then presented. The technique produces a new traveling wave spacetime given an old one. It applies to both the vacuum Einstein equations and Einstein's equations coupled to various types of matter.

  1. Collection Development "Mini-Travel Guides": Traveling Light

    ERIC Educational Resources Information Center

    Kaufmann, Linda M.

    2009-01-01

    Predictions regarding how much traveling Americans will be doing this year and where they might go vary, but it is expected that many will cut back on what is increasingly considered a luxury. Even so, gasoline prices are down substantially from a year ago, the stronger dollar means better prices in Europe, and there are discounts in all areas of…

  2. Meeting the Needs of Distance Learners of M.Ed Program: Bangladesh Open University Perspective

    ERIC Educational Resources Information Center

    Islam, Amirul; Ferdowsi, Sakiba

    2014-01-01

    This study draws on the experience of a cohort of 22 students from 09 tutorial centers enrolled in a Master of Education (M Ed) distance learning program administered by the Bangladesh Open University (BOU). It's purpose is to locate the aims and philosophies of distance learning within the experiences of actual distance learners in order to…

  3. Quantifying the Effect of Fast Charger Deployments on Electric Vehicle Utility and Travel Patterns via Advanced Simulation: Preprint

    SciTech Connect

    Wood, E.; Neubauer, J.; Burton, E.

    2015-02-01

    The disparate characteristics between conventional (CVs) and battery electric vehicles (BEVs) in terms of driving range, refill/recharge time, and availability of refuel/recharge infrastructure inherently limit the relative utility of BEVs when benchmarked against traditional driver travel patterns. However, given a high penetration of high-power public charging combined with driver tolerance for rerouting travel to facilitate charging on long-distance trips, the difference in utility between CVs and BEVs could be marginalized. We quantify the relationships between BEV utility, the deployment of fast chargers, and driver tolerance for rerouting travel and extending travel durations by simulating BEVs operated over real-world travel patterns using the National Renewable Energy Laboratory's Battery Lifetime Analysis and Simulation Tool for Vehicles (BLAST-V). With support from the U.S. Department of Energy's Vehicle Technologies Office, BLAST-V has been developed to include algorithms for estimating the available range of BEVs prior to the start of trips, for rerouting baseline travel to utilize public charging infrastructure when necessary, and for making driver travel decisions for those trips in the presence of available public charging infrastructure, all while conducting advanced vehicle simulations that account for battery electrical, thermal, and degradation response. Results from BLAST-V simulations on vehicle utility, frequency of inserted stops, duration of charging events, and additional time and distance necessary for rerouting travel are presented to illustrate how BEV utility and travel patterns can be affected by various fast charge deployments.

  4. 75 FR 24434 - Federal Travel Regulation (FTR); Transportation in Conjunction With Official Travel and Relocation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... ``Official travel'' and ``Transit system''; clarifies reimbursement for transportation at an official station... and definitions for ``Official travel'' and ``Transit system'' and also removes references to ``local travel,'' ``local transit system,'' ``local transportation,'' ``local transportation system,''...

  5. Distance from forest edge affects bee pollinators in oilseed rape fields

    PubMed Central

    Bailey, Samantha; Requier, Fabrice; Nusillard, Benoît; Roberts, Stuart P M; Potts, Simon G; Bouget, Christophe

    2014-01-01

    Wild pollinators have been shown to enhance the pollination of Brassica napus (oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops. In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yellow pan traps at increasing distances from both warm and cold forest edges into B. napus fields during the blooming period. A total of 4594 individual bees, representing six families and 83 taxa, were collected. We found that both bee abundance and taxa richness were negatively affected by the distance from forest edge. However, responses varied between bee groups and edge orientations. The ITD (Inter-Tegular distance) of the species, a good proxy for bee foraging range, seems to limit how far the bees can travel from the forest edge. We found a greater abundance of cuckoo bees (Nomada spp.) of Andrena spp. and Andrena spp. males at forest edges, which we assume indicate suitable nesting sites, or at least mating sites, for some abundant Andrena species and their parasites (Fig. 1). Synthesis and Applications. This study provides one of the first examples in temperate ecosystems of how forest edges may actually act as a reservoir of potential pollinators and directly benefit agricultural crops by providing nesting or mating sites for important early spring pollinators. Policy-makers and land managers should take forest edges into account and encourage their protection in the agricultural matrix to promote wild bees and their pollination services. PMID:24634722

  6. Distance from forest edge affects bee pollinators in oilseed rape fields.

    PubMed

    Bailey, Samantha; Requier, Fabrice; Nusillard, Benoît; Roberts, Stuart P M; Potts, Simon G; Bouget, Christophe

    2014-02-01

    Wild pollinators have been shown to enhance the pollination of Brassica napus (oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops. In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yellow pan traps at increasing distances from both warm and cold forest edges into B. napus fields during the blooming period. A total of 4594 individual bees, representing six families and 83 taxa, were collected. We found that both bee abundance and taxa richness were negatively affected by the distance from forest edge. However, responses varied between bee groups and edge orientations. The ITD (Inter-Tegular distance) of the species, a good proxy for bee foraging range, seems to limit how far the bees can travel from the forest edge. We found a greater abundance of cuckoo bees (Nomada spp.) of Andrena spp. and Andrena spp. males at forest edges, which we assume indicate suitable nesting sites, or at least mating sites, for some abundant Andrena species and their parasites (Fig. 1). Synthesis and Applications. This study provides one of the first examples in temperate ecosystems of how forest edges may actually act as a reservoir of potential pollinators and directly benefit agricultural crops by providing nesting or mating sites for important early spring pollinators. Policy-makers and land managers should take forest edges into account and encourage their protection in the agricultural matrix to promote wild bees and their pollination services.

  7. Distance from forest edge affects bee pollinators in oilseed rape fields.

    PubMed

    Bailey, Samantha; Requier, Fabrice; Nusillard, Benoît; Roberts, Stuart P M; Potts, Simon G; Bouget, Christophe

    2014-02-01

    Wild pollinators have been shown to enhance the pollination of Brassica napus (oilseed rape) and thus increase its market value. Several studies have previously shown that pollination services are greater in crops adjoining forest patches or other seminatural habitats than in crops completely surrounded by other crops. In this study, we investigated the specific importance of forest edges in providing potential pollinators in B. napus fields in two areas in France. Bees were caught with yellow pan traps at increasing distances from both warm and cold forest edges into B. napus fields during the blooming period. A total of 4594 individual bees, representing six families and 83 taxa, were collected. We found that both bee abundance and taxa richness were negatively affected by the distance from forest edge. However, responses varied between bee groups and edge orientations. The ITD (Inter-Tegular distance) of the species, a good proxy for bee foraging range, seems to limit how far the bees can travel from the forest edge. We found a greater abundance of cuckoo bees (Nomada spp.) of Andrena spp. and Andrena spp. males at forest edges, which we assume indicate suitable nesting sites, or at least mating sites, for some abundant Andrena species and their parasites (Fig. 1). Synthesis and Applications. This study provides one of the first examples in temperate ecosystems of how forest edges may actually act as a reservoir of potential pollinators and directly benefit agricultural crops by providing nesting or mating sites for important early spring pollinators. Policy-makers and land managers should take forest edges into account and encourage their protection in the agricultural matrix to promote wild bees and their pollination services. PMID:24634722

  8. Presence at a distance.

    PubMed

    Haddouk, Lise

    2015-01-01

    Nowadays in the context of the cyberculture, computer-mediated inter-subjective relationships are part of our everyday lives, in both the professional and personal spheres, and for all age groups. In the clinical field, many applications have been developed to facilitate the exchange of informations and mediate the relationship between patient and therapist. In psychology, more or less immersive technologies are used, to encourage the feeling of presence among the users, and to trigger certain psychological processes. In our research, we have explored the remote clinical interview through videoconferencing, with the development and utilisation of the iPSY platform, totally focused on this objective. In this context, we have considered the notion of intersubjectivity, despite the physical absence. This research is leading us today to envision the notions of distance and presence, and possibly to redefine them. Thus, can we still oppose physical distance to psychological distance? Can we still affirm that the physical absence does not permit a psychological co-presence in certain interactions, like this observed in video interviews? The results show that the psychological processes, activated in this context, are similar to those observed in "traditional" clinical consults between the patient and the therapist. However, certain specifics have led us to consider the concept of distance, here influenced by the framework, and to observe its effects. This distance could possibly constitute a therapeutic lever for some patients, notably for those who have difficulties establishing the right psychological distance in their relationships with others. According to these results, can "distance" still be opposed to "presence", or could it be re-defined? This also opens up questions on the more general concept of digital relationships, and the definition of their specificities. PMID:26799909

  9. Prevention and control of rabies in an age of global travel: a review of travel- and trade-associated rabies events--United States, 1986-2012.

