On the use of magnets to disrupt the physiological compass of birds.

PubMed

Wang, K; Mattern, E; Ritz, T

2006-10-04

Behavioral researchers have attached magnets to birds during orientation experiments, assuming that such magnets will disrupt their ability to obtain magnetic information. Here, we investigate the effect of an attached magnet on the ability to derive directional information from a radical-pair based compass mechanism. We outline in some detail the geometrical symmetries that would allow a bird to identify magnetic directions in a radical-pair based compass. We show that the artificial field through an attached magnet will quickly disrupt the birds' ability to distinguish pole-ward from equator-ward headings, but that much stronger fields are necessary to disrupt their ability to detect the magnetic axis. Together with estimates of the functional limits of a radical-pair based compass, our calculations suggest that artificial fields of comparable size to the geomagnetic field are not generally sufficient to render a radical-pair based compass non-functional.

Magnetic Orientation in Birds and Other Animals

NASA Astrophysics Data System (ADS)

Wiltschko, Wolfgang

The use of the geomagnetic field for compass orientation is widespread among animals, with two types of magnetic compass mechanisms described: an shape inclination compass in birds, turtles and salamanders and a shape polarity compass in arthropods, fishes and mammals. Additionally, some vertebrates appear to derive positional information from the total intensity and/or inclination of the geomagnetic field. For magnetoreception by animals, two models are currently discussed, the shape Radical Pair model assuming light-dependent processes by specialized photopigments, and the shape Magnetite hypothesis proposing magnetoreception by crystals of magnetite, Fe304. Behavioral experiments with migratory birds, testing them under monochromatic lights and subjecting them to a brief, strong pulse that could reverse the magnetization of magnetite particles, produced evidence for both mechanisms. However, monochromatic lights affect old, experienced and young birds alike, whereas the pulse affects only experienced birds, leaving young, inexperienced birds unaffected. These observations suggest that a radical pair mechanism provides birds with directional information for their innate magnetic compass and a magnetite-based mechanism possibly mediates information about total intensity for indicating position.

Avian magnetic compass can be tuned to anomalously low magnetic intensities.

PubMed

Winklhofer, Michael; Dylda, Evelyn; Thalau, Peter; Wiltschko, Wolfgang; Wiltschko, Roswitha

2013-07-22

The avian magnetic compass works in a fairly narrow functional window around the intensity of the local geomagnetic field, but adjusts to intensities outside this range when birds experience these new intensities for a certain time. In the past, the geomagnetic field has often been much weaker than at present. To find out whether birds can obtain directional information from a weak magnetic field, we studied spontaneous orientation preferences of migratory robins in a 4 µT field (i.e. a field of less than 10 per cent of the local intensity of 47 µT). Birds can adjust to this low intensity: they turned out to be disoriented under 4 µT after a pre-exposure time of 8 h to 4 µT, but were able to orient in this field after a total exposure time of 17 h. This demonstrates a considerable plasticity of the avian magnetic compass. Orientation in the 4 µT field was not affected by local anaesthesia of the upper beak, but was disrupted by a radiofrequency magnetic field of 1.315 MHz, 480 nT, suggesting that a radical-pair mechanism still provides the directional information in the low magnetic field. This is in agreement with the idea that the avian magnetic compass may have developed already in the Mesozoic in the common ancestor of modern birds.

Avian magnetic compass can be tuned to anomalously low magnetic intensities

PubMed Central

Winklhofer, Michael; Dylda, Evelyn; Thalau, Peter; Wiltschko, Wolfgang; Wiltschko, Roswitha

2013-01-01

The avian magnetic compass works in a fairly narrow functional window around the intensity of the local geomagnetic field, but adjusts to intensities outside this range when birds experience these new intensities for a certain time. In the past, the geomagnetic field has often been much weaker than at present. To find out whether birds can obtain directional information from a weak magnetic field, we studied spontaneous orientation preferences of migratory robins in a 4 µT field (i.e. a field of less than 10 per cent of the local intensity of 47 µT). Birds can adjust to this low intensity: they turned out to be disoriented under 4 µT after a pre-exposure time of 8 h to 4 µT, but were able to orient in this field after a total exposure time of 17 h. This demonstrates a considerable plasticity of the avian magnetic compass. Orientation in the 4 µT field was not affected by local anaesthesia of the upper beak, but was disrupted by a radiofrequency magnetic field of 1.315 MHz, 480 nT, suggesting that a radical-pair mechanism still provides the directional information in the low magnetic field. This is in agreement with the idea that the avian magnetic compass may have developed already in the Mesozoic in the common ancestor of modern birds. PMID:23720547

Teaching Basic Geographical Skills: Map and Compass Activities.

ERIC Educational Resources Information Center

Trussell, Margaret Edith

1986-01-01

Presents a unit on map and compass activities which introduces compass direction, magnetic declination and conversion of map measurement to familiar units. Requires four, one-hour class meetings and may be followed by a half-day orienteering activity. (Author/JDH)

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.

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.

Weak Broadband Electromagnetic Fields are More Disruptive to Magnetic Compass Orientation in a Night-Migratory Songbird (Erithacus rubecula) than Strong Narrow-Band Fields

PubMed Central

Schwarze, Susanne; Schneider, Nils-Lasse; Reichl, Thomas; Dreyer, David; Lefeldt, Nele; Engels, Svenja; Baker, Neville; Hore, P. J.; Mouritsen, Henrik

2016-01-01

Magnetic compass orientation in night-migratory songbirds is embedded in the visual system and seems to be based on a light-dependent radical pair mechanism. Recent findings suggest that both broadband electromagnetic fields ranging from ~2 kHz to ~9 MHz and narrow-band fields at the so-called Larmor frequency for a free electron in the Earth’s magnetic field can disrupt this mechanism. However, due to local magnetic fields generated by nuclear spins, effects specific to the Larmor frequency are difficult to understand considering that the primary sensory molecule should be organic and probably a protein. We therefore constructed a purpose-built laboratory and tested the orientation capabilities of European robins in an electromagnetically silent environment, under the specific influence of four different oscillating narrow-band electromagnetic fields, at the Larmor frequency, double the Larmor frequency, 1.315 MHz or 50 Hz, and in the presence of broadband electromagnetic noise covering the range from ~2 kHz to ~9 MHz. Our results indicated that the magnetic compass orientation of European robins could not be disrupted by any of the relatively strong narrow-band electromagnetic fields employed here, but that the weak broadband field very efficiently disrupted their orientation. PMID:27047356

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

The magnetic map sense and its use in fine-tuning the migration programme of birds.

PubMed

Heyers, D; Elbers, D; Bulte, M; Bairlein, F; Mouritsen, H

2017-07-01

The Earth's magnetic field is one of several natural cues, which migratory birds can use to derive directional ("compass") information for orientation on their biannual migratory journeys. Moreover, magnetic field effects on prominent aspects of the migratory programme of birds, such as migratory restlessness behaviour, fuel deposition and directional orientation, implicate that geomagnetic information can also be used to derive positional ("map") information. While the magnetic "compass" in migratory birds is likely to be based on radical pair-forming molecules embedded in their visual system, the sensory correlates underlying a magnetic "map" sense currently remain elusive. Behavioural, physiological and neurobiological findings indicate that the sensor is most likely innervated by the ophthalmic branch of the trigeminal nerve and based on magnetic iron particles. Information from this unknown sensor is neither necessary nor sufficient for a functional magnetic compass, but instead could contribute important components of a multifactorial "map" for global positioning. Positional information could allow migratory birds to make vitally important dynamic adaptations of their migratory programme at any relevant point during their journeys.

Lateralization of magnetic compass orientation in a migratory bird

NASA Astrophysics Data System (ADS)

Wiltschko, Wolfgang; Traudt, Joachim; Güntürkün, Onur; Prior, Helmut; Wiltschko, Roswitha

2002-10-01

Lateralization of brain functions, once believed to be a human characteristic, has now been found to be widespread among vertebrates. In birds, asymmetries of visual functions are well studied, with each hemisphere being specialized for different tasks. Here we report lateralized functions of the birds' visual system associated with magnetoperception, resulting in an extreme asymmetry of sensing the direction of the magnetic field. We found that captive migrants tested in cages with the magnetic field as the only available orientation cue were well oriented in their appropriate migratory direction when using their right eye only, but failed to show a significant directional preference when using their left eye. This implies that magnetoreception for compass orientation, assumed to take place in the eyes alongside the visual processes, is strongly lateralized, with a marked dominance of the right eye/left brain hemisphere.

Light-dependent magnetoreception: orientation behaviour of migratory birds under dim red light.

PubMed

Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Wiltschko, Wolfgang

2008-10-01

Magnetic compass orientation in migratory birds has been shown to be based on radical pair processes and to require light from the short wavelength part of the spectrum up to 565 nm Green. Under dim red light of 645 nm wavelength and 1 mW m(-2) intensity, Australian silvereyes and European robins showed a westerly tendency that did not change between spring and autumn, identifying it as a 'fixed direction' response. A thorough analysis revealed that this orientation did not involve the inclination compass, but was a response based on the polarity of the magnetic field. Furthermore, in contrast to the orientation under short-wavelength light, it could be disrupted by local anaesthesia of the upper beak where iron-containing receptors are located, indicating that it is controlled by these receptors. The similarity of the response under dim red light to the response in total darkness suggests that the two responses may be identical. These findings indicate that the observed 'fixed direction' response under dim red light is fundamentally different from the normal compass orientation, which is based on radical pair processes.

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.

28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS STAND FOR DETERMINING CORE'S FIELD ORIENTATION; INSECTICIDE DISPENSER MODIFIED TO LUBRICATE CORE DRILLING PROCESS. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

Night-Migratory Songbirds Possess a Magnetic Compass in Both Eyes

PubMed Central

Lefeldt, Nele; Prior, Helmut; Mouritsen, Henrik

2012-01-01

Previous studies on European robins, Erithacus rubecula, and Australian silvereyes, Zosterops lateralis, had suggested that magnetic compass information is being processed only in the right eye and left brain hemisphere of migratory birds. However, recently it was demonstrated that both garden warblers, Sylvia borin, and European robins have a magnetic compass in both eyes. These results raise the question if the strong lateralization effect observed in earlier experiments might have arisen from artifacts or from differences in experimental conditions rather than reflecting a true all-or-none lateralization of the magnetic compass in European robins. Here we show that (1) European robins having only their left eye open can orient in their seasonally appropriate direction both during autumn and spring, i.e. there are no strong lateralization differences between the outward journey and the way home, that (2) their directional choices are based on the standard inclination compass as they are turned 180° when the inclination is reversed, and that (3) the capability to use the magnetic compass does not depend on monocular learning or intraocular transfer as it is already present in the first tests of the birds with only one eye open. PMID:22984416

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

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.

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

Probing a chemical compass: novel variants of low-frequency reaction yield detected magnetic resonance.

PubMed

Maeda, Kiminori; Storey, Jonathan G; Liddell, Paul A; Gust, Devens; Hore, P J; Wedge, C J; Timmel, Christiane R

2015-02-07

We present a study of a carotenoid-porphyrin-fullerene triad previously shown to function as a chemical compass: the photogenerated carotenoid-fullerene radical pair recombines at a rate sensitive to the orientation of an applied magnetic field. To characterize the system we develop a time-resolved Low-Frequency Reaction Yield Detected Magnetic Resonance (tr-LF-RYDMR) technique; the effect of varying the relative orientation of applied static and 36 MHz oscillating magnetic fields is shown to be strongly dependent on the strength of the oscillating magnetic field. RYDMR is a diagnostic test for involvement of the radical pair mechanism in the magnetic field sensitivity of reaction rates or yields, and has previously been applied in animal behavioural experiments to verify the involvement of radical-pair-based intermediates in the magnetic compass sense of migratory birds. The spectroscopic selection rules governing RYDMR are well understood at microwave frequencies for which the so-called 'high-field approximation' is valid, but at lower frequencies different models are required. For example, the breakdown of the rotating frame approximation has recently been investigated, but less attention has so far been given to orientation effects. Here we gain physical insights into the interplay of the different magnetic interactions affecting low-frequency RYDMR experiments performed in the challenging regime in which static and oscillating applied magnetic fields as well as internal electron-nuclear hyperfine interactions are of comparable magnitude. Our observations aid the interpretation of existing RYDMR-based animal behavioural studies and will inform future applications of the technique to verify and characterize further the biological receptors involved in avian magnetoreception.

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.

Disruption of Magnetic Compass Orientation in Migratory Birds by Radiofrequency Electromagnetic Fields.

PubMed

Hiscock, Hamish G; Mouritsen, Henrik; Manolopoulos, David E; Hore, P J

2017-10-03

The radical-pair mechanism has been put forward as the basis of the magnetic compass sense of migratory birds. Some of the strongest supporting evidence has come from behavioral experiments in which birds exposed to weak time-dependent magnetic fields lose their ability to orient in the geomagnetic field. However, conflicting results and skepticism about the requirement for abnormally long quantum coherence lifetimes have cast a shroud of uncertainty over these potentially pivotal studies. Using a recently developed computational approach, we explore the effects of various radiofrequency magnetic fields on biologically plausible radicals within the theoretical framework of radical-pair magnetoreception. We conclude that the current model of radical-pair magnetoreception is unable to explain the findings of the reported behavioral experiments. Assuming that an unknown mechanism amplifies the predicted effects, we suggest experimental conditions that have the potential to distinguish convincingly between the two distinct families of radical pairs currently postulated as magnetic compass sensors. We end by making recommendations for experimental protocols that we hope will increase the chance that future experiments can be independently replicated. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

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.

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.

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

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...

Glass eels (Anguilla anguilla) have a magnetic compass linked to the tidal cycle

PubMed Central

Cresci, Alessandro; Paris, Claire B.; Durif, Caroline M. F.; Shema, Steven; Bjelland, Reidun M.; Skiftesvik, Anne Berit; Browman, Howard I.

2017-01-01

The European eel (Anguilla anguilla) has one of the longest migrations in the animal kingdom. It crosses the Atlantic Ocean twice during its life history, migrating between the spawning area in the Sargasso Sea and Europe, where it is widely distributed. The leptocephalus larvae drift with the Gulf Stream and other currents for more than a year and metamorphose into glass eels when they arrive on the continental shelf and move toward coastal areas. The mechanisms underlying glass eel orientation toward the coast and into freshwater systems are poorly known. However, anguillid eels, including the glass eel life stage, have a geomagnetic sense, suggesting the possibility that they use Earth’s magnetic field to orient toward the coast. To test this hypothesis, we used a unique combination of laboratory tests and in situ behavioral observations conducted in a drifting circular arena. Most (98%) of the glass eels tested in the sea exhibited a preferred orientation that was related to the tidal cycle. Seventy-one percent of the same eels showed the same orientation during ebb tide when tested in the laboratory under a manipulated simulated magnetic field in the absence of any other cue. These results demonstrate that glass eels use a magnetic compass for orientation and suggest that this magnetic orientation system is linked to a circatidal rhythm. PMID:28630895

Magnetic anisotropy and organization of nanoparticles in heads and antennae of neotropical leaf-cutter ants, Atta colombica

USDA-ARS?s Scientific Manuscript database

Oriented magnetic nanoparticles have been suggested as a good candidate for a magnetic sensor in ants. Behavioral evidence for a magnetic compass in Neotropical leafcutter ants, Atta colombica (Formicidae: Attini), motivated a study of the arrangement of magnetic particles in the ants’ four major bo...

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.

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

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.

Compass magnetoreception in birds arising from photo-induced radical pairs in rotationally disordered cryptochromes

PubMed Central

Lau, Jason C. S.; Rodgers, Christopher T.; Hore, P. J.

2012-01-01

According to the radical pair model, the magnetic compass sense of migratory birds relies on photochemical transformations in the eye to detect the direction of the geomagnetic field. Magnetically sensitive radical pairs are thought to be generated in cryptochrome proteins contained in magnetoreceptor cells in the retina. A prerequisite of the current model is for some degree of rotational ordering of both the cryptochromes within the cells and of the cells within the retina so that the directional responses of individual molecules do not average to zero. Here, it is argued that anisotropic distributions of radical pairs can be generated by the photoselection effects that arise from the directionality of the light entering the eye. Light-induced rotational order among the transient radical pairs rather than intrinsic ordering of their molecular precursors is seen as the fundamental condition for a magnetoreceptor cell to exhibit an anisotropic response. A theoretical analysis shows that a viable compass magnetoreceptor could result from randomly oriented cryptochromes contained in randomly oriented cells distributed around the retina. PMID:22977104

Assessment of the precision of smart phones and tablets for measurement of planar orientations: A case study

NASA Astrophysics Data System (ADS)

Novakova, Lucie; Pavlis, Terry L.

2017-04-01

Although paper and pencil approaches to geological mapping continue, digital mapping tools are being increasing implemented in field geology. Of particular note is the use of an electronic compass/inclinometer built into tablets and smartphones for obtaining orientation data where an important question is the reliability of these digital devices relative to conventional, analogue compass/inclinometers. This paper deals with this question through detailed tests of two android devices: an Honor 3C smartphone and a Lenovo B8080-F tablet. In order to evaluate potential electronic noise effects the devices were tested in two modes, standard and airplane. Over 14,000 readings from the sensors were collected to evaluate the stability of the sensor's readings and showed that the magnetic sensor in the tablet was unacceptably unstable. Seven geological compass applications were installed on the Honor 3C smartphone and tested against the analogue Freiberg geological compass in a field experiment. During the experiment 25 fractures varying in azimuth and dip were measured using both devices. A high level of disagreement was observed with discrepancies as high as 80° with azimuthal errors dominant. Analysis of the time series in the data suggest the source of the problem was instability in the magnetic sensor for the smartphone, despite the fact the device passed the initial stability test. Although only two devices were studied these data indicate care must be taken to evaluate compass accuracy on these devices.

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.

Interaction of magnetite-based receptors in the beak with the visual system underlying 'fixed direction' responses in birds

PubMed Central

2010-01-01

Background European robins, Erithacus rubecula, show two types of directional responses to the magnetic field: (1) compass orientation that is based on radical pair processes and lateralized in favor of the right eye and (2) so-called 'fixed direction' responses that originate in the magnetite-based receptors in the upper beak. Both responses are light-dependent. Lateralization of the 'fixed direction' responses would suggest an interaction between the two magnetoreception systems. Results Robins were tested with either the right or the left eye covered or with both eyes uncovered for their orientation under different light conditions. With 502 nm turquoise light, the birds showed normal compass orientation, whereas they displayed an easterly 'fixed direction' response under a combination of 502 nm turquoise with 590 nm yellow light. Monocularly right-eyed birds with their left eye covered were oriented just as they were binocularly as controls: under turquoise in their northerly migratory direction, under turquoise-and-yellow towards east. The response of monocularly left-eyed birds differed: under turquoise light, they were disoriented, reflecting a lateralization of the magnetic compass system in favor of the right eye, whereas they continued to head eastward under turquoise-and-yellow light. Conclusion 'Fixed direction' responses are not lateralized. Hence the interactions between the magnetite-receptors in the beak and the visual system do not seem to involve the magnetoreception system based on radical pair processes, but rather other, non-lateralized components of the visual system. PMID:20707905

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

Possible steps in the evolutionary development of bird navigation

NASA Technical Reports Server (NTRS)

Bellrose, F. C.

1972-01-01

Hypotheses are presented to explain the evolutionary development of navigational ability in migratory birds. Areas of discussion to describe the possible techniques are: (1) sun compass, (2) bicoordinate navigation, (3) star compass, (4) wind cues, (5) earth magnetic field, and (6) landscape features. It is concluded that landscape is the single most important cue for orientation of nonmigratory birds. The long range migratory birds appear to use a combination of cues with the relative importance of the cue dependent upon the species of the bird involved.

Interactions between the visual and the magnetoreception system: different effects of bichromatic light regimes on the directional behavior of migratory birds.

PubMed

Wiltschko, Roswitha; Dehe, Lars; Gehring, Dennis; Thalau, Peter; Wiltschko, Wolfgang

2013-01-01

When magnetic compass orientation of migratory robins was tested, the birds proved well oriented under low intensity monochromatic light of shorter wavelengths up to 565 nm green; from 583 nm yellow onward, they were disoriented. In the present study, we tested robins under bichromatic lights composed (1) of 424 nm blue and 565 nm green and (2) of 565 nm green and 583 nm yellow at two intensities. Under dim blue-green light with a total quantal flux of ca. 8 × 10(15)quanta/sm(2), the birds were well oriented in their migratory direction by their inclination compass; under blue-green light of twice this intensity, their orientation became axial. In both cases, the magnetic directional information was mediated by the radical pair processes in the eye. When green and yellow light were combined, however, the nature of the behavior changed. Under green-yellow light of the higher intensity, the birds showed a 'fixed direction' response that was polar, no longer controlled by the normal inclination compass; under dim green-yellow light, the response became axial. Under these two light conditions, the respective directional information was mediated by the magnetite-based receptors in the skin of the upper beak. Apparently, yellow light leads to a change from one magnetoreception system to the other. How this change is effected is still unknown; it appears to reflect complex interactions between the visual and the two magnetoreception systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

A low-noise MEMS accelerometer for unattended ground sensor applications

NASA Astrophysics Data System (ADS)

Speller, Kevin E.; Yu, Duli

2004-09-01

A low-noise micro-machined servo accelerometer has been developed for use in Unattended Ground Sensors (UGS). Compared to conventional coil-and-magnet based velocity transducers, this Micro-Electro-Mechanical System (MEMS) accelerometer offers several key benefits for battlefield monitoring. Many UGS require a compass to determine deployment orientation with respect to magnetic North. This orientation information is critical for determining the bearing of incoming signals. Conventional sensors with sensing technology based on a permanent magnet can cause interference with a compass when used in close proximity. This problem is solved with a MEMS accelerometer which does not require any magnetic materials. Frequency information below 10 Hz is valuable for identification of signal sources. Conventional seismometers used in UGS are typically limited in frequency response from 20 to 200 Hz. The MEMS accelerometer has a flat frequency response from DC to 5 kHz. The wider spectrum of signals received improves detection, classification and monitoring on the battlefield. The DC-coupled output of the MEMS accelerometer also has the added benefit of providing tilt orientation data for the deployed UGS. Other performance parameters of the MEMS accelerometer that are important to UGS such as size, weight, shock survivability, phase response, distortion, and cross-axis rejection will be discussed. Additionally, field test data from human footsteps recorded with the MEMS accelerometer will be presented.

Rapid learning of magnetic compass direction by C57BL/6 mice in a 4-armed 'plus' water maze.

PubMed

Phillips, John B; Youmans, Paul W; Muheim, Rachel; Sloan, Kelly A; Landler, Lukas; Painter, Michael S; Anderson, Christopher R

2013-01-01

Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze) have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus) water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180(°) so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1) absence of alternative directional cues (2), rotation of magnetic field alignment, and (3) electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats) have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds.

Rapid Learning of Magnetic Compass Direction by C57BL/6 Mice in a 4-Armed ‘Plus’ Water Maze

PubMed Central

Phillips, John B.; Youmans, Paul W.; Muheim, Rachel; Sloan, Kelly A.; Landler, Lukas; Painter, Michael S.; Anderson, Christopher R.

2013-01-01

Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze) have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus) water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180° so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1) absence of alternative directional cues (2), rotation of magnetic field alignment, and (3) electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats) have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds. PMID:24023673

Magnetic orientation in birds: non-compass responses under monochromatic light of increased intensity.

PubMed

Wiltschko, Wolfgang; Munro, Ursula; Ford, Hugh; Wiltschko, Roswitha

2003-10-22

Migratory Australian silvereyes (Zosterops lateralis) were tested under monochromatic light at wavelengths of 424 nm blue and 565 nm green. At a low light level of 7 x 10(15) quanta m(-2) s(-1) in the local geomagnetic field, the birds preferred their seasonally appropriate southern migratory direction under both wavelengths. Their reversal of headings when the vertical component of the magnetic field was inverted indicated normal use of the avian inclination compass. A higher light intensity of 43 x 10(15) quanta m(-2) s(-1), however, caused a fundamental change in behaviour: under bright blue, the silvereyes showed an axial tendency along the east-west axis; under bright green, they showed a unimodal preference of a west-northwesterly direction that followed a shift in magnetic north, but was not reversed by inverting the vertical component of the magnetic field. Hence it is not based on the inclination compass. The change in behaviour at higher light intensities suggests a complex interaction between at least two receptors. The polar nature of the response under bright green cannot be explained by the current models of light-dependent magnetoreception and will lead to new considerations on these receptive processes.

Behavioral evidence for a magnetic sense in the oriental armyworm, Mythimna separata

PubMed Central

Xu, Jingjing; Zhang, Yingchao; Li, Yue; Wan, Guijun; Chen, Fajun; Sword, Gregory A.; Pan, Weidong

2017-01-01

ABSTRACT Progress has been made in understanding the mechanisms underlying directional navigation in migratory insects, yet the magnetic compass involved has not been fully elucidated. Here we developed a flight simulation system to study the flight directionality of the migratory armyworm Mythimna separata in response to magnetic fields. Armyworm moths were exposed to either a 500 nT extreme weak magnetic field, 1.8 T strong magnetic field, or a deflecting magnetic field and subjected to tethered flight trials indoors in the dark. The moths were disoriented in the extreme weak magnetic field, with flight vectors that were more dispersed (variance=0.60) than in the geomagnetic field (variance=0.32). After exposure to a 1.8 T strong magnetic field, the mean flight vectors were shifted by about 105° in comparison with those in the geomagnetic field. In the deflecting magnetic field, the flight directions varied with the direction of the magnetic field, and also pointed to the same direction of the magnetic field. In the south-north magnetic field and the east-west field, the flight angles were determined to be 98.9° and 166.3°, respectively, and formed the included angles of 12.66° or 6.19° to the corresponding magnetic direction. The armyworm moths responded to the change of the intensity and direction of magnetic fields. Such results provide initial indications of the moth reliance on a magnetic compass. The findings support the hypothesis of a magnetic sense used for flight orientation in the armyworm Mythimna separata. PMID:28126710

Structural data collection with mobile devices: Accuracy, redundancy, and best practices

NASA Astrophysics Data System (ADS)

Allmendinger, Richard W.; Siron, Christopher R.; Scott, Chelsea P.

2017-09-01

Smart phones are equipped with numerous sensors that enable orientation data collection for structural geology at a rate up to an order of magnitude faster than traditional analog compasses. The rapidity of measurement enables field structural geologists, for the first time, to enjoy the benefits of data redundancy and quantitative uncertainty estimates. Recent work, however, has called into question the reliability of sensors on Android devices. We present here our experience with programming a new smart phone app from scratch, and using it and commercial apps on iOS devices along with analog compasses in a series of controlled tests and typical field use cases. Additionally, we document the relationships between iPhone measurements and visible structures in satellite, drawing on a database of 3700 iPhone measurements of coseismic surface cracks we made in northern Chile following the Mw8.1 Pisagua earthquake in 2014. By comparing phone-collected attitudes to orientations determined independently of the magnetic field, we avoid having to assume that the analog compass, which is subject to its own uncertainties, is the canonical instrument. Our results suggest that iOS devices are suitable for all but the most demanding applications as long as particular care is taken with respect to metal and electronic objects that could affect the magnetic field.

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

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.

Dark state population determines magnetic sensitivity in radical pair magnetoreception model.

PubMed

Xu, Bao-Ming; Zou, Jian

2016-03-01

What is the real role of the quantum coherence and entanglement in the radical pair (RP) compass, and what determines the singlet yield have not been fully understood. In this paper, we find that the dark states of the two-electron Zeeman energy operator (TEZE) play an important role in the RP compass. We respectively calculate the singlet yields for two initial states in this dark state basis: the coherent state and the same state just removing the dark state coherence. For the later there is neither dark state coherence nor entanglement in the whole dynamical process. Surprisingly we find that in both cases the singlet yields are the same, and based on this result, we believe that the dark state population determines the singlet yield completely, and the dark state coherence and entanglement have little contribution to it. Finally, we also find that the dark state population as well as the singlet yield anisotropy is fragile to the vertical magnetic noise. However, the orientation is robust and is even enhanced by the parallel magnetic noise because the dark states expand a decoherence-free subspace. The dark state population as well as the orientation is more robust to the hyperfine coupling noise.

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.

Is it possible to receive information about the historical geomagnetic declination from church orientations?

NASA Astrophysics Data System (ADS)

Draxler, Andrea; Rauch, Roman; Gruber, Karin; Leohardt, Roman

2013-04-01

It is widely known that the main structure of many churches was planned and built in an east-ward direction. This procedure, called "easting", was used for centuries especially in catholic structures. "Easting" usually refers to the direction of sunrise at the church patron's day. Assuming however that this direction is estimated by compasses there could be a significant correlation between the geographic orientation of the churches and the value of magnetic declination at the date of building. In Europe compasses are known since the 11th century. For this study altogether 124 churches located in lower Austria and built between 1100 to 1900 were analysed. Of primary interest is the geographic orientation of the churches, which was extracted out of georeferenced satellite images in Google Earth and the NO Atlas. The measured orientation of the church's nave is then compared to the geographic east direction as well as to the magnetic east direction, according to the magnetic field in the church's construction year which is determined by published geomagnetic field models. The resulting deviations for the geographic east direction split our data into two groups: churches that were built before 1500 and churches that were constructed after 1500. The boundary between these two data sets is marked by the Ottoman wars in the 16th century, where a lot of churches were destroyed. After 1500 the differences between the church's orientation and the geographic east direction are significantly bigger than before the Ottoman wars, so we shifted our focus for the following calculations on the time span from 1100 to 1500, where we found quite small deviations for both the geographic and the magnetic east direction. The principle idea of church orientation, usually referred to as "Easting" is to direct the church to the point of sunrise on the patron saint's day. Therefore we also calculated the solar azimuth on the patron saint's day and compared it to the orientation of the church. The differences we found were bigger than the deviations we got from the comparisons to the geographic and magnetic east directions, so this indicates that practically the solar azimuth was not used for the church's direction. Furthermore, our investigations indicate that the orientation of the investigated churches is more likely to be related to the geographic east direction than to magnetic east.

Magnetite-based Magnetoreception in Animals: 25+ Years of Theory & Experimentation

NASA Astrophysics Data System (ADS)

Kirschvink, J. L.; Walker, M. M.

2005-12-01

Living organisms ranging from bacteria through higher vertebrates rely on orientation, navigation, and homing to survive. Any sensory cue that enhances these behaviors will be subject to intense natural selection over geological time. Reproducible behavioral responses to earth-strength magnetic fields(1) have been documented in Bacteria, Protoctists, and in nearly every major group of animals, and are possibly also present in the Archaea. Several groups of animals, including birds and cetaceans, respond behaviorally to magnetic anomalies below 100 nT in magnitude, implying that their magnetoreception ability approaches the thermal noise limit. This approach to thermal noise is commonly observed in other sensory systems, including hearing, olfaction, and electroreception. The hypothesis of magnetite-based magnetoreception(2) is the only theory proposed so far that is capable of explaining all of the magnetic behavioral data. Tiny crystals of single-domain magnetite (or in some bacteria, greigite) rotate the cells of microorganisms passively like a simple compass needle. The initial detection of biogenic magnetite with rock magnetic techniques in birds and bees over 25 years ago has led progressively to the identification of a group of specialized cells in fish and birds which contain organized magnetite-containing structures. In these animals (and presumably all vertebrates) magnetic signals are transmitted to the brain via the ophthalmic branch of the trigeminal nerve(3, 4). Experiments with pulse-remagnetization, like those that convert North-seeking bacteria into South-seekers, have dramatic effects on animal behavior, confirming the role of magnetite in the sensory system. This is therefore a general mechanism for a highly sensitive magnetic sense, the origin of which probably dates to the ancestral metazoan, and perhaps earlier. The largest debate presently occurring in the field concerns the interpretation of magnetic compass responses that vary with intensity and color of light. Some biologists interpret the tendency of birds and amphibians to orient randomly under red lights, but not under shorter wavelengths, as evidence for the existence of a separate compass receptor involving light. However, even some magnetotactic bacteria change their behavior in red light,(5) and all such effects reported to date in animals can be explained simply as a visual influence on an animal's choice of behavior. Although the light-dependent mechanism might be physically plausible for a compass (but not for a high-resolution magnetic), natural selection cannot develop it without a separation from the visual system (exaptation), for which there is no evidence. 1. R. Wiltschko, W. Wiltschko, Magnetic orientation in animals, Zoophysiology (Springer, Berlin, 1995), pp. 297. 2. J. L. Kirschvink, Ph.D. Thesis, Princeton University (1979). 3. J. L. Kirschvink, M. M. Walker, C. Deibel, Current Opinion in Neurobiology 11, 462 (2001). 4. M. M. Walker, T. E. Dennis, J. L. Kirschvink, Current Opinion in Neurobiology 12, 735 (Dec, 2002). 5. R. B. Frankel, D. A. Bazylinski, M. S. Johnson, B. L. Taylor, Biophysical Journal 73, 994 (1997).

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...

Antennal circadian clocks coordinate sun compass orientation in migratory monarch butterflies.

PubMed

Merlin, Christine; Gegear, Robert J; Reppert, Steven M

2009-09-25

During their fall migration, Eastern North American monarch butterflies (Danaus plexippus) use a time-compensated Sun compass to aid navigation to their overwintering grounds in central Mexico. It has been assumed that the circadian clock that provides time compensation resides in the brain, although this assumption has never been examined directly. Here, we show that the antennae are necessary for proper time-compensated Sun compass orientation in migratory monarch butterflies, that antennal clocks exist in monarchs, and that they likely provide the primary timing mechanism for Sun compass orientation. These unexpected findings pose a novel function for the antennae and open a new line of investigation into clock-compass connections that may extend widely to other insects that use this orientation mechanism.

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…

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...

Lateralized activation of Cluster N in the brains of migratory songbirds

PubMed Central

Liedvogel, Miriam; Feenders, Gesa; Wada, Kazuhiro; Troje, Nikolaus F.; Jarvis, Erich D.; Mouritsen, Henrik

2008-01-01

Cluster N is a cluster of forebrain regions found in night-migratory songbirds that shows high activation of activity-dependent gene expression during night-time vision. We have suggested that Cluster N may function as a specialized night-vision area in night-migratory birds and that it may be involved in processing light-mediated magnetic compass information. Here, we investigated these ideas. We found a significant lateralized dominance of Cluster N activation in the right hemisphere of European robins (Erithacus rubecula). Activation predominantly originated from the contralateral (left) eye. Garden warblers (Sylvia borin) tested under different magnetic field conditions and under monochromatic red light did not show significant differences in Cluster N activation. In the fairly sedentary Sardinian warbler (Sylvia melanocephala), which belongs to the same phyolgenetic clade, Cluster N showed prominent activation levels, similar to that observed in garden warblers and European robins. Thus, it seems that Cluster N activation occurs at night in all species within predominantly migratory groups of birds, probably because such birds have the capability of switching between migratory and sedentary life styles. The activation studies suggest that although Cluster N is lateralized, as is the dependence on magnetic compass orientation, either Cluster N is not involved in magnetic processing or the magnetic modulations of the primary visual signal, forming the basis for the currently supported light-dependent magnetic compass mechanism, are relatively small such that activity-dependent gene expression changes are not sensitive enough to pick them up. PMID:17331212

An fMRI study of caring vs self-focus during induced compassion and pride.

PubMed

Simon-Thomas, Emiliana R; Godzik, Jakub; Castle, Elizabeth; Antonenko, Olga; Ponz, Aurelie; Kogan, Aleksander; Keltner, Dacher J

2012-08-01

This study examined neural activation during the experience of compassion, an emotion that orients people toward vulnerable others and prompts caregiving, and pride, a self-focused emotion that signals individual strength and heightened status. Functional magnetic resonance images (fMRI) were acquired as participants viewed 55 s continuous sequences of slides to induce either compassion or pride, presented in alternation with sequences of neutral slides. Emotion self-report data were collected after each slide condition within the fMRI scanner. Compassion induction was associated with activation in the midbrain periaqueductal gray (PAG), a region that is activated during pain and the perception of others' pain, and that has been implicated in parental nurturance behaviors. Pride induction engaged the posterior medial cortex, a region that has been associated with self-referent processing. Self-reports of compassion experience were correlated with increased activation in a region near the PAG, and in the right inferior frontal gyrus (IFG). Self-reports of pride experience, in contrast, were correlated with reduced activation in the IFG and the anterior insula. These results provide preliminary evidence towards understanding the neural correlates of important interpersonal dimensions of compassion and pride. Caring (compassion) and self-focus (pride) may represent core appraisals that differentiate the response profiles of many emotions.

An fMRI study of caring vs self-focus during induced compassion and pride

PubMed Central

Godzik, Jakub; Castle, Elizabeth; Antonenko, Olga; Ponz, Aurelie; Kogan, Aleksander; Keltner, Dacher J.

2012-01-01

This study examined neural activation during the experience of compassion, an emotion that orients people toward vulnerable others and prompts caregiving, and pride, a self-focused emotion that signals individual strength and heightened status. Functional magnetic resonance images (fMRI) were acquired as participants viewed 55 s continuous sequences of slides to induce either compassion or pride, presented in alternation with sequences of neutral slides. Emotion self-report data were collected after each slide condition within the fMRI scanner. Compassion induction was associated with activation in the midbrain periaqueductal gray (PAG), a region that is activated during pain and the perception of others’ pain, and that has been implicated in parental nurturance behaviors. Pride induction engaged the posterior medial cortex, a region that has been associated with self-referent processing. Self-reports of compassion experience were correlated with increased activation in a region near the PAG, and in the right inferior frontal gyrus (IFG). Self-reports of pride experience, in contrast, were correlated with reduced activation in the IFG and the anterior insula. These results provide preliminary evidence towards understanding the neural correlates of important interpersonal dimensions of compassion and pride. Caring (compassion) and self-focus (pride) may represent core appraisals that differentiate the response profiles of many emotions. PMID:21896494

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…

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.

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.

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.

46 CFR 77.11-1 - When required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 77.11-1 When required. (a) All mechanically propelled vessels in ocean, coastwise or Great Lakes service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

46 CFR 96.17-1 - When required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 96.17-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

46 CFR 77.11-1 - When required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 77.11-1 When required. (a) All mechanically propelled vessels in ocean, coastwise or Great Lakes service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

46 CFR 195.19-1 - When required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 195.19-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

46 CFR 195.19-1 - When required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 195.19-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

46 CFR 96.17-1 - When required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MISCELLANEOUS SYSTEMS AND EQUIPMENT Magnetic Compass and Gyrocompass § 96.17-1 When required. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b) All... gyrocompass in addition to the magnetic compass. (c) Each vessel must have an illuminated repeater for the...

The magnetic orientation of the Antarctic amphipod Gondogeneia antarctica is cancelled by very weak radiofrequency fields.

PubMed

Tomanova, K; Vacha, M

2016-06-01

Studies on weak man-made radiofrequency (RF) electromagnetic fields affecting animal magnetoreception aim for a better understanding of the reception mechanism and also point to a new phenomenon having possible consequences in ecology and environmental protection. RF impacts on magnetic compasses have recently been demonstrated in migratory birds and other vertebrates. We set out to investigate the effect of RF on the magnetic orientation of the Antarctic krill species Gondogeneia antarctica, a small marine crustacean widespread along the Antarctic littoral line. Here, we show that upon release, G. antarctica (held under laboratory conditions) escaped in the magnetically seaward direction along the magnetic sea-land axis (y-axis) of the home beach. However, the animals were disoriented after being exposed to RF. Orientation was lost not only in an RF field with a magnetic flux density of 20 nT, as expected according to the literature, but even under the 2 nT originally intended as a control. Our results extend recent findings of the extraordinary sensitivity of animal magnetoreception to weak RF fields in marine invertebrates. © 2016. Published by The Company of Biologists Ltd.

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.

Orientation with a Viking sun-compass, a shadow-stick, and two calcite sunstones under various weather conditions.

PubMed

Bernáth, Balázs; Blahó, Miklós; Egri, Adám; Barta, András; Kriska, György; Horváth, Gábor

2013-09-01

It is widely accepted that Vikings used sun-compasses to derive true directions from the cast shadow of a gnomon. It has been hypothesized that when a cast shadow was not formed, Viking navigators relied on crude skylight polarimetry with the aid of dichroic or birefringent crystals, called "sunstones." We demonstrate here that a simple tool, that we call "shadow-stick," could have allowed orientation by a sun-compass with satisfying accuracy when shadows were not formed, but the sun position could have reliably been estimated. In field tests, we performed orientation trials with a set composed of a sun-compass, two calcite sunstones, and a shadow-stick. We show here that such a set could have been an effective orientation tool for Vikings only when clear, blue patches of the sky were visible.

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.

Map and Compass Skills for the Secondary School (Understanding Topographic Maps, Developing Compass Skills, and Orienteering). Instructional Activities Series IA/S-18.

ERIC Educational Resources Information Center

Larkin, Robert P.

This activity is one of a series of 17 teacher-developed instructional activities for geography at the secondary-grade level described in SO 009 140. The activity investigates the development of compass skills, map skills, and orienteering. It employs the educational-games approach. Given specific exercises and instructions, students become…

Orienteering: The Race With a Compass

ERIC Educational Resources Information Center

Boyd, Ellsworth

1978-01-01

Orienteering, a Scandinavian sport that has recently become popular in the United States, combines outdoor adventure, practical skills, physical fitness and fun. Here it is used to help young students develop survival skills using a compass. (Author/RK)

Remotely readable fiber optic compass

DOEpatents

Migliori, Albert; Swift, Gregory W.; Garrett, Steven L.

1986-01-01

A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optical axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

Remotely readable fiber optic compass

DOEpatents

Migliori, A.; Swift, G.W.; Garrett, S.L.

1985-04-30

A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optical axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

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.

Paleomagnetic results of Neogene strata in Eastern Vietnam and their paleogeographic Implications

NASA Astrophysics Data System (ADS)

Weiwei, C.; Zhao, X.; Liu, Z.; Dong Pha, P.

2017-12-01

Neogene paleomagnetic data from the Vietnam, southeastern margin of the Indochina Block, are essential to reconstruct post-collisional paleogeography. This is key to understanding the evolution of the western South China Sea and verifying the model of extrusion tectonic. Mid-Miocene siltstone of the Song Ba Formation and Pliocene basalt were sampled from Phu Tue area, eastern Vietnam. Paleomagnetic samples were collected using a gasoline-powered drill and a magnetic compass mounted on an orienting device. We corrected for the effect of local magnetic anomalies on magnetic orientation by taking solar azimuths using a sun compass. For most samples, the discrepancy between the two compass readings is within 3°. Remanent magnetization measurements were carried out with 2G-755-4K cryogenic magnetometers, installed in the Plaleomagnetism Laboratory, Tongji University, Shanghai. All the instruments are located in a shielded room with residual fields less than 200 nT. The anisotropy of magnetic susceptibility (AMS) results of four siltstone sites (sites 2, 6, 9, 10) indicate the siltstone preserve a normal sedimentary magnetic fabric. The other sites of the AMS (including basalt sites) show that the directions of K1, K2, K3 are scattered without any regulation. The thermal demagnetization and AF demagnetization were performed on specimens and stepwise demagnetization up to 600°C or 150 mT. ChRM directions were determined for all the specimens using principal component analysis. The directions obtained from Neogene rocks are far from the present geomagnetic field (PGF) and include antipodal dual polarities, suggesting a primary origin. A visible fluctuation in paleomagnetic direction from one site to another is evident from the results. Shallow inclination are obtained from most samples which range of 7.4° to 21.5°. The siltstone declination range of 16.8° to 34.5° while the basalt declination rang of 178.3° to 335.0°. This wide range of direction fluctuation suggests a long record of secular variation and has been sufficiently averaged out by formation mean calculations. The preliminary data suggest that that southern Indochina Block was at a mean paleolatitude of 5° 10° N during the Paleogene. The relative rotation should be caused by the local deformation and the motion of the entire lithospheric block.

Buffering Impostor Feelings with Kindness: The Mediating Role of Self-compassion between Gender-Role Orientation and the Impostor Phenomenon

PubMed Central

Patzak, Alexandra; Kollmayer, Marlene; Schober, Barbara

2017-01-01

The impostor phenomenon (IP) refers to high-achievers who underestimate their abilities and thus fear being unmasked as impostors. IP sufferers attribute their success to factors other than their abilities, entailing negative emotions, unfavorable motivations, and reduced well-being. The IP was originally conceptualized as a predominantly female experience, and is thus seen as an important psychological barrier for female academic careers. Empirical findings of gender differences in the IP are equivocal, but sparse research on associations between gender-role orientation and the IP indicates that feminine students suffer more intensely from the IP than masculine students. Femininity and masculinity are also related to self-compassion, a rather young construct that enhances emotional resilience, well-being, and academic achievement. Self-compassion involves being kind to oneself when failing, perceiving one’s inadequacies as part of the human condition, and being mindful about negative aspects of oneself. It reduces fear of failure, denial of competences, and self-doubts which are central components of the IP. However, relations between self-compassion and the IP have not been investigated to date. In this study, we examine self-compassion as a potential resilience factor against the IP, taking gender and gender-role orientation into account. In a cross-sectional online survey, we investigated 459 (315 female) high-achieving first-year undergraduate students. Results include: Female, feminine, and undifferentiated students score higher on measures of the IP and lower on measures of self-compassion than male, masculine, or androgynous students. Higher levels of the IP are associated with lower levels of self-compassion across all students tested. Self-compassion further mediates the relationship between gender-role orientation and the IP. Interventions to enhance self-compassion might thus be an effective way to overcome impostor feelings. Female, feminine, and undifferentiated students might benefit most from facilitation of self-compassion in education. PMID:28798714

Are migrating raptors guided by a geomagnetic compass?

USGS Publications Warehouse

Thorup, Kasper; Fuller, Mark R.; Alerstam, T.; Hake, M.; Kjellen, N.; Standberg, R.

2006-01-01

We tested whether routes of raptors migrating over areas with homogeneous topography follow constant geomagnetic courses more or less closely than constant geographical courses. We analysed the routes taken over land of 45 individual raptors tracked by satellite-based radiotelemetry: 25 peregrine falcons, Falco peregrinus, on autumn migration between North and South America, and seven honey buzzards, Pernis apivorus, and 13 ospreys, Pandion haliaetus, on autumn migration between Europe and Africa. Overall, migration directions showed a better agreement with constant geographical than constant geomagnetic courses. Tracks deviated significantly from constant geomagnetic courses, but were not significantly different from geographical courses. After we removed movements directed far from the mean direction, which may not be migratory movements, migration directions still showed a better agreement with constant geographical than constant geomagnetic courses, but the directions of honey buzzards and ospreys were not significantly different from constant geomagnetic courses either. That migration routes of raptors followed by satellite telemetry are in closer accordance with constant geographical compass courses than with constant geomagnetic compass courses may indicate that geographical (e.g. based on celestial cues) rather than magnetic compass mechanisms are of dominating importance for the birds' long-distance orientation.

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,…

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…

Ontogenetic development of magnetic compass orientation in domestic chickens (Gallus gallus).

PubMed

Denzau, Susanne; Nießner, Christine; Rogers, Lesley J; Wiltschko, Wolfgang

2013-08-15

Domestic chickens (Gallus gallus) can be trained to search for a social stimulus in a specific magnetic direction, and cryptochrome 1a, found in the retina, has been proposed as a receptor molecule mediating magnetic directions. The present study combines immuno-histochemical and behavioural data to analyse the ontogenetic development of this ability. Newly hatched chicks already have a small amount of cryptochrome 1a in their violet cones; on day 5, the amount of cryptochrome 1a reached the same level as in adult chickens, suggesting that the physical basis for magnetoreception is present. In behavioural tests, however, young chicks 5 to 7 days old failed to show a preference of the training direction; on days 8, 9 and 12, they could be successfully trained to search along a specific magnetic axis. Trained and tested again 1 week later, the chicks that had not shown a directional preference on days 5 to 7 continued to search randomly, while the chicks tested from day 8 onward preferred the correct magnetic axis when tested 1 week later. The observation that the magnetic compass is not functional before day 8 suggests that certain maturation processes in the magnetosensitive system in the brain are not yet complete before that day. The reasons why chicks that have been trained before that day fail to learn the task later remain unclear.

Using an electronic compass to determine telemetry azimuths

USGS Publications Warehouse

Cox, R.R.; Scalf, J.D.; Jamison, B.E.; Lutz, R.S.

2002-01-01

Researchers typically collect azimuths from known locations to estimate locations of radiomarked animals. Mobile, vehicle-mounted telemetry receiving systems frequently are used to gather azimuth data. Use of mobile systems typically involves estimating the vehicle's orientation to grid north (vehicle azimuth), recording an azimuth to the transmitter relative to the vehicle azimuth from a fixed rosette around the antenna mast (relative azimuth), and subsequently calculating an azimuth to the transmitter (animal azimuth). We incorporated electronic compasses into standard null-peak antenna systems by mounting the compass sensors atop the antenna masts and evaluated the precision of this configuration. This system increased efficiency by eliminating vehicle orientation and calculations to determine animal azimuths and produced estimates of precision (azimuth SD=2.6 deg., SE=0.16 deg.) similar to systems that required orienting the mobile system to grid north. Using an electronic compass increased efficiency without sacrificing precision and should produce more accurate estimates of locations when marked animals are moving or when vehicle orientation is problematic.

Magnetoreception and its trigeminal mediation in the homing pigeon

NASA Astrophysics Data System (ADS)

Mora, Cordula V.; Davison, Michael; Martin Wild, J.; Walker, Michael M.

2004-11-01

Two conflicting hypotheses compete to explain how a homing pigeon can return to its loft over great distances. One proposes the use of atmospheric odours and the other the Earth's magnetic field in the `map' step of the `map and compass' hypothesis of pigeon homing. Although magnetic effects on pigeon orientation provide indirect evidence for a magnetic `map', numerous conditioning experiments have failed to demonstrate reproducible responses to magnetic fields by pigeons. This has led to suggestions that homing pigeons and other birds have no useful sensitivity to the Earth's magnetic field. Here we demonstrate that homing pigeons (Columba livia) can discriminate between the presence and absence of a magnetic anomaly in a conditioned choice experiment. This discrimination is impaired by attachment of a magnet to the cere, local anaesthesia of the upper beak area, and bilateral section of the ophthalmic branch of the trigeminal nerve, but not of the olfactory nerve. These results suggest that magnetoreception (probably magnetite-based) occurs in the upper beak area of the pigeon. Traditional methods of rendering pigeons anosmic might therefore cause simultaneous impairment of magnetoreception so that future orientation experiments will require independent evaluation of the pigeon's magnetic and olfactory systems.

Magnetoreception and its trigeminal mediation in the homing pigeon.

PubMed

Mora, Cordula V; Davison, Michael; Wild, J Martin; Walker, Michael M

2004-11-25

Two conflicting hypotheses compete to explain how a homing pigeon can return to its loft over great distances. One proposes the use of atmospheric odours and the other the Earth's magnetic field in the 'map' step of the 'map and compass' hypothesis of pigeon homing. Although magnetic effects on pigeon orientation provide indirect evidence for a magnetic 'map', numerous conditioning experiments have failed to demonstrate reproducible responses to magnetic fields by pigeons. This has led to suggestions that homing pigeons and other birds have no useful sensitivity to the Earth's magnetic field. Here we demonstrate that homing pigeons (Columba livia) can discriminate between the presence and absence of a magnetic anomaly in a conditioned choice experiment. This discrimination is impaired by attachment of a magnet to the cere, local anaesthesia of the upper beak area, and bilateral section of the ophthalmic branch of the trigeminal nerve, but not of the olfactory nerve. These results suggest that magnetoreception (probably magnetite-based) occurs in the upper beak area of the pigeon. Traditional methods of rendering pigeons anosmic might therefore cause simultaneous impairment of magnetoreception so that future orientation experiments will require independent evaluation of the pigeon's magnetic and olfactory systems.

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.

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.

Cryptochrome Mediates Light-Dependent Magnetosensitivity of Drosophila's Circadian Clock

PubMed Central

Yoshii, Taishi; Ahmad, Margaret; Helfrich-Förster, Charlotte

2009-01-01

Since 1960, magnetic fields have been discussed as Zeitgebers for circadian clocks, but the mechanism by which clocks perceive and process magnetic information has remained unknown. Recently, the radical-pair model involving light-activated photoreceptors as magnetic field sensors has gained considerable support, and the blue-light photoreceptor cryptochrome (CRY) has been proposed as a suitable molecule to mediate such magnetosensitivity. Since CRY is expressed in the circadian clock neurons and acts as a critical photoreceptor of Drosophila's clock, we aimed to test the role of CRY in magnetosensitivity of the circadian clock. In response to light, CRY causes slowing of the clock, ultimately leading to arrhythmic behavior. We expected that in the presence of applied magnetic fields, the impact of CRY on clock rhythmicity should be altered. Furthermore, according to the radical-pair hypothesis this response should be dependent on wavelength and on the field strength applied. We tested the effect of applied static magnetic fields on the circadian clock and found that flies exposed to these fields indeed showed enhanced slowing of clock rhythms. This effect was maximal at 300 μT, and reduced at both higher and lower field strengths. Clock response to magnetic fields was present in blue light, but absent under red-light illumination, which does not activate CRY. Furthermore, cryb and cryOUT mutants did not show any response, and flies overexpressing CRY in the clock neurons exhibited an enhanced response to the field. We conclude that Drosophila's circadian clock is sensitive to magnetic fields and that this sensitivity depends on light activation of CRY and on the applied field strength, consistent with the radical pair mechanism. CRY is widespread throughout biological systems and has been suggested as receptor for magnetic compass orientation in migratory birds. The present data establish the circadian clock of Drosophila as a model system for CRY-dependent magnetic sensitivity. Furthermore, given that CRY occurs in multiple tissues of Drosophila, including those potentially implicated in fly orientation, future studies may yield insights that could be applicable to the magnetic compass of migratory birds and even to potential magnetic field effects in humans. PMID:19355790

Exploring Magnetic Fields with a Compass

NASA Astrophysics Data System (ADS)

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 paper, we present a series of simple activities adapted from the Matter & Interactions textbook for doing just this. Interestingly, these simple measurements are comparable to predictions made by the Bohr model of the atom. Although antiquated, Bohr's atom can lead the way to a deeper analysis of the atomic properties of magnets. Although originally developed for an introductory calculus-based course, these activities can easily be adapted for use in an algebra-based class or even at the high school level.

Magnetoreception in birds: different physical processes for two types of directional responses

PubMed Central

Wiltschko, Roswitha; Stapput, Katrin; Ritz, Thorsten; Thalau, Peter; Wiltschko, Wolfgang

2007-01-01

Migratory orientation in birds involves an inclination compass based on radical-pair processes. Under certain light regimes, however, “fixed-direction” responses are observed that do not undergo the seasonal change between spring and autumn typical for migratory orientation. To identify the underlying transduction mechanisms, we analyzed a fixed-direction response under a combination of 502 nm turquoise and 590 nm yellow light, with migratory orientation under 565 nm green light serving as the control. High-frequency fields, diagnostic for a radical-pair mechanism, disrupted migratory orientation without affecting fixed-direction responses. Local anaesthesia of the upper beak where magnetite is found in birds, in contrast, disrupted the fixed-direction response without affecting migratory orientation. The two types of responses are thus based on different physical principles, with the compass response based on a radical pair mechanism and the fixed-direction responses probably originating in magnetite-based receptors in the upper beak. Directional input from these receptors seems to affect the behavior only when the regular inclination compass does not work properly. Evolutionary considerations suggest that magnetite-based receptors may represent an ancient mechanism that, in birds, has been replaced by the modern inclination compass based on radical-pair processes now used for directional orientation. PMID:19404459

Investigating Factors that Generate and Maintain Variation in Migratory Orientation: A Primer for Recent and Future Work.

PubMed

Delmore, Kira E; Liedvogel, Miriam

2016-01-01

The amazing accuracy of migratory orientation performance across the animal kingdom is facilitated by the use of magnetic and celestial compass systems that provide individuals with both directional and positional information. Quantitative genetics analyses in several animal systems suggests that migratory orientation has a strong genetic component. Nevertheless, the exact identity of genes controlling orientation remains largely unknown, making it difficult to obtain an accurate understanding of this fascinating behavior on the molecular level. Here, we provide an overview of molecular genetic techniques employed thus far, highlight the pros and cons of various approaches, generalize results from species-specific studies whenever possible, and evaluate how far the field has come since early quantitative genetics studies. We emphasize the importance of examining different levels of molecular control, and outline how future studies can take advantage of high-resolution tracking and sequencing techniques to characterize the genomic architecture of migratory orientation.

Value Orientation of Singapore Adolescents Towards Truthfulness, Justice and Compassion.

ERIC Educational Resources Information Center

Seng, SeokHoon; Siang, Low Meow; Wei, Tan Tai

This study examined the value orientation of Singapore adolescents toward the three fundamental values of truthfulness, justice, and compassion. A random sample of 315 secondary school students from 4 schools in Singapore (135 males and 180 females) completed a questionnaire, and a select sample of 19 students completed interviews about their…

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...

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

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...

Configuration of the magnetosome chain: a natural magnetic nanoarchitecture.

PubMed

Orue, I; Marcano, L; Bender, P; García-Prieto, A; Valencia, S; Mawass, M A; Gil-Cartón, D; Alba Venero, D; Honecker, D; García-Arribas, A; Fernández Barquín, L; Muela, A; Fdez-Gubieda, M L

2018-04-26

Magnetospirillum gryphiswaldense is a microorganism with the ability to biomineralize magnetite nanoparticles, called magnetosomes, and arrange them into a chain that behaves like a magnetic compass. Rather than straight lines, magnetosome chains are slightly bent, as evidenced by electron cryotomography. Our experimental and theoretical results suggest that due to the competition between the magnetocrystalline and shape anisotropies, the effective magnetic moment of individual magnetosomes is tilted out of the [111] crystallographic easy axis of magnetite. This tilt does not affect the direction of the chain net magnetic moment, which remains along the [111] axis, but explains the arrangement of magnetosomes in helical-like shaped chains. Indeed, we demonstrate that the chain shape can be reproduced by considering an interplay between the magnetic dipolar interactions between magnetosomes, ruled by the orientation of the magnetosome magnetic moment, and a lipid/protein-based mechanism, modeled as an elastic recovery force exerted on the magnetosomes.

Orienteering Map and Compass: A Guide and Outline to Its Science and Practice.

ERIC Educational Resources Information Center

Campbell, Mel; Burton, VirLynn

This orienteering manual is used to teach map and compass skills to elementary school students on an overnight outdoor experience administered by volunteers. Although the experience is aimed at elementary students, student teachers have the opportunity to participate as instructors. After a few words to the volunteers on maximizing learning among…

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.

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.

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...

Current profilers and current meters: compass and tilt sensors errors and calibration

NASA Astrophysics Data System (ADS)

Le Menn, M.; Lusven, A.; Bongiovanni, E.; Le Dû, P.; Rouxel, D.; Lucas, S.; Pacaud, L.

2014-08-01

Current profilers and current meters have a magnetic compass and tilt sensors for relating measurements to a terrestrial reference frame. As compasses are sensitive to their magnetic environment, they must be calibrated in the configuration in which they will be used. A calibration platform for magnetic compasses and tilt sensors was built, based on a method developed in 2007, to correct angular errors and guarantee a measurement uncertainty for instruments mounted in mooring cages. As mooring cages can weigh up to 800 kg, it was necessary to find a suitable place to set up this platform, map the magnetic fields in this area and dimension the platform to withstand these loads. It was calibrated using a GPS positioning technique. The platform has a table that can be tilted to calibrate the tilt sensors. The measurement uncertainty of the system was evaluated. Sinusoidal corrections based on the anomalies created by soft and hard magnetic materials were tested, as well as manufacturers’ calibration methods.

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…

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.

Orientation in birds. The sun compass.

PubMed

Schmidt-Koenig, K; Ganzhorn, J U; Ranvaud, R

1991-01-01

The sun compass was discovered by G. Kramer in caged birds showing migratory restlessness. Subsequent experiments with caged birds employing directional training and clock shifts, carried out by Hoffman and Schmidt-Koenig, showed that the sun azimuth is used, and the sun altitude ignored. In the laboratory, McDonald found the accuracy to be +/- 3 degrees(-)+/- 5 degrees. According to Hoffmann and Schmidt-Koenig, caged birds trained at medium northern latitudes were able to allow for the sun's apparent movement north of the arctic circle, but not in equatorial and trans-equatorial latitudes. In homing experiments, and employing clock shifts, Schmidt-Koenig demonstrated that the sun compass is used by homing pigeons during initial orientation. This finding is the principal evidence for the existence of a map-and-compass navigational system. Pigeons living in equatorial latitudes utilize the sun compass even under the extreme solar conditions of equinox, achieving angular resolution of about 3 degrees in homing experiments. According to preliminary analyses, the homing pigeons' ephemerides are retarded by several weeks (Ranvaud, Schmidt-Koenig, Ganzhorn et al.).

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.

Do migratory flight paths of raptors follow constant geographical or geomagnetic courses?

USGS Publications Warehouse

Thorup, K.; Fuller, M.; Alerstam, T.; Hake, M.; Kjellen, N.; Strandberg, R.

2006-01-01

We tested whether routes of raptors migrating over areas with homogeneous topography follow constant geomagnetic courses more or less closely than constant geographical courses. We analysed the routes taken over land of 45 individual raptors tracked by satellite-based radiotelemetry: 25 peregrine falcons, Falco peregrinus, on autumn migration between North and South America, and seven honey buzzards, Pernis apivorus, and 13 ospreys, Pandion haliaetus, on autumn migration between Europe and Africa. Overall, migration directions showed a better agreement with constant geographical than constant geomagnetic courses. Tracks deviated significantly from constant geomagnetic courses, but were not significantly different from geographical courses. After we removed movements directed far from the mean direction, which may not be migratory movements, migration directions still showed a better agreement with constant geographical than constant geomagnetic courses, but the directions of honey buzzards and ospreys were not significantly different from constant geomagnetic courses either. That migration routes of raptors followed by satellite telemetry are in closer accordance with constant geographical compass courses than with constant geomagnetic compass courses may indicate that geographical (e.g. based on celestial cues) rather than magnetic compass mechanisms are of dominating importance for the birds' long-distance orientation.

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.

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.

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.

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.

46 CFR 169.709 - Compass.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic steering...

46 CFR 169.709 - Compass.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic steering...

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

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.

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.

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

Modeling Compassion in Critical, Justice-Oriented Teacher Education

ERIC Educational Resources Information Center

Conklin, Hilary Gehlbach

2008-01-01

As the work of teacher education becomes increasingly focused on the challenges of helping mostly white, monolingual, middle-class prospective teachers become compassionate, successful teachers of racially, culturally, linguistically, economically, and academically diverse students, some teacher educators struggle to find compassion for the…

Autonomous Underwater Munitions and Explosives of Concern Detection System

DTIC Science & Technology

2015-03-01

Field Magnetometer ......................................................................... 19 5.3.2 Fluxgate Compass...through the vehicle control system. Magnetic measurements are sampled at 10 Hz. 5.3.2 Fluxgate Compass Located in the magnetometer module pressure...pitch, and roll) from the fluxgate compass and the total field magnetometer measurements are required for processing into the MagComp compensation

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.

Discordant timing between antennae disrupts sun compass orientation in migratory monarch butterflies

PubMed Central

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

2014-01-01

To navigate during their long-distance migration, monarch butterflies (Danaus plexippus) use a time-compensated sun compass. The sun compass timing elements reside in light-entrained circadian clocks in the antennae. Here we show that either antenna is sufficient for proper time compensation. However, migrants with either antenna painted black (to block light entrainment) and the other painted clear (to permit light entrainment) display disoriented group flight. Remarkably, when the black-painted antenna is removed, re-flown migrants with a single, clear-painted antenna exhibit proper orientation behaviour. Molecular correlates of clock function reveal that period and timeless expression is highly rhythmic in brains and clear-painted antennae, while rhythmic clock gene expression is disrupted in black-painted antennae. Our work shows that clock outputs from each antenna are processed and integrated together in the monarch time-compensated sun compass circuit. This dual timing system is a novel example of the regulation of a brain-driven behaviour by paired organs. PMID:22805565

Role of atomic spin-mechanical coupling in the problem of a magnetic biocompass

NASA Astrophysics Data System (ADS)

Cao, Yunshan; Yan, Peng

2018-04-01

It is a well established notion that animals can detect the Earth's magnetic field, while the biophysical origin of such magnetoreception is still elusive. Recently, a magnetic receptor Drosophila CG8198 (MagR) with a rodlike protein complex is reported [S. Qin et al., Nat. Mater. 15, 217 (2016), 10.1038/nmat4484] to act like a compass needle to guide the magnetic orientation of animals. This view, however, is challenged [M. Meister, Elife 5, e17210 (2016), 10.7554/eLife.17210] by arguing that thermal fluctuations beat the Zeeman coupling of the proteins's magnetic moment with the rather weak geomagnetic field (˜25 -65 μ T ). In this work, we show that the spin-mechanical interaction at the atomic scale gives rise to a high blocking temperature which allows a good alignment of the protein's magnetic moment with the Earth's magnetic field at room temperature. Our results provide a promising route to resolve the debate on the thermal behaviors of MagR, and may stimulate a broad interest in spin-mechanical couplings down to atomistic levels.

Historical records of the geomagnetic field

NASA Astrophysics Data System (ADS)

Arneitz, Patrick; Heilig, Balázs; Vadasz, Gergely; Valach, Fridrich; Dolinský, Peter; Hejda, Pavel; Fabian, Karl; Hammerl, Christa; Leonhardt, Roman

2014-05-01

Records of historical direct measurements of the geomagnetic field are invaluable sources to reconstruct temporal variations of the Earth's magnetic field. They provide information about the field evolution back to the late Middle Age. We have investigated such records with focus on Austria and some neighbouring countries. A variety of new sources and source types are examined. These include 19th century land survey and observatory records of the Imperial and Royal "Centralanstalt f. Meteorologie und Erdmagnetismus", which are not included in the existing compilations. Daily measurements at the Imperial and Royal Observatory in Prague have been digitized. The Imperial and Royal Navy carried out observations in the Adriatic Sea during several surveys. Declination values have been collected from famous mining areas in the former Austro-Hungarian Empire. In this connection, a time series for Banska Stiavnica has been compiled. In the meteorological yearbooks of the monastery Kremsmünster regular declination measurements for the first half of the 19th century were registered. Marsigli's observations during military mapping works in 1696 are also included in our collection. Moreover, compass roses on historical maps or declination values marked on compasses, sundials or globes also provide information about ancient field declination. An evaluation of church orientations in Lower Austria and Northern Germany did not support the hypothesis that church naves had been aligned along the East-West direction by means of magnetic compasses. Therefore, this potential source of information must be excluded from our collection. The gathered records are integrated into a database together with corresponding metadata, such as the used measurement instruments and methods. This information allows an assessment of quality and reliability of the historical observations. The combination of compilations of historical measurements with high quality archeo- and paleomagnetic data in a single database enables a reliable joint evaluation of all types of magnetic field records from different origins. This collection forms the basis for a combined inverse modelling of the geomagnetic field evolution.

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

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)

Changing and shielded magnetic fields suppress c-Fos expression in the navigation circuit: input from the magnetosensory system contributes to the internal representation of space in a subterranean rodent

PubMed Central

Burger, Tomáš; Lucová, Marcela; Moritz, Regina E.; Oelschläger, Helmut H. A.; Druga, Rastislav; Burda, Hynek; Wiltschko, Wolfgang; Wiltschko, Roswitha; Němec, Pavel

2010-01-01

The neural substrate subserving magnetoreception and magnetic orientation in mammals is largely unknown. Previous experiments have demonstrated that the processing of magnetic sensory information takes place in the superior colliculus. Here, the effects of magnetic field conditions on neuronal activity in the rodent navigation circuit were assessed by quantifying c-Fos expression. Ansell's mole-rats (Fukomys anselli), a mammalian model to study the mechanisms of magnetic compass orientation, were subjected to natural, periodically changing, and shielded magnetic fields while exploring an unfamiliar circular arena. In the undisturbed local geomagnetic field, the exploration of the novel environment and/or nesting behaviour induced c-Fos expression throughout the head direction system and the entorhinal–hippocampal spatial representation system. This induction was significantly suppressed by exposure to periodically changing and/or shielded magnetic fields; discrete decreases in c-Fos were seen in the dorsal tegmental nucleus, the anterodorsal and the laterodorsal thalamic nuclei, the postsubiculum, the retrosplenial and entorhinal cortices, and the hippocampus. Moreover, in inactive animals, magnetic field intensity manipulation suppressed c-Fos expression in the CA1 and CA3 fields of the hippocampus and the dorsal subiculum, but induced expression in the polymorph layer of the dentate gyrus. These findings suggest that key constituents of the rodent navigation circuit contain populations of neurons responsive to magnetic stimuli. Thus, magnetic information may be integrated with multimodal sensory and motor information into a common spatial representation of allocentric space within this circuit. PMID:20219838

Changing and shielded magnetic fields suppress c-Fos expression in the navigation circuit: input from the magnetosensory system contributes to the internal representation of space in a subterranean rodent.

PubMed

Burger, Tomás; Lucová, Marcela; Moritz, Regina E; Oelschläger, Helmut H A; Druga, Rastislav; Burda, Hynek; Wiltschko, Wolfgang; Wiltschko, Roswitha; Nemec, Pavel

2010-09-06

The neural substrate subserving magnetoreception and magnetic orientation in mammals is largely unknown. Previous experiments have demonstrated that the processing of magnetic sensory information takes place in the superior colliculus. Here, the effects of magnetic field conditions on neuronal activity in the rodent navigation circuit were assessed by quantifying c-Fos expression. Ansell's mole-rats (Fukomys anselli), a mammalian model to study the mechanisms of magnetic compass orientation, were subjected to natural, periodically changing, and shielded magnetic fields while exploring an unfamiliar circular arena. In the undisturbed local geomagnetic field, the exploration of the novel environment and/or nesting behaviour induced c-Fos expression throughout the head direction system and the entorhinal-hippocampal spatial representation system. This induction was significantly suppressed by exposure to periodically changing and/or shielded magnetic fields; discrete decreases in c-Fos were seen in the dorsal tegmental nucleus, the anterodorsal and the laterodorsal thalamic nuclei, the postsubiculum, the retrosplenial and entorhinal cortices, and the hippocampus. Moreover, in inactive animals, magnetic field intensity manipulation suppressed c-Fos expression in the CA1 and CA3 fields of the hippocampus and the dorsal subiculum, but induced expression in the polymorph layer of the dentate gyrus. These findings suggest that key constituents of the rodent navigation circuit contain populations of neurons responsive to magnetic stimuli. Thus, magnetic information may be integrated with multimodal sensory and motor information into a common spatial representation of allocentric space within this circuit.

Interpreting the Effects of Pulse Remagnetization on Animal Behavior

NASA Astrophysics Data System (ADS)

Kirschvink, J. L.; Wang, C. X.; Golash, H. N.; Hilburn, I. A.; Wu, D. A.; Crucilla, S. J.; Badal, Y. D.; Shimojo, S.

2017-12-01

Observations of geomagnetic sensitivity by migratory and homing animals have puzzled biophysicists for over 70 years. Widely dismissed as biophysically implausible due to the lack of physiological ferromagnetic materials [e.g., D.R. Griffin, 1944, 1952], clear and reproducible responses to earth-strength magnetic fields is now firmly established in organisms ranging from Bacteria, Protists, and Animals from numerous phyla, including mollusks, arthropods, and the chordates. Behavior demands sensory transduction, as external stimuli only `get into the nervous system' through sensory cells specialized to transduce the physical stimulus into a modulated stream of action potentials in neurons. Three basic biophysical mechanisms could plausibly explain the biophysical transduction of geomagnetic cues, including electrical induction, hyperfine magnetic field effects on photo-activated free radicals (the `Quantum Compass'), or receptor cells containing biologically-precipitated crystals of a ferromagnetic mineral like magnetite (Fe3O4). The definitive test of a ferromagnetic receptor is the pulse-remagnetization experiment, in which you apply a brief, unidirectional magnetic pulse of about 1 mS in duration, configured to exceed the coercive force of the SD particles and reverse the orientation of the magnetic moment wrt to the crystal axis (typically, a pulse few tens of mT is adequate). A pulse configured in this fashion can be well below the dB/dt level needed to fire a sensory nerve through the induced electric fields. The pulse produces a permanent flip in magnetization direction, the same way information is coded on magnetic tape. Magnetotactic bacteria, exposed to such a pulse, reverse their magnetic swimming directions passively. There are now over 16 peer-reviewed papers in which this experiment has been applied to animals, including birds, all of which show clear and long-lasting effects of the pulse. Such a pulse would have no lasting effect on a quantum compass. Initial experiments with a magnetic pulse of 70 mT on a large primate show a clear effect, although the results are … complex!

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

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

Tenebrio beetles use magnetic inclination compass

NASA Astrophysics Data System (ADS)

Vácha, Martin; Drštková, Dana; Půžová, Tereza

2008-08-01

Animals that guide directions of their locomotion or their migration routes by the lines of the geomagnetic field use either polarity or inclination compasses to determine the field polarity (the north or south direction). Distinguishing the two compass types is a guideline for estimation of the molecular principle of reception and has been achieved for a number of animal groups, with the exception of insects. A standard diagnostic method to distinguish a compass type is based on reversing the vertical component of the geomagnetic field, which leads to the opposite reactions of animals with two different compass types. In the present study, adults of the mealworm beetle Tenebrio molitor were tested by means of a two-step laboratory test of magnetoreception. Beetles that were initially trained to memorize the magnetic position of the light source preferred, during the subsequent test, this same direction, pursuant geomagnetic cues only. In the following step, the vertical component was reversed between the training and the test. The beetles significantly turned their preferred direction by 180°. Our results brought until then unknown original findings that insects, represented here by the T. molitor species, use—in contrast to another previously researched Arthropod, spiny lobster—the inclination compass.

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

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.

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.

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).

Class and compassion: socioeconomic factors predict responses to suffering.

PubMed

Stellar, Jennifer E; Manzo, Vida M; Kraus, Michael W; Keltner, Dacher

2012-06-01

Previous research indicates that lower-class individuals experience elevated negative emotions as compared with their upper-class counterparts. We examine how the environments of lower-class individuals can also promote greater compassionate responding-that is, concern for the suffering or well-being of others. In the present research, we investigate class-based differences in dispositional compassion and its activation in situations wherein others are suffering. Across studies, relative to their upper-class counterparts, lower-class individuals reported elevated dispositional compassion (Study 1), as well as greater self-reported compassion during a compassion-inducing video (Study 2) and for another person during a social interaction (Study 3). Lower-class individuals also exhibited heart rate deceleration-a physiological response associated with orienting to the social environment and engaging with others-during the compassion-inducing video (Study 2). We discuss a potential mechanism of class-based influences on compassion, whereby lower-class individuals' are more attuned to others' distress, relative to their upper-class counterparts.

Light-dependent magnetoreception in birds: the crucial step occurs in the dark.

PubMed

Wiltschko, Roswitha; Ahmad, Margaret; Nießner, Christine; Gehring, Dennis; Wiltschko, Wolfgang

2016-05-01

The Radical Pair Model proposes that the avian magnetic compass is based on spin-chemical processes: since the ratio between the two spin states singlet and triplet of radical pairs depends on their alignment in the magnetic field, it can provide information on magnetic directions. Cryptochromes, blue light-absorbing flavoproteins, with flavin adenine dinucleotide as chromophore, are suggested as molecules forming the radical pairs underlying magnetoreception. When activated by light, cryptochromes undergo a redox cycle, in the course of which radical pairs are generated during photo-reduction as well as during light-independent re-oxidation. This raised the question as to which radical pair is crucial for mediating magnetic directions. Here, we present the results from behavioural experiments with intermittent light and magnetic field pulses that clearly show that magnetoreception is possible in the dark interval, pointing to the radical pair formed during flavin re-oxidation. This differs from the mechanism considered for cryptochrome signalling the presence of light and rules out most current models of an avian magnetic compass based on the radical pair generated during photo-reduction. Using the radical pair formed during re-oxidation may represent a specific adaptation of the avian magnetic compass. © 2016 The Authors.

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)

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

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

Historical Experiments in Students' Hands: Unfragmenting Science through Action and History

NASA Astrophysics Data System (ADS)

Cavicchi, Elizabeth Mary

2008-08-01

Two students, meeting together with a teacher, redid historical experiments. Unlike conventional instruction where science topics and practices often fragment, they experienced interrelatedness among phenomena, participants’ actions, and history. This study narrates actions that fostered an interrelated view. One action involved opening up historical telephones to examine interior circuitry. Another made sound visible in a transparent air column filled with Styrofoam bits and through Lissajous figures produced by reflecting light off orthogonal nineteenth century tuning forks crafted by Koenig and Kohl. Another involved orienting magnetic compasses to reveal the magnetism of conducting wires, historically investigated by Oersted and Schweigger. Replicating Homberg’s triboluminescent compound elicited students’ reflective awareness of history. These actions bore pedagogical value in recovering some of the interrelatedness inherent in the history and reintroducing the wonder of science phenomena to students today.

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.

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 sun compass revisited

PubMed Central

Guilford, Tim; Taylor, Graham K.

2014-01-01

Many animals, and birds in particular, are thought to use directional information from the sun in the form of a time-compensated sun compass, with predictably deviated orientation under clock shift being regarded as the litmus test of this. We suggest that this paradigm obscures a number of other ways in