The significance of direct sunlight and polarized skylight in the ant’s celestial system of navigation

PubMed Central

Wehner, Rüdiger; Müller, Martin

2006-01-01

As textbook knowledge has it, bees and ants use polarized skylight as a backup cue whenever the main compass cue, the sun, is obscured by clouds. Here we show, by employing a unique experimental paradigm, that the celestial compass system of desert ants, Cataglyphis, relies predominantly on polarized skylight. If ants experience only parts of the polarization pattern during training but the full pattern in a subsequent test situation, they systematically deviate from their true homeward courses, with the systematics depending on what parts of the skylight patterns have been presented during training. This “signature” of the polarization compass remains unaltered, even if the ants can simultaneously experience the sun, which, if presented alone, enables the ants to select their true homeward courses. Information provided by direct sunlight and polarized skylight is picked up by different parts of the ant’s compound eyes and is channeled into two rather separate systems of navigation. PMID:16888039

Accuracy of sun localization in the second step of sky-polarimetric Viking navigation for north determination: a planetarium experiment.

PubMed

Farkas, Alexandra; Száz, Dénes; Egri, Ádám; Blahó, Miklós; Barta, András; Nehéz, Dóra; Bernáth, Balázs; Horváth, Gábor

2014-07-01

It is a widely discussed hypothesis that Viking seafarers might have been able to locate the position of the occluded sun by means of dichroic or birefringent crystals, the mysterious sunstones, with which they could analyze skylight polarization. Although the atmospheric optical prerequisites and certain aspects of the efficiency of this sky-polarimetric Viking navigation have been investigated, the accuracy of the main steps of this method has not been quantitatively examined. To fill in this gap, we present here the results of a planetarium experiment in which we measured the azimuth and elevation errors of localization of the invisible sun. In the planetarium sun localization was performed in two selected celestial points on the basis of the alignments of two small sections of two celestial great circles passing through the sun. In the second step of sky-polarimetric Viking navigation the navigator needed to determine the intersection of two such celestial circles. We found that the position of the sun (solar elevation θ(S), solar azimuth φ(S)) was estimated with an average error of +0.6°≤Δθ≤+8.8° and -3.9°≤Δφ≤+2.0°. We also calculated the compass direction error when the estimated sun position is used for orienting with a Viking sun-compass. The northern direction (ω(North)) was determined with an error of -3.34°≤Δω(North)≤+6.29°. The inaccuracy of the second step of this navigation method was high (Δω(North)=-16.3°) when the solar elevation was 5°≤θ(S)≤25°, and the two selected celestial points were far from the sun (at angular distances 95°≤γ(1), γ(2)≤115°) and each other (125°≤δ≤145°). Considering only this second step, the sky-polarimetric navigation could be more accurate in the mid-summer period (June and July), when in the daytime the sun is high above the horizon for long periods. In the spring (and autumn) equinoctial period, alternative methods (using a twilight board, for example) might be more appropriate. Since Viking navigators surely also committed further errors in the first and third steps, the orientation errors presented here underestimate the net error of the whole sky-polarimetric navigation.

Do neotropical migrant butterflies navigate using a solar compass?

PubMed

Oliveira; Srygley; Dudley

1998-12-01

Many tropical butterfly species are well-known for their migratory behaviour. Although these insects can maintain a constant direction throughout the day, the physiological mechanisms of orientation are unknown. It has been argued that tropical migrant butterflies must use a time-compensated sun compass to accomplish their journey, but the crucial experimental manipulations to test this hypothesis have not been conducted. This study reports the results of clock-shift experiments performed with two species of migrating butterflies (Pieridae: Aphrissa statira and Phoebis argante) captured during flight across Lake Gatun, Panama. The observed constant flight bearing of natural controls suggests that these species are capable of performing time-compensated celestial navigation. Our clock-shift experiments suggest that a sun compass is involved. Individuals submitted to a 4 h advance shift took significantly different mean orientations on release compared with control butterflies. The direction of this difference was consistent with the use of a sun compass. The magnitude was approximately half the predicted value if the vanishing bearing of released butterflies was used as the variable to evaluate the effect of time-shifting and approximately three-quarters of that predicted if the estimated heading was the variable used. Mean vanishing bearings of control and experimental butterflies did not correspond to predicted values. This difference can be attributed largely to the combined effects of wind and handling.

Interactions of the polarization and the sun compass in path integration of desert ants.

PubMed

Lebhardt, Fleur; Ronacher, Bernhard

2014-08-01

Desert ants, Cataglyphis fortis, perform large-scale foraging trips in their featureless habitat using path integration as their main navigation tool. To determine their walking direction they use primarily celestial cues, the sky's polarization pattern and the sun position. To examine the relative importance of these two celestial cues, we performed cue conflict experiments. We manipulated the polarization pattern experienced by the ants during their outbound foraging excursions, reducing it to a single electric field (e-)vector direction with a linear polarization filter. The simultaneous view of the sun created situations in which the directional information of the sun and the polarization compass disagreed. The heading directions of the homebound runs recorded on a test field with full view of the natural sky demonstrate that none of both compasses completely dominated over the other. Rather the ants seemed to compute an intermediate homing direction to which both compass systems contributed roughly equally. Direct sunlight and polarized light are detected in different regions of the ant's compound eye, suggesting two separate pathways for obtaining directional information. In the experimental paradigm applied here, these two pathways seem to feed into the path integrator with similar weights.

Animal behaviour: geomagnetic map used in sea-turtle navigation.

PubMed

Lohmann, Kenneth J; Lohmann, Catherine M F; Ehrhart, Llewellyn M; Bagley, Dean A; Swing, Timothy

2004-04-29

Migratory animals capable of navigating to a specific destination, and of compensating for an artificial displacement into unfamiliar territory, are thought to have a compass for maintaining their direction of travel and a map sense that enables them to know their location relative to their destination. Compasses are based on environmental cues such as the stars, the Sun, skylight polarization and magnetism, but little is known about the sensory mechanism responsible for the map sense. Here we show that the green sea-turtle (Chelonia mydas) has a map that is at least partly based on geomagnetic cues.

A magnetic compass aids monarch butterfly migration

PubMed Central

Guerra, Patrick A; Gegear, Robert J; Reppert, Steven M

2014-01-01

Convincing evidence that migrant monarch butterflies (Danaus plexippus) use a magnetic compass to aid their fall migration has been lacking from the spectacular navigational capabilities of this species. Here we use flight simulator studies to show that migrants indeed possess an inclination magnetic compass to help direct their flight equatorward in the fall. The use of this inclination compass is light-dependent utilizing ultraviolet-A/blue light between 380 and 420 nm. Notably, the significance of light <420 nm for inclination compass function was not considered in previous monarch studies. The antennae are important for the inclination compass because they appear to contain light-sensitive magnetosensors. For migratory monarchs, the inclination compass may serve as an important orientation mechanism when directional daylight cues are unavailable and may also augment time-compensated sun compass orientation for appropriate directionality throughout the migration. PMID:24960099

Way-finding in displaced clock-shifted bees proves bees use a cognitive map.

PubMed

Cheeseman, James F; Millar, Craig D; Greggers, Uwe; Lehmann, Konstantin; Pawley, Matthew D M; Gallistel, Charles R; Warman, Guy R; Menzel, Randolf

2014-06-17

Mammals navigate by means of a metric cognitive map. Insects, most notably bees and ants, are also impressive navigators. The question whether they, too, have a metric cognitive map is important to cognitive science and neuroscience. Experimentally captured and displaced bees often depart from the release site in the compass direction they were bent on before their capture, even though this no longer heads them toward their goal. When they discover their error, however, the bees set off more or less directly toward their goal. This ability to orient toward a goal from an arbitrary point in the familiar environment is evidence that they have an integrated metric map of the experienced environment. We report a test of an alternative hypothesis, which is that all the bees have in memory is a collection of snapshots that enable them to recognize different landmarks and, associated with each such snapshot, a sun-compass-referenced home vector derived from dead reckoning done before and after previous visits to the landmark. We show that a large shift in the sun-compass rapidly induced by general anesthesia does not alter the accuracy or speed of the homeward-oriented flight made after the bees discover the error in their initial postrelease flight. This result rules out the sun-referenced home-vector hypothesis, further strengthening the now extensive evidence for a metric cognitive map in bees.

Central neural coding of sky polarization in insects.

PubMed

Homberg, Uwe; Heinze, Stanley; Pfeiffer, Keram; Kinoshita, Michiyo; el Jundi, Basil

2011-03-12

Many animals rely on a sun compass for spatial orientation and long-range navigation. In addition to the Sun, insects also exploit the polarization pattern and chromatic gradient of the sky for estimating navigational directions. Analysis of polarization-vision pathways in locusts and crickets has shed first light on brain areas involved in sky compass orientation. Detection of sky polarization relies on specialized photoreceptor cells in a small dorsal rim area of the compound eye. Brain areas involved in polarization processing include parts of the lamina, medulla and lobula of the optic lobe and, in the central brain, the anterior optic tubercle, the lateral accessory lobe and the central complex. In the optic lobe, polarization sensitivity and contrast are enhanced through convergence and opponency. In the anterior optic tubercle, polarized-light signals are integrated with information on the chromatic contrast of the sky. Tubercle neurons combine responses to the UV/green contrast and e-vector orientation of the sky and compensate for diurnal changes of the celestial polarization pattern associated with changes in solar elevation. In the central complex, a topographic representation of e-vector tunings underlies the columnar organization and suggests that this brain area serves as an internal compass coding for spatial directions.

Central neural coding of sky polarization in insects

PubMed Central

Homberg, Uwe; Heinze, Stanley; Pfeiffer, Keram; Kinoshita, Michiyo; el Jundi, Basil

2011-01-01

Many animals rely on a sun compass for spatial orientation and long-range navigation. In addition to the Sun, insects also exploit the polarization pattern and chromatic gradient of the sky for estimating navigational directions. Analysis of polarization–vision pathways in locusts and crickets has shed first light on brain areas involved in sky compass orientation. Detection of sky polarization relies on specialized photoreceptor cells in a small dorsal rim area of the compound eye. Brain areas involved in polarization processing include parts of the lamina, medulla and lobula of the optic lobe and, in the central brain, the anterior optic tubercle, the lateral accessory lobe and the central complex. In the optic lobe, polarization sensitivity and contrast are enhanced through convergence and opponency. In the anterior optic tubercle, polarized-light signals are integrated with information on the chromatic contrast of the sky. Tubercle neurons combine responses to the UV/green contrast and e-vector orientation of the sky and compensate for diurnal changes of the celestial polarization pattern associated with changes in solar elevation. In the central complex, a topographic representation of e-vector tunings underlies the columnar organization and suggests that this brain area serves as an internal compass coding for spatial directions. PMID:21282171

Reviving a neglected celestial underwater polarization compass for aquatic animals.

PubMed

Waterman, Talbot H

2006-02-01

Substantial in situ measurements on clear days in a variety of marine environments at depths in the water down to 200 m have demonstrated the ubiquitous daytime presence of sun-related e-vector (=plane of polarization) patterns. In most lines of sight the e-vectors tilt from horizontal towards the sun at angles equal to the apparent underwater refracted zenith angle of the sun. A maximum tilt-angle of approximately 48.5 degrees , is reached in horizontal lines of sight at 90 degrees to the sun's bearing (the plane of incidence). This tilt limit is set by Snell's window, when the sun is on the horizon. The biological literature since the 1980s has been pervaded with assumptions that daytime aquatic e-vectors are mainly horizontal. This review attempts to set the record straight concerning the potential use of underwater e-vectors as a visual compass and to reopen the field to productive research on aquatic animals' orientation and navigation.

The depth of the honeybee's backup sun-compass systems.

PubMed

Dovey, Katelyn M; Kemfort, Jordan R; Towne, William F

2013-06-01

Honeybees have at least three compass mechanisms: a magnetic compass; a celestial or sun compass, based on the daily rotation of the sun and sun-linked skylight patterns; and a backup celestial compass based on a memory of the sun's movements over time in relation to the landscape. The interactions of these compass systems have yet to be fully elucidated, but the celestial compass is primary in most contexts, the magnetic compass is a backup in certain contexts, and the bees' memory of the sun's course in relation to the landscape is a backup system for cloudy days. Here we ask whether bees have any further compass systems, for example a memory of the sun's movements over time in relation to the magnetic field. To test this, we challenged bees to locate the sun when their known celestial compass systems were unavailable, that is, under overcast skies in unfamiliar landscapes. We measured the bees' knowledge of the sun's location by observing their waggle dances, by which foragers indicate the directions toward food sources in relation to the sun's compass bearing. We found that bees have no celestial compass systems beyond those already known: under overcast skies in unfamiliar landscapes, bees attempt to use their landscape-based backup system to locate the sun, matching the landscapes or skylines at the test sites with those at their natal sites as best they can, even if the matches are poor and yield weak or inconsistent orientation.

Ocelli contribute to the encoding of celestial compass information in the Australian desert ant Melophorus bagoti.

PubMed

Schwarz, Sebastian; Albert, Laurence; Wystrach, Antoine; Cheng, Ken

2011-03-15

Many animal species, including some social hymenoptera, use the visual system for navigation. Although the insect compound eyes have been well studied, less is known about the second visual system in some insects, the ocelli. Here we demonstrate navigational functions of the ocelli in the visually guided Australian desert ant Melophorus bagoti. These ants are known to rely on both visual landmark learning and path integration. We conducted experiments to reveal the role of ocelli in the perception and use of celestial compass information and landmark guidance. Ants with directional information from their path integration system were tested with covered compound eyes and open ocelli on an unfamiliar test field where only celestial compass cues were available for homing. These full-vector ants, using only their ocelli for visual information, oriented significantly towards the fictive nest on the test field, indicating the use of celestial compass information that is presumably based on polarised skylight, the sun's position or the colour gradient of the sky. Ants without any directional information from their path-integration system (zero-vector) were tested, also with covered compound eyes and open ocelli, on a familiar training field where they have to use the surrounding panorama to home. These ants failed to orient significantly in the homeward direction. Together, our results demonstrated that M. bagoti could perceive and process celestial compass information for directional orientation with their ocelli. In contrast, the ocelli do not seem to contribute to terrestrial landmark-based navigation in M. bagoti.

A nocturnal mammal, the greater mouse-eared bat, calibrates a magnetic compass by the sun

PubMed Central

Holland, Richard A.; Borissov, Ivailo; Siemers, Björn M.

2010-01-01

Recent evidence suggests that bats can detect the geomagnetic field, but the way in which this is used by them for navigation to a home roost remains unresolved. The geomagnetic field may be used by animals both to indicate direction and to locate position. In birds, directional information appears to be derived from an interaction of the magnetic field with either the sun or the stars, with some evidence suggesting that sunset/sunrise provides the primary directional reference by which a magnetic compass is calibrated daily. We demonstrate that homing greater mouse-eared bats (Myotis myotis) calibrate a magnetic compass with sunset cues by testing their homing response after exposure to an altered magnetic field at and after sunset. Magnetic manipulation at sunset resulted in a counterclockwise shift in orientation compared with controls, consistent with sunset calibration of the magnetic field, whereas magnetic manipulation after sunset resulted in no change in orientation. Unlike in birds, however, the pattern of polarization was not necessary for the calibration. For animals that occupy ecological niches where the sunset is rarely observed, this is a surprising finding. Yet it may indicate the primacy of the sun as an absolute geographical reference not only for birds but also within other vertebrate taxa. PMID:20351296

Behavioural and physiological mechanisms of polarized light sensitivity in birds.

PubMed

Muheim, Rachel

2011-03-12

Polarized light (PL) sensitivity is relatively well studied in a large number of invertebrates and some fish species, but in most other vertebrate classes, including birds, the behavioural and physiological mechanism of PL sensitivity remains one of the big mysteries in sensory biology. Many organisms use the skylight polarization pattern as part of a sun compass for orientation, navigation and in spatial orientation tasks. In birds, the available evidence for an involvement of the skylight polarization pattern in sun-compass orientation is very weak. Instead, cue-conflict and cue-calibration experiments have shown that the skylight polarization pattern near the horizon at sunrise and sunset provides birds with a seasonally and latitudinally independent compass calibration reference. Despite convincing evidence that birds use PL cues for orientation, direct experimental evidence for PL sensitivity is still lacking. Avian double cones have been proposed as putative PL receptors, but detailed anatomical and physiological evidence will be needed to conclusively describe the avian PL receptor. Intriguing parallels between the functional and physiological properties of PL reception and light-dependent magnetoreception could point to a common receptor system.

Behavioural and physiological mechanisms of polarized light sensitivity in birds

PubMed Central

Muheim, Rachel

2011-01-01

Polarized light (PL) sensitivity is relatively well studied in a large number of invertebrates and some fish species, but in most other vertebrate classes, including birds, the behavioural and physiological mechanism of PL sensitivity remains one of the big mysteries in sensory biology. Many organisms use the skylight polarization pattern as part of a sun compass for orientation, navigation and in spatial orientation tasks. In birds, the available evidence for an involvement of the skylight polarization pattern in sun-compass orientation is very weak. Instead, cue-conflict and cue-calibration experiments have shown that the skylight polarization pattern near the horizon at sunrise and sunset provides birds with a seasonally and latitudinally independent compass calibration reference. Despite convincing evidence that birds use PL cues for orientation, direct experimental evidence for PL sensitivity is still lacking. Avian double cones have been proposed as putative PL receptors, but detailed anatomical and physiological evidence will be needed to conclusively describe the avian PL receptor. Intriguing parallels between the functional and physiological properties of PL reception and light-dependent magnetoreception could point to a common receptor system. PMID:21282180

Way-finding in displaced clock-shifted bees proves bees use a cognitive map

PubMed Central

Cheeseman, James F.; Millar, Craig D.; Greggers, Uwe; Lehmann, Konstantin; Pawley, Matthew D. M.; Gallistel, Charles R.; Warman, Guy R.; Menzel, Randolf

2014-01-01

Mammals navigate by means of a metric cognitive map. Insects, most notably bees and ants, are also impressive navigators. The question whether they, too, have a metric cognitive map is important to cognitive science and neuroscience. Experimentally captured and displaced bees often depart from the release site in the compass direction they were bent on before their capture, even though this no longer heads them toward their goal. When they discover their error, however, the bees set off more or less directly toward their goal. This ability to orient toward a goal from an arbitrary point in the familiar environment is evidence that they have an integrated metric map of the experienced environment. We report a test of an alternative hypothesis, which is that all the bees have in memory is a collection of snapshots that enable them to recognize different landmarks and, associated with each such snapshot, a sun-compass–referenced home vector derived from dead reckoning done before and after previous visits to the landmark. We show that a large shift in the sun-compass rapidly induced by general anesthesia does not alter the accuracy or speed of the homeward-oriented flight made after the bees discover the error in their initial postrelease flight. This result rules out the sun-referenced home-vector hypothesis, further strengthening the now extensive evidence for a metric cognitive map in bees. PMID:24889633

Integration and flight test of a biomimetic heading sensor

NASA Astrophysics Data System (ADS)

Chahl, Javaan; Mizutani, Akiko

2013-04-01

We report on the first successful development and implementation of an automatic polarisation compass as the primary heading sensor for a UAV. Polarisation compassing is the primary navigation sense of many flying and walking insects, including bees, ants and crickets. Manually operated polarisation astrolabes were fitted in some passenger airliners prior to the implementation of the global positioning system, to compensate for the overal degradation of magnetic and gyrocompass sensors in polar regions. The device we developed demonstrated accurate determination of the direction of the Sun, with repeatability of better than 0.2 degrees. These figures are comparable to any solid state magnetic compass, including flux gate based devices. Flight trials were undertaken in which the output of the polarimeter was the only heading reference used by the aircraft as it flew through GPS waypoints.

Success of sky-polarimetric Viking navigation: revealing the chance Viking sailors could reach Greenland from Norway

NASA Astrophysics Data System (ADS)

Száz, Dénes; Horváth, Gábor

2018-04-01

According to a famous hypothesis, Viking sailors could navigate along the latitude between Norway and Greenland by means of sky polarization in cloudy weather using a sun compass and sunstone crystals. Using data measured in earlier atmospheric optical and psychophysical experiments, here we determine the success rate of this sky-polarimetric Viking navigation. Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3-week-long journey as a function of the navigation periodicity Δt if they analysed sky polarization with calcite, cordierite or tourmaline sunstones. Examples of voyage routes are also presented. Our results show that the sky-polarimetric navigation is surprisingly successful on both days of the spring equinox and summer solstice even under cloudy conditions if the navigator determined the north direction periodically at least once in every 3 h, independently of the type of sunstone used for the analysis of sky polarization. This explains why the Vikings could rule the Atlantic Ocean for 300 years and could reach North America without a magnetic compass. Our findings suggest that it is not only the navigation periodicity in itself that is important for higher navigation success rates, but also the distribution of times when the navigation procedure carried out is as symmetrical as possible with respect to the time point of real noon.

Success of sky-polarimetric Viking navigation: revealing the chance Viking sailors could reach Greenland from Norway.

PubMed

Száz, Dénes; Horváth, Gábor

2018-04-01

According to a famous hypothesis, Viking sailors could navigate along the latitude between Norway and Greenland by means of sky polarization in cloudy weather using a sun compass and sunstone crystals. Using data measured in earlier atmospheric optical and psychophysical experiments, here we determine the success rate of this sky-polarimetric Viking navigation. Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3-week-long journey as a function of the navigation periodicity Δ t if they analysed sky polarization with calcite, cordierite or tourmaline sunstones. Examples of voyage routes are also presented. Our results show that the sky-polarimetric navigation is surprisingly successful on both days of the spring equinox and summer solstice even under cloudy conditions if the navigator determined the north direction periodically at least once in every 3 h, independently of the type of sunstone used for the analysis of sky polarization. This explains why the Vikings could rule the Atlantic Ocean for 300 years and could reach North America without a magnetic compass. Our findings suggest that it is not only the navigation periodicity in itself that is important for higher navigation success rates, but also the distribution of times when the navigation procedure carried out is as symmetrical as possible with respect to the time point of real noon.

Success of sky-polarimetric Viking navigation: revealing the chance Viking sailors could reach Greenland from Norway

PubMed Central

Száz, Dénes; Horváth, Gábor

2018-01-01

According to a famous hypothesis, Viking sailors could navigate along the latitude between Norway and Greenland by means of sky polarization in cloudy weather using a sun compass and sunstone crystals. Using data measured in earlier atmospheric optical and psychophysical experiments, here we determine the success rate of this sky-polarimetric Viking navigation. Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3-week-long journey as a function of the navigation periodicity Δt if they analysed sky polarization with calcite, cordierite or tourmaline sunstones. Examples of voyage routes are also presented. Our results show that the sky-polarimetric navigation is surprisingly successful on both days of the spring equinox and summer solstice even under cloudy conditions if the navigator determined the north direction periodically at least once in every 3 h, independently of the type of sunstone used for the analysis of sky polarization. This explains why the Vikings could rule the Atlantic Ocean for 300 years and could reach North America without a magnetic compass. Our findings suggest that it is not only the navigation periodicity in itself that is important for higher navigation success rates, but also the distribution of times when the navigation procedure carried out is as symmetrical as possible with respect to the time point of real noon. PMID:29765673

Navigation by light polarization in clear and turbid waters

PubMed Central

Lerner, Amit; Sabbah, Shai; Erlick, Carynelisa; Shashar, Nadav

2011-01-01

Certain terrestrial animals use sky polarization for navigation. Certain aquatic species have also been shown to orient according to a polarization stimulus, but the correlation between underwater polarization and Sun position and hence the ability to use underwater polarization as a compass for navigation is still under debate. To examine this issue, we use theoretical equations for per cent polarization and electric vector (e-vector) orientation that account for the position of the Sun, refraction at the air–water interface and Rayleigh single scattering. The polarization patterns predicted by these theoretical equations are compared with measurements conducted in clear and semi-turbid coastal sea waters at 2 m and 5 m depth over sea floors of 6 m and 28 m depth. We find that the per cent polarization is correlated with the Sun's elevation only in clear waters. We furthermore find that the maximum value of the e-vector orientation angle equals the angle of refraction only in clear waters, in the horizontal viewing direction, over the deeper sea floor. We conclude that navigation by use of underwater polarization is possible under restricted conditions, i.e. in clear waters, primarily near the horizontal viewing direction, and in locations where the sea floor has limited effects on the light's polarization. PMID:21282170

Homing Pigeons Respond to Time-Compensated Solar Cues Even in Sight of the Loft

PubMed Central

Armstrong, Chris; Wilkinson, Helen; Meade, Jessica; Biro, Dora; Freeman, Robin; Guilford, Tim

2013-01-01

The sun has long been thought to guide bird navigation as the second step in a two-stage process, in which determining position using a map is followed by course setting using a compass, both over unfamiliar and familiar terrain. The animal’s endogenous clock time-compensates the solar compass for the sun’s apparent movement throughout the day, and this allows predictable deflections in orientation to test for the compass’ influence using clock-shift manipulations. To examine the influence of the solar compass during a highly familiar navigational task, 24 clock-shifted homing pigeons were precision-tracked from a release site close to and in sight of their final goal, the colony loft. The resulting trajectories displayed significant partial deflection from the loft direction as predicted by either fast or slow clock-shift treatments. The partial deflection was also found to be stable along the entire trajectory indicating regular updating of orientation via input from the solar compass throughout the final approach flight to the loft. Our results demonstrate that time-compensated solar cues are deeply embedded in the way birds orient during homing flight, are accessed throughout the journey and on a remarkably fine-grained scale, and may be combined effectively simultaneously with direct guidance from familiar landmarks, even when birds are flying towards a directly visible goal. PMID:23717401

Honeybee navigation: critically examining the role of the polarization compass

PubMed Central

Evangelista, C.; Kraft, P.; Dacke, M.; Labhart, T.; Srinivasan, M. V.

2014-01-01

Although it is widely accepted that honeybees use the polarized-light pattern of the sky as a compass for navigation, there is little direct evidence that this information is actually sensed during flight. Here, we ask whether flying bees can obtain compass cues derived purely from polarized light, and communicate this information to their nest-mates through the ‘waggle dance’. Bees, from an observation hive with vertically oriented honeycombs, were trained to fly to a food source at the end of a tunnel, which provided overhead illumination that was polarized either parallel to the axis of the tunnel, or perpendicular to it. When the illumination was transversely polarized, bees danced in a predominantly vertical direction with waggles occurring equally frequently in the upward or the downward direction. They were thus using the polarized-light information to signal the two possible directions in which they could have flown in natural outdoor flight: either directly towards the sun, or directly away from it. When the illumination was axially polarized, the bees danced in a predominantly horizontal direction with waggles directed either to the left or the right, indicating that they could have flown in an azimuthal direction that was 90° to the right or to the left of the sun, respectively. When the first half of the tunnel provided axial illumination and the second half transverse illumination, bees danced along all of the four principal diagonal directions, which represent four equally likely locations of the food source based on the polarized-light information that they had acquired during their journey. We conclude that flying bees are capable of obtaining and signalling compass information that is derived purely from polarized light. Furthermore, they deal with the directional ambiguity that is inherent in polarized light by signalling all of the possible locations of the food source in their dances, thus maximizing the chances of recruitment to it. PMID:24395964

Honeybee navigation: critically examining the role of the polarization compass.

PubMed

Evangelista, C; Kraft, P; Dacke, M; Labhart, T; Srinivasan, M V

2014-01-01

Although it is widely accepted that honeybees use the polarized-light pattern of the sky as a compass for navigation, there is little direct evidence that this information is actually sensed during flight. Here, we ask whether flying bees can obtain compass cues derived purely from polarized light, and communicate this information to their nest-mates through the 'waggle dance'. Bees, from an observation hive with vertically oriented honeycombs, were trained to fly to a food source at the end of a tunnel, which provided overhead illumination that was polarized either parallel to the axis of the tunnel, or perpendicular to it. When the illumination was transversely polarized, bees danced in a predominantly vertical direction with waggles occurring equally frequently in the upward or the downward direction. They were thus using the polarized-light information to signal the two possible directions in which they could have flown in natural outdoor flight: either directly towards the sun, or directly away from it. When the illumination was axially polarized, the bees danced in a predominantly horizontal direction with waggles directed either to the left or the right, indicating that they could have flown in an azimuthal direction that was 90° to the right or to the left of the sun, respectively. When the first half of the tunnel provided axial illumination and the second half transverse illumination, bees danced along all of the four principal diagonal directions, which represent four equally likely locations of the food source based on the polarized-light information that they had acquired during their journey. We conclude that flying bees are capable of obtaining and signalling compass information that is derived purely from polarized light. Furthermore, they deal with the directional ambiguity that is inherent in polarized light by signalling all of the possible locations of the food source in their dances, thus maximizing the chances of recruitment to it.

Sky Compass Orientation in Desert Locusts-Evidence from Field and Laboratory Studies.

PubMed

Homberg, Uwe

2015-01-01

Locusts are long-range migratory insects. At high population density, immature animals form marching hopper bands while adults take off and form huge swarms of millions of animals. At low population densities animals are solitarious, but likewise migrate, mostly during the night. Numerous studies aimed at predicting locust infestations showed that migrations both as hopper bands and as adults are largely downwind following seasonal shifts of the tropical convergence zone taking the animals to areas of rainfall. Only a few studies provided evidence for active orientation mechanisms, including the involvement of a sun compass. This scarcity of evidence stands in contrast to recent neurobiological data showing sophisticated neuronal adaptations suited for sky compass navigation. These include a special dorsal eye region with photoreceptors suited to analyze the polarization pattern of the sky and a system of topographically arranged sky compass neurons in the central complex of the brain. Laboratory experiments, moreover, demonstrated polarotaxis in tethered flying animals. The discrepancy of these findings call for more rigorous field studies on active orientation mechanisms in locusts. It remains to be shown how locusts use their internal sky compass during mass migrations and what role it plays to guide solitarious locusts in their natural habitat.

Should Animals Navigating Over Short Distances Switch to a Magnetic Compass Sense?

PubMed Central

Wyeth, Russell C.

2010-01-01

Magnetoreception can play a substantial role in long distance navigation by animals. I hypothesize that locomotion guided by a magnetic compass sense could also play a role in short distance navigation. Animals identify mates, prey, or other short distance navigational goals using different sensory modalities (olfaction, vision, audition, etc.) to detect sensory cues associated with those goals. In conditions where these cues become unreliable for navigation (due to flow changes, obstructions, noise interference, etc.), switching to a magnetic compass sense to guide locomotion toward the navigational goals could be beneficial. Using simulations based on known locomotory and flow parameters, I show this strategy has strong theoretical benefits for the nudibranch mollusk Tritonia diomedea navigating toward odor sources in variable flow. A number of other animals may garner similar benefits, particularly slow-moving species in environments with rapidly changing cues relevant for navigation. Faster animals might also benefit from switching to a magnetic compass sense, provided the initial cues used for navigation (acoustic signals, odors, etc.) are intermittent or change rapidly enough that the entire navigation behavior cannot be guided by a continuously detectable cue. Examination of the relative durations of navigational tasks, the persistence of navigational cues, and the stability of both navigators and navigational targets will identify candidates with the appropriate combination of unreliable initial cues and relatively immobile navigational goals for which this hypothetical behavior could be beneficial. Magnetic manipulations can then test whether a switch to a magnetic compass sense occurs. This hypothesis thus provides an alternative when considering the behavioral significance of a magnetic compass sense in animals. PMID:20740070

Experience-related reorganization of giant synapses in the lateral complex: Potential role in plasticity of the sky-compass pathway in the desert ant Cataglyphis fortis.

PubMed

Schmitt, Franziska; Stieb, Sara Mae; Wehner, Rüdiger; Rössler, Wolfgang

2016-04-01

Cataglyphis desert ants undergo an age-related polyethism from interior workers to relatively short-lived foragers with remarkable visual navigation capabilities, predominantly achieved by path integration using a polarized skylight-based sun compass and a stride-integrating odometer. Behavioral and physiological experiments revealed that the polarization (POL) pattern is processed via specialized UV-photoreceptors in the dorsal rim area of the compound eye and POL sensitive optic lobe neurons. Further information about the neuronal substrate for processing of POL information in the ant brain has remained elusive. This work focuses on the lateral complex (LX), known as an important relay station in the insect sky-compass pathway. Neuroanatomical results in Cataglyphis fortis show that LX giant synapses (GS) connect large presynaptic terminals from anterior optic tubercle neurons with postsynaptic GABAergic profiles of tangential neurons innervating the ellipsoid body of the central complex. At the ultrastructural level, the cup-shaped presynaptic structures comprise many active zones contacting numerous small postsynaptic profiles. Three-dimensional quantification demonstrated a significantly higher number of GS (∼ 13%) in foragers compared with interior workers. Light exposure, as opposed to age, was necessary and sufficient to trigger a similar increase in GS numbers. Furthermore, the increase in GS numbers was sensitive to the exclusion of UV light. As previous experiments have demonstrated the importance of the UV spectrum for sky-compass navigation in Cataglyphis, we conclude that plasticity in LX GS may reflect processes involved in the initial calibration of sky-compass neuronal circuits during orientation walks preceding active foraging. © 2015 Wiley Periodicals, Inc.

Accuracy Analysis of Precise Point Positioning of Compass Navigation System Applied to Crustal Motion Monitoring

NASA Astrophysics Data System (ADS)

Wang, Yuebing

2017-04-01

Based on the observation data of Compass/GPSobserved at five stations, time span from July 1, 2014 to June 30, 2016. UsingPPP positioning model of the PANDA software developed by Wuhan University,Analyzedthe positioning accuracy of single system and Compass/GPS integrated resolving, and discussed the capability of Compass navigation system in crustal motion monitoring. The results showed that the positioning accuracy in the east-west directionof the Compass navigation system is lower than the north-south direction (the positioning accuracy de 3 times RMS), in general, the positioning accuracyin the horizontal direction is about 1 2cm and the vertical direction is about 5 6cm. The GPS positioning accuracy in the horizontal direction is better than 1cm and the vertical direction is about 1 2cm. The accuracy of Compass/GPS integrated resolving is quite to GPS. It is worth mentioning that although Compass navigation system precision point positioning accuracy is lower than GPS, two sets of velocity fields obtained by using the Nikolaidis (2002) model to analyze the Compass and GPS time series results respectively, the results showed that the maximum difference of the two sets of velocity field in horizontal directions is 1.8mm/a. The Compass navigation system can now be used to monitor the crustal movement of the large deformation area, based on the velocity field in horizontal direction.

Migration along orthodromic sun compass routes by arctic birds.

PubMed

Alerstam, T; Gudmundsson, G A; Green, M; Hedenstrom, A

2001-01-12

Flight directions of birds migrating at high geographic and magnetic latitudes can be used to test bird orientation by celestial or geomagnetic compass systems under polar conditions. Migration patterns of arctic shorebirds, revealed by tracking radar studies during an icebreaker expedition along the Northwest Passage in 1999, support predicted sun compass trajectories but cannot be reconciled with orientation along either geographic or magnetic loxodromes (rhumb lines). Sun compass routes are similar to orthodromes (great circle routes) at high latitudes, showing changing geographic courses as the birds traverse longitudes and their internal clock gets out of phase with local time. These routes bring the shorebirds from high arctic Canada to the east coast of North America, from which they make transoceanic flights to South America. The observations are also consistent with a migration link between Siberia and the Beaufort Sea region by way of sun compass routes across the Arctic Ocean.

Compensation for fluctuations in crosswind drift without stationary landmarks in butterflies migrating over seas.

PubMed

Srygley, Robert B.

2001-01-01

Migrating insects may fly over large bodies of water that lack landmarks, but little is known about their ability to navigate in such a fluid environment. Using boat navigation instruments to measure compensation for fluctuations in crosswind drift, I investigated the ability of butterflies (Lepidoptera: Hesperiidae, Nymphalidae and Pieridae) to orient with and without landmarks as they migrated naturally over the Caribbean Sea. I used the presence or absence of landmarks or clouds to evaluate their use by the butterflies as guides for compensation. Forty-one per cent of the butterflies compensated for crosswind drift, whereas only 16% did not compensate. No conclusion could be drawn for the remainder. Without landmarks or clouds, butterflies were significantly less likely to compensate for drift than when these local cues were present. Butterflies were more likely to compensate fully in the presence of a landmark than when only clouds were present. Phoebis sennae butterflies drifted in the morning and overcompensated for drift in the afternoon, a pattern found both within and between individuals independent of landmarks. Although I cannot exclude the use of clouds, this would probably result in undercompensation. Hence, a ground reference in conjunction with a sun or magnetic compass is the most likely orientation cue. In the absence of clouds, one butterfly compensated, at least in part, indicating that it was using ripples on the sea surface as a ground reference in conjunction with a sun or magnetic compass. Copyright 2001 The Association for the Study of Animal Behaviour.

Celestial orientation with the sun not in view: lizards use a time-compensated sky polarization compass.

PubMed

Maoret, Francesco; Beltrami, Giulia; Bertolucci, Cristiano; Foà, Augusto

2014-04-01

The present investigation was aimed at testing whether the lizard sky polarization compass is time compensated. For this purpose, ruin lizards, Podarcis sicula, were both trained and tested for orientation inside a Morris water maze under clear skies with the sun not in view. During training, lizards showed a striking bimodal orientation along the training axis, demonstrating their capability of determining the symmetry plane of the sky polarization pattern and thus the use of polarization information in orientation. After reaching criteria, lizards were kept 7 days in a 6-h fast clock-shift treatment and then released with the sun not in view. Six-hour clock-shifted lizards showed a bimodal distribution of directional choices, which was oriented perpendicularly to the training axis, as it was expected on the basis of the clock-shift. The results show that the only celestial diurnal compass mechanism that does not need a direct vision of the sun disk (i.e., the sky polarization compass) is a time-compensated compass.

Compass Games: An Introduction to Orienteering Skills

ERIC Educational Resources Information Center

Sension-Hall, Debra

2011-01-01

Compasses are useful tools for teaching the basics of navigation. Knowing where you are, where you are going, and how to get there are important facets of outdoor recreation. Compass games are a fun way to teach introductory navigation skills, and this article describes how they can be used as innovative, nontraditional activities in physical…

Orientation of lizards in a Morris water-maze: roles of the sun compass and the parietal eye.

PubMed

Foà, Augusto; Basaglia, Francesca; Beltrami, Giulia; Carnacina, Margherita; Moretto, Elisa; Bertolucci, Cristiano

2009-09-15

The present study examined for the first time whether a Morris water-maze can be used to explore compass and other orientation mechanisms in the ruin lizard Podarcis sicula. In the open field, during sunny days, lizards were individually trained to swim from the center of the water maze onto a hidden platform (the goal), positioned at the periphery of the maze in a single compass direction. The goal was invisible because it was placed just beneath the water surface and the water was rendered opaque. The results showed that lizards learn to swim directly towards the hidden goal under the sun in the absence of visual feature cues. We further examined whether the observed orientation response would be due to lizards learning the spatial position of the goal relative to the sun's azimuth, i.e. to the use of a time-compensated sun compass. Lizards reaching learning criteria were subjected to 6 h clock-shift (fast or slow), and tested for goal orientation in the Morris water-maze. Results demonstrated that the learned orientation response is mediated by a time-compensated sun compass. Further investigations provided direct evidence that in ruin lizards an intact parietal eye is required to perform goal orientation under the sun inside a Morris water-maze, and that other brain photoreceptors, like the pineal or deep brain photoreceptors, are not involved in orientation.

Sun-compass orientation in homing pigeons: compensation for different rates of change in azimuth?

PubMed

Wiltschko, R; Walker, M; Wiltschko, W

2000-03-01

Birds using their sun compass must compensate for the apparent movement of the sun with the help of their internal clock. The movement of the sun is not uniform, being much faster around noon than near sunrise and sunset. If the sun-compass mechanisms are not adjusted to these variations, considerable errors might arise. To learn whether birds are able to take the different rates of sun azimuth change into account, we subjected homing pigeons to a 4 h fast clock-shift. The experiments were performed near Auckland, New Zealand, at a latitude of 37 degrees S, where the expected deflections for a 4 h shift in summer vary from less than 40 degrees to more than 120 degrees, depending on time of day. One group of birds was released just after sunrise or during the corresponding period in the afternoon when the expected deflections were minimal, the other group during late morning when they were maximal. The different sizes of the observed deflections - between 26 degrees and 51 degrees in the first group, and between 107 degrees and 153 degrees in the second group - clearly show that the birds' compensation mechanisms are closely tuned to the varying rates of change in sun azimuth. The results suggest that pigeons have a rather precise internal representation of the sun curve, which makes the avian sun compass a highly accurate mechanism of direction finding.

Evidence for discrete solar and lunar orientation mechanisms in the beach amphipod, Talitrus saltator Montagu (Crustacea, Amphipoda)

PubMed Central

Ugolini, Alberto; Hoelters, Laura S.; Ciofini, Alice; Pasquali, Vittorio; Wilcockson, David C.

2016-01-01

Animals that use astronomical cues to orientate must make continuous adjustment to account for temporal changes in azimuth caused by Earth’s rotation. For example, the Monarch butterfly possesses a time-compensated sun compass dependent upon a circadian clock in the antennae. The amphipod Talitrus saltator possesses both a sun compass and a moon compass. We reasoned that the time-compensated compass mechanism that enables solar orientation of T. saltator is located in the antennae, as is the case for Monarch butterflies. We examined activity rhythms and orientation of sandhoppers with antennae surgically removed, or unilaterally occluded with black paint. Removing or painting the antennae did not affect daily activity rhythms or competence to orientate using the sun. However, when tested at night these animals were unable to orientate correctly to the moon. We subsequently measured circadian gene expression in the antennae and brain of T. saltator and show the clock genes period and cryptochrome 2 are rhythmically expressed in both tissues, reminiscent of other arthropods known to possess antennal clocks. Together, our behavioural and molecular data suggest that, T. saltator has anatomically discrete lunar and solar orientation apparatus; a sun compass, likely located in the brain and a moon compass in the antennae. PMID:27759059

Evidence for discrete solar and lunar orientation mechanisms in the beach amphipod, Talitrus saltator Montagu (Crustacea, Amphipoda)

NASA Astrophysics Data System (ADS)

Ugolini, Alberto; Hoelters, Laura S.; Ciofini, Alice; Pasquali, Vittorio; Wilcockson, David C.

2016-10-01

Animals that use astronomical cues to orientate must make continuous adjustment to account for temporal changes in azimuth caused by Earth’s rotation. For example, the Monarch butterfly possesses a time-compensated sun compass dependent upon a circadian clock in the antennae. The amphipod Talitrus saltator possesses both a sun compass and a moon compass. We reasoned that the time-compensated compass mechanism that enables solar orientation of T. saltator is located in the antennae, as is the case for Monarch butterflies. We examined activity rhythms and orientation of sandhoppers with antennae surgically removed, or unilaterally occluded with black paint. Removing or painting the antennae did not affect daily activity rhythms or competence to orientate using the sun. However, when tested at night these animals were unable to orientate correctly to the moon. We subsequently measured circadian gene expression in the antennae and brain of T. saltator and show the clock genes period and cryptochrome 2 are rhythmically expressed in both tissues, reminiscent of other arthropods known to possess antennal clocks. Together, our behavioural and molecular data suggest that, T. saltator has anatomically discrete lunar and solar orientation apparatus; a sun compass, likely located in the brain and a moon compass in the antennae.

The role of the sun in the celestial compass of dung beetles

PubMed Central

Dacke, M.; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

2014-01-01

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day. PMID:24395963

The role of the sun in the celestial compass of dung beetles.

PubMed

Dacke, M; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

2014-01-01

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day.

A method for lunar roving vehicle position determination from three landmark observations with a sun compass

NASA Technical Reports Server (NTRS)

Blucker, T. J.; Stimmel, G. L.

1971-01-01

A simplified method is described for determining the position of the lunar roving vehicle on the lunar surface during Apollo 15. The method is based upon sun compass azimuth measurements of three lunar landmarks. The difference between the landmark azimuth and the sun azimuth is measured and the resulting data are voice relayed to the Mission Control Center for processing.

COMPASS time synchronization and dissemination—Toward centimetre positioning accuracy

NASA Astrophysics Data System (ADS)

Wang, ZhengBo; Zhao, Lu; Wang, ShiGuang; Zhang, JianWei; Wang, Bo; Wang, LiJun

2014-09-01

In this paper we investigate methods to achieve highly accurate time synchronization among the satellites of the COMPASS global navigation satellite system (GNSS). Owing to the special design of COMPASS which implements several geo-stationary satellites (GEO), time synchronization can be highly accurate via microwave links between ground stations to the GEO satellites. Serving as space-borne relay stations, the GEO satellites can further disseminate time and frequency signals to other satellites such as the inclined geo-synchronous (IGSO) and mid-earth orbit (MEO) satellites within the system. It is shown that, because of the accuracy in clock synchronization, the theoretical accuracy of COMPASS positioning and navigation will surpass that of the GPS. In addition, the COMPASS system can function with its entire positioning, navigation, and time-dissemination services even without the ground link, thus making it much more robust and secure. We further show that time dissemination using the COMPASS-GEO satellites to earth-fixed stations can achieve very high accuracy, to reach 100 ps in time dissemination and 3 cm in positioning accuracy, respectively. In this paper, we also analyze two feasible synchronization plans. All special and general relativistic effects related to COMPASS clocks frequency and time shifts are given. We conclude that COMPASS can reach centimeter-level positioning accuracy and discuss potential applications.

46 CFR 184.402 - Compasses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.402 Compasses. (a) Except as otherwise provided in this section every vessel must be fitted with a suitable magnetic compass designed for marine use...

46 CFR 184.402 - Compasses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.402 Compasses. (a) Except as otherwise provided in this section every vessel must be fitted with a suitable magnetic compass designed for marine use...

46 CFR 184.402 - Compasses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.402 Compasses. (a) Except as otherwise provided in this section every vessel must be fitted with a suitable magnetic compass designed for marine use...

46 CFR 121.402 - Compasses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Navigation Equipment § 121.402 Compasses. (a) Except as otherwise provided in this section every vessel must be fitted with a suitable magnetic compass designed for marine use, to be mounted at the primary...

46 CFR 121.402 - Compasses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Navigation Equipment § 121.402 Compasses. (a) Except as otherwise provided in this section every vessel must be fitted with a suitable magnetic compass designed for marine use, to be mounted at the primary...

46 CFR 121.402 - Compasses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Navigation Equipment § 121.402 Compasses. (a) Except as otherwise provided in this section every vessel must be fitted with a suitable magnetic compass designed for marine use, to be mounted at the primary...

SGMM: Smart Grid Maturity Model. A Zero-depth Entry to Using the TSP: How TSP Was Used to Turn Around the SGMM Project that Was Drowning in Details

DTIC Science & Technology

2014-11-04

Compass Survey Questionnaire-based assessment yields maturity ratings and comparisons Navigation Process Expert-led workshops to complete... Compass and use results to develop consensus aspirations Training Overview Seminar and SGMM Navigator Course Partner Program License organizations...journey 19 SGMM Compass Survey Contains • One question for each expected characteristic in the model and • Attribute and performance questions

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies

PubMed Central

Grob, Robin; Fleischmann, Pauline N.; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance—presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system. PMID:29184487

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies.

PubMed

Grob, Robin; Fleischmann, Pauline N; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance-presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system.

Magnetic Field Aided Indoor Navigation

DTIC Science & Technology

2009-03-01

fields; this 13 compass was made to look like the big dipper , so that the end of the bowl would point in the horizontal northward direction, also like...the big dipper [1]. From these early observations and uses, merchants began using compasses to navigate to their various trading locations. This was

Accuracy of the hypothetical sky-polarimetric Viking navigation versus sky conditions: revealing solar elevations and cloudinesses favourable for this navigation method

NASA Astrophysics Data System (ADS)

Száz, Dénes; Farkas, Alexandra; Barta, András; Kretzer, Balázs; Blahó, Miklós; Egri, Ádám; Szabó, Gyula; Horváth, Gábor

2017-09-01

According to Thorkild Ramskou's theory proposed in 1967, under overcast and foggy skies, Viking seafarers might have used skylight polarization analysed with special crystals called sunstones to determine the position of the invisible Sun. After finding the occluded Sun with sunstones, its elevation angle had to be measured and its shadow had to be projected onto the horizontal surface of a sun compass. According to Ramskou's theory, these sunstones might have been birefringent calcite or dichroic cordierite or tourmaline crystals working as polarizers. It has frequently been claimed that this method might have been suitable for navigation even in cloudy weather. This hypothesis has been accepted and frequently cited for decades without any experimental support. In this work, we determined the accuracy of this hypothetical sky-polarimetric Viking navigation for 1080 different sky situations characterized by solar elevation θ and cloudiness ρ, the sky polarization patterns of which were measured by full-sky imaging polarimetry. We used the earlier measured uncertainty functions of the navigation steps 1, 2 and 3 for calcite, cordierite and tourmaline sunstone crystals, respectively, and the newly measured uncertainty function of step 4 presented here. As a result, we revealed the meteorological conditions under which Vikings could have used this hypothetical navigation method. We determined the solar elevations at which the navigation uncertainties are minimal at summer solstice and spring equinox for all three sunstone types. On average, calcite sunstone ensures a more accurate sky-polarimetric navigation than tourmaline and cordierite. However, in some special cases (generally at 35° ≤ θ ≤ 40°, 1 okta ≤ ρ ≤ 6 oktas for summer solstice, and at 20° ≤ θ ≤ 25°, 0 okta ≤ ρ ≤ 4 oktas for spring equinox), the use of tourmaline and cordierite results in smaller navigation uncertainties than that of calcite. Generally, under clear or less cloudy skies, the sky-polarimetric navigation is more accurate, but at low solar elevations its accuracy remains relatively large even at high cloudiness. For a given ρ, the absolute value of averaged peak North uncertainties dramatically decreases with increasing θ until the sign (±) change of these uncertainties. For a given θ, this absolute value can either decrease or increase with increasing ρ. The most advantageous sky situations for this navigation method are at summer solstice when the solar elevation and cloudiness are 35° ≤ θ ≤ 40° and 2 oktas ≤ ρ ≤ 3 oktas.

Do monarch butterflies use polarized skylight for migratory orientation?

PubMed

Stalleicken, Julia; Mukhida, Maya; Labhart, Thomas; Wehner, Rüdiger; Frost, Barrie; Mouritsen, Henrik

2005-06-01

To test if migratory monarch butterflies use polarized light patterns as part of their time-compensated sun compass, we recorded their virtual flight paths in a flight simulator while the butterflies were exposed to patches of naturally polarized blue sky, artificial polarizers or a sunny sky. In addition, we tested butterflies with and without the polarized light detectors of their compound eye being occluded. The monarchs' orientation responses suggested that the butterflies did not use the polarized light patterns as a compass cue, nor did they exhibit a specific alignment response towards the axis of polarized light. When given direct view of the sun, migratory monarchs with their polarized light detectors painted out were still able to use their time-compensated compass: non-clockshifted butterflies, with their dorsal rim area occluded, oriented in their typical south-southwesterly migratory direction. Furthermore, they shifted their flight course clockwise by the predicted approximately 90 degrees after being advance clockshifted 6 h. We conclude that in migratory monarch butterflies, polarized light cues are not necessary for a time-compensated celestial compass to work and that the azimuthal position of the sun disc and/or the associated light-intensity and spectral gradients seem to be the migrants' major compass cue.

Neural mechanisms in insect navigation: polarization compass and odometer.

PubMed

Labhart, Thomas; Meyer, Eric P

2002-12-01

Insect navigation relies on path integration, a procedure by which information about compass bearings pursued and distances travelled are combined to calculate position. Three neural levels of the polarization compass, which uses the polarization of skylight as a reference, have been analyzed in orthopteran insects. A group of dorsally directed, highly specialized ommatidia serve as polarization sensors. Polarization-opponent neurons in the optic lobe condition the polarization signal by removing unreliable and irrelevant components of the celestial stimulus. Neurons found in the central complex of the brain possibly represent elements of the compass output. The odometer for measuring travelling distances in honeybees relies on optic flow experienced during flight, whereas desert ants most probably use proprioreceptive cues.

The "Set Map" Method of Navigation.

ERIC Educational Resources Information Center

Tippett, Julian

1998-01-01

Explains the "set map" method of using the baseplate compass to solve walkers' navigational needs as opposed to the 1-2-3 method for taking a bearing. The map, with the compass permanently clipped to it, is rotated to the position in which its features have the same orientation as their counterparts on the ground. Includes directions and…

The Experiences of Licensed Mental Health Professionals Who Have Encountered and Navigated through Compassion Fatigue

ERIC Educational Resources Information Center

Jorgensen, Louise B.

2012-01-01

The purpose of this dissertation study was to increase understanding of licensed mental health professionals' experiences as they have encountered and navigated through compassion fatigue (CF). CF is a complex construct with an attendant constellation of secondary stress responses. In order to examine the complex and varying factors…

46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All tankships... 46 Shipping 1 2012-10-01 2012-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section...

46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All tankships...

46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All tankships...

Sensory bases of navigation.

PubMed

Gould, J L

1998-10-08

Navigating animals need to know both the bearing of their goal (the 'map' step), and how to determine that direction (the 'compass' step). Compasses are typically arranged in hierarchies, with magnetic backup as a last resort when celestial information is unavailable. Magnetic information is often essential to calibrating celestial cues, though, and repeated recalibration between celestial and magnetic compasses is important in many species. Most magnetic compasses are based on magnetite crystals, but others make use of induction or paramagnetic interactions between short-wavelength light and visual pigments. Though odors may be used in some cases, most if not all long-range maps probably depend on magnetite. Magnetitebased map senses are used to measure only latitude in some species, but provide the distance and direction of the goal in others.

How do students navigate and learn from nonlinear science texts: Can metanavigation support promote science learning?

NASA Astrophysics Data System (ADS)

Stylianou, Agni

2003-06-01

Digital texts which are based on hypertext and hypermedia technologies are now being used to support science learning. Hypertext offers certain opportunities for learning as well as difficulties that challenge readers to become metacognitively aware of their navigation decisions in order to trade both meaning and structure while reading. The goal of this study was to investigate whether supporting sixth grade students to monitor and regulate their navigation behavior while reading from hypertext would lead to better navigation and learning. Metanavigation support in the form of prompts was provided to groups of students who used a hypertext system called CoMPASS to complete a design challenge. The metanavigation prompts aimed at encouraging students to understand the affordances of the navigational aids in CoMPASS and use them to guide their navigation. The study was conducted in a real classroom setting during the implementation of CoMPASS in sixth grade science classes. Multiple sources of group and individual data were collected and analyzed. Measures included student's individual performance in a pre-science knowledge test, the Metacognitive Awareness of Reading Strategies Inventory (MARSI), a reading comprehension test and a concept map test. Process measures included log file information that captured group navigation paths during the use of CoMPASS. The results suggested that providing metanavigation support enabled the groups to make coherent transitions among the text units. Findings also revealed that reading comprehension, presence of metanavigation support and prior domain knowledge significantly predicted students' individual understanding of science. Implications for hypertext design and literacy research fields are discussed.

Neural integration underlying a time-compensated sun compass in the migratory monarch butterfly

PubMed Central

Shlizerman, Eli; Phillips-Portillo, James; Reppert, Steven M.

2016-01-01

Migrating Eastern North American monarch butterflies use a time-compensated sun compass to adjust their flight to the southwest direction. While the antennal genetic circadian clock and the azimuth of the sun are instrumental for proper function of the compass, it is unclear how these signals are represented on a neuronal level and how they are integrated to produce flight control. To address these questions, we constructed a receptive field model of the compound eye that encodes the solar azimuth. We then derived a neural circuit model, which integrates azimuthal and circadian signals to correct flight direction. The model demonstrates an integration mechanism, which produces robust trajectories reaching the southwest regardless of the time of day and includes a configuration for remigration. Comparison of model simulations with flight trajectories of butterflies in a flight simulator shows analogous behaviors and affirms the prediction that midday is the optimal time for migratory flight. PMID:27149852

The skylight gradient of luminance helps sandhoppers in sun and moon identification.

PubMed

Ugolini, Alberto; Galanti, Giuditta; Mercatelli, Luca

2012-08-15

To return to the ecologically optimal zone of the beach, the sandhopper Talitrus saltator (Montagu) maintains a constant sea-land direction based on the sun and moon compasses. In this study, we investigated the role of the skylight gradient of luminance in sun and moon identification under natural and artificial conditions of illumination. Clock-shifted (inverted) sandhoppers tested under the sun (during their subjective night) and under the full moon (during their subjective day) exhibit orientation in accordance with correct identification of the sun and the moon at night. Tested in artificial conditions of illumination at night without the artificial gradient of luminance, the artificial astronomical cue is identified as the moon even when the conditions of illumination allow sun compass orientation during the day. When the artificial gradient of luminance is added, the artificial astronomical cue is identified as the sun. The role of the sky gradient of luminance in sun and moon identification is discussed on the basis of present and past findings.

Sun Compass Orientation Helps Coral Reef Fish Larvae Return to Their Natal Reef

PubMed Central

Mouritsen, Henrik; Atema, Jelle; Kingsford, Michael J.; Gerlach, Gabriele

2013-01-01

Reef fish sustain populations on isolated reefs and show genetic diversity between nearby reefs even though larvae of many species are swept away from the natal site during pelagic dispersal. Retention or recruitment to natal reefs requires orientation capabilities that enable larvae to find their way. Although olfactory and acoustically based orientation has been implicated in homing when larvae are in the reef’s vicinity, it is still unclear how they cope with greater distances. Here we show evidence for a sun compass mechanism that can bring the larvae to the vicinity of their natal reef. In a circular arena, pre-settlement larvae and early settlers (<24 hours) of the cardinal fish, Ostorhinchus doederleini, showed a strong SSE directional swimming response, which most likely has evolved to compensate for the locally prevailing large scale NNW current drift. When fish were clock-shifted 6 hours, they changed their orientation by ca. 180° as predicted by the tropical sun curve at One Tree Island, i.e. they used a time-compensated sun compass. Furthermore, the fish oriented most consistently at times of the day when the sun azimuth is easy to determine. Microsatellite markers showed that the larvae that had just arrived at One Tree Island genetically belonged to either the local reef population or to Fitzroy Reef located 12 kilometers to the SSE. The use of a sun compass adds a missing long-distance link to the hierarchy of other sensory abilities that can direct larvae to the region of origin, including their natal reef. Predominant local recruitment, in turn, can contribute to genetic isolation and potential speciation. PMID:23840396

Vector navigation in desert ants, Cataglyphis fortis: celestial compass cues are essential for the proper use of distance information.

PubMed

Sommer, Stefan; Wehner, Rüdiger

2005-10-01

Foraging desert ants navigate primarily by path integration. They continually update homing direction and distance by employing a celestial compass and an odometer. Here we address the question of whether information about travel distance is correctly used in the absence of directional information. By using linear channels that were partly covered to exclude celestial compass cues, we were able to test the distance component of the path-integration process while suppressing the directional information. Our results suggest that the path integrator cannot process the distance information accumulated by the odometer while ants are deprived of celestial compass information. Hence, during path integration directional cues are a prerequisite for the proper use of travel-distance information by ants.

Accuracy of the hypothetical sky-polarimetric Viking navigation versus sky conditions: revealing solar elevations and cloudinesses favourable for this navigation method.

PubMed

Száz, Dénes; Farkas, Alexandra; Barta, András; Kretzer, Balázs; Blahó, Miklós; Egri, Ádám; Szabó, Gyula; Horváth, Gábor

2017-09-01

According to Thorkild Ramskou's theory proposed in 1967, under overcast and foggy skies, Viking seafarers might have used skylight polarization analysed with special crystals called sunstones to determine the position of the invisible Sun. After finding the occluded Sun with sunstones, its elevation angle had to be measured and its shadow had to be projected onto the horizontal surface of a sun compass. According to Ramskou's theory, these sunstones might have been birefringent calcite or dichroic cordierite or tourmaline crystals working as polarizers. It has frequently been claimed that this method might have been suitable for navigation even in cloudy weather. This hypothesis has been accepted and frequently cited for decades without any experimental support. In this work, we determined the accuracy of this hypothetical sky-polarimetric Viking navigation for 1080 different sky situations characterized by solar elevation θ and cloudiness ρ , the sky polarization patterns of which were measured by full-sky imaging polarimetry. We used the earlier measured uncertainty functions of the navigation steps 1, 2 and 3 for calcite, cordierite and tourmaline sunstone crystals, respectively, and the newly measured uncertainty function of step 4 presented here. As a result, we revealed the meteorological conditions under which Vikings could have used this hypothetical navigation method. We determined the solar elevations at which the navigation uncertainties are minimal at summer solstice and spring equinox for all three sunstone types. On average, calcite sunstone ensures a more accurate sky-polarimetric navigation than tourmaline and cordierite. However, in some special cases (generally at 35° ≤  θ  ≤ 40°, 1 okta ≤  ρ  ≤ 6 oktas for summer solstice, and at 20° ≤  θ  ≤ 25°, 0 okta ≤  ρ  ≤ 4 oktas for spring equinox), the use of tourmaline and cordierite results in smaller navigation uncertainties than that of calcite. Generally, under clear or less cloudy skies, the sky-polarimetric navigation is more accurate, but at low solar elevations its accuracy remains relatively large even at high cloudiness. For a given ρ , the absolute value of averaged peak North uncertainties dramatically decreases with increasing θ until the sign (±) change of these uncertainties. For a given θ , this absolute value can either decrease or increase with increasing ρ . The most advantageous sky situations for this navigation method are at summer solstice when the solar elevation and cloudiness are 35° ≤  θ  ≤ 40° and 2 oktas ≤  ρ  ≤ 3 oktas.

A novel autonomous real-time position method based on polarized light and geomagnetic field.

PubMed

Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

2015-04-08

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

A novel autonomous real-time position method based on polarized light and geomagnetic field

PubMed Central

Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

2015-01-01

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance. PMID:25851793

A novel autonomous real-time position method based on polarized light and geomagnetic field

NASA Astrophysics Data System (ADS)

Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

2015-04-01

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

An analysis on combined GPS/COMPASS data quality and its effect on single point positioning accuracy under different observing conditions

NASA Astrophysics Data System (ADS)

Cai, Changsheng; Gao, Yang; Pan, Lin; Dai, Wujiao

2014-09-01

With the rapid development of the COMPASS system, it is currently capable of providing regional navigation services. In order to test its data quality and performance for single point positioning (SPP), experiments have been conducted under different observing conditions including open sky, under trees, nearby a glass wall, nearby a large area of water, under high-voltage lines and under a signal transmitting tower. To assess the COMPASS data quality, the code multipath, cycle slip occurrence rate and data availability were analyzed and compared to GPS data. The datasets obtained from the experiments have also been utilized to perform combined GPS/COMPASS SPP on an epoch-by-epoch basis using unsmoothed single-frequency code observations. The investigation on the regional navigation performance aims at low-accuracy applications and all tests are made in Changsha, China, using the “SOUTH S82-C” GPS/COMPASS receivers. The results show that adding COMPASS observations can significantly improve the positioning accuracy of single-frequency GPS-only SPP in environments with limited satellite visibility. Since the COMPASS system is still in an initial operational stage, all results are obtained based on a fairly limited amount of data.

Design and Calibration of a Novel Bio-Inspired Pixelated Polarized Light Compass.

PubMed

Han, Guoliang; Hu, Xiaoping; Lian, Junxiang; He, Xiaofeng; Zhang, Lilian; Wang, Yujie; Dong, Fengliang

2017-11-14

Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD) camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0 . 15 ∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation.

Design and Calibration of a Novel Bio-Inspired Pixelated Polarized Light Compass

PubMed Central

Hu, Xiaoping; Lian, Junxiang; He, Xiaofeng; Zhang, Lilian; Wang, Yujie; Dong, Fengliang

2017-01-01

Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD) camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0.15∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation. PMID:29135927

DNA Compass: a secure, client-side site for navigating personal genetic information

PubMed Central

Curnin, Charles; Gordon, Assaf; Erlich, Yaniv

2017-01-01

Abstract Motivation: Millions of individuals have access to raw genomic data using direct-to-consumer companies. The advent of large-scale sequencing projects, such as the Precision Medicine Initiative, will further increase the number of individuals with access to their own genomic information. However, querying genomic data requires a computer terminal and computational skill to analyze the data—an impediment for the general public. Results: DNA Compass is a website designed to empower the public by enabling simple navigation of personal genomic data. Users can query the status of their genomic variants for over 1658 markers or tens of millions of documented single nucleotide polymorphisms (SNPs). DNA Compass presents the relevant genotypes of the user side-by-side with explanatory scientific resources. The genotype data never leaves the user’s computer, a feature that provides improved security and performance. More than 12 000 unique users, mainly from the general genetic genealogy community, have already used DNA Compass, demonstrating its utility. Availability and Implementation: DNA Compass is freely available on https://compass.dna.land. Contact: yaniv@cs.columbia.edu PMID:28334237

A Simplified Baseband Prefilter Model with Adaptive Kalman Filter for Ultra-Tight COMPASS/INS Integration

PubMed Central

Luo, Yong; Wu, Wenqi; Babu, Ravindra; Tang, Kanghua; Luo, Bing

2012-01-01

COMPASS is an indigenously developed Chinese global navigation satellite system and will share many features in common with GPS (Global Positioning System). Since the ultra-tight GPS/INS (Inertial Navigation System) integration shows its advantage over independent GPS receivers in many scenarios, the federated ultra-tight COMPASS/INS integration has been investigated in this paper, particularly, by proposing a simplified prefilter model. Compared with a traditional prefilter model, the state space of this simplified system contains only carrier phase, carrier frequency and carrier frequency rate tracking errors. A two-quadrant arctangent discriminator output is used as a measurement. Since the code tracking error related parameters were excluded from the state space of traditional prefilter models, the code/carrier divergence would destroy the carrier tracking process, and therefore an adaptive Kalman filter algorithm tuning process noise covariance matrix based on state correction sequence was incorporated to compensate for the divergence. The federated ultra-tight COMPASS/INS integration was implemented with a hardware COMPASS intermediate frequency (IF), and INS's accelerometers and gyroscopes signal sampling system. Field and simulation test results showed almost similar tracking and navigation performances for both the traditional prefilter model and the proposed system; however, the latter largely decreased the computational load. PMID:23012564

Design of a device for sky light polarization measurements.

PubMed

Wang, Yujie; Hu, Xiaoping; Lian, Junxiang; Zhang, Lilian; Xian, Zhiwen; Ma, Tao

2014-08-14

Sky polarization patterns can be used both as indicators of atmospheric turbidity and as a sun compass for navigation. The objective of this study is to improve the precision of sky light polarization measurements by optimal design of the device used. The central part of the system is composed of a Charge Coupled Device (CCD) camera; a fish-eye lens and a linear polarizer. Algorithms for estimating parameters of the polarized light based on three images are derived and the optimal alignments of the polarizer are analyzed. The least-squares estimation is introduced for sky light polarization pattern measurement. The polarization patterns of sky light are obtained using the designed system and they follow almost the same patterns of the single-scattering Rayleigh model. Deviations of polarization angles between observation and the theory are analyzed. The largest deviations occur near the sun and anti-sun directions. Ninety percent of the deviations are less than 5° and 40% percent of them are less than 1°. The deviations decrease evidently as the degree of polarization increases. It also shows that the polarization pattern of the cloudy sky is almost identical as in the blue sky.

Design of a Device for Sky Light Polarization Measurements

PubMed Central

Wang, Yujie; Hu, Xiaoping; Lian, Junxiang; Zhang, Lilian; Xian, Zhiwen; Ma, Tao

2014-01-01

Sky polarization patterns can be used both as indicators of atmospheric turbidity and as a sun compass for navigation. The objective of this study is to improve the precision of sky light polarization measurements by optimal design of the device used. The central part of the system is composed of a Charge Coupled Device (CCD) camera; a fish-eye lens and a linear polarizer. Algorithms for estimating parameters of the polarized light based on three images are derived and the optimal alignments of the polarizer are analyzed. The least-squares estimation is introduced for sky light polarization pattern measurement. The polarization patterns of sky light are obtained using the designed system and they follow almost the same patterns of the single-scattering Rayleigh model. Deviations of polarization angles between observation and the theory are analyzed. The largest deviations occur near the sun and anti-sun directions. Ninety percent of the deviations are less than 5° and 40% percent of them are less than 1°. The deviations decrease evidently as the degree of polarization increases. It also shows that the polarization pattern of the cloudy sky is almost identical as in the blue sky. PMID:25196003

14 CFR 25.1303 - Flight and navigation instruments.

Code of Federal Regulations, 2012 CFR

2012-01-01

... indicator (nonstabilized magnetic compass). (b) The following flight and navigation instruments must be... (gyroscopically stabilized, magnetic or nonmagnetic). (c) The following flight and navigation instruments are... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Flight and navigation instruments. 25.1303...

14 CFR 25.1303 - Flight and navigation instruments.

Code of Federal Regulations, 2013 CFR

2013-01-01

... indicator (nonstabilized magnetic compass). (b) The following flight and navigation instruments must be... (gyroscopically stabilized, magnetic or nonmagnetic). (c) The following flight and navigation instruments are... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flight and navigation instruments. 25.1303...

The Art of Teaching Map and Compass: Instructional Techniques, Curricular Formats and Practical Field Exercises.

ERIC Educational Resources Information Center

Watters, Ron

This paper discusses the value of teaching map and compass skills in the classroom or an outdoor situation. Navigation is the most basic of all outdoor skills. A map and compass curriculum can be taught to anyone, is inexpensive, and is easily incorporated in a variety of educational situations. General teaching principles are outlined: (1) start…

Sensory basis of lepidopteran migration: Focus on the monarch butterfly

PubMed Central

Guerra, Patrick A.; Reppert, Steven M.

2015-01-01

In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compasses and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. PMID:25625216

Sensory basis of lepidopteran migration: focus on the monarch butterfly.

PubMed

Guerra, Patrick A; Reppert, Steven M

2015-10-01

In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compass and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

Kilohoku Ho`okele Wa`a : Astronomy of the Hawaiian Navigators

NASA Astrophysics Data System (ADS)

Slater, Stephanie; Slater, Timothy F.; Baybayan, Kalepa C.

2016-01-01

This poster provides an introduction to the astronomy of the Hawaiian wayfinders, Kilohoku Ho`okele Wa`a. Rooted in a legacy of navigation across the Polynesian triangle, wayfinding astronomy has been part of a suite of skills that allows navigators to deliberately hop between the small islands of the Pacific, for thousands of years. Forty years ago, in one manifestation of the Hawaiian Renaissance, our teachers demonstrated that ancient Hawaiians were capable of traversing the wide Pacific to settle and trade on islands separated by thousands of miles. Today those same mentors train a new generation of navigators, making Hawaiian voyaging a living, evolving, sustainable endeavor. This poster presents two components of astronomical knowledge that all crewmen, but particularly those in training to become navigators, learn early in their training. Na Ohana Hoku, the Hawaiian Star Families constitute the basic units of the Hawaiian sky. In contrast to the Western system of 88 constellations, Na Ohana Hoku divides the sky into four sections that each run from the northern to the southern poles. This configuration reduces cognitive load, allowing the navigator to preserve working memory for other complex tasks. In addition, these configurations of stars support the navigator in finding and generatively using hundreds of individual, and navigationally important pairs of stars. The Hawaiian Star Compass divides the celestial sphere into a directional system that uses 32 rather than 8 cardinal points. Within the tropics, the rising and setting of celestial objects are consistent within the Hawaiian Star Compass, providing for extremely reliable direction finding. Together, Na Ohana Hoku and the Hawaiian Star Compass provide the tropical navigator with astronomical assistance that is not available to, and would have been unknown to Western navigators trained at higher latitudes.

Maps and navigation methods

NASA Technical Reports Server (NTRS)

Duval, A

1922-01-01

Different maps and scales are discussed with particular emphasis on their use in aviation. The author makes the observation that current navigation methods are slow and dangerous and should be replaced by scientific methods of navigation based on loxodromy and the use of the compass.

Spectral properties of identified polarized-light sensitive interneurons in the brain of the desert locust Schistocerca gregaria.

PubMed

Kinoshita, Michiyo; Pfeiffer, Keram; Homberg, Uwe

2007-04-01

Many migrating animals employ a celestial compass mechanism for spatial navigation. Behavioral experiments in bees and ants have shown that sun compass navigation may rely on the spectral gradient in the sky as well as on the pattern of sky polarization. While polarized-light sensitive interneurons (POL neurons) have been identified in the brain of several insect species, there are at present no data on the neural basis of coding the spectral gradient of the sky. In the present study we have analyzed the chromatic properties of two identified POL neurons in the brain of the desert locust. Both neurons, termed TuTu1 and LoTu1, arborize in the anterior optic tubercle and respond to unpolarized light as well as to polarized light. We show here that the polarized-light response of both types of neuron relies on blue-sensitive photoreceptors. Responses to unpolarized light depended on stimulus position and wavelength. Dorsal unpolarized blue light inhibited the neurons, while stimulation from the ipsilateral side resulted in opponent responses to UV light and green light. While LoTu1 was inhibited by UV light and was excited by green light, one subtype of TuTu1 was excited by UV and inhibited by green light. In LoTu1 the sensitivity to polarized light was at least 2 log units higher than the response to unpolarized light stimuli. Taken together, the spatial and chromatic properties of the neurons may be suited to signal azimuthal directions based on a combination of the spectral gradient and the polarization pattern of the sky.

Moon orientation in adult and young sandhoppers under artificial light.

PubMed

Ugolini, Alberto; Boddi, Vieri; Mercatelli, Luca; Castellini, Carlo

2005-10-22

Our experiments, carried out at night and during the day on adults and laboratory-born young of the sandhopper Talitrus saltator, deal with the identification and use of the moon as an orientating factor. Sandhoppers were released in an apparatus (a Plexiglas dome) that produced a scenario similar to the natural one (with artificial sky, moon or sun illuminated at different intensities). When tested at night, the adult and young sandhoppers used the artificial moon like the natural one, independently of the intensity of illumination of the artificial sky and moon. In other words, sandhoppers tested at night always identified the artificial moon as the moon and never as the sun. In daytime releases, the seaward orientation failed at low intensities of artificial sky and sun illumination (3.07 and 1.55 microW cm2, respectively), whereas the sun compass was used effectively at higher levels of artificial sun and sky illumination. The innate ability of moon compass orientation in inexpert young sandhoppers was demonstrated even under artificial light.

Technologies Old and New: Teaching Ancient Navigation.

ERIC Educational Resources Information Center

Spalding, Simon

1995-01-01

One educator presents maritime history to students using technologies available to ancient seafarers. Techniques include dead reckoning, the sandglass, the magnetic compass, celestial navigation, and various navigation techniques of precontact Polynesia that depended upon oral transmission of knowledge. The paper notes differences between…

Kilohoku Ho`okele Wa`a : Astronomy of the Modern Hawaiian Wayfinders

NASA Astrophysics Data System (ADS)

Ha`o, Celeste; Dye, Ahia G.; Slater, Stephanie J.; Slater, Timothy F.; Baybayan, Kalepa

2015-08-01

This paper provides an introduction to Kilohoku Ho`okele Wa`a, the astronomy of the Hawaiian wayfinders. Rooted in a legacy of navigation across the Polynesian triangle, wayfinding astronomy has been part of a suite of skills that allows navigators to deliberately hop between the small islands of the Pacific, for thousands of years. Forty years ago, in one manifestation of the Hawaiian Renaissance, our teachers demonstrated that ancient Hawaiians were capable of traversing the wide Pacific to settle and trade on islands separated by thousands of miles. Today those same mentors train a new generation of navigators, making Hawaiian voyaging a living, evolving, sustainable endeavor. This paper presents two components of astronomical knowledge that all crewmen, but particularly those in training to become navigators, learn early in their training. Na Ohana Hoku, the Hawaiian Star Families constitute the basic units of the Hawaiian sky. In contrast to the Western system of 88 constellations, Na Ohana Hoku divides the sky into four sections that each run from the northern to the southern poles. This configuration reduces cognitive load, allowing the navigator to preserve working memory for other complex tasks. In addition, these configurations of stars support the navigator in finding and generatively using hundreds of individual, and navigationally important pairs of stars. The Hawaiian Star Compass divides the celestial sphere into a directional system that uses 32 rather than 8 cardinal points. Within the tropics, the rising and setting of celestial objects are consistent within the Hawaiian Star Compass, providing for extremely reliable direction finding. Together, Na Ohana Hoku and the Hawaiian Star Compass provide the tropical navigator with astronomical assistance that is not available to, and would have been unknown to Western navigators trained at higher latitudes.

Passive optical sensing of atmospheric polarization for GPS denied operations

NASA Astrophysics Data System (ADS)

Aycock, Todd; Lompado, Art; Wolz, Troy; Chenault, David

2016-05-01

There is a rapidly growing need for position, navigation, and timing (PNT) capability that remains effective when GPS is degraded or denied. Naturally occurring sky polarization was used as long ago as the Vikings for navigation purposes. With current polarimetric sensors, the additional polarization information measured by these sensors can be used to increase the accuracy and the availability of this technique. The Sky Polarization Azimuth Sensing System (SkyPASS) sensor measures this naturally occurring sky polarization to give absolute heading information to less than 0.1° and offers significant performance enhancement over digital compasses and sun sensors. SkyPASS has been under development for some time for terrestrial applications, but use above the atmosphere may be possible and the performance specifications and SWAP are attractive for use as an additional pose sensor on a satellite. In this paper, we will describe the phenomenology, the sensor performance, and the latest test results of terrestrial SkyPASS; we will also discuss the potential for use above the atmosphere and the expected benefits and limitations.

Polarized light sensitivity and orientation in coral reef fish post-larvae.

PubMed

Berenshtein, Igal; Kiflawi, Moshe; Shashar, Nadav; Wieler, Uri; Agiv, Haim; Paris, Claire B

2014-01-01

Recent studies of the larvae of coral-reef fishes reveal that these tiny vertebrates possess remarkable swimming capabilities, as well as the ability to orient to olfactory, auditory, and visual cues. While navigation according to reef-generated chemicals and sounds can significantly affect dispersal, the effect is limited to the vicinity of the reef. Effective long-distance navigation requires at least one other capacity-the ability to maintain a bearing using, for example, a sun compass. Directional information in the sun's position can take the form of polarized-light related cues (i.e., e-vector orientation and percent polarization) and/or non-polarized-light related cues (i.e., the direct image of the sun, and the brightness and spectral gradients). We examined the response to both types of cues using commercially-reared post-larvae of the spine-cheeked anemonefish Premnas biaculeatus. Initial optomotor trials indicated that the post-larval stages are sensitive to linearly polarized light. Swimming directionality was then tested using a Drifting In-Situ Chamber (DISC), which allowed us to examine the response of the post-larvae to natural variation in light conditions and to manipulated levels of light polarization. Under natural light conditions, 28 of 29 post-larvae showed significant directional swimming (Rayleigh's test p<0.05, R = 0.74±0.23), but to no particular direction. Swimming directionality was positively affected by sky clarity (absence of clouds and haze), which explained 38% of the observed variation. Moreover, post-larvae swimming under fully polarized light exhibited a distinct behavior of tracking the polarization axis, as it rotated along with the DISC. This behavior was not observed under partially-polarized illumination. We view these findings as an indication for the use of sun-related cues, and polarized light signal in specific, by orienting coral-reef fish larvae.

14 CFR Appendix A to Part 141 - Recreational Pilot Certification Course

Code of Federal Regulations, 2012 CFR

2012-01-01

... navigation using pilotage with the aid of a magnetic compass; (e) Recognition of critical weather situations...) Ground reference maneuvers; (vii) Navigation; (viii) Slow flight and stalls; (ix) Emergency operations..., and go-arounds; (vi) Performance maneuvers; (vii) Navigation; (viii) Emergency operations; and (ix...

The installation and correction of compasses in airplanes

NASA Technical Reports Server (NTRS)

Schoeffel, M F

1927-01-01

The saving of time that results from flying across country on compass headings is beginning to be widely recognized. At the same time the general use of steel tube fuselages has made a knowledge of compass correction much more necessary than was the case when wooden fuselages were the rule. This paper has been prepared primarily for the benefit of the pilot who has never studied navigation and who does not desire to go into the subject more deeply than to be able to fly compass courses with confidence. It also contains material for the designer who wishes to install his compasses with the expectation that they may be accurately corrected.

14 CFR 121.420 - Flight navigators: Initial and transition ground training.

Code of Federal Regulations, 2014 CFR

2014-01-01

... indicating instruments or systems. (5) Compass limitations and methods of compensation. (6) Cruise control..., cruise, and descent speeds. (2) Each item of navigational equipment installed including appropriate radio...

46 CFR 185.220 - Records of a voyage resulting in a marine casualty.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, stowage plans... passenger lists and counts, articles of shipment, official logs, and other material that might be of...

Quartermaster 1 and C, Rate Training Manual.

ERIC Educational Resources Information Center

Naval Personnel Program Support Activity, Washington, DC.

The subject matter of this training manual is prepared for regular navy and naval reserve personnel. Operations of gyrocompasses and magnetic and magnesyn compasses are discussed with a background of error determination, compass adjustments, and degaussing applications. Navigation techniques are analyzed in terms of piloting, dead reckoning,…

Developing Navigational Skills with Young Children: Investigating Serial and Conceptual Approaches to the Teaching of Compass Skills. Sports Science Education Programme, Annual Report 1989/90.

ERIC Educational Resources Information Center

Liverpool Univ. (England).

Map and compass skills are a neglected aspect of the elementary school curriculum. Orienteering--a sport that involves running a prescribed course with the aid of map and compass--may provide an avenue for teaching these skills. This study taught orienteering to 148 10-year-old children and compared the effectiveness of a serial approach based on…

The Radical Pair Mechanism and the Avian Chemical Compass: Quantum Coherence and Entanglement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yiteng; Kais, Sabre; Berman, Gennady Petrovich

2015-02-02

We review the spin radical pair mechanism which is a promising explanation of avian navigation. This mechanism is based on the dependence of product yields on 1) the hyperfine interaction involving electron spins and neighboring nuclear spins and 2) the intensity and orientation of the geomagnetic field. One surprising result is that even at ambient conditions quantum entanglement of electron spins can play an important role in avian magnetoreception. This review describes the general scheme of chemical reactions involving radical pairs generated from singlet and triplet precursors; the spin dynamics of the radical pairs; and the magnetic field dependence ofmore » product yields caused by the radical pair mechanism. The main part of the review includes a description of the chemical compass in birds. We review: the general properties of the avian compass; the basic scheme of the radical pair mechanism; the reaction kinetics in cryptochrome; quantum coherence and entanglement in the avian compass; and the effects of noise. We believe that the quantum avian compass can play an important role in avian navigation and can also provide the foundation for a new generation of sensitive and selective magnetic-sensing nano-devices.« less

A generic sun-tracking algorithm for on-axis solar collector in mobile platforms

NASA Astrophysics Data System (ADS)

Lai, An-Chow; Chong, Kok-Keong; Lim, Boon-Han; Ho, Ming-Cheng; Yap, See-Hao; Heng, Chun-Kit; Lee, Jer-Vui; King, Yeong-Jin

2015-04-01

This paper proposes a novel dynamic sun-tracking algorithm which allows accurate tracking of the sun for both non-concentrated and concentrated photovoltaic systems located on mobile platforms to maximize solar energy extraction. The proposed algorithm takes not only the date, time, and geographical information, but also the dynamic changes of coordinates of the mobile platforms into account to calculate the sun position angle relative to ideal azimuth-elevation axes in real time using general sun-tracking formulas derived by Chong and Wong. The algorithm acquires data from open-loop sensors, i.e. global position system (GPS) and digital compass, which are readily available in many off-the-shelf portable gadgets, such as smart phone, to instantly capture the dynamic changes of coordinates of mobile platforms. Our experiments found that a highly accurate GPS is not necessary as the coordinate changes of practical mobile platforms are not fast enough to produce significant differences in the calculation of the incident angle. On the contrary, it is critical to accurately identify the quadrant and angle where the mobile platforms are moving toward in real time, which can be resolved by using digital compass. In our implementation, a noise filtering mechanism is found necessary to remove unexpected spikes in the readings of the digital compass to ensure stability in motor actuations and effectiveness in continuous tracking. Filtering mechanisms being studied include simple moving average and linear regression; the results showed that a compound function of simple moving average and linear regression produces a better outcome. Meanwhile, we found that a sampling interval is useful to avoid excessive motor actuations and power consumption while not sacrificing the accuracy of sun-tracking.

Polarised skylight and the landmark panorama provide night-active bull ants with compass information during route following.

PubMed

Reid, Samuel F; Narendra, Ajay; Hemmi, Jan M; Zeil, Jochen

2011-02-01

Navigating animals are known to use a number of celestial and terrestrial compass cues that allow them to determine and control their direction of travel. Which of the cues dominate appears to depend on their salience. Here we show that night-active bull ants attend to both the pattern of polarised skylight and the landmark panorama in their familiar habitat. When the two directional cues are in conflict, ants choose a compromise direction. However, landmark guidance appears to be the primary mechanism of navigation used by forager ants, with those cues in the direction of heading having the greatest influence on navigation. Different colonies respond to the removal of these cues to different degrees, depending on the directional information provided by the local landmark panorama. Interestingly, other parts of the surrounding panorama also influence foraging speed and accuracy, suggesting that they too play a role in navigation.

The case for long range chemoreceptive piloting in Chelonia

NASA Technical Reports Server (NTRS)

Carr, A. F., Jr.

1972-01-01

The reproductive ecology and migration habits of Chelonia are investigated. Efforts were made to determine if the turtle navigates by chemoreception and if sensory responses of the migrating animals could be electronically tracked through telemetry. Efforts were also made to: (1) explain why certain small islands or restricted areas of mainland shore are chosen by Chelonia as nesting grounds, even when located a thousand miles or more from the year round feeding grounds of the population; (2) identify guidance mechanisms used by migrants in their periodic open ocean travels; and (3) account for the so called lost year - the virtually complete disappearance of young sea turtles during their first year of life. It was suggested that turtle migration is aided by an olfactory mechanism, sun compass, and ocean currents. The tracking experiment was unsuccessful; the equipment was lost or damaged and stopped functioning after about two hours.

Magnetic compasses in insects

USDA-ARS?s Scientific Manuscript database

The use of magnetic information for orientation and navigation is a widespread phenomenon in animals. In contrast to navigational systems in vertebrates, our understanding of the mechanisms underlying the insect magnetic perception and use of the information is at an early stage. Some insects use ma...

Individual Global Navigation Satellite Systems in the Space Service Volume

NASA Technical Reports Server (NTRS)

Force, Dale A.

2013-01-01

The use of individual Global Navigation Satellite Services (GPS, GLONASS, Galileo, and Beidou/COMPASS) for the position, navigation, and timing in the Space Service Volume at altitudes of 300 km, 3000 km, 8000 km, 15000 km, 25000 km, 36500km and 70000 km is examined and the percent availability of at least one and at least four satellites is presented.

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.

Code of Federal Regulations, 2014 CFR

2014-07-01

... magnetic steering compass readable from the vessel's main steering station, if the vessel engages in towing... engages in towing on navigable waters of the U.S., including Western Rivers, the radar must meet— (A) The... than 300 tons gross tonnage that engages in towing seaward of navigable waters of the U.S. or more than...

33 CFR 164.72 - Navigational-safety equipment, charts or maps, and publications required on towing vessels.

Code of Federal Regulations, 2013 CFR

2013-07-01

... magnetic steering compass readable from the vessel's main steering station, if the vessel engages in towing... engages in towing on navigable waters of the U.S., including Western Rivers, the radar must meet— (A) The... than 300 tons gross tonnage that engages in towing seaward of navigable waters of the U.S. or more than...

46 CFR 169.807 - Notice of casualty.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the vessel's seaworthiness or fitness for service or route, including but not limited to fire... of the vessel involved, the name of the vessel's owner or agent, nature, location and circumstances..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, record of draft, aids...

46 CFR 169.807 - Notice of casualty.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the vessel's seaworthiness or fitness for service or route, including but not limited to fire... of the vessel involved, the name of the vessel's owner or agent, nature, location and circumstances..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, record of draft, aids...

46 CFR 169.807 - Notice of casualty.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the vessel's seaworthiness or fitness for service or route, including but not limited to fire... of the vessel involved, the name of the vessel's owner or agent, nature, location and circumstances..., navigation charts, navigation work books, compass deviation cards, gyrocompass records, record of draft, aids...

Polarized Light Sensitivity and Orientation in Coral Reef Fish Post-Larvae

PubMed Central

Berenshtein, Igal; Kiflawi, Moshe; Shashar, Nadav; Wieler, Uri; Agiv, Haim; Paris, Claire B.

2014-01-01

Recent studies of the larvae of coral-reef fishes reveal that these tiny vertebrates possess remarkable swimming capabilities, as well as the ability to orient to olfactory, auditory, and visual cues. While navigation according to reef-generated chemicals and sounds can significantly affect dispersal, the effect is limited to the vicinity of the reef. Effective long-distance navigation requires at least one other capacity–the ability to maintain a bearing using, for example, a sun compass. Directional information in the sun’s position can take the form of polarized-light related cues (i.e., e-vector orientation and percent polarization) and/or non-polarized-light related cues (i.e., the direct image of the sun, and the brightness and spectral gradients). We examined the response to both types of cues using commercially-reared post-larvae of the spine-cheeked anemonefish Premnas biaculeatus. Initial optomotor trials indicated that the post-larval stages are sensitive to linearly polarized light. Swimming directionality was then tested using a Drifting In-Situ Chamber (DISC), which allowed us to examine the response of the post-larvae to natural variation in light conditions and to manipulated levels of light polarization. Under natural light conditions, 28 of 29 post-larvae showed significant directional swimming (Rayleigh’s test p<0.05, R = 0.74±0.23), but to no particular direction. Swimming directionality was positively affected by sky clarity (absence of clouds and haze), which explained 38% of the observed variation. Moreover, post-larvae swimming under fully polarized light exhibited a distinct behavior of tracking the polarization axis, as it rotated along with the DISC. This behavior was not observed under partially-polarized illumination. We view these findings as an indication for the use of sun-related cues, and polarized light signal in specific, by orienting coral-reef fish larvae. PMID:24516662

Gilbert [Gilberd], William (1544-1603)

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

Doctor and scientist, born in Colchester, England, wrote De Magnete (On the Magnet), published in 1600. The magnetic compass was one of most useful the navigational instruments before the chronometer, but little was known about the lodestone (magnetic iron ore). Gilbert made his own experiments, such as testing the folk-belief that garlic destroys the magnetic effect of the compass needle. He dra...

How to find home backwards? Navigation during rearward homing of Cataglyphis fortis desert ants.

PubMed

Pfeffer, Sarah E; Wittlinger, Matthias

2016-07-15

Cataglyphis ants are renowned for their impressive navigation skills, which have been studied in numerous experiments during forward locomotion. However, the ants' navigational performance during backward homing when dragging large food loads has not been investigated until now. During backward locomotion, the odometer has to deal with unsteady motion and irregularities in inter-leg coordination. The legs' sensory feedback during backward walking is not just a simple reversal of the forward stepping movements: compared with forward homing, ants are facing towards the opposite direction during backward dragging. Hence, the compass system has to cope with a flipped celestial view (in terms of the polarization pattern and the position of the sun) and an inverted retinotopic image of the visual panorama and landmark environment. The same is true for wind and olfactory cues. In this study we analyze for the first time backward-homing ants and evaluate their navigational performance in channel and open field experiments. Backward-homing Cataglyphis fortis desert ants show remarkable similarities in the performance of homing compared with forward-walking ants. Despite the numerous challenges emerging for the navigational system during backward walking, we show that ants perform quite well in our experiments. Direction and distance gauging was comparable to that of the forward-walking control groups. Interestingly, we found that backward-homing ants often put down the food item and performed foodless search loops around the left food item. These search loops were mainly centred around the drop-off position (and not around the nest position), and increased in length the closer the ants came to their fictive nest site. © 2016. Published by The Company of Biologists Ltd.

46 CFR 4.05-15 - Voyage records, retention of.

Code of Federal Regulations, 2010 CFR

2010-10-01

... room logs, bell books, navigation charts, navigation work books, compass deviation cards, gyro records, stowage plans, records of draft, aids to mariners, night order books, radiograms sent and received, radio... request, to a duly authorized investigating officer, administrative law judge, officer or employee of the...

A Bionic Polarization Navigation Sensor and Its Calibration Method.

PubMed

Zhao, Huijie; Xu, Wujian

2016-08-03

The polarization patterns of skylight which arise due to the scattering of sunlight in the atmosphere can be used by many insects for deriving compass information. Inspired by insects' polarized light compass, scientists have developed a new kind of navigation method. One of the key techniques in this method is the polarimetric sensor which is used to acquire direction information from skylight. In this paper, a polarization navigation sensor is proposed which imitates the working principles of the polarization vision systems of insects. We introduce the optical design and mathematical model of the sensor. In addition, a calibration method based on variable substitution and non-linear curve fitting is proposed. The results obtained from the outdoor experiments provide support for the feasibility and precision of the sensor. The sensor's signal processing can be well described using our mathematical model. A relatively high degree of accuracy in polarization measurement can be obtained without any error compensation.

A Bionic Polarization Navigation Sensor and Its Calibration Method

PubMed Central

Zhao, Huijie; Xu, Wujian

2016-01-01

The polarization patterns of skylight which arise due to the scattering of sunlight in the atmosphere can be used by many insects for deriving compass information. Inspired by insects’ polarized light compass, scientists have developed a new kind of navigation method. One of the key techniques in this method is the polarimetric sensor which is used to acquire direction information from skylight. In this paper, a polarization navigation sensor is proposed which imitates the working principles of the polarization vision systems of insects. We introduce the optical design and mathematical model of the sensor. In addition, a calibration method based on variable substitution and non-linear curve fitting is proposed. The results obtained from the outdoor experiments provide support for the feasibility and precision of the sensor. The sensor’s signal processing can be well described using our mathematical model. A relatively high degree of accuracy in polarization measurement can be obtained without any error compensation. PMID:27527171

Transmedulla Neurons in the Sky Compass Network of the Honeybee (Apis mellifera) Are a Possible Site of Circadian Input.

PubMed

Zeller, Maximilian; Held, Martina; Bender, Julia; Berz, Annuska; Heinloth, Tanja; Hellfritz, Timm; Pfeiffer, Keram

2015-01-01

Honeybees are known for their ability to use the sun's azimuth and the sky's polarization pattern for spatial orientation. Sky compass orientation in bees has been extensively studied at the behavioral level but our knowledge about the underlying neuronal systems and mechanisms is very limited. Electrophysiological studies in other insect species suggest that neurons of the sky compass system integrate information about the polarization pattern of the sky, its chromatic gradient, and the azimuth of the sun. In order to obtain a stable directional signal throughout the day, circadian changes between the sky polarization pattern and the solar azimuth must be compensated. Likewise, the system must be modulated in a context specific way to compensate for changes in intensity, polarization and chromatic properties of light caused by clouds, vegetation and landscape. The goal of this study was to identify neurons of the sky compass pathway in the honeybee brain and to find potential sites of circadian and neuromodulatory input into this pathway. To this end we first traced the sky compass pathway from the polarization-sensitive dorsal rim area of the compound eye via the medulla and the anterior optic tubercle to the lateral complex using dye injections. Neurons forming this pathway strongly resembled neurons of the sky compass pathway in other insect species. Next we combined tracer injections with immunocytochemistry against the circadian neuropeptide pigment dispersing factor and the neuromodulators serotonin, and γ-aminobutyric acid. We identified neurons, connecting the dorsal rim area of the medulla to the anterior optic tubercle, as a possible site of neuromodulation and interaction with the circadian system. These neurons have conspicuous spines in close proximity to pigment dispersing factor-, serotonin-, and GABA-immunoreactive neurons. Our data therefore show for the first time a potential interaction site between the sky compass pathway and the circadian clock.

Diurnal dung beetles use the intensity gradient and the polarization pattern of the sky for orientation.

PubMed

el Jundi, Basil; Smolka, Jochen; Baird, Emily; Byrne, Marcus J; Dacke, Marie

2014-07-01

To escape competition at the dung pile, a ball-rolling dung beetle forms a piece of dung into a ball and rolls it away. To ensure their efficient escape from the dung pile, beetles rely on a 'celestial compass' to move along a straight path. Here, we analyzed the reliability of different skylight cues for this compass and found that dung beetles rely not only on the sun but also on the skylight polarization pattern. Moreover, we show the first evidence of an insect using the celestial light-intensity gradient for orientation. Using a polarizer, we manipulated skylight so that the polarization pattern appeared to turn by 90 deg. The beetles then changed their bearing close to the expected 90 deg. This behavior was abolished if the sun was visible to the beetle, suggesting that polarized light is hierarchically subordinate to the sun. When the sky was depolarized and the sun was invisible, the beetles could still move along straight paths. Therefore, we analyzed the use of the celestial light-intensity gradient for orientation. Artificial rotation of the intensity pattern by 180 deg caused beetles to orient in the opposite direction. This light-intensity cue was also found to be subordinate to the sun and could play a role in disambiguating the polarization signal, especially at low sun elevations. © 2014. Published by The Company of Biologists Ltd.

Neural coding underlying the cue preference for celestial orientation

PubMed Central

el Jundi, Basil; Warrant, Eric J.; Byrne, Marcus J.; Khaldy, Lana; Baird, Emily; Smolka, Jochen; Dacke, Marie

2015-01-01

Diurnal and nocturnal African dung beetles use celestial cues, such as the sun, the moon, and the polarization pattern, to roll dung balls along straight paths across the savanna. Although nocturnal beetles move in the same manner through the same environment as their diurnal relatives, they do so when light conditions are at least 1 million-fold dimmer. Here, we show, for the first time to our knowledge, that the celestial cue preference differs between nocturnal and diurnal beetles in a manner that reflects their contrasting visual ecologies. We also demonstrate how these cue preferences are reflected in the activity of compass neurons in the brain. At night, polarized skylight is the dominant orientation cue for nocturnal beetles. However, if we coerce them to roll during the day, they instead use a celestial body (the sun) as their primary orientation cue. Diurnal beetles, however, persist in using a celestial body for their compass, day or night. Compass neurons in the central complex of diurnal beetles are tuned only to the sun, whereas the same neurons in the nocturnal species switch exclusively to polarized light at lunar light intensities. Thus, these neurons encode the preferences for particular celestial cues and alter their weighting according to ambient light conditions. This flexible encoding of celestial cue preferences relative to the prevailing visual scenery provides a simple, yet effective, mechanism for enabling visual orientation at any light intensity. PMID:26305929

Neural coding underlying the cue preference for celestial orientation.

PubMed

el Jundi, Basil; Warrant, Eric J; Byrne, Marcus J; Khaldy, Lana; Baird, Emily; Smolka, Jochen; Dacke, Marie

2015-09-08

Diurnal and nocturnal African dung beetles use celestial cues, such as the sun, the moon, and the polarization pattern, to roll dung balls along straight paths across the savanna. Although nocturnal beetles move in the same manner through the same environment as their diurnal relatives, they do so when light conditions are at least 1 million-fold dimmer. Here, we show, for the first time to our knowledge, that the celestial cue preference differs between nocturnal and diurnal beetles in a manner that reflects their contrasting visual ecologies. We also demonstrate how these cue preferences are reflected in the activity of compass neurons in the brain. At night, polarized skylight is the dominant orientation cue for nocturnal beetles. However, if we coerce them to roll during the day, they instead use a celestial body (the sun) as their primary orientation cue. Diurnal beetles, however, persist in using a celestial body for their compass, day or night. Compass neurons in the central complex of diurnal beetles are tuned only to the sun, whereas the same neurons in the nocturnal species switch exclusively to polarized light at lunar light intensities. Thus, these neurons encode the preferences for particular celestial cues and alter their weighting according to ambient light conditions. This flexible encoding of celestial cue preferences relative to the prevailing visual scenery provides a simple, yet effective, mechanism for enabling visual orientation at any light intensity.

Visual Navigation in Nocturnal Insects.

PubMed

Warrant, Eric; Dacke, Marie

2016-05-01

Despite their tiny eyes and brains, nocturnal insects have evolved a remarkable capacity to visually navigate at night. Whereas some use moonlight or the stars as celestial compass cues to maintain a straight-line course, others use visual landmarks to navigate to and from their nest. These impressive abilities rely on highly sensitive compound eyes and specialized visual processing strategies in the brain. ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

Book Review: Earth's Magnetism in the Age of Sail. A.R.T. Jonkers, The Johns Hopkins University Press, Baltimore, London, 300 pp., ISBN 0-8018-7132-8, 2003, $45 (£35)

NASA Astrophysics Data System (ADS)

Love, J. J.

2004-12-01

For many centuries, the source, behavior, and even the essential nature of geomagnetism were enigmatic. Despite this, the effect of geomagnetism was familiar, by imparting a directional preference on the magnetized needle of the compass and providing a useful, if somewhat annoyingly complicated, reference for navigators. Although the compass seems to have first been invented in China, it was the Europeans who made the most systematic early studies of magnetism, who made the first elaborate and practical usage of the compass, and who developed most of the early theories as to the cause of the compass needle's north-seeking tendency. From the centuries of the Middle Ages, through the late 16th century of the Renaissance, to the 17th century of philosophical enlightenment and the 18th century of discovery, the subject of magnetism and, more specifically, geomagnetism, evolved from a hodgepodge of mystical beliefs into something that we can today recognize as the object of modern scientific pursuit. Those same centuries witnessed the great transoceanic sailing voyages undertaken by European nations for reasons of exploration, territorial claim, religious mission, and mercantile trade. Naturally, the navigator's compass, and therefore geomagnetism, played an important role in these developments. This romantic intersection of science and history is the subject of Earth's Magnetism in the Age of Sail, a pleasantly written and scholarly book by A.R.T. Jonkers.

Precision Airdrop (Largage de precision)

DTIC Science & Technology

2005-12-01

NAVIGATION TO A PRECISION AIRDROP OVERVIEW RTO-AG-300-V24 2 - 9 the point from various compass headings. As the tests are conducted, the resultant...rate. This approach avoids including a magnetic compass for the heading reference, which has difficulties due to local changes in the magnetic field...Scientifica della Difesa ROYAUME-UNI Via XX Settembre 123 Dstl Knowledge Services ESPAGNE 00187 Roma Information Centre, Building 247 SDG TECEN / DGAM

Chasing Migration Genes: A Brain Expressed Sequence Tag Resource for Summer and Migratory Monarch Butterflies (Danaus plexippus)

PubMed Central

Zhu, Haisun; Casselman, Amy; Reppert, Steven M.

2008-01-01

North American monarch butterflies (Danaus plexippus) undergo a spectacular fall migration. In contrast to summer butterflies, migrants are juvenile hormone (JH) deficient, which leads to reproductive diapause and increased longevity. Migrants also utilize time-compensated sun compass orientation to help them navigate to their overwintering grounds. Here, we describe a brain expressed sequence tag (EST) resource to identify genes involved in migratory behaviors. A brain EST library was constructed from summer and migrating butterflies. Of 9,484 unique sequences, 6068 had positive hits with the non-redundant protein database; the EST database likely represents ∼52% of the gene-encoding potential of the monarch genome. The brain transcriptome was cataloged using Gene Ontology and compared to Drosophila. Monarch genes were well represented, including those implicated in behavior. Three genes involved in increased JH activity (allatotropin, juvenile hormone acid methyltransfersase, and takeout) were upregulated in summer butterflies, compared to migrants. The locomotion-relevant turtle gene was marginally upregulated in migrants, while the foraging and single-minded genes were not differentially regulated. Many of the genes important for the monarch circadian clock mechanism (involved in sun compass orientation) were in the EST resource, including the newly identified cryptochrome 2. The EST database also revealed a novel Na+/K+ ATPase allele predicted to be more resistant to the toxic effects of milkweed than that reported previously. Potential genetic markers were identified from 3,486 EST contigs and included 1599 double-hit single nucleotide polymorphisms (SNPs) and 98 microsatellite polymorphisms. These data provide a template of the brain transcriptome for the monarch butterfly. Our “snap-shot” analysis of the differential regulation of candidate genes between summer and migratory butterflies suggests that unbiased, comprehensive transcriptional profiling will inform the molecular basis of migration. The identified SNPs and microsatellite polymorphisms can be used as genetic markers to address questions of population and subspecies structure. PMID:18183285

Receptive fields of locust brain neurons are matched to polarization patterns of the sky.

PubMed

Bech, Miklós; Homberg, Uwe; Pfeiffer, Keram

2014-09-22

Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Polarization-sensitive descending neurons in the locust: connecting the brain to thoracic ganglia.

PubMed

Träger, Ulrike; Homberg, Uwe

2011-02-09

Many animal species, in particular insects, exploit the E-vector pattern of the blue sky for sun compass navigation. Like other insects, locusts detect dorsal polarized light via photoreceptors in a specialized dorsal rim area of the compound eye. Polarized light information is transmitted through several processing stages to the central complex, a brain area involved in the control of goal-directed orientation behavior. To investigate how polarized light information is transmitted to thoracic motor circuits, we studied the responses of locust descending neurons to polarized light. Three sets of polarization-sensitive descending neurons were characterized through intracellular recordings from axonal fibers in the neck connectives combined with single-cell dye injections. Two descending neurons from the brain, one with ipsilaterally and the second with contralaterally descending axon, are likely to bridge the gap between polarization-sensitive neurons in the brain and thoracic motor centers. In both neurons, E-vector tuning changed linearly with daytime, suggesting that they signal time-compensated spatial directions, an important prerequisite for navigation using celestial signals. The third type connects the suboesophageal ganglion with the prothoracic ganglion. It showed no evidence for time compensation in E-vector tuning and might play a role in flight stabilization and control of head movements.

The Geomagnetic Field Is a Compass Cue in Cataglyphis Ant Navigation.

PubMed

Fleischmann, Pauline Nikola; Grob, Robin; Müller, Valentin Leander; Wehner, Rüdiger; Rössler, Wolfgang

2018-05-07

Desert ants (Cataglyphis) are famous insect navigators. During their foraging lives, the ants leave their underground colonies for long distances and return to their starting point with fair accuracy [1, 2]. Their incessantly running path integrator provides them with a continually updated home vector [3-5]. Directional input to their path integrator is provided by a visual compass based on celestial cues [6, 7]. However, as path integration is prone to cumulative errors, the ants additionally employ landmark guidance routines [8-11]. At the start of their foraging lives, they acquire the necessary landmark information by performing well-structured learning walks [12, 13], including turns about their vertical body axes [14]. When Cataglyphis noda performs these pirouettes, it always gazes at the nest entrance during the longest of several short stopping phases [14]. As the small nest entrance is not visible, the ants can adjust their gaze direction only by reading out their path integrator. However, recent experiments have shown that, for adjusting the goal-centered gaze directions during learning walks, skylight cues are not required [15]. A most promising remaining compass cue is the geomagnetic field, which is used for orientation in one way or the other by a variety of animal species [16-25]. Here, we show that the gaze directions during the look-back-to-the-nest behavior change in a predictable way to alterations of the horizontal component of the magnetic field. This is the first demonstration that, in insects, a geomagnetic compass cue is both necessary and sufficient for accomplishing a well-defined navigational task. Copyright © 2018 Elsevier Ltd. All rights reserved.

Visual but not trigeminal mediation of magnetic compass information in a migratory bird.

PubMed

Zapka, Manuela; Heyers, Dominik; Hein, Christine M; Engels, Svenja; Schneider, Nils-Lasse; Hans, Jörg; Weiler, Simon; Dreyer, David; Kishkinev, Dmitry; Wild, J Martin; Mouritsen, Henrik

2009-10-29

Magnetic compass information has a key role in bird orientation, but the physiological mechanisms enabling birds to sense the Earth's magnetic field remain one of the unresolved mysteries in biology. Two biophysical mechanisms have become established as the most promising magnetodetection candidates. The iron-mineral-based hypothesis suggests that magnetic information is detected by magnetoreceptors in the upper beak and transmitted through the ophthalmic branch of the trigeminal nerve to the brain. The light-dependent hypothesis suggests that magnetic field direction is sensed by radical pair-forming photopigments in the eyes and that this visual signal is processed in cluster N, a specialized, night-time active, light-processing forebrain region. Here we report that European robins with bilateral lesions of cluster N are unable to show oriented magnetic-compass-guided behaviour but are able to perform sun compass and star compass orientation behaviour. In contrast, bilateral section of the ophthalmic branch of the trigeminal nerve in European robins did not influence the birds' ability to use their magnetic compass for orientation. These data show that cluster N is required for magnetic compass orientation in this species and indicate that it may be specifically involved in processing of magnetic compass information. Furthermore, the data strongly suggest that a vision-mediated mechanism underlies the magnetic compass in this migratory songbird, and that the putative iron-mineral-based receptors in the upper beak connected to the brain by the trigeminal nerve are neither necessary nor sufficient for magnetic compass orientation in European robins.

78 FR 5153 - Proposed Amendment of Class E Airspace; Reno, NV

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-24

... Compass Locator at the Instrument Landing System Middle Marker (LMM) and the Middle Marker (MM) has made... necessary due to the decommissioning of the LMM and the MM navigation aids. The Airport Reference Point (ARP) would be used to describe the airspace instead of the LMM and the MM navigational aids. There would be...

Inflight IFR procedures simulator

NASA Technical Reports Server (NTRS)

Parker, L. C. (Inventor)

1984-01-01

An inflight IFR procedures simulator for generating signals and commands to conventional instruments provided in an airplane is described. The simulator includes a signal synthesizer which generates predetermined simulated signals corresponding to signals normally received from remote sources upon being activated. A computer is connected to the signal synthesizer and causes the signal synthesizer to produce simulated signals responsive to programs fed into the computer. A switching network is connected to the signal synthesizer, the antenna of the aircraft, and navigational instruments and communication devices for selectively connecting instruments and devices to the synthesizer and disconnecting the antenna from the navigational instruments and communication device. Pressure transducers are connected to the altimeter and speed indicator for supplying electrical signals to the computer indicating the altitude and speed of the aircraft. A compass is connected for supply electrical signals for the computer indicating the heading of the airplane. The computer upon receiving signals from the pressure transducer and compass, computes the signals that are fed to the signal synthesizer which, in turn, generates simulated navigational signals.

A distinct layer of the medulla integrates sky compass signals in the brain of an insect.

PubMed

el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

2011-01-01

Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu.

A Distinct Layer of the Medulla Integrates Sky Compass Signals in the Brain of an Insect

PubMed Central

el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

2011-01-01

Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu. PMID:22114712

The lizard celestial compass detects linearly polarized light in the blue.

PubMed

Beltrami, Giulia; Parretta, Antonio; Petrucci, Ferruccio; Buttini, Paola; Bertolucci, Cristiano; Foà, Augusto

2012-09-15

The present study first examined whether ruin lizards, Podarcis sicula, are able to orientate using plane-polarized light produced by an LCD screen. Ruin lizards were trained and tested indoors, inside a hexagonal Morris water maze positioned under an LCD screen producing white polarized light with a single E-vector, which provided an axial cue. White polarized light did not include wavelengths in the UV. Lizards orientated correctly either when tested with E-vector parallel to the training axis or after 90 deg rotation of the E-vector direction, thus validating the apparatus. Further experiments examined whether there is a preferential region of the light spectrum to perceive the E-vector direction of polarized light. For this purpose, lizards reaching learning criteria under white polarized light were subdivided into four experimental groups. Each group was tested for orientation under a different spectrum of plane-polarized light (red, green, cyan and blue) with equalized photon flux density. Lizards tested under blue polarized light orientated correctly, whereas lizards tested under red polarized light were completely disoriented. Green polarized light was barely discernible by lizards, and thus insufficient for a correct functioning of their compass. When exposed to cyan polarized light, lizard orientation performances were optimal, indistinguishable from lizards detecting blue polarized light. Overall, the present results demonstrate that perception of linear polarization in the blue is necessary - and sufficient - for a proper functioning of the sky polarization compass of ruin lizards. This may be adaptively important, as detection of polarized light in the blue improves functioning of the polarization compass under cloudy skies, i.e. when the alternative celestial compass based on detection of the sun disk is rendered useless because the sun is obscured by clouds.

Integration of polarization and chromatic cues in the insect sky compass.

PubMed

el Jundi, Basil; Pfeiffer, Keram; Heinze, Stanley; Homberg, Uwe

2014-06-01

Animals relying on a celestial compass for spatial orientation may use the position of the sun, the chromatic or intensity gradient of the sky, the polarization pattern of the sky, or a combination of these cues as compass signals. Behavioral experiments in bees and ants, indeed, showed that direct sunlight and sky polarization play a role in sky compass orientation, but the relative importance of these cues are species-specific. Intracellular recordings from polarization-sensitive interneurons in the desert locust and monarch butterfly suggest that inputs from different eye regions, including polarized-light input through the dorsal rim area of the eye and chromatic/intensity gradient input from the main eye, are combined at the level of the medulla to create a robust compass signal. Conflicting input from the polarization and chromatic/intensity channel, resulting from eccentric receptive fields, is eliminated at the level of the anterior optic tubercle and central complex through internal compensation for changing solar elevations, which requires input from a circadian clock. Across several species, the central complex likely serves as an internal sky compass, combining E-vector information with other celestial cues. Descending neurons, likewise, respond both to zenithal polarization and to unpolarized cues in an azimuth-dependent way.

Urban, Indoor and Subterranean Navigation Sensors and Systems (Capteurs et systemes de navigation urbains, interieurs et souterrains)

DTIC Science & Technology

2010-11-01

3-10 Multiple Images of an Image Sequence Figure 3-10 A Digital Magnetic Compass from KVH Industries 3-11 Figure 3-11 Earth’s Magnetic Field 3-11...ARINO SENER – Ingenieria y Sistemas S.A Aerospace Division Parque Tecnologico de Madrid Calle Severo Ocho 4 28760 Tres Cantos Madrid Email...experts from government, academia, industry and the military produced an analysis of future navigation sensors and systems whose performance

Navigation: bat orientation using Earth's magnetic field.

PubMed

Holland, Richard A; Thorup, Kasper; Vonhof, Maarten J; Cochran, William W; Wikelski, Martin

2006-12-07

Bats famously orientate at night by echolocation, but this works over only a short range, and little is known about how they navigate over longer distances. Here we show that the homing behaviour of Eptesicus fuscus, known as the big brown bat, can be altered by artificially shifting the Earth's magnetic field, indicating that these bats rely on a magnetic compass to return to their home roost. This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark.

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2012 CFR

2012-01-01

... “Aeronautical Information Manual” and FAA advisory circulars; (4) Use of aeronautical charts for VFR navigation using pilotage with the aid of a magnetic compass; (5) Recognition of critical weather situations from...

Orientation of pigeons exposed to constant light and released from familiar sites.

PubMed

Dall'Antonia, P; Luschi, P

1993-12-01

It has been proposed that homing pigeons may use pilotage to orient home when released from familiar sites. To test this possibility, a group of pigeons was released from familiar locations after being exposed to a constant bright light. This treatment produced the loss of the circadian rhythmicity of general activity of the birds and thus presumably impaired their time-compensating sun compass mechanism. Experimental birds, both anosmic and olfactorily unimpaired, did not show any tendency to orient home, their bearing distributions being generally not different from random. Their homing performances were also affected. These results show that initial orientation of pigeons released from familiar sites entails the use of the sun compass even when the birds are released after a treatment that makes them arrhythmic in their activity. The possibility that pilotage may play a role in the first part of the homing flight of pigeons remains to be demonstrated.

Songlines and navigation in Wardaman and other Australian Aboriginal cultures

NASA Astrophysics Data System (ADS)

Norris, Ray P.; Harney, Bill Yidumdum

2014-07-01

We discuss the songlines and navigation of the Wardaman people, and place them in context by comparing them with corresponding practices in other Aboriginal Australian language groups, using previously-unpublished information and also information drawn from the literature. Songlines are effectively oral maps of the landscape, enabling the transmission of oral navigational skills in cultures that do not have a written language. In many cases, songlines on the Earth are mirrored by songlines in the sky, enabling the sky to be used as a navigational tool, both by using it as a compass and by using it as a mnemonic.

Homing of invasive Burmese pythons in South Florida: evidence for map and compass senses in snakes

PubMed Central

Pittman, Shannon E.; Hart, Kristen M.; Cherkiss, Michael S.; Snow, Ray W.; Fujisaki, Ikuko; Smith, Brian J.; Mazzotti, Frank J.; Dorcas, Michael E.

2014-01-01

Navigational ability is a critical component of an animal's spatial ecology and may influence the invasive potential of species. Burmese pythons (Python molurus bivittatus) are apex predators invasive to South Florida. We tracked the movements of 12 adult Burmese pythons in Everglades National Park, six of which were translocated 21–36 km from their capture locations. Translocated snakes oriented movement homeward relative to the capture location, and five of six snakes returned to within 5 km of the original capture location. Translocated snakes moved straighter and faster than control snakes and displayed movement path structure indicative of oriented movement. This study provides evidence that Burmese pythons have navigational map and compass senses and has implications for predictions of spatial spread and impacts as well as our understanding of reptile cognitive abilities. PMID:24647727

Homing of invasive Burmese pythons in South Florida: evidence for map and compass senses in snakes

USGS Publications Warehouse

Pittman, Shannon E.; Hart, Kristen M.; Cherkiss, Michael S.; Snow, Ray W.; Fujisaki, Ikuko; Mazzotti, Frank J.; Dorcas, Michael E.

2014-01-01

Navigational ability is a critical component of an animal's spatial ecology and may influence the invasive potential of species. Burmese pythons (Python molurus bivittatus) are apex predators invasive to South Florida. We tracked the movements of 12 adult Burmese pythons in Everglades National Park, six of which were translocated 21–36 km from their capture locations. Translocated snakes oriented movement homeward relative to the capture location, and five of six snakes returned to within 5 km of the original capture location. Translocated snakes moved straighter and faster than control snakes and displayed movement path structure indicative of oriented movement. This study provides evidence that Burmese pythons have navigational map and compass senses and has implications for predictions of spatial spread and impacts as well as our understanding of reptile cognitive abilities.

Two odometers in honeybees?

PubMed

Dacke, M; Srinivasan, M V

2008-10-01

Although several studies have examined how honeybees gauge and report the distance and direction of a food source to their nestmates, relatively little is known about how this information is combined to obtain a representation of the position of the food source. In this study we manipulate the amount of celestial compass information available to the bee during flight, and analyse the encoding of spatial information in the waggle dance as well as in the navigation of the foraging bee. We find that the waggle dance encodes information about the total distance flown to the food source, even when celestial compass cues are available only for a part of the journey. This stands in contrast to how a bee gauges distance flown when it navigates back to a food source that it already knows. When bees were trained to find a feeder placed at a fixed distance in a tunnel in which celestial cues were partially occluded and then tested in a tunnel that was fully open to the sky, they searched for the feeder at a distance that corresponds closely to the distance that was flown under the open sky during the training. Thus, when navigating back to a food source, information about distance travelled is disregarded when there is no concurrent input from the celestial compass. We suggest that bees may possess two different odometers - a 'community' odometer that is used to provide information to nestmates via the dance, and a 'personal' odometer that is used by an experienced individual to return to a previously visited source.

Fractionating dead reckoning: role of the compass, odometer, logbook, and home base establishment in spatial orientation

NASA Astrophysics Data System (ADS)

Wallace, Douglas G.; Martin, Megan M.; Winter, Shawn S.

2008-06-01

Rats use multiple sources of information to maintain spatial orientation. Although previous work has focused on rats’ use of environmental cues, a growing number of studies have demonstrated that rats also use self-movement cues to organize navigation. This review examines the extent that kinematic analysis of naturally occurring behavior has provided insight into processes that mediate dead-reckoning-based navigation. This work supports a role for separate systems in processing self-movement cues that converge on the hippocampus. The compass system is involved in deriving directional information from self-movement cues; whereas, the odometer system is involved in deriving distance information from self-movement cues. The hippocampus functions similar to a logbook in that outward path unique information from the compass and odometer is used to derive the direction and distance of a path to the point at which movement was initiated. Finally, home base establishment may function to reset this system after each excursion and anchor environmental cues to self-movement cues. The combination of natural behaviors and kinematic analysis has proven to be a robust paradigm to investigate the neural basis of spatial orientation.

Fractionating dead reckoning: role of the compass, odometer, logbook, and home base establishment in spatial orientation

PubMed Central

Martin, Megan M.; Winter, Shawn S.

2008-01-01

Rats use multiple sources of information to maintain spatial orientation. Although previous work has focused on rats' use of environmental cues, a growing number of studies have demonstrated that rats also use self-movement cues to organize navigation. This review examines the extent that kinematic analysis of naturally occurring behavior has provided insight into processes that mediate dead-reckoning-based navigation. This work supports a role for separate systems in processing self-movement cues that converge on the hippocampus. The compass system is involved in deriving directional information from self-movement cues; whereas, the odometer system is involved in deriving distance information from self-movement cues. The hippocampus functions similar to a logbook in that outward path unique information from the compass and odometer is used to derive the direction and distance of a path to the point at which movement was initiated. Finally, home base establishment may function to reset this system after each excursion and anchor environmental cues to self-movement cues. The combination of natural behaviors and kinematic analysis has proven to be a robust paradigm to investigate the neural basis of spatial orientation. PMID:18553065

Magnetoreception in eusocial insects: an update

PubMed Central

Wajnberg, Eliane; Acosta-Avalos, Daniel; Alves, Odivaldo Cambraia; de Oliveira, Jandira Ferreira; Srygley, Robert B.; Esquivel, Darci M. S.

2010-01-01

Behavioural experiments for magnetoreception in eusocial insects in the last decade are reviewed. Ants and bees use the geomagnetic field to orient and navigate in areas around their nests and along migratory paths. Bees show sensitivity to small changes in magnetic fields in conditioning experiments and when exiting the hive. For the first time, the magnetic properties of the nanoparticles found in eusocial insects, obtained by magnetic techniques and electron microscopy, are reviewed. Different magnetic oxide nanoparticles, ranging from superparamagnetic to multi-domain particles, were observed in all body parts, but greater relative concentrations in the abdomens and antennae of honeybees and ants have focused attention on these segments. Theoretical models for how these specific magnetosensory apparatuses function have been proposed. Neuron-rich ant antennae may be the most amenable to discovering a magnetosensor that will greatly assist research into higher order processing of magnetic information. The ferromagnetic hypothesis is believed to apply to eusocial insects, but interest in a light-sensitive mechanism is growing. The diversity of compass mechanisms in animals suggests that multiple compasses may function in insect orientation and navigation. The search for magnetic compasses will continue even after a magnetosensor is discovered in eusocial insects. PMID:20106876

Update on GPS Modernization Efforts

DTIC Science & Technology

2015-06-11

International Committee On Global Navigation Satellite Systems ( GNSS ) Department of Transportation • Federal Aviation Administration Satellite Block...90 for GNSS International Cooperation • 57 Authorized Allied Users - 25+ Years of Cooperation • GNSS - Europe - Galilee - China - COMPASS

How dim is dim? Precision of the celestial compass in moonlight and sunlight

PubMed Central

Dacke, M.; Byrne, M. J.; Baird, E.; Scholtz, C. H.; Warrant, E. J.

2011-01-01

Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim—and the polarization pattern too weak—to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision. PMID:21282173

Psychophysical study of the visual sun location in pictures of cloudy and twilight skies inspired by Viking navigation.

PubMed

Barta, András; Horváth, Gábor; Meyer-Rochow, Victor Benno

2005-06-01

In the late 1960s it was hypothesized that Vikings had been able to navigate the open seas, even when the sun was occluded by clouds or below the sea horizon, by using the angle of polarization of skylight. To detect the direction of skylight polarization, they were thought to have made use of birefringent crystals, called "sun-stones," and a large part of the scientific community still firmly believe that Vikings were capable of polarimetric navigation. However, there are some critics who treat the usefulness of skylight polarization for orientation under partly cloudy or twilight conditions with extreme skepticism. One of their counterarguments has been the assumption that solar positions or solar azimuth directions could be estimated quite accurately by the naked eye, even if the sun was behind clouds or below the sea horizon. Thus under partly cloudy or twilight conditions there might have been no serious need for a polarimetric method to determine the position of the sun. The aim of our study was to test quantitatively the validity of this qualitative counterargument. In our psychophysical laboratory experiments, test subjects were confronted with numerous 180 degrees field-of-view color photographs of partly cloudy skies with the sun occluded by clouds or of twilight skies with the sun below the horizon. The task of the subjects was to guess the position or the azimuth direction of the invisible sun with the naked eye. We calculated means and standard deviations of the estimated solar positions and azimuth angles to characterize the accuracy of the visual sun location. Our data do not support the common belief that the invisible sun can be located quite accurately from the celestial brightness and/or color patterns under cloudy or twilight conditions. Although our results underestimate the accuracy of visual sun location by experienced Viking navigators, the mentioned counterargument cannot be taken seriously as a valid criticism of the theory of the alleged polarimetric Viking navigation. Our results, however, do not bear on the polarimetric theory itself.

Sun-Compass Orientation in Mediterranean Fish Larvae.

PubMed

Faillettaz, Robin; Blandin, Agathe; Paris, Claire B; Koubbi, Philippe; Irisson, Jean-Olivier

2015-01-01

Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally.

Sun-Compass Orientation in Mediterranean Fish Larvae

PubMed Central

Faillettaz, Robin; Blandin, Agathe; Paris, Claire B.; Koubbi, Philippe; Irisson, Jean-Olivier

2015-01-01

Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally. PMID:26308915

Orienteering: A Thinging Man's Sport or It's Not Nice to Fool Mother Nature

ERIC Educational Resources Information Center

August, Irwin

1974-01-01

Orienteering is land navigation through unknown countryside with map and compass. This article describes an orienteering program in the Action Education Curriculum, State University of New York, College at Purchase. (KM)

Infrasound and the avian navigational map

USGS Publications Warehouse

Hagstrum, J.T.

2001-01-01

Birds can accurately navigate over hundreds to thousands of kilometres, and use celestial and magnetic compass senses to orient their flight. How birds determine their location in order to select the correct homeward bearing (map sense) remains controversial, and has been attributed to their olfactory or magnetic senses. Pigeons can hear infrasound down to 0??05 Hz, and an acoustic avian map is proposed consisting of infrasonic cues radiated from steep-sided topographic features. The source of these infrasonic signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting the infrasonic map cues can explain perplexing experimental results from pigeon releases. Moreover, four recent disrupted pigeon races in Europe and the north-eastern USA intersected infrasonic shock waves from the Concorde supersonic transport. Having an acoustic map might also allow clock-shifted birds to test their homeward progress and select between their magnetic and solar compasses.

A New View on an Old Debate: Type of Cue-Conflict Manipulation and Availability of Stars Can Explain the Discrepancies between Cue-Calibration Experiments with Migratory Songbirds.

PubMed

Sjöberg, Sissel; Muheim, Rachel

2016-01-01

Migratory birds use multiple compass systems for orientation, including a magnetic, star and sun/polarized light compass. To keep these compasses in register, birds have to regularly update them with respect to a common reference. However, cue-conflict studies have revealed contradictory results on the compass hierarchy, favoring either celestial or magnetic compass cues as the primary calibration reference. Both the geomagnetic field and polarized light cues present at sunrise and sunset have been shown to play a role in compass cue integration, and evidence suggests that polarized light cues at sunrise and sunset may provide the primary calibration reference for the other compass systems. We tested whether migratory garden warblers recalibrated their compasses when they were exposed to the natural celestial cues at sunset in a shifted magnetic field, which are conditions that have been shown to be necessary for the use of a compass reference based on polarized light cues. We released the birds on the same evening under a starry sky and followed them by radio tracking. We found no evidence of compass recalibration, even though the birds had a full view of polarized light cues near the horizon at sunset during the cue-conflict exposure. Based on a meta-analysis of the available literature, we propose an extended unifying theory on compass cue hierarchy used by migratory birds to calibrate the different compasses. According to this scheme, birds recalibrate their magnetic compass by sunrise/sunset polarized light cues, provided they have access to the vertically aligned band of maximum polarization near the horizon and a view of landmarks. Once the stars appear in the sky, the birds then recalibrate the star compass with respect of the recalibrated magnetic compass. If sunrise and sunset information can be viewed from the same location, the birds average the information to get a true geographic reference. If polarized light information is not available near the horizon at sunrise or sunset, the birds temporarily transfer the previously calibrated magnetic compass information to the available celestial compasses. We conclude that the type of cue-conflict manipulation and the availability of stars can explain the discrepancies between studies.

A New View on an Old Debate: Type of Cue-Conflict Manipulation and Availability of Stars Can Explain the Discrepancies between Cue-Calibration Experiments with Migratory Songbirds

PubMed Central

Sjöberg, Sissel; Muheim, Rachel

2016-01-01

Migratory birds use multiple compass systems for orientation, including a magnetic, star and sun/polarized light compass. To keep these compasses in register, birds have to regularly update them with respect to a common reference. However, cue-conflict studies have revealed contradictory results on the compass hierarchy, favoring either celestial or magnetic compass cues as the primary calibration reference. Both the geomagnetic field and polarized light cues present at sunrise and sunset have been shown to play a role in compass cue integration, and evidence suggests that polarized light cues at sunrise and sunset may provide the primary calibration reference for the other compass systems. We tested whether migratory garden warblers recalibrated their compasses when they were exposed to the natural celestial cues at sunset in a shifted magnetic field, which are conditions that have been shown to be necessary for the use of a compass reference based on polarized light cues. We released the birds on the same evening under a starry sky and followed them by radio tracking. We found no evidence of compass recalibration, even though the birds had a full view of polarized light cues near the horizon at sunset during the cue-conflict exposure. Based on a meta-analysis of the available literature, we propose an extended unifying theory on compass cue hierarchy used by migratory birds to calibrate the different compasses. According to this scheme, birds recalibrate their magnetic compass by sunrise/sunset polarized light cues, provided they have access to the vertically aligned band of maximum polarization near the horizon and a view of landmarks. Once the stars appear in the sky, the birds then recalibrate the star compass with respect of the recalibrated magnetic compass. If sunrise and sunset information can be viewed from the same location, the birds average the information to get a true geographic reference. If polarized light information is not available near the horizon at sunrise or sunset, the birds temporarily transfer the previously calibrated magnetic compass information to the available celestial compasses. We conclude that the type of cue-conflict manipulation and the availability of stars can explain the discrepancies between studies. PMID:26941631

Psychophysical study of the visual sun location in pictures of cloudy and twilight skies inspired by Viking navigation

NASA Astrophysics Data System (ADS)

Barta, András; Horváth, Gábor; Benno Meyer-Rochow, Victor

2005-06-01

In the late 1960s it was hypothesized that Vikings had been able to navigate the open seas, even when the sun was occluded by clouds or below the sea horizon, by using the angle of polarization of skylight. To detect the direction of skylight polarization, they were thought to have made use of birefringent crystals, called "sunstones," and a large part of the scientific community still firmly believe that Vikings were capable of polarimetric navigation. However, there are some critics who treat the usefulness of skylight polarization for orientation under partly cloudy or twilight conditions with extreme skepticism. One of their counterarguments has been the assumption that solar positions or solar azimuth directions could be estimated quite accurately by the naked eye, even if the sun was behind clouds or below the sea horizon. Thus under partly cloudy or twilight conditions there might have been no serious need for a polarimetric method to determine the position of the sun. The aim of our study was to test quantitatively the validity of this qualitative counterargument. In our psychophysical laboratory experiments, test subjects were confronted with numerous 180° field-of-view color photographs of partly cloudy skies with the sun occluded by clouds or of twilight skies with the sun below the horizon. The task of the subjects was to guess the position or the azimuth direction of the invisible sun with the naked eye. We calculated means and standard deviations of the estimated solar positions and azimuth angles to characterize the accuracy of the visual sun location. Our data do not support the common belief that the invisible sun can be located quite accurately from the celestial brightness and/or color patterns under cloudy or twilight conditions. Although our results underestimate the accuracy of visual sun location by experienced Viking navigators, the mentioned counterargument cannot be taken seriously as a valid criticism of the theory of the alleged polarimetric Viking navigation. Our results, however, do not bear on the polarimetric theory itself.

Migrating songbirds recalibrate their magnetic compass daily from twilight cues.

PubMed

Cochran, William W; Mouritsen, Henrik; Wikelski, Martin

2004-04-16

Night migratory songbirds can use stars, sun, geomagnetic field, and polarized light for orientation when tested in captivity. We studied the interaction of magnetic, stellar, and twilight orientation cues in free-flying songbirds. We exposed Catharus thrushes to eastward-turned magnetic fields during the twilight period before takeoff and then followed them for up to 1100 kilometers. Instead of heading north, experimental birds flew westward. On subsequent nights, the same individuals migrated northward again. We suggest that birds orient with a magnetic compass calibrated daily from twilight cues. This could explain how birds cross the magnetic equator and deal with declination.

A Neurocomputational Model of Goal-Directed Navigation in Insect-Inspired Artificial Agents

PubMed Central

Goldschmidt, Dennis; Manoonpong, Poramate; Dasgupta, Sakyasingha

2017-01-01

Despite their small size, insect brains are able to produce robust and efficient navigation in complex environments. Specifically in social insects, such as ants and bees, these navigational capabilities are guided by orientation directing vectors generated by a process called path integration. During this process, they integrate compass and odometric cues to estimate their current location as a vector, called the home vector for guiding them back home on a straight path. They further acquire and retrieve path integration-based vector memories globally to the nest or based on visual landmarks. Although existing computational models reproduced similar behaviors, a neurocomputational model of vector navigation including the acquisition of vector representations has not been described before. Here we present a model of neural mechanisms in a modular closed-loop control—enabling vector navigation in artificial agents. The model consists of a path integration mechanism, reward-modulated global learning, random search, and action selection. The path integration mechanism integrates compass and odometric cues to compute a vectorial representation of the agent's current location as neural activity patterns in circular arrays. A reward-modulated learning rule enables the acquisition of vector memories by associating the local food reward with the path integration state. A motor output is computed based on the combination of vector memories and random exploration. In simulation, we show that the neural mechanisms enable robust homing and localization, even in the presence of external sensory noise. The proposed learning rules lead to goal-directed navigation and route formation performed under realistic conditions. Consequently, we provide a novel approach for vector learning and navigation in a simulated, situated agent linking behavioral observations to their possible underlying neural substrates. PMID:28446872

Development of a GPS/INS/MAG navigation system and waypoint navigator for a VTOL UAV

NASA Astrophysics Data System (ADS)

Meister, Oliver; Mönikes, Ralf; Wendel, Jan; Frietsch, Natalie; Schlaile, Christian; Trommer, Gert F.

2007-04-01

Unmanned aerial vehicles (UAV) can be used for versatile surveillance and reconnaissance missions. If a UAV is capable of flying automatically on a predefined path the range of possible applications is widened significantly. This paper addresses the development of the integrated GPS/INS/MAG navigation system and a waypoint navigator for a small vertical take-off and landing (VTOL) unmanned four-rotor helicopter with a take-off weight below 1 kg. The core of the navigation system consists of low cost inertial sensors which are continuously aided with GPS, magnetometer compass, and a barometric height information. Due to the fact, that the yaw angle becomes unobservable during hovering flight, the integration with a magnetic compass is mandatory. This integration must be robust with respect to errors caused by the terrestrial magnetic field deviation and interferences from surrounding electronic devices as well as ferrite metals. The described integration concept with a Kalman filter overcomes the problem that erroneous magnetic measurements yield to an attitude error in the roll and pitch axis. The algorithm provides long-term stable navigation information even during GPS outages which is mandatory for the flight control of the UAV. In the second part of the paper the guidance algorithms are discussed in detail. These algorithms allow the UAV to operate in a semi-autonomous mode position hold as well an complete autonomous waypoint mode. In the position hold mode the helicopter maintains its position regardless of wind disturbances which ease the pilot job during hold-and-stare missions. The autonomous waypoint navigator enable the flight outside the range of vision and beyond the range of the radio link. Flight test results of the implemented modes of operation are shown.

A Neurocomputational Model of Goal-Directed Navigation in Insect-Inspired Artificial Agents.

PubMed

Goldschmidt, Dennis; Manoonpong, Poramate; Dasgupta, Sakyasingha

2017-01-01

Despite their small size, insect brains are able to produce robust and efficient navigation in complex environments. Specifically in social insects, such as ants and bees, these navigational capabilities are guided by orientation directing vectors generated by a process called path integration. During this process, they integrate compass and odometric cues to estimate their current location as a vector, called the home vector for guiding them back home on a straight path. They further acquire and retrieve path integration-based vector memories globally to the nest or based on visual landmarks. Although existing computational models reproduced similar behaviors, a neurocomputational model of vector navigation including the acquisition of vector representations has not been described before. Here we present a model of neural mechanisms in a modular closed-loop control-enabling vector navigation in artificial agents. The model consists of a path integration mechanism, reward-modulated global learning, random search, and action selection. The path integration mechanism integrates compass and odometric cues to compute a vectorial representation of the agent's current location as neural activity patterns in circular arrays. A reward-modulated learning rule enables the acquisition of vector memories by associating the local food reward with the path integration state. A motor output is computed based on the combination of vector memories and random exploration. In simulation, we show that the neural mechanisms enable robust homing and localization, even in the presence of external sensory noise. The proposed learning rules lead to goal-directed navigation and route formation performed under realistic conditions. Consequently, we provide a novel approach for vector learning and navigation in a simulated, situated agent linking behavioral observations to their possible underlying neural substrates.

Quantum imaging for underwater arctic navigation

NASA Astrophysics Data System (ADS)

Lanzagorta, Marco

2017-05-01

The precise navigation of underwater vehicles is a difficult task due to the challenges imposed by the variable oceanic environment. It is particularly difficult if the underwater vehicle is trying to navigate under the Arctic ice shelf. Indeed, in this scenario traditional navigation devices such as GPS, compasses and gyrocompasses are unavailable or unreliable. In addition, the shape and thickness of the ice shelf is variable throughout the year. Current Arctic underwater navigation systems include sonar arrays to detect the proximity to the ice. However, these systems are undesirable in a wartime environment, as the sound gives away the position of the underwater vehicle. In this paper we briefly describe the theoretical design of a quantum imaging system that could allow the safe and stealthy navigation of underwater Arctic vehicles.

Not all songbirds calibrate their magnetic compass from twilight cues: a telemetry study.

PubMed

Chernetsov, Nikita; Kishkinev, Dmitry; Kosarev, Vladislav; Bolshakov, Casimir V

2011-08-01

Migratory birds are able to use the sun and associated polarised light patterns, stellar cues and the geomagnetic field for orientation. No general agreement has been reached regarding the hierarchy of orientation cues. Recent data from naturally migrating North American Catharus thrushes suggests that they calibrate geomagnetic information daily from twilight cues. Similar results have been shown in caged birds in a few studies but not confirmed in others. We report that free-flying European migrants, song thrushes Turdus philomelos, released after pre-exposure to a horizontally rotated magnetic field, do not recalibrate their magnetic compass from solar cues, but rather show a simple domination of either the magnetic or the stellar compass. We suggest that different songbird species possess different hierarchies of orientation cues, depending on the geographic and ecological challenges met by the migrants.

Never Too Young to Orienteer.

ERIC Educational Resources Information Center

Lavine, Carolyn

1992-01-01

Describes orienteering courses for children, including courses that introduce young children to the idea of navigating in the outdoors and courses that teach map and compass skills and problem-solving techniques to older children. Lists sources of information and references. (SV)

Migrating songbirds tested in computer-controlled Emlen funnels use stellar cues for a time-independent compass.

PubMed

Mouritsen, H; Larsen, O N

2001-11-01

This paper investigates how young pied flycatchers, Ficedula hypoleuca, and blackcaps, Sylvia atricapilla, interpret and use celestial cues. In order to record these data, we developed a computer-controlled version of the Emlen funnel, which enabled us to make detailed temporal analyses. First, we showed that the birds use a star compass. Then, we tested the birds under a stationary planetarium sky, which simulated the star pattern of the local sky at 02:35 h for 11 consecutive hours of the night, and compared the birds' directional choices as a function of time with the predictions from five alternative stellar orientation hypotheses. The results supported the hypothesis suggesting that birds use a time-independent star compass based on learned geometrical star configurations to pinpoint the rotational point of the starry sky (north). In contrast, neither hypotheses suggesting that birds use the stars for establishing their global position and then perform true star navigation nor those suggesting the use of a time-compensated star compass were supported.

Coupled solar-magnetic orientation during leatherback turtle (Dermochelys coriacea), great white shark (Carcharodon carcharias), arctic tern (Sterna paradisaea), and humpback whale (Megaptera novaeangliae) long-distance migration

NASA Astrophysics Data System (ADS)

Horton, T. W.; Holdaway, R. N.; Zerbini, A.; Andriolo, A.; Clapham, P. J.

2010-12-01

Determining how animals perform long-distance animal migration remains one of the most enduring and fundamental mysteries of behavioural ecology. It is widely accepted that navigation relative to a reference datum is a fundamental requirement of long-distance return migration between seasonal habitats, and significant experimental research has documented a variety of viable orientation and navigation cues. However, relatively few investigations have attempted to reconcile experimentally determined orientation and navigation capacities of animals with empirical remotely sensed animal track data, leaving most theories of navigation and orientation untested. Here we show, using basic hypothesis testing, that leatherback turtle (Dermochelys coriacea), great white shark (Carcharodon carcharias), arctic tern (Sterna paradisaea), and humpback whale (Megaptera novaeangliae) migration paths are non-randomly distributed in magnetic coordinate space, with local peaks in magnetic coordinate distributions equal to fractional multiples of the angular obliquity of Earth’s axis of rotation. Time series analysis of humpback whale migratory behaviours, including migration initiation, changes in course, and migratory stop-overs, further demonstrate coupling of magnetic and celestial orientation cues during long-distance migration. These unexpected and highly novel results indicate that diverse taxa integrate magnetic and celestial orientation cues during long-distance migration. These results are compatible with a 'map and compass' orientation and navigation system. Humpback whale migration track geometries further indicate a map and compass orientation system is used. Several humpback whale tracks include highly directional segments (Mercator latitude vs. longitude r2>0.99) exceeding 2000 km in length, despite exposure to variable strength (c. 0-1 km/hr) surface cross-currents. Humpback whales appear to be able to compensate for surface current drift. The remarkable directional precision of these humpback whale track segments is far better than the ±25°-40° precision of the avian magnetic compass. The positional and directional orientation data presented suggests signal transduction provides spatial information to migrating animals with better than 1° precision.

Interdisciplinary Navigation Unit for Mathematics and Earth Science Using Geospatial Technology

NASA Astrophysics Data System (ADS)

Smaglik, S. M.; Harris, V.

2006-12-01

Central Wyoming College (CWC) is located northeast of the Wind River Mountains. Although many people find recreation in the wilderness and remote areas surrounding the area, people still lose their lives because they become lost or disoriented. Creating an interdisciplinary field-based curriculum unit within mathematics (MATH 1000) and earth science (GEOL 1070) courses for non-science and education majors, provides students an opportunity to develop critical thinking skills and quantitative literacy. It also provides some necessary skills for survival and an understanding of landscape formation and wilderness navigation using geoscience. A brief history of navigation, including the importance of finding latitude and longitude, and the fairly recent implementation of the Global Positioning System, precedes activities in which students learn to use a basic compass. In addition to learning how to adjust for magnetic declination they read topographic maps, specifically USGS quadrangles, and learn how to use the scale in the legend to verify calculations using the Pythagorean Theorem. Students learn how to estimate distance and time required for traveling a pre- determined distance while using dimensional analysis to convert from the English system to metric. They learn how to read and measure latitude and longitude, as well as universal transverse Mercator projection measurements (UTM's), to find their position. The basic mathematical skills are assessed through hands-on activities such as finding their location on a map using a compass, a GPS unit, and Google Earth, and using a combination of maps, compasses, and GPS units to navigate through a course. Our goal is to provide life-saving information to students while incorporating necessary core curriculum from both mathematics and earth science classes. We work to create field-based activities, as well as assessments, to insure that students who complete the course are prepared to safely enjoy the outdoors and are prepared for future courses requiring mathematical problem-solving and/or lab science as a prerequisite.

Solar-based navigation for robotic explorers

NASA Astrophysics Data System (ADS)

Shillcutt, Kimberly Jo

2000-12-01

This thesis introduces the application of solar position and shadowing information to robotic exploration. Power is a critical resource for robots with remote, long-term missions, so this research focuses on the power generation capabilities of robotic explorers during navigational tasks, in addition to power consumption. Solar power is primarily considered, with the possibility of wind power also contemplated. Information about the environment, including the solar ephemeris, terrain features, time of day, and surface location, is incorporated into a planning structure, allowing robots to accurately predict shadowing and thus potential costs and gains during navigational tasks. By evaluating its potential to generate and expend power, a robot can extend its lifetime and accomplishments. The primary tasks studied are coverage patterns, with a variety of plans developed for this research. The use of sun, terrain and temporal information also enables new capabilities of identifying and following sun-synchronous and sun-seeking paths. Digital elevation maps are combined with an ephemeris algorithm to calculate the altitude and azimuth of the sun from surface locations, and to identify and map shadows. Solar navigation path simulators use this information to perform searches through two-dimensional space, while considering temporal changes. Step by step simulations of coverage patterns also incorporate time in addition to location. Evaluations of solar and wind power generation, power consumption, area coverage, area overlap, and time are generated for sets of coverage patterns, with on-board environmental information linked to the simulations. This research is implemented on the Nomad robot for the Robotic Antarctic Meteorite Search. Simulators have been developed for coverage pattern tests, as well as for sun-synchronous and sun-seeking path searches. Results of field work and simulations are reported and analyzed, with demonstrated improvements in efficiency, productivity and lifetime of robotic explorers, along with new solar navigation abilities.

47 CFR 80.5 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... located on a ship's navigational bridge or main control station operating on a specified frequency which... Union Radiocommunication (ITU-R) Sector, used to establish contact with a station or group of stations... (ITU), Place des Nations, CH-1211 Geneva 20, Switzerland. Direction finder (radio compass). Apparatus...

47 CFR 80.5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... located on a ship's navigational bridge or main control station operating on a specified frequency which... Union Radiocommunication (ITU-R) Sector, used to establish contact with a station or group of stations... (ITU), Place des Nations, CH-1211 Geneva 20, Switzerland. Direction finder (radio compass). Apparatus...

Smartphone-based solutions to monitor and reduce fuel consumption and CO2 footprint : final report.

DOT National Transportation Integrated Search

2016-06-01

Smartphones equipped with GPS and several low-energy sensors (e.g., gyroscope, compass, and accelerometer) can provide a medium to collect probe data. As smartphone users navigate the transportation networks, their travel modes and trajectories can b...

14 CFR 61.125 - Aeronautical knowledge.

Code of Federal Regulations, 2013 CFR

2013-01-01

... magnetic compass for pilotage and dead reckoning; (10) Use of air navigation facilities; (11) Aeronautical... aeronautical knowledge areas of paragraph (b) of this section that apply to the aircraft category and class... operation of aircraft; (6) Weight and balance computations; (7) Use of performance charts; (8) Significance...

The Roles of Innate Information, Learning Rules and Plasticity in Migratory Bird Orientation

NASA Astrophysics Data System (ADS)

Able, Kenneth P.; Able, Mary A.

This paper and the following three papers were presented at the RIN97 Conference held in Oxford under the auspices of the Animal Navigation Special Interest Group, April 1997. The full proceedings, under the title Orientation and Navigation - Birds, Humans and Other Animals, can be obtained from the Director (£30 to Members, £50 to non-Members).Studies of the compass mechanisms involved in the migratory orientation of birds have revealed a complex web of interactions, both during the development of orientation behaviour in young birds and in mature individuals exhibiting migratory activity. In young birds, the acquisition of compass orientation capabilities involves the interplay of apparently genetically programmed information with a suite of innate learning rules. The latter canalise the ways in which experience with relevant orientation information from the environment impinges on development. There are many general similarities with the development of singing behaviour in songbirds, although that system is more thoroughly understood, especially at the neuronal level.Here we shall attempt to synthesise what is known about the development of compass mechanisms in a framework of innate information and learning rules. The way in which orientation behaviour develops leaves open the possibility for plasticity that enables birds to compensate for variability in the environmental cues that form the basis of their compasses. For at least some components of the system, behavioural plasticity remains into adulthood, allowing the bird on migration to respond in apparently adaptive ways to spatial and temporal variability in orientation information that it may encounter while enroute. We have studied these questions in the Savannah sparrow (Passerculus sandwichensis), a medium-distance North American emberizine nocturnal migrant. We will focus on that species, relating the results of our work to relevant studies on others.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakaguchi, Yuji, E-mail: nkgc2003@yahoo.co.jp; Ono, Takeshi; Onitsuka, Ryota

COMPASS system (IBA Dosimetry, Schwarzenbruck, Germany) and ArcCHECK with 3DVH software (Sun Nuclear Corp., Melbourne, FL) are commercial quasi-3-dimensional (3D) dosimetry arrays. Cross-validation to compare them under the same conditions, such as a treatment plan, allows for clear evaluation of such measurement devices. In this study, we evaluated the accuracy of reconstructed dose distributions from the COMPASS system and ArcCHECK with 3DVH software using Monte Carlo simulation (MC) for multi-leaf collimator (MLC) test patterns and clinical VMAT plans. In a phantom study, ArcCHECK 3DVH showed clear differences from COMPASS, measurement and MC due to the detector resolution and the dosemore » reconstruction method. Especially, ArcCHECK 3DVH showed 7% difference from MC for the heterogeneous phantom. ArcCHECK 3DVH only corrects the 3D dose distribution of treatment planning system (TPS) using ArcCHECK measurement, and therefore the accuracy of ArcCHECK 3DVH depends on TPS. In contrast, COMPASS showed good agreement with MC for all cases. However, the COMPASS system requires many complicated installation procedures such as beam modeling, and appropriate commissioning is needed. In terms of clinical cases, there were no large differences for each QA device. The accuracy of the compass and ArcCHECK 3DVH systems for phantoms and clinical cases was compared. Both systems have advantages and disadvantages for clinical use, and consideration of the operating environment is important. The QA system selection is depending on the purpose and workflow in each hospital.« less

The Neural Basis of Long-Distance Navigation in Birds.

PubMed

Mouritsen, Henrik; Heyers, Dominik; Güntürkün, Onur

2016-01-01

Migratory birds can navigate over tens of thousands of kilometers with an accuracy unobtainable for human navigators. To do so, they use their brains. In this review, we address how birds sense navigation- and orientation-relevant cues and where in their brains each individual cue is processed. When little is currently known, we make educated predictions as to which brain regions could be involved. We ask where and how multisensory navigational information is integrated and suggest that the hippocampus could interact with structures that represent maps and compass information to compute and constantly control navigational goals and directions. We also suggest that the caudolateral nidopallium could be involved in weighing conflicting pieces of information against each other, making decisions, and helping the animal respond to unexpected situations. Considering the gaps in current knowledge, some of our suggestions may be wrong. However, our main aim is to stimulate further research in this fascinating field.

Polarized skylight does not calibrate the compass system of a migratory bat

PubMed Central

Lindecke, Oliver; Voigt, Christian C.; Pētersons, Gunārs; Holland, Richard A.

2015-01-01

In a recent study, Greif et al. (Greif et al. Nat Commun 5, 4488. (doi:10.1038/ncomms5488)) demonstrated a functional role of polarized light for a bat species confronted with a homing task. These non-migratory bats appeared to calibrate their magnetic compass by using polarized skylight at dusk, yet it is unknown if migratory bats also use these cues for calibration. During autumn migration, we equipped Nathusius' bats, Pipistrellus nathusii, with radio transmitters and tested if experimental animals exposed during dusk to a 90° rotated band of polarized light would head in a different direction compared with control animals. After release, bats of both groups continued their journey in the same direction. This observation argues against the use of a polarization-calibrated magnetic compass by this migratory bat and questions that the ability of using polarized light for navigation is a consistent feature in bats. This finding matches with observations in some passerine birds that used polarized light for calibration of their magnetic compass before but not during migration. PMID:26382077

Polarized skylight does not calibrate the compass system of a migratory bat.

PubMed

Lindecke, Oliver; Voigt, Christian C; Pētersons, Gunārs; Holland, Richard A

2015-09-01

In a recent study, Greif et al. (Greif et al. Nat Commun 5, 4488. (doi:10.1038/ncomms5488)) demonstrated a functional role of polarized light for a bat species confronted with a homing task. These non-migratory bats appeared to calibrate their magnetic compass by using polarized skylight at dusk, yet it is unknown if migratory bats also use these cues for calibration. During autumn migration, we equipped Nathusius' bats, Pipistrellus nathusii, with radio transmitters and tested if experimental animals exposed during dusk to a 90° rotated band of polarized light would head in a different direction compared with control animals. After release, bats of both groups continued their journey in the same direction. This observation argues against the use of a polarization-calibrated magnetic compass by this migratory bat and questions that the ability of using polarized light for navigation is a consistent feature in bats. This finding matches with observations in some passerine birds that used polarized light for calibration of their magnetic compass before but not during migration. © 2015 The Author(s).

Flow-Centric, Back-in-Time Debugging

NASA Astrophysics Data System (ADS)

Lienhard, Adrian; Fierz, Julien; Nierstrasz, Oscar

Conventional debugging tools present developers with means to explore the run-time context in which an error has occurred. In many cases this is enough to help the developer discover the faulty source code and correct it. However, rather often errors occur due to code that has executed in the past, leaving certain objects in an inconsistent state. The actual run-time error only occurs when these inconsistent objects are used later in the program. So-called back-in-time debuggers help developers step back through earlier states of the program and explore execution contexts not available to conventional debuggers. Nevertheless, even Back-in-Time Debuggers do not help answer the question, “Where did this object come from?” The Object-Flow Virtual Machine, which we have proposed in previous work, tracks the flow of objects to answer precisely such questions, but this VM does not provide dedicated debugging support to explore faulty programs. In this paper we present a novel debugger, called Compass, to navigate between conventional run-time stack-oriented control flow views and object flows. Compass enables a developer to effectively navigate from an object contributing to an error back-in-time through all the code that has touched the object. We present the design and implementation of Compass, and we demonstrate how flow-centric, back-in-time debugging can be used to effectively locate the source of hard-to-find bugs.

14 CFR Appendix A to Part 141 - Recreational Pilot Certification Course

Code of Federal Regulations, 2013 CFR

2013-01-01

... navigation using pilotage with the aid of a magnetic compass; (e) Recognition of critical weather situations... the aircraft category and class for which the course applies: (a) Applicable Federal Aviation... reports and forecasts; (f) Safe and efficient operation of aircraft, including collision avoidance, and...

Sun compensation by bees.

PubMed

Gould, J L

1980-02-01

In both their navigation and dance communication, bees are able to compensate for the sun's movement. When foragers are prevented from seeing the sun for 2 hours, they compensate by extrapolation, using the sun's rate of movement when last observed. These and other data suggest a time-averaging processing strategy in honey bee orientation.

Navigating through translational research: a social marketing compass.

PubMed

Wharf Higgins, Joan

2011-01-01

When prominent health issues are chronic, rooted in complex behaviors, and influenced by cognitive, behavioral, social, cultural, economical, and environmental variables, layered and coordinated interventions are needed. Finding solutions that are valid, reliable, and transferable represents a daunting task for researchers. We know that converting science into action is critical for advancing health, but we have failed to appropriately disseminate evidenced-informed research to practitioners. The purpose of this article is to suggest that a social marketing framework can be the compass down this road less traveled in academic research. An experience developing an evaluation toolkit is described as an example of applying social marketing strategies to knowledge translation.

Not Half; Not Some.

ERIC Educational Resources Information Center

Glasser, Perry

1997-01-01

Teachers must learn to navigate an increasingly polluted ocean of educational hype. During his second year of teaching English, the author was handed a compass. Discussing her underachieving daughter, a black mother advised this teacher to drop the "relevant" units on gangs and give her daughter everything he knew (about Shakespeare and…

Celestial Navigation, with a Moral Compass.

ERIC Educational Resources Information Center

Donovan, Aine

1999-01-01

Kantian reasoning fails to address the needs of a mixed-gender peace-keeping force. A philosophy professor at the U.S. Naval Academy proposes a normative-ethics instructional model based on acceptance of duty and obedience (justice) and cultivation of reflective concern for individual choice and responsibility (caring). (24 references) (MLH)

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2013 CFR

2013-01-01

... knowledge areas of paragraph (b) of this section that apply to the aircraft category and class rating sought... “Aeronautical Information Manual” and FAA advisory circulars; (4) Use of aeronautical charts for VFR navigation using pilotage with the aid of a magnetic compass; (5) Recognition of critical weather situations from...

Orienteering: A Swedish Way of Life.

ERIC Educational Resources Information Center

Oliver, Rick

1984-01-01

Orienteering involves navigating over an unfamiliar route with a map and a compass and locating control markers as quickly as possible. Originating in Sweden, orienting began primarily as a military event and has grown into "a sport for all." Suggested activities in orienteering to conduct in school conclude the article. (ERB)

Daytime Celestial Navigation for the Novice

NASA Astrophysics Data System (ADS)

Sadler, Philip M.; Night, Christopher

2010-03-01

What kinds of astronomical lab activities can high school and college astronomy students carry out easily in daytime? The most impressive is the determination of latitude and longitude from observations of the Sun. The ``shooting of a noon sight'' and its ``reduction to a position'' grew to become a daily practice at the start of the 19th century1 following the perfection of the marine chronometer by John Harrison and its mass production.2 This technique is still practiced by navigators in this age of GPS. Indeed, the U.S. Coast Guard exams for ocean-going licenses include celestial navigation.3 These techniques continue to be used by the military and by private sailors as a backup to all-too-fallible and jammable electronic navigation systems. A sextant, a nautical almanac,4 special sight reduction tables,5 and involved calculations are needed to determine position to the nearest mile using the Sun, Moon, stars, or planets. Yet, finding latitude and longitude to better than 30 miles from measurements of the Sun's altitude is easily within the capability of those taking astronomy or physics for the first time by applying certain basic principles. Moreover, it shows a practical application of astronomy in use the world over. The streamlined method described here takes advantage of the similar level of accuracy of its three components: 1.Observations using a homemade quadrant6 (instead of a sextant), 2. Student-made graphs of the altitude of the Sun over a day7 (replacing lengthy calculation using sight reduction tables), and 3. An averaged 20-year analemma used to find the Sun's navigational coordinates8,9 (rather than the 300+ page Nautical Almanac updated yearly).

Conflicting evidence about long-distance animal navigation.

PubMed

Alerstam, Thomas

2006-08-11

Because of conflicting evidence about several fundamental issues, long-distance animal navigation has yet to be satisfactorily explained. Among the unsolved problems are the nature of genetic spatial control of migration and the relationships between celestial and magnetic compass mechanisms and between different map-related cues in orientation and homing, respectively. In addition, navigation is expected to differ between animal groups depending on sensory capabilities and ecological conditions. Evaluations based on modern long-term tracking techniques of the geometry of migration routes and individual migration history, combined with behavioral experiments and exploration of the sensory and genetic mechanisms, will be crucial for understanding the spatial principles that guide animals on their global journeys.

Interaction of compass sensing and object-motion detection in the locust central complex.

PubMed

Bockhorst, Tobias; Homberg, Uwe

2017-07-01

Goal-directed behavior is often complicated by unpredictable events, such as the appearance of a predator during directed locomotion. This situation requires adaptive responses like evasive maneuvers followed by subsequent reorientation and course correction. Here we study the possible neural underpinnings of such a situation in an insect, the desert locust. As in other insects, its sense of spatial orientation strongly relies on the central complex, a group of midline brain neuropils. The central complex houses sky compass cells that signal the polarization plane of skylight and thus indicate the animal's steering direction relative to the sun. Most of these cells additionally respond to small moving objects that drive fast sensory-motor circuits for escape. Here we investigate how the presentation of a moving object influences activity of the neurons during compass signaling. Cells responded in one of two ways: in some neurons, responses to the moving object were simply added to the compass response that had adapted during continuous stimulation by stationary polarized light. By contrast, other neurons disadapted, i.e., regained their full compass response to polarized light, when a moving object was presented. We propose that the latter case could help to prepare for reorientation of the animal after escape. A neuronal network based on central-complex architecture can explain both responses by slight changes in the dynamics and amplitudes of adaptation to polarized light in CL columnar input neurons of the system. NEW & NOTEWORTHY Neurons of the central complex in several insects signal compass directions through sensitivity to the sky polarization pattern. In locusts, these neurons also respond to moving objects. We show here that during polarized-light presentation, responses to moving objects override their compass signaling or restore adapted inhibitory as well as excitatory compass responses. A network model is presented to explain the variations of these responses that likely serve to redirect flight or walking following evasive maneuvers. Copyright © 2017 the American Physiological Society.

Integration of celestial compass cues in the central complex of the locust brain.

PubMed

Pegel, Uta; Pfeiffer, Keram; Homberg, Uwe

2018-01-29

Many insects rely on celestial compass cues such as the polarization pattern of the sky for spatial orientation. In the desert locust, the central complex (CX) houses multiple sets of neurons, sensitive to the oscillation plane of polarized light and thus probably acts as an internal polarization compass. We investigated whether other sky compass cues like direct sunlight or the chromatic gradient of the sky might contribute to this compass. We recorded from polarization-sensitive CX neurons while an unpolarized green or ultraviolet light spot was moved around the head of the animal. All types of neuron that were sensitive to the plane of polarization ( E -vector) above the animal also responded to the unpolarized light spots in an azimuth-dependent way. The tuning to the unpolarized light spots was independent of wavelength, suggesting that the neurons encode solar azimuth based on direct sunlight and not on the sky chromatic gradient. Two cell types represented the natural 90 deg relationship between solar azimuth and zenithal E -vector orientation, providing evidence to suggest that solar azimuth information supports the internal polarization compass. Most neurons showed advances in their tuning to the E -vector and the unpolarized light spots dependent on rotation direction, consistent with anticipatory signaling. The amplitude of responses and its variability were dependent on the level of background firing, possibly indicating different internal states. The integration of polarization and solar azimuth information strongly suggests that besides the polarization pattern of the sky, direct sunlight might be an important cue for sky compass navigation in the locust. © 2018. Published by The Company of Biologists Ltd.

The case for values as a basis for organizational culture.

PubMed

Brinkley, Ruth W

2013-01-01

At a time when almost every aspect of healthcare is rapidly and dramatically changing, it is important for healthcare leaders to maintain a moral compass--a clear sense of the morals or virtues that guide their decisions. A firmly rooted moral compass inspires, leads, guides, and provides a solid foundation--and some sense of security--for organizations navigating massive or significant transformational changes, such as those required by the Affordable Care Act. In addition, "smaller" changes, such as consolidation, rationalization, and relocation of services, have a strong chance of succeeding in organizations that operate within a moral framework from which the organization can shape its future strategies and make important decisions. Finally, an organization's moral compass guides actions, reactions, and behaviors when unexpected or devastating events occur in the lives of consumers, employees, physicians, business partners, patients, families, and members of the community. The direction toward which its moral compass is pointing determines the types and quality of relationships it has with those key stakeholders, and those individuals and groups come to depend on what they have observed and know to be true about how the organization behaves in certain circumstances. While no organization can predict the future and all of the implications of change, key stakeholder groups need and want to know how they will be treated in the face of such change-whether expected or unexpected. In this sense, every organization must establish ways to evaluate the validity of its moral compass and develop--and adhere to--guidelines that determine how its members will behave, whether in ordinary circumstances; in the face of extraordinary, high-impact situations; or in times of massive transformational change. Above all, executive leaders must always be mindful that their own personal moral compass becomes their organization's moral compass.

Calibration of magnetic and celestial compass cues in migratory birds--a review of cue-conflict experiments.

PubMed

Muheim, Rachel; Moore, Frank R; Phillips, John B

2006-01-01

Migratory birds use multiple sources of compass information for orientation, including the geomagnetic field, the sun, skylight polarization patterns and star patterns. In this paper we review the results of cue-conflict experiments designed to determine the relative importance of the different compass mechanisms, and how directional information from these compass mechanisms is integrated. We focus on cue-conflict experiments in which the magnetic field was shifted in alignment relative to natural celestial cues. Consistent with the conclusions of earlier authors, our analyses suggest that during the premigratory season, celestial information is given the greatest salience and used to recalibrate the magnetic compass by both juvenile and adult birds. Sunset polarized light patterns from the region of the sky near the horizon appear to provide the calibration reference for the magnetic compass. In contrast, during migration, a majority of experiments suggest that birds rely on the magnetic field as the primary source of compass information and use it to calibrate celestial compass cues, i.e. the relative saliency of magnetic and celestial cues is reversed. An alternative possibility, however, is suggested by several experiments in which birds exposed to a cue conflict during migration appear to have recalibrated the magnetic compass, i.e. their response is similar to that of birds exposed to cue conflicts during the premigratory season. The general pattern to emerge from these analyses is that birds exposed to the cue conflict with a view of the entire sunset sky tended to recalibrate the magnetic compass, regardless of whether the cue conflict occurred during the premigratory or migratory period. In contrast, birds exposed to the cue conflict in orientation funnels and registration cages that restricted their view of the region of sky near the horizon (as was generally the case in experiments carried out during the migratory season) did not recalibrate the magnetic compass but, instead, used the magnetic compass to calibrate the other celestial compass systems. If access to critical celestial cues, rather than the timing of exposure to the cue conflict (i.e. premigratory vs migratory), determines whether recalibration of the magnetic compass occurs, this suggests that under natural conditions there may be a single calibration reference for all of the compass systems of migratory birds that is derived from sunset (and possibly also sunrise) polarized light cues from the region of sky near the horizon. In cue-conflict experiments carried out during the migratory season, there was also an interesting asymmetry in the birds' response to magnetic fields shifted clockwise and counterclockwise relative to celestial cues. We discuss two possible explanations for these differences: (1) lateral asymmetry in the role of the right and left eye in mediating light-dependent magnetic compass orientation and (2) interference from the spectral and intensity distribution of skylight at sunset with the response of the light-dependent magnetic compass.

46 CFR 109.415 - Retention of records after casualty.

Code of Federal Regulations, 2010 CFR

2010-10-01

... casualty. (a) The owner, agent, master, or person in charge of a unit for which a report of casualty is... of casualty. (6) Navigation work books. (7) Compass deviation cards. (8) Gyrocompass records. (9...) The radio log. (14) Personnel list. (15) Crane record book. (c) The owner, agent, master, or person in...

How Predictive Analytics and Choice Architecture Can Improve Student Success

ERIC Educational Resources Information Center

Denley, Tristan

2014-01-01

This article explores the challenges that students face in navigating the curricular structure of post-secondary degree programs, and how predictive analytics and choice architecture can play a role. It examines Degree Compass, a course recommendation system that successfully pairs current students with the courses that best fit their talents and…

US Army Land Navigation in the 21st Century

DTIC Science & Technology

2012-06-08

13 Military Professional School Papers ...should “alter doctrine and train forces to use information and IT [information technology] as aids, not crutches .”1 Vulnerabilities of the GPS system pose...prompted research into this topic: military training on electronic systems versus paper maps and compasses, recent successful destruction of a low

Orienteering for Sport and Pleasure.

ERIC Educational Resources Information Center

Bengtsson, Hans; Atkinson, George

This text presents the principles of the sport of orienteering (navigating through an unknown area using a map and compass as guide) and is useful to beginners, experienced orienteers, and "armchair" orienteers. Included in the text are: (1) a glossary of key words; (2) a basic introduction to, and history of, the sport; (3) description of the…

The quantum needle of the avian magnetic compass

PubMed Central

Hiscock, Hamish G.; Worster, Susannah; Kattnig, Daniel R.; Steers, Charlotte; Jin, Ye; Manolopoulos, David E.; Mouritsen, Henrik; Hore, P. J.

2016-01-01

Migratory birds have a light-dependent magnetic compass, the mechanism of which is thought to involve radical pairs formed photochemically in cryptochrome proteins in the retina. Theoretical descriptions of this compass have thus far been unable to account for the high precision with which birds are able to detect the direction of the Earth's magnetic field. Here we use coherent spin dynamics simulations to explore the behavior of realistic models of cryptochrome-based radical pairs. We show that when the spin coherence persists for longer than a few microseconds, the output of the sensor contains a sharp feature, referred to as a spike. The spike arises from avoided crossings of the quantum mechanical spin energy-levels of radicals formed in cryptochromes. Such a feature could deliver a heading precision sufficient to explain the navigational behavior of migratory birds in the wild. Our results (i) afford new insights into radical pair magnetoreception, (ii) suggest ways in which the performance of the compass could have been optimized by evolution, (iii) may provide the beginnings of an explanation for the magnetic disorientation of migratory birds exposed to anthropogenic electromagnetic noise, and (iv) suggest that radical pair magnetoreception may be more of a quantum biology phenomenon than previously realized. PMID:27044102

An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators.

PubMed

Mouritsen, Henrik; Derbyshire, Rachael; Stalleicken, Julia; Mouritsen, Ole Ø; Frost, Barrie J; Norris, D Ryan

2013-04-30

Monarch butterflies (Danaus plexippus) breeding in eastern North America are famous for their annual fall migration to their overwintering grounds in Mexico. However, the mechanisms they use to successfully reach these sites remain poorly understood. Here, we test whether monarchs are true navigators who can determine their location relative to their final destination using both a "compass" and a "map". Using flight simulators, we recorded the orientation of wild-caught monarchs in southwestern Ontario and found that individuals generally flew in a southwest direction toward the wintering grounds. When displaced 2,500 km to the west, the same individuals continued to fly in a general southwest direction, suggesting that monarchs use a simple vector-navigation strategy (i.e., use a specific compass bearing without compensating for displacement). Using over 5 decades of field data, we also show that the directional concentration and the angular SD of recoveries from tagged monarchs largely conformed to two mathematical models describing the directional distribution of migrants expected under a vector-navigation strategy. A third analysis of tagged recoveries shows that the increasing directionality of migration from north to south is largely because of the presence of geographic barriers that guide individuals toward overwintering sites. Our work suggests that monarchs breeding in eastern North America likely combine simple orientation mechanisms with geographic features that funnel them toward Mexican overwintering sites, a remarkable achievement considering that these butterflies weigh less than a gram and travel thousands of kilometers to a site they have never seen.

Polarized skylight navigation in insects: model and electrophysiology of e-vector coding by neurons in the central complex.

PubMed

Sakura, Midori; Lambrinos, Dimitrios; Labhart, Thomas

2008-02-01

Many insects exploit skylight polarization for visual compass orientation or course control. As found in crickets, the peripheral visual system (optic lobe) contains three types of polarization-sensitive neurons (POL neurons), which are tuned to different ( approximately 60 degrees diverging) e-vector orientations. Thus each e-vector orientation elicits a specific combination of activities among the POL neurons coding any e-vector orientation by just three neural signals. In this study, we hypothesize that in the presumed orientation center of the brain (central complex) e-vector orientation is population-coded by a set of "compass neurons." Using computer modeling, we present a neural network model transforming the signal triplet provided by the POL neurons to compass neuron activities coding e-vector orientation by a population code. Using intracellular electrophysiology and cell marking, we present evidence that neurons with the response profile of the presumed compass neurons do indeed exist in the insect brain: each of these compass neuron-like (CNL) cells is activated by a specific e-vector orientation only and otherwise remains silent. Morphologically, CNL cells are tangential neurons extending from the lateral accessory lobe to the lower division of the central body. Surpassing the modeled compass neurons in performance, CNL cells are insensitive to the degree of polarization of the stimulus between 99% and at least down to 18% polarization and thus largely disregard variations of skylight polarization due to changing solar elevations or atmospheric conditions. This suggests that the polarization vision system includes a gain control circuit keeping the output activity at a constant level.

Chemical compass model of avian magnetoreception.

PubMed

Maeda, Kiminori; Henbest, Kevin B; Cintolesi, Filippo; Kuprov, Ilya; Rodgers, Christopher T; Liddell, Paul A; Gust, Devens; Timmel, Christiane R; Hore, P J

2008-05-15

Approximately 50 species, including birds, mammals, reptiles, amphibians, fish, crustaceans and insects, are known to use the Earth's magnetic field for orientation and navigation. Birds in particular have been intensively studied, but the biophysical mechanisms that underlie the avian magnetic compass are still poorly understood. One proposal, based on magnetically sensitive free radical reactions, is gaining support despite the fact that no chemical reaction in vitro has been shown to respond to magnetic fields as weak as the Earth's ( approximately 50 muT) or to be sensitive to the direction of such a field. Here we use spectroscopic observation of a carotenoid-porphyrin-fullerene model system to demonstrate that the lifetime of a photochemically formed radical pair is changed by application of < or =50 microT magnetic fields, and to measure the anisotropic chemical response that is essential for its operation as a chemical compass sensor. These experiments establish the feasibility of chemical magnetoreception and give insight into the structural and dynamic design features required for optimal detection of the direction of the Earth's magnetic field.

Night-time neuronal activation of Cluster N in a day- and night-migrating songbird.

PubMed

Zapka, Manuela; Heyers, Dominik; Liedvogel, Miriam; Jarvis, Erich D; Mouritsen, Henrik

2010-08-01

Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds' eyes strongly reduces neuronal activation. These findings suggest that Cluster N processes light-dependent magnetic compass information in night-migrating songbirds. The aim of this study was to test if Cluster N is active during daytime migration. We used behavioural molecular mapping based on ZENK activation to investigate if Cluster N is active in the meadow pipit (Anthus pratensis), a day- and night-migratory species. We found that Cluster N of meadow pipits shows high neuronal activity under dim-light at night, but not under full room-light conditions during the day. These data suggest that, in day- and night-migratory meadow pipits, the light-dependent magnetic compass, which requires an active Cluster N, may only be used during night-time, whereas another magnetosensory mechanism and/or other reference system(s), like the sun or polarized light, may be used as primary orientation cues during the day.

In-flight angular alignment of inertial navigation systems by means of radio aids

NASA Technical Reports Server (NTRS)

Tanner, W.

1972-01-01

The principles involved in the angular alignment of the inertial reference by nondirectional data from radio aids are developed and compared with conventional methods of alignment such as gyro-compassing and pendulous vertical determination. The specific problem is considered of the space shuttle reentry and a proposed technique for the alignment of the inertial reference system some time before landing. A description is given of the digital simulation of a transponder interrogation system and of its interaction with the inertial navigation system. Data from reentry simulations are used to demonstrate the effectiveness of in-flight inertial system alignment. Concluding remarks refer to other potential applications such as space shuttle orbit insertion and air navigation of conventional aircraft.

Disease Compass- a navigation system for disease knowledge based on ontology and linked data techniques.

PubMed

Kozaki, Kouji; Yamagata, Yuki; Mizoguchi, Riichiro; Imai, Takeshi; Ohe, Kazuhiko

2017-06-19

Medical ontologies are expected to contribute to the effective use of medical information resources that store considerable amount of data. In this study, we focused on disease ontology because the complicated mechanisms of diseases are related to concepts across various medical domains. The authors developed a River Flow Model (RFM) of diseases, which captures diseases as the causal chains of abnormal states. It represents causes of diseases, disease progression, and downstream consequences of diseases, which is compliant with the intuition of medical experts. In this paper, we discuss a fact repository for causal chains of disease based on the disease ontology. It could be a valuable knowledge base for advanced medical information systems. We developed the fact repository for causal chains of diseases based on our disease ontology and abnormality ontology. This section summarizes these two ontologies. It is developed as linked data so that information scientists can access it using SPARQL queries through an Resource Description Framework (RDF) model for causal chain of diseases. We designed the RDF model as an implementation of the RFM for the fact repository based on the ontological definitions of the RFM. 1554 diseases and 7080 abnormal states in six major clinical areas, which are extracted from the disease ontology, are published as linked data (RDF) with SPARQL endpoint (accessible API). Furthermore, the authors developed Disease Compass, a navigation system for disease knowledge. Disease Compass can browse the causal chains of a disease and obtain related information, including abnormal states, through two web services that provide general information from linked data, such as DBpedia, and 3D anatomical images. Disease Compass can provide a complete picture of disease-associated processes in such a way that fits with a clinician's understanding of diseases. Therefore, it supports user exploration of disease knowledge with access to pertinent information from a variety of sources.

Navigating the Seas of Policy.

ERIC Educational Resources Information Center

Cunningham, Stephanie; Kennedy, Steve; McAlonan, Susan; Hotchkiss, Heather

As the sun, moon, and stars helped sea captains to navigate, policy (defined as a formalized idea to encourage change) indicates general direction and speed but does not establish a specific approach to achieve implementation. Formal and informal policies have advantages and disadvantages. These are steps in navigating policy formation: identify…

Update on GPS Modernization Efforts

DTIC Science & Technology

2015-06-02

Bilateral Agreements • Adjacent Band Interference • International Committee On Global Navigation Satellite Systems ( GNSS ) Department of...Receivers • Distribute PRNs for the World - 120 for US and 90 for GNSS International Cooperation • 57 Authorized Allied Users - 25+ Years of...Cooperation • GNSS -Europe - Galilee - China - COMPASS -Russia - GLONASS - Japan - QZSS - India- IRNSS 5 GPS Modernization Program SPACE AND MISSILE

The Vita Activa as Compass: Navigating Uncertainty in Teaching with Hannah Arendt

ERIC Educational Resources Information Center

Rogers, Carrie Ann Barnes

2010-01-01

This dissertation is an exploration of stories of uncertainty in the lives of elementary teachers and the value that the ideas of Hannah Arendt lend to the discussion around uncertainty. In "The Human Condition" (1958) Hannah Arendt theorizes the life of action, the "vita activa". Arendtian action is inherently uncertain because to be "capable of…

Transmedulla Neurons in the Sky Compass Network of the Honeybee (Apis mellifera) Are a Possible Site of Circadian Input

PubMed Central

Zeller, Maximilian; Held, Martina; Bender, Julia; Berz, Annuska; Heinloth, Tanja; Hellfritz, Timm; Pfeiffer, Keram

2015-01-01

Honeybees are known for their ability to use the sun’s azimuth and the sky’s polarization pattern for spatial orientation. Sky compass orientation in bees has been extensively studied at the behavioral level but our knowledge about the underlying neuronal systems and mechanisms is very limited. Electrophysiological studies in other insect species suggest that neurons of the sky compass system integrate information about the polarization pattern of the sky, its chromatic gradient, and the azimuth of the sun. In order to obtain a stable directional signal throughout the day, circadian changes between the sky polarization pattern and the solar azimuth must be compensated. Likewise, the system must be modulated in a context specific way to compensate for changes in intensity, polarization and chromatic properties of light caused by clouds, vegetation and landscape. The goal of this study was to identify neurons of the sky compass pathway in the honeybee brain and to find potential sites of circadian and neuromodulatory input into this pathway. To this end we first traced the sky compass pathway from the polarization-sensitive dorsal rim area of the compound eye via the medulla and the anterior optic tubercle to the lateral complex using dye injections. Neurons forming this pathway strongly resembled neurons of the sky compass pathway in other insect species. Next we combined tracer injections with immunocytochemistry against the circadian neuropeptide pigment dispersing factor and the neuromodulators serotonin, and γ-aminobutyric acid. We identified neurons, connecting the dorsal rim area of the medulla to the anterior optic tubercle, as a possible site of neuromodulation and interaction with the circadian system. These neurons have conspicuous spines in close proximity to pigment dispersing factor-, serotonin-, and GABA-immunoreactive neurons. Our data therefore show for the first time a potential interaction site between the sky compass pathway and the circadian clock. PMID:26630286

Navigation.

PubMed

Wiltschko, Roswitha

2017-07-01

Experiments with migrating birds displaced during autumn migration outside their normal migration corridor reveal two different navigational strategies: adult migrants compensate for the displacement, and head towards their traditional wintering areas, whereas young first-time migrants continue in their migratory direction. Young birds are guided to their still unknown goal by a genetically coded migration program that indicates duration and direction(s) of the migratory flight by controlling the amount of migratory restlessness and the compass course(s) with respect to the geomagnetic field and celestial rotation. Adult migrants that have already wintered and are familiar with the goal area approach the goal by true navigation, specifically heading towards it and changing their course correspondingly after displacement. During their first journey, young birds experience the distribution of potential navigational factors en route and in their winter home, which allows them to truly navigate on their next migrations. The navigational factors used appear to include magnetic intensity as a component in their multi-modal navigational 'map'; olfactory input is also involved, even if it is not yet entirely clear in what way. The mechanisms of migratory birds for true navigation over long distances appear to be in principle similar to those discussed for by homing pigeons.

Testing avian compass calibration: comparative experiments with diurnal and nocturnal passerine migrants in South Sweden

PubMed Central

Åkesson, Susanne; Odin, Catharina; Hegedüs, Ramón; Ilieva, Mihaela; Sjöholm, Christoffer; Farkas, Alexandra; Horváth, Gábor

2015-01-01

ABSTRACT Cue-conflict experiments were performed to study the compass calibration of one predominantly diurnal migrant, the dunnock (Prunella modularis), and two species of nocturnal passerine migrants, the sedge warbler (Acrocephalus schoenobaenus), and the European robin (Erithacus rubecula) during autumn migration in South Sweden. The birds' orientation was recorded in circular cages under natural clear and simulated overcast skies in the local geomagnetic field, and thereafter the birds were exposed to a cue-conflict situation where the horizontal component of the magnetic field (mN) was shifted +90° or −90° at two occasions, one session starting shortly after sunrise and the other ca. 90 min before sunset and lasting for 60 min. The patterns of the degree and angle of skylight polarization were measured by full-sky imaging polarimetry during the cue-conflict exposures and orientation tests. All species showed orientation both under clear and overcast skies that correlated with the expected migratory orientation towards southwest to south. For the European robin the orientation under clear skies was significantly different from that recorded under overcast skies, showing a tendency that the orientation under clear skies was influenced by the position of the Sun at sunset resulting in more westerly orientation. This sun attraction was not observed for the sedge warbler and the dunnock, both orientating south. All species showed similar orientation after the cue-conflict as compared to the preferred orientation recorded before the cue-conflict, with the clearest results in the European robin and thus, the results did not support recalibration of the celestial nor the magnetic compasses as a result of the cue-conflict exposure. PMID:25505150

How to use the Sun-Earth Lagrange points for fundamental physics and navigation

NASA Astrophysics Data System (ADS)

Tartaglia, A.; Lorenzini, E. C.; Lucchesi, D.; Pucacco, G.; Ruggiero, M. L.; Valko, P.

2018-01-01

We illustrate the proposal, nicknamed LAGRANGE, to use spacecraft, located at the Sun-Earth Lagrange points, as a physical reference frame. Performing time of flight measurements of electromagnetic signals traveling on closed paths between the points, we show that it would be possible: (a) to refine gravitational time delay knowledge due both to the Sun and the Earth; (b) to detect the gravito-magnetic frame dragging of the Sun, so deducing information about the interior of the star; (c) to check the possible existence of a galactic gravitomagnetic field, which would imply a revision of the properties of a dark matter halo; (d) to set up a relativistic positioning and navigation system at the scale of the inner solar system. The paper presents estimated values for the relevant quantities and discusses the feasibility of the project analyzing the behavior of the space devices close to the Lagrange points.

On the trail of Vikings with polarized skylight: experimental study of the atmospheric optical prerequisites allowing polarimetric navigation by Viking seafarers.

PubMed

Horváth, Gábor; Barta, András; Pomozi, István; Suhai, Bence; Hegedüs, Ramón; Akesson, Susanne; Meyer-Rochow, Benno; Wehner, Rüdiger

2011-03-12

Between AD 900 and AD 1200 Vikings, being able to navigate skillfully across the open sea, were the dominant seafarers of the North Atlantic. When the Sun was shining, geographical north could be determined with a special sundial. However, how the Vikings could have navigated in cloudy or foggy situations, when the Sun's disc was unusable, is still not fully known. A hypothesis was formulated in 1967, which suggested that under foggy or cloudy conditions, Vikings might have been able to determine the azimuth direction of the Sun with the help of skylight polarization, just like some insects. This hypothesis has been widely accepted and is regularly cited by researchers, even though an experimental basis, so far, has not been forthcoming. According to this theory, the Vikings could have determined the direction of the skylight polarization with the help of an enigmatic birefringent crystal, functioning as a linearly polarizing filter. Such a crystal is referred to as 'sunstone' in one of the Viking's sagas, but its exact nature is unknown. Although accepted by many, the hypothesis of polarimetric navigation by Vikings also has numerous sceptics. In this paper, we summarize the results of our own celestial polarization measurements and psychophysical laboratory experiments, in which we studied the atmospheric optical prerequisites of possible sky-polarimetric navigation in Tunisia, Finland, Hungary and the high Arctic.

On the trail of Vikings with polarized skylight: experimental study of the atmospheric optical prerequisites allowing polarimetric navigation by Viking seafarers

PubMed Central

Horváth, Gábor; Barta, András; Pomozi, István; Suhai, Bence; Hegedüs, Ramón; Åkesson, Susanne; Meyer-Rochow, Benno; Wehner, Rüdiger

2011-01-01

Between AD 900 and AD 1200 Vikings, being able to navigate skillfully across the open sea, were the dominant seafarers of the North Atlantic. When the Sun was shining, geographical north could be determined with a special sundial. However, how the Vikings could have navigated in cloudy or foggy situations, when the Sun's disc was unusable, is still not fully known. A hypothesis was formulated in 1967, which suggested that under foggy or cloudy conditions, Vikings might have been able to determine the azimuth direction of the Sun with the help of skylight polarization, just like some insects. This hypothesis has been widely accepted and is regularly cited by researchers, even though an experimental basis, so far, has not been forthcoming. According to this theory, the Vikings could have determined the direction of the skylight polarization with the help of an enigmatic birefringent crystal, functioning as a linearly polarizing filter. Such a crystal is referred to as ‘sunstone’ in one of the Viking's sagas, but its exact nature is unknown. Although accepted by many, the hypothesis of polarimetric navigation by Vikings also has numerous sceptics. In this paper, we summarize the results of our own celestial polarization measurements and psychophysical laboratory experiments, in which we studied the atmospheric optical prerequisites of possible sky-polarimetric navigation in Tunisia, Finland, Hungary and the high Arctic. PMID:21282181

Quadrant to Measure the Sun's Altitude

ERIC Educational Resources Information Center

Windsor, A Morgan, Jr.

2013-01-01

The changing altitude of the Sun (either over the course of a day or longer periods) is a phenomenon that students do not normally appreciate. However, the altitude of the Sun affects many topics in disciplines as diverse as astronomy, meteorology, navigation, or horology, such as the basis for seasons, determination of latitude and longitude, or…

Horizon Based Orientation Estimation for Planetary Surface Navigation

NASA Technical Reports Server (NTRS)

Bouyssounouse, X.; Nefian, A. V.; Deans, M.; Thomas, A.; Edwards, L.; Fong, T.

2016-01-01

Planetary rovers navigate in extreme environments for which a Global Positioning System (GPS) is unavailable, maps are restricted to relatively low resolution provided by orbital imagery, and compass information is often lacking due to weak or not existent magnetic fields. However, an accurate rover localization is particularly important to achieve the mission success by reaching the science targets, avoiding negative obstacles visible only in orbital maps, and maintaining good communication connections with ground. This paper describes a horizon solution for precise rover orientation estimation. The detected horizon in imagery provided by the on board navigation cameras is matched with the horizon rendered over the existing terrain model. The set of rotation parameters (roll, pitch yaw) that minimize the cost function between the two horizon curves corresponds to the rover estimated pose.

Electron Spin Relaxation Can Enhance the Performance of a Cryptochrome-Based Magnetic Compass Sensor

DTIC Science & Technology

2016-08-19

quantumbiology,migratory birds, animal navigation, radical pairmechanism Supplementarymaterial for this article is available online Abstract The radical ...certain spin relaxationmechanisms can enhance its performance.We focus on the flavin–tryptophan radical pair in cryptochrome, currently the only...candidatemagnetoreceptor molecule. Correlation functions for fluctuations in the distance between the two radicals in Arabidopsis thaliana cryptochrome

Harbour seals (Phoca vitulina) can steer by the stars.

PubMed

Mauck, Björn; Gläser, Nele; Schlosser, Wolfhard; Dehnhardt, Guido

2008-10-01

Offshore orientation in marine mammals is still a mystery. For visual orientation during night-time foraging and travelling in the open seas, seals cannot rely on distant terrestrial landmarks, and thus might use celestial cues as repeatedly shown for nocturnally migrating birds. Although seals detect enough stars to probably allow for astronavigation, it was unclear whether they can orient by the night sky. The widely accepted cognitive mechanism for bird night-time orientation by celestial cues is a time-independent star compass with learned geometrical star configurations used to pinpoint north as the rotational centre of the starry sky while there is no conclusive evidence for a time-compensated star compass or true star navigation. Here, we present results for two harbour seals orienting in a custom made swimming planetarium. Both seals learned to highly accurately identify a lodestar out of a pseudo-randomly oriented, realistic projection of the northern hemisphere night sky. Providing the first evidence for star orientation capability in a marine mammal, our seals' outstanding directional precision would allow them to steer by following lodestars of learned star courses, a celestial orientation mechanism that has been known to be used by Polynesian navigators but has not been considered for animals yet.

A new navigational mechanism mediated by ant ocelli.

PubMed

Schwarz, Sebastian; Wystrach, Antoine; Cheng, Ken

2011-12-23

Many animals rely on path integration for navigation and desert ants are the champions. On leaving the nest, ants continuously integrate their distance and direction of travel so that they always know their current distance and direction from the nest and can take a direct path to home. Distance information originates from a step-counter and directional information is based on a celestial compass. So far, it has been assumed that the directional information obtained from ocelli contribute to a single global path integrator, together with directional information from the dorsal rim area (DRA) of the compound eyes and distance information from the step-counter. Here, we show that ocelli mediate a distinct compass from that mediated by the compound eyes. After travelling a two-leg outbound route, untreated foragers headed towards the nest direction, showing that both legs of the route had been integrated. In contrast, foragers with covered compound eyes but uncovered ocelli steered in the direction opposite to the last leg of the outbound route. Our findings suggest that, unlike the DRA, ocelli cannot by themselves mediate path integration. Instead, ocelli mediate a distinct directional system, which buffers the most recent leg of a journey.

Use of the sun as a heading indicator when caching and recovering in a wild rodent

PubMed Central

Samson, Jamie; Manser, Marta B.

2016-01-01

A number of diurnal species have been shown to use directional information from the sun to orientate. The use of the sun in this way has been suggested to occur in either a time-dependent (relying on specific positional information) or a time-compensated manner (a compass that adjusts itself over time with the shifts in the sun’s position). However, some interplay may occur between the two where a species could also use the sun in a time-limited way, whereby animals acquire certain information about the change of position, but do not show full compensational abilities. We tested whether Cape ground squirrels (Xerus inauris) use the sun as an orientation marker to provide information for caching and recovery. This species is a social sciurid that inhabits arid, sparsely vegetated habitats in Southern Africa, where the sun is nearly always visible during the diurnal period. Due to the lack of obvious landmarks, we predicted that they might use positional cues from the sun in the sky as a reference point when caching and recovering food items. We provide evidence that Cape ground squirrels use information from the sun’s position while caching and reuse this information in a time-limited way when recovering these caches. PMID:27580797

Perceptual Strategies of Pigeons to Detect a Rotational Centre—A Hint for Star Compass Learning?

PubMed Central

Helduser, Sascha; Mouritsen, Henrik; Güntürkün, Onur

2015-01-01

Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy. PMID:25807499

Steering intermediate courses: desert ants combine information from various navigational routines.

PubMed

Wehner, Rüdiger; Hoinville, Thierry; Cruse, Holk; Cheng, Ken

2016-07-01

A number of systems of navigation have been studied in some detail in insects. These include path integration, a system that keeps track of the straight-line distance and direction travelled on the current trip, the use of panoramic landmarks and scenery for orientation, and systematic searching. A traditional view is that only one navigational system is in operation at any one time, with different systems running in sequence depending on the context and conditions. We review selected data suggesting that often, different navigational cues (e.g., compass cues) and different systems of navigation are in operation simultaneously in desert ant navigation. The evidence suggests that all systems operate in parallel forming a heterarchical network. External and internal conditions determine the weights to be accorded to each cue and system. We also show that a model of independent modules feeding into a central summating device, the Navinet model, can in principle account for such data. No central executive processor is necessary aside from a weighted summation of the different cues and systems. Such a heterarchy of parallel systems all in operation represents a new view of insect navigation that has already been expressed informally by some authors.

Bats respond to polarity of a magnetic field.

PubMed

Wang, Yinan; Pan, Yongxin; Parsons, Stuart; Walker, Michael; Zhang, Shuyi

2007-11-22

Bats have been shown to use information from the Earth's magnetic field during orientation. However, the mechanism underlying this ability remains unknown. In this study we investigated whether bats possess a polarity- or inclination-based compass that could be used in orientation. We monitored the hanging position of adult Nyctalus plancyi in the laboratory in the presence of an induced magnetic field of twice Earth-strength. When under the influence of a normally aligned induced field the bats showed a significant preference for hanging at the northern end of their roosting basket. When the vertical component of the field was reversed, the bats remained at the northern end of the basket. However, when the horizontal component of the field was reversed, the bats changed their positions and hung at the southern end of the basket. Based on these results, we conclude that N. plancyi, unlike all other non-mammalian vertebrates tested to date, uses a polarity-based compass during orientation in the roost, and that the same compass is also likely to underlie bats' long-distance navigation abilities.

A Dual Frequency Carrier Phase Error Difference Checking Algorithm for the GNSS Compass.

PubMed

Liu, Shuo; Zhang, Lei; Li, Jian

2016-11-24

The performance of the Global Navigation Satellite System (GNSS) compass is related to the quality of carrier phase measurement. How to process the carrier phase error properly is important to improve the GNSS compass accuracy. In this work, we propose a dual frequency carrier phase error difference checking algorithm for the GNSS compass. The algorithm aims at eliminating large carrier phase error in dual frequency double differenced carrier phase measurement according to the error difference between two frequencies. The advantage of the proposed algorithm is that it does not need additional environment information and has a good performance on multiple large errors compared with previous research. The core of the proposed algorithm is removing the geographical distance from the dual frequency carrier phase measurement, then the carrier phase error is separated and detectable. We generate the Double Differenced Geometry-Free (DDGF) measurement according to the characteristic that the different frequency carrier phase measurements contain the same geometrical distance. Then, we propose the DDGF detection to detect the large carrier phase error difference between two frequencies. The theoretical performance of the proposed DDGF detection is analyzed. An open sky test, a manmade multipath test and an urban vehicle test were carried out to evaluate the performance of the proposed algorithm. The result shows that the proposed DDGF detection is able to detect large error in dual frequency carrier phase measurement by checking the error difference between two frequencies. After the DDGF detection, the accuracy of the baseline vector is improved in the GNSS compass.

Solar oscillation time delay measurement assisted celestial navigation method

NASA Astrophysics Data System (ADS)

Ning, Xiaolin; Gui, Mingzhen; Zhang, Jie; Fang, Jiancheng; Liu, Gang

2017-05-01

Solar oscillation, which causes the sunlight intensity and spectrum frequency change, has been studied in great detail, both observationally and theoretically. In this paper, owing to the existence of solar oscillation, the time delay between the sunlight coming from the Sun directly and the sunlight reflected by the other celestial body such as the satellite of planet or asteroid can be obtained with two optical power meters. Because the solar oscillation time delay is determined by the relative positions of the spacecraft, reflective celestial body and the Sun, it can be adopted as the navigation measurement to estimate the spacecraft's position. The navigation accuracy of single solar oscillation time delay navigation system depends on the time delay measurement accuracy, and is influenced by the distance between spacecraft and reflective celestial body. In this paper, we combine it with the star angle measurement and propose a solar oscillation time delay measurement assisted celestial navigation method for deep space exploration. Since the measurement model of time delay is an implicit function, the Implicit Unscented Kalman Filter (IUKF) is applied. Simulations demonstrate the effectiveness and superiority of this method.

Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions

NASA Astrophysics Data System (ADS)

Horváth, Gábor; Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

2017-02-01

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d* for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d > d* is satisfied. Using full-sky imaging polarimetry, we measured the d-pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ. From the measured d-patterns of a given sky we determined the proportion P of the sky for which d > d*. We obtained that P is the largest at low solar elevations θ ≈ 0° and under totally or nearly clear skies with cloud coverage ρ = 0%, when the sun's position is already easily determined. If the sun is below the horizon (-5° ≤ θ < 0°) during twilight, P = 76.17 ± 4.18% for dmin∗=23 % under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes.

Autonomous vehicle navigation utilizing fuzzy controls concepts for a next generation wheelchair.

PubMed

Hansen, J D; Barrett, S F; Wright, C H G; Wilcox, M

2008-01-01

Three different positioning techniques were investigated to create an autonomous vehicle that could accurately navigate towards a goal: Global Positioning System (GPS), compass dead reckoning, and Ackerman steering. Each technique utilized a fuzzy logic controller that maneuvered a four-wheel car towards a target. The reliability and the accuracy of the navigation methods were investigated by modeling the algorithms in software and implementing them in hardware. To implement the techniques in hardware, positioning sensors were interfaced to a remote control car and a microprocessor. The microprocessor utilized the sensor measurements to orient the car with respect to the target. Next, a fuzzy logic control algorithm adjusted the front wheel steering angle to minimize the difference between the heading and bearing. After minimizing the heading error, the car maintained a straight steering angle along its path to the final destination. The results of this research can be used to develop applications that require precise navigation. The design techniques can also be implemented on alternate platforms such as a wheelchair to assist with autonomous navigation.

Terrestrial Magnetism in Ottoman Empire: Documents and Measurements

NASA Astrophysics Data System (ADS)

Ozcep, Ferhat

2016-04-01

In the modern sense, geophysics started with geomagnetic works in the 1600s in Ottoman geography. The period between 1600 and 1800 includes the measurement of magnetic declination, inclination and magnetic field strength. Before these years, there is a little information, such as how to use a compass, in the Kitab-i Bahriye (the Book of Navigation) of Piri Reis, who is one of the most important mariners of the Ottoman Empire. However, this may not mean that magnetic declination was generally understood. The first Turkish scientific book relating to terrestrial magnetism is the book of Fuyuzat-i Miknatissiye that was translated by Ibrahim Müteferrika and printed in 1731. The subject of this book is earth's magnetism. Magnetic compass was mentioned in several books. These areMuhammed al Awfi's "Jami al- Hikayat" (translated into Turkish by Ibn Arabşah); Piri Reis's Kitab-I Bahriye (The Book of "Navigation" or "Seafaring" or "Sea"); Seydi Ali Reis's "Risale-i Mirat-I Kainat min Alat-I Irtifa" (The Treatise called the Mirror of Universe according to the instrument for measuring Altitude) and Kitab Al-"Muhit" Fi˙Ilm'al-Eflak Va'l Abhur (Book of the Regional Seas and the Science of Astronomy and Navigation). There are two original magnetic declination determinations in Istanbul in 1727 and 1893 by Ottoman Turks. Also, many geomagnetic measurements between 1600 and 1917 were carried out during international campaigns in Ottoman geography.This study was carried out in History and Philosophy of Science, University of Cambridge and supported by Istanbul University Reseach Project Unite (project Numbver: IRP-49162).

Honeybee navigation: following routes using polarized-light cues

PubMed Central

Kraft, P.; Evangelista, C.; Dacke, M.; Labhart, T.; Srinivasan, M. V.

2011-01-01

While it is generally accepted that honeybees (Apis mellifera) are capable of using the pattern of polarized light in the sky to navigate to a food source, there is little or no direct behavioural evidence that they actually do so. We have examined whether bees can be trained to find their way through a maze composed of four interconnected tunnels, by using directional information provided by polarized light illumination from the ceilings of the tunnels. The results show that bees can learn this task, thus demonstrating directly, and for the first time, that bees are indeed capable of using the polarized-light information in the sky as a compass to steer their way to a food source. PMID:21282174

Backtracking behaviour in lost ants: an additional strategy in their navigational toolkit

PubMed Central

Wystrach, Antoine; Schwarz, Sebastian; Baniel, Alice; Cheng, Ken

2013-01-01

Ants use multiple sources of information to navigate, but do not integrate all this information into a unified representation of the world. Rather, the available information appears to serve three distinct main navigational systems: path integration, systematic search and the use of learnt information—mainly via vision. Here, we report on an additional behaviour that suggests a supplemental system in the ant's navigational toolkit: ‘backtracking’. Homing ants, having almost reached their nest but, suddenly displaced to unfamiliar areas, did not show the characteristic undirected headings of systematic searches. Instead, these ants backtracked in the compass direction opposite to the path that they had just travelled. The ecological function of this behaviour is clear as we show it increases the chances of returning to familiar terrain. Importantly, the mechanistic implications of this behaviour stress an extra level of cognitive complexity in ant navigation. Our results imply: (i) the presence of a type of ‘memory of the current trip’ allowing lost ants to take into account the familiar view recently experienced, and (ii) direct sharing of information across different navigational systems. We propose a revised architecture of the ant's navigational toolkit illustrating how the different systems may interact to produce adaptive behaviours. PMID:23966644

Acquisition and cruise sensing for attitude control

NASA Technical Reports Server (NTRS)

Pace, G. D., Jr.; Schmidt, L. F.

1977-01-01

Modified wideangle analog cruise sun sensor coupled with changes in optic attitude correction capabilities, eliminate need of acquisition and sun gate sensors, making on-course navigation of spacecraft flying interplanetary missions less risky and costly. Operational characteristics potentially make system applicable to guidance and control of solar energy collection systems.

Magnetic maps in animals: nature's GPS.

PubMed

Lohmann, Kenneth J; Lohmann, Catherine M F; Putman, Nathan F

2007-11-01

Diverse animals detect the Earth's magnetic field and use it as a cue in orientation and navigation. Most research on magnetoreception has focused on the directional or ;compass' information that can be extracted from the Earth's field. Because the field varies predictably across the surface of the globe, however, it also provides a potential source of positional or 'map' information, which some animals use to steer themselves along migratory pathways or to navigate toward specific target areas. The use of magnetic positional information has been demonstrated in several diverse animals including sea turtles, spiny lobsters, newts and birds, suggesting that such systems are phylogenetically widespread and can function over a wide range of spatial scales. These ;magnetic maps' have not yet been fully characterized. They may be organized in several fundamentally different ways, some of which bear little resemblance to human maps, and they may also be used in conjunction with unconventional navigational strategies.

Draper Laboratory small autonomous aerial vehicle

NASA Astrophysics Data System (ADS)

DeBitetto, Paul A.; Johnson, Eric N.; Bosse, Michael C.; Trott, Christian A.

1997-06-01

The Charles Stark Draper Laboratory, Inc. and students from Massachusetts Institute of Technology and Boston University have cooperated to develop an autonomous aerial vehicle that won the 1996 International Aerial Robotics Competition. This paper describes the approach, system architecture and subsystem designs for the entry. This entry represents a combination of many technology areas: navigation, guidance, control, vision processing, human factors, packaging, power, real-time software, and others. The aerial vehicle, an autonomous helicopter, performs navigation and control functions using multiple sensors: differential GPS, inertial measurement unit, sonar altimeter, and a flux compass. The aerial transmits video imagery to the ground. A ground based vision processor converts the image data into target position and classification estimates. The system was designed, built, and flown in less than one year and has provided many lessons about autonomous vehicle systems, several of which are discussed. In an appendix, our current research in augmenting the navigation system with vision- based estimates is presented.

Central projections of sensory systems involved in honey bee dance language communication.

PubMed

Brockmann, Axel; Robinson, Gene E

2007-01-01

Honey bee dance language is a unique and complex form of animal communication used to inform nest mates in the colony about the specific location of food sources or new nest sites. Five different sensory systems have been implicated in acquiring and communicating the information necessary for dance language communication. We present results from neuronal tracer studies identifying the central projections from four of the five. Sensory neurons of the dorsal rim area of the compound eyes, involved in acquiring sun-compass based information, project to the dorsal-most part of the medulla. Sensory neurons of the neck hair plates, required to transpose sun-compass based information to gravity-based information in the dark hive, project to the dorsal labial neuromere of the subesophageal ganglion. Sensory neurons from the antennal joint hair sensilla and the Johnston's organ, which perceive information on dance direction and distance from mechanostimuli generated by abdomen waggling and wing vibration, project to the deutocerebral dorsal lobe and the subesophageal ganglion, and the posterior protocerebrum, respectively. We found no 'dance-specific' projections relative to those previously described for drone and queen honey bees and other insect species that do not exhibit dance communication. We suggest that the evolution of dance language communication was likely based on the modification of central neural pathways associated with path integration, the capability to calculate distance, and directional information during flight. Copyright 2007 S. Karger AG, Basel.

Support for redistribution is shaped by compassion, envy, and self-interest, but not a taste for fairness.

PubMed

Sznycer, Daniel; Lopez Seal, Maria Florencia; Sell, Aaron; Lim, Julian; Porat, Roni; Shalvi, Shaul; Halperin, Eran; Cosmides, Leda; Tooby, John

2017-08-01

Why do people support economic redistribution? Hypotheses include inequity aversion, a moral sense that inequality is intrinsically unfair, and cultural explanations such as exposure to and assimilation of culturally transmitted ideologies. However, humans have been interacting with worse-off and better-off individuals over evolutionary time, and our motivational systems may have been naturally selected to navigate the opportunities and challenges posed by such recurrent interactions. We hypothesize that modern redistribution is perceived as an ancestral scene involving three notional players: the needy other, the better-off other, and the actor herself. We explore how three motivational systems-compassion, self-interest, and envy-guide responses to the needy other and the better-off other, and how they pattern responses to redistribution. Data from the United States, the United Kingdom, India, and Israel support this model. Endorsement of redistribution is independently predicted by dispositional compassion, dispositional envy, and the expectation of personal gain from redistribution. By contrast, a taste for fairness, in the sense of ( i ) universality in the application of laws and standards, or ( ii ) low variance in group-level payoffs, fails to predict attitudes about redistribution.

Support for redistribution is shaped by compassion, envy, and self-interest, but not a taste for fairness

PubMed Central

Lopez Seal, Maria Florencia; Sell, Aaron; Lim, Julian; Porat, Roni; Halperin, Eran; Cosmides, Leda; Tooby, John

2017-01-01

Why do people support economic redistribution? Hypotheses include inequity aversion, a moral sense that inequality is intrinsically unfair, and cultural explanations such as exposure to and assimilation of culturally transmitted ideologies. However, humans have been interacting with worse-off and better-off individuals over evolutionary time, and our motivational systems may have been naturally selected to navigate the opportunities and challenges posed by such recurrent interactions. We hypothesize that modern redistribution is perceived as an ancestral scene involving three notional players: the needy other, the better-off other, and the actor herself. We explore how three motivational systems—compassion, self-interest, and envy—guide responses to the needy other and the better-off other, and how they pattern responses to redistribution. Data from the United States, the United Kingdom, India, and Israel support this model. Endorsement of redistribution is independently predicted by dispositional compassion, dispositional envy, and the expectation of personal gain from redistribution. By contrast, a taste for fairness, in the sense of (i) universality in the application of laws and standards, or (ii) low variance in group-level payoffs, fails to predict attitudes about redistribution. PMID:28716928

A Snapshot-Based Mechanism for Celestial Orientation.

PubMed

El Jundi, Basil; Foster, James J; Khaldy, Lana; Byrne, Marcus J; Dacke, Marie; Baird, Emily

2016-06-06

In order to protect their food from competitors, ball-rolling dung beetles detach a piece of dung from a pile, shape it into a ball, and roll it away along a straight path [1]. They appear to rely exclusively on celestial compass cues to maintain their bearing [2-8], but the mechanism that enables them to use these cues for orientation remains unknown. Here, we describe the orientation strategy that allows dung beetles to use celestial cues in a dynamic fashion. We tested the underlying orientation mechanism by presenting beetles with a combination of simulated celestial cues (sun, polarized light, and spectral cues). We show that these animals do not rely on an innate prediction of the natural geographical relationship between celestial cues, as other navigating insects seem to [9, 10]. Instead, they appear to form an internal representation of the prevailing celestial scene, a "celestial snapshot," even if that scene represents a physical impossibility for the real sky. We also find that the beetles are able to maintain their bearing with respect to the presented cues only if the cues are visible when the snapshot is taken. This happens during the "dance," a behavior in which the beetle climbs on top of its ball and rotates about its vertical axis [11]. This strategy for reading celestial signals is a simple but efficient mechanism for straight-line orientation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mars Rover Navigation Results Using Sun Sensor Heading Determination

NASA Technical Reports Server (NTRS)

Volpe, Richard

1998-01-01

Upcoming missions to the surface of Mars will use mobile robots to traverse long distances from the landing site. To prepare for these missions, the prototype rover, Rocky 7, has been tested in desert field trials conducted with a team of planetary scientists. While several new capabilities have been demonstrated, foremost among these was sun-sensor based traversal of natural terrain totaling a distance of one kilometer. This paper describes navigation results obtained in the field tests, where cross-track error was only 6% of distance traveled. Comparison with previous results of other planetary rover systems shows this to be a significant improvement.

Bats Can Use Magnetic Compass in Foraging Behavior

NASA Astrophysics Data System (ADS)

Tian, L.; Zhang, B.; Pan, Y.; Zhu, R.

2016-12-01

Foraging plays an important role in an animal's ability to survive and reproduce. It is widely recognized that many animals and microorganisms can use geomagnetic compass in migration or homing orientation. Among them, bats, the only flying mammals, can use the magnetic compass in migrating orientations. For instance, we found the migratory microbat, Nyctalus plancyi, could use the magnetic polarity compass in roosting orientation under the strength range at least from a much weaker magnetic field than the present-day geomagnetic field (as low as 10 μT) to up to stronger magnetic field (100 μT). This high sensitivity to magnetic fields intensity may explain how magnetic orientation could have long-term evolved in bats even as the Earth's magnetic field strength varied as the polarity reversed many times in the past. Recently, we carried out foraging behavioral experiments on N. plancyi under various magnetic field conditions. Interestingly, it has shown that, although the auditory including echolocation, or olfactory sense may be the primary methods for seeking food under totally dark circumstance, the bats showed preferred foraging orientations at the magnetic north-south directions when any other sensory cues are insufficient for location of the food. It confirmed that bats could optimally use multiple directional cues including the geomagnetic field in their foraging in field. When bats foraging, they would navigate along the magnetic field direction if there were no direct sensory cues. As it gets close, the direct cues from food would guide them to the food.

Microglomerular Synaptic Complexes in the Sky-Compass Network of the Honeybee Connect Parallel Pathways from the Anterior Optic Tubercle to the Central Complex.

PubMed

Held, Martina; Berz, Annuska; Hensgen, Ronja; Muenz, Thomas S; Scholl, Christina; Rössler, Wolfgang; Homberg, Uwe; Pfeiffer, Keram

2016-01-01

While the ability of honeybees to navigate relying on sky-compass information has been investigated in a large number of behavioral studies, the underlying neuronal system has so far received less attention. The sky-compass pathway has recently been described from its input region, the dorsal rim area (DRA) of the compound eye, to the anterior optic tubercle (AOTU). The aim of this study is to reveal the connection from the AOTU to the central complex (CX). For this purpose, we investigated the anatomy of large microglomerular synaptic complexes in the medial and lateral bulbs (MBUs/LBUs) of the lateral complex (LX). The synaptic complexes are formed by tubercle-lateral accessory lobe neuron 1 (TuLAL1) neurons of the AOTU and GABAergic tangential neurons of the central body's (CB) lower division (TL neurons). Both TuLAL1 and TL neurons strongly resemble neurons forming these complexes in other insect species. We further investigated the ultrastructure of these synaptic complexes using transmission electron microscopy. We found that single large presynaptic terminals of TuLAL1 neurons enclose many small profiles (SPs) of TL neurons. The synaptic connections between these neurons are established by two types of synapses: divergent dyads and divergent tetrads. Our data support the assumption that these complexes are a highly conserved feature in the insect brain and play an important role in reliable signal transmission within the sky-compass pathway.

Aircraft Fuel Tank Inerting System

DTIC Science & Technology

1983-07-01

The 4950th T~st Wing was to determine If any compass/navigation problems were encoun- tered. Boeing reported that the " Winglet Program" Is encountering... blending TPX, silane, and a peroxide catalyst and reacting the grafted material with water. 2. Extrusioa of the grafted TPX was not successful under a...experiments, particularly in order to evaluate how much of a problem a loss of silane by evaporation would be at the high blending temperatures that had

Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions

PubMed Central

Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

2017-01-01

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d* for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d > d* is satisfied. Using full-sky imaging polarimetry, we measured the d-pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ. From the measured d-patterns of a given sky we determined the proportion P of the sky for which d > d*. We obtained that P is the largest at low solar elevations θ ≈ 0° and under totally or nearly clear skies with cloud coverage ρ = 0%, when the sun's position is already easily determined. If the sun is below the horizon (−5° ≤ θ < 0°) during twilight, P = 76.17 ± 4.18% for dmin∗=23% under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes. PMID:28386426

Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions.

PubMed

Horváth, Gábor; Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

2017-02-01

If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d * for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d  >  d * is satisfied. Using full-sky imaging polarimetry, we measured the d -pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ . From the measured d -patterns of a given sky we determined the proportion P of the sky for which d  >  d *. We obtained that P is the largest at low solar elevations θ  ≈ 0° and under totally or nearly clear skies with cloud coverage ρ  = 0%, when the sun's position is already easily determined. If the sun is below the horizon (-5° ≤  θ  < 0°) during twilight, P  = 76.17 ± 4.18% for [Formula: see text] under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes.

NASA's Chandra Finds That Saturn Reflects X-rays From Sun

NASA Astrophysics Data System (ADS)

2005-05-01

When it comes to mysterious X-rays from Saturn, the ringed planet may act as a mirror, reflecting explosive activity from the sun, according to scientists using NASA's Chandra X-ray Observatory. The findings stem from the first observation of an X-ray flare reflected from Saturn's low-latitudes - the region that correlates to Earth's equator and tropics. Led by Dr. Anil Bhardwaj, a planetary scientist at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., the study revealed that Saturn acts as a diffuse mirror for solar X-rays. Counting photons - particles that carry electromagnetic energy including X-rays - was critical to this discovery. For every few thousand X-ray photons Saturn receives from the sun, it reflects a single X-ray photon back. Previous studies revealed that Jupiter, with a diameter 11 times that of Earth, behaves in a similar fashion. Saturn is about 9.5 times as big as Earth, but is twice as far from Earth as Jupiter. "The bigger the planet and nearer to the Sun, the more solar photons it will intercept - resulting in more reflected X-rays," said Bhardwaj. "These results imply we could use giant planets like Jupiter and Saturn as remote-sensing tools. By reflecting solar activity back to us, they could help us monitor X-ray flaring on portions of the sun facing away from Earth's space satellites." Massive solar explosions called flares often accompany coronal mass ejections, which emit solar material and magnetic field. When directed toward the Earth, these ejections can wreak havoc on communication systems from cell phones to satellites. Even as the research appears to have solved one mystery - the source of Saturn's X-rays, it fueled longstanding questions about magnetic fields. Earth's magnetic field is the reason compasses work, since the field acts like a huge bar magnet, causing the magnetic north pole of a compass to point to the magnetic south pole of the Earth. In addition, migratory birds seem to sense the magnetic field, which allows them to navigate. But other affects of magnetic fields, only recently studied in detail, are obvious only to those living at Earth's high latitudes, or to those observing the Earth from space. Of the three magnetic planets in our solar system that have been studied extensively, Jupiter and Earth emit two general types of X rays -- auroral emissions from polar regions and disk emissions from low latitudes. However, no research to-date - including the recent study using the Chandra Observatory - has observed unambiguous signatures of auroral X-ray emissions on Saturn. "We were surprised to find no clear evidence of auroral X-ray emissions during our observations," said Bhardwaj. "It is interesting to note that even as research solves some mysteries, it confirms there is much more we have to learn. The research appeared in the May 10, 2005 issue of Astrophysical J. Letters, and the team also included Ron Elsner of MSFC; Hunter Waite of the University of Michigan in Ann Arbor; Randy Gladstone of the Southwest Research Institute in San Antonio, Texas; Thomas Cravens of the University of Kansas in Lawrence and Peter Ford from the Massachusetts Institute of Technology in Cambridge. Bhardwaj is working at MSFC on leave from the Space Physics Laboratory of the Vikram Sarabhai Space Centre in India. The Marshall Center manages the Chandra program for NASA's Science Mission Directorate in Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Tracking Electromagnetic Energy With SQUIDs

NASA Technical Reports Server (NTRS)

2005-01-01

A superconducting quantum interference device (SQUID) is a gadget used to measure extremely weak signals, specifically magnetic flux. It can detect subtle changes in energy, up to 100 billion times weaker than the electromagnetic energy required to move a compass needle. SQUIDs are used for a variety of testing procedures where extreme sensitivity is required and where the test instrument need not come into direct contact with the test subject. NASA uses SQUIDs for remote, noncontact sensing in a variety of venues, including monitoring the Earth s magnetic field and tracking brain activity of pilots. Scientists at NASA s Goddard Space Flight Center have been making extensive use of this technology, from astrophysical research, to tracking the navigational paths of bees in flight to determine if they are using internal compasses. These very sensitive measurement devices have a wide variety of uses within NASA and even more uses within the commercial realm.

Angular velocity integration in a fly heading circuit.

PubMed

Turner-Evans, Daniel; Wegener, Stephanie; Rouault, Hervé; Franconville, Romain; Wolff, Tanya; Seelig, Johannes D; Druckmann, Shaul; Jayaraman, Vivek

2017-05-22

Many animals maintain an internal representation of their heading as they move through their surroundings. Such a compass representation was recently discovered in a neural population in the Drosophila melanogaster central complex, a brain region implicated in spatial navigation. Here, we use two-photon calcium imaging and electrophysiology in head-fixed walking flies to identify a different neural population that conjunctively encodes heading and angular velocity, and is excited selectively by turns in either the clockwise or counterclockwise direction. We show how these mirror-symmetric turn responses combine with the neurons' connectivity to the compass neurons to create an elegant mechanism for updating the fly's heading representation when the animal turns in darkness. This mechanism, which employs recurrent loops with an angular shift, bears a resemblance to those proposed in theoretical models for rodent head direction cells. Our results provide a striking example of structure matching function for a broadly relevant computation.

Magnetic Navigation in Sea Turtles: Insights from Secular Variation

NASA Astrophysics Data System (ADS)

Putman, N. F.; Lohmann, K.

2011-12-01

Sea turtles are iconic migrants that posses a sensitive magnetic-sense that guides their long-distance movements in a variety of contexts. In the first few hours after hatching turtles use the magnetic field to maintain an offshore compass heading to reach deeper water, out of the reach of nearshore predators. Young turtles engage in directed swimming in response to regional magnetic fields that exist along their transoceanic migratory path. Older turtles also use magnetic information to relocate foraging sites and islands used for nesting after displacement. Numerous hypotheses have been put forth to explain how magnetic information functions in these movements, however, there is little consensus among animal navigation researchers. A particular vexing issue is how magnetic navigation can function under the constraints of the constant, gradual shifting of the earth's magnetic field (secular variation). Here, I present a framework based on models of recent geomagnetic secular variation to explore several navigational mechanisms proposed for sea turtles. I show that while examination of secular variation likely falsifies some hypothetical navigational strategies, it provides key insights into the selective pressures that could maintain other navigational mechanisms. Moreover, examination of secular variation's influence on the navigational precision in reproductive migrations of sea turtles offers compelling explanations for the population structure along sea turtle nesting beaches as well as spatiotemporal variation in nesting turtle abundance.

Design and implementation of a patient navigation system in rural Nepal: Improving patient experience in resource-constrained settings.

PubMed

Raut, Anant; Thapa, Poshan; Citrin, David; Schwarz, Ryan; Gauchan, Bikash; Bista, Deepak; Tamrakar, Bibhu; Halliday, Scott; Maru, Duncan; Schwarz, Dan

2015-12-01

Patient navigation programs have shown to be effective across multiple settings in guiding patients through the care delivery process. Limited experience and literature exist, however, for such programs in rural and resource-constrained environments. Patients living in such settings frequently have low health literacy and substantially lower social status than their providers. They typically have limited experiences interfacing with formalized healthcare systems, and, when they do, their experience can be unpleasant and confusing. At a district hospital in rural far-western Nepal, we designed and implemented a patient navigation system that aimed to improve patients' subjective care experience. First, we hired and trained a team of patient navigators who we recruited from the local area. Their responsibility is exclusively to demonstrate compassion and to guide patients through their care process. Second, we designed visual cues throughout our hospital complex to assist in navigating patients through the buildings. Third, we incorporated the patient navigators within the management and communications systems of the hospital care team, and established standard operating procedures. We describe here our experiences and challenges in designing and implementing a patient navigator program. Such patient-centered systems may be relevant at other facilities in Nepal and globally where patient health literacy is low, patients come from backgrounds of substantial marginalization and disempowerment, and patient experience with healthcare facilities is limited. Copyright © 2015 Elsevier Inc. All rights reserved.

Anatomical Reconstruction and Functional Imaging Reveal an Ordered Array of Skylight Polarization Detectors in Drosophila

PubMed Central

Bleul, Christiane; Baumann-Klausener, Franziska; Labhart, Thomas; Dickinson, Michael H.

2016-01-01

Many insects exploit skylight polarization as a compass cue for orientation and navigation. In the fruit fly, Drosophila melanogaster, photoreceptors R7 and R8 in the dorsal rim area (DRA) of the compound eye are specialized to detect the electric vector (e-vector) of linearly polarized light. These photoreceptors are arranged in stacked pairs with identical fields of view and spectral sensitivities, but mutually orthogonal microvillar orientations. As in larger flies, we found that the microvillar orientation of the distal photoreceptor R7 changes in a fan-like fashion along the DRA. This anatomical arrangement suggests that the DRA constitutes a detector for skylight polarization, in which different e-vectors maximally excite different positions in the array. To test our hypothesis, we measured responses to polarized light of varying e-vector angles in the terminals of R7/8 cells using genetically encoded calcium indicators. Our data confirm a progression of preferred e-vector angles from anterior to posterior in the DRA, and a strict orthogonality between the e-vector preferences of paired R7/8 cells. We observed decreased activity in photoreceptors in response to flashes of light polarized orthogonally to their preferred e-vector angle, suggesting reciprocal inhibition between photoreceptors in the same medullar column, which may serve to increase polarization contrast. Together, our results indicate that the polarization-vision system relies on a spatial map of preferred e-vector angles at the earliest stage of sensory processing. SIGNIFICANCE STATEMENT The fly's visual system is an influential model system for studying neural computation, and much is known about its anatomy, physiology, and development. The circuits underlying motion processing have received the most attention, but researchers are increasingly investigating other functions, such as color perception and object recognition. In this work, we investigate the early neural processing of a somewhat exotic sense, called polarization vision. Because skylight is polarized in an orientation that is rigidly determined by the position of the sun, this cue provides compass information. Behavioral experiments have shown that many species use the polarization pattern in the sky to direct locomotion. Here we describe the input stage of the fly's polarization-vision system. PMID:27170135

How the clear-sky angle of polarization pattern continues underneath clouds: full-sky measurements and implications for animal orientation.

PubMed

Pomozi, I; Horváth, G; Wehner, R

2001-09-01

One of the biologically most important parameters of the cloudy sky is the proportion P of the celestial polarization pattern available for use in animal navigation. We evaluated this parameter by measuring the polarization patterns of clear and cloudy skies using 180 degrees (full-sky) imaging polarimetry in the red (650 nm), green (550 nm) and blue (450 nm) ranges of the spectrum under clear and partly cloudy conditions. The resulting data were compared with the corresponding celestial polarization patterns calculated using the single-scattering Rayleigh model. We show convincingly that the pattern of the angle of polarization (e-vectors) in a clear sky continues underneath clouds if regions of the clouds and parts of the airspace between the clouds and the earth surface (being shady at the position of the observer) are directly lit by the sun. The scattering and polarization of direct sunlight on the cloud particles and in the air columns underneath the clouds result in the same e-vector pattern as that present in clear sky. This phenomenon can be exploited for animal navigation if the degree of polarization is higher than the perceptual threshold of the visual system, because the angle rather than the degree of polarization is the most important optical cue used in the polarization compass. Hence, the clouds reduce the extent of sky polarization pattern that is useful for animal orientation much less than has hitherto been assumed. We further demonstrate quantitatively that the shorter the wavelength, the greater the proportion of celestial polarization that can be used by animals under cloudy-sky conditions. As has already been suggested by others, this phenomenon may solve the ultraviolet paradox of polarization vision in insects such as hymenopterans and dipterans. The present study extends previous findings by using the technique of 180 degrees imaging polarimetry to measure and analyse celestial polarization patterns.

Biophysical processes leading to the ingress of temperate fish larvae into estuarine nursery areas: A review

NASA Astrophysics Data System (ADS)

Teodósio, Maria Alexandra; Paris, Claire B.; Wolanski, Eric; Morais, Pedro

2016-12-01

A series of complementary hypotheses have been proposed to explain the recruitment of marine and temperate pelagic fish larvae originated from pelagic eggs in coastal environments. In this review, we propose a new and complementary hypothesis describing the biophysical processes intervening in the recruitment of temperate fish larvae into estuaries. This new hypothesis, the Sense Acuity And Behavioral (SAAB) hypothesis, recognizes that recruitment is unlikely if the larvae drift passively with the water currents, and that successful recruitment requires the sense acuity of temperate fish larvae and their behavioral response to the estuarine cues present in coastal areas. We propose that temperate fish larvae use a hierarchy of sensory cues (odor, sound, visual and geomagnetic cues) to detect estuarine nursery areas and to aid during navigation towards these areas. The sensorial acuity increases along ontogeny, which coincides with increased swimming capabilities. The swimming strategies of post-flexion larvae differ from offshore areas to the tidal zone. In offshore areas, innate behavior might lead larvae towards the coast guided by a sun compass or by the earth's geomagnetic field. In areas under limited influence of estuarine plumes (either in energetic nearshore areas or offshore), post-flexion larvae display a searching swimming behavior for estuarine disconnected patches (infotaxis strategy). After finding an estuarine plume, larvae may swim along the increasing cue concentration to ingress into the estuary. Here, larvae exhibit a rheotaxis behavior and avoid displacement by longshore currents by keeping bearing during navigation. When larvae reach the vicinity of an estuary, merging diel rhythms with feeding and predator avoidance strategies with tidally induced movements is essential to increase their chances of estuarine ingress. A fish larva recruitment model developed for the Ria Formosa lagoon supports the general framework of the SAAB hypothesis. In this model, the ingress of virtual Sparidae temperate larvae into this nursery area increases from 1.5% to 32.1% when directional swimming guided by estuarine cues is included as a forcing parameter.

My Changed Body: Background, development and acceptability of a self-compassion based writing activity for female survivors of breast cancer.

PubMed

Przezdziecki, Astrid; Alcorso, Jessica; Sherman, Kerry A

2016-05-01

To assess consumer and health professional user acceptability of a web-based self-compassion writing activity to minimize psychological distress related to the negative impact of breast cancer on body image. "My Changed Body" is a web-based writing activity that combines expressive writing with a self-compassionate approach that focuses on cancer-related adverse body image alterations. Breast cancer survivors (n=15) and health professionals (n=20) provided feedback via a survey regarding the appearance, organization and content of the website and writing activity. Both breast cancer survivors and health professionals rated the website highly in terms of design, layout and content. Participants commented positively on the website's clear wording, appealing design and ease of navigation. Suggestions for improving the website included simplifying the instructions for the writing activity and allowing participants' writing to be saved. Results from both breast cancer survivors and health professionals suggest a moderate to high level of user acceptability and positive ratings for the overall impression of the website. Self-compassion based writing interventions can be translated to a web-based self-administered activity for body image difficulties after breast cancer treatment in a format that is acceptable to consumers and health professionals. Copyright © 2016. Published by Elsevier Ireland Ltd.

The polarization compass dominates over idiothetic cues in path integration of desert ants.

PubMed

Lebhardt, Fleur; Koch, Julja; Ronacher, Bernhard

2012-02-01

Desert ants, Cataglyphis, use the sky's pattern of polarized light as a compass reference for navigation. However, they do not fully exploit the complexity of this pattern, rather - as proposed previously - they assess their walking direction by means of an approximate solution based on a simplified internal template. Approximate rules are error-prone. We therefore asked whether the ants use additional cues to improve the accuracy of directional decisions, and focused on 'idiothetic' cues, i.e. cues based on information from proprioceptors. We trained ants in a channel system that was covered with a polarization filter, providing only a single e-vector direction as a directional 'celestial' cue. Then we observed their homebound runs on a test field, allowing full view of the sky. In crucial experiments, the ants were exposed to a cue conflict, in which sky compass and idiothetic information disagreed, by training them in a straight channel that provided a change in e-vector direction. The results indicated that the polarization information completely dominates over idiothetic cues. Two path segments with different e-vector orientations are combined linearly to a summed home vector. Our data provide additional evidence that Cataglyphis uses a simplified internal template to derive directional information from the sky's polarization pattern.

COMPASS Final Report: Lunar Relay Satellite (LRS)

NASA Technical Reports Server (NTRS)

Oleson, Steven R.; McGuire, Melissa L.

2012-01-01

The Lunar Relay Satellite (LRS) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session was tasked to design a satellite to orbit in an elliptical lunar polar orbit to provide relay communications between lunar South Pole assets and the Earth. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The LRS is a half-TDRSS sized box spacecraft, which provides communications and navigation relay between lunar outposts (via Lunar Communications Terminals (LCT)) or Sortie parties (with user radios) and large ground antennas on Earth. The LRS consists of a spacecraft containing all the communications and avionics equipment designed by NASA Jet Propulsion Laboratory s (JPL) Team X to perform the relay between lunar-based assets and the Earth. The satellite design is a standard box truss spacecraft design with a thermal control system, 1.7 m solar arrays for 1 kWe power, a 1 m diameter Ka/S band dish which provides relay communications with the LCT, and a Q-band dish for communications to/from the Earth based assets. While JPL's Team X and Goddard Space Flight Center s (GSFC) I M Design Center (IMDC) have completed two other LRS designs, this NASA Glenn Research Center (GRC) COMPASS LRS design sits between them in terms of physical size and capabilities.

An experimental approach in revisiting the magnetic orientation of cattle.

PubMed

Weijers, Debby; Hemerik, Lia; Heitkönig, Ignas M A

2018-01-01

In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations-excluding the hottest part of the day-of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals.

Global positioning method based on polarized light compass system

NASA Astrophysics Data System (ADS)

Liu, Jun; Yang, Jiangtao; Wang, Yubo; Tang, Jun; Shen, Chong

2018-05-01

This paper presents a global positioning method based on a polarized light compass system. A main limitation of polarization positioning is the environment such as weak and locally destroyed polarization environments, and the solution to the positioning problem is given in this paper which is polarization image de-noising and segmentation. Therefore, the pulse coupled neural network is employed for enhancing positioning performance. The prominent advantages of the present positioning technique are as follows: (i) compared to the existing position method based on polarized light, better sun tracking accuracy can be achieved and (ii) the robustness and accuracy of positioning under weak and locally destroyed polarization environments, such as cloudy or building shielding, are improved significantly. Finally, some field experiments are given to demonstrate the effectiveness and applicability of the proposed global positioning technique. The experiments have shown that our proposed method outperforms the conventional polarization positioning method, the real time longitude and latitude with accuracy up to 0.0461° and 0.0911°, respectively.

Polarization-Sensitive Interneurons in the Optic Lobe of the Desert Ant Cataglyphis bicolor

NASA Astrophysics Data System (ADS)

Labhart, Thomas

Desert ants, Cataglyphis bicolor (Hymenoptera), navigate by using compass information provided by skylight polarization. In this study, electrophysiological recordings were made from polarization-sensitive interneurons (POL-neurons) in the optic lobe of Cataglyphis. The POL-neurons exhibit a characteristic polarization opponency. They receive monochromatic input from the UV receptors of the specialized dorsal rim area of the compound eye. Both polarization opponency and monochromacy are features also found in the POL-neurons of crickets (Orthoptera).

Capturing the Sun: A Roadmap for Navigating Data-Access Challenges and Auto-Populating Solar Home Sales Listings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stukel, Laura; Hoen, Ben; Adomatis, Sandra

Capturing the Sun: A Roadmap for Navigating Data-Access Challenges and Auto-Populating Solar Home Sales Listings supports a vision of solar photovoltaic (PV) advocates and real estate advocates evolving together to make information about solar homes more accessible to home buyers and sellers and to simplify the process when these homes are resold. The Roadmap is based on a concept in the real estate industry known as automatic population of fields. Auto-population (also called auto-pop in the industry) is the technology that allows data aggregated by an outside industry to be matched automatically with home sale listings in a multiple listingmore » service (MLS).« less

True navigation and magnetic maps in spiny lobsters.

PubMed

Boles, Larry C; Lohmann, Kenneth J

2003-01-02

Animals are capable of true navigation if, after displacement to a location where they have never been, they can determine their position relative to a goal without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey. So far, only a few animals, all vertebrates, have been shown to possess true navigation. Those few invertebrates that have been carefully studied return to target areas using path integration, landmark recognition, compass orientation and other mechanisms that cannot compensate for displacements into unfamiliar territory. Here we report, however, that the spiny lobster Panulirus argus oriented reliably towards a capture site when displaced 12-37 km to unfamiliar locations, even when deprived of all known orientation cues en route. Little is known about how lobsters and other animals determine position during true navigation. To test the hypothesis that lobsters derive positional information from the Earth's magnetic field, lobsters were exposed to fields replicating those that exist at specific locations in their environment. Lobsters tested in a field north of the capture site oriented themselves southwards, whereas those tested in a field south of the capture site oriented themselves northwards. These results imply that true navigation in spiny lobsters, and perhaps in other animals, is based on a magnetic map sense.

New experiments on the effect of clock shifts on homing in pigeons

NASA Technical Reports Server (NTRS)

Schmidt-Koenig, K.

1972-01-01

The effect of clock shifts as an experimental tool for predictably interfering with the homing ability of birds is discussed. Clock shifts introduce specific errors in the birds' sun azimuth compass, resulting in corresponding errors during initial orientation and possibly during orientation enroute. The effects of 6 hour and 12 hour clock shifts resulted in a 90 degree deviation and a 180 degree deviation from the initial orientation, respectively. The method for conducting the clock shift experiments and results obtained from previous experiments are described.

[Birds' sense of direction].

PubMed

Hohtola, Esa

2016-01-01

Birds utilize several distinct sensory systems in a flexible manner in their navigation. When navigating with the help of landmarks, location of the sun and stars, or polarization image of the dome of the sky, they resort to vision. The significance of olfaction in long-range navigation has been under debate, even though its significance in local orientation is well documented. The hearing in birds extends to the infrasound region. It has been assumed that they are able to hear the infrasounds generated in the mountains and seaside and navigate by using them. Of the senses of birds, the most exotic one is the ability to sense magnetic fields of the earth.

Diver-based integrated navigation/sonar sensor

NASA Astrophysics Data System (ADS)

Lent, Keith H.

1999-07-01

Two diver based systems, the Small Object Locating Sonar (SOLS) and the Integrated Navigation and Sonar Sensor (INSS) have been developed at Applied Research Laboratories, the University of Texas at Austin (ARL:UT). They are small and easy to use systems that allow a diver to: detect, classify, and identify underwater objects; render large sector visual images; and track, map and reacquire diver location, diver path, and target locations. The INSS hardware consists of a unique, simple, single beam high resolution sonar, an acoustic navigation systems, an electronic depth gauge, compass, and GPS and RF interfaces, all integrated with a standard 486 based PC. These diver sonars have been evaluated by the very shallow water mine countermeasure detachment since spring 1997. Results are very positive, showing significantly greater capabilities than current diver held systems. For example, the detection ranges are increased over existing systems, and the system allows the divers to classify mines at a significant stand off range. As a result, the INSS design has been chosen for acquisition as the next generation diver navigation and sonar system. The EDMs for this system will be designed and built by ARL:UT during 1998 and 1999 with production planned in 2000.

Auxiliary subprograms for calculating the navigational parameters of artificial Earth satellites. FORTRAN IV

NASA Technical Reports Server (NTRS)

Prokhorenko, V. I.

1981-01-01

Subprograms for transforming coordinates and time, for determining the position of the Moon and Sun, and for calculating the atmosphere and disturbances, which are specified by anomalies of the Earth's gravitational field are described. The subprograms are written in FORTRAN IV and form a major part of the package of applied programs for calculating the navigational parameters of artificial Earth satellites.

Angular velocity integration in a fly heading circuit

PubMed Central

Turner-Evans, Daniel; Wegener, Stephanie; Rouault, Hervé; Franconville, Romain; Wolff, Tanya; Seelig, Johannes D; Druckmann, Shaul; Jayaraman, Vivek

2017-01-01

Many animals maintain an internal representation of their heading as they move through their surroundings. Such a compass representation was recently discovered in a neural population in the Drosophila melanogaster central complex, a brain region implicated in spatial navigation. Here, we use two-photon calcium imaging and electrophysiology in head-fixed walking flies to identify a different neural population that conjunctively encodes heading and angular velocity, and is excited selectively by turns in either the clockwise or counterclockwise direction. We show how these mirror-symmetric turn responses combine with the neurons’ connectivity to the compass neurons to create an elegant mechanism for updating the fly’s heading representation when the animal turns in darkness. This mechanism, which employs recurrent loops with an angular shift, bears a resemblance to those proposed in theoretical models for rodent head direction cells. Our results provide a striking example of structure matching function for a broadly relevant computation. DOI: http://dx.doi.org/10.7554/eLife.23496.001 PMID:28530551

Infrasound and the avian navigational map.

PubMed

Hagstrum, J T

2000-04-01

Birds can navigate accurately over hundreds to thousands of kilometres, and this ability of homing pigeons is the basis for a worldwide sport. Compass senses orient avian flight, but how birds determine their location in order to select the correct homeward bearing (map sense) remains a mystery. Also mysterious are rare disruptions of pigeon races in which most birds are substantially delayed and large numbers are lost. Here, it is shown that in four recent pigeon races in Europe and the northeastern USA the birds encountered infrasonic (low-frequency acoustic) shock waves from the Concorde supersonic transport. An acoustic avian map is proposed that consists of infrasonic cues radiated from steep-sided topographic features; the source of these signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting these infrasonic map cues can explain perplexing experimental results from pigeon releases.

Measuring Magnetic Declination With Compass, GPS and Virtual Globes

NASA Astrophysics Data System (ADS)

O'Brien, W. P.

2006-12-01

Using virtual globe (VG) imagery to determine geographic bearing and a compass to determine magnetic bearing yielded acceptable experimental magnetic declination values for large linear physical features at 13 sites in the western continental United States. The geographic bearing of each feature was determined from measurements involving the latitude/longitude coordinate system associated with the VG image (from World Wind or Google Earth). The corresponding magnetic bearing was measured on the ground at the feature with a hand-bearing compass calibrated in 1-degree subdivisions. A sequence of GPS trackpoints, recorded while traveling along the feature either in an automobile or on foot, unambiguously identified the pertinent portion of the feature (a straight segment of a road, for example) when plotted on the VG image. For each physical feature located on a VG image, its geographic bearing was determined directly using on-screen measurement tools available with the VG program or by hand using ruler/protractor methods with printed copies of the VG image. An independent (no use of VG) geographic bearing was also extracted from the slope of a straight-line fit to a latitude/longitude plot of each feature's GPS coordinates, a value that was the same (to within the inherent uncertainty of the data) as the VG-determined bearing, thus validating this procedure for finding geographic bearings. Differences between the VG bearings and the magnetic bearings yielded experimental magnetic declination values within one degree (8 within 0.5 degree) of expected values. From the point of view of physics and geophysics pedagogy, this project affords students a simple magnetism/geodesy field experiment requiring only a good compass and a GPS receiver with memory and a data port. The novel and straightforward data analysis with VG software yields reliable experimental values for an important abstract geophysical quantity, magnetic declination. Just as the compass has long provided easy access to Magnetic North, the coordinate systems inherent in recently-developed VG and GPS satellite technologies now provide easy access (i.e., no astronomical measurements involving Polaris or the Sun) to Geographic North for this and future applications.

The connection between landscapes and the solar ephemeris in honeybees.

PubMed

Towne, William F; Moscrip, Heather

2008-12-01

Honeybees connect the sun's daily pattern of azimuthal movement to some aspect of the landscape around their nests. In the present study, we ask what aspect of the landscape is used in this context--the entire landscape panorama or only sectors seen along familiar flight routes. Previous studies of the solar ephemeris memory in bees have generally used bees that had experience flying a specific route, usually along a treeline, to a feeder. When such bees were moved to a differently oriented treeline on overcast days, the bees oriented their communicative dances as if they were still at the first treeline, based on a memory of the sun's course in relation to some aspect of the site, possibly the familiar route along the treeline or possibly the entire landscape or skyline panorama. Our results show that bees lacking specific flight-route training can nonetheless recall the sun's compass bearing relative to novel flight routes in their natal landscape. Specifically, we moved a hive from one landscape to a differently oriented twin landscape, and only after transplantation under overcast skies did we move a feeder away from the hive. These bees nonetheless danced accurately by memory of the sun's course in relation to their natal landscape. The bees' knowledge of the relationship between the sun and landscape, therefore, is not limited to familiar flight routes and so may encompass, at least functionally, the entire panorama. Further evidence suggests that the skyline in particular may be the bees' preferred reference in this context.

An experimental approach in revisiting the magnetic orientation of cattle

PubMed Central

Weijers, Debby; Hemerik, Lia; Heitkönig, Ignas M. A.

2018-01-01

In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations—excluding the hottest part of the day—of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals. PMID:29641517

Lucy: Navigating a Jupiter Trojan Tour

NASA Technical Reports Server (NTRS)

Stanbridge, Dale; Williams, Ken; Williams, Bobby; Jackman, Coralie; Weaver, Hal; Berry, Kevin; Sutter, Brian; Englander, Jacob

2017-01-01

In January 2017, NASA selected the Lucy mission to explore six Jupiter Trojan asteroids. These six bodies, remnants of the primordial material that formed the outer planets, were captured in the Sun-Jupiter L4 and L5 Lagrangian regions early in the solar system formation. These particular bodies were chosen because of their diverse spectral properties and the chance to observe up close for the first time two orbiting approximately equal mass binaries, Patroclus and Menoetius. KinetX, Inc. is the primary navigation supplier for the Lucy mission. This paper describes preliminary navigation analyses of the approach phase for each Trojan encounter.

Optimal multiguidance integration in insect navigation.

PubMed

Hoinville, Thierry; Wehner, Rüdiger

2018-03-13

In the last decades, desert ants have become model organisms for the study of insect navigation. In finding their way, they use two major navigational routines: path integration using a celestial compass and landmark guidance based on sets of panoramic views of the terrestrial environment. It has been claimed that this information would enable the insect to acquire and use a centralized cognitive map of its foraging terrain. Here, we present a decentralized architecture, in which the concurrently operating path integration and landmark guidance routines contribute optimally to the directions to be steered, with "optimal" meaning maximizing the certainty (reliability) of the combined information. At any one time during its journey, the animal computes a path integration (global) vector and landmark guidance (local) vector, in which the length of each vector is proportional to the certainty of the individual estimates. Hence, these vectors represent the limited knowledge that the navigator has at any one place about the direction of the goal. The sum of the global and local vectors indicates the navigator's optimal directional estimate. Wherever applied, this decentralized model architecture is sufficient to simulate the results of quite a number of diverse cue-conflict experiments, which have recently been performed in various behavioral contexts by different authors in both desert ants and honeybees. They include even those experiments that have deliberately been designed by former authors to strengthen the evidence for a metric cognitive map in bees.

Mapping the navigational knowledge of individually foraging ants, Myrmecia croslandi

PubMed Central

Narendra, Ajay; Gourmaud, Sarah; Zeil, Jochen

2013-01-01

Ants are efficient navigators, guided by path integration and visual landmarks. Path integration is the primary strategy in landmark-poor habitats, but landmarks are readily used when available. The landmark panorama provides reliable information about heading direction, routes and specific location. Visual memories for guidance are often acquired along routes or near to significant places. Over what area can such locally acquired memories provide information for reaching a place? This question is unusually approachable in the solitary foraging Australian jack jumper ant, since individual foragers typically travel to one or two nest-specific foraging trees. We find that within 10 m from the nest, ants both with and without home vector information available from path integration return directly to the nest from all compass directions, after briefly scanning the panorama. By reconstructing panoramic views within the successful homing range, we show that in the open woodland habitat of these ants, snapshot memories acquired close to the nest provide sufficient navigational information to determine nest-directed heading direction over a surprisingly large area, including areas that animals may have not visited previously. PMID:23804615

Heavenly Bodies and Phenomena in Petroglyphs

NASA Astrophysics Data System (ADS)

Tokhatyan, Karen

2016-12-01

In Armenian culture are amply reflected realities connected with Universe. Their figurative expressions are also petroglyphs in which there are representations of solar signs, swastika, Moon crescend, planets, stars, star groups, constellations, Milky Way, Earth. Among heavenly and atmospheric phenomena are: eclipce, meteor, comet, ligthning, cloud, rain and rainbow. There are many products of scientific thinking: stellar maps, calendars, compasses, astronomical records, Zodiac signs and ideograms. Thousands of the Armenian petroglyphs that were created millennia ago by an indigenous ethnos - Armenians, point to the significant place of celestial bodies and luminaries, especially the Sun, stars, and stellar constellations in our ancestors' cosmological perceptions.

Bioinspired optical sensors for unmanned aerial systems

NASA Astrophysics Data System (ADS)

Chahl, Javaan; Rosser, Kent; Mizutani, Akiko

2011-04-01

Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.

Quantum coherence and entanglement in the avian compass.

PubMed

Pauls, James A; Zhang, Yiteng; Berman, Gennady P; Kais, Sabre

2013-06-01

The radical-pair mechanism is one of two distinct mechanisms used to explain the navigation of birds in geomagnetic fields, however little research has been done to explore the role of quantum entanglement in this mechanism. In this paper we study the lifetime of radical-pair entanglement corresponding to the magnitude and direction of magnetic fields to show that the entanglement lasts long enough in birds to be used for navigation. We also find that the birds appear to not be able to orient themselves directly based on radical-pair entanglement due to a lack of orientation sensitivity of the entanglement in the geomagnetic field. To explore the entanglement mechanism further, we propose a model in which the hyperfine interactions are replaced by local magnetic fields of similar strength. The entanglement of the radical pair in this model lasts longer and displays an angular sensitivity in weak magnetic fields, both of which are not present in previous models.

Contribution of BeiDou satellite system for long baseline GNSS measurement in Indonesia

NASA Astrophysics Data System (ADS)

Gumilar, I.; Bramanto, B.; Kuntjoro, W.; Abidin, H. Z.; Trihantoro, N. F.

2018-05-01

The demand for more precise positioning method using GNSS (Global Navigation Satellite System) in Indonesia continue to rise. The accuracy of GNSS positioning depends on the length of baseline and the distribution of observed satellites. BeiDou Navigation Satellite System (BDS) is a positioning system owned by China that operating in Asia-Pacific region, including Indonesia. This research aims to find out the contribution of BDS in increasing the accuracy of long baseline static positioning in Indonesia. The contributions are assessed by comparing the accuracy of measurement using only GPS (Global Positioning System) and measurement using the combination of GPS and BDS. The data used is 5 days of GPS and BDS measurement data for baseline with 120 km in length. The software used is open-source RTKLIB and commercial software Compass Solution. This research will explain in detail the contribution of BDS to the accuracy of position in long baseline static GNSS measurement.

Parachute Testing for the NASA X-38 Crew Return Vehicle

NASA Technical Reports Server (NTRS)

Stein, Jenny M.

2005-01-01

NASA's X-38 program was an in-house technology demonstration program to develop a Crew Return Vehicle (CRV) for the International Space Station capable of returning seven crewmembers to Earth when the Space Shuttle was not present at the station. The program, managed out of NASA's Johnson Space Center, was started in 1995 and was cancelled in 2003. Eight flights with a prototype atmospheric vehicle were successfully flown at Edwards Air Force Base, demonstrating the feasibility of a parachute landing system for spacecraft. The intensive testing conducted by the program included testing of large ram-air parafoils. The flight test techniques, instrumentation, and simulation models developed during the parachute test program culminated in the successful demonstration of a guided parafoil system to land a 25,000 Ib spacecraft. The test program utilized parafoils of sizes ranging from 750 to 7500 p. The guidance, navigation, and control system (GN&C) consisted of winches, laser or radar altimeter, global positioning system (GPS), magnetic compass, barometric altimeter, flight computer, and modems for uplink commands and downlink data. The winches were used to steer the parafoil and to perform the dynamic flare maneuver for a soft landing. The laser or radar altimeter was used to initiate the flare. In the event of a GPS failure, the software navigated by dead reckoning using the compass and barometric altimeter data. The GN&C test beds included platforms dropped from cargo aircraft, atmospheric vehicles released from a 8-52, and a Buckeye powered parachute. This paper will describe the test program and significant results.

Seamless positioning and navigation by using geo-referenced images and multi-sensor data.

PubMed

Li, Xun; Wang, Jinling; Li, Tao

2013-07-12

Ubiquitous positioning is considered to be a highly demanding application for today's Location-Based Services (LBS). While satellite-based navigation has achieved great advances in the past few decades, positioning and navigation in indoor scenarios and deep urban areas has remained a challenging topic of substantial research interest. Various strategies have been adopted to fill this gap, within which vision-based methods have attracted growing attention due to the widespread use of cameras on mobile devices. However, current vision-based methods using image processing have yet to revealed their full potential for navigation applications and are insufficient in many aspects. Therefore in this paper, we present a hybrid image-based positioning system that is intended to provide seamless position solution in six degrees of freedom (6DoF) for location-based services in both outdoor and indoor environments. It mainly uses visual sensor input to match with geo-referenced images for image-based positioning resolution, and also takes advantage of multiple onboard sensors, including the built-in GPS receiver and digital compass to assist visual methods. Experiments demonstrate that such a system can greatly improve the position accuracy for areas where the GPS signal is negatively affected (such as in urban canyons), and it also provides excellent position accuracy for indoor environments.

Seamless Positioning and Navigation by Using Geo-Referenced Images and Multi-Sensor Data

PubMed Central

Li, Xun; Wang, Jinling; Li, Tao

2013-01-01

Ubiquitous positioning is considered to be a highly demanding application for today's Location-Based Services (LBS). While satellite-based navigation has achieved great advances in the past few decades, positioning and navigation in indoor scenarios and deep urban areas has remained a challenging topic of substantial research interest. Various strategies have been adopted to fill this gap, within which vision-based methods have attracted growing attention due to the widespread use of cameras on mobile devices. However, current vision-based methods using image processing have yet to revealed their full potential for navigation applications and are insufficient in many aspects. Therefore in this paper, we present a hybrid image-based positioning system that is intended to provide seamless position solution in six degrees of freedom (6DoF) for location-based services in both outdoor and indoor environments. It mainly uses visual sensor input to match with geo-referenced images for image-based positioning resolution, and also takes advantage of multiple onboard sensors, including the built-in GPS receiver and digital compass to assist visual methods. Experiments demonstrate that such a system can greatly improve the position accuracy for areas where the GPS signal is negatively affected (such as in urban canyons), and it also provides excellent position accuracy for indoor environments. PMID:23857267

Anatomical Reconstruction and Functional Imaging Reveal an Ordered Array of Skylight Polarization Detectors in Drosophila.

PubMed

Weir, Peter T; Henze, Miriam J; Bleul, Christiane; Baumann-Klausener, Franziska; Labhart, Thomas; Dickinson, Michael H

2016-05-11

Many insects exploit skylight polarization as a compass cue for orientation and navigation. In the fruit fly, Drosophila melanogaster, photoreceptors R7 and R8 in the dorsal rim area (DRA) of the compound eye are specialized to detect the electric vector (e-vector) of linearly polarized light. These photoreceptors are arranged in stacked pairs with identical fields of view and spectral sensitivities, but mutually orthogonal microvillar orientations. As in larger flies, we found that the microvillar orientation of the distal photoreceptor R7 changes in a fan-like fashion along the DRA. This anatomical arrangement suggests that the DRA constitutes a detector for skylight polarization, in which different e-vectors maximally excite different positions in the array. To test our hypothesis, we measured responses to polarized light of varying e-vector angles in the terminals of R7/8 cells using genetically encoded calcium indicators. Our data confirm a progression of preferred e-vector angles from anterior to posterior in the DRA, and a strict orthogonality between the e-vector preferences of paired R7/8 cells. We observed decreased activity in photoreceptors in response to flashes of light polarized orthogonally to their preferred e-vector angle, suggesting reciprocal inhibition between photoreceptors in the same medullar column, which may serve to increase polarization contrast. Together, our results indicate that the polarization-vision system relies on a spatial map of preferred e-vector angles at the earliest stage of sensory processing. The fly's visual system is an influential model system for studying neural computation, and much is known about its anatomy, physiology, and development. The circuits underlying motion processing have received the most attention, but researchers are increasingly investigating other functions, such as color perception and object recognition. In this work, we investigate the early neural processing of a somewhat exotic sense, called polarization vision. Because skylight is polarized in an orientation that is rigidly determined by the position of the sun, this cue provides compass information. Behavioral experiments have shown that many species use the polarization pattern in the sky to direct locomotion. Here we describe the input stage of the fly's polarization-vision system. Copyright © 2016 the authors 0270-6474/16/365397-08$15.00/0.

Adjustment errors of sunstones in the first step of sky-polarimetric Viking navigation: studies with dichroic cordierite/ tourmaline and birefringent calcite crystals.

PubMed

Száz, Dénes; Farkas, Alexandra; Blahó, Miklós; Barta, András; Egri, Ádám; Kretzer, Balázs; Hegedüs, Tibor; Jäger, Zoltán; Horváth, Gábor

2016-01-01

According to an old but still unproven theory, Viking navigators analysed the skylight polarization with dichroic cordierite or tourmaline, or birefringent calcite sunstones in cloudy/foggy weather. Combining these sunstones with their sun-dial, they could determine the position of the occluded sun, from which the geographical northern direction could be guessed. In psychophysical laboratory experiments, we studied the accuracy of the first step of this sky-polarimetric Viking navigation. We measured the adjustment error e of rotatable cordierite, tourmaline and calcite crystals when the task was to determine the direction of polarization of white light as a function of the degree of linear polarization p. From the obtained error functions e(p), the thresholds p* above which the first step can still function (i.e. when the intensity change seen through the rotating analyser can be sensed) were derived. Cordierite is about twice as reliable as tourmaline. Calcite sunstones have smaller adjustment errors if the navigator looks for that orientation of the crystal where the intensity difference between the two spots seen in the crystal is maximal, rather than minimal. For higher p (greater than p crit) of incident light, the adjustment errors of calcite are larger than those of the dichroic cordierite (p crit=20%) and tourmaline (p crit=45%), while for lower p (less than p crit) calcite usually has lower adjustment errors than dichroic sunstones. We showed that real calcite crystals are not as ideal sunstones as it was believed earlier, because they usually contain scratches, impurities and crystal defects which increase considerably their adjustment errors. Thus, cordierite and tourmaline can also be at least as good sunstones as calcite. Using the psychophysical e(p) functions and the patterns of the degree of skylight polarization measured by full-sky imaging polarimetry, we computed how accurately the northern direction can be determined with the use of the Viking sun-dial under 10 different sky conditions at 61° latitude, which was one of the main Viking sailing routes. According to our expermiments, under clear skies, using calcite or cordierite or tourmaline sunstones, Viking sailors could navigate with net orientation errors [Formula: see text]. Under overcast conditions, their net navigation error depends on the sunstone type: [Formula: see text], [Formula: see text] and [Formula: see text].

Autonomous navigation accuracy using simulated horizon sensor and sun sensor observations

NASA Technical Reports Server (NTRS)

Pease, G. E.; Hendrickson, H. T.

1980-01-01

A relatively simple autonomous system which would use horizon crossing indicators, a sun sensor, a quartz oscillator, and a microprogrammed computer is discussed. The sensor combination is required only to effectively measure the angle between the centers of the Earth and the Sun. Simulations for a particular orbit indicate that 2 km r.m.s. orbit determination uncertainties may be expected from a system with 0.06 deg measurement uncertainty. A key finding is that knowledge of the satellite orbit plane orientation can be maintained to this level because of the annual motion of the Sun and the predictable effects of Earth oblateness. The basic system described can be updated periodically by transits of the Moon through the IR horizon crossing indicator fields of view.

Results of the Magnetometer Navigation (MAGNAV)lnflight Experiment

NASA Technical Reports Server (NTRS)

Thienel, Julie K.; Harman, Richard R.; Bar-Itzhack, Itzhack Y.; Lambertson, Mike

2004-01-01

The Magnetometer Navigation (MAGNAV) algorithm is currently running as a flight experiment as part of the Wide Field Infrared Explorer (WIRE) Post-Science Engineering Testbed. Initialization of MAGNAV occurred on September 4, 2003. MAGNAV is designed to autonomously estimate the spacecraft orbit, attitude, and rate using magnetometer and sun sensor data. Since the Earth's magnetic field is a function of time and position, and since time is known quite precisely, the differences between the computed magnetic field and measured magnetic field components, as measured by the magnetometer throughout the entire spacecraft orbit, are a function of the spacecraft trajectory and attitude errors. Therefore, these errors are used to estimate both trajectory and attitude. In addition, the time rate of change of the magnetic field vector is used to estimate the spacecraft rotation rate. The estimation of the attitude and trajectory is augmented with the rate estimation into an Extended Kalman filter blended with a pseudo-linear Kalman filter. Sun sensor data is also used to improve the accuracy and observability of the attitude and rate estimates. This test serves to validate MAGNAV as a single low cost navigation system which utilizes reliable, flight qualified sensors. MAGNAV is intended as a backup algorithm, an initialization algorithm, or possibly a prime navigation algorithm for a mission with coarse requirements. Results from the first six months of operation are presented.

Design and analysis of miniature tri-axial fluxgate magnetometer

NASA Astrophysics Data System (ADS)

Zhi, Menghui; Tang, Liang; Qiao, Donghai

2017-02-01

The detection technology of weak magnetic field is widely used in Earth resource survey and geomagnetic navigation. Useful magnetic field information can be obtained by processing and analyzing the measurement data from magnetic sensors. A miniature tri-axial fluxgate magnetometer is proposed in this paper. This miniature tri-axial fluxgate magnetometer with ring-core structure has a dynamic range of the Earth’s field ±65,000 nT, resolution of several nT. It has three independent parts placed in three perpendicular planes for measuring three orthogonal magnetic field components, respectively. A field-programmable gate array (FPGA) is used to generate stimulation signal, analog-to-digital (A/D) convertor control signal, and feedback digital-to-analog (D/A) control signal. Design and analysis details are given to improve the dynamic range, sensitivity, resolution, and linearity. Our prototype was measured and compared with a commercial standard Magson fluxgate magnetometer as a reference. The results show that our miniature fluxgate magnetometer can follow the Magson’s change trend well. When used as a magnetic compass, our prototype only has ± 0.3∘ deviation compared with standard magnetic compass.

Encoding of head direction by hippocampal place cells in bats.

PubMed

Rubin, Alon; Yartsev, Michael M; Ulanovsky, Nachum

2014-01-15

Most theories of navigation rely on the concept of a mental map and compass. Hippocampal place cells are neurons thought to be important for representing the mental map; these neurons become active when the animal traverses a specific location in the environment (the "place field"). Head-direction cells are found outside the hippocampus, and encode the animal's head orientation, thus implementing a neural compass. The prevailing view is that the activity of head-direction cells is not tuned to a single place, while place cells do not encode head direction. However, little work has been done to investigate in detail the possible head-directional tuning of hippocampal place cells across species. Here we addressed this by recording the activity of single neurons in the hippocampus of two evolutionarily distant bat species, Egyptian fruit bat and big brown bat, which crawled randomly in three different open-field arenas. We found that a large fraction of hippocampal neurons, in both bat species, showed conjunctive sensitivity to the animal's spatial position (place field) and to its head direction. We introduced analytical methods to demonstrate that the head-direction tuning was significant even after controlling for the behavioral coupling between position and head direction. Surprisingly, some hippocampal neurons preserved their head direction tuning even outside the neuron's place field, suggesting that "spontaneous" extra-field spikes are not noise, but in fact carry head-direction information. Overall, these findings suggest that bat hippocampal neurons can convey both map information and compass information.

Quantifying navigational information: The catchment volumes of panoramic snapshots in outdoor scenes.

PubMed

Murray, Trevor; Zeil, Jochen

2017-01-01

Panoramic views of natural environments provide visually navigating animals with two kinds of information: they define locations because image differences increase smoothly with distance from a reference location and they provide compass information, because image differences increase smoothly with rotation away from a reference orientation. The range over which a given reference image can provide navigational guidance (its 'catchment area') has to date been quantified from the perspective of walking animals by determining how image differences develop across the ground plane of natural habitats. However, to understand the information available to flying animals there is a need to characterize the 'catchment volumes' within which panoramic snapshots can provide navigational guidance. We used recently developed camera-based methods for constructing 3D models of natural environments and rendered panoramic views at defined locations within these models with the aim of mapping navigational information in three dimensions. We find that in relatively open woodland habitats, catchment volumes are surprisingly large extending for metres depending on the sensitivity of the viewer to image differences. The size and the shape of catchment volumes depend on the distance of visual features in the environment. Catchment volumes are smaller for reference images close to the ground and become larger for reference images at some distance from the ground and in more open environments. Interestingly, catchment volumes become smaller when only above horizon views are used and also when views include a 1 km distant panorama. We discuss the current limitations of mapping navigational information in natural environments and the relevance of our findings for our understanding of visual navigation in animals and autonomous robots.

Quantifying navigational information: The catchment volumes of panoramic snapshots in outdoor scenes

PubMed Central

Zeil, Jochen

2017-01-01

Panoramic views of natural environments provide visually navigating animals with two kinds of information: they define locations because image differences increase smoothly with distance from a reference location and they provide compass information, because image differences increase smoothly with rotation away from a reference orientation. The range over which a given reference image can provide navigational guidance (its ‘catchment area’) has to date been quantified from the perspective of walking animals by determining how image differences develop across the ground plane of natural habitats. However, to understand the information available to flying animals there is a need to characterize the ‘catchment volumes’ within which panoramic snapshots can provide navigational guidance. We used recently developed camera-based methods for constructing 3D models of natural environments and rendered panoramic views at defined locations within these models with the aim of mapping navigational information in three dimensions. We find that in relatively open woodland habitats, catchment volumes are surprisingly large extending for metres depending on the sensitivity of the viewer to image differences. The size and the shape of catchment volumes depend on the distance of visual features in the environment. Catchment volumes are smaller for reference images close to the ground and become larger for reference images at some distance from the ground and in more open environments. Interestingly, catchment volumes become smaller when only above horizon views are used and also when views include a 1 km distant panorama. We discuss the current limitations of mapping navigational information in natural environments and the relevance of our findings for our understanding of visual navigation in animals and autonomous robots. PMID:29088300

Astronomical fire: Richard Carrington and the solar flare of 1859.

PubMed

Clark, Stuart

2007-09-01

An explosion on the Sun in 1859, serendipitously witnessed by amateur astronomer Richard Carrington, plunged telegraphic communications into chaos and bathed two thirds of the Earth's skies in aurorae. Explaining what happened to the Sun and how it could affect Earth, 93 million miles away, helped change the direction of astronomy. From being concerned principally with charting the stars to aid navigation, astronomers became increasingly concerned with what the celestial objects were, how they behaved and how they might affect life on Earth.

The advanced-stage therapy group.

PubMed

Berman, A; Weinberg, H

1998-10-01

Many authors describe a stage of maturity in the development of groups, but each highlights a different dimension. This article describes the characteristics of the advanced stage and the main axes along which it develops (internalization and containment, symbolization, self and self-other development, differentiation and individuation). It also offers a conceptual explanation for these developments and attempts to identify the conditions necessary for the emergence of this stage of maturity. An understanding of this stage and the conditions required for its development can be used by the group leader as a compass to help him or her navigate the group toward this objective.

The bee's map of the e-vector pattern in the sky.

PubMed

Rossel, S; Wehner, R

1982-07-01

It has long been known that bees can use the pattern of polarized light in the sky as a compass cue even if they can see only a small part of the whole pattern. How they solve this problem has remained enigmatic. Here we show that the bees rely on a generalized celestial map that is used invariably throughout the day. We reconstruct this map by analyzing the navigation errors made by bees to which single e-vectors are displayed. In addition, we demonstrate how the bee's celestial map can be derived from the e-vector patterns in the sky.

Maplike representation of celestial E-vector orientations in the brain of an insect.

PubMed

Heinze, Stanley; Homberg, Uwe

2007-02-16

For many insects, the polarization pattern of the blue sky serves as a compass cue for spatial navigation. E-vector orientations are detected by photoreceptors in a dorsal rim area of the eye. Polarized-light signals from both eyes are finally integrated in the central complex, a brain area consisting of two subunits, the protocerebral bridge and the central body. Here we show that a topographic representation of zenithal E-vector orientations underlies the columnar organization of the protocerebral bridge in a locust. The maplike arrangement is highly suited to signal head orientation under the open sky.

Velocity, water-quality, and bathymetric surveys of the Grays Landing and Maxwell Navigation Pools, and Selected Tributaries to the Monongahela River, Pennsylvania, 2010–11

USGS Publications Warehouse

Hoffman, Scott A.; Roland, Mark A.; Schalk, Luther F.; Fulton, John W.

2013-01-01

The U.S. Geological Survey (USGS) conducted velocity, water-quality, and bathymetric surveys from spring 2010 to summer 2011 in the Grays Landing and Maxwell navigation pools of the Monongahela River, Pennsylvania, and selected tributaries in response to elevated levels of total dissolved solids (TDS) recorded in early September 2009. Velocity data were collected using an Acoustic Doppler Current Profiler. Water-quality surveys included the in-situ collection of specific-conductance, water-temperature, and turbidity data using a water-quality sonde. Additionally, discrete water samples were collected and analyzed for TDS, chloride, and sulfate. Bathymetric data were collected using an echo sounder, and the shoreline was delineated using a laser range finder and electronic compass. The data were geo-referenced using a differential global positioning system and navigational software. Horizontal (x, y) coordinates were referenced to the North American Datum of 1983. Depth (z) elevations were referenced to the North American Vertical Datum of 1988. The data are provided in electronic format (appendix 1) and may be downloaded and can be used in a geographic information system for cartographic display and data analysis.

Releases of surgically deafened homing pigeons indicate that aural cues play a significant role in their navigational system.

PubMed

Hagstrum, Jonathan T; Manley, Geoffrey A

2015-10-01

Experienced homing pigeons with extirpated cochleae and lagenae were released from six sites in upstate New York and western Pennsylvania on 17 days between 1973 and 1975 by William T. Keeton and his co-workers at Cornell University. The previously unpublished data indicate that departure directions of the operated birds were significantly different from those of sham-operated control birds (314 total), indicating that aural cues play an important part in the pigeon's navigational system. Moreover, propagation modeling of infrasonic waves using meteorological data for the release days supports the possibility that control birds used infrasonic signals to determine their homeward direction. Local acoustic 'shadow' zones, therefore, could have caused initial disorientation of control birds at release sites where they were normally well oriented. Experimental birds plausibly employed an alternate 'route-reversal' strategy to return home perhaps using their ocular-based magnetic compass. We suggest, based on Keeton's results from another site of long-term disorientation, that experienced pigeons depend predominantly on infrasonic cues for initial orientation, and that surgical removal of their aural sense compelled them to switch to a secondary navigational strategy.

Honeybees as a model for the study of visually guided flight, navigation, and biologically inspired robotics.

PubMed

Srinivasan, Mandyam V

2011-04-01

Research over the past century has revealed the impressive capacities of the honeybee, Apis mellifera, in relation to visual perception, flight guidance, navigation, and learning and memory. These observations, coupled with the relative ease with which these creatures can be trained, and the relative simplicity of their nervous systems, have made honeybees an attractive model in which to pursue general principles of sensorimotor function in a variety of contexts, many of which pertain not just to honeybees, but several other animal species, including humans. This review begins by describing the principles of visual guidance that underlie perception of the world in three dimensions, obstacle avoidance, control of flight speed, and orchestrating smooth landings. We then consider how navigation over long distances is accomplished, with particular reference to how bees use information from the celestial compass to determine their flight bearing, and information from the movement of the environment in their eyes to gauge how far they have flown. Finally, we illustrate how some of the principles gleaned from these studies are now being used to design novel, biologically inspired algorithms for the guidance of unmanned aerial vehicles.

An analysis of clock-shift experiments: is scatter increased and deflection reduced in clock-shifted homing pigeons?

PubMed

Chappell

1997-01-01

Clock-shifting (altering the phase of the internal clock) in homing pigeons leads to a deflection in the vanishing bearing of the clock-shifted group relative to controls. However, two unexplained phenomena are common in clock-shift experiments: the vanishing bearings of the clock-shifted group are often more scattered (with a shorter vector length) than those of the control group, and the deflection of the mean bearing of the clock-shifted group from that of the controls is often smaller than expected theoretically. Here, an analysis of 55 clock-shift experiments performed in four countries over 21 years is reported. The bearings of the clock-shifted groups were significantly more scattered than those of controls and less deflected than expected, but these effects were not significantly different at familiar and unfamiliar sites. The possible causes of the effects are discussed and evaluated with reference to this analysis and other experiments. The most likely causes appear to be conflict between the directions indicated by the sun compass and either unshifted familiar visual landmarks (at familiar sites only) or the unshifted magnetic compass (possible at both familiar and unfamiliar sites).

GNSS/Electronic Compass/Road Segment Information Fusion for Vehicle-to-Vehicle Collision Avoidance Application

PubMed Central

Cheng, Qi; Xue, Dabin; Wang, Guanyu; Ochieng, Washington Yotto

2017-01-01

The increasing number of vehicles in modern cities brings the problem of increasing crashes. One of the applications or services of Intelligent Transportation Systems (ITS) conceived to improve safety and reduce congestion is collision avoidance. This safety critical application requires sub-meter level vehicle state estimation accuracy with very high integrity, continuity and availability, to detect an impending collision and issue a warning or intervene in the case that the warning is not heeded. Because of the challenging city environment, to date there is no approved method capable of delivering this high level of performance in vehicle state estimation. In particular, the current Global Navigation Satellite System (GNSS) based collision avoidance systems have the major limitation that the real-time accuracy of dynamic state estimation deteriorates during abrupt acceleration and deceleration situations, compromising the integrity of collision avoidance. Therefore, to provide the Required Navigation Performance (RNP) for collision avoidance, this paper proposes a novel Particle Filter (PF) based model for the integration or fusion of real-time kinematic (RTK) GNSS position solutions with electronic compass and road segment data used in conjunction with an Autoregressive (AR) motion model. The real-time vehicle state estimates are used together with distance based collision avoidance algorithms to predict potential collisions. The algorithms are tested by simulation and in the field representing a low density urban environment. The results show that the proposed algorithm meets the horizontal positioning accuracy requirement for collision avoidance and is superior to positioning accuracy of GNSS only, traditional Constant Velocity (CV) and Constant Acceleration (CA) based motion models, with a significant improvement in the prediction accuracy of potential collision. PMID:29186851

GNSS/Electronic Compass/Road Segment Information Fusion for Vehicle-to-Vehicle Collision Avoidance Application.

PubMed

Sun, Rui; Cheng, Qi; Xue, Dabin; Wang, Guanyu; Ochieng, Washington Yotto

2017-11-25

The increasing number of vehicles in modern cities brings the problem of increasing crashes. One of the applications or services of Intelligent Transportation Systems (ITS) conceived to improve safety and reduce congestion is collision avoidance. This safety critical application requires sub-meter level vehicle state estimation accuracy with very high integrity, continuity and availability, to detect an impending collision and issue a warning or intervene in the case that the warning is not heeded. Because of the challenging city environment, to date there is no approved method capable of delivering this high level of performance in vehicle state estimation. In particular, the current Global Navigation Satellite System (GNSS) based collision avoidance systems have the major limitation that the real-time accuracy of dynamic state estimation deteriorates during abrupt acceleration and deceleration situations, compromising the integrity of collision avoidance. Therefore, to provide the Required Navigation Performance (RNP) for collision avoidance, this paper proposes a novel Particle Filter (PF) based model for the integration or fusion of real-time kinematic (RTK) GNSS position solutions with electronic compass and road segment data used in conjunction with an Autoregressive (AR) motion model. The real-time vehicle state estimates are used together with distance based collision avoidance algorithms to predict potential collisions. The algorithms are tested by simulation and in the field representing a low density urban environment. The results show that the proposed algorithm meets the horizontal positioning accuracy requirement for collision avoidance and is superior to positioning accuracy of GNSS only, traditional Constant Velocity (CV) and Constant Acceleration (CA) based motion models, with a significant improvement in the prediction accuracy of potential collision.

Relative Navigation of Formation Flying Satellites

NASA Technical Reports Server (NTRS)

Long, Anne; Kelbel, David; Lee, Taesul; Leung, Dominic; Carpenter, Russell; Gramling, Cheryl; Bauer, Frank (Technical Monitor)

2002-01-01

The Guidance, Navigation, and Control Center (GNCC) at Goddard Space Flight Center (GSFC) has successfully developed high-accuracy autonomous satellite navigation systems using the National Aeronautics and Space Administration's (NASA's) space and ground communications systems and the Global Positioning System (GPS). In addition, an autonomous navigation system that uses celestial object sensor measurements is currently under development and has been successfully tested using real Sun and Earth horizon measurements.The GNCC has developed advanced spacecraft systems that provide autonomous navigation and control of formation flyers in near-Earth, high-Earth, and libration point orbits. To support this effort, the GNCC is assessing the relative navigation accuracy achievable for proposed formations using GPS, intersatellite crosslink, ground-to-satellite Doppler, and celestial object sensor measurements. This paper evaluates the performance of these relative navigation approaches for three proposed missions with two or more vehicles maintaining relatively tight formations. High-fidelity simulations were performed to quantify the absolute and relative navigation accuracy as a function of navigation algorithm and measurement type. Realistically-simulated measurements were processed using the extended Kalman filter implemented in the GPS Enhanced Inboard Navigation System (GEONS) flight software developed by GSFC GNCC. Solutions obtained by simultaneously estimating all satellites in the formation were compared with the results obtained using a simpler approach based on differencing independently estimated state vectors.

To the North Coast of Devon: Collaborative Navigation While Exploring Unfamiliar Terrain

NASA Technical Reports Server (NTRS)

Clancey, William J.; Lee, Pascal; Cockell, Charles S.; Braham, Stephen; Shafto, Mike

2006-01-01

Navigation-knowing where one is and finding a safe route-is a fundamental aspect of all exploration. In unfamiliar terrain, one may use maps and instruments such as a compass or binoculars to assist, and people often collaborate in finding their way. This paper analyzes a group of people driving a humvee from a base camp to the north coast of Devon Island in the High Canadian Arctic. A complete audio recording and video during most stops allows a quantitative and semantic analysis of the conversations when the team stopped to take bearings and replan a route. Over a period of 2 hours, the humvee stopped 20 times, with an average duration of 3.15 min/pause and 3.85 min moving forward. The team failed to reach its goal due to difficult terrain causing mechanical problems. The analysis attempts to explain these facts by considering a variety of complicating factors, especially the navigation problem of relating maps and the world to locate the humvee and to plan a route. The analysis reveals patterns in topic structure and turn-taking, supporting the view that the collaboration was efficient, but the tools and information were inadequate for the task. This work is relevant for planning and training for planetary surface missions, as well as developing computer systems that could aid navigation.

The orientation and navigation of juvenile alligators: evidence of magnetic sensitivity

USGS Publications Warehouse

Rodda, Gordon H.

1984-01-01

Displaced juvenile alligators, Alligator mississipiensis, were released on land in a 9 m diameter dodecagonal arena to test their ability to orient in the absence of terrestrial landmarks. Navigational ability seemed to improve with age. When displaced along a fairly direct route yearlings (age 7–14 months) compensated for their displacement, moving in the direction from the arena to their home sites. When displaced by a circuitous route, yearlings failed to compensate for their displacement, exhibiting instead simple compass orientation in a direction that would have returned them to water had they been released on land near the site where they were captured. The older juveniles were oriented in a homeward direction under all displacement and test conditions. The latter animals may have been using geomagnetic map information to select their homeward directions as the errors in their homeward bearings correlated with small deviations in the geomagnetic field's dip angle at the time of the test (1980r s=−0.6047,P=0.0131, all testsr s= −0.4652,P=0.0084). This effect appeared to depend on a very short-term assessment of geomagnetic conditions, as values measured 20 min before or 30 min after the tests began did not correlate with the directions the animals moved. The older juveniles appeared to use magnetically quiet hours on the night of their capture as the baseline from which to measure the geomagnetic deviations that occurred at the time of the arena test. The magnitude of the magnetic effect in the older animals suggests that the geomagnetic information may have been used to perform a ‘map’ step, as small fluctuations in dip angle correlated with much larger deviations in homeward bearings. In addition, the compass-oriented yearlings and the seemingly route-based behavior of the homeward-oriented yearlings did not appear to be influenced by geomagnetic conditions. These findings have many parallels in results obtained from bird orientation studies, providing evidence that navigation may share a common basis in different vertebrate groups.

A Type of Non-cable Self-Posioning Seismograph Served For SinoProbe Project In China

NASA Astrophysics Data System (ADS)

Yang, H.; Lin, J.; Chen, Z.; Zhang, L.; Huaizhu, Z.; Zheng, F.; Seismic Instrument Design Team

2011-12-01

A type of cableless self-positioning telemetry seismograph designed for deep exploration is introduced in this article. The seismograph adopts 24-bit ADC and the analog circuits are designed carefully to attain a low noise level of 300nV RMS. It also uses 24-bit DAC and FPGA circuits to perform self-test including noise level, trace crosstalk, CMRR, harmonic distortion, geophone resitor testing, pulse testing, gain calibration and etc. As the testing result shows, the analog acquisition performances are similar to the most popular seismograph 428XL system from Sercel. However, the seismograph has a different structure with 428XL. It gets rid of cables and stores seismic data in mass non-volatile memory, and meanwhile it employs GPS combined with Compass global navigation satellite system to implement synchronous data aquisiton and self-positioning. In addition, the seismograph has a built-in WiFi module and can communicate with a cental server in Ad-hoc mode or AP mode depending on the distance between the seismograph and the central server. The working status and seismic data quality can be monitored through the WiFi network and some seismic data can be transmitted back on demand. When the distance between adjacent seismographs exceed 500 metres, the Compass global navigation satellite system which supports global communication can be used to send necessary data. At last, dynamic power management is emplyed and the system working voltage and frequency will be changed as the system runs into different status, and also all circuit modules can be switched off when not needed. Because of all the benefits listed above, the seismograph can be used in a variety of ways as needed, such as seismic network, deep seismic reflection exploration, wide-angle seismic reflection and refraction exploration, ore zone seismic exploration and etc. To sum up, the cable-less self-positioning seismograph employs mass non-volatile storage technology, global navigation satellite sytem, WiFi modules and dynamic power management technology to attain a flexible data acquisition system suitable for most of the seismic deep exploration in SinoProbe launched in China.

Navigation Concepts for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Long, Anne; Leung, Dominic; Kelbel, David; Beckman, Mark; Grambling, Cheryl

2003-01-01

This paper evaluates the performance that can be achieved using candidate ground and onboard navigation approaches for operation of the James Webb Space Telescope, which will be in an orbit about the Sun-Earth L2 libration point. The ground navigation approach processes standard range and Doppler measurements from the Deep Space Network The onboard navigation approach processes celestial object measurements and/or ground-to- spacecraft Doppler measurements to autonomously estimate the spacecraft s position and velocity and Doppler reference frequency. Particular attention is given to assessing the absolute position and velocity accuracy that can be achieved in the presence of the frequent spacecraft reorientations and momentum unloads planned for this mission. The ground navigation approach provides stable navigation solutions using a tracking schedule of one 30-minute contact per day. The onboard navigation approach that uses only optical quality celestial object measurements provides stable autonomous navigation solutions. This study indicates that unmodeled changes in the solar radiation pressure cross-sectional area and modeled momentum unload velocity changes are the major error sources. These errors can be mitigated by modeling these changes, by estimating corrections to compensate for the changes, or by including acceleration measurements.

Adjustment errors of sunstones in the first step of sky-polarimetric Viking navigation: studies with dichroic cordierite/ tourmaline and birefringent calcite crystals

PubMed Central

Száz, Dénes; Farkas, Alexandra; Blahó, Miklós; Barta, András; Egri, Ádám; Kretzer, Balázs; Hegedüs, Tibor; Jäger, Zoltán; Horváth, Gábor

2016-01-01

According to an old but still unproven theory, Viking navigators analysed the skylight polarization with dichroic cordierite or tourmaline, or birefringent calcite sunstones in cloudy/foggy weather. Combining these sunstones with their sun-dial, they could determine the position of the occluded sun, from which the geographical northern direction could be guessed. In psychophysical laboratory experiments, we studied the accuracy of the first step of this sky-polarimetric Viking navigation. We measured the adjustment error e of rotatable cordierite, tourmaline and calcite crystals when the task was to determine the direction of polarization of white light as a function of the degree of linear polarization p. From the obtained error functions e(p), the thresholds p* above which the first step can still function (i.e. when the intensity change seen through the rotating analyser can be sensed) were derived. Cordierite is about twice as reliable as tourmaline. Calcite sunstones have smaller adjustment errors if the navigator looks for that orientation of the crystal where the intensity difference between the two spots seen in the crystal is maximal, rather than minimal. For higher p (greater than pcrit) of incident light, the adjustment errors of calcite are larger than those of the dichroic cordierite (pcrit=20%) and tourmaline (pcrit=45%), while for lower p (less than pcrit) calcite usually has lower adjustment errors than dichroic sunstones. We showed that real calcite crystals are not as ideal sunstones as it was believed earlier, because they usually contain scratches, impurities and crystal defects which increase considerably their adjustment errors. Thus, cordierite and tourmaline can also be at least as good sunstones as calcite. Using the psychophysical e(p) functions and the patterns of the degree of skylight polarization measured by full-sky imaging polarimetry, we computed how accurately the northern direction can be determined with the use of the Viking sun-dial under 10 different sky conditions at 61° latitude, which was one of the main Viking sailing routes. According to our expermiments, under clear skies, using calcite or cordierite or tourmaline sunstones, Viking sailors could navigate with net orientation errors |Σmax|≤3∘. Under overcast conditions, their net navigation error depends on the sunstone type: |Σmax(calcite)|≤6∘, |Σmax(cordierite)|≤10∘ and |Σmax(tourmaline)|≤17∘. PMID:26909167

Compass cues used by a nocturnal bull ant, Myrmecia midas.

PubMed

Freas, Cody A; Narendra, Ajay; Cheng, Ken

2017-05-01

Ants use both terrestrial landmarks and celestial cues to navigate to and from their nest location. These cues persist even as light levels drop during the twilight/night. Here, we determined the compass cues used by a nocturnal bull ant, Myrmecia midas , in which the majority of individuals begin foraging during the evening twilight period. Myrmecia midas foragers with vectors of ≤5   m when displaced to unfamiliar locations did not follow the home vector, but instead showed random heading directions. Foragers with larger home vectors (≥10   m) oriented towards the fictive nest, indicating a possible increase in cue strength with vector length. When the ants were displaced locally to create a conflict between the home direction indicated by the path integrator and terrestrial landmarks, foragers oriented using landmark information exclusively and ignored any accumulated home vector regardless of vector length. When the visual landmarks at the local displacement site were blocked, foragers were unable to orient to the nest direction and their heading directions were randomly distributed. Myrmecia midas ants typically nest at the base of the tree and some individuals forage on the same tree. Foragers collected on the nest tree during evening twilight were unable to orient towards the nest after small lateral displacements away from the nest. This suggests the possibility of high tree fidelity and an inability to extrapolate landmark compass cues from information collected on the tree and at the nest site to close displacement sites. © 2017. Published by The Company of Biologists Ltd.

Safety Ellipse Motion with Coarse Sun Angle Optimization

NASA Technical Reports Server (NTRS)

Naasz, Bo

2005-01-01

The Hubble Space Telescope Robotic Servicing and De-orbit Mission (HRSDM) was t o be performed by the unmanned Hubble Robotic Vehicle (HRV) consisting of a Deorbit Module (DM), responsible for the ultimate disposal of Hubble Space Telescope (HST) at the end of science operations, and an Ejection Module (EM), responsible for robotically servicing the HST to extend its useful operational lifetime. HRSDM consisted of eight distinct phases, including: launch, pursuit, proximity operations, capture, servicing, EM jettison and disposal, science operations, and deorbit. The scope of this paper is limited to the Proximity Operations phase of HRSDM. It introduces a relative motion strategy useful for Autonomous Rendezvous and Docking (AR&D) or Formation Flying missions where safe circumnavigation trajectories, or close proximity operations (tens or hundreds of meters) are required for extended periods of time. Parameters and algorithms used to model the relative motion of HRV with respect to HST during the Proximity Operations phase of the HRSDM are described. Specifically, the Safety Ellipse (SE) concept, convenient parameters for describing SE motion, and a concept for initializing SE motion around a target vehicle to coarsely optimize sun and relative navigation sensor angles are presented. The effects of solar incidence angle variations on sun angle optimization, and the effects of orbital perturbations and navigation uncertainty on long term SE motion are discussed.

Classroom Planetarium

NASA Astrophysics Data System (ADS)

Horia Minda, Octavian

2016-04-01

Teachers,especially at the elementary level, have little or no background in astronomy or astronomy teaching. Astronomy is often considered irrelevant by education authorities because it has no apparent economic value. Astronomy still has practical applications to timekeeping; calendars; daily, seasonal and long-term changes in climate and navigation. It deals with the external environmental influences on the earth: the radiation and articles from the Sun, the gravitational influences of the Sun and Moon, the impacts of asteroids and comets. My poster presents one of the activities I realized with my students . Subject: Space Science Grade: 7-8 years old Duration: Two class periods Objectives: Students will: • Understand the relationship of the nine planets in our solar system to the sun by creating a three-dimensional representation. • Understand the planets' relative distance from the sun and their approximate size in relation to the Earth. It is a interdisciplinary activity: science, handwork, mathematics. The poster presents photos of this activity.

Reclaiming Celestial Navigation Using a Contemporary Hawaiian Worldview of the Heavens

NASA Astrophysics Data System (ADS)

Dye, Ahia G.; Ha`o, Celeste; Slater, Timothy F.; Slater, Stephanie J.

2015-08-01

The immense challenges of successfully navigating the vast Pacific basin without modern instruments are well-known. At the same time, the precise methods used by ancient Polynesian wayfinders are largely undocumented, the strategies being wholly unfamiliar to early European navigators from higher latitudes with formal training in charts and tables. Leading the wave of a Hawaiian-Renaissance, contemporary Hawaiian seafarers are boldly reclaiming their heritage by recreating and sailing double hulled canoes by instrument-free, navigation techniques. Many of these navigational techniques are probably reminiscent of earlier strategies, and are proving to be highly successful. The result is that numerous canoes are now making repeated trips throughout the Polynesian Triangle, and reaching beyond to soon circumnavigate the globe. Not surprisingly, a vital component of any navigational system far from terrestrial landmarks is based on the changing positions and predictable motions of the Sun and stars. Although many of the indigenous star names are lost to history, some of the most important star names for celestial navigation have been painstakingly re-claimed. Other critically important navigational stars are being named by the respected Hawaiian Guild Navigators and their teams of educators who are conducting navigation training for Hawaiian sailing crews. The authors are collecting and documenting these new star names along-with their identifiable asterisms-in the service of educating both the public and the next generation of navigators.

Navigational Efficiency of Nocturnal Myrmecia Ants Suffers at Low Light Levels

PubMed Central

Narendra, Ajay; Reid, Samuel F.; Raderschall, Chloé A.

2013-01-01

Insects face the challenge of navigating to specific goals in both bright sun-lit and dim-lit environments. Both diurnal and nocturnal insects use quite similar navigation strategies. This is despite the signal-to-noise ratio of the navigational cues being poor at low light conditions. To better understand the evolution of nocturnal life, we investigated the navigational efficiency of a nocturnal ant, Myrmecia pyriformis, at different light levels. Workers of M. pyriformis leave the nest individually in a narrow light-window in the evening twilight to forage on nest-specific Eucalyptus trees. The majority of foragers return to the nest in the morning twilight, while few attempt to return to the nest throughout the night. We found that as light levels dropped, ants paused for longer, walked more slowly, the success in finding the nest reduced and their paths became less straight. We found that in both bright and dark conditions ants relied predominantly on visual landmark information for navigation and that landmark guidance became less reliable at low light conditions. It is perhaps due to the poor navigational efficiency at low light levels that the majority of foragers restrict navigational tasks to the twilight periods, where sufficient navigational information is still available. PMID:23484052

Coupling Vanishing Point Tracking with Inertial Navigation to Estimate Attitude in a Structured Environment

DTIC Science & Technology

2011-03-01

with the Earth but does follow the Earth’s orbit around the sun . Though it is not a true inertial frame, for the sake of terrestrial navigation it can...the center of the Earth , with the x and y-axes on the equatorial plane and the z- axis along the Earth’s axis of rotation. The i-frame does not spin...be considered as such. Earth -centered Earth -fixed frame (e-frame) - The origin is fixed at the center of the Earth , with the x- axis on the equatorial

Straight as an arrow: humpback whales swim constant course tracks during long-distance migration

PubMed Central

Horton, Travis W.; Holdaway, Richard N.; Zerbini, Alexandre N.; Hauser, Nan; Garrigue, Claire; Andriolo, Artur; Clapham, Phillip J.

2011-01-01

Humpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 1° precision, despite the effects of variable sea-surface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored. PMID:21508023

Straight as an arrow: humpback whales swim constant course tracks during long-distance migration.

PubMed

Horton, Travis W; Holdaway, Richard N; Zerbini, Alexandre N; Hauser, Nan; Garrigue, Claire; Andriolo, Artur; Clapham, Phillip J

2011-10-23

Humpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 1° precision, despite the effects of variable sea-surface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored.

Apollo 13 Guidance, Navigation, and Control Challenges

NASA Technical Reports Server (NTRS)

Goodman, John L.

2009-01-01

Combustion and rupture of a liquid oxygen tank during the Apollo 13 mission provides lessons and insights for future spacecraft designers and operations personnel who may never, during their careers, have participated in saving a vehicle and crew during a spacecraft emergency. Guidance, Navigation, and Control (GNC) challenges were the reestablishment of attitude control after the oxygen tank incident, re-establishment of a free return trajectory, resolution of a ground tracking conflict between the LM and the Saturn V S-IVB stage, Inertial Measurement Unit (IMU) alignments, maneuvering to burn attitudes, attitude control during burns, and performing manual GNC tasks with most vehicle systems powered down. Debris illuminated by the Sun and gaseous venting from the Service Module (SM) complicated crew attempts to identify stars and prevented execution of nominal IMU alignment procedures. Sightings on the Sun, Moon, and Earth were used instead. Near continuous communications with Mission Control enabled the crew to quickly perform time critical procedures. Overcoming these challenges required the modification of existing contingency procedures.

The UAV take-off and landing system used for small areas of mobile vehicles

NASA Astrophysics Data System (ADS)

Ren, Tian-Yu; Duanmu, Qing-Duo; Wu, Bo-Qi

2018-03-01

In order to realize an UAV formation cluster system based on the current GPS and the fault and insufficiency of Beidou integrated navigation system in strong jamming environment. Due to the impact of the compass on the plane crash, navigation system error caused by the mobile area to help reduce the need for large landing sites and not in the small fast moving area to achieve the reality of the landing. By using Strapdown inertial and all-optical system to form Composite UAV flight control system, the photoelectric composite strapdown inertial coupling is realized, and through the laser and microwave telemetry link compound communication mechanism, using all-optical strapdown inertial and visual navigation system to solve the deviation of take-off and landing caused by electromagnetic interference, all-optical bidirectional data link realizes two-way position correction of landing site and aircraft, thus achieves the accurate recovery of UAV formation cluster in the mobile narrow area which the traditional navigation system can't realize. This system is a set of efficient unmanned aerial vehicle Group Take-off/descending system, which is suitable for many tasks, and not only realizes the reliable continuous navigation under the complex electromagnetic interference environment, moreover, the intelligent flight and Take-off and landing of unmanned aerial vehicles relative to the fast moving and small recovery sites in complex electromagnetic interference environment can not only improve the safe operation rate of unmanned aerial vehicle, but also guarantee the operation safety of the aircraft, and the more has important social value for the application foreground of the aircraft.

Implementation of an oblique-sectioning visualization tool for line-of-sight stereotactic neurosurgical navigation using the AVW toolkit

NASA Astrophysics Data System (ADS)

Bates, Lisa M.; Hanson, Dennis P.; Kall, Bruce A.; Meyer, Frederic B.; Robb, Richard A.

1998-06-01

An important clinical application of biomedical imaging and visualization techniques is provision of image guided neurosurgical planning and navigation techniques using interactive computer display systems in the operating room. Current systems provide interactive display of orthogonal images and 3D surface or volume renderings integrated with and guided by the location of a surgical probe. However, structures in the 'line-of-sight' path which lead to the surgical target cannot be directly visualized, presenting difficulty in obtaining full understanding of the 3D volumetric anatomic relationships necessary for effective neurosurgical navigation below the cortical surface. Complex vascular relationships and histologic boundaries like those found in artereovenous malformations (AVM's) also contribute to the difficulty in determining optimal approaches prior to actual surgical intervention. These difficulties demonstrate the need for interactive oblique imaging methods to provide 'line-of-sight' visualization. Capabilities for 'line-of- sight' interactive oblique sectioning are present in several current neurosurgical navigation systems. However, our implementation is novel, in that it utilizes a completely independent software toolkit, AVW (A Visualization Workshop) developed at the Mayo Biomedical Imaging Resource, integrated with a current neurosurgical navigation system, the COMPASS stereotactic system at Mayo Foundation. The toolkit is a comprehensive, C-callable imaging toolkit containing over 500 optimized imaging functions and structures. The powerful functionality and versatility of the AVW imaging toolkit provided facile integration and implementation of desired interactive oblique sectioning using a finite set of functions. The implementation of the AVW-based code resulted in higher-level functions for complete 'line-of-sight' visualization.

Molecular and phylogenetic analyses reveal mammalian-like clockwork in the honey bee (Apis mellifera) and shed new light on the molecular evolution of the circadian clock.

PubMed

Rubin, Elad B; Shemesh, Yair; Cohen, Mira; Elgavish, Sharona; Robertson, Hugh M; Bloch, Guy

2006-11-01

The circadian clock of the honey bee is implicated in ecologically relevant complex behaviors. These include time sensing, time-compensated sun-compass navigation, and social behaviors such as coordination of activity, dance language communication, and division of labor. The molecular underpinnings of the bee circadian clock are largely unknown. We show that clock gene structure and expression pattern in the honey bee are more similar to the mouse than to Drosophila. The honey bee genome does not encode an ortholog of Drosophila Timeless (Tim1), has only the mammalian type Cryptochrome (Cry-m), and has a single ortholog for each of the other canonical "clock genes." In foragers that typically have strong circadian rhythms, brain mRNA levels of amCry, but not amTim as in Drosophila, consistently oscillate with strong amplitude and a phase similar to amPeriod (amPer) under both light-dark and constant darkness illumination regimes. In contrast to Drosophila, the honey bee amCYC protein contains a transactivation domain and its brain transcript levels oscillate at virtually an anti-phase to amPer, as it does in the mouse. Phylogenetic analyses indicate that the basal insect lineage had both the mammalian and Drosophila types of Cry and Tim. Our results suggest that during evolution, Drosophila diverged from the ancestral insect clock and specialized in using a set of clock gene orthologs that was lost by both mammals and bees, which in turn converged and specialized in the other set. These findings illustrate a previously unappreciated diversity of insect clockwork and raise critical questions concerning the evolution and functional significance of species-specific variation in molecular clockwork.

Defining behavioral and molecular differences between summer and migratory monarch butterflies

PubMed Central

Zhu, Haisun; Gegear, Robert J; Casselman, Amy; Kanginakudru, Sriramana; Reppert, Steven M

2009-01-01

Background In the fall, Eastern North American monarch butterflies (Danaus plexippus) undergo a magnificent long-range migration. In contrast to spring and summer butterflies, fall migrants are juvenile hormone deficient, which leads to reproductive arrest and increased longevity. Migrants also use a time-compensated sun compass to help them navigate in the south/southwesterly direction en route for Mexico. Central issues in this area are defining the relationship between juvenile hormone status and oriented flight, critical features that differentiate summer monarchs from fall migrants, and identifying molecular correlates of behavioral state. Results Here we show that increasing juvenile hormone activity to induce summer-like reproductive development in fall migrants does not alter directional flight behavior or its time-compensated orientation, as monitored in a flight simulator. Reproductive summer butterflies, in contrast, uniformly fail to exhibit directional, oriented flight. To define molecular correlates of behavioral state, we used microarray analysis of 9417 unique cDNA sequences. Gene expression profiles reveal a suite of 40 genes whose differential expression in brain correlates with oriented flight behavior in individual migrants, independent of juvenile hormone activity, thereby molecularly separating fall migrants from summer butterflies. Intriguing genes that are differentially regulated include the clock gene vrille and the locomotion-relevant tyramine beta hydroxylase gene. In addition, several differentially regulated genes (37.5% of total) are not annotated. We also identified 23 juvenile hormone-dependent genes in brain, which separate reproductive from non-reproductive monarchs; genes involved in longevity, fatty acid metabolism, and innate immunity are upregulated in non-reproductive (juvenile-hormone deficient) migrants. Conclusion The results link key behavioral traits with gene expression profiles in brain that differentiate migratory from summer butterflies and thus show that seasonal changes in genomic function help define the migratory state. PMID:19335876

The relationships among health promotion behaviors, compassion fatigue, burnout, and compassion satisfaction in nurses practicing in a community medical center.

PubMed

Neville, Kathleen; Cole, Donna A

2013-06-01

The objective of this study was to examine the relationships among health promotion behaviors, compassion fatigue, burnout, and compassion satisfaction among nurses practicing in a community medical center. Compassion fatigue and burnout are significant nursing stressors. Programs are available to offset the negative consequence of compassion fatigue and burnout and enhance compassion satisfaction, yet there remains a paucity of literature examining the relationships between health promotion behaviors, compassion fatigue, burnout, and compassion satisfaction. A nonexperimental design using a convenience sample of nurses completed the Health Promoting Lifestyle Profile II, the Professional Quality of Life Scale, and a demographic data sheet. Statistically significant relationships among health promotional behaviors and compassion fatigue, compassion satisfaction, and burnout were identified. Compassion fatigue, burnout, and compassion satisfaction are outcomes associated with nursing practice. Support for engagement in health promotional behaviors may contribute to nurses' well-being in counteracting compassion fatigue and burnout and enhancing compassion satisfaction.

Polarized skylight navigation.

PubMed

Hamaoui, Moshe

2017-01-20

Vehicle state estimation is an essential prerequisite for navigation. The present approach seeks to use skylight polarization to facilitate state estimation under autonomous unconstrained flight conditions. Atmospheric scattering polarizes incident sunlight such that solar position is mathematically encoded in the resulting skylight polarization pattern. Indeed, several species of insects are able to sense skylight polarization and are believed to navigate polarimetrically. Sun-finding methodologies for polarized skylight navigation (PSN) have been proposed in the literature but typically rely on calibration updates to account for changing atmospheric conditions and/or are limited to 2D operation. To address this technology gap, a gradient-based PSN solution is developed based upon the Rayleigh sky model. The solution is validated in simulation, and effects of measurement error and changing atmospheric conditions are investigated. Finally, an experimental effort is described wherein polarimetric imagery is collected, ground-truth is established through independent imager-attitude measurement, the gradient-based PSN solution is applied, and results are analyzed.

Measuring Global Position Using the Sun

ERIC Educational Resources Information Center

Murphy, Evan; Hughes, Stephen

2014-01-01

The determination of latitude and longitude on Earth has always been of interest to explorers and cartographers alike. Accurate positional information is often needed for rescue purposes in locations where satellite navigational systems are inoperable. The activity described in this paper demonstrates a simple procedure to determine latitude and…

A pilot study exploring the relationship between self-compassion, self-judgement, self-kindness, compassion, professional quality of life and wellbeing among UK community nurses.

PubMed

Durkin, Mark; Beaumont, Elaine; Hollins Martin, Caroline J; Carson, Jerome

2016-11-01

Compassion fatigue and burnout can impact on performance of nurses. This paper explores the relationship between self-compassion, self-judgement, self-kindness, compassion, professional quality of life, and wellbeing among community nurses. To measure associations between self-compassion, compassion fatigue, wellbeing, and burnout in community nurses. Quantitative data were collected using standardised psychometric questionnaires: (1) Professional Quality of Life Scale; (2) Self-Compassion Scale; (3) short Warwick Edinburgh Mental Wellbeing Scale; (4) Compassion For Others Scale, used to measure relationships between self-compassion, compassion fatigue, wellbeing, and burnout. A cross sectional sample of registered community nurses (n=37) studying for a postgraduate diploma at a University in the North of England took part in this study. Results show that community nurses who score high on measures of self-compassion and wellbeing, also report less burnout. Greater compassion satisfaction was also positively associated with compassion for others, and wellbeing, whilst also being negatively correlated with burnout. High levels of self-compassion were linked with lower levels of burnout. Furthermore when community nurses have greater compassion satisfaction they also report more compassion for others, increased wellbeing, and less burnout. The implications of this are discussed alongside suggestions for the promotion of greater compassion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Heading-vector navigation based on head-direction cells and path integration.

PubMed

Kubie, John L; Fenton, André A

2009-05-01

Insect navigation is guided by heading vectors that are computed by path integration. Mammalian navigation models, on the other hand, are typically based on map-like place representations provided by hippocampal place cells. Such models compute optimal routes as a continuous series of locations that connect the current location to a goal. We propose a "heading-vector" model in which head-direction cells or their derivatives serve both as key elements in constructing the optimal route and as the straight-line guidance during route execution. The model is based on a memory structure termed the "shortcut matrix," which is constructed during the initial exploration of an environment when a set of shortcut vectors between sequential pairs of visited waypoint locations is stored. A mechanism is proposed for calculating and storing these vectors that relies on a hypothesized cell type termed an "accumulating head-direction cell." Following exploration, shortcut vectors connecting all pairs of waypoint locations are computed by vector arithmetic and stored in the shortcut matrix. On re-entry, when local view or place representations query the shortcut matrix with a current waypoint and goal, a shortcut trajectory is retrieved. Since the trajectory direction is in head-direction compass coordinates, navigation is accomplished by tracking the firing of head-direction cells that are tuned to the heading angle. Section 1 of the manuscript describes the properties of accumulating head-direction cells. It then shows how accumulating head-direction cells can store local vectors and perform vector arithmetic to perform path-integration-based homing. Section 2 describes the construction and use of the shortcut matrix for computing direct paths between any pair of locations that have been registered in the shortcut matrix. In the discussion, we analyze the advantages of heading-based navigation over map-based navigation. Finally, we survey behavioral evidence that nonhippocampal, heading-based navigation is used in small mammals and humans. Copyright 2008 Wiley-Liss, Inc.

Navigating oceans and cultures: Polynesian and European navigation systems in the late eighteenth century

NASA Astrophysics Data System (ADS)

Walker, M.

2012-05-01

Significant differences in the rotation of the celestial dome between the tropical and temperate zones did not stop the peoples of either the tropical Pacific or temperate Europe from using geocentric astronomy to guide exploration of the oceans. Although the differences in the night sky contributed to differences between the Pacific Island and European systems for navigation at sea, the two navigation systems exhibit substantial similarities. Both systems define positions on the surface of the Earth using two coordinates that vary at right angles to each other and use stars, and to a lesser extent the sun, to determine directions. This essay explores similarities and differences in the use of geocentric astronomy for navigation at sea by the peoples of Polynesia and Europe in the late eighteenth century. Captain Cook's orders to discover the unknown southern continent after observing the transit of Venus combined with differences in language and culture to obscure the deeper similarities between the navigation systems used by Cook and the Polynesians. Although it was a further 200 years before anthropologists studied Pacific navigation, collaborations in voyaging with communities in Oceania demonstrated the effectiveness of Pacific navigation systems, revived interest in traditional voyaging in island communities around the Pacific, and potentially open the way for further collaborations in other areas.

Does self-compassion mitigate the relationship between burnout and barriers to compassion? A cross-sectional quantitative study of 799 nurses.

PubMed

Dev, Vinayak; Fernando, Antonio T; Lim, Anecita Gigi; Consedine, Nathan S

2018-05-01

Burnout has numerous negative consequences for nurses, potentially impairing their ability to deliver compassionate patient care. However, the association between burnout and compassion and, more specifically, barriers to compassion in medicine is unclear. This article evaluates the associations between burnout and barriers to compassion and examines whether dispositional self-compassion might mitigate this association. Consistent with prior work, the authors expected greater burnout to predict greater barriers to compassion. We also expected self-compassion - the ability to be kind to the self during times of distress - to weaken the association between burnout and barriers to compassion among nurses. Registered nurses working in New Zealand medical contexts were recruited using non-random convenience sampling. Following consent, 799 valid participants completed a cross-sectional survey including the Copenhagen Burnout Inventory, the Barriers to Physician Compassion scale, and a measure of dispositional self-compassion. As expected, greater burnout predicted greater barriers to compassion while self-compassion predicted fewer barriers. However, self-compassion mitigated the association between burnout and burnout related barriers to compassion (but not other barriers). The interaction suggested that suggested that the association was stronger (rather than weaker) among those with greater self-compassion. Understanding the lack of compassion and the effects of burnout in patient care are priorities in health. This report extends evidence on the association between burnout and compassion-fatigue to show that burnout also predicts the experience of specific barriers to compassion. While self-compassion predicted lower burnout and barriers, it may not necessarily reduce the extent to which burnout contributes to the experience of barriers to compassion in medicine. Implications for understanding how burnout manifests in barriers to clinical compassion, interventions and professional training, and future directions in nursing are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

A heuristic model of enactive compassion.

PubMed

Halifax, Joan

2012-06-01

This article is an investigation of the possibility that compassion is not a discrete feature but an emergent and contingent process that is at its base enactive. Compassion must be primed through the cultivation of various factors. This article endeavors to identify interdependent components of compassion. This is particularly relevant for those in the end-of-life care professions, wherein compassion is an essential factor in the care of those suffering from a catastrophic illness or injury. The Halifax Model of Compassion is presented here as a new vision of compassion with particular relevance for the training of compassion in clinicians. Compassion is generally valued as a prosocial mental quality. The factors that foster compassion are not well understood, and the essential components of compassion have not been sufficiently delineated. Neuroscience research on compassion has only recently begun, and there is little clinical research on the role of compassion in end-of-life care. Compassion is in general seen as having two main components: the affective feeling of caring for one who is suffering and the motivation to relieve suffering. This definition of compassion might impose limitations and will, therefore, have consequences on how one trains compassion in clinicians and others. It is the author's premise that compassion is dispositionally enactive (the interactions between living organisms and their environments, i.e., the propensity toward perception-action in relation to one's surrounds), and it is a process that is contingent and emergent.

Combining sky and earth: desert ants (Melophorus bagoti) show weighted integration of celestial and terrestrial cues.

PubMed

Legge, Eric L G; Wystrach, Antoine; Spetch, Marcia L; Cheng, Ken

2014-12-01

Insects typically use celestial sources of directional information for path integration, and terrestrial panoramic information for view-based navigation. Here we set celestial and terrestrial sources of directional information in conflict for homing desert ants (Melophorus bagoti). In the first experiment, ants learned to navigate out of a round experimental arena with a distinctive artificial panorama. On crucial tests, we rotated the arena to create a conflict between the artificial panorama and celestial information. In a second experiment, ants at a feeder in their natural visually-cluttered habitat were displaced prior to their homing journey so that the dictates of path integration (feeder to nest direction) based on a celestial compass conflicted with the dictates of view-based navigation (release point to nest direction) based on the natural terrestrial panorama. In both experiments, ants generally headed in a direction intermediate to the dictates of celestial and terrestrial information. In the second experiment, the ants put more weight on the terrestrial cues when they provided better directional information. We conclude that desert ants weight and integrate the dictates of celestial and terrestrial information in determining their initial heading, even when the two directional cues are highly discrepant. © 2014. Published by The Company of Biologists Ltd.

[Effects of compassion satisfaction and social support in the relationship between compassion fatigue and burnout in hospital nurses].

PubMed

Yom, Young-Hee; Kim, Hyun-Jung

2012-12-01

The purpose of this study was to identify the effects of compassion satisfaction and social support in the relationship between compassion fatigue and burnout among hospital nurses. The participants were 430 nurses working in general hospitals. Data were collected with self-administrated questionnaires and analyzed by hierarchical multiple regression. (a) Compassion fatigue had a significant positive effect on burnout; (b) social support and compassion satisfaction had negative effects on burnout, and (c) social support and compassion satisfaction did not moderate the effects of compassion fatigue on burnout. These findings provide strong empirical evidence for the importance of compassion fatigue, compassion satisfaction and social support in explaining burnout of nurses. Also, it would be of great value to further define compassion fatigue and compassion satisfaction even though these concepts are not accepted in the realities of health care.

Behaviour of Talitrus saltator (Crustacea: Amphipoda) on a rehabilitated sandy beach on the European Atlantic Coast (Portugal)

NASA Astrophysics Data System (ADS)

Bessa, Filipa; Rossano, Claudia; Nourisson, Delphine; Gambineri, Simone; Marques, João Carlos; Scapini, Felicita

2013-01-01

Environmental and human controls are widely accepted as the main structuring forces of the macrofauna communities on sandy beaches. A population of the talitrid amphipod Talitrus saltator (Montagu, 1808) was investigated on an exposed sandy beach on the Atlantic coast of Portugal (Leirosa beach) to estimate orientation capabilities and endogenous rhythms in conditions of recent changes in the landscape (artificial reconstruction of the foredune) and beach morphodynamics (stabilization against erosion from the sea). We tested sun orientation of talitrids on the beach and recorded their locomotor activity rhythms under constant conditions in the laboratory. The orientation data were analysed with circular statistics and multiple regression models adapted to angular distributions, to highlight the main factors and variables influencing the variation of orientation. The talitrids used the sun compass, visual cues (landscape and sun visibility) to orient and the precision of orientation varied according to the tidal regime (rising or ebbing tides). A well-defined free-running rhythm (circadian with in addition a bimodal rhythmicity, likely tidal) was highlighted in this population. This showed a stable behavioural adaptation on a beach that has experienced a process of artificial stabilization of the dune through nourishment actions over a decade. Monitoring the conditions of such dynamic environments and the resilience capacity of the inhabiting macroinfauna is a main challenge for sandy beach ecologists.

Compassion fatigue among nurses working with older adults.

PubMed

Kolthoff, Kay L; Hickman, Susan E

Nurses who care for older patients are exposed to significant suffering and loss that can lead to the development of compassion fatigue and burnout. An exploratory descriptive study was conducted to assess compassion fatigue, burnout, and compassion satisfaction in a group of 42 nurses who worked on a geriatric medicine unit using the Professional Quality of Life (ProQOL) compassion satisfaction and compassion fatigue 5 scale. Nurses reported average levels of compassion fatigue, burnout, and compassion satisfaction. However, new nurses reported higher levels of compassion fatigue (p < .01) and burnout (p = .02) than experienced nurses. Findings suggest the need to purposely build a supportive environment that focuses on new nurses to reduce compassion fatigue and burnout while enhancing compassion satisfaction. Copyright © 2016 Elsevier Inc. All rights reserved.

Side-effects of a bad attitude: How GNSS spacecraft orientation errors affect solar radiation pressure modelling

NASA Astrophysics Data System (ADS)

Dilssner, Florian; Springer, Tim; Schönemann, Erik; Zandbergen, Rene; Enderle, Werner

2015-04-01

Solar radiation pressure (SRP) is the largest non-gravitational perturbation for Global Navigation Satellite System (GNSS) satellites, and can therefore have substantial impact on their orbital dynamics. Various SRP force models have been developed over the past 30 years for the purpose of precise orbit determination. They all rely upon the assumption that the satellites continuously maintain a Sun-Nadir pointing attitude with the navigation antenna boresight (body-fixed z-axis) pointing towards Earth center, and the solar panel rotation axis (body-fixed y-axis) being normal to the Sun direction. However, in reality, this is not perfectly the case. Reasons for a non-nominal spacecraft attitude may be eclipse maneuvers, commanded attitude biases and Sun/horizon sensor measurement errors, for example due to mounting misalignment or incorrectly calibrated sensor electronics. In this work the effect of GNSS spacecraft orientation errors on SRP modelling is investigated. Simplified mathematical functions describing the SRP force acting on the solar arrays in the presence of yaw-, pitch- and roll-biases are derived. Special attention is paid to the yaw-bias and its relationship to the SRP dynamics, particular in direction of the spacecraft y-axis ("y-bias force"). Analytical and experimental results gathered from orbit and attitude analyses of GPS Block II/IIA/IIF satellites demonstrate how sensitive the SRP coefficients are to changes in yaw.

Clementine Observes the Moon, Solar Corona, and Venus

NASA Technical Reports Server (NTRS)

1997-01-01

In 1994, during its flight, the Clementine spacecraft returned images of the Moon. In addition to the geologic mapping cameras, the Clementine spacecraft also carried two Star Tracker cameras for navigation. These lightweight (0.3 kg) cameras kept the spacecraft on track by constantly observing the positions of stars, reminiscent of the age-old seafaring tradition of sextant/star navigation. These navigation cameras were also to take some spectacular wide angle images of the Moon.

In this picture the Moon is seen illuminated solely by light reflected from the Earth--Earthshine! The bright glow on the lunar horizon is caused by light from the solar corona; the sun is just behind the lunar limb. Caught in this image is the planet Venus at the top of the frame.

Relationships between nurses' empathy, self-compassion and dimensions of professional quality of life: A cross-sectional study.

PubMed

Duarte, Joana; Pinto-Gouveia, José; Cruz, Bárbara

2016-08-01

Job stress and burnout are common among healthcare professionals, and nurses in particular. In addition to the heavy workload and lack of recourses, nurses are also confronted with emotionally intense situations associated with illness and suffering, which require empathic abilities. Although empathy is one of the core values in nursing, if not properly balanced it can also have detrimental consequences, such as compassion fatigue. Self-compassion, on the other hand, has been shown to be a protective factor for a wide range of well-being indicators and has been associated with compassion for others. The main goal of this study was to explore how empathy and self-compassion related to professional quality of life (compassion satisfaction, compassion fatigue and burnout). In addition, we wanted to test whether self-compassion may be a protective factor for the impact of empathy on compassion fatigue. Using a cross-sectional design, 280 registered nurses from public hospitals in Portugal's north and center region were surveyed. Professional quality of life (Professional Quality of Life), empathy (Interpersonal Reactivity Index) and self-compassion (Self-compassion Scale) were measured using validated self-report measures. Correlations and regression analyses showed that empathy and self-compassion predicted the three aspects of professional quality of life. Empathic concern was positively associated with compassion satisfaction as well as with compassion fatigue. Mediation models suggested that the negative components of self-compassion explain some of these effects, and self-kindness and common humanity were significant moderators. The same results were found for the association between personal distress and compassion fatigue. High levels of affective empathy may be a risk factor for compassion fatigue, whereas self-compassion might be protective. Teaching self-compassion and self-care skills may be an important feature in interventions that aim to reduce burnout and compassion fatigue. Copyright © 2016 Elsevier Ltd. All rights reserved.

Factors that influence the development of compassion fatigue, burnout, and compassion satisfaction in emergency department nurses.

PubMed

Hunsaker, Stacie; Chen, Hsiu-Chin; Maughan, Dale; Heaston, Sondra

2015-03-01

The purpose of this study was twofold: (a) to determine the prevalence of compassion satisfaction, compassion fatigue, and burnout in emergency department nurses throughout the United States and (b) to examine which demographic and work-related components affect the development of compassion satisfaction, compassion fatigue, and burnout in this nursing specialty. This was a nonexperimental, descriptive, and predictive study using a self-administered survey. Survey packets including a demographic questionnaire and the Professional Quality of Life Scale version 5 (ProQOL 5) were mailed to 1,000 selected emergency nurses throughout the United States. The ProQOL 5 scale was used to measure the prevalence of compassion satisfaction, compassion fatigue, and burnout among emergency department nurses. Multiple regression using stepwise solution was employed to determine which variables of demographics and work-related characteristics predicted the prevalence of compassion satisfaction, compassion fatigue, and burnout. The α level was set at .05 for statistical significance. The results revealed overall low to average levels of compassion fatigue and burnout and generally average to high levels of compassion satisfaction among this group of emergency department nurses. The low level of manager support was a significant predictor of higher levels of burnout and compassion fatigue among emergency department nurses, while a high level of manager support contributed to a higher level of compassion satisfaction. The results may serve to help distinguish elements in emergency department nurses' work and life that are related to compassion satisfaction and may identify factors associated with higher levels of compassion fatigue and burnout. Improving recognition and awareness of compassion satisfaction, compassion fatigue, and burnout among emergency department nurses may prevent emotional exhaustion and help identify interventions that will help nurses remain empathetic and compassionate professionals. © 2015 Sigma Theta Tau International.

Compassion fatigue, burnout, and compassion satisfaction among Colorado child protection workers.

PubMed

Conrad, David; Kellar-Guenther, Yvonne

2006-10-01

The goal of this study was to understand better the risk of compassion fatigue (the trauma suffered by the helping professional) and burnout (emotional exhaustion, depersonalization, and reduced sense of personal accomplishment), and the potential for compassion satisfaction (the fulfillment from helping others and positive collegial relationships) among Colorado county child protection staff using the Compassion Satisfaction/Fatigue Self-Test [Figley, C. R., & Stamm, B. H. (1996). Psychometric review of Compassion Fatigue Self-Test. In B. H. Stamm (Ed.), Measurement of stress, trauma, and adaptation (pp. 127-130). Lutherville, MD: Sidran Press]. An additional goal was to test the relationship of these three constructs to each other. A self-report instrument developed by Stamm and Figley was used to measure the risk of compassion fatigue and burnout and the potential for compassion satisfaction among 363 child protection staff participating in a secondary trauma training seminar. Participants were significantly more likely to have high risk of compassion fatigue, extremely low risk of burnout, and good potential for compassion satisfaction. Participants with high compassion satisfaction had lower levels of compassion fatigue (p=.000; mean=35.73 high compassion satisfaction group, mean=43.56 low group) and lower levels of burnout (p=.000; mean=32.99 high compassion satisfaction group, mean=41.69 low group). Approximately 50% of Colorado county child protection staff suffered from "high" or "very high" levels of compassion fatigue. The risk of burnout was considerably lower. More than 70% of staff expressed a "high" or "good" potential for compassion satisfaction. We believe compassion satisfaction may help mitigate the effects of burnout.

Understanding the roles of self-esteem, self-compassion, and fear of self-compassion in eating disorder pathology: an examination of female students and eating disorder patients.

PubMed

Kelly, Allison C; Vimalakanthan, Kiruthiha; Carter, Jacqueline C

2014-08-01

The present study examined the relative contributions of self-compassion, fear of self-compassion, and self-esteem in eating disorder pathology. One-hundred and fifty-five female undergraduate students and 97 females entering eating disorder treatment completed the Self-Compassion Scale, Fears of Compassion Scale, Rosenberg Self-Esteem Inventory, and Eating Disorder Examination Questionnaire. T-tests revealed that the patient group had lower mean self-compassion and higher mean fear of self-compassion than the student group. When controlling for self-esteem, high fear of self-compassion emerged as the strongest predictor of eating disorder pathology in the patient group, whereas low self-compassion was the strongest predictor in the student group. These preliminary results suggest that targeting fear of self-compassion may be important when intervening with individuals suffering from an eating disorder, whereas building self-compassion may be a valuable approach for eating disorder prevention. Copyright © 2014 Elsevier Ltd. All rights reserved.

Can Self-Compassion Promote Healthcare Provider Well-Being and Compassionate Care to Others? Results of a Systematic Review.

PubMed

Sinclair, Shane; Kondejewski, Jane; Raffin-Bouchal, Shelley; King-Shier, Kathryn M; Singh, Pavneet

2017-07-01

This meta-narrative review, conducted according to the RAMESES (Realist And Meta-narrative Evidence Syntheses: Evolving Standards) standards, critically examines the construct of self-compassion to determine if it is an accurate target variable to mitigate work-related stress and promote compassionate caregiving in healthcare providers. PubMed, Medline, CINAHL, PsycINFO, and Web of Science databases were searched. Studies were coded as referring to: (1) conceptualisation of self-compassion; (2) measures of self-compassion; (3) self-compassion and affect; and (4) self-compassion interventions. A narrative approach was used to evaluate self-compassion as a paradigm. Sixty-nine studies were included. The construct of self-compassion in healthcare has significant limitations. Self-compassion has been related to the definition of compassion, but includes limited facets of compassion and adds elements of uncompassionate behavior. Empirical studies use the Self-Compassion Scale, which is criticised for its psychometric and theoretical validity. Therapeutic interventions purported to cultivate self-compassion may have a broader effect on general affective states. An alleged outcome of self-compassion is compassionate care; however, we found no studies that included patient reports on this primary outcome. We critically examine and delineate self-compassion in healthcare providers as a composite of common facets of self-care, healthy self-attitude, and self-awareness rather than a construct in and of itself. © 2017 The International Association of Applied Psychology.

Mysterious Roving Rocks of Racetrack Playa

NASA Image and Video Library

2017-12-08

A small level is used to see if the trail is tilted upward or downward. In most cases where a rock has moved, the trail is tilted very slightly uphill, but the interns don't think this has a noticeable effect on the movement. The compass is included for scale. Photo credit: NASA/GSFC/Leva McIntire/LPSA intern To read a feature story on the Racetrack Playa go to: www.nasa.gov/topics/earth/features/roving-rocks.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Environmental statement for Applications Technology Satellite program

NASA Technical Reports Server (NTRS)

1971-01-01

The experiments, environmental impact, and applications of data collected by ATS are discussed. Data cover communications, navigation, meteorology, data collection (including data from small unattended remote stations such as buoys, seismology and hydrology monitors, etc.), geodesy, and scientific experiments to define the environment at synchronous orbit, and to monitor emissions from the sun.

The development of fears of compassion scale Japanese version.

PubMed

Asano, Kenichi; Tsuchiya, Masao; Ishimura, Ikuo; Lin, Shuzhen; Matsumoto, Yuki; Miyata, Haruko; Kotera, Yasuhiro; Shimizu, Eiji; Gilbert, Paul

2017-01-01

Cultivation of compassion is a useful way to treat mental problems, but some individuals show resistance. Fears of compassion can be an obstacle for clinicians when providing psychotherapy, and for clients when engaging in interpersonal relationships. Despite its importance, a Japanese version of fears of compassion scales (for others, from others, and for self) has not yet been developed. This study developed a Japanese version of the Fears of Compassion Scales and tested its reliability and validity. This study used a cross-sectional design, and a self-report procedure for collecting data. A total of 485 students (121 males and 364 females) answered self-report questionnaires, including the draft Fears of Compassion Scales-Japanese version. There were distinctive factor structures for fear of compassion from others, and for self. The fear of compassion from others scale consisted of concern about compassion from others and avoidance of compassion from others. All scales had good internal consistency, test-retest reliability, face validity, and construct validity. Discrimination and difficulty were also calculated. These results indicate that the Fears of Compassion Scales-Japanese version is a well-constructed and useful measure to assess fears of compassion and the existence of cultural differences in fears of compassion.

Self-compassion training for binge eating disorder: a pilot randomized controlled trial.

PubMed

Kelly, Allison C; Carter, Jacqueline C

2015-09-01

The present pilot study sought to compare a compassion-focused therapy (CFT)-based self-help intervention for binge eating disorder (BED) to a behaviourally based intervention. Forty-one individuals with BED were randomly assigned to 3 weeks of food planning plus self-compassion exercises; food planning plus behavioural strategies; or a wait-list control condition. Participants completed weekly measures of binge eating and self-compassion; pre- and post-intervention measures of eating disorder pathology and depressive symptoms; and a baseline measure assessing fear of self-compassion. Results showed that: (1) perceived credibility, expectancy, and compliance did not differ between the two interventions; (2) both interventions reduced weekly binge days more than the control condition; (3) the self-compassion intervention reduced global eating disorder pathology, eating concerns, and weight concerns more than the other conditions; (4) the self-compassion intervention increased self-compassion more than the other conditions; and (5) participants low in fear of self-compassion derived significantly more benefits from the self-compassion intervention than those high in fear of self-compassion. Findings offer preliminary support for the usefulness of CFT-based interventions for BED sufferers. Results also suggest that for individuals to benefit from self-compassion training, assessing and lowering fear of self-compassion will be crucial. Individuals with BED perceive self-compassion training self-help interventions, derived from CFT, to be as credible and as likely to help as behaviourally based interventions. The cultivation of self-compassion may be an effective approach for reducing binge eating, and eating, and weight concerns in individuals with BED. Teaching individuals with BED CFT-based self-help exercises may increase their self-compassion levels over a short period of time. It may be important for clinicians to assess and target clients' fear of self-compassion for clients to benefit from self-compassion training interventions. © 2014 The British Psychological Society.

How do they make it look so easy? The expert orienteer's cognitive advantage.

PubMed

Eccles, David W; Arsal, Guler

2015-01-01

Expertise in sport can appear so extraordinary that it is difficult to imagine how "normal" individuals may achieve it. However, in this review, we show that experts in the sport of orienteering, which requires on-foot navigation using map and compass through wild terrain, can make the difficult look easy because they have developed a cognitive advantage. Specifically, they have acquired knowledge of cognitive and behavioural strategies that allow them to circumvent natural limitations on attention. Cognitive strategies include avoiding peaks of demand on attention by distributing the processing of map information over time and reducing the need to attend to the map by simplifying the navigation required to complete a race. Behavioural strategies include reducing the visual search required of the map by physically arranging and rearranging the map display during races. It is concluded that expertise in orienteering can be partly attributed to the circumvention of natural limitations on attention achieved via the employment of acquired cognitive and behavioural strategies. Thus, superior performance in sport may not be the possession of only a privileged few; it may be available to all aspiring athletes.

Going with the flow: a brief history of the study of the honeybee's navigational 'odometer'.

PubMed

Srinivasan, Mandyam V

2014-06-01

Honeybees navigate to a food source using a sky-based compass to determine their travel direction, and an odometer to register how far they have travelled. The past 20 years have seen a renewed interest in understanding the nature of the odometer. Early work, pioneered by von Frisch and colleagues, hypothesized that travel distance is measured in terms of the energy that is consumed during the journey. More recent studies suggest that visual cues play a role as well. Specifically, bees appear to gauge travel distance by sensing the extent to which the image of the environment moves in the eye during the journey from the hive to the food source. Most of the evidence indicates that travel distance is measured during the outbound journey. Accumulation of odometric errors is restricted by resetting the odometer every time a prominent landmark is passed. When making detours around large obstacles, the odometer registers the total distance of the path that is flown to the destination, and not the "bee-line" distance. Finally, recent studies are revealing that bees can perform odometry in three dimensions.

COMPASS Final Report: Lunar Communications Terminal (LCT)

NASA Technical Reports Server (NTRS)

Oleson, Steven R.; McGuire, Melissa L.

2010-01-01

The Lunar Communications Terminal (LCT) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session designed a terminal to provide communications between lunar South Pole assets, communications relay to/from these assets through an orbiting Lunar Relay Satellite (LRS) and navigation support. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The Terminal consists of a pallet containing the communications and avionics equipment, surrounded by the thermal control system (radiator), an attached, deployable 10-m tower, upon which were mounted locally broadcasting and receiving modems and a deployable 1 m diameter Ka/S band dish which provides relay communications with the lunar relay satellites and, as a backup, Earth when it is in view. All power was assumed to come from the lunar outpost Habitat. Three LCT design options were explored: a stand-alone LCT servicing the manned outpost, an integrated LCT (into the Habitat or Lunar Lander), and a mini-LCT which provides a reduced level of communication for primarily robotic areas dealing as in situ resource utilization (ISRU) and remote science. Where possible all the designs assumed single fault tolerance. Significant mass savings were found when integrating the LCT into the Habitat or Lander but increases in costs occurred depending upon the level of man rating required for such designs.

Pediatric novice nurses: examining compassion fatigue as a mediator between stress exposure and compassion satisfaction, burnout, and job satisfaction.

PubMed

Meyer, Rika M L; Li, Angela; Klaristenfeld, Jessica; Gold, Jeffrey I

2015-01-01

We investigated whether compassion fatigue mediated associations between nurse stress exposure and job satisfaction, compassion satisfaction, and burnout, controlling for pre-existing stress. The Life Events Checklist was administered to 251 novice pediatric nurses at the start of the nurse residency program (baseline) and 3 months after to assess pre-existing and current stress exposure. Compassion satisfaction, compassion fatigue, and burnout were assessed 3 months after baseline and job satisfaction 6 months after. Stress exposure significantly predicted lower compassion satisfaction and more burnout. Compassion fatigue partially mediated these associations. Results demonstrate a need for hospitals to prevent compassion fatigue in healthcare providers. Copyright © 2015 Elsevier Inc. All rights reserved.

Corruption of radio metric Doppler due to solar plasma dynamics: S/X dual-frequency Doppler calibration for these effects

NASA Technical Reports Server (NTRS)

Winn, F. B.; Reinbold, S. R.; Yip, K. W.; Koch, R. E.; Lubeley, A.

1975-01-01

Doppler data from Mariner 6, 7, 9, and 10 and Pioneer 10 and 11 were discussed and the rms noise level for various sun-earth-probe angles were shown. The noise levels of both S- and X-band Doppler data for sun-earth-probe angles smaller than 20 deg were observed to be orders of magnitude greater than nominal. Such solar plasma-related Doppler degradation reduced the Mariner 10-Mercury 11 encounter navigation accuracy by nearly a factor of 10. Furthermore, this degradation was shown to be indirectly related to plasma dynamics and not a direct measure of the dynamics.

The development of fears of compassion scale Japanese version

PubMed Central

Asano, Kenichi; Tsuchiya, Masao; Ishimura, Ikuo; Lin, Shuzhen; Matsumoto, Yuki; Miyata, Haruko; Kotera, Yasuhiro; Shimizu, Eiji; Gilbert, Paul

2017-01-01

Objectives Cultivation of compassion is a useful way to treat mental problems, but some individuals show resistance. Fears of compassion can be an obstacle for clinicians when providing psychotherapy, and for clients when engaging in interpersonal relationships. Despite its importance, a Japanese version of fears of compassion scales (for others, from others, and for self) has not yet been developed. This study developed a Japanese version of the Fears of Compassion Scales and tested its reliability and validity. Design This study used a cross-sectional design, and a self-report procedure for collecting data. Methods A total of 485 students (121 males and 364 females) answered self-report questionnaires, including the draft Fears of Compassion Scales—Japanese version. Results There were distinctive factor structures for fear of compassion from others, and for self. The fear of compassion from others scale consisted of concern about compassion from others and avoidance of compassion from others. All scales had good internal consistency, test-retest reliability, face validity, and construct validity. Discrimination and difficulty were also calculated. Conclusions These results indicate that the Fears of Compassion Scales—Japanese version is a well-constructed and useful measure to assess fears of compassion and the existence of cultural differences in fears of compassion. PMID:29023461

Building compassion literacy: Enabling care in primary health care nursing.

PubMed

Burridge, Letitia Helen; Winch, Sarah; Kay, Margaret; Henderson, Amanda

This paper introduces the concept of compassion literacy and discusses its place in nursing within the general practice setting. Compassion literacy is a valuable competency for sustaining the delivery of high quality care. Being compassion literate enables practice nurses to provide compassionate care to their patients and to recognise factors that may constrain this. A compassion literate practice nurse may be more protected from compassion fatigue and its negative consequences. Understanding how to enable self-compassion and how to support the delivery of compassionate care within the primary care team can enhance the care experienced by the patient while improving the positive engagement and satisfaction of the health professionals. The capacity to deliver compassionate care can be depleted by the day-to-day demands of the clinical setting. Compassion literacy enables the replenishing of compassion, but the development of compassion literacy can be curtailed by personal and workplace barriers. This paper articulates why compassion literacy should be an integral aspect of practice nursing and considers strategies for enabling compassion literacy to develop and thrive within the workplace environment. Compassion literacy is also a valuable opportunity for practice nurses to demonstrate their key role within the multidisciplinary team of general practice, directly enhancing the quality of the care delivered.

Clementine Observes the Moon, Solar Corona, and Venus

NASA Image and Video Library

1999-06-12

In 1994, during its flight, NASA's Clementine spacecraft returned images of the Moon. In addition to the geologic mapping cameras, the Clementine spacecraft also carried two Star Tracker cameras for navigation. These lightweight (0.3 kg) cameras kept the spacecraft on track by constantly observing the positions of stars, reminiscent of the age-old seafaring tradition of sextant/star navigation. These navigation cameras were also to take some spectacular wide angle images of the Moon. In this picture the Moon is seen illuminated solely by light reflected from the Earth--Earthshine! The bright glow on the lunar horizon is caused by light from the solar corona; the sun is just behind the lunar limb. Caught in this image is the planet Venus at the top of the frame. http://photojournal.jpl.nasa.gov/catalog/PIA00434

A study of the relationship between self-care, compassion satisfaction, compassion fatigue, and burnout among hospice professionals.

PubMed

Alkema, Karen; Linton, Jeremy M; Davies, Randall

2008-01-01

Hospice care professionals (HCPs) experience a large number of stressors in their work settings. The purpose of this study was to investigate the relationship between self-care, compassion fatigue, burnout, and compassion satisfaction among HCPs. Thirty-seven HCPs were surveyed regarding their levels of compassion satisfaction, compassion fatigue, and burnout. Respondents also reported the types of self-care activities in which they took part. Results indicated a relationship between self-care strategies and lower levels of burnout and compassion fatigue, and higher levels of compassion satisfaction. Several suggestions are offered for continued research and practice in the hospice care field.

Aircraft compass characteristics

NASA Technical Reports Server (NTRS)

Peterson, John B; Smith, Clyde W

1937-01-01

A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.

Helping the self help others: self-affirmation increases self-compassion and pro-social behaviors

PubMed Central

Lindsay, Emily K.; Creswell, J. David

2014-01-01

Reflecting on an important personal value in a self-affirmation activity has been shown to improve psychological functioning in a broad range of studies, but the underlying mechanisms for these self-affirmation effects are unknown. Here we provide an initial test of a novel self-compassion account of self-affirmation in two experimental studies. Study 1 shows that an experimental manipulation of self-affirmation (3-min of writing about an important personal value vs. writing about an unimportant value) increases feelings of self-compassion, and these feelings in turn mobilize more pro-social behaviors to a laboratory shelf-collapse incident. Study 2 tests and extends these effects by evaluating whether self-affirmation increases feelings of compassion toward the self (consistent with the self-compassion account) or increases feelings of compassion toward others (an alternative other-directed compassion account), using a validated storytelling behavioral task. Consistent with a self-compassion account, Study 2 demonstrates the predicted self-affirmation by video condition interaction, indicating that self-affirmation participants had greater feelings of self-compassion in response to watching their own storytelling performance (self-compassion) compared to watching a peer’s storytelling performance (other-directed compassion). Further, pre-existing levels of trait self-compassion moderated this effect, such that self-affirmation increased self-compassionate responses the most in participants low in trait self-compassion. This work suggests that self-compassion may be a promising mechanism for self-affirmation effects, and that self-compassionate feelings can mobilize pro-social behaviors. PMID:24860534

Helping the self help others: self-affirmation increases self-compassion and pro-social behaviors.

PubMed

Lindsay, Emily K; Creswell, J David

2014-01-01

Reflecting on an important personal value in a self-affirmation activity has been shown to improve psychological functioning in a broad range of studies, but the underlying mechanisms for these self-affirmation effects are unknown. Here we provide an initial test of a novel self-compassion account of self-affirmation in two experimental studies. Study 1 shows that an experimental manipulation of self-affirmation (3-min of writing about an important personal value vs. writing about an unimportant value) increases feelings of self-compassion, and these feelings in turn mobilize more pro-social behaviors to a laboratory shelf-collapse incident. Study 2 tests and extends these effects by evaluating whether self-affirmation increases feelings of compassion toward the self (consistent with the self-compassion account) or increases feelings of compassion toward others (an alternative other-directed compassion account), using a validated storytelling behavioral task. Consistent with a self-compassion account, Study 2 demonstrates the predicted self-affirmation by video condition interaction, indicating that self-affirmation participants had greater feelings of self-compassion in response to watching their own storytelling performance (self-compassion) compared to watching a peer's storytelling performance (other-directed compassion). Further, pre-existing levels of trait self-compassion moderated this effect, such that self-affirmation increased self-compassionate responses the most in participants low in trait self-compassion. This work suggests that self-compassion may be a promising mechanism for self-affirmation effects, and that self-compassionate feelings can mobilize pro-social behaviors.

An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators

PubMed Central

Mouritsen, Henrik; Derbyshire, Rachael; Stalleicken, Julia; Mouritsen, Ole Ø.; Frost, Barrie J.; Norris, D. Ryan

2013-01-01

Monarch butterflies (Danaus plexippus) breeding in eastern North America are famous for their annual fall migration to their overwintering grounds in Mexico. However, the mechanisms they use to successfully reach these sites remain poorly understood. Here, we test whether monarchs are true navigators who can determine their location relative to their final destination using both a “compass” and a “map”. Using flight simulators, we recorded the orientation of wild-caught monarchs in southwestern Ontario and found that individuals generally flew in a southwest direction toward the wintering grounds. When displaced 2,500 km to the west, the same individuals continued to fly in a general southwest direction, suggesting that monarchs use a simple vector-navigation strategy (i.e., use a specific compass bearing without compensating for displacement). Using over 5 decades of field data, we also show that the directional concentration and the angular SD of recoveries from tagged monarchs largely conformed to two mathematical models describing the directional distribution of migrants expected under a vector-navigation strategy. A third analysis of tagged recoveries shows that the increasing directionality of migration from north to south is largely because of the presence of geographic barriers that guide individuals toward overwintering sites. Our work suggests that monarchs breeding in eastern North America likely combine simple orientation mechanisms with geographic features that funnel them toward Mexican overwintering sites, a remarkable achievement considering that these butterflies weigh less than a gram and travel thousands of kilometers to a site they have never seen. PMID:23569228

Comparison of helmet-mounted display designs in support of wayfinding

NASA Astrophysics Data System (ADS)

Kumagai, Jason K.; Massel, Lisa; Tack, David; Bossi, Linda

2003-09-01

The Canadian Soldier Information Requirements Technology Demonstration (SIREQ TD) soldier modernization research and development program has conducted experiments to help determine the types and amount of information needed to support wayfinding across a range of terrain environments, the most effective display modality for providing the information (visual, auditory or tactile) that will minimize conflict with other infantry tasks, and to optimize interface design. In this study, seven different visual helmet-mounted display (HMD) designs were developed based on soldier feedback from previous studies. The displays and an in-service compass condition were contrasted to investigate how the visual HMD interfaces influenced navigation performance. Displays varied with respect to their information content, frame of reference, point of view, and display features. Twelve male infantry soldiers used all eight experimental conditions to locate bearings to waypoints. From a constant location, participants were required to face waypoints presented at offset bearings of 25, 65, and 120 degrees. Performance measures included time to identify waypoints, accuracy, and head misdirection errors. Subjective measures of performance included ratings of ease of use, acceptance for land navigation, and mental demand. Comments were collected to identify likes, dislikes and possible improvements required for HMDs. Results underlined the potential performance enhancement of GPS-based navigation with HMDs, the requirement for explicit directional information, the desirability of both analog and digital information, the performance benefits of an egocentric frame of reference, the merit of a forward field of view, and the desirability of a guide to help landmark. Implications for the information requirements and human factors design of HMDs for land-based navigational tasks are discussed.

Daytime Celestial Navigation for the Novice

ERIC Educational Resources Information Center

Sadler, Philip M.; Night, Christopher

2010-01-01

What kinds of astronomical lab activities can high school and college astronomy students carry out easily in daytime? The most impressive is the determination of latitude and longitude from observations of the Sun. The "shooting of a noon sight" and its "reduction to a position" grew to become a daily practice at the start of the 19th century…

Environmental and Water Quality Operational Studies. Bibliography of Effects of Commercial Navigation Traffic in Large Waterways

DTIC Science & Technology

1987-04-01

Largemouth Bass and Green Sun- fish," Technical Paper 20 of the U. S. Bureau of Sport Fisheries and Wildlife. Washington, DC. Helvig, P. C. 1966. "An...as a Chronobiological Phenomena in, ,Running Water Ecosystems," Annual Review of Ecology and Systematics, Vol 5. pp 309-323. North Star Research

A synoptic study of Sudden Phase Anomalies (SPA's) effecting VLF navigation and timing

NASA Technical Reports Server (NTRS)

Swanson, E. R.; Kugel, C. P.

1973-01-01

Sudden phase anomalies (SPA's) observed on VLF recordings are related to sudden ionospheric disturbances due to solar flares. Results are presented for SPA statistics on 500 events observed in New York during the ten year period 1961 to 1970. Signals were at 10.2kHz and 13.6kHz emitted from the OMEGA transmitters in Hawaii and Trinidad. A relationship between SPA frequency and sun spot number was observed. For sun spot number near 85, about one SPA per day will be observed somewhere in the world. SPA activity nearly vanishes during periods of low sun spot number. During years of high solar activity, phase perturbations observed near noon are dominated by SPA effects beyond the 95th percentile. The SPA's can be represented by a rapid phase run-off which is approximately linear in time, peaking in about 6 minutes, and followed by a linear recovery. Typical duration is 49 minutes.

Emu Dreaming: An Introduction to Australian Aboriginal Astronomy

NASA Astrophysics Data System (ADS)

Norris, Ray P.; Norris, Cilla M.

2009-07-01

Each of the 400 different Aboriginal cultures in Australia has a distinct mythology, ceremonies, and art forms, some of which have a strong astronomical component. Many share common traditions such as the "emu in the sky" constellation of dark clouds, and stories about the Sun, Moon , Orion, and the Pleiades. Several use the rising and setting of particular stars to indicate the time to harvest a food source, and some link the Sun and Moon to tides, and even explain eclipses as a conjunction of the Sun and Moon. Thse traditions reveal a depth and complexity of Aboriginal cultures which are not widely appreciated by outsiders. This book explores the wonderful mystical Aboriginal astronomical stories and traditions, and the way in which these are used for practical applications such as navigation and harvesting. It also describes the journey of exploration which is opening Western eyes to this treasury of ancient Aboriginal knowledge.

Descriptive study of burnout, compassion fatigue and compassion satisfaction in undergraduate nursing students at a tertiary education institution in KwaZulu-Natal.

PubMed

Mathias, Christina T; Wentzel, Dorien L

2017-09-22

Studies have investigated burnout and compassion fatigue among nurses and effects in the nursing profession. However, there are limited investigations of burnout and compassion fatigue among undergraduate nursing students in South Africa, as nursing students may experience distressful situations during their nursing education course, which may have an impact during their training and in their profession as they graduate. The purpose of this descriptive study was to describe compassion satisfaction, compassion fatigue and burnout among undergraduate nursing students at a tertiary nursing institution. A quantitative descriptive study was conducted to describe compassion satisfaction, compassion fatigue and burnout among undergraduate nursing students at a tertiary nursing institution in KwaZulu-Natal. Convenience sampling was used. Sixty-seven undergraduate students (26 third-year and 41 fourth-year nursing students) took the self-test Professional Quality of Life Scale (ProQOL). The study results indicate that undergraduate students experienced average levels of compassion fatigue, burnout and compassion satisfaction. As shown in the study, some of the undergraduate students are experiencing compassion fatigue and burnout, associated with relieving suffering of others. Therefore, knowledge of compassion fatigue and burnout and the coping strategies should be part of nursing training.

Understanding Compassion Satisfaction, Compassion Fatigue and Burnout: a survey of the hospice palliative care workforce.

PubMed

Slocum-Gori, Suzanne; Hemsworth, David; Chan, Winnie W Y; Carson, Anna; Kazanjian, Arminee

2013-02-01

Despite the increasingly crucial role of the healthcare workforce and volunteers working in hospice and palliative care (HPC), very little is known about factors that promote or limit the positive outcomes associated with practicing compassion. The purpose of this study was to: 1) understand the complex relationships among Compassion Satisfaction, Compassion Fatigue and Burnout within the hospice and palliative care workforce and 2) explore how key practice characteristics - practice status, professional affiliation, and principal institution - interact with the measured constructs of Compassion Satisfaction, Compassion Fatigue and Burnout. Self-reported measures of Compassion Satisfaction, Compassion Fatigue and Burnout, using validated scales, as well as questions to describe socio-demographic profiles and key practice characteristics were obtained. A national survey of HPC workers, comprising clinical, administrative, allied health workers and volunteers, was completed. Respondents from hospital, community-based and care homes informed the results of our study (n = 630). Our results indicate a significant negative correlation between Compassion Satisfaction and Burnout (r = -0.531, p < 0.001) and between Compassion Satisfaction and Compassion Fatigue (r = -0.208, p < 0.001), and a significant positive correlation between Burnout and Compassion Fatigue (r = 0.532, p < 0.001). Variations in self-reported levels of the above constructs were noted by key practice characteristics. Levels of all three constructs are significantly, but differentially, affected by type of service provided, principal institution, practice status and professional affiliation. Results indicate that health care systems could increase the prevalence of Compassion Satisfaction through both policy and institutional level programs to support HPC professionals in their jurisdictions.

Role of compassion competence among clinical nurses in professional quality of life.

PubMed

Lee, Y; Seomun, G

2016-09-01

The study aimed to explore measurable compassion competence among nurses and to examine the relationships between nurses' compassion competence and levels of compassion satisfaction, compassion fatigue and secondary traumatic stress. Compassion is a vital asset in the nursing profession. It is necessary to explore whether compassion competence is a factor influencing professional quality of life. This study utilized a multicenter descriptive cross-sectional survey. Data were collected from 680 nurses. Professional quality of life based on nurses' general characteristics showed a significant difference in the subjects' age, marital status, education, and total clinical experience. In addition, compassion competence had a significant positive correlation with compassion satisfaction and STS, whereas it had a significant negative correlation with burnout. Compassion competence was a factor influencing compassion satisfaction and burnout in professional quality of life. Our study included nurses with at least 1 year of clinical experience in a single cultural area, which limits its widespread applicability. To improve generalizability, future studies should include clinical nurses of various races, working in diverse cultural areas and with various levels of experience (including entry-level nurses and nursing students). Compassion competence of clinical nurses was a predictive factor for professional quality of life. Hospital administrators, nurse leaders and policy makers should develop and adopt nurse-retaining strategies that focus on improving nurses' compassion competence in order to reduce their burnout. We recommend the development of educational programmes to improve nurses' compassion competence and thereby enhance their professional quality of life. © 2016 International Council of Nurses.

Compassion Fatigue: An Application of the Concept to Informal Caregivers of Family Members with Dementia

PubMed Central

Day, Jennifer R.; Anderson, Ruth A.

2011-01-01

Introduction. Compassion fatigue is a concept used with increasing frequency in the nursing literature. The objective of this paper is to identify common themes across the literature and to apply these themes, and an existing model of compassion fatigue, to informal caregivers for family members with dementia. Findings. Caregivers for family members with dementia may be at risk for developing compassion fatigue. The model of compassion fatigue provides an informative framework for understanding compassion fatigue in the informal caregiver population. Limitations of the model when applied to this population were identified as traumatic memories and the emotional relationship between parent and child, suggesting areas for future research. Conclusions. Research is needed to better understand the impact of compassion fatigue on informal caregivers through qualitative interviews, to identify informal caregivers at risk for compassion fatigue, and to provide an empirical basis for developing nursing interventions for caregivers experiencing compassion fatigue. PMID:22229086

Self-Compassion, Emotion Regulation and Stress among Australian Psychologists: Testing an Emotion Regulation Model of Self-Compassion Using Structural Equation Modeling

PubMed Central

Finlay-Jones, Amy L.; Rees, Clare S.; Kane, Robert T.

2015-01-01

Psychologists tend to report high levels of occupational stress, with serious implications for themselves, their clients, and the discipline as a whole. Recent research suggests that self-compassion is a promising construct for psychologists in terms of its ability to promote psychological wellbeing and resilience to stress; however, the potential benefits of self-compassion are yet to be thoroughly explored amongst this occupational group. Additionally, while a growing body of research supports self-compassion as a key predictor of psychopathology, understanding of the processes by which self-compassion exerts effects on mental health outcomes is limited. Structural equation modelling (SEM) was used to test an emotion regulation model of self-compassion and stress among psychologists, including postgraduate trainees undertaking clinical work (n = 198). Self-compassion significantly negatively predicted emotion regulation difficulties and stress symptoms. Support was also found for our preliminary explanatory model of self-compassion, which demonstrates the mediating role of emotion regulation difficulties in the self-compassion-stress relationship. The final self-compassion model accounted for 26.2% of variance in stress symptoms. Implications of the findings and limitations of the study are discussed. PMID:26207900

Affective and physiological responses to the suffering of others: compassion and vagal activity.

PubMed

Stellar, Jennifer E; Cohen, Adam; Oveis, Christopher; Keltner, Dacher

2015-04-01

Compassion is an affective response to another's suffering and a catalyst of prosocial behavior. In the present studies, we explore the peripheral physiological changes associated with the experience of compassion. Guided by long-standing theoretical claims, we propose that compassion is associated with activation in the parasympathetic autonomic nervous system through the vagus nerve. Across 4 studies, participants witnessed others suffer while we recorded physiological measures, including heart rate, respiration, skin conductance, and a measure of vagal activity called respiratory sinus arrhythmia (RSA). Participants exhibited greater RSA during the compassion induction compared with a neutral control (Study 1), another positive emotion (Study 2), and a prosocial emotion lacking appraisals of another person's suffering (Study 3). Greater RSA during the experience of compassion compared with the neutral or control emotion was often accompanied by lower heart rate and respiration but no difference in skin conductance. In Study 4, increases in RSA during compassion positively predicted an established composite of compassion-related words, continuous self-reports of compassion, and nonverbal displays of compassion. Compassion, a core affective component of empathy and prosociality, is associated with heightened parasympathetic activity. (c) 2015 APA, all rights reserved).

The influence of personality traits and socio-demographic characteristics on paediatric nurses' compassion satisfaction and fatigue.

PubMed

Chen, Yi-Pin; Tsai, Jung-Mei; Lu, Ming-Huei; Lin, Li-Man; Lu, Ching-Hui; Wang, Kai-Wei K

2018-05-01

To explore the level of and the association between, compassion satisfaction and fatigue of paediatric nurses; to determine the association between personality traits and compassion satisfaction and fatigue; to identify the determinants of compassion satisfaction and fatigue. Paediatric nurses are prone to experiencing compassion fatigue associated with caring for children with illness and their families, yet its connection with nurses' personality traits remains unknown. A cross-sectional descriptive study design was used. The data collection used three instruments measuring socio-demography, responses to the compassion satisfaction and fatigue test and the revised NEO personality inventory. The study used descriptive, correlation and multiple regression analysis for the data collected between April - July 2014. From 173 female paediatric nurses, two-thirds worked in critical care units and indicated a satisfactory level of compassion satisfaction and a low level of compassion fatigue, despite a lack of association between the two concepts. Four determinants-agreeableness, extraversion, conscientiousness and engaging with outdoor activities-were predictive and explained 43.6% of total variance of compassion satisfaction. Two risk factors of compassion fatigue identified were less emotional stability and singlehood (marital status) and these explained 26.1% of total variance of compassion fatigue. Support for improving agreeableness and emotional stability in paediatric nurses' workplaces including involvement in the outdoor activities and an increase in social connection may enhance compassion satisfaction and prevent exhaustive compassion fatigue. © 2017 John Wiley & Sons Ltd.

Compassion satisfaction and fatigue: A cross-sectional survey of Australian intensive care nurses.

PubMed

Jakimowicz, Samantha; Perry, Lin; Lewis, Joanne

2017-11-16

Compassion satisfaction and compassion fatigue influence nurses' intention to stay or leave nursing. Identification of compassion satisfaction or fatigue in critical care nurses is important in this high turnover workforce. The aim of this study was to examine factors predicting and contributing to compassion satisfaction and compassion fatigue experienced by critical care nurses in Australian intensive care units. A self-reported cross-sectional survey using an established tool collected data from critical care nurses of two adult Australian intensive care units. Overall, these critical care nurses reported what Professional Quality of Life Scale guidelines designated as 'average' levels of compassion satisfaction and burnout, and 'low' levels of Secondary Traumatic Stress (STS). Compared to Site B, nurses at Site A had significantly higher compassion satisfaction (p=0.008) and lower STS scores (p=0.025), with site significantly predictive for compassion satisfaction (p<0.024) and STS (p<0.002). Nurses with postgraduate qualifications had significantly higher compassion satisfaction scores (p=0.027), and compassion satisfaction significantly increased with increasing duration of practice (p=0.042) as a nurse and in their current ICU (p=0.038). Burnout scores significantly reduced with increasing age, years of tenure and practice; burnout was predicted by lower years of tenure (p<0.016). These critical care nurses revealed profiles that, whilst not in crisis, fell short of the ideal high compassion satisfaction and moderate/low fatigue. More recent tenure flags those potentially at higher risk of compassion fatigue, whilst the better scores associated with postgraduate education and from one site need further exploration. Further research should develop understanding and interventions to enhance compassion satisfaction and support retention of this crucial nursing workforce. Copyright © 2017 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

#fitspo or #loveyourself? The impact of fitspiration and self-compassion Instagram images on women's body image, self-compassion, and mood.

PubMed

Slater, Amy; Varsani, Neesha; Diedrichs, Phillippa C

2017-09-01

This study experimentally examined the impact of exposure to fitspiration images and self-compassion quotes on social media on young women's body satisfaction, body appreciation, self-compassion, and negative mood. Female undergraduate students (N=160) were randomly assigned to view either Instagram images of fitspiration, self-compassion quotes, a combination of both, or appearance-neutral images. Results showed no differences between viewing fitspiration images compared to viewing neutral images, except for poorer self-compassion among those who viewed fitspiration images. However, women who viewed self-compassion quotes showed greater body satisfaction, body appreciation, self-compassion, and reduced negative mood compared to women who viewed neutral images. Further, viewing a combination of fitspiration images and self-compassion quotes led to positive outcomes compared to viewing only fitspiration images. Trait levels of thin-ideal internalisation moderated some effects. The findings suggest that self-compassion might offer a novel avenue for attenuating the negative impact of social media on women's body satisfaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Witness to suffering: mindfulness and compassion fatigue among traumatic bereavement volunteers and professionals.

PubMed

Thieleman, Kara; Cacciatore, Joanne

2014-01-01

This study used a survey to investigate the relationship between mindfulness and compassion fatigue and compassion satisfaction among 41 volunteers and professionals at an agency serving the traumatically bereaved. Compassion fatigue comprises two aspects: secondary traumatic stress and burnout. Because prior research suggests that compassion satisfaction may protect against compassion fatigue, the authors hypothesized that (a) mindfulness would be positively correlated with compassion satisfaction, (b) mindfulness would be inversely correlated with compassion fatigue, and (c) there would be differences between respondents with a personal history of traumatic bereavement and those with no such history. Correlation analyses supported the first two hypotheses; an independent means t test did not provide evidence for the latter hypothesis, although the number ofnontraumatically bereaved respondents was small. Overall, this sample showed surprisingly high levels of compassion satisfaction and low levels of compassion fatigue, even among respondents thought to be at higher risk of problems due to personal trauma. Implications of these findings are particularly relevant for social workers and other professionals employed in positions in which they encounter trauma and high emotional stress.

Compassion fatigue in nurses.

PubMed

Yoder, Elizabeth A

2010-11-01

Compassion fatigue, trigger situations, and coping strategies were investigated in hospital and home care nurses. The Professional Quality of Life Scale measured compassion fatigue, compassion satisfaction, and burnout. Narrative questions elicited trigger situations and coping strategies. Compassion fatigue scores were significantly different between nurses who worked 8- or 12-hour shifts. Fifteen percent of the participants had scores indicating risk of the compassion fatigue. There were significant differences in compassion satisfaction, depending on the unit worked and time as a nurse. The most common category of trigger situations was caring for the patient. Work-related and personal coping strategies were identified. Copyright © 2010 Elsevier Inc. All rights reserved.

To the solar foci

NASA Technical Reports Server (NTRS)

Sonnabend, D.

1979-01-01

Earlier authors showed that the sun is likely to act as a lens for gravitational radiation, with focui in the outer solar system. They suggested that missions to these foci have the potential of directly measuring the density structure of the sun. Other applications include gravitational wave astronomy and tests of general relativity. This idea is reexamined, concentrating on the engineering aspects of focal missions; primarily spacecraft design and performance. Other topics studied include solar optics, gravitational wave detectors, navigation, and the design of missions for different purposes. Specifically, it is shown that shuttle launched chemical rockets have a substantial capability for reaching some foci; and that all can be reached with large payloads using nuclear isotope-electric propulsion.

Compassion Fatigue in the Military Caregiver

DTIC Science & Technology

2009-03-01

Compassion Fatigue/ Burnout Syndrome Figley, C (1995; 97)19 Sprang, Clark, and Whitt-Woosley in their article, “Compassion Fatigue, Compassion...alternative or additional programs, process or intervention to address compassion fatigue, burnout , stress disorder or other debilitating post-traumatic...effects. 15. SUBJECT TERMS Caregiver, Care Provider, Secondary Traumatic Stress, Combat Trauma, Shared Trauma, Posttraumatic Stress Disorder, Burnout 16

Self-Compassion Online: A Pilot Study of an Internet-Based Self-Compassion Cultivation Program for Psychology Trainees.

PubMed

Finlay-Jones, Amy; Kane, Robert; Rees, Clare

2017-07-01

The current study sought to conduct a preliminary investigation of the effectiveness and feasibility of a novel, self-guided online self-compassion training for reducing psychological distress and increasing self-compassion and happiness among psychology trainees. A 6-week online self-compassion cultivation program was developed and delivered to Australian psychology trainees (n = 37), and a pre-experimental repeated-measures design was used to collect change data on self-compassion, happiness, perceived stress, emotion regulation difficulties as well as symptoms of depression, anxiety, and stress. Participants reported significant increases in self-compassion and happiness and significant decreases in depression, stress, and emotion regulation difficulties between pretest and posttest, with the majority of changes maintained at 3-month follow up.  This study provides preliminary evidence supporting the effectiveness and acceptability of online self-compassion training as a positive, integrated, and meaningful way of reducing distress and promoting self-compassion and happiness among trainee psychologists. © 2016 Wiley Periodicals, Inc.

Self-Compassion and the Self-Regulation of Exercise: Reactions to Recalled Exercise Setbacks.

PubMed

Semenchuk, Brittany N; Strachan, Shaelyn M; Fortier, Michelle

2018-02-01

Self-compassion facilitates health behavior self-regulation; few studies have examined self-compassion and exercise. This online, cross-sectional study investigated self-compassion's relationship with exercise self-regulation of an exercise setback. Adults (N = 105) who had experienced an exercise setback within the last 6 months completed baseline measures, recalled an exercise setback, and completed questionnaires assessing self-regulation in this context. Self-compassion associated with self-determined motivations and exercise goal reengagement, and negatively related to extrinsic motivations, state rumination, and negative affect. Self-compassion predicted unique variance, beyond self-esteem, in exercise goal reengagement, external regulation, state rumination, and negative affect experienced after an exercise setback. Self-compassion and self-esteem had unique relationships with goal reengagement, state rumination, and situational motivation, while having a complementary relationship with negative affect. This research adds to the few studies that examine the role of self-compassion in exercise self-regulation by examining how self-compassion and self-esteem relate to reactions to a recalled exercise setback.

Modeling Navigation System Performance of a Satellite-Observing Star Tracker Tightly Integrated with an Inertial Measurement Unit

DTIC Science & Technology

2015-03-26

tracker, an Inertial Measurement Unit (IMU), and a barometric altimeter using an Extended Kalman Filter (EKF). Models of each of these components are...Positioning 15 2.5 Detector Device Improvement . . . . . . . . . . . . . . . 15 2.6 Kalman Filter . . . . . . . . . . . . . . . . . . . . . . . . 17 2.6.1...Extended Kalman Filter . . . . . . . . . . . . . 17 2.7 System Properties . . . . . . . . . . . . . . . . . . . . . 21 2.8 Sun Exitance

The influence of self-compassion on emotional well-being among early and older adolescent males and females

PubMed Central

Bluth, Karen; Blanton, Priscilla W.

2014-01-01

Self-compassion has been associated with well-being in adult samples, but has rarely been assessed in adolescents. In this study, 90 students ages 11–18 completed an online survey assessing self-compassion, life satisfaction, perceived stress and positive and negative affect. Findings indicated that older female adolescents had lower self-compassion than either older male adolescents or early adolescents of either gender, and self-compassion was associated significantly with all dimensions of emotional well-being with the exception of positive affect. Additionally, phase of adolescence, but not gender, was found to moderate the relationship between self-compassion and dimensions of well-being; for older adolescents, the inverse relationship between self-compassion and negative affect was stronger. Lastly, the influence of the various components of self-compassion was investigated and discussed. PMID:25750655

Compassion for others, self-compassion, quality of life and mental well-being measures and their association with compassion fatigue and burnout in student midwives: A quantitative survey.

PubMed

Beaumont, Elaine; Durkin, Mark; Hollins Martin, Caroline J; Carson, Jerome

2016-03-01

compassion fatigue and burnout can impact on the performance of midwives, with this quantitative paper exploring the relationship between self-compassion, burnout, compassion fatigue, self-judgement, self-kindness, compassion for others, professional quality of life and well-being of student midwives. a quantitative survey measured relationships using questionnaires: (1) Professional Quality of Life Scale; (2) Self-Compassion Scale; (3) Short Warwick and Edinburgh Mental Well-being Scale; (4) Compassion For Others Scale. a purposive and convenience sample of student midwives (n=103) studying at university participated in the study. just over half of the sample reported above average scores for burnout. The results indicate that student midwives who report higher scores on the self-judgement sub-scale are less compassionate towards both themselves and others, have reduced well-being, and report greater burnout and compassion fatigue. Student midwives who report high on measures of self-compassion and well-being report less compassion fatigue and burnout. student midwives may find benefit from 'being kinder to self' in times of suffering, which could potentially help them to prepare for the emotional demands of practice and study. developing, creating and cultivating environments that foster compassionate care for self and others may play a significant role in helping midwives face the rigours of education and clinical practice during their degree programme. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vision Based Navigation for Autonomous Cooperative Docking of CubeSats

NASA Astrophysics Data System (ADS)

Pirat, Camille; Ankersen, Finn; Walker, Roger; Gass, Volker

2018-05-01

A realistic rendezvous and docking navigation solution applicable to CubeSats is investigated. The scalability analysis of the ESA Autonomous Transfer Vehicle Guidance, Navigation & Control (GNC) performances and the Russian docking system, shows that the docking of two CubeSats would require a lateral control performance of the order of 1 cm. Line of sight constraints and multipath effects affecting Global Navigation Satellite System (GNSS) measurements in close proximity prevent the use of this sensor for the final approach. This consideration and the high control accuracy requirement led to the use of vision sensors for the final 10 m of the rendezvous and docking sequence. A single monocular camera on the chaser satellite and various sets of Light-Emitting Diodes (LEDs) on the target vehicle ensure the observability of the system throughout the approach trajectory. The simple and novel formulation of the measurement equations allows differentiating unambiguously rotations from translations between the target and chaser docking port and allows a navigation performance better than 1 mm at docking. Furthermore, the non-linear measurement equations can be solved in order to provide an analytic navigation solution. This solution can be used to monitor the navigation filter solution and ensure its stability, adding an extra layer of robustness for autonomous rendezvous and docking. The navigation filter initialization is addressed in detail. The proposed method is able to differentiate LEDs signals from Sun reflections as demonstrated by experimental data. The navigation filter uses a comprehensive linearised coupled rotation/translation dynamics, describing the chaser to target docking port motion. The handover, between GNSS and vision sensor measurements, is assessed. The performances of the navigation function along the approach trajectory is discussed.

Self-Compassion among College Counseling Center Clients: An Examination of Clinical Norms and Group Differences

ERIC Educational Resources Information Center

Lockard, Allison J.; Hayes, Jeffrey A.; Neff, Kristin; Locke, Benjamin D.

2014-01-01

There has been growing interest in the mental health benefits of self-compassion. This study was designed to establish norms on the Self-Compassion Scale-Short Form, a popular measure of self-compassion for individuals seeking counseling, and to examine group differences in self-compassion based on gender, race/ethnicity, sexual orientation,…

Yoga and compassion meditation program improve quality of life and self-compassion in family caregivers of Alzheimer's disease patients: A randomized controlled trial.

PubMed

Danucalov, Marcelo Ad; Kozasa, Elisa H; Afonso, Rui F; Galduroz, José Cf; Leite, José R

2017-01-01

To investigate the effects of the practice of yoga in combination with compassion meditation on the quality of life, attention, vitality and self-compassion of family caregivers of patients with Alzheimer's disease. A total of 46 volunteers were randomly allocated to two groups, the yoga and compassion meditation program group (n = 25), and the control group (CG) that received no treatment (n = 21). The program lasted 8 weeks, and comprised three yoga and meditation practices per week, with each session lasting 1 h and 15 min. Quality of life, attention, vitality, and self-compassion scores were measured pre- and postintervention. The yoga and compassion meditation program group showed statistically significant improvements (P < 0.05) on quality of life, attention, vitality and self-compassion scores as compared with the control group, which showed no statistical significant differences at the postintervention time-point. The findings of the present study suggest that an 8-week yoga and compassion meditation program can improve the quality of life, vitality, attention, and self-compassion of family caregivers of Alzheimer's disease patients. Geriatr Gerontol Int 2017; 17: 85-91. © 2015 Japan Geriatrics Society.

Who is at risk for compassion fatigue? An investigation of genetic counselor demographics, anxiety, compassion satisfaction, and burnout.

PubMed

Lee, Whiwon; Veach, Patricia McCarthy; MacFarlane, Ian M; LeRoy, Bonnie S

2015-04-01

Compassion fatigue is a state of detachment and isolation experienced when healthcare providers repeatedly engage with patients in distress. Compassion fatigue can hinder empathy and cause extreme tension. Prior research suggests 73.8 % of genetic counselors are at moderate to high risk for compassion fatigue and approximately 1 in 4 have considered leaving the field as a result Injeyan et al. (Journal of Genetic Counseling, 20, 526-540, 2011). Empirical data to establish a reliable profile of genetic counselors at risk for compassion fatigue are limited. Thus the purpose of this study was to establish a profile by assessing relationships between state and trait anxiety, burnout, compassion satisfaction, selected demographics and compassion fatigue risk in practicing genetic counselors. Practicing genetic counselors (n = 402) completed an anonymous, online survey containing demographic questions, the State-Trait Anxiety Inventory, and the Professional Quality of Life scale. Multiple regression analysis yielded four significant predictors which increase compassion fatigue risk (accounting for 48 % of the variance): higher levels of trait anxiety, burnout, and compassion satisfaction, and ethnicity other than Caucasian. Additional findings, study limitations, practice implications, and research recommendations are provided.

Compassion Fatigue and Compassion Satisfaction in Hospice Social Work.

PubMed

Pelon, Sally B

2017-01-01

As part of the interprofessional team of hospice caregivers, social workers are exposed to multiple stressors, both in their work with dying patients and their families and in functioning as professionals within rapidly changing health care organizations. Ongoing exposure to such stressors prompts concern about the emotional and psychological effect working with people who are dying may have on those who do it. Further, an understanding is needed regarding how hospice social workers interpret the costs and benefits of their work and how they cope with the dying and loss that pervade their everyday work lives. This descriptive, cross-sectional study explored the prevalence of compassion fatigue among hospice social workers and considered compassion satisfaction as a means to mitigate compassion fatigue. Fifty-five hospice social workers from 34 hospice organizations in Michigan completed an online survey. Results suggested that compassion fatigue is indeed a concern among hospice social workers. In addition, compassion fatigue and compassion satisfaction were found to be negatively correlated and suggested that compassion satisfaction may act as a protective mechanism against compassion fatigue. These results may provide insight regarding how best to mitigate this professional hazard in end-of-life social work.

Compassion fatigue among pediatric healthcare providers.

PubMed

Branch, Carole; Klinkenberg, Dean

2015-01-01

Compassion fatigue is a term used to describe the unique stressors affecting people in caregiving professions. For nurses and other direct care providers, the impact of compassion fatigue may result in stress-related symptoms, job dissatisfaction, decreased productivity, decreased patient satisfaction scores, safety issues, and job turnover. Those who care for seriously ill children and their families are at increased risk for compassion fatigue. Constant exposure to children who are suffering, in combination with work place stressors and personal issues, may contribute to the development of compassion fatigue. The Professional Quality of Life Scale Version 5 was used to determine the risk for compassion fatigue among 296 direct care providers at St. Louis Children's Hospital. Compassion satisfaction, burnout, and secondary traumatic stress scores did not differ by age, work category, level of education, or work experience. There were, however, significant differences in scores as a function of nursing unit. Nurses who work in the pediatric intensive care unit reported lower compassion satisfaction scores, and higher burnout and secondary traumatic stress scores. Results demonstrated the risk for compassion fatigue and provided data necessary to support development of a compassion fatigue program for direct care providers.

Energy Transfer in the Earth-Sun System

NASA Astrophysics Data System (ADS)

Lui, A. T. Y.; Kamide, Y.

2007-02-01

Conference on Earth-Sun System Exploration: Energy Transfer; Kailua-Kona, Hawaii, USA, 16-20 January 2006; The goal of this conference, which was supported by several agencies and organizations, was to provide a forum for physicists engaged in the Earth-Sun system as well as in laboratory experiments to discuss and exchange knowledge and ideas on physical processes involving energy transfer. The motivation of the conference stemmed from the following realization: Space assets form an important fabric of our society, performing functions such as television broadcasting, cell- phone communication, navigation, and remote monitoring of tropospheric weather. There is increasing awareness of how much our daily activities can be adversely affected by space disturbances stretching all the way back to the Sun. In some of these energetic phenomena, energy in various forms can propagate long distances from the solar surface to the interplanetary medium and eventually to the Earth's immediate space environment, namely, its magnetosphere, ionosphere, and thermosphere. In addition, transformation of energy can take place in these space disturbances, allowing charged-particle energy to be transformed to electromagnetic energy or vice versa. In- depth understanding of energy transformation and transmission in the Earth-Sun system will foster the identification of physical processes responsible for space disturbances and the prediction of their occurrences and effects. Participants came from 15 countries.

Orbit determination and orbit control for the Earth Observing System (EOS) AM spacecraft

NASA Technical Reports Server (NTRS)

Herberg, Joseph R.; Folta, David C.

1993-01-01

Future NASA Earth Observing System (EOS) Spacecraft will make measurements of the earth's clouds, oceans, atmosphere, land and radiation balance. These EOS Spacecraft will be part of the NASA Mission to Planet Earth. This paper specifically addresses the EOS AM Spacecraft, referred to as 'AM' because it has a sun-synchronous orbit with a 10:30 AM descending node. This paper describes the EOS AM Spacecraft mission orbit requirements, orbit determination, orbit control, and navigation system impact on earth based pointing. The EOS AM Spacecraft will be the first spacecraft to use the TDRSS Onboard Navigation System (TONS) as the primary means of navigation. TONS flight software will process one-way forward Doppler measurements taken during scheduled TDRSS contacts. An extended Kalman filter will estimate spacecraft position, velocity, drag coefficient correction, and ultrastable master oscillator frequency bias and drift. The TONS baseline algorithms, software, and hardware implementation are described in this paper. TONS integration into the EOS AM Spacecraft Guidance, Navigation, and Control (GN&C) System; TONS assisted onboard time maintenance; and the TONS Ground Support System (TGSS) are also addressed.

Correlates of compassion fatigue and burnout in chaplains and other clergy who responded to the September 11th attacks in New York City.

PubMed

Flannelly, Kevin J; Roberts, Stephen B; Weaver, Andrew J

2005-01-01

Participants at a June 2002 conference about the September 11th attacks were tested for compassion fatigue, compassion satisfaction, and burnout. The sample consisted of 343 clergy, including 97 chaplains. A total of 149 (43.4%) of the participants had responded as disaster-relief workers following the September 11th attacks. The number of hours clergy worked with trauma victims each week was directly related to compassion fatigue among responders and non-responders. Compassion fatigue also was positively related to the number of days that responders worked at Ground Zero, while disaster-relief work with the American Red Cross reduced compassion fatigue and burnout. Clinical Pastoral Education tended to decrease compassion fatigue and burnout and increase compassion satisfaction in both responders and non-responders. Burnout was inversely related to age in both groups.

Cloud-based calculators for fast and reliable access to NOAA's geomagnetic field models

NASA Astrophysics Data System (ADS)

Woods, A.; Nair, M. C.; Boneh, N.; Chulliat, A.

2017-12-01

While the Global Positioning System (GPS) provides accurate point locations, it does not provide pointing directions. Therefore, the absolute directional information provided by the Earth's magnetic field is of primary importance for navigation and for the pointing of technical devices such as aircrafts, satellites and lately, mobile phones. The major magnetic sources that affect compass-based navigation are the Earth's core, its magnetized crust and the electric currents in the ionosphere and magnetosphere. NOAA/CIRES Geomagnetism (ngdc.noaa.gov/geomag/) group develops and distributes models that describe all these important sources to aid navigation. Our geomagnetic models are used in variety of platforms including airplanes, ships, submarines and smartphones. While the magnetic field from Earth's core can be described in relatively fewer parameters and is suitable for offline computation, the magnetic sources from Earth's crust, ionosphere and magnetosphere require either significant computational resources or real-time capabilities and are not suitable for offline calculation. This is especially important for small navigational devices or embedded systems, where computational resources are limited. Recognizing the need for a fast and reliable access to our geomagnetic field models, we developed cloud-based application program interfaces (APIs) for NOAA's ionospheric and magnetospheric magnetic field models. In this paper we will describe the need for reliable magnetic calculators, the challenges faced in running geomagnetic field models in the cloud in real-time and the feedback from our user community. We discuss lessons learned harvesting and validating the data which powers our cloud services, as well as our strategies for maintaining near real-time service, including load-balancing, real-time monitoring, and instance cloning. We will also briefly talk about the progress we achieved on NOAA's Big Earth Data Initiative (BEDI) funded project to develop API interface to our Enhanced Magnetic Model (EMM).

Compassion Fatigue, Burnout, and Compassion Satisfaction Among Oncology Nurses in the United States and Canada.

PubMed

Wu, Stacey; Singh-Carlson, Savitri; Odell, Annie; Reynolds, Grace; Su, Yuhua

2016-07-01

To examine the experiences of compassion fatigue, burnout, and compassion satisfaction among oncology nurses in the United States and Canada. 
. Quantitative, descriptive, nonexperimental.
. Online survey with members from the Canadian Association of Nursing Oncology and the Oncology Nursing Society.
. 486 American and 63 Canadian practicing oncology nurses.
. The Professional Quality of Life (ProQOL) scale, version 5, and modified Abendroth Demographic Questionnaire were administered through FluidSurveys™, an online data collection instrument. Chi-square tests of independence were used to investigate associations between demographic characteristics, health, personal stressors, and work-related characteristics to experiences of compassion fatigue, burnout, and compassion satisfaction. Compassion fatigue was measured using the subscales of secondary traumatic stress and burnout. 
. Compassion fatigue, burnout, and compassion satisfaction.
. Demographic characteristics were similar in American and Canadian participants, and both cohorts reported comparable levels of compassion fatigue, burnout, and compassion satisfaction. Perception of team cohesiveness within the workplace environment was found to be significant for both groups, as indicated by significant relationships in all three subscales of secondary traumatic stress, burnout, and compassion satisfaction in the ProQOL.
. Healthy and supportive work environments are imperative to nurses' health, well-being, and satisfaction. Improvements in the workplace can help prevent negative sequelae, as well as improve health outcomes for patients and nurses, decrease nurse turnover, and reduce healthcare expenditures. 
. Findings can be used to implement institutional changes, such as creating policies and guidelines for the development of preventive interventions and psychosocial support for nurses.

Influence of type D personality on job stress and job satisfaction in clinical nurses: the mediating effects of compassion fatigue, burnout, and compassion satisfaction.

PubMed

Kim, Yeon Hee; Kim, Sung Reul; Kim, Yeo Ok; Kim, Ji Young; Kim, Hyun Kyung; Kim, Hye Young

2017-04-01

To test a hypothetical path model evaluating the influence of type D personality on job stress and job satisfaction and to identify the mediating effects of compassion fatigue, burnout, and compassion satisfaction among clinical nurses in South Korea. Personalities susceptible to stress, compassion fatigue, and burnout in clinical nurses have negative effects on the job stress and job satisfaction. A correlational, cross-sectional design was used. A convenience sample of 875 clinical nurses was recruited between December 2014 - February 2015. The structured questionnaires included the Type D personality scale-14, Professional Quality of Life, job stress, job satisfaction, and general characteristics. To test the hypothetical path model, we performed a path analysis by using the AMOS 18·0 program. Based on the path model, type D personality was significantly associated with compassion fatigue, burnout, and compassion satisfaction in our study subjects. Type D personality was significantly associated with job stress and job satisfaction via the effect of burnout, compassion satisfaction, and job stress. Since type D personality is associated with job stress and job satisfaction, identifying personalities vulnerable to stress would help to address job stress and to enhance job satisfaction when nurses have a high level of compassion fatigue and burnout and a low level of compassion satisfaction. The development of interventions that can reduce negative affect and social inhibition of nurses with type D personality and investigation of methods to decrease their compassion fatigue and burnout and to increase compassion satisfaction should be encouraged. © 2016 John Wiley & Sons Ltd.

Application of Geostationary GNSS and SBAS Satellites for Studying Ionospheric TEC Disturbances of Geomagnetic and Meteorological Origin

NASA Astrophysics Data System (ADS)

Padokhin, A. M.; Kurbatov, G. A.; Yasyukevich, Y.; Yasyukevich, A.

2017-12-01

With the development of GNSS and SBAS constellations, the coherent multi-frequency L band transmissions are now available from a number of geostationary satellites. These signals can be used for ionospheric TEC estimations in the same way as widely used GPS/GLONASS signals. In this work, we compare noise patterns in TEC estimations based on different geostationary satellites data: augmentation systems (Indian GAGAN, European EGNOS and American WAAS), and Chinese COMPASS/Beidou navigation system. We show that noise level in geostationary COMPASS/Beidou TEC estimations is times smaller than noise in SBAS TEC estimation and corresponds to those of GPS/GLONASS at the same elevation angles. We discuss the capabilities of geostationary TEC data for studying ionospheric variability driven by space weather and meteorological sources at different time scales. Analyzing data from IGS/MGEX receivers we present geostationary TEC response on X-class Solar flares of current cycle, moderate and strong geomagnetic storms, including G4 St. Patrick's day Storm 2015 and recent G3 storm of the end of May 2017. We also discuss geostationary TEC disturbances in near equatorial ionosphere caused by two SSW events (minor and major final warming of 2015-2016 winter season) as well as geostationary TEC response on typhoons activity near Taiwan in autumn 2016. Our results show large potential of geostationary TEC estimations with GNSS and SBAS signals for continuous ionospheric monitoring.

The inertial attitude augmentation for ambiguity resolution in SF/SE-GNSS attitude determination.

PubMed

Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

2014-06-26

The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation.

The Inertial Attitude Augmentation for Ambiguity Resolution in SF/SE-GNSS Attitude Determination

PubMed Central

Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

2014-01-01

The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation. PMID:24971472

[DGPPN compass of participation for vocational integration of persons with mental illnesses].

PubMed

Stengler, K; Rauschenbach, J; Riedel-Heller, S G; Becker, T; Steinhart, I; Gerlinger, G; Hauth, I

2016-11-01

Working and living for persons with mental illnesses are a major concern of rehabilitative psychiatry. In Germany the definition of rehabilitation for persons with mental illnesses is closely linked to different sectors of social welfare and to the strongly organized supply chain of prevention, acute treatment, rehabilitation and care. In successfully supporting people with mental health problems in terms of vocational integration, professionals face various obstacles. Besides finding the correct content, structural and organizational difficulties can also arise. The welfare system with its specific institutions and settings is complicated which often leads to delays in the onset of rehabilitation. Some essential reasons are insufficient knowledge about established options of rehabilitative treatment and about responsibilities related to participation in specialized training and further education for professional caregivers. Also information and (positive) experiences from pilot projects working in an inclusive, cross-sectional way and across different settings are practically unavailable in Germany. The presented compass of participation from the German Association for Psychiatry, Psychotherapy and Psychosomatics (DGPPN) for vocational integration of persons with mental illnesses starts at this point: it provides guidelines for psychiatric and psychotherapeutic practitioners, general practitioners as well as for physicians working in residential or day care institutions with a psychiatric and psychotherapeutic background. Both the paper and planned online versions should help professionals to help people, particularly those with severe mental illnesses to navigate the system of services for vocational integration in Germany.

To be kind or not to be kind: The moderating role of self-compassion in the relationship between general resourcefulness and academic self-regulation.

PubMed

Martin, Rebecca D; Kennett, Deborah J

2017-11-22

We investigated whether the relationship between students' general resourcefulness and academic self-regulation changes as a function of self-compassion. A predominantly female sample of 196 undergraduates completed inventories assessing these and other measures. The significant moderating effect of self-compassion revealed that the positive relationship between general resourcefulness and academic self-regulation was stronger for participants scoring low in self-compassion than high in self-compassion. For those low in self-compassion, scoring low in general resourcefulness was associated with the lowest academic self-regulation, whereas scoring high in general resourcefulness was associated with the greatest academic self-regulation. The positive relationship between general and academic self-regulation was attenuated for participants high in self-compassion, with predicted scores for academic self-regulation falling in between the two values described for the low self-compassion function. Implications of the findings are discussed, including the potential value of incorporating self-compassion training alongside programs aimed at increasing general resourcefulness and academic self-regulation.

Self-compassion versus global self-esteem: two different ways of relating to oneself.

PubMed

Neff, Kristin D; Vonk, Roos

2009-02-01

This research examined self-compassion and self-esteem as they relate to various aspects of psychological functioning. Self-compassion entails treating oneself with kindness, recognizing one's shared humanity, and being mindful when considering negative aspects of oneself. Study 1 (N=2,187) compared self-compassion and global self-esteem as they relate to ego-focused reactivity. It was found that self-compassion predicted more stable feelings of self-worth than self-esteem and was less contingent on particular outcomes. Self-compassion also had a stronger negative association with social comparison, public self-consciousness, self-rumination, anger, and need for cognitive closure. Self-esteem (but not self-compassion) was positively associated with narcissism. Study 2 (N=165) compared global self-esteem and self-compassion with regard to positive mood states. It was found that the two constructs were statistically equivalent predictors of happiness, optimism, and positive affect. Results from these two studies suggest that self-compassion may be a useful alternative to global self-esteem when considering what constitutes a healthy self-stance.

Ocellar optics in nocturnal and diurnal bees and wasps.

PubMed

Warrant, Eric J; Kelber, Almut; Wallén, Rita; Wcislo, William T

2006-12-01

Nocturnal bees, wasps and ants have considerably larger ocelli than their diurnal relatives, suggesting an active role in vision at night. In a first step to understanding what this role might be, the morphology and physiological optics of ocelli were investigated in three tropical rainforest species - the nocturnal sweat bee Megalopta genalis, the nocturnal paper wasp Apoica pallens and the diurnal paper wasp Polistes occidentalis - using hanging-drop techniques and standard histological methods. Ocellar image quality, in addition to lens focal length and back focal distance, was determined in all three species. During flight, the ocellar receptive fields of both nocturnal species are centred very dorsally, possibly in order to maximise sensitivity to the narrow dorsal field of light that enters through gaps in the rainforest canopy. Since all ocelli investigated had a slightly oval shape, images were found to be astigmatic: images formed by the major axis of the ocellus were located further from the proximal surface of the lens than images formed by the minor axis. Despite being astigmatic, images formed at either focal plane were reasonably sharp in all ocelli investigated. When compared to the position of the retina below the lens, measurements of back focal distance reveal that the ocelli of Megalopta are highly underfocused and unable to resolve spatial detail. This together with their very large and tightly packed rhabdoms suggests a role in making sensitive measurements of ambient light intensity. In contrast, the ocelli of the two wasps form images near the proximal boundary of the retina, suggesting the potential for modest resolving power. In light of these results, possible roles for ocelli in nocturnal bees and wasps are discussed, including the hypothesis that they might be involved in nocturnal homing and navigation, using two main cues: the spatial pattern of bright patches of daylight visible through the rainforest canopy, and compass information obtained from polarised skylight (from the setting sun or the moon) that penetrates these patches.

Compassion fatigue in pediatric palliative care providers.

PubMed

Rourke, Mary T

2007-10-01

The experience of compassion fatigue is an expected and common response to the professional task of routinely caring for children at the end of life. Symptoms of compassion fatigue often mimic trauma reactions. Implementing strategies that span personal, professional, and organizational domains can help protect health care providers from the damaging effects of compassion fatigue. Providing pediatric palliative care within a constructive and supportive team can help caregivers deal with the relational challenges of compassion fatigue. Finally, any consideration of the toll of providing pediatric palliative care must be balanced with a consideration of the parallel experience of compassion satisfaction.

Adaptive emotion regulation mediates the relationship between self-compassion and depression in individuals with unipolar depression.

PubMed

Diedrich, Alice; Burger, Julian; Kirchner, Mareike; Berking, Matthias

2017-09-01

To identify the mechanisms involved in the association between self-compassion and depression, we examined whether adaptive emotion regulation would mediate the relationship between self-compassion and depression in individuals with unipolar depression. Furthermore, we explored which specific emotion regulation skills would be most important in this relationship. Sixty-nine individuals with unipolar depression were assessed with the Self-Compassion Scale and the Emotion Regulation Skills Questionnaire at baseline and with the Beck Depression Inventory-II 1 week later. The results showed that successful application of emotion regulation skills mediates the association between self-compassion and depression. Among eight specific emotion regulation skills, only the ability to tolerate negative emotions was identified as a significant mediator in the self-compassion-depression relationship. These findings provide preliminary evidence that systematically fostering self-compassion might help depressed individuals cope with their symptoms by enhancing their abilities to tolerate undesired emotions. Systematically fostering self-compassion through specific compassion-focused interventions might facilitate a reduction in depressive symptoms by improving the person's emotion regulation abilities, especially by improving his or her ability to tolerate negative emotions. Hence, compassion-focused interventions might be particularly promising in depressed patients with a tendency to avoid negative emotions and deficits in tolerating them. © 2016 The British Psychological Society.

Women's empowerment: Finding strength in self-compassion.

PubMed

Stevenson, Olivia; Allen, Ashley Batts

2017-03-01

Empowerment is often a desired outcome for health programs; however, it is rarely evaluated. One way to increase empowerment may be through self-compassion. The authors of the current study aimed to determine whether self-compassion and empowerment were positively related. Two hundred and five women (ages 18 to 48 years) were recruited from a pool of undergraduate students at a university in the southeastern United States in the summer/fall of 2012. Participants completed the study using Qualtrics, an online survey system. Participants wrote about a fight in a romantic relationship and were randomly assigned to write about the fight either self-compassionately or generally. Empowerment and perceptions of the fight were assessed as dependent measures. Hierarchical regression analyses investigated the relation of self-compassion, manipulated self-compassion, and their interaction with empowerment. A significant positive relationship was found between self-compassion and empowerment. However, manipulated self-compassion was not significantly related to empowerment. These findings suggested that self-compassion and empowerment were strongly related, but using a short-term self-compassion intervention may not be strong enough to influence empowerment. Empowerment-based practitioners may find empowerment increases more easily in women who are self-compassionate. If self-compassion is incorporated into empowerment settings, a long-term intervention may be necessary.

The family caregiver experience - examining the positive and negative aspects of compassion satisfaction and compassion fatigue as caregiving outcomes.

PubMed

Lynch, Susan H; Shuster, Geoff; Lobo, Marie L

2017-08-16

Caregiving results in both positive and negative outcomes for caregivers. The purpose of this study was to examine compassion fatigue and compassion satisfaction in family caregivers. Using a cross sectional descriptive survey design with a convenience sample, 168 family caregivers of individuals with chronic illness completed a web-based survey. Measures included a demographic questionnaire, Caregiver Burden Interview, Brief COPE inventory and Professional Quality of Life (ProQOL). The majority of participants (71%) reported high levels of caregiver burden, moderate to low levels of the compassion fatigue concepts of burnout (59.5%) and secondary traumatic stress (STS) (50%), and moderate levels of compassion satisfaction (82.7%). Regression analyses showed that caregiver burden, time caregiving, coping, social support, and caregiving demands explained a total variance of 57.1%, F(11,119) = 14.398, p < .00 in burnout and a total variance of 56%, F(11, 119) = 13.64, p < .00 in STS. Specifically, behavioral disengagement is a predicator that may indicate early compassion fatigue. Findings suggest that despite high caregiver burden and moderate compassion fatigue, family caregivers are able to provide care and find satisfaction in the role. This study supports the use of compassion fatigue and compassion satisfaction as alternative or additional outcomes to consider in future research.

Junction detection and pathway selection

NASA Astrophysics Data System (ADS)

Peck, Alex N.; Lim, Willie Y.; Breul, Harry T.

1992-02-01

The ability to detect junctions and make choices among the possible pathways is important for autonomous navigation. In our script-based navigation approach where a journey is specified as a script of high-level instructions, actions are frequently referenced to junctions, e.g., `turn left at the intersection.' In order for the robot to carry out these kind of instructions, it must be able (1) to detect an intersection (i.e., an intersection of pathways), (2) know that there are several possible pathways it can take, and (3) pick the pathway consistent with the high level instruction. In this paper we describe our implementation of the ability to detect junctions in an indoor environment, such as corners, T-junctions and intersections, using sonar. Our approach uses a combination of partial scan of the local environment and recognition of sonar signatures of certain features of the junctions. In the case where the environment is known, we use additional sensor information (such as compass bearings) to help recognize the specific junction. In general, once a junction is detected and its type known, the number of possible pathways can be deduced and the correct pathway selected. Then the appropriate behavior for negotiating the junction is activated.

Navigation in wood ants Formica japonica: context dependent use of landmarks.

PubMed

Fukushi, Tsukasa; Wehner, Rüdiger

2004-09-01

Wood ants Formica japonica can steer their outbound (foraging) and inbound (homing) courses without using celestial compass information, by relying exclusively on landmark cues. This is shown by training ants to run back and forth between the nest and an artificial feeder, and later displacing the trained ants either from the nest (when starting their foraging runs: outbound full-vector ants) or from the feeder (when starting their home runs: inbound full-vector ants) to various nearby release sites. In addition, ants that have already completed their foraging and homing runs are displaced after arrival either at the feeder (outbound zero-vector ants) or at the nest (inbound zero-vector ants), respectively, to the very same release sites. Upon release, the full-vector ants steer their straight courses by referring to panoramic landmark cues, while the zero-vector ants presented with the very same visual scenery immediately search for local landmark cues defining their final goal. Hence, it depends on the context, in this case on the state of the forager's round-trip cycle, what visual cues are picked out from a given set of landmarks and used for navigation.

Visual navigation in desert ants Cataglyphis fortis: are snapshots coupled to a celestial system of reference?

PubMed

Akesson, Susanne; Wehner, Rüdiger

2002-07-01

Central-place foraging insects such as desert ants of the genus Cataglyphis use both path integration and landmarks to navigate during foraging excursions. The use of landmark information and a celestial system of reference for nest location was investigated by training desert ants returning from an artificial feeder to find the nest at one of four alternative positions located asymmetrically inside a four-cylinder landmark array. The cylindrical landmarks were all of the same size and arranged in a square, with the nest located in the southeast corner. When released from the compass direction experienced during training (southeast), the ants searched most intensely at the fictive nest position. When instead released from any of the three alternative directions of approach (southwest, northwest or northeast), the same individuals instead searched at two of the four alternative positions by initiating their search at the position closest to the direction of approach when entering the landmark square and then returning to the position at which snapshot, current landmark image and celestial reference information were in register. The results show that, in the ants' visual snapshot memory, a memorized landmark scene can temporarily be decoupled from a memorized celestial system of reference.

Calibration of Magnetometers with GNSS Receivers and Magnetometer-Aided GNSS Ambiguity Fixing

PubMed Central

Henkel, Patrick

2017-01-01

Magnetometers provide compass information, and are widely used for navigation, orientation and alignment of objects. As magnetometers are affected by sensor biases and eventually by systematic distortions of the Earth magnetic field, a calibration is needed. In this paper, a method for calibration of magnetometers with three Global Navigation Satellite System (GNSS) receivers is presented. We perform a least-squares estimation of the magnetic flux and sensor biases using GNSS-based attitude information. The attitude is obtained from the relative positions between the GNSS receivers in the North-East-Down coordinate frame and prior knowledge of these relative positions in the platform’s coordinate frame. The relative positions and integer ambiguities of the periodic carrier phase measurements are determined with an integer least-squares estimation using an integer decorrelation and sequential tree search. Prior knowledge on the relative positions is used to increase the success rate of ambiguity fixing. We have validated the proposed method with low-cost magnetometers and GNSS receivers on a vehicle in a test drive. The calibration enabled a consistent heading determination with an accuracy of five degrees. This precise magnetometer-based attitude information allows an instantaneous GNSS integer ambiguity fixing. PMID:28594369

Ecological validity of virtual environments to assess human navigation ability

PubMed Central

van der Ham, Ineke J. M.; Faber, Annemarie M. E.; Venselaar, Matthijs; van Kreveld, Marc J.; Löffler, Maarten

2015-01-01

Route memory is frequently assessed in virtual environments. These environments can be presented in a fully controlled manner and are easy to use. Yet they lack the physical involvement that participants have when navigating real environments. For some aspects of route memory this may result in reduced performance in virtual environments. We assessed route memory performance in four different environments: real, virtual, virtual with directional information (compass), and hybrid. In the hybrid environment, participants walked the route outside on an open field, while all route information (i.e., path, landmarks) was shown simultaneously on a handheld tablet computer. Results indicate that performance in the real life environment was better than in the virtual conditions for tasks relying on survey knowledge, like pointing to start and end point, and map drawing. Performance in the hybrid condition however, hardly differed from real life performance. Performance in the virtual environment did not benefit from directional information. Given these findings, the hybrid condition may offer the best of both worlds: the performance level is comparable to that of real life for route memory, yet it offers full control of visual input during route learning. PMID:26074831

Calibration of Magnetometers with GNSS Receivers and Magnetometer-Aided GNSS Ambiguity Fixing.

PubMed

Henkel, Patrick

2017-06-08

Magnetometers provide compass information, and are widely used for navigation, orientation and alignment of objects. As magnetometers are affected by sensor biases and eventually by systematic distortions of the Earth magnetic field, a calibration is needed. In this paper, a method for calibration of magnetometers with three Global Navigation Satellite System (GNSS) receivers is presented. We perform a least-squares estimation of the magnetic flux and sensor biases using GNSS-based attitude information. The attitude is obtained from the relative positions between the GNSS receivers in the North-East-Down coordinate frame and prior knowledge of these relative positions in the platform's coordinate frame. The relative positions and integer ambiguities of the periodic carrier phase measurements are determined with an integer least-squares estimation using an integer decorrelation and sequential tree search. Prior knowledge on the relative positions is used to increase the success rate of ambiguity fixing. We have validated the proposed method with low-cost magnetometers and GNSS receivers on a vehicle in a test drive. The calibration enabled a consistent heading determination with an accuracy of five degrees. This precise magnetometer-based attitude information allows an instantaneous GNSS integer ambiguity fixing.

Multi Sensor Fusion Framework for Indoor-Outdoor Localization of Limited Resource Mobile Robots

PubMed Central

Marín, Leonardo; Vallés, Marina; Soriano, Ángel; Valera, Ángel; Albertos, Pedro

2013-01-01

This paper presents a sensor fusion framework that improves the localization of mobile robots with limited computational resources. It employs an event based Kalman Filter to combine the measurements of a global sensor and an inertial measurement unit (IMU) on an event based schedule, using fewer resources (execution time and bandwidth) but with similar performance when compared to the traditional methods. The event is defined to reflect the necessity of the global information, when the estimation error covariance exceeds a predefined limit. The proposed experimental platforms are based on the LEGO Mindstorm NXT, and consist of a differential wheel mobile robot navigating indoors with a zenithal camera as global sensor, and an Ackermann steering mobile robot navigating outdoors with a SBG Systems GPS accessed through an IGEP board that also serves as datalogger. The IMU in both robots is built using the NXT motor encoders along with one gyroscope, one compass and two accelerometers from Hitecnic, placed according to a particle based dynamic model of the robots. The tests performed reflect the correct performance and low execution time of the proposed framework. The robustness and stability is observed during a long walk test in both indoors and outdoors environments. PMID:24152933

Multi sensor fusion framework for indoor-outdoor localization of limited resource mobile robots.

PubMed

Marín, Leonardo; Vallés, Marina; Soriano, Ángel; Valera, Ángel; Albertos, Pedro

2013-10-21

This paper presents a sensor fusion framework that improves the localization of mobile robots with limited computational resources. It employs an event based Kalman Filter to combine the measurements of a global sensor and an inertial measurement unit (IMU) on an event based schedule, using fewer resources (execution time and bandwidth) but with similar performance when compared to the traditional methods. The event is defined to reflect the necessity of the global information, when the estimation error covariance exceeds a predefined limit. The proposed experimental platforms are based on the LEGO Mindstorm NXT, and consist of a differential wheel mobile robot navigating indoors with a zenithal camera as global sensor, and an Ackermann steering mobile robot navigating outdoors with a SBG Systems GPS accessed through an IGEP board that also serves as datalogger. The IMU in both robots is built using the NXT motor encoders along with one gyroscope, one compass and two accelerometers from Hitecnic, placed according to a particle based dynamic model of the robots. The tests performed reflect the correct performance and low execution time of the proposed framework. The robustness and stability is observed during a long walk test in both indoors and outdoors environments.

[Development and Application of an Overcoming Compassion Fatigue Program for Emergency Nurses].

PubMed

Kim, Yeong Ah; Park, Jeong Sook

2016-04-01

This study was conducted to develop a program to help emergency nurses overcome compassion fatigue, and to analyze the effects of the program. A nonequivalent control group pretest-posttest design was used. There were 14 participants in the experimental group and 18 subjects in the control group. The program was comprised of five, weekly 80-minute sessions including understanding and assessment of compassion fatigue, enhancing positive affect, balancing work-life, planning self care, training in relaxation techniques and cognitive restructuring, and getting social support. Research variables were ego-resiliency, compassion satisfaction and compassion fatigue of the ProQOL 5, and salivary cortisol. Data were analyzed using Chi-square test, independent t-test, and paired t-test. The first hypothesis, "There will be a difference in scores for ego resiliency between the experimental group and the control group". was not supported. The second hypothesis, "There will be a difference in scores for compassion satisfaction between the experimental group and the control group" was supported (t=2.15, p=.046). The third hypothesis, "There will be a difference in scores for compassion fatigue between the experimental group and the control group" was not supported. The first program for emergency nurses to overcome compassion fatigue in Korea was effective in increasing emergency nurses' compassion satisfaction and decreasing salivary cortisol level in the experimental group. Therefore, this program for overcoming compassion fatigue is useful to increase emergency nurses' compassion satisfaction. However replication studies of short-term intensive program reflecting emergency nurses' opinion are needed.

Barriers to Medical Compassion as a Function of Experience and Specialization: Psychiatry, Pediatrics, Internal Medicine, Surgery, and General Practice.

PubMed

Fernando, Antonio T; Consedine, Nathan S

2017-06-01

Compassion is an expectation of patients, regulatory bodies, and physicians themselves. Most research has, however, studied compassion fatigue rather than compassion itself and has concentrated on the role of the physician. The Transactional Model of Physician Compassion suggests that physician, patient, external environment, and clinical factors are all relevant. Because these factors vary both across different specialities and among physicians with differing degrees of experience, barriers to compassion are also likely to vary. We describe barriers to physician compassion as a function of specialization (psychiatry, general practice, surgery, internal medicine, and pediatrics) and physician experience. We used a cross-sectional study using demographic data, specialization, practice parameters, and the Barriers to Physician Compassion Questionnaire. Nonrandom convenience sampling was used to recruit 580 doctors, of whom 444 belonged to the targeted speciality groups. The sample was characterized before conducting a factorial Multivariate Analysis of Covariance and further post hoc analyses. A 5 (speciality grouping) × 2 (more vs. less physician experience) Multivariate Analysis of Covariance showed that the barriers varied as a function of both speciality and experience. In general, psychiatrists reported lower barriers, whereas general practitioners and internal medicine specialists generally reported greater barriers. Barriers were generally greater among less experienced doctors. Documenting and investigating barriers to compassion in different speciality groups have the potential to broaden current foci beyond the physician and inform interventions aimed at enhancing medical compassion. In addition, certain aspects of the training or practice of psychiatry that enhance compassion may mitigate barriers to compassion in other specialities. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Improving the Accuracy of Direct Geo-referencing of Smartphone-Based Mobile Mapping Systems Using Relative Orientation and Scene Geometric Constraints.

PubMed

Alsubaie, Naif M; Youssef, Ahmed A; El-Sheimy, Naser

2017-09-30

This paper introduces a new method which facilitate the use of smartphones as a handheld low-cost mobile mapping system (MMS). Smartphones are becoming more sophisticated and smarter and are quickly closing the gap between computers and portable tablet devices. The current generation of smartphones are equipped with low-cost GPS receivers, high-resolution digital cameras, and micro-electro mechanical systems (MEMS)-based navigation sensors (e.g., accelerometers, gyroscopes, magnetic compasses, and barometers). These sensors are in fact the essential components for a MMS. However, smartphone navigation sensors suffer from the poor accuracy of global navigation satellite System (GNSS), accumulated drift, and high signal noise. These issues affect the accuracy of the initial Exterior Orientation Parameters (EOPs) that are inputted into the bundle adjustment algorithm, which then produces inaccurate 3D mapping solutions. This paper proposes new methodologies for increasing the accuracy of direct geo-referencing of smartphones using relative orientation and smartphone motion sensor measurements as well as integrating geometric scene constraints into free network bundle adjustment. The new methodologies incorporate fusing the relative orientations of the captured images and their corresponding motion sensor measurements to improve the initial EOPs. Then, the geometric features (e.g., horizontal and vertical linear lines) visible in each image are extracted and used as constraints in the bundle adjustment procedure which correct the relative position and orientation of the 3D mapping solution.

Improving the Accuracy of Direct Geo-referencing of Smartphone-Based Mobile Mapping Systems Using Relative Orientation and Scene Geometric Constraints

PubMed Central

Alsubaie, Naif M.; Youssef, Ahmed A.; El-Sheimy, Naser

2017-01-01

This paper introduces a new method which facilitate the use of smartphones as a handheld low-cost mobile mapping system (MMS). Smartphones are becoming more sophisticated and smarter and are quickly closing the gap between computers and portable tablet devices. The current generation of smartphones are equipped with low-cost GPS receivers, high-resolution digital cameras, and micro-electro mechanical systems (MEMS)-based navigation sensors (e.g., accelerometers, gyroscopes, magnetic compasses, and barometers). These sensors are in fact the essential components for a MMS. However, smartphone navigation sensors suffer from the poor accuracy of global navigation satellite System (GNSS), accumulated drift, and high signal noise. These issues affect the accuracy of the initial Exterior Orientation Parameters (EOPs) that are inputted into the bundle adjustment algorithm, which then produces inaccurate 3D mapping solutions. This paper proposes new methodologies for increasing the accuracy of direct geo-referencing of smartphones using relative orientation and smartphone motion sensor measurements as well as integrating geometric scene constraints into free network bundle adjustment. The new methodologies incorporate fusing the relative orientations of the captured images and their corresponding motion sensor measurements to improve the initial EOPs. Then, the geometric features (e.g., horizontal and vertical linear lines) visible in each image are extracted and used as constraints in the bundle adjustment procedure which correct the relative position and orientation of the 3D mapping solution. PMID:28973958

The case for infrasound as the long-range map cue in avian navigation

USGS Publications Warehouse

Hagstrum, J.T.

2007-01-01

Of the various 'map' and 'compass' components of Kramer's avian navigational model, the long-range map component is the least well understood. In this paper atmospheric infrasounds are proposed as the elusive longrange cues constituting the avian navigational map. Although infrasounds were considered a viable candidate for the avian map in the 1970s, and pigeons in the laboratory were found to detect sounds at surprisingly low frequencies (0.05 Hz), other tests appeared to support either of the currently favored olfactory or magnetic maps. Neither of these hypotheses, however, is able to explain the full set of observations, and the field has been at an impasse for several decades. To begin, brief descriptions of infrasonic waves and their passage through the atmosphere are given, followed by accounts of previously unexplained release results. These examples include 'release-site biases' which are deviations of departing pigeons from the homeward bearing, an annual variation in homing performance observed only in Europe, difficulties orienting over lakes and above temperature inversions, and the mysterious disruption of several pigeon races. All of these irregularities can be consistently explained by the deflection or masking of infrasonic cues by atmospheric conditions or by other infrasonic sources (microbaroms, sonic booms), respectively. A source of continuous geographic infrasound generated by atmosphere-coupled microseisms is also proposed. In conclusion, several suggestions are made toward resolving some of the conflicting experimental data with the pigeons' possible use of infrasonic cues.

Kukaniloko: A Living Legend

NASA Astrophysics Data System (ADS)

Barron, Kamira

2011-01-01

This poster investigates a sacred site (heiau) named Kukaniloko on the Hawaiian Island of Oahu. This heiau has been important to the Hawaiians for a number of reasons; it was an ancient astronomical observatory, a navigation school and was the birthplace of a number of prominent kings. Kukaniloko is often mentioned in Hawaiian mythology and ethnohistorical records. Traditionally, it is a place of astronomical, navigational, political, social, educational and ritual importance. Constructed in the 11th century A.D., it has birthing stones, springs, astronomical orientations, and a stone (pohaku) canoe, which is a navigational compass stone. There are contemporary Hawaiians who continue to use this site, and solstices and equinoxes are observed to this day. The guardian/caretaker (kahu) of the site encourages the native community to spend time at Kukaniloko, and those with expertise to help revive the ancient knowledge. Two years ago, he conducted a ceremony of initiation for a new priest (kahuna) during the Autumnal equinox at this heiau. In 1797, King Kamehameha I attempted to have his son born at the site, but his wife's illness prevented her from getting there. Hawaiians interpreted this as the gods’ disapproval of his having committed human sacrifices. The name Kukaniloko can be revealing. The word ku means to stand fast, stop, anchor, also to appear, show, beginning. Kani means sound or noise of any kind, and to strike. Loko means inside, within, disposition, heart, and feelings. The name indicates that this was and still is a place of great importance in Hawaiian culture.

AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL.

PubMed

Zhang, Tao; Chen, Liping; Li, Yao

2015-12-30

This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV.

Flight test of ARINC 741 configuration low gain SATCOM system on Boeing 747-400 aircraft

NASA Technical Reports Server (NTRS)

Murphy, Timothy A.; Stapleton, Brian P.

1990-01-01

The Boeing company conducted a flight test of a SATCOM system similar to the ARINC 741 configuration on a production model 747-400. A flight plan was specifically designed to test the system over a wide variety of satellite elevations and aircraft attitudes as well as over land and sea. Interface bit errors, signal quality and aircraft position and navigational inputs were all recorded as a function of time. Special aircraft maneuvers were performed to demonstrate the potential for shadowing by aircraft structures. Both a compass rose test and the flight test indicated that shadowing from the tail is insignificant for the 747-400. However, satellite elevation angles below the aircraft horizon during banking maneuvers were shown to have a significant deleterious effect on SATCOM communications.

Flight test of ARINC 741 configuration low gain SATCOM system on Boeing 747-400 aircraft

NASA Astrophysics Data System (ADS)

Murphy, Timothy A.; Stapleton, Brian P.

The Boeing company conducted a flight test of a SATCOM system similar to the ARINC 741 configuration on a production model 747-400. A flight plan was specifically designed to test the system over a wide variety of satellite elevations and aircraft attitudes as well as over land and sea. Interface bit errors, signal quality and aircraft position and navigational inputs were all recorded as a function of time. Special aircraft maneuvers were performed to demonstrate the potential for shadowing by aircraft structures. Both a compass rose test and the flight test indicated that shadowing from the tail is insignificant for the 747-400. However, satellite elevation angles below the aircraft horizon during banking maneuvers were shown to have a significant deleterious effect on SATCOM communications.

North Pole, South Pole: the quest to understand the mystery of Earth's magnetism

NASA Astrophysics Data System (ADS)

Turner, G. M.

2010-12-01

The story of the quest to understand Earth’s magnetic field is one of the longest and richest in the history of science. It weaves together Greek philosophy, Chinese mysticism, the development of the compass and navigation, the physics of electromagnetism and the jig-saw like piecing together of the internal structure of the planet beneath our feet. The story begins with Magnes, an old shepherd, trudging up the mountainside after a violent thunder storm, astonished at how the iron studs in his boots stick to the rocks. It was Alexander von Humboldt who, three millennia on, pointed to lightning as the source of such magnetization. The first compass was made 2000 years ago in China - to divine the ways of feng shui - a guide to planting crops, planning streets, orienting buildings and more. It reached Europe as a navigational tool in the 12th century - no-one is quite sure how, but en route it changed from south-pointing to the north-pointing compasses of today. The earliest truly scientific experiments and writings concerned magnets and geomagnetism: Petrus Peregrinus’ Epistola of 1269, and William Gilbert’s De Magnete of1600, in which he declared Magnus magnes globus terrestris ipse est - the Earth itself is a great magnet. By then it was recognized that the compass didn’t point exactly north, and the discrepancy varied from place to place and changed over time - something of a problem for Gilbert’s idea of a geocentric axial dipole. However declination and secular variation were problems well known to Edmund Halley, who, in 1700, charted the angle of declination over the Atlantic Ocean, and in the process introduced the Halleyan line - the contour. Many of the world’s greatest scientists have turned their minds to the problem of magnetism and geomagnetism in particular - Coulomb, Gauss, Faraday, Maxwell - yet in 1905, Einstein described geomagnetism as “one of the great unsolved problems of physics”. In the mid-late nineteenth century new areas of geophysics emerged: geodesy and seismology, and from these came the discoveries of the liquid iron outer core and the inner core. Later, with the recognition and validation of the palaeomagnetic method came the amazing discovery that as well as the gradual secular variation, the polarity of the field has reversed, not once but many times over history. The idea of a simply connected, self-sustaining hydromagnetic dynamo was first proposed by Larmor in 1919, but through most of the 20th century attempts to demonstrate its feasibility were hampered by lack of computational power. When, in the 1990s, supercomputers burst onto the scene it became possible to programme, albeit with some compromises, the many calculations needed to simulate Earth’s core - its motion, electric currents and magnetic fields over a significant part of the life of the Earth. The result was a model that reproduced in character the predominant geocentric axial dipole, the secular variation, and, finally the ability to reverse polarity - the Earth itself is a great hydromagnetic dynamo. The story is told in a new book, published by Awa Press, New Zealand this year, and which is scheduled for publication in the United States early in 2011. Written for a wide audience, it is readily accessible to non-experts and students of any area of earth science.

The cost of callousness: regulating compassion influences the moral self-concept.

PubMed

Cameron, C Daryl; Payne, B Keith

2012-03-01

It has often been argued that compassion is fundamental to morality. Yet people often suppress compassion for self-interested reasons. We provide evidence that suppressing compassion is not cost free, as it creates dissonance between a person's moral identity and his or her moral principles. We instructed separate groups of participants to regulate their compassion, regulate their feelings of distress, or freely experience emotions toward compassion--inducing images. Participants then reported how central morality was to their identities and how much they believed that moral rules should always be followed. Participants who regulated compassion-but not those who regulated distress or experienced emotions--showed a dissonance-based trade-off. If they reported higher levels of moral identity, they had a greater belief that moral rules could be broken. If they maintained their belief that moral rules should always be followed, they sacrificed their moral identity. Regulating compassion thus has a cost of its own: It forces trade-offs within a person's moral self-concept.

Self-compassion moderates body comparison and appearance self-worth's inverse relationships with body appreciation.

PubMed

Homan, Kristin J; Tylka, Tracy L

2015-09-01

Although research on positive body image has increased, little research has explored which variables protect body appreciation during body-related threats. Self-compassion may be one such variable. Individuals high in self-compassion are mindful, kind, and nurturing toward themselves during situations that threaten their adequacy, while recognizing that being imperfect is part of "being human." In this study, we investigated whether two body-related threats (i.e., body comparison and appearance contingent self-worth) were more weakly related to body appreciation when self-compassion was high among an online sample of 263 women (Mage=35.26, SD=12.42). Results indicated that self-compassion moderated the inverse relationships between body related threats and body appreciation. Specifically, when self-compassion was very high, body comparison and appearance contingent self-worth were unrelated to body appreciation. However, when self-compassion was low, these relationships were strong. Self-compassion, then, may help preserve women's body appreciation during body-related threats. Copyright © 2015 Elsevier Ltd. All rights reserved.

Examining the Relationships Among Self-Compassion, Social Anxiety, and Post-Event Processing.

PubMed

Blackie, Rebecca A; Kocovski, Nancy L

2017-01-01

Post-event processing refers to negative and repetitive thinking following anxiety provoking social situations. Those who engage in post-event processing may lack self-compassion in relation to social situations. As such, the primary aim of this research was to evaluate whether those high in self-compassion are less likely to engage in post-event processing and the specific self-compassion domains that may be most protective. In study 1 ( N = 156 undergraduate students) and study 2 ( N = 150 individuals seeking help for social anxiety and shyness), participants completed a battery of questionnaires, recalled a social situation, and then rated state post-event processing. Self-compassion negatively correlated with post-event processing, with some differences depending on situation type. Even after controlling for self-esteem, self-compassion remained significantly correlated with state post-event processing. Given these findings, self-compassion may serve as a buffer against post-event processing. Future studies should experimentally examine whether increasing self-compassion leads to reduced post-event processing.

Definition of compassion-evoking images in a Mexican sample.

PubMed

Mercadillo, Roberto E; Barrios, Fernando A; Díaz, José Luis

2007-10-01

To assemble a calibrated set of compassion-eliciting visual stimuli, 60 clinically healthy Mexican volunteers (36 women, 24 men; M age = 27.5 yr., SD = 2.4) assessed 84 pictures selected from the International Affective Picture System catalogue using the dimensions of Valence, Arousal, and Dominance included in the Self-assessment Manikin scale and an additional dimension of Compassion. Pictures showing suffering in social contexts and expressions of sadness elicited similar responses of compassion. The highest compassion response was reported for pictures showing illness and pain. Men and women differed in the intensity but not the quality of the compassionate responses. Compassion included attributes of negative emotions such as displeasure. The quality of the emotional response was not different from that previously reported for samples in the U.S.A., Spain, and Brazil. A set of 28 pictures was selected as high-compassion-evoking images and 28 as null-compassion controls suitable for studies designed to ascertain the neural substrates of this moral emotion.

Self-Compassion and Responses to Trauma: The Role of Emotion Regulation.

PubMed

Scoglio, Arielle A J; Rudat, Deirdre A; Garvert, Donn; Jarmolowski, Maggie; Jackson, Christie; Herman, Judith L

2018-07-01

Emerging literature suggests that self-compassion may be an important concept for understanding recovery from the impact of trauma and posttraumatic stress disorder (PTSD). The present study explored the interconnection among self-compassion, resilience, emotion dysregulation, and PTSD symptom severity in a sample of treatment-seeking women with PTSD. We predicted that self-compassion would be negatively related to PTSD symptom severity and to emotion dysregulation, and positively related to resilience. The results supported our main hypotheses. In addition, emotion dysregulation mediated the relationship between PTSD symptom severity and self-compassion and affected the relationship between self-compassion and resilience. These findings corroborate previous research that points to the important role of self-compassion in mental health and in the aftermath of stressful life events. The present study expands this research by demonstrating that PTSD symptom severity is negatively related to self-compassion in a clinical population of women with experiences of severe and repeated interpersonal trauma.

Compassion fatigue: A meta-narrative review of the healthcare literature.

PubMed

Sinclair, Shane; Raffin-Bouchal, Shelley; Venturato, Lorraine; Mijovic-Kondejewski, Jane; Smith-MacDonald, Lorraine

2017-04-01

Compassion fatigue describes a work-related stress response in healthcare providers that is considered a 'cost of caring' and a key contributor to the loss of compassion in healthcare. The purpose of this review was to critically examine the construct of compassion fatigue and to determine if it is an accurate descriptor of work-related stress in healthcare providers and a valid target variable for intervention. Meta-narrative review. PubMed, Medline, CINAHL, PsycINFO, and Web of Science databases, Google Scholar, the grey literature, and manual searches of bibliographies. Seminal articles and theoretical and empirical studies on compassion fatigue in the healthcare literature were identified and appraised for their validity and relevance to our review. Sources were mapped according to the following criteria: 1) definitions; 2) conceptual analyses; 3) signs and symptoms; 4) measures; 5) prevalence and associated risk factors; and 6) interventions. A narrative account of included studies that critically examines the concept of compassion fatigue in healthcare was employed, and recommendations for practice, policy and further research were made. 90 studies from the nursing literature and healthcare in general were included in the review. Findings emphasized that the physical, emotional, social and spiritual health of healthcare providers is impaired by cumulative stress related to their work, which can impact the delivery of healthcare services; however, the precise nature of compassion fatigue and that it is predicated on the provision of compassionate care is associated with significant limitations. The conceptualization of compassion fatigue was expropriated from crisis counseling and psychotherapy and focuses on limited facets of compassion. Empirical studies primarily measure compassion fatigue using the Professional Quality of Life Scale, which does not assess any of the elements of compassion. Reported risk factors for compassion fatigue include job-related factors, fewer healthcare qualifications and less years experience; however, there is no research demonstrating that exemplary compassionate carers are more susceptible to 'compassion fatigue'. In the last two decades, compassion fatigue has become a contemporary and iconic euphemism that should be critically reexamined in favour of a new discourse on healthcare provider work-related stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Compassion satisfaction, burnout, and compassion fatigue among emergency nurses compared with nurses in other selected inpatient specialties.

PubMed

Hooper, Crystal; Craig, Janet; Janvrin, David R; Wetsel, Margaret A; Reimels, Elaine

2010-09-01

Today the proportion of acute patients entering the health care system through emergency departments continues to grow, the number of uninsured patients relying primarily on treatment in the emergency department is increasing, and patients' average acuities are rising. At the same time, support resources are constrained, while reimbursement and reputation depends increasingly on publicly available measures of patient satisfaction. It is important to understand the potential effect of these pressures on direct care staff. This study explores the prevalence of compassion satisfaction, burnout, and compassion fatigue among emergency nurses and nurses in other selected inpatient specialties. Emergency nurses and nurses from 3 other specialty units self-selected participation in a cross-sectional survey. Participants completed a sociodemographic profile and the Professional Quality of Life: Compassion Satisfaction and Fatigue Subscales, R-IV. Scale scores were summed for compassion satisfaction, burnout, and compassion fatigue for emergency nurses and compared with those of nurses in other specialties. Approximately 82% of emergency nurses had moderate to high levels of burnout, and nearly 86% had moderate to high levels of compassion fatigue. Differences between emergency nurses and those working in 3 other specialty areas, that is, oncology, nephrology, and intensive care, on the subscales for compassion satisfaction, burnout, or compassion fatigue did not reach the level of statistical significance. However, the scores of emergency nurses evidenced a risk for less compassion satisfaction, while intensive care nurses demonstrated a higher risk for burnout and oncology nurses reflected a risk for higher compassion fatigue. ED nurse managers, along with other nurse leaders, are faced with the competing demands of managing the satisfaction of patients, recruitment and retention of experienced nurses, and provision of quality and safe care customized to patients' needs and preferences. Understanding the concepts of compassion satisfaction, burnout, and compassion fatigue, recognizing the signs and symptoms, and identifying best practice interventions, will help nurses maintain caring attitudes with patients and contribute to patient satisfaction. Copyright © 2010 Emergency Nurses Association. Published by Mosby, Inc. All rights reserved.

Age and Gender Differences in the Associations of Self-Compassion and Emotional Well-being in A Large Adolescent Sample.

PubMed

Bluth, Karen; Campo, Rebecca A; Futch, William S; Gaylord, Susan A

2017-04-01

Adolescence is a challenging developmental period marked with declines in emotional well-being; however, self-compassion has been suggested as a protective factor. This cross-sectional survey study (N = 765, grades 7th to 12th; 53 % female; 4 % Hispanic ethnicity; 64 % White and 21 % Black) examined whether adolescents' self-compassion differed by age and gender, and secondly, whether its associations with emotional well-being (perceived stress, life satisfaction, distress intolerance, depressive symptoms, and anxiety) also differed by age and gender. The findings indicated that older females had the lowest self-compassion levels compared to younger females or all-age males. Self-compassion was associated with all emotional well-being measures, and gender and/or age moderated the associations with anxiety and depressive symptoms. Among older adolescents, self-compassion had a greater protective effect on anxiety for boys than for girls. Additionally, older adolescents with low and average self-compassion had greater levels of depressive symptoms than those with high self-compassion. These results may inform for whom and at what age self-compassion interventions may be implemented to protect adolescents from further declines in emotional well-being.

Compassion satisfaction, compassion fatigue, and burnout in a national sample of trauma treatment therapists.

PubMed

Craig, C D; Sprang, G

2010-05-01

For behavioral health professionals working with traumatized clients, continuous and prolonged exposure to the stress of working with the myriad of trauma-related stressors experienced by their clients can lead to various responses including burnout, compassion fatigue, and compassion satisfaction. The present study investigates the impact of using evidence-based practices on compassion fatigue, burnout, and compassion satisfaction in a random, national sample of self-identified trauma specialists (N=532). The 30-item Professional Quality of Life Scale (Stamm, 2005) and the 19-item Trauma Practices Questionnaire (Craig & Sprang, 2009) were included in a survey to licensed social workers and psychologists from professional membership rosters. Age and years of experience proved to be powerful predictors of only two of the three criterion variables, with younger professionals reporting higher levels of burnout and more experienced providers endorsing higher levels of compassion satisfaction. The utilization of evidence-based practices predicted statistically significant decreases in compassion fatigue and burnout, and increases in compassion satisfaction. The utility of these findings in understanding the process of trauma transmission between therapist and client as well as directions for future research are discussed.

Compassion satisfaction: A concept analysis in nursing.

PubMed

Sacco, Tara L; Copel, Linda Carman

2018-01-01

Nurses experience an intrinsic sense of fulfillment derived from their work in caring for other people. There is a need to further investigate the concept of compassion satisfaction as it is experienced in the profession of nursing. The aim of this analysis is to provide clarity to the concept of compassion satisfaction in nursing. A search of social work and nursing literature was completed. The search terms "compassion satisfaction," "nursing," "social workers," "teachers," and "educators" were entered in various combinations to the CINAHL, Journals@Ovid, ProQuest Nursing & Allied Health Source, ProQuest Psychology Journals, PsychINFO, ERIC, and Education Full Text databases. A comprehensive review of the literature was completed to identify features of compassion satisfaction. Utilizing the Walker and Avant method, assumptions, antecedents, characteristics, and consequences of compassion satisfaction were identified. A conceptual model of compassion satisfaction was developed encompassing 7 antecedents, 11 characteristics, and 8 consequences. Further, a theoretical definition of compassion satisfaction in nursing was derived. There is a need to focus on the positive effects of caring. This concept analysis provides the initial step to strengthening the science related to compassion satisfaction in nursing and other helping professions. © 2017 Wiley Periodicals, Inc.

Age and Gender Differences in the Associations of Self-Compassion and Emotional Well-being in A Large Adolescent Sample

PubMed Central

Bluth, Karen; Campo, Rebecca A.; Futch, William S.; Gaylord, Susan A.

2016-01-01

Adolescence is a challenging developmental period marked with declines in emotional well-being; however, self-compassion has been suggested as a protective factor. This cross-sectional survey study (N=765, grades 7th to 12th; 53% female; 4% Hispanic ethnicity; 64% White and 21% Black) examined whether adolescents’ self-compassion differed by age and gender, and secondly, whether its associations with emotional well-being (perceived stress, life satisfaction, distress intolerance, depressive symptoms, and anxiety) also differed by age and gender. The findings indicated that older females had the lowest self-compassion levels compared to younger females or all-age males. Self-compassion was associated with all emotional well-being measures, and gender and/or age moderated the associations with anxiety and depressive symptoms. Among older adolescents, self-compassion had a greater protective effect on anxiety for boys than for girls. Additionally, older adolescents with low and average self-compassion had greater levels of depressive symptoms than those with high self-compassion. These results may inform for whom and at what age self-compassion interventions may be implemented to protect adolescents from further declines in emotional well-being. PMID:27632177

Compassion satisfaction, compassion fatigue, and critical incident stress management.

PubMed

Wee, David; Myers, Diane

2003-01-01

This study examines the potential for compassion satisfaction, compassion fatigue, and burnout in a sample of persons attending a workshop on Prevention of Compassion Fatigue at an international conference of providers of Critical Incident Stress Management (CISM) services. In the study, more than half (58%) of the respondents reported experiencing psychological reactions after providing CISM services, including an array of behavioral, emotional, cognitive, and physical symptoms of psychological stress. Forty percent of respondents were found to have moderate, high, or extremely high risk for compassion fatigue. At the same time, 89% of respondents were found to have a good, high, or extremely high potential for compassion satisfaction, and 87% were found to be at extremely low risk for burnout. The results appear to indicate that, while the CISM practitioners recognize the stress associated with their work (as reflected in the reported symptoms), the work provides significant rewards (as measured by compassion satisfaction) that outweigh the stress and mitigate against burnout. Likewise, while 40% tested positive for compassion fatigue (or secondary traumatic stress) as a result of their empathy with CISM recipients, the rewards of the work again appear to mitigate the negative effects of the work. Implications for future research and practice are presented.

International study on nurses' views and experiences of compassion.

PubMed

Papadopoulos, I; Zorba, A; Koulouglioti, C; Ali, S; Aagard, M; Akman, O; Alpers, L-M; Apostolara, P; Biles, J; Martín-García, Á; González-Gil, T; Kouta, C; Krepinska, R; Kumar, B N; Lesińska-Sawicka, M; Lopez, L; Malliarou, M; Nagórska, M; Nissim, S; Nortvedt, L; Oter-Quintana, C; Ozturk, C; Pangilinan, S B; Papp, K; Eldar Regev, O; Rubiano, F O; Tolentino Diaz, M Y; Tóthová, V; Vasiliou, M

2016-09-01

Compassion is considered the cornerstone of nursing practice. However, the recent failures in delivering high-quality compassionate nursing care in the UK's National Health Service have brought the topic of compassion to the attention of the public, service providers, policy makers and academics. The aim of this study was to explore the nurses' views and experiences of a number of compassion-related issues in nursing and describe similarities and differences at an international level as well as from the different nursing roles of the participating nurses. An exploratory, cross-sectional descriptive study, using the International Online Compassion Questionnaire. A total of 1323 nurses from 15 countries completed the questionnaire. The majority of participants (59.5%) defined compassion as "Deep awareness of the suffering of others and wish to alleviate it" but definitions of compassion varied by country. Of participants, 69.6% thought compassion was very important in nursing and more than half (59.6%) of them argued that compassion could be taught. However, only 26.8% reported that the correct amount and level of teaching is provided. The majority of the participants (82.6%) stated that their patients prefer knowledgeable nurses with good interpersonal skills. Only 4.3% noted that they are receiving compassion from their managers. A significant relationship was found between nurses' experiences of compassion and their views about teaching of compassion. Our study is unique in identifying the views and experiences of nurses from 15 different countries worldwide. The findings reveal that compassion is neither addressed adequately in nursing education nor supported in the practice environment by managers. Self-report bias was inherent to our survey study design. Furthermore, the individual cultural differences and similarities in the findings are difficult to extrapolate owing to the fact that our analysis was at country level, as well as at the level of the participating nurses. Understanding the influence of culture on nurses' views about compassion is critical in the current multicultural healthcare environment and merits further research. This will potentially drive changes in nursing education (ensuring that compassion is taught to nurses) and in the way healthcare leaders and managers foster a compassionate culture within their organizations (e.g. by leading by example and compassionate to their staff). © 2016 International Council of Nurses.

Compassion fatigue and compassion satisfaction among family physicians in the Republic of Srpska, Bosnia and Herzegovina.

PubMed

Račić, Maja; Virijević, Aleksandra; Ivković, Nedeljka; Joksimović, Bojan N; Joksimović, Vedrana R; Mijovic, Biljana

2018-03-19

The aim of this study was to examine self-perceived compassion fatigue and compassion satisfaction among family physicians in Bosnia and Herzegovina and describe potential contributing factors. The cross-sectional study enrolled 120 family physicians. Professional quality of life compassion satisfaction and fatigue version 5 (ProQOL5) was used to assess compassion satisfaction and two components of compassion fatigue, secondary traumatic stress and burnout. The symptoms of chronic fatigue were evaluated using the Chalder fatigue scale. The majority of family physicians had moderate levels of compassion satisfaction (70%), burnout (75%) and secondary traumatic stress (55.8%). Family physicians with higher levels of secondary traumatic stress reported chronic fatigue (p = 0.001), longer length of service (p = 0.024) and residency training (p = 0.041). Chronic fatigue (p = 0.001), living in a rural environment (p = 0.033), larger size of practice (p = 0.006) and high number of patients with chronic disease (p = 0.001) were associated with a higher risk of burnout. Family physicians with large practices, long years of experience, a high number of chronically ill patients and experiencing chronic fatigue are at risk of developing compassion fatigue. A systematic exploration of compassion fatigue in relation to working conditions might provide an appropriate starting point for the development of preventive interventions.

Self-compassion and emotional invalidation mediate the effects of parental indifference on psychopathology.

PubMed

Westphal, Maren; Leahy, Robert L; Pala, Andrea Norcini; Wupperman, Peggilee

2016-08-30

This study investigated whether self-compassion and emotional invalidation (perceiving others as indifferent to one's emotions) may explain the relationship of childhood exposure to adverse parenting and adult psychopathology in psychiatric outpatients (N=326). Path analysis was used to investigate associations between exposure to adverse parenting (abuse and indifference), self-compassion, emotional invalidation, and mental health when controlling for gender and age. Self-compassion was strongly inversely associated with emotional invalidation, suggesting that a schema that others will be unsympathetic or indifferent toward one's emotions may affect self-compassion and vice versa. Both self-compassion and emotional invalidation mediated the relationship between parental indifference and mental health outcomes. These preliminary findings suggest the potential utility of self-compassion and emotional schemas as transdiagnostic treatment targets. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Role of self-compassion in psychological well-being among perinatal women.

PubMed

Felder, Jennifer N; Lemon, Elizabeth; Shea, Kerry; Kripke, Kate; Dimidjian, Sona

2016-08-01

Self-compassion is associated with depression and anxiety in general samples. Although recent research indicates that dysfunctional maternal attitudes predict the development of perinatal depression and anxiety symptoms, no research to date has examined the construct of self-compassion and its relationship with psychological well-being in perinatal women. Pregnant and postpartum women (N = 189) completed self-report measures of depression and anxiety history, current depression and anxiety symptom severity, and self-compassion. Women with higher depression and anxiety symptom severity had significantly lower self-compassion. Additionally, women with self-reported prior history of depression or anxiety had significantly lower self-compassion even while controlling for current depression or anxiety symptom severity, respectively. Our results suggest that self-compassion warrants further attention in the study of the development, maintenance, and treatment of perinatal mood and anxiety disorders.

Exploring self-compassion and eudaimonic well-being in young women athletes.

PubMed

Ferguson, Leah J; Kowalski, Kent C; Mack, Diane E; Sabiston, Catherine M

2014-04-01

Using a mixed methods research design, we explored self-compassion and eudaimonic well-being in young women athletes. In a quantitative study (n = 83), we found that self-compassion and eudaimonic well-being were positively related (r = .76, p < .01). A model of multiple mediation was proposed, with self-compassion, passivity, responsibility, initiative, and self-determination accounting for 83% of the variance in eudaimonic well-being. In a qualitative study (n = 11), we explored when and how self-compassion might be useful in striving to reach one's potential in sport. Self-compassion was described as advantageous in difficult sport-specific situations by increasing positivity, perseverance, and responsibility, as well as decreasing rumination. Apprehensions about fully embracing a self-compassionate mindset in sport warrant additional research to explore the seemingly paradoxical role of self-compassion in eudaimonic well-being.

Compassion: An Evolutionary Analysis and Empirical Review

PubMed Central

Goetz, Jennifer L.; Keltner, Dacher; Simon-Thomas, Emiliana

2010-01-01

What is compassion? And how did it evolve? In this review, we integrate three evolutionary arguments that converge on the hypothesis that compassion evolved as a distinct affective experience whose primary function is to facilitate cooperation and protection of the weak and those who suffer. Our empirical review reveals compassion to have distinct appraisal processes attuned to undeserved suffering, distinct signaling behavior related to caregiving patterns of touch, posture, and vocalization, and a phenomenological experience and physiological response that orients the individual to social approach. This response profile of compassion differs from those of distress, sadness, and love, suggesting that compassion is indeed a distinct emotion. We conclude by considering how compassion shapes moral judgment and action, how it varies across different cultures, and how it may engage specific patterns of neural activation, as well as emerging directions of research. PMID:20438142

What are healthcare providers’ understandings and experiences of compassion? The healthcare compassion model: a grounded theory study of healthcare providers in Canada

PubMed Central

Sinclair, Shane; Hack, Thomas F; Raffin-Bouchal, Shelley; McClement, Susan; Stajduhar, Kelli; Singh, Pavneet; Sinnarajah, Aynharan; Chochinov, Harvey Max

2018-01-01

Background Healthcare providers are considered the primary conduit of compassion in healthcare. Although most healthcare providers desire to provide compassion, and patients and families expect to receive it, an evidence-based understanding of the construct and its associated dimensions from the perspective of healthcare providers is needed. Objectives The aim of this study was to investigate healthcare providers’ perspectives and experiences of compassion in order to generate an empirically derived, clinically informed model. Design Data were collected via focus groups with frontline healthcare providers and interviews with peer-nominated exemplary compassionate healthcare providers. Data were independently and collectively analysed by the research team in accordance with Straussian grounded theory. Setting and participants 57 healthcare providers were recruited from urban and rural palliative care services spanning hospice, home care, hospital-based consult teams, and a dedicated inpatient unit within Alberta, Canada. Results Five categories and 13 associated themes were identified, illustrated in the Healthcare Provider Compassion Model depicting the dimensions of compassion and their relationship to one another. Compassion was conceptualised as—a virtuous and intentional response to know a person, to discern their needs and ameliorate their suffering through relational understanding and action. Conclusions An empirical foundation of healthcare providers’ perspectives on providing compassionate care was generated. While the dimensions of the Healthcare Provider Compassion Model were congruent with the previously developed Patient Model, further insight into compassion is now evident. The Healthcare Provider Compassion Model provides a model to guide clinical practice and research focused on developing interventions, measures and resources to improve it. PMID:29540416

Compassion Fatigue among Social Work Students in Field Placements

ERIC Educational Resources Information Center

Harr, Cynthia; Moore, Brenda

2011-01-01

This pilot study, conducted with BSW and MSW field students at a public university in Southwestern United States, explored the psychological effect of compassion fatigue and compassion satisfaction on social work students in field placements. Results from the Professional Quality of Life Scale's compassion satisfaction and fatigue subscales…

Nurturing Compassion Development among College Students: A Longitudinal Study

ERIC Educational Resources Information Center

Plante, Thomas; Halman, Katherine

2016-01-01

Little research exists on the development of compassion among college undergraduates. This study tracks changes in compassion and identifies factors associated with these changes over the course of undergraduate students' college careers, from the time of admittance to the time of graduation. Compassion levels assessed at the point of college…

Interacting Compasses

ERIC Educational Resources Information Center

Riveros, Hector G.; Betancourt, Julian

2009-01-01

The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting interactions that occur…

COMPASS: A general purpose computer aided scheduling tool

NASA Technical Reports Server (NTRS)

Mcmahon, Mary Beth; Fox, Barry; Culbert, Chris

1991-01-01

COMPASS is a generic scheduling system developed by McDonnell Douglas under the direction of the Software Technology Branch at JSC. COMPASS is intended to illustrate the latest advances in scheduling technology and provide a basis from which custom scheduling systems can be built. COMPASS was written in Ada to promote readability and to conform to potential NASA Space Station Freedom standards. COMPASS has some unique characteristics that distinguishes it from commercial products. These characteristics are discussed and used to illustrate some differences between scheduling tools.

COMPASS: An Ada based scheduler

NASA Technical Reports Server (NTRS)

Mcmahon, Mary Beth; Culbert, Chris

1992-01-01

COMPASS is a generic scheduling system developed by McDonnell Douglas and funded by the Software Technology Branch of NASA Johnson Space Center. The motivation behind COMPASS is to illustrate scheduling technology and provide a basis from which custom scheduling systems can be built. COMPASS was written in Ada to promote readability and to conform to DOD standards. COMPASS has some unique characteristics that distinguishes it from commercial products. This paper discusses these characteristics and uses them to illustrate some differences between scheduling tools.

Using Acceptance and Commitment Therapy to Increase Self-Compassion: A Randomized Controlled Trial

PubMed Central

Yadavaia, James E.; Hayes, Steven C.; Vilardaga, Roger

2014-01-01

Self-compassion has been shown to be related to several types of psychopathology, including traumatic stress, and has been shown to improve in response to various kinds of interventions. Current conceptualizations of self-compassion fit well with the psychological flexibility model, which underlies acceptance and commitment therapy (ACT). However, there has been no research on ACT interventions specifically aimed at self-compassion. This randomized trial therefore compared a 6-hour ACT-based workshop targeting self-compassion to a wait-list control. From pretreatment to 2-month follow-up, ACT was significantly superior to the control condition in self-compassion, general psychological distress, and anxiety. Process analyses revealed psychological flexibility to be a significant mediator of changes in self-compassion, general psychological distress, depression, anxiety, and stress. Exploratory moderation analyses revealed the intervention to be of more benefit in terms of depression, anxiety, and stress to those with greater trauma history. PMID:25506545

Self-compassion training modulates alpha-amylase, heart rate variability, and subjective responses to social evaluative threat in women

PubMed Central

Arch, Joanna J.; Brown, Kirk Warren; Dean, Derek J.; Landy, Lauren N.; Brown, Kimberley; Laudenslager, Mark L.

2014-01-01

A growing body of research has revealed that social evaluative stressors trigger biological and psychological responses that in chronic forms have been linked to aging and disease. Recent research suggests that self-compassion may protect the self from typical defensive responses to evaluation. We investigated whether brief training in self-compassion moderated biopsychological responses to the Trier Social Stress Test (TSST) in women. Compared to attention (placebo) and no-training control conditions, brief self-compassion training diminished sympathetic (salivary alpha-amylase), cardiac parasympathetic, and subjective anxiety responses, though not HPA-axis (salivary cortisol) responses to the TSST. Self-compassion training also led to greater self-compassion under threat relative to the control groups. In that social stress pervades modern life, self-compassion represents a promising approach to diminishing its potentially negative psychological and biological effects. PMID:24636501

Compassion: an evolutionary analysis and empirical review.

PubMed

Goetz, Jennifer L; Keltner, Dacher; Simon-Thomas, Emiliana

2010-05-01

What is compassion? And how did it evolve? In this review, we integrate 3 evolutionary arguments that converge on the hypothesis that compassion evolved as a distinct affective experience whose primary function is to facilitate cooperation and protection of the weak and those who suffer. Our empirical review reveals compassion to have distinct appraisal processes attuned to undeserved suffering; distinct signaling behavior related to caregiving patterns of touch, posture, and vocalization; and a phenomenological experience and physiological response that orients the individual to social approach. This response profile of compassion differs from those of distress, sadness, and love, suggesting that compassion is indeed a distinct emotion. We conclude by considering how compassion shapes moral judgment and action, how it varies across different cultures, and how it may engage specific patterns of neural activation, as well as emerging directions of research. (c) 2010 APA, all rights reserved.

Is compassion essential to nursing practice?

PubMed

Hem, Marit Helene; Heggen, Kristin

2004-01-01

The Norwegian Nurses' Association recently (2001) approved a new code of ethics that included compassion as one of the basic values in nursing care. This paper examines the idea of compassion in the context of the Bible story of the Good Samaritan using an analysis of qualitative data from nurses' clinical work with psychiatric patients. The aim is to show how the idea of compassion challenges nursing practice. Thereafter, the paper discusses the benefits of and premises for compassion in care work. The results show that nurses tend not to be guided by compassion in their work with patients. The organisation of the day-to-day work in the hospital ward, the division of labour between nurses and doctors, and the nurses' approach to nursing were identified as influencing this tendency. The study shows that compassion is a radical concept with a potential to promote greater respect for patients' dignity.

Using Acceptance and Commitment Therapy to Increase Self-Compassion: A Randomized Controlled Trial.

PubMed

Yadavaia, James E; Hayes, Steven C; Vilardaga, Roger

2014-10-01

Self-compassion has been shown to be related to several types of psychopathology, including traumatic stress, and has been shown to improve in response to various kinds of interventions. Current conceptualizations of self-compassion fit well with the psychological flexibility model, which underlies acceptance and commitment therapy (ACT). However, there has been no research on ACT interventions specifically aimed at self-compassion. This randomized trial therefore compared a 6-hour ACT-based workshop targeting self-compassion to a wait-list control. From pretreatment to 2-month follow-up, ACT was significantly superior to the control condition in self-compassion, general psychological distress, and anxiety. Process analyses revealed psychological flexibility to be a significant mediator of changes in self-compassion, general psychological distress, depression, anxiety, and stress. Exploratory moderation analyses revealed the intervention to be of more benefit in terms of depression, anxiety, and stress to those with greater trauma history.

Compassion Fatigue in Adult Daughter Caregivers of a Parent with Dementia

PubMed Central

Day, Jennifer R.; Anderson, Ruth A.; Davis, Linda L.

2015-01-01

Adult daughters face distinct challenges caring for parents with dementia and may experience compassion fatigue: the combination of helplessness, hopelessness, an inability to be empathic, and a sense of isolation resulting from prolonged exposure to perceived suffering. Prior research on compassion fatigue has focused on professional healthcare providers and has overlooked filial caregivers. This study attempts to identify and explore risk factors for compassion fatigue in adult daughter caregivers and to substantiate further study of compassion fatigue in family caregivers. We used content analysis of baseline interviews with 12 adult daughter caregivers of a parent with dementia who participated in a randomized trial of homecare training. Four themes were identified in adult daughter caregiver interviews: (a) uncertainty; (b) doubt; (c) attachment; and (d) strain. Findings indicated adult daughter caregivers are at risk for compassion fatigue, supporting the need for a larger study exploring compassion fatigue in this population. PMID:25259643

Compassion fatigue and burnout: what managers should know.

PubMed

Slatten, Lise Anne; David Carson, Kerry; Carson, Paula Phillips

2011-01-01

Most health care employees experience and are bolstered by compassion satisfaction as they deal with patients in need. However, the more empathetic a health care provider is, the more likely he or she will experience compassion fatigue. Compassion fatigue is a negative syndrome that occurs when dealing with the traumatic experiences of patients, and examples of symptoms include intrusive thoughts, sleeping problems, and depression. Compassion fatigue is different from burnout. Compassion fatigue is a rapidly occurring disorder for primary health care workers who work with suffering patients, whereas burnout, a larger construct, is a slowly progressing disorder for employees who typically are working in burdensome organizational environments. Managers can mitigate problems associated with compassion fatigue with a number of interventions including patient reassignments, formal mentoring programs, employee training, and a compassionate organizational culture. With burnout, health care managers will want to focus primarily on chronic organizational problems.

Compassion, pride, and social intuitions of self-other similarity.

PubMed

Oveis, Christopher; Horberg, E J; Keltner, Dacher

2010-04-01

Compassion and pride serve contrasting social functions: Compassion motivates care-taking behavior, whereas pride enables the signaling and negotiation of rank within social hierarchies. Across 3 studies, compassion was associated with increased perceived self-other similarity, particularly to weak or vulnerable others. In contrast, pride was associated with an enhanced sense of similarity to strong others, and a decreased sense of similarity to weak others. These findings were obtained using trait measures (Study 1) and experimental inductions (Studies 2 and 3) of compassion and pride, examining the sense of similarity to strong or weak groups (Studies 1 and 2) and unfamiliar individuals (Study 3). The influences of compassion and pride on perceived self-other similarity could not be accounted for by positive mood, nor was this effect constrained by the ingroup status of the target group or individual. Discussion focuses on the contributions these findings make to an understanding of compassion and pride.

A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

PubMed

Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

2007-09-26

The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

Understanding the Transformation of Compassion in Nurses Who Become Patients

ERIC Educational Resources Information Center

Pucino, Carrie L.

2013-01-01

The purpose of this study was to examine how nurses who become patients learn compassion toward patients in their professional practice, and examine the role of empathy in the process of learning compassion. The process of learning compassion represents a significant change in the way nurses perceive this aspect of practice. Therefore,…

Compassion Fatigue and Compassion Satisfaction among Residential Child Care Workers: The Role of Personality Resources

ERIC Educational Resources Information Center

Zerach, Gadi

2013-01-01

This study assessed compassion fatigue (CF) and compassion satisfaction (CS) among Israeli residential child-care workers (RCWs) working in residential treatment facilities for children and youth at risk (N = 147) as compared to educational boarding schools workers (BSWs; N = 74). Furthermore, we assessed the relationship of potential…

Self-Compassion and the Dynamics of Investigating Sexual Harassment

ERIC Educational Resources Information Center

Serri, Conchita Franco

2006-01-01

What role does compassion play in one's work? In the author's organization, the word "compassion" has been mostly linked to their values, mission, and programs. She has generally understood the concept of compassion as a deep feeling of empathy that flows from oneself towards others during certain situations and conditions. In her mind, "having…

Rousseau and the Education of Compassion

ERIC Educational Resources Information Center

White, Richard

2008-01-01

In this paper I examine Rousseau's strategy for teaching compassion in "Book Four of Emile." In particular, I look at the three maxims on compassion that help to organise Rousseau's discussion, and the precise strategy that Emile's tutor uses to instil compassion while avoiding other passions, such as anger, fear and pride. The very idea of an…

Compassion: An Evolutionary Analysis and Empirical Review

ERIC Educational Resources Information Center

Goetz, Jennifer L.; Keltner, Dacher; Simon-Thomas, Emiliana

2010-01-01

What is compassion? And how did it evolve? In this review, we integrate 3 evolutionary arguments that converge on the hypothesis that compassion evolved as a distinct affective experience whose primary function is to facilitate cooperation and protection of the weak and those who suffer. Our empirical review reveals compassion to have distinct…

Compassion Fatigue Risk and Self-Care Practices among Residential Treatment Center Childcare Workers

ERIC Educational Resources Information Center

Eastwood, Callum D.; Ecklund, Kathryn

2008-01-01

Exploration of the presence of risk for compassion fatigue among residential childcare workers (RCW) at residential treatment facilities and the relationship between self-care practices and compassion fatigue were explored. Using the Professional Quality of Life Survey (ProQOL-R III) to assess compassion fatigue, burnout, and compassion…

46 CFR 108.715 - Magnetic compass and gyrocompass.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise service must have a magnetic compass. (b) Each self-propelled unit of 1...

46 CFR 167.40-45 - Magnetic compass and gyrocompass.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

46 CFR 108.715 - Magnetic compass and gyrocompass.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise service must have a magnetic compass. (b) Each self-propelled unit of 1...

46 CFR 167.40-45 - Magnetic compass and gyrocompass.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

A daily diary study of self-compassion, body image, and eating behavior in female college students.

PubMed

Kelly, Allison C; Stephen, Elizabeth

2016-06-01

Although self-compassion is associated with healthier body image and eating behavior, these findings have generally emerged at the between-persons level only. The present study investigated the unique contributions of within-person variability in self-compassion, and between-persons differences in self-compassion, to body image and eating behavior. Over seven days, 92 female college students completed nightly measures of self-compassion, self-esteem, dietary restraint, intuitive eating, body appreciation, body satisfaction, and state body image. Multilevel modeling revealed that within-persons, day-to-day fluctuations in self-compassion contributed to day-to-day fluctuations in body image and eating. Between-persons, participants' average levels of self-compassion across days contributed to their average levels of body image and eating over the week. Results generally held when controlling for within- and between-persons self-esteem. Evidently, the eating and body image benefits of self-compassion may come not only from being a generally self-compassionate person, but also from treating oneself more self-compassionately than usual on a given day. Copyright © 2016 Elsevier Ltd. All rights reserved.

Compassion Satisfaction and Compassion Fatigue Among Critical Care Nurses.

PubMed

Sacco, Tara L; Ciurzynski, Susan M; Harvey, Megan Elizabeth; Ingersoll, Gail L

2015-08-01

Although critical care nurses gain satisfaction from providing compassionate care to patients and patients' families, the nurses are also at risk for fatigue. The balance between satisfaction and fatigue is considered professional quality of life. To establish the prevalence of compassion satisfaction and compassion fatigue in adult, pediatric, and neonatal critical care nurses and to describe potential contributing demographic, unit, and organizational characteristics. In a cross-sectional design, nurses were surveyed by using a demographic questionnaire and the Professional Quality of Life Scale to measure levels of compassion fatigue and compassion satisfaction. Nurses (n = 221) reported significant differences in compassion satisfaction and compassion fatigue on the basis of sex, age, educational level, unit, acuity, change in nursing management, and major systems change. Understanding the elements of professional quality of life can have a positive effect on work environment. The relationship between professional quality of life and the standards for a healthy work environment requires further investigation. Once this relationship is fully understood, interventions to improve this balance can be developed and tested. ©2015 American Association of Critical-Care Nurses.

Use of a brief version of the self-compassion inventory with an international sample of people with HIV/AIDS

PubMed Central

Brion, John M.; Leary, Mark; Wantland, Dean; Sullivan, K.; Nokes, Kathleen; Bain, Catherine A; Chaiphibalsarisdi, Puangtip; Chen, Wei-ti; Holzemer, William L.; Eller, Lucille Sanzero; Iipinge, Scholastika; Johnson, Mallory O.; Portillo, Carmen; Voss, Joachim; Tyer-Viola, Lynda; Corless, Inge B; Nicholas, Patrice K; Rose, Carol Dawson; Phillips, J. Craig; Sefcik, Elizabeth; Mendez, Marta Rivero; Kirksey, Kenn M.

2013-01-01

The objective of this study was to extend the psychometric evaluation of a brief version of the Self Compassion Scale (SCS). A secondary analysis of data from an international sample of 1,967 English-speaking persons living with HIV disease was used to examine the factor structure, and reliability of the 12-item Brief Version Self Compassion Inventory (BVSCI). A Maximum Likelihood factor analysis and Oblimin with Kaiser Normalization confirmed a two-factor solution, accounting for 42.58% of the variance. The BVSCI supported acceptable internal consistencies, with .714 for the total scale and .822 for Factor I and .774 for Factor II. Factor I (lower self compassion) demonstrated strongly positive correlations with measures of anxiety and depression while Factor II (high self compassion) was inversely correlated with the measures. No significant differences were found in the BVSCI scores for gender, age, or having children. Levels of self-compassion were significantly higher in persons with HIV disease and other physical and psychological health conditions. The scale shows promise for the assessment of self-compassion in persons with HIV without taxing participants, and may prove essential in investigating future research aimed at examining correlates of self-compassion, as well as providing data for tailoring self-compassion interventions for persons with HIV. PMID:23527887

The paradox of compassionate work: a mixed-methods study of satisfying and fatiguing experiences of animal health care providers.

PubMed

Polachek, Alicia J; Wallace, Jean E

2018-03-01

Compassionate work appears paradoxical as it may provide great rewards, but may also come at great costs to care providers. This paper explores the paradox of compassionate work by examining what interactions contribute to compassion satisfaction and what interactions contribute to compassion fatigue. This mixed-methods, cross-sectional study uses qualitative interview data from animal health care providers (N = 20) to identify work interactions that they find satisfying or stressful. Quantitative survey data (N = 572) are used to test hypotheses generated from the interviews regarding predictors of compassion satisfaction and compassion fatigue. Interview transcripts were analyzed using a directed content analysis approach. Survey data were analyzed using ordinary least squares regression. The results highlight the complex nature of compassionate work. As hypothesized, making a difference to animals and building relationships with animal patients and human clients relate to greater compassion satisfaction. Human client barriers to animal care and witnessing client grief relate to greater compassion fatigue, as predicted. None of the predictors relate to less compassion fatigue, but forming relationships with animal patients relates to both greater compassion satisfaction and compassion fatigue. This paper enhances our understanding of provider-client-patient interactions and highlights the paradox of compassionate work.

The protective role of compassion satisfaction for therapists who work with sexual violence survivors: an application of the broaden-and-build theory of positive emotions.

PubMed

Samios, Christina; Abel, Lisa M; Rodzik, Amber K

2013-01-01

Therapists who work with trauma survivors, such as survivors of sexual violence, can experience compassion satisfaction while experiencing negative effects of trauma work, such as secondary traumatic stress. We examined whether the negative effects of secondary traumatic stress on therapist adjustment would be buffered by compassion satisfaction and whether the broaden-and-build theory of positive emotions could be applied to examine the factors (positive emotions and positive reframing) that relate to compassion satisfaction. Sixty-one therapists who work with sexual violence survivors completed measures of secondary traumatic stress, compassion satisfaction, adjustment, positive emotions and positive reframing. Hierarchical multiple regression analyses found that compassion satisfaction buffered the negative impact of secondary traumatic stress on therapist adjustment when adjustment was conceptualised as anxiety. Using non-parametric bootstrapping, we found that the relationship between greater positive emotions and greater compassion satisfaction was partially mediated by positive reframing. The findings indicate that compassion satisfaction is likely to be helpful in ameliorating the negative effects of secondary traumatic stress on anxiety in therapists who work with sexual violence survivors and that the broaden-and-build theory of positive emotions may provide a strong theoretical basis for the further examination of compassion satisfaction in trauma therapists.

Compassion, Mindfulness, and the Happiness of Healthcare Workers.

PubMed

Benzo, Roberto P; Kirsch, Janae L; Nelson, Carlie

Decreased well-being of healthcare workers expressed as stress and decreased job satisfaction influences patient safety, patient satisfaction, and cost containment. Self-compassion has garnered recent attention due to its positive association with well-being and happiness. Discovering novel pathways to increase the well-being of healthcare workers is essential. This study sought to explore the influence of self-compassion on employee happiness in healthcare professionals. A total of 400 participants (mean age = 45 ± 14, 65% female) healthcare workers at a large teaching hospital were randomly asked to complete questionnaires assessing their levels of happiness and self-compassion, life conditions, and habits. Participants completed the Happiness Scale and Self-Compassion Scales, the Five Facet Mindfulness Questionnaire as well as variables associated with well-being: relationship status, the number of hours spent exercising a week, attendance at a wellness facility, and engagement in a regular spiritual practice. Self-compassion was significantly and independently associated with perceived happiness explaining 39% of its variance after adjusting for age, marital status, gender, time spent exercising, and attendance to an exercise facility. Two specific subdomains of self-compassion from the instrument used, coping with isolation and mindfulness, accounted for 95% of the self-compassion effect on happiness. Self-compassion is meaningfully and independently associated with happiness and well-being in healthcare professionals. Our results may have practical implications by providing specific self-compassion components to be targeted in future programs aimed at enhancing well-being in healthcare professionals. Copyright © 2017 Elsevier Inc. All rights reserved.

Compassion, Mindfulness and the Happiness of Health Care Workers

PubMed Central

Benzo, Roberto P.; Kirsch, Janae L.; Nelson, Carlie

2017-01-01

Context Decreased well-being of health care workers expressed as stress and decreased job satisfaction influences patient safety and satisfaction and cost containment. Self-compassion has garnered recent attention due to its positive association with wellbeing and happiness. Discovering novel pathways to increase the well-being of health care workers is essential. Objective This study sought to explore the influence of self-compassion on employee happiness in health care professionals. Design, Setting & Participants 400 participants (mean age 45 ± 14, 65% female) health care workers at a large teaching hospital were randomly asked to complete questionnaires assessing their levels of happiness and self-compassion, life conditions and habits. Measures Participants completed the Happiness Scale and Self-Compassion Scales, the Five Facet Mindfulness Questionnaire as well as variables associated with wellbeing: relationship status, the number of hours spent exercising a week, attendance at a wellness facility and engagement in a regular spiritual practice. Results Self-compassion was significantly and independently associated with perceived happiness explaining 39% of its variance after adjusting for age, marital status, gender, time spent exercising and attendance to an exercise facility. Two specific subdomains of self-compassion from the instrument used, coping with isolation and mindfulness, accounted for 95% of the self-compassion effect on happiness. Conclusion Self-compassion is meaningfully and independently associated with happiness and well-being in health care professionals. Our results may have practical implications by providing specific self-compassion components to be targeted in future programs aimed at enhancing wellbeing in health care professionals. PMID:28420563

Influence of fears of compassion on body image shame and disordered eating.

PubMed

Dias, Bernardo Santos; Ferreira, Cláudia; Trindade, Inês A

2018-06-07

The current study tested a path model examining the impact of fears of compassion in the adoption of disordered eating and whether social safeness and body shame would mediate this relationship. Participants were 645 women (aged between 18 and 55) from the general community, who completed an online survey. Results indicated that fears of compassion were negatively associated with one's ability to feel secure and safe within close relationships, and positively linked with higher levels of body shame and disordered eating. The tested model accounted for 62% of the variance of disordered eating. Path analyses results revealed that the three dimensions of fears of compassion impacted on disordered eating. Particularly, fear of expressing compassion for others presented a direct impact on disordered eating. Moreover, fears of self-compassion and fears of receiving compassion from others partially impacted on disordered eating attitudes and behaviours, through the mechanisms of social safeness and body image-focused shame. These findings suggested that women who present higher levels of fear of self-compassion and of receiving signs of affection and compassion from others tend to feel more insecure in their social group, which seem explain body shame and the engagement in disordered eating behaviours. This study highlights the pathogenic impact of fears of compassion on body image and eating attitudes and behaviours. The current data seem to offer relevant insights for research and clinical practice, by supporting the relevance of developing compassionate abilities and attitudes to target body image and eating-related difficulties.

Effect of Meaningful Recognition on Critical Care Nurses' Compassion Fatigue.

PubMed

Kelly, Lesly A; Lefton, Cindy

2017-11-01

As caregivers in high-pressure environments, critical care nurses are at risk for burnout and secondary trauma-components of compassion fatigue. Recent findings have increased understanding of the phenomena, specifically that satisfaction and meaningful recognition may play a role in reducing burnout and raising compassion satisfaction; however, no large multisite studies of compassion fatigue have been conducted. To examine the effect of meaningful recognition and other predictors on compassion fatigue in a multicenter national sample of critical care nurses. A quantitative, descriptive online survey was completed by 726 intensive care unit nurses in 14 hospitals with an established meaningful recognition program and 410 nurses in 10 hospitals without such a program. Site coordinators at each hospital coordinated distribution of the survey to nurses to assess multiple predictors against outcomes, measured by the Professional Quality of Life Scale. Cross-validation and linear regression modeling were conducted to determine significant predictors of burnout, secondary traumatic stress, and compassion satisfaction. Similar levels of burnout, secondary traumatic stress, compassion satisfaction, overall satisfaction, and intent to leave were reported by nurses in hospitals with and without meaningful recognition programs. Meaningful recognition was a significant predictor of decreased burnout and increased compassion satisfaction. Additionally, job satisfaction and job enjoyment were highly predictive of decreased burnout, decreased secondary traumatic stress, and increased compassion satisfaction. In addition to acknowledging and valuing nurses' contributions to care, meaningful recognition could reduce burnout and boost compassion satisfaction. ©2017 American Association of Critical-Care Nurses.

How are compassion fatigue, burnout, and compassion satisfaction affected by quality of working life? Findings from a survey of mental health staff in Italy.

PubMed

Cetrano, Gaia; Tedeschi, Federico; Rabbi, Laura; Gosetti, Giorgio; Lora, Antonio; Lamonaca, Dario; Manthorpe, Jill; Amaddeo, Francesco

2017-11-21

Quality of working life includes elements such as autonomy, trust, ergonomics, participation, job complexity, and work-life balance. The overarching aim of this study was to investigate if and how quality of working life affects Compassion Fatigue, Burnout, and Compassion Satisfaction among mental health practitioners. Staff working in three Italian Mental Health Departments completed the Professional Quality of Life Scale, measuring Compassion Fatigue, Burnout, and Compassion Satisfaction, and the Quality of Working Life Questionnaire. The latter was used to collect socio-demographics, occupational characteristics and 13 indicators of quality of working life. Multiple regressions controlling for other variables were undertaken to predict Compassion Fatigue, Burnout, and Compassion Satisfaction. Four hundred questionnaires were completed. In bivariate analyses, experiencing more ergonomic problems, perceiving risks for the future, a higher impact of work on life, and lower levels of trust and of perceived quality of meetings were associated with poorer outcomes. Multivariate analysis showed that (a) ergonomic problems and impact of work on life predicted higher levels of both Compassion Fatigue and Burnout; (b) impact of life on work was associated with Compassion Fatigue and lower levels of trust and perceiving more risks for the future with Burnout only; (c) perceived quality of meetings, need of training, and perceiving no risks for the future predicted higher levels of Compassion Satisfaction. In order to provide adequate mental health services, service providers need to give their employees adequate ergonomic conditions, giving special attention to time pressures. Building trustful relationships with management and within the teams is also crucial. Training and meetings are other important targets for potential improvement. Additionally, insecurity about the future should be addressed as it can affect both Burnout and Compassion Satisfaction. Finally, strategies to reduce possible work-life conflicts need to be considered.

The emotion of compassion and the likelihood of its expression in nursing practice.

PubMed

Newham, Roger Alan

2017-07-01

Philosophical and empirical work on the nature of the emotions is extensive, and there are many theories of emotions. However, all agree that emotions are not knee jerk reactions to stimuli and are open to rational assessment or warrant. This paper's focus is on the condition or conditions for compassion as an emotion and the likelihood that it or they can be met in nursing practice. Thus, it is attempting to keep, as far as possible, compassion as an emotion separate from both moral norms and professional norms. This is because empirical or causal conditions that can make experiencing and acting out of compassion difficult seem especially relevant in nursing practice. I consider how theories of emotion in general and of compassion in particular are somewhat contested, but all recent accounts agree that emotions are not totally immune to reason. Then, using accounts of constitutive conditions of the emotion of compassion, I will show how they are often likely to be quite fragile or unstable in practice and particularly so within much nursing practice. In addition, some of the conditions for compassion will be shown to be problematic for nursing practice. It is difficult to keep ideas of compassion separate from morality, and this connection is noticeable in the claims made of compassion for nursing and so I will briefly highlight one such connection that of the need for normative theory to give an account of the value that emotions such as compassion presume and that compassionate motivation is separate from moral motivation and may conflict with it. The fragility or instability of the emotion of compassion in practice has implications for both what can be expected and what should be expected of compassion; at least if what is wanted is a realist rather than idealist account of "should." © 2016 John Wiley & Sons Ltd.

Sun-Burned: Space Weather’s Impact On U.S. National Security

DTIC Science & Technology

2013-06-01

for navigation, the wideband global satellite communications system used for secure links in multiple frequencies , the space-based infrared system...used for early warning missile detection, the advanced extremely high frequency used for jam resistant strategic communications , and the defense...NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11 . SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for

Polarimetric Enhancements to Electro-Optical Aided Navigation Techniques

DTIC Science & Technology

2011-03-01

encouraging me in every step of the way. I give a sincere thanks to the folks in AFRL/RYJT that started me working with polaremetry. Especially Bab Mack ...57 3.14 Polarization Products Examples . . . . . . . . . . . . . . . . . 60 ix Figure Page 3.15 Hue, Intensity, Saturation Pseudo- color ...Figure 3.6: Example output image from the DIRSIG software. This image shows the intensity of three glossy black objects being illuminated by the sun

The sunstone and polarised skylight: ancient Viking navigational tools?

NASA Astrophysics Data System (ADS)

Ropars, Guy; Lakshminarayanan, Vasudevan; Le Floch, Albert

2014-10-01

Although the polarisation of the light was discovered at the beginning of the nineteenth century, the Vikings could have used the polarised light around the tenth century in their navigation to America, using a 'sunstone' evoked in the Icelandic Sagas. Indeed, the birefringence of the Iceland spar (calcite), a common crystal in Scandinavia, permits a simple observation of the axis of polarisation of the skylight at the zenith. From this, it is possible to guess the azimuth of a hidden Sun below the horizon, for instance. The high sensitivity of the differential method provided by the ordinary and extraordinary beams of calcite at its so-called isotropy point is about two orders higher than that of the best dichroic polariser and permits to reach an accuracy of ±1° for the Sun azimuth (at sunrise and sunset). Unfortunately, due to the relative fragility of calcite, only the so-called Alderney crystal was discovered on board a 16th ancient ship. Curiously, beyond its use as a sunstone by the Vikings, during these last millennia calcite has led to the discovery of the polarisation of the light itself by Malus and is currently being used to detect the atmospheres of exoplanets. Moreover, the differential method for the light polarisation detection is widely used in the animal world.

Compassion Fatigue, Compassion Satisfaction, and Burnout: Factors Impacting a Professional's Quality of Life

ERIC Educational Resources Information Center

Sprang, Ginny; Whitt-Woosley, Adrienne; Clark, James J.

2007-01-01

This study examined the relationship between three variables, compassion fatigue (CF), compassion satisfaction (CS), and burnout, and provider and setting characteristics in a sample of 1,121 mental health providers in a rural southern state. Respondents completed the Professional Quality of Life Scale as part of a larger survey of provider…

Self-Compassion as a Predictor of Psychological Entitlement in Turkish University Students

ERIC Educational Resources Information Center

Sahranç, Ümit

2015-01-01

The purpose of this study is to examine the predictive role of self-compassion on psychological entitlement. Participants were 331 university students (205 women, 126 men, M age = 20.5 years.). In this study, the Self-compassion Scale and the Psychological Entitlement Scale were used to assess self-compassion and psychological entitlement. The…

Exploring Magnetic Fields with a Compass

ERIC Educational Resources Information Center

Lunk, Brandon; Beichner, Robert

2011-01-01

A compass is an excellent classroom tool for the exploration of magnetic fields. Any student can tell you that a compass is used to determine which direction is north, but when paired with some basic trigonometry, the compass can be used to actually measure the strength of the magnetic field due to a nearby magnet or current-carrying wire. In this…

The Relationship between Self-Care Practices, Burnout, Compassion Fatigue, and Compassion Satisfaction among Professional Counselors and Counselors-in-Training

ERIC Educational Resources Information Center

Star, Katharina L.

2013-01-01

The present study examined the relationship between compassion fatigue, burnout, compassion satisfaction, and self-care among counselors and counselors-in-training. Additionally, the current study investigated if recent life changes, age, sex, race, years of experience, education level, and work/internship setting impacted counselors' and…

The Influence of Business Students' Listening Styles on Their Compassion and Self-Compassion

ERIC Educational Resources Information Center

Ramos Salazar, Leslie

2017-01-01

The aim of this study was to investigate the influence of the four listening styles of business communication students on their demonstration of compassion for others and themselves. A sample of 387 business students completed a questionnaire that inquired about their perceptions of their preferred listening style, their compassion for others, and…

Lunar rover navigation concepts

NASA Astrophysics Data System (ADS)

Burke, James D.

1993-01-01

With regard to the navigation of mobile lunar vehicles on the surface, candidate techniques are reviewed and progress of simulations and experiments made up to now are described. Progress that can be made through precursor investigations on Earth is considered. In the early seventies the problem was examined in a series of relevant tests made in the California desert. Meanwhile, Apollo rovers made short exploratory sorties and robotic Lunokhods traveled over modest distances on the Moon. In these early missions some of the required methods were demonstrated. The navigation problem for a lunar traverse can be viewed in three parts: to determine the starting point with enough accuracy to enable the desired mission; to determine the event sequence required to reach the site of each traverse objective; and to redetermine actual positions enroute. The navigator's first tool is a map made from overhead imagery. The Moon was almost completely photographed at moderate resolution by spacecraft launched in the sixties, but that data set provides imprecise topographic and selenodetic information. Therefore, more advanced orbital missions are now proposed as part of a resumed lunar exploration program. With the mapping coverage expected from such orbiters, it will be possible to use a combination of visual landmark navigation and external radio and optical references (Earth and Sun) to achieve accurate surface navigation almost everywhere on the near side of the Moon. On the far side and in permanently dark polar areas, there are interesting exploration targets where additional techniques will have to be used.

Self-Compassion and Relationship Maintenance: The Moderating Roles of Conscientiousness and Gender

PubMed Central

Baker, Levi; McNulty, James K.

2010-01-01

Should intimates respond to their interpersonal mistakes with self-criticism or with self-compassion? Although it is reasonable to expect self-compassion to benefit relationships by promoting self-esteem, it is also reasonable to expect self-compassion to hurt relationships by removing intimates’ motivation to correct their interpersonal mistakes. Two correlational studies, 1 experiment, and 1 longitudinal study demonstrated that whether self-compassion helps or hurts relationships depends on the presence versus absence of dispositional sources of the motivation to correct interpersonal mistakes. Among men, the implications of self-compassion were moderated by conscientiousness. Among men high in conscientiousness, self-compassion was associated with greater motivation to correct interpersonal mistakes (Studies 1 and 3), observations of more-constructive problem-solving behaviors (Study 2), reports of more accommodation (Study 3), and fewer declines in marital satisfaction that were mediated by decreases in interpersonal problem severity (Study 4); among men low in conscientiousness, self-compassion was associated with these outcomes in the opposite direction. Among women, in contrast, likely because women are inherently more motivated than men to preserve their relationships for cultural and/or biological reasons, self-compassion was never harmful to the relationship. Instead, women’s self-compassion was positively associated with the motivation to correct their interpersonal mistakes (Study 1) and changes in relationship satisfaction (Study 4), regardless of conscientiousness. Accordingly, theoretical descriptions of the implications of self-promoting thoughts for relationships may be most complete to the extent that they consider the presence versus absence of other sources of the motivation to correct interpersonal mistakes. PMID:21280964

Compassion training in healthcare: what are patients' perspectives on training healthcare providers?

PubMed

Sinclair, Shane; Torres, Mia-Bernadine; Raffin-Bouchal, Shelley; Hack, Thomas F; McClement, Susan; Hagen, Neil A; Chochinov, Harvey M

2016-07-11

The purpose of this qualitative study was to investigate advanced cancer patients' perspectives on the importance, feasibility, teaching methods, and issues associated with training healthcare providers in compassionate care. This study utilized grounded theory, a qualitative research method, to develop an empirical understanding of compassion education rooted in direct patient reports. Audio-recorded semi-structured interviews were conducted to obtain an in-depth understanding of compassion training from the perspectives of hospitalized advanced cancer patients (n = 53). Data were analyzed in accordance with grounded theory to determine the key elements of the underlying theory. Three overarching categories and associated themes emerged from the data: compassion aptitude, cultivating compassion, and training methods. Participants spoke of compassion as an innate quality embedded in the character of learners prior to their healthcare training, which could be nurtured through experiential learning and reflective practices. Patients felt that the innate qualities that learners possessed at baseline were further fashioned by personal and practice experiences, and vocational motivators. Participants also provided recommendations for compassion training, including developing an interpersonal relationship with patients, seeing the patient as a person, and developing a human connection. Teaching methods that patients suggested in compassion training included patient-centered communication, self-reflection exercises, and compassionate role modeling. This study provides insight on compassion training for both current and future healthcare providers, from the perspectives of the end recipients of healthcare provider training - patients. Developing a theoretical base for patient centred, evidence-informed, compassion training is a crucial initial step toward the further development of this core healthcare competency.

Coordinating compass-based and nest-based flight directions during bumblebee learning and return flights.

PubMed

Collett, Thomas S; de Ibarra, Natalie Hempel; Riabinina, Olena; Philippides, Andrew

2013-03-15

Bumblebees tend to face their nest over a limited range of compass directions when learning the nest's location on departure and finding it on their approach after foraging. They thus obtain similar views of the nest and its surroundings on their learning and return flights. How do bees coordinate their flights relative to nest-based and compass-based reference frames to get such similar views? We show, first, that learning and return flights contain straight segments that are directed along particular compass bearings, which are independent of the orientation of a bee's body. Bees are thus free within limits to adjust their viewing direction relative to the nest, without disturbing flight direction. Second, we examine the coordination of nest-based and compass-based control during likely information gathering segments of these flights: loops during learning flights and zigzags on return flights. We find that bees tend to start a loop or zigzag when flying within a restricted range of compass directions and to fly towards the nest and face it after a fixed change in compass direction, without continuous interactions between their nest-based and compass-based directions of flight. A preferred trajectory of compass-based flight over the course of a motif, combined with the tendency of the bees to keep their body oriented towards the nest automatically narrows the range of compass directions over which bees view the nest. Additionally, the absence of interactions between the two reference frames allows loops and zigzags to have a stereotyped form that can generate informative visual feedback.

Barriers to self-compassion for female survivors of childhood maltreatment: The roles of fear of self-compassion and psychological inflexibility.

PubMed

Boykin, Derrecka M; Himmerich, Sara J; Pinciotti, Caitlin M; Miller, Lindsay M; Miron, Lynsey R; Orcutt, Holly K

2018-02-01

Preliminary evidence has demonstrated the benefits of targeting self-compassion in the treatment of posttraumatic stress disorder (PTSD). However, survivors of childhood maltreatment may present with unique challenges that compromise the effectiveness of these and other PTSD treatments. Specifically, childhood maltreatment victims often exhibit a marked fear and active resistance of self-kindness and warmth (i.e., fear of self-compassion). Victims may also attempt to control distressing internal experiences in a way that hinders engagement in value-based actions (i.e., psychological inflexibility). Research suggests that psychological inflexibility exacerbates the negative effects of fear of self-compassion. The present study expanded on previous research by examining the relations among childhood maltreatment, fear of self-compassion, psychological inflexibility, and PTSD symptom severity in 288 college women. As expected, moderate to severe levels of childhood maltreatment were associated with greater fear of self-compassion, psychological inflexibility, and PTSD symptom severity compared to minimal or no childhood maltreatment. A mediation analysis showed that childhood maltreatment had a significant indirect effect on PTSD symptom severity via fear of self-compassion, although a conditional process analysis did not support psychological inflexibility as a moderator of this indirect effect. A post hoc multiple mediator analysis showed a significant indirect effect of childhood maltreatment on PTSD symptom severity via psychological inflexibility, but not fear of self-compassion. These findings highlight the importance of addressing fear of self-compassion and psychological inflexibility as barriers to treatment for female survivors of childhood maltreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predictors of Compassion Fatigue and Compassion Satisfaction in Acute Care Nurses.

PubMed

Kelly, Lesly; Runge, Jody; Spencer, Christina

2015-11-01

To examine compassion fatigue and compassion satisfaction in acute care nurses across multiple specialties in a hospital-based setting. A cross-sectional electronic survey design was used to collect data from direct care nurses in a 700-bed, quaternary care, teaching facility in the southwestern United States. A total of 491 direct care registered nurses completed a survey measuring their professional quality of life (burnout, secondary traumatic stress, and compassion satisfaction). Analysis was conducted to assess for differences between demographics, specialties, job satisfaction, and intent to leave their current position. Significant predictors of burnout included lack of meaningful recognition, nurses with more years of experience, and nurses in the "Millennial" generation (ages 21-33 years). Receiving meaningful recognition, higher job satisfaction, nurses in the "Baby Boomer" generation (ages 50-65 years), and nurses with fewer years of experience significantly predicted compassion satisfaction. No significant differences were noted across nurse specialties, units, or departments. This study adds to the literature the impact meaningful recognition may have on compassion satisfaction and fatigue. Our findings provide a potential explanation for the lack of retention of nurses in the millennial generation who leave their positions with limited years of experience. Based on our research, meaningful recognition may increase compassion satisfaction, positively impact retention, and elevate job satisfaction. Compassion fatigue in nurses has clear implications for nursing retention and the quality of care. Organizations willing to invest in reducing compassion fatigue have the potential to improve financial savings by reducing turnover and adverse events associated with burnout. © 2015 Sigma Theta Tau International.

Sympathy, empathy, and compassion: A grounded theory study of palliative care patients' understandings, experiences, and preferences.

PubMed

Sinclair, Shane; Beamer, Kate; Hack, Thomas F; McClement, Susan; Raffin Bouchal, Shelley; Chochinov, Harvey M; Hagen, Neil A

2017-05-01

Compassion is considered an essential element in quality patient care. One of the conceptual challenges in healthcare literature is that compassion is often confused with sympathy and empathy. Studies comparing and contrasting patients' perspectives of sympathy, empathy, and compassion are largely absent. The aim of this study was to investigate advanced cancer patients' understandings, experiences, and preferences of "sympathy," "empathy," and "compassion" in order to develop conceptual clarity for future research and to inform clinical practice. Data were collected via semi-structured interviews and then independently analyzed by the research team using the three stages and principles of Straussian grounded theory. Data were collected from 53 advanced cancer inpatients in a large urban hospital. Constructs of sympathy, empathy, and compassion contain distinct themes and sub-themes. Sympathy was described as an unwanted, pity-based response to a distressing situation, characterized by a lack of understanding and self-preservation of the observer. Empathy was experienced as an affective response that acknowledges and attempts to understand individual's suffering through emotional resonance. Compassion enhanced the key facets of empathy while adding distinct features of being motivated by love, the altruistic role of the responder, action, and small, supererogatory acts of kindness. Patients reported that unlike sympathy, empathy and compassion were beneficial, with compassion being the most preferred and impactful. Although sympathy, empathy, and compassion are used interchangeably and frequently conflated in healthcare literature, patients distinguish and experience them uniquely. Understanding patients' perspectives is important and can guide practice, policy reform, and future research.

Self-compassion and relationship maintenance: the moderating roles of conscientiousness and gender.

PubMed

Baker, Levi R; McNulty, James K

2011-05-01

Should intimates respond to their interpersonal mistakes with self-criticism or with self-compassion? Although it is reasonable to expect self-compassion to benefit relationships by promoting self-esteem, it is also reasonable to expect self-compassion to hurt relationships by removing intimates' motivation to correct their interpersonal mistakes. Two correlational studies, 1 experiment, and 1 longitudinal study demonstrated that whether self-compassion helps or hurts relationships depends on the presence versus absence of dispositional sources of the motivation to correct interpersonal mistakes. Among men, the implications of self-compassion were moderated by conscientiousness. Among men high in conscientiousness, self-compassion was associated with greater motivation to correct interpersonal mistakes (Studies 1 and 3), observations of more constructive problem-solving behaviors (Study 2), reports of more accommodation (Study 3), and fewer declines in marital satisfaction that were mediated by decreases in interpersonal problem severity (Study 4); among men low in conscientiousness, self-compassion was associated with these outcomes in the opposite direction. Among women, in contrast, likely because women are inherently more motivated than men to preserve their relationships for cultural and/or biological reasons, self-compassion was never harmful to the relationship. Instead, women's self-compassion was positively associated with the motivation to correct their interpersonal mistakes (Study 1) and changes in relationship satisfaction (Study 4), regardless of conscientiousness. Accordingly, theoretical descriptions of the implications of self-promoting thoughts for relationships may be most complete to the extent that they consider the presence versus absence of other sources of the motivation to correct interpersonal mistakes. (c) 2011 APA, all rights reserved.

Solar Eruptions, CMEs and Space Weather

NASA Technical Reports Server (NTRS)

Gopalswamy, Nat

2011-01-01

Coronal mass ejections (CMEs) are large-scale magnetized plasma structures ejected from the Sun and propagate far into the interplanetary medium. CMEs represent energy output from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. The plasma clouds can drive shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. The plasma clouds also arrive at Earth in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currents that can disrupt power grids, railroads, and underground pipelines. This lecture presents an overview of the origin, propagation, and geospace consequences of solar storms.

Oncologist burnout and compassion fatigue: investigating time pressure at work as a predictor and the mediating role of work-family conflict.

PubMed

Kleiner, Sibyl; Wallace, Jean E

2017-09-11

Oncologists are at high risk of poor mental health. Prior research has focused on burnout, and has identified heavy workload as a key predictor. Compassion fatigue among physicians has generally received less attention, although medical specialties such as oncology may be especially at risk of compassion fatigue. We contribute to research by identifying predictors of both burnout and compassion fatigue among oncologists. In doing so, we distinguish between quantitative workload (e.g., work hours) and subjective work pressure, and test whether work-family conflict mediates the relationships between work pressure and burnout or compassion fatigue. In a cross-sectional study, oncologists from across Canada (n = 312) completed questionnaires assessing burnout, compassion fatigue, workload, time pressure at work, work-family conflict, and other personal, family, and occupational characteristics. Analyses use Ordinary Least Squares regression. Subjective time pressure at work is a key predictor of both burnout and compassion fatigue. Our results also show that work-family conflict fully mediates these relationships. Overall, the models explain more of the variation in burnout as compared to compassion fatigue. Our study highlights the need to consider oncologists' subjective time pressure, in addition to quantitative workload, in interventions to improve mental health. The findings also highlight a need to better understand additional predictors of compassion fatigue.

Examining the Factors of Self-Compassion Scale with Canonical Commonality Analysis: Syrian Sample

ERIC Educational Resources Information Center

Ozdemir, Burhanettin; Seef, Nesrin

2017-01-01

Purpose of Study: The purpose of this study is to examine the psychological structure of self-compassion and to determine the relationship between the sub-dimensions (or factors) of the self-compassion-scale and the contribution of each factor to the construct. Although the self-compassion scale has been commonly used in the area of psychology,…

Compassion satisfaction, compassion fatigue, anxiety, depression and stress in registered nurses in Australia: phase 2 results.

PubMed

Drury, Vicki; Craigie, Mark; Francis, Karen; Aoun, Samar; Hegney, Desley G

2014-05-01

This is the first two-phase Australian study to explore the factors impacting upon compassion satisfaction, compassion fatigue, anxiety, depression and stress and to describe the strategies nurses use to build compassion satisfaction into their working lives. Compassion fatigue has been found to impact on job satisfaction, the quality of patient care and retention within nursing. This study provides new knowledge on the influences of anxiety, stress and depression and how they relate to compassion satisfaction and compassion fatigue. In Phase 2 of the study, 10 nurses from Phase 1 of the study participated in individual interviews and a focus group. A semi-structured interview schedule guided the conversations with the participants. Data analysis resulted in seven main themes: social networks and support;infrastructure and support; environment and lifestyle; learning; leadership; stress; and suggestions to build psychological wellness in nurses. Findings suggest that a nurse’s capacity to cope is enhanced through strong social and collegial support, infrastructure that supports the provision of quality nursing care and positive affirmation. These concepts are strongly linked to personal resilience. for nursing management These findings support the need for management to develop appropriate interventions to build resilience in nurses.

Stomaching rejection: Self-compassion and self-esteem moderate the impact of daily social rejection on restrictive eating behaviours among college women.

PubMed

Beekman, Janine B; Stock, Michelle L; Howe, George W

2017-11-01

The present study examined whether having high self-esteem or a self-compassionate perspective help mitigate the impact of daily social rejection on negative affect and restrictive eating behaviours. Following a baseline survey assessing self-esteem and self-compassion, 121 college women completed online daily diaries for one week. Negative affect and restrictive eating behaviours. On days when women reported more rejection, they also reported higher restrictive eating behaviours and greater negative affect. Effects were moderated by self-esteem and self-compassion, such that the lower participants were in self-esteem or self-compassion, the stronger the positive relation between rejection and negative affect and restrictive eating. However, only the common humanity/isolation dimension of self-compassion significantly moderated daily effects of rejection when controlling for self-esteem. Mediated moderation results reveal different mechanisms by which self-esteem and self-compassion buffer against rejections' effects on affect and restrictive eating. Self-compassion and self-esteem influence the complex impact that social rejection has on affect and restrictive eating. More than other dimensions of self-compassion or self-esteem, remembering one's common humanity can result in a healthier response to social rejection.