    PubMed

    Lankau, E W; Cohen, N J; Jentes, E S; Adams, L E; Bell, T R; Blanton, J D; Buttke, D; Galland, G G; Maxted, A M; Tack, D M; Waterman, S H; Rupprecht, C E; Marano, N

    2014-08-01

    Rabies prevention and control efforts have been successful in reducing or eliminating virus circulation regionally through vaccination of specific reservoir populations. A notable example of this success is the elimination of canine rabies virus variant from the United States and many other countries. However, increased international travel and trade can pose risks for rapid, long-distance movements of ill or infected persons or animals. Such travel and trade can result in human exposures to rabies virus during travel or transit and could contribute to the re-introduction of canine rabies variant or transmission of other viral variants among animal host populations. We present a review of travel- and trade-associated rabies events that highlight international public health obligations and collaborative opportunities for rabies prevention and control in an age of global travel. Rabies is a fatal disease that warrants proactive coordination among international public health and travel industry partners (such as travel agents, tour companies and airlines) to protect human lives and to prevent the movement of viral variants among host populations.

  10. Effects of Horizontal Magnetic Fields on Acoustic Travel Times

    NASA Astrophysics Data System (ADS)

    Jain, Rekha

    2007-02-01

    Local helioseismology techniques seek to probe the subsurface magnetic fields and flows by observing waves that emerge at the solar surface after passing through these inhomogeneities. Active regions on the surface of the Sun are distinguished by their strong magnetic fields, and techniques such as time-distance helioseismology can provide a useful diagnostic for probing these structures. Above the active regions, the fields fan out to create a horizontal magnetic canopy. We investigate the effect of a uniform horizontal magnetic field on the travel time of acoustic waves by considering vertical velocity in a simple plane-parallel adiabatically stratified polytrope. It is shown that such fields can lower the upper turning point of p-modes and hence influence their travel time. It is found that acoustic waves reflected from magnetically active regions have travel times up to a minute less than for waves similarly reflected in quiet regions. It is also found that sound speeds are increased below the active regions. These findings are consistent with time-distance measurements.

  11. Experimental Results of Guided Wave Travel Time Tomography

    NASA Astrophysics Data System (ADS)

    Volker, Arno; Bloom, Joost

    2011-06-01

    Corrosion is one of the industries major issues regarding the integrity of assets. Currently inspections are conducted at regular intervals to ensure a sufficient integrity level of these assets. Cost reduction while maintaining a high level of reliability and safety of installations is a major challenge. The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation matches very well with the objective to reduce cost while maintaining a high safety level. Guided waves are very attractive for permanent monitoring systems because they can travel over large distances and therefore provide the essential large area coverage. Making use of the dispersive behavior of the guided waves, a wall thickness map over a distance of several meters can be made using only two rings of guided wave transducers. Travel time tomography is used to translate transmission travel times into a wall thickness map. This method has been applied in the field for the first time to map the wall thickness under two clearly corroded pipe supports of a 8″ and 10″ gas pipe line. The tomographic inversion results clearly maps the corrosion under the supports. Independent reference measurements confirm the tomographic inversion results.

  12. Commercial Space Travel, Ethics and Society

    NASA Astrophysics Data System (ADS)

    Cox, N. L. J.

    2002-01-01

    For the past two decades interest in the possibilities of commercial (manned) space travel or space tourism has increased among engineers, scientists, entrepreneurs and also citizens. A continuously growing collection of papers is being published on space tourism itself and associated subjects, like new reusable launch vehicles, space habitats, space entertainment and corresponding law and regulation. Market research promises sufficient interest in tourist space travel to take off and develop into a multi billion-dollar business. The basic engineering knowledge and expertise is available to start development and designing of safe and affordable reusable vertical lift off and landing vehicles, like the Kankoh-Maru. However, many issues remain fairly untouched in literature. These include, for example, regulations, law, international agreement on space traffic control and also insurance policy. One important topic however has been barely touched upon. This concerns the ethical issues in commercial (manned) space travel, which need to be considered thoroughly, preferably before actual take off of the first regular space tourist services. The answer to the latter question comprises the major part of the paper. First, the paper deals with the issue of who wants, needs and will go to space at what stage in the development of the space tourism industry. A schematic pyramid differentiating between several community groups is made. Secondly, it discusses the way we can and should deal with our environment. Space is still fairly unspoiled, although there is a lot of (government) debris out there. Rules of the space tourist game need to be established. A few general directions are presented, for example on debris cleaning and garbage disposal. Also our right to exploit the asteroids and the moon for material is discussed. In the last part of this paper, the risks involved with the harsh environment of space are considered. Is it safe and responsible to eject people into outer

  13. Long distance entanglement distribution

    NASA Astrophysics Data System (ADS)

    Broadfoot, Stuart Graham

    Developments in the interdisciplinary field of quantum information open up previously impossible abilities in the realms of information processing and communication. Quantum entanglement has emerged as one property of quantum systems that acts as a resource for quantum information processing and, in particular, enables teleportation and secure cryptography. Therefore, the creation of entangled resources is of key importance for the application of these technologies. Despite a great deal of research the efficient creation of entanglement over long distances is limited by inevitable noise. This problem can be overcome by creating entanglement between nodes in a network and then performing operations to distribute the entanglement over a long distance. This thesis contributes to the field of entanglement distribution within such quantum networks. Entanglement distribution has been extensively studied for one-dimensional networks resulting in "quantum repeater" protocols. However, little work has been done on higher dimensional networks. In these networks a fundamentally different scaling, called "long distance entanglement distribution", can appear between the resources and the distance separating the systems to be entangled. I reveal protocols that enable long distance entanglement distribution for quantum networks composed of mixed state and give a few limitations to the capabilities of entanglement distribution. To aid in the implementation of all entanglement distribution protocols I finish by introducing a new system, composed of an optical nanofibre coupled to a carbon nanotube, that may enable new forms of photo-detectors and quantum memories.

  14. Sex difference in travel is concentrated in adolescence and tracks reproductive interests

    PubMed Central

    Miner, Emily J.; Gurven, Michael; Kaplan, Hillard; Gaulin, Steven J. C.

    2014-01-01

    Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager–horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men's and women's travel behaviour reflects differential gains from mate search and parenting across the life course. PMID:25320169

  15. Sex difference in travel is concentrated in adolescence and tracks reproductive interests.

    PubMed

    Miner, Emily J; Gurven, Michael; Kaplan, Hillard; Gaulin, Steven J C

    2014-12-01

    Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager-horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men's and women's travel behaviour reflects differential gains from mate search and parenting across the life course. PMID:25320169

  16. On the Miller-Tucker-Zemlin Based Formulations for the Distance Constrained Vehicle Routing Problems

    NASA Astrophysics Data System (ADS)

    Kara, Imdat

    2010-11-01

    Vehicle Routing Problem (VRP), is an extension of the well known Traveling Salesman Problem (TSP) and has many practical applications in the fields of distribution and logistics. When the VRP consists of distance based constraints it is called Distance Constrained Vehicle Routing Problem (DVRP). However, the literature addressing on the DVRP is scarce. In this paper, existing two-indexed integer programming formulations, having Miller-Tucker-Zemlin based subtour elimination constraints, are reviewed. Existing formulations are simplified and obtained formulation is presented as formulation F1. It is shown that, the distance bounding constraints of the formulation F1, may not generate the distance traveled up to the related node. To do this, we redefine the auxiliary variables of the formulation and propose second formulation F2 with new and easy to use distance bounding constraints. Adaptation of the second formulation to the cases where new restrictions such as minimal distance traveled by each vehicle or other objectives such as minimizing the longest distance traveled is discussed.

  17. Inspection of the Secretary of Energy`s foreign travel

    SciTech Connect

    1996-10-07

    On December 9, 1995, the Secretary of Energy requested that the Department`s Inspector General (IG) conduct a thorough examination of all Secretarial foreign travel from 1993 to December 1995 to include the purpose of each trip, the activities of each Federal participant in each trip, the funding of each trip, and claims for reimbursements for expenses by Federal trip participants. The Secretary also requested that the review include an assessment of travel authorization, voucher, traveler reimbursement, and auditing systems employed by the Department to identify steps that could be taken to reduce errors and improve accounting oversight. Additionally, the Secretary requested that the Inspector General conduct a thorough examination of the establishment and filling of the Department`s Ombudsman position. The Office of Inspector General (OIG) initiated a review into these matters and assigned primary responsibility for the review to the Office of Inspections. The purpose of this inspection was to conduct a thorough examination of the 16 Secretarial foreign trips from June 1993 to December 1995. This report focuses on the four trade missions because of their extent and cost. We examined a number of Departmental management systems and processes involved in planning and executing the 16 foreign trips. To determine the actual cost of the 16 trips, it was necessary to determine who participated in the trips and to identify the individual travel costs. We were required to perform extensive reviews of records and conduct a large number of interviews because the Department could not provide any specific documents that could accurately account for who actually participated on the 16 trips. Having identified who participated, it was then necessary to examine key aspects of the Department`s management systems. Our report contains 31 recommendations for corrective action.

  18. Time Travel in the Library

    ERIC Educational Resources Information Center

    Brown, Donna W.

    2005-01-01

    A Time Travel project in the library gives enthusiasm to students to connect with the past and reinforces their research skills while instilling respect for the past years. The librarian should choose one specific decade to highlight in the library and create an extravaganza that would allow memorabilia from that time period to be located without…

  19. Your Travel Dollar. Money Management.

    ERIC Educational Resources Information Center

    Baran, Nancy H., Ed.

    This illustrated guide was designed to familiarize consumers with planning a vacation trip, whether domestic or abroad. The guide covers setting up a budget; package tours; cruises and charter flights; travel agencies and clubs; and arranging stays in hotels/motels, rental condominiums, bed-and-breakfasts, hostels, campsites, and private…

  20. Music Travel: Avoiding the Potholes

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2010-01-01

    Even given the countless hours clocked in class and rehearsal time, there's nothing that compares to a road trip to seal the bond among band, orchestra, and vocal music students. "Nothing can replace travel," says Peter Markes, orchestra director at Edmond North High School in Oklahoma. "It's safe, well-structured and, for many of the kids, it's…

  1. Transition Matrices and Time Travel

    NASA Astrophysics Data System (ADS)

    Lee, Hwee Kuan

    It has been proven by Lee [1] that the grandfather paradox and Deutsch's unproven paradox are precluded for twoand three-state graphical models. We prove that both paradoxes are also precluded for a general n-state model. In addition, we present a new time travel paradox in this paper.

  2. Preparing Students for Travel Abroad.

    ERIC Educational Resources Information Center

    Novotny, Jeanne

    1989-01-01

    This article outlines information which can be provided by the school nurse or health educator to help make student trips abroad healthy as well as educational. Topics covered include: food and water, traveler's diarrhea, handwashing, insect and animal bites, stress, and prior health problems. (IAH)

  3. Stereoscopic distance perception

    NASA Technical Reports Server (NTRS)

    Foley, John M.

    1989-01-01

    Limited cue, open-loop tasks in which a human observer indicates distances or relations among distances are discussed. By open-loop tasks, it is meant tasks in which the observer gets no feedback as to the accuracy of the responses. What happens when cues are added and when the loop is closed are considered. The implications of this research for the effectiveness of visual displays is discussed. Errors in visual distance tasks do not necessarily mean that the percept is in error. The error could arise in transformations that intervene between the percept and the response. It is argued that the percept is in error. It is also argued that there exist post-perceptual transformations that may contribute to the error or be modified by feedback to correct for the error.

  4. L'energie sombre: Un mirage cosmique? Luminosity distance {ne} proper distance: A cosmological dissimilitude induced by nonlinear electrodynamics

    SciTech Connect

    Mosquera Cuesta, Herman J.

    2010-06-23

    The current understanding of our universe is built upon the information that we extract from light coming from cosmological sources like far-away galaxies, quasars, supernovae, gamma-ray bursts, etc, including the emission in radio wavelengths of those sources. The particular analysis of supernovae type Ia (SNIa) observations has led to the idea that the universe is undergoing a late-time accelerate phase which started when it was at redshift z{approx}1. The redshift z is a cosmological parameter inferred from observations of emission (or absorption) lines from the expanding SNIa debris or from the supernova host galaxy, presuming the light properties and interactions, as described by Maxwell's theory, do not change while it travels through the intervening intergalactic magnetic fields. In this paper we demonstrate that the nonlinear electrodynamics (NLED) description of photon propagation through the weak background intergalactic magnetic fields introduces a fundamental modification of the cosmological redshift, as compared to the one that a direct computation within a specific cosmological model ascribes to a distant source. It is shown that independently of the class of NLED Lagrangian, the effective redshift turns out to be (1+z)|{sub eff} = (1+z){Delta}, where {Delta} {identical_to} (1+{Phi}{sub e})/(1+{Phi}{sub o}), with {Phi} {identical_to} 8/3(L{sub FF}/L{sub F})B{sup 2} being L{sub F} = dL/dF, L{sub FF} = d{sup 2}L/dF{sup 2}, the field F {identical_to} F{sub {alpha}{beta}F}{sup {alpha}{beta},} and B the magnetic field strength. It comes out that for field strengths as those estimated over the intergalactic space the effective redshift is always much lower than the standard redshift, and it recovers such limit when the NLED correction {Delta}({Phi}{sub e},{Phi}{sub o}){yields}1. Since we do not actually ever observe proper distances, then one can argue that for a particular redshift the observed luminosity distance of the light-emitting far-away source is

  5. L'energie sombre: Un mirage cosmique? Luminosity distance ≠ proper distance: A cosmological dissimilitude induced by nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Mosquera Cuesta, Herman J.

    2010-06-01

    The current understanding of our universe is built upon the information that we extract from light coming from cosmological sources like far-away galaxies, quasars, supernovae, gamma-ray bursts, etc, including the emission in radio wavelengths of those sources. The particular analysis of supernovae type Ia (SNIa) observations has led to the idea that the universe is undergoing a late-time accelerate phase which started when it was at redshift z~1. The redshift z is a cosmological parameter inferred from observations of emission (or absorption) lines from the expanding SNIa debris or from the supernova host galaxy, presuming the light properties and interactions, as described by Maxwell's theory, do not change while it travels through the intervening intergalactic magnetic fields. In this paper we demonstrate that the nonlinear electrodynamics (NLED) description of photon propagation through the weak background intergalactic magnetic fields introduces a fundamental modification of the cosmological redshift, as compared to the one that a direct computation within a specific cosmological model ascribes to a distant source. It is shown that independently of the class of NLED Lagrangian, the effective redshift turns out to be (1+z)|eff = (1+z)Δ, where Δ ≡ (1+Φe)/(1+φo), with φ ≡ 8/3(LFF/LF)B2 being LF = dL/dF, LFF = d2L/dF2, the field F ≡ FαβFαβ, and B the magnetic field strength. It comes out that for field strengths as those estimated over the intergalactic space the effective redshift is always much lower than the standard redshift, and it recovers such limit when the NLED correction Δ(φe,φo)-->1. Since we do not actually ever observe proper distances, then one can argue that for a particular redshift the observed luminosity distance of the light-emitting far-away source is different. The implications of this result for cosmography studies using SNIa (and gamma-ray bursts) are discussed.

  6. Emerging distance degree programs.

    PubMed

    Birnbaum, D; Greenhalgh, T

    2000-01-01

    The variation in program focus and style is examined in this column, which also identifies resources for evaluation. The integration of Web-based or other distance modality materials to conventional courses, and the expansion of traditional universities to include a virtual campus, should proceed with caution and systematic evaluation. It is an evolution that offers both rewards and pitfalls, but requires more rigorous examination. This article provides information about pedagogical issues and additional distance-education master's degree programs. Some are new, while others are established.

  7. Reproducing Actual Morphology of Planetary Lava Flows

    NASA Astrophysics Data System (ADS)

    Miyamoto, H.; Sasaki, S.

    1996-03-01

    Assuming that lava flows behave as non-isothermal laminar Bingham fluids, we developed a numerical code of lava flows. We take the self gravity effects and cooling mechanisms into account. The calculation method is a kind of cellular automata using a reduced random space method, which can eliminate the mesh shape dependence. We can calculate large scale lava flows precisely without numerical instability and reproduce morphology of actual lava flows.

  8. The Actual Apollo 13 Prime Crew

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The actual Apollo 13 lunar landing mission prime crew from left to right are: Commander, James A. Lovell Jr., Command Module pilot, John L. Swigert Jr.and Lunar Module pilot, Fred W. Haise Jr. The original Command Module pilot for this mission was Thomas 'Ken' Mattingly Jr. but due to exposure to German measles he was replaced by his backup, Command Module pilot, John L. 'Jack' Swigert Jr.

  9. Physical forces exerted by microbubbles on a surface in a traveling wave field.

    PubMed

    Brems, S; Hauptmann, M; Camerotto, E; Mertens, P W; Heyns, M; Struyf, H; De Gendt, S

    2014-02-01

    The effect of a wave with a varying traveling component on the bubble activity as well as the physical force generated by microbubbles on a surface has been studied. The acoustic emission from a collection of bubbles is measured in a 928 kHz sound field. Particle removal tests on a surface, which actually measures the applied physical force by the bubbles on that surface, indicate a very strong dependence on the angle of incidence. In other words, when the traveling wave component is maximized, the average physical force applied by microbubbles reaches a maximum. Almost complete particle removal for 78 nm silica particles was obtained for a traveling wave, while particle removal efficiency was reduced to only a few percent when a standing wave was applied. This increase in particle removal for a traveling wave is probably caused by a decrease in bubble trapping at nodes and antinodes in a standing wave field.

  10. The practice of travel medicine in Europe.

    PubMed

    Schlagenhauf, P; Santos-O'Connor, F; Parola, P

    2010-03-01

    Europe, because of its geographical location, strategic position on trade routes, and colonial past, has a long history of caring for travellers' health. Within Europe, there is great diversity in the practice of travel medicine. Some countries have travel medicine societies and provisions for a periodic distribution of recommendations, but many countries have no national pre-travel guidelines and follow international recommendations such as those provided by the WHO. Providers of travel medicine include tropical medicine specialists, general practice nurses and physicians, specialist 'travel clinics', occupational physicians, and pharmacists. One of the core functions of the European Centre for Disease Prevention and Control-funded network of travel and tropical medicine professionals, EuroTravNet, is to document the status quo of travel medicine in Europe. A three-pronged approach is used, with a real-time online questionnaire, a structured interview with experts in each country, and web searching.

  11. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  12. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  13. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  14. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  15. 49 CFR 230.76 - Piston travel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Maximum piston travel. The maximum piston travel when steam locomotive is standing shall be as follows... Driving Wheel Brake 6 Engine Truck Brake 8 Tender Brake 9...

  16. Network Structure and Travel Time Perception

    PubMed Central

    Parthasarathi, Pavithra; Levinson, David; Hochmair, Hartwig

    2013-01-01

    The purpose of this research is to test the systematic variation in the perception of travel time among travelers and relate the variation to the underlying street network structure. Travel survey data from the Twin Cities metropolitan area (which includes the cities of Minneapolis and St. Paul) is used for the analysis. Travelers are classified into two groups based on the ratio of perceived and estimated commute travel time. The measures of network structure are estimated using the street network along the identified commute route. T-test comparisons are conducted to identify statistically significant differences in estimated network measures between the two traveler groups. The combined effect of these estimated network measures on travel time is then analyzed using regression models. The results from the t-test and regression analyses confirm the influence of the underlying network structure on the perception of travel time. PMID:24204932

  17. Network structure and travel time perception.

    PubMed

    Parthasarathi, Pavithra; Levinson, David; Hochmair, Hartwig

    2013-01-01

    The purpose of this research is to test the systematic variation in the perception of travel time among travelers and relate the variation to the underlying street network structure. Travel survey data from the Twin Cities metropolitan area (which includes the cities of Minneapolis and St. Paul) is used for the analysis. Travelers are classified into two groups based on the ratio of perceived and estimated commute travel time. The measures of network structure are estimated using the street network along the identified commute route. T-test comparisons are conducted to identify statistically significant differences in estimated network measures between the two traveler groups. The combined effect of these estimated network measures on travel time is then analyzed using regression models. The results from the t-test and regression analyses confirm the influence of the underlying network structure on the perception of travel time.

  18. Copyright and Distance Education.

    ERIC Educational Resources Information Center

    MacKnight, Carol B.

    2000-01-01

    Reports on three workshops offering copyright education for library and computer services staff and administrators. Topics covered included: copyright (e.g., the Copyright Act of 1976 and classroom teaching); digital distance education issues (application of fair use to on-line teaching); and compliance (under the Digital Millennium Copyright…

  19. Prospect of Distance Learning

    ERIC Educational Resources Information Center

    Rahman, Monsurur; Karim, Reza; Byramjee, Framarz

    2015-01-01

    Many educational institutions in the United States are currently offering programs through distance learning, and that trend is rising. In almost all spheres of education a developing country like Bangladesh needs to make available the expertise of the most qualified faculty to her distant people. But the fundamental question remains as to whether…

  20. Accreditation of Distance Learning

    ERIC Educational Resources Information Center

    Demirel, Ergün

    2016-01-01

    The higher education institutes aspire to gain reputation of quality having accreditation from internationally recognized awarding bodies. The accreditation leads and provides quality assurance for education. Although distance learning becomes a significant part of the education system in the 21st century, there is still a common opinion that the…

  1. Advances in Distance Learning.

    ERIC Educational Resources Information Center

    1999

    This document contains three symposium papers on advances in distance learning. "The Adoption of Computer Technology and Telecommunications: A Case Study" (Larry M. Dooley, Teri Metcalf, Ann Martinez) reports on a study of the possible applications of two theoretical models (Rogers' Diffusion of Innovations model and the Concerns-Based Adoption…

  2. Rapport in Distance Education

    ERIC Educational Resources Information Center

    Murphy, Elizabeth; Rodriguez-Manzanares, Maria A.

    2012-01-01

    Rapport has been recognized as important in learning in general but little is known about its importance in distance education (DE). The study we report on in this paper provides insights into the importance of rapport in DE as well as challenges to and indicators of rapport-building in DE. The study relied on interviews with 42 Canadian…

  3. Distance Learning Programming.

    ERIC Educational Resources Information Center

    Lucero, Jesus Ricardo; And Others

    This resource guide for distance learning information, courses, and programming covers: (1) audiographics programming by the Pennsylvania Teleteaching Project; (2) cable programming, including the Cable Alliance for Education's Cable in the Classroom projects, Consumer News and Business Channel, Nostalgia Television, PENNARAMA Channel, Silent…

  4. Distance Education Policy Framework.

    ERIC Educational Resources Information Center

    Oregon State System of Higher Education, Eugene.

    This description of the policy framework for Oregon's distance education program gives an overview of the progress to date, outlines five areas in which policy must be developed, and identifies a number of priorities among those areas. Progress is reported in the following areas: several initiatives that incorporate new telecommunications and…

  5. Going the Distance

    ERIC Educational Resources Information Center

    Barack, Lauren

    2005-01-01

    Sixty years ago, distance education probably involved a pen, paper, and secretarial classes conducted via snail mail. Today, students in ever-increasing numbers are more likely to link to the Internet to learn how to conjugate French verbs or dissect frogs in Advanced Placement courses, according to a new landmark study from the U. S. Department…

  6. Time-distance helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Jefferies, S. M.; Harvey, J. W.; Pomerantz, M. A.

    1993-01-01

    It is shown here that it is possible to extract time-distance information from temporal cross-correlations of the intensity fluctuation on the solar surface. This approach opens the way for seismic studies of local solar phenomena such subsurface inhomogeneities near sunspots and should help to refine global models of the internal velocity stratification in the sun.

  7. Misconceptions of Astronomical Distances

    ERIC Educational Resources Information Center

    Miller, Brian W.; Brewer, William F.

    2010-01-01

    Previous empirical studies using multiple-choice procedures have suggested that there are misconceptions about the scale of astronomical distances. The present study provides a quantitative estimate of the nature of this misconception among US university students by asking them, in an open-ended response format, to make estimates of the distances…

  8. Technology & Distance Learning Survey.

    ERIC Educational Resources Information Center

    Florida Human Resources Development, Inc., Gainesville.

    A survey was conducted to assess the current state of technology and distance learning awareness and usage in Florida's adult education and community-based programs. Data were gathered through a survey of 350 adult practitioners, literacy providers, community-based organizations and libraries throughout the state (125 responses [36 percent return…

  9. Encyclopedia of Distance Learning

    ERIC Educational Resources Information Center

    Howard, Caroline, Ed.; Boettecher, Judith, Ed.; Justice, Lorraine, Ed.; Schenk, Karen, Ed.; Rogers, Patricia, Ed.; Berg, Gary, Ed.

    2005-01-01

    The innovations in computer and communications technologies combined with on-going needs to deliver educational programs to students regardless of their physical locations, have lead to the innovation of distance education programs and technologies. To keep up with recent developments in both areas of technologies and techniques related to…

  10. Faculty and Distance Education.

    ERIC Educational Resources Information Center

    Saba, Farhad, Ed.

    1998-01-01

    Outlines the role of faculty and issues that need to be addressed early on if large-scale distance education is going to be successful. Discusses academic freedom; intellectual property; training; compensation; and royalties and revenue sharing. Notes the importance of active involvement by faculty in shaping the university of the future. (AEF)

  11. Circuity factors in ridesharing: the individual's travel decision. Final report, September 1983-April 1986

    SciTech Connect

    Fricker, J.D.; Habib, G.

    1986-06-01

    The extra distance that a member of a carpool travels, when compared with that person's drive-alone distance between home and work, is one of the negative aspects of ridesharing. It is also the key value in calculating the amount of fuel saved by those choosing this commuter mode. The report describes the examination of the CR values experienced by 206 individuals who share rides in or to a small urban area.

  12. The Cognition of Maximal Reach Distance in Parkinson's Disease

    PubMed Central

    Nagaoka, Masanori

    2016-01-01

    This study aimed to investigate whether the cognition of spatial distance in reaching movements was decreased in patients with Parkinson's disease (PD) and whether this cognition was associated with various symptoms of PD. Estimated and actual maximal reaching distances were measured in three directions in PD patients and healthy elderly volunteers. Differences between estimated and actual measurements were compared within each group. In the PD patients, the associations between “error in cognition” of reaching distance and “clinical findings” were also examined. The results showed that no differences were observed in any values regardless of dominance of hand and severity of symptoms. The differences between the estimated and actual measurements were negatively deviated in the PD patients, indicating that they tended to underestimate reaching distance. “Error in cognition” of reaching distance correlated with the items of posture in the motor section of the Unified Parkinson's Disease Rating Scale. This suggests that, in PD patients, postural deviation and postural instability might affect the cognition of the distance from a target object. PMID:27597927

  13. The Cognition of Maximal Reach Distance in Parkinson's Disease

    PubMed Central

    Nagaoka, Masanori

    2016-01-01

    This study aimed to investigate whether the cognition of spatial distance in reaching movements was decreased in patients with Parkinson's disease (PD) and whether this cognition was associated with various symptoms of PD. Estimated and actual maximal reaching distances were measured in three directions in PD patients and healthy elderly volunteers. Differences between estimated and actual measurements were compared within each group. In the PD patients, the associations between “error in cognition” of reaching distance and “clinical findings” were also examined. The results showed that no differences were observed in any values regardless of dominance of hand and severity of symptoms. The differences between the estimated and actual measurements were negatively deviated in the PD patients, indicating that they tended to underestimate reaching distance. “Error in cognition” of reaching distance correlated with the items of posture in the motor section of the Unified Parkinson's Disease Rating Scale. This suggests that, in PD patients, postural deviation and postural instability might affect the cognition of the distance from a target object.

  14. The Cognition of Maximal Reach Distance in Parkinson's Disease.

    PubMed

    Otsuki, Satoru; Nagaoka, Masanori

    2016-01-01

    This study aimed to investigate whether the cognition of spatial distance in reaching movements was decreased in patients with Parkinson's disease (PD) and whether this cognition was associated with various symptoms of PD. Estimated and actual maximal reaching distances were measured in three directions in PD patients and healthy elderly volunteers. Differences between estimated and actual measurements were compared within each group. In the PD patients, the associations between "error in cognition" of reaching distance and "clinical findings" were also examined. The results showed that no differences were observed in any values regardless of dominance of hand and severity of symptoms. The differences between the estimated and actual measurements were negatively deviated in the PD patients, indicating that they tended to underestimate reaching distance. "Error in cognition" of reaching distance correlated with the items of posture in the motor section of the Unified Parkinson's Disease Rating Scale. This suggests that, in PD patients, postural deviation and postural instability might affect the cognition of the distance from a target object. PMID:27597927

  15. The Cognition of Maximal Reach Distance in Parkinson's Disease.

    PubMed

    Otsuki, Satoru; Nagaoka, Masanori

    2016-01-01

    This study aimed to investigate whether the cognition of spatial distance in reaching movements was decreased in patients with Parkinson's disease (PD) and whether this cognition was associated with various symptoms of PD. Estimated and actual maximal reaching distances were measured in three directions in PD patients and healthy elderly volunteers. Differences between estimated and actual measurements were compared within each group. In the PD patients, the associations between "error in cognition" of reaching distance and "clinical findings" were also examined. The results showed that no differences were observed in any values regardless of dominance of hand and severity of symptoms. The differences between the estimated and actual measurements were negatively deviated in the PD patients, indicating that they tended to underestimate reaching distance. "Error in cognition" of reaching distance correlated with the items of posture in the motor section of the Unified Parkinson's Disease Rating Scale. This suggests that, in PD patients, postural deviation and postural instability might affect the cognition of the distance from a target object.

  16. Social learning across psychological distance.

    PubMed

    Kalkstein, David A; Kleiman, Tali; Wakslak, Cheryl J; Liberman, Nira; Trope, Yaacov

    2016-01-01

    While those we learn from are often close to us, more and more our learning environments are shifting to include more distant and dissimilar others. The question we examine in 5 studies is how whom we learn from influences what we learn and how what we learn influences from whom we choose to learn it. In Study 1, we show that social learning, in and of itself, promotes higher level (more abstract) learning than does learning based on one's own direct experience. In Studies 2 and 3, we show that when people learn from and emulate others, they tend to do so at a higher level when learning from a distant model than from a near model. Studies 4 and 5 show that thinking about learning at a higher (compared to a lower) level leads individuals to expand the range of others that they will consider learning from. Study 6 shows that when given an actual choice, people prefer to learn low-level information from near sources and high-level information from distant sources. These results demonstrate a basic link between level of learning and psychological distance in social learning processes.

  17. Long distance laser communications demonstration

    NASA Astrophysics Data System (ADS)

    Northcott, Malcolm J.; McClaren, A.; Graves, J. E.; Phillips, John; Driver, Don; Abelson, David; Young, David W.; Sluz, Joseph E.; Juarez, Juan C.; Airola, Marc B.; Sova, Raymond M.; Hurt, Harry; Foshee, James

    2007-04-01

    AOptix demonstrated a simulated air-to-air laser communications (laser-com) system over a 147Km distance by establishing a laser communication link between the islands of Hawaii and Maui. We expect the atmospheric conditions encountered during this demonstration to be representative of the worst seeing conditions that could be expected for an actual air to air link. AOptix utilized laser-com terminal incorporating Adaptive Optics (AO) to perform high speed tracking and aberration correction to reduce the effects of the seeing. The demonstration showed the feasibility of establishing high data rate point to point laser-com links between aircraft. In conjunction with Johns Hopkins University Applied Physics Laboratory networking equipment we were able to demonstrate a 40Gbit DWDM link, providing significantly more data throughput than is available using RF technologies. In addition to being very high data rate, the link demonstrates very low beam spread, which gives very high covertness, and a high degree of data security. Since the link is based on 1550nm optical wavelengths it is inherently resistant to jamming.

  18. Deep-Focusing Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Jensen, J. M.; Kosovichev, A. G.; Birch, A. C.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Much progress has been made by measuring the travel times of solar acoustic waves from a central surface location to points at equal arc distance away. Depth information is obtained from the range of arc distances examined, with the larger distances revealing the deeper layers. This method we will call surface-focusing, as the common point, or focus, is at the surface. To obtain a clearer picture of the subsurface region, it would, no doubt, be better to focus on points below the surface. Our first attempt to do this used the ray theory to pick surface location pairs that would focus on a particular subsurface point. This is not the ideal procedure, as Born approximation kernels suggest that this focus should have zero sensitivity to sound speed inhomogeneities. However, the sensitivity is concentrated below the surface in a much better way than the old surface-focusing method, and so we expect the deep-focusing method to be more sensitive. A large sunspot group was studied by both methods. Inversions based on both methods will be compared.

  19. Effect of Geographic Distance on Distance Education: An Empirical Study

    ERIC Educational Resources Information Center

    Luo, Heng; Robinson, Anthony C.; Detwiler, Jim

    2014-01-01

    This study investigates the effect of geographic distance on students' distance learning experience with the aim to provide tentative answers to a fundamental question--does geographic distance matter in distance education? Using educational outcome data collected from an online master's program in Geographic Information Systems, this…

  20. Distance Training as Part of a Distance Consulting Solution.

    ERIC Educational Resources Information Center

    Fulantelli, Giovanni; Chiazzese, Giuseppe; Allegra, Mario

    "Distance Training" models, when integrated in a more complex framework, such as a "Distance Consulting" model, present specific features and impose a revision of the strategies commonly adopted in distance training experiences. This paper reports on the distance training strategies adopted in a European funded project aimed at defining and…

  1. 38 CFR 60.5 - Travel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Travel. 60.5 Section 60.5... TEMPORARY LODGING § 60.5 Travel. As a condition for receiving temporary lodging under this part, a veteran must be required to travel either 50 or more miles, or at least two hours from his or her home to...

  2. 5 CFR 630.207 - Travel time.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Travel time. 630.207 Section 630.207... and General Provisions for Annual and Sick Leave § 630.207 Travel time. The travel time granted an employee under section 6303(d) of title 5, United States Code, is inclusive of the time...

  3. 5 CFR 630.207 - Travel time.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Travel time. 630.207 Section 630.207... and General Provisions for Annual and Sick Leave § 630.207 Travel time. The travel time granted an employee under section 6303(d) of title 5, United States Code, is inclusive of the time...

  4. The Traveler with Sickle Cell Disease

    PubMed Central

    Willen, Shaina M.; Thornburg, Courtney D.; Lantos, Paul M.

    2014-01-01

    Background Sickle cell disease (SCD) is the most common genetic disease among persons with African ancestry. This article provides a background on SCD and reviews many important aspects of travel preparation in this population. Methods The medical literature was searched for studies about travel-associated preparedness and complications in individuals with SCD. Topics researched included malaria, bacterial infections, vaccinations, dehydration, altitude, air travel, and travel preparedness. Results There is very little published literature that specifically addresses the risks faced by travelers with SCD. Rates of medical complications during travel appear to be high. There is a body of literature that describes complications of SCD in indigenous populations, particularly within Africa. The generalizability of these data to a traveler are uncertain. Combining these sources of data and the broader medical literature we address major travel-related questions that may face a provider preparing an individual with SCD for safe travel. Conclusions Travelers with SCD face considerable medical risks when traveling to developing tropical countries; these include malaria, bacterial infections, hypovolemia, and sickle cell-associated vaso-occlusive crises. Frank counseling about risks, vigilant preventative measures, and contingency planning for illness while abroad are necessary parts of the pre-travel visit for individuals with SCD. PMID:24947546

  5. 5 CFR 630.207 - Travel time.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Travel time. 630.207 Section 630.207... and General Provisions for Annual and Sick Leave § 630.207 Travel time. The travel time granted an employee under section 6303(d) of title 5, United States Code, is inclusive of the time...

  6. 5 CFR 630.207 - Travel time.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Travel time. 630.207 Section 630.207... and General Provisions for Annual and Sick Leave § 630.207 Travel time. The travel time granted an employee under section 6303(d) of title 5, United States Code, is inclusive of the time...

  7. 5 CFR 630.207 - Travel time.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Travel time. 630.207 Section 630.207... and General Provisions for Annual and Sick Leave § 630.207 Travel time. The travel time granted an employee under section 6303(d) of title 5, United States Code, is inclusive of the time...

  8. 32 CFR 726.6 - Travel orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Travel orders. 726.6 Section 726.6 National... MENTALLY INCOMPETENT MEMBERS OF THE NAVAL SERVICE § 726.6 Travel orders. The Chief of Naval Personnel or the Deputy Commandant, Manpower & Reserve Affairs, may issue travel orders to a member to...

  9. 38 CFR 21.3105 - Travel expenses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Travel expenses. 21.3105.... Chapter 35 Counseling § 21.3105 Travel expenses. (a) General. VA shall determine and pay the necessary expense of travel to and from the place of counseling for an eligible person who is required to...

  10. 28 CFR 2.41 - Travel approval.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Travel approval. 2.41 Section 2.41..., YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.41 Travel approval. (a) The probation officer may approve travel outside the district without approval of...

  11. 38 CFR 60.5 - Travel.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Travel. 60.5 Section 60.5... TEMPORARY LODGING § 60.5 Travel. As a condition for receiving temporary lodging under this part, a veteran must be required to travel either 50 or more miles, or at least two hours from his or her home to...

  12. 32 CFR 726.6 - Travel orders.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Travel orders. 726.6 Section 726.6 National... MENTALLY INCOMPETENT MEMBERS OF THE NAVAL SERVICE § 726.6 Travel orders. The Chief of Naval Personnel or the Deputy Commandant, Manpower & Reserve Affairs, may issue travel orders to a member to...

  13. 38 CFR 21.3105 - Travel expenses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Travel expenses. 21.3105.... Chapter 35 Counseling § 21.3105 Travel expenses. (a) General. VA shall determine and pay the necessary expense of travel to and from the place of counseling for an eligible person who is required to...

  14. 20 CFR 617.46 - Travel allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... mile at the prevailing mileage rate authorized under the Federal travel regulations (see 41 CFR part... prevailing per diem allowance rate authorized under the Federal travel regulations (see 41 CFR part 101-7... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Travel allowance. 617.46 Section...

  15. Acute Chagas Disease in a Returning Traveler

    PubMed Central

    Carter, Yvonne L.; Juliano, Jonathan J.; Montgomery, Susan P.; Qvarnstrom, Yvonne

    2012-01-01

    Acute Chagas disease is rarely recognized, and the risk for acquiring the disease is undefined in travelers to Central America. We describe a case of acute Chagas disease in a traveler to Costa Rica and highlight the need for increased awareness of this infection in travelers to Chagas-endemic areas. PMID:23091192

  16. Time-distance helioseismology of two realistic sunspot simulations

    SciTech Connect

    DeGrave, K.; Jackiewicz, J.; Rempel, M. E-mail: jasonj@nmsu.edu

    2014-10-10

    Linear time-distance helioseismic inversions are carried out using several filtering schemes to determine vector flow velocities within two ∼100{sup 2} Mm{sup 2} × 20 Mm realistic magnetohydrodynamic sunspot simulations of 25 hr. One simulation domain contains a model of a full sunspot (i.e., one with both an umbra and penumbra), while the other contains a pore (i.e., a spot without a penumbra). The goal is to test current helioseismic methods using these state-of-the-art simulations of magnetic structures. We find that horizontal flow correlations between inversion and simulation flow maps are reasonably high (∼0.5-0.8) in the upper 3 Mm at distances exceeding 25-30 Mm from spot center, but are substantially lower at smaller distances and larger depths. Inversions of forward-modeled travel times consistently outperform those of our measured travel times in terms of horizontal flow correlations, suggesting that our inability to recover flow structure near these active regions is largely due to the fact that we are unable to accurately measure travel times near strong magnetic features. In many cases the velocity amplitudes from the inversions underestimate those of the simulations by up to 50%, possibly indicating nonlinearity of the forward problem. In every case, we find that our inversions are unable to recover the vertical flow structure of the simulations at any depth.

  17. Distance Measurement Solves Astrophysical Mysteries

    NASA Astrophysics Data System (ADS)

    2003-08-01

    distance. "Our measurements showed that the pulsar is about 950 light-years from Earth, essentially the same distance as the supernova remnant," said Steve Thorsett, of the University of California, Santa Cruz. "That means that the two almost certainly were created by the same supernova blast," he added. With that problem solved. the astronomers then turned to studying the pulsar's neutron star itself. Using a variety of data from different telescopes and armed with the new distance measurement, they determined that the neutron star is between 16 and 25 miles in diameter. In such a small size, it packs a mass roughly equal to that of the Sun. The next result of learning the pulsar's actual distance was to provide a possible answer to a longstanding question about cosmic rays. Cosmic rays are subatomic particles or atomic nuclei accelerated to nearly the speed of light. Shock waves in supernova remnants are thought to be responsible for accelerating many of these particles. Scientists can measure the energy of cosmic rays, and had noted an excess of such rays in a specific energy range. Some researchers had suggested that the excess could come from a single supernova remnant about 1000 light-years away whose supernova explosion was about 100,000 years ago. The principal difficulty with this suggestion was that there was no accepted candidate for such a source. "Our measurement now puts PSR B0656+14 and the Monogem Ring at exactly the right place and at exactly the right age to be the source of this excess of cosmic rays," Brisken said. With the ability of the VLBA, one of the telescopes of the NRAO, to make extremely precise position measurements, the astronomers expect to improve the accuracy of their distance determination even more. "This pulsar is becoming a fascinating laboratory for studying astrophysics and nuclear physics," Thorsett said. In addition to Brisken and Thorsett, the team of astronomers includes Aaron Golden of the National University of Ireland, Robert

  18. 76 FR 79226 - Travelers Insurance, a Subsidiary of the Travelers Indemnity Company, Personal Insurance Division...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-21

    ... included workers and former workers of The Travelers Indemnity Company, a wholly-owned subsidiary of The... Employment and Training Administration Travelers Insurance, a Subsidiary of the Travelers Indemnity Company... response to a petition filed on May 4, 2011 on behalf of workers of Travelers Insurance, a subsidiary...

  19. 78 FR 73702 - Federal Travel Regulation (FTR); Telework Travel Expenses Test Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...] RIN 3090-AJ23 Federal Travel Regulation (FTR); Telework Travel Expenses Test Programs AGENCY: Office... 2010, which establishes and authorizes telework travel expenses test programs, authorizes reimbursement for any necessary travel expenses in conjunction with such a test program in lieu of any...

  20. Plasma Colloquium Travel Grant Program

    SciTech Connect

    Hazeltine, R.D.

    1998-09-14

    OAK B188 Plasma Colloquium Travel Grant Program. The purpose of the Travel Grant Program is to increase the awareness of plasma research. The new results and techniques of plasma research in fusion plasmas, plasma processing space plasmas, basic plasma science, etc, have broad applicability throughout science. The benefits of these results are limited by the relatively low awareness and appreciation of plasma research in the larger scientific community. Whereas spontaneous interactions between plasma scientists and other scientists are useful, a focused effort in education and outreach to other scientists is efficient and is needed. The academic scientific community is the initial focus of this effort, since that permits access to a broad cross-section of scientists and future scientists including undergraduates, graduate students, faculty, and research staff.

  1. Respiratory infections during air travel.

    PubMed

    Leder, K; Newman, D

    2005-01-01

    An increasing number of individuals undertake air travel annually. Issues regarding cabin air quality and the potential risks of transmission of respiratory infections during flight have been investigated and debated previously, but, with the advent of severe acute respiratory syndrome and influenza outbreaks, these issues have recently taken on heightened importance. Anecdotally, many people complain of respiratory symptoms following air travel. However, studies of ventilation systems and patient outcomes indicate the spread of pathogens during flight occurs rarely. In the present review, aspects of the aircraft cabin environment that affect the likelihood of transmission of respiratory pathogens on airplanes are outlined briefly and evidence for the occurrence of outbreaks of respiratory illness among airline passengers are reviewed.

  2. Aggregate vehicle travel forecasting model

    SciTech Connect

    Greene, D.L.; Chin, Shih-Miao; Gibson, R.

    1995-05-01

    This report describes a model for forecasting total US highway travel by all vehicle types, and its implementation in the form of a personal computer program. The model comprises a short-run, econometrically-based module for forecasting through the year 2000, as well as a structural, scenario-based longer term module for forecasting through 2030. The short-term module is driven primarily by economic variables. It includes a detailed vehicle stock model and permits the estimation of fuel use as well as vehicle travel. The longer-tenn module depends on demographic factors to a greater extent, but also on trends in key parameters such as vehicle load factors, and the dematerialization of GNP. Both passenger and freight vehicle movements are accounted for in both modules. The model has been implemented as a compiled program in the Fox-Pro database management system operating in the Windows environment.

  3. Air resistance measurements on actual airplane parts

    NASA Technical Reports Server (NTRS)

    Weiselsberger, C

    1923-01-01

    For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine.

  4. Explosive Percolation Transition is Actually Continuous

    NASA Astrophysics Data System (ADS)

    da Costa, R. A.; Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.

    2010-12-01

    Recently a discontinuous percolation transition was reported in a new “explosive percolation” problem for irreversible systems [D. Achlioptas, R. M. D’Souza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

  5. Analysis of plug-in hybrid electric vehicles' utility factors using GPS-based longitudinal travel data

    DOE PAGES

    Wu, Xing; Aviquzzaman, Md.; Lin, Zhenhong

    2015-05-29

    The benefit of using a PHEV comes from its ability to substitute gasoline with electricity in operation. Defined as the proportion of distance traveled in the electric mode, the utility factor (UF) depends mostly on the battery capacity, but also on many other factors, such as travel pattern and recharging pattern. Conventionally, the UFs are calculated based on the daily vehicle miles traveled (DVMT) by assuming motorists leave home in the morning with a full battery, and no charge occurs before returning home in the evening. Such an assumption, however, ignores the impact of the heterogeneity in both travel andmore » charging behavior, such as going back home more than once in a day, the impact of available charging time, and the price of gasoline. In addition, the conventional UFs are based on the National Household Travel Survey (NHTS) data, which are one-day travel data of each sample vehicle. A motorist's daily distance variation is ignored. This paper employs the GPS-based longitudinal travel data (covering 3-18 months) collected from 403 vehicles in the Seattle metropolitan area to investigate how such travel and charging behavior affects UFs. To do this, for each vehicle, we organized trips to a series of home and work related tours. The UFs based on the DVMT are found close to those based on home-to-home tours. However, it is seen that the workplace charge opportunities significantly increase UFs if the CD range is no more than 40 miles.« less

  6. Analysis of plug-in hybrid electric vehicles' utility factors using GPS-based longitudinal travel data

    SciTech Connect

    Wu, Xing; Aviquzzaman, Md.; Lin, Zhenhong

    2015-05-29

    The benefit of using a PHEV comes from its ability to substitute gasoline with electricity in operation. Defined as the proportion of distance traveled in the electric mode, the utility factor (UF) depends mostly on the battery capacity, but also on many other factors, such as travel pattern and recharging pattern. Conventionally, the UFs are calculated based on the daily vehicle miles traveled (DVMT) by assuming motorists leave home in the morning with a full battery, and no charge occurs before returning home in the evening. Such an assumption, however, ignores the impact of the heterogeneity in both travel and charging behavior, such as going back home more than once in a day, the impact of available charging time, and the price of gasoline. In addition, the conventional UFs are based on the National Household Travel Survey (NHTS) data, which are one-day travel data of each sample vehicle. A motorist's daily distance variation is ignored. This paper employs the GPS-based longitudinal travel data (covering 3-18 months) collected from 403 vehicles in the Seattle metropolitan area to investigate how such travel and charging behavior affects UFs. To do this, for each vehicle, we organized trips to a series of home and work related tours. The UFs based on the DVMT are found close to those based on home-to-home tours. However, it is seen that the workplace charge opportunities significantly increase UFs if the CD range is no more than 40 miles.

  7. Treating time travel quantum mechanically

    NASA Astrophysics Data System (ADS)

    Allen, John-Mark A.

    2014-10-01

    The fact that closed timelike curves (CTCs) are permitted by general relativity raises the question as to how quantum systems behave when time travel to the past occurs. Research into answering this question by utilizing the quantum circuit formalism has given rise to two theories: Deutschian-CTCs (D-CTCs) and "postselected" CTCs (P-CTCs). In this paper the quantum circuit approach is thoroughly reviewed, and the strengths and shortcomings of D-CTCs and P-CTCs are presented in view of their nonlinearity and time-travel paradoxes. In particular, the "equivalent circuit model"—which aims to make equivalent predictions to D-CTCs, while avoiding some of the difficulties of the original theory—is shown to contain errors. The discussion of D-CTCs and P-CTCs is used to motivate an analysis of the features one might require of a theory of quantum time travel, following which two overlapping classes of alternate theories are identified. One such theory, the theory of "transition probability" CTCs (T-CTCs), is fully developed. The theory of T-CTCs is shown not to have certain undesirable features—such as time-travel paradoxes, the ability to distinguish nonorthogonal states with certainty, and the ability to clone or delete arbitrary pure states—that are present with D-CTCs and P-CTCs. The problems with nonlinear extensions to quantum mechanics are discussed in relation to the interpretation of these theories, and the physical motivations of all three theories are discussed and compared.

  8. HELIOSEISMIC SIGNATURE OF CHROMOSPHERIC DOWNFLOWS IN ACOUSTIC TRAVEL-TIME MEASUREMENTS FROM HINODE

    SciTech Connect

    Nagashima, Kaori; Sekii, Takashi; Kosovichev, Alexander G.; Zhao Junwei; Tarbell, Theodore D.

    2009-04-01

    We report on a signature of chromospheric downflows in two emerging flux regions detected by time-distance helioseismology analysis. We use both chromospheric intensity oscillation data in the Ca II H line and photospheric Dopplergrams in the Fe I 557.6 nm line obtained by Hinode/SOT for our analyses. By cross-correlating the Ca II oscillation signals, we have detected a travel-time anomaly in the plage regions; outward travel times are shorter than inward travel times by 0.5-1 minute. However, such an anomaly is absent in the Fe I data. These results can be interpreted as evidence of downflows in the lower chromosphere. The downflow speed is estimated to be below 10 km s{sup -1}. This result demonstrates a new possibility of studying chromospheric flows by time-distance analysis.

  9. Correlation of ideal and actual shear strengths of metals with their friction properties

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1981-01-01

    The relation between the ideal and actual shear strengths and friction properties of clean metals in contact with clean diamond, boron nitride, silicon carbide, manganese-zinc ferrite, and the metals themselves in vacuum is discussed. An estimate of the ideal shear strength for metals is obtained from the shear modulus, the repeat distance of atoms in the direction of shear of the metal, and the interplanar spacing of the shearing planes. The coefficient of friction for metals is shown to be correlated with both the ideal and actual shear strength of metals. The higher the strength of the metal, the lower the coefficient of friction occurs.

  10. Measuring Astronomical Distances with Linear Programming

    NASA Astrophysics Data System (ADS)

    Narain, Akshar

    2015-05-01

    A few years ago it was suggested that the distance to celestial bodies could be computed by tracking their position over about 24 hours and then solving a regression problem. One only needed to use inexpensive telescopes, cameras, and astrometry tools, and the experiment could be done from one's backyard. However, it is not obvious to an amateur what the regression problem is and how to solve it. This paper identifies that problem and shows how to solve it with linear programming. It also takes into account the body's celestial latitude to improve the method's accuracy. The new method is validated both with simulated and actual data to compute distances to asteroids to within 1% of correct values. It can be used as a new tutorial for amateurs to see how consumer-grade astrophotography and free astrometry and optimization tools come together to solve an important problem. It can also be used as a tool in crowdsourced detection of dangerous asteroids.

  11. Interpersonal distance modeling during fighting activities.

    PubMed

    Dietrich, Gilles; Bredin, Jonathan; Kerlirzin, Yves

    2010-10-01

    The aim of this article is to elaborate a general framework for modeling dual opposition activities, or more generally, dual interaction. The main hypothesis is that opposition behavior can be measured directly from a global variable and that the relative distance between the two subjects can be this parameter. Moreover, this parameter should be considered as multidimensional parameter depending not only on the dynamics of the subjects but also on the "internal" parameters of the subjects, such as sociological and/or emotional states. Standard and simple mechanical formalization will be used to model this multifactorial distance. To illustrate such a general modeling methodology, this model was compared with actual data from an opposition activity like Japanese fencing (kendo). This model captures not only coupled coordination, but more generally interaction in two-subject activities. PMID:21051791

  12. International travel and HIV infection.

    PubMed Central

    von Reyn, C. F.; Mann, J. M.; Chin, J.

    1990-01-01

    Although human immunodeficiency virus (HIV) infection is a worldwide problem, its prevalence and pattern vary from country to country. Accordingly, the risk to international travellers of acquiring HIV infection also varies widely in different parts of the world, and depends principally on their behaviour. The risk of sexual acquisition of HIV infection can be virtually eliminated by avoiding penetrative sexual intercourse with intravenous drug users and persons who have had multiple sexual partners (such as prostitutes) or reduced by the use of condoms. The risk of parenteral exposure to HIV can be reduced by avoiding parenteral drug use and behaviour that is likely to lead to injury (with its attendant risk of requiring blood transfusion) and by seeking medical facilities with adequate capabilities to screen blood donors for HIV and to sterilize instruments. HIV screening of international travellers is an ineffective, costly, and impractical public health strategy for limiting the worldwide spread of HIV infection. Travellers infected with HIV require specialized advice regarding health precautions, prophylactic medications, and immunization. PMID:2194689

  13. Traveling-wave induction launchers

    NASA Technical Reports Server (NTRS)

    Elliott, David G.

    1989-01-01

    An analysis of traveling-wave induction launchers shows that induction is a feasible method of producing armature current and that efficient accelerators can be built without sliding contacts or arcs. In a traveling-wave induction launcher the armature current is induced by a slip speed between the armature and a traveling magnetic field. At 9 m/s slip speed a 9 kg projectile with an aluminum armature weighing 25 percent of the total mass can be accelerated to 3000 m/s in a 5 m-long barrel with a total ohmic loss in the barrel coils and armature of 4 percent of the launch kinetic energy and with an average armature temperature rise of 220 deg C, but a peak excitation frequency of 8600 Hz is required. With a 2 kg launch mass the ohmic loss is 7 percent. A launcher system optimized for rotating generators would have a peak frequency of 4850 Hz; with an aluminum armature weighing 33 percent of the launch mass and a slip speed of 30 m/s the total ohmic loss in the generators, cables, and accelerator would be 43 percent of the launch kinetic energy, and the average armature temperature rise would be 510 deg C.

  14. Infectious Risks of Air Travel.

    PubMed

    Mangili, Alexandra; Vindenes, Tine; Gendreau, Mark

    2015-10-01

    Infectious diseases are still among the leading causes of death worldwide due to their persistence, emergence, and reemergence. As the recent Ebola virus disease and MERS-CoV outbreaks demonstrate, the modern epidemics and large-scale infectious outbreaks emerge and spread quickly. Air transportation is a major vehicle for the rapid spread and dissemination of communicable diseases, and there have been a number of reported outbreaks of serious airborne diseases aboard commercial flights including tuberculosis, severe acute respiratory syndrome, influenza, smallpox, and measles, to name a few. In 2014 alone, over 3.3 billion passengers (a number equivalent to 42% of the world population) and 50 million metric tons of cargo traveled by air from 41,000 airports and 50,000 routes worldwide, and significant growth is anticipated, with passenger numbers expected to reach 5.9 billion by 2030. Given the increasing numbers of travelers, the risk of infectious disease transmission during air travel is a significant concern, and this chapter focuses on the current knowledge about transmission of infectious diseases in the context of both transmissions within the aircraft passenger cabin and commercial aircraft serving as vehicles of worldwide infection spread. PMID:26542037

  15. Infectious Risks of Air Travel.

    PubMed

    Mangili, Alexandra; Vindenes, Tine; Gendreau, Mark

    2015-10-01

    Infectious diseases are still among the leading causes of death worldwide due to their persistence, emergence, and reemergence. As the recent Ebola virus disease and MERS-CoV outbreaks demonstrate, the modern epidemics and large-scale infectious outbreaks emerge and spread quickly. Air transportation is a major vehicle for the rapid spread and dissemination of communicable diseases, and there have been a number of reported outbreaks of serious airborne diseases aboard commercial flights including tuberculosis, severe acute respiratory syndrome, influenza, smallpox, and measles, to name a few. In 2014 alone, over 3.3 billion passengers (a number equivalent to 42% of the world population) and 50 million metric tons of cargo traveled by air from 41,000 airports and 50,000 routes worldwide, and significant growth is anticipated, with passenger numbers expected to reach 5.9 billion by 2030. Given the increasing numbers of travelers, the risk of infectious disease transmission during air travel is a significant concern, and this chapter focuses on the current knowledge about transmission of infectious diseases in the context of both transmissions within the aircraft passenger cabin and commercial aircraft serving as vehicles of worldwide infection spread.

  16. Air travel and venous thromboembolism.

    PubMed Central

    Mendis, Shanthi; Yach, Derek; Alwan, Ala

    2002-01-01

    There has recently been increased publicity on the risk of venous thrombosis after long-haul flights. This paper reviews the evidence base related to the association between air travel and venous thromboembolism. The evidence consists only of case reports, clinical case-control studies and observational studies involving the use of intermediate end-points, or expert opinion. Some studies have suggested that there is no clear association, whereas others have indicated a strong relationship. On the whole it appears that there is probably a link between air travel and venous thrombosis. However, the link is likely to be weak, mainly affecting passengers with additional risk factors for venous thromboembolism. The available evidence is not adequate to allow quantification of the risk. There are insufficient scientific data on which to base specific recommendations for prevention, other than that leg exercise should be taken during travel. Further studies are urgently needed in order to identify prospectively the incidence of the condition and those at risk. PMID:12077617

  17. Twitter for travel medicine providers.

    PubMed

    Mills, Deborah J; Kohl, Sarah E

    2016-03-01

    Travel medicine practitioners, perhaps more so than medical practitioners working in other areas of medicine, require a constant flow of information to stay up-to-date, and provide best practice information and care to their patients. Many travel medicine providers are unaware of the popularity and potential of the Twitter platform. Twitter use among our travellers, as well as by physicians and health providers, is growing exponentially. There is a rapidly expanding body of published literature on this information tool. This review provides a brief overview of the ways Twitter is being used by health practitioners, the advantages that are peculiar to Twitter as a platform of social media, and how the interested practitioner can get started. Some key points about the dark side of Twitter are highlighted, as well as the potential benefits of using Twitter as a way to disseminate accurate medical information to the public. This article will help readers develop an increased understanding of Twitter as a tool for extracting useful facts and insights from the ever increasing volume of health information.

  18. Twitter for travel medicine providers.

    PubMed

    Mills, Deborah J; Kohl, Sarah E

    2016-03-01

    Travel medicine practitioners, perhaps more so than medical practitioners working in other areas of medicine, require a constant flow of information to stay up-to-date, and provide best practice information and care to their patients. Many travel medicine providers are unaware of the popularity and potential of the Twitter platform. Twitter use among our travellers, as well as by physicians and health providers, is growing exponentially. There is a rapidly expanding body of published literature on this information tool. This review provides a brief overview of the ways Twitter is being used by health practitioners, the advantages that are peculiar to Twitter as a platform of social media, and how the interested practitioner can get started. Some key points about the dark side of Twitter are highlighted, as well as the potential benefits of using Twitter as a way to disseminate accurate medical information to the public. This article will help readers develop an increased understanding of Twitter as a tool for extracting useful facts and insights from the ever increasing volume of health information. PMID:26988200

  19. The Economic Importance of Air Travel in High-Amenity Rural Areas

    ERIC Educational Resources Information Center

    Rasker, Ray; Gude, Patricia H.; Gude, Justin A.; van den Noort, Jeff

    2009-01-01

    The western United States offers a case study on the importance of access to large population centers and their markets, via road and air travel, for economic development. The vast distances between towns and cities in the American West can be a detriment to business, yet they also serve to attract technology and knowledge-based workers seeking to…

  20. The Effect of Increased Travel Reimbursement Rates on Health Care Utilization in the VA

    ERIC Educational Resources Information Center

    Nelson, Richard E.; Hicken, Bret; West, Alan; Rupper, Randall

    2012-01-01

    Purpose: The reimbursement rate that eligible veterans receive for travel to Department of Veterans Affairs (VA) facilities increased from 11 to 28.5 cents per mile on February 1, 2008. We examined the effect of this policy change on utilization of outpatient, inpatient, and pharmacy services, stratifying veterans based on distance from a VA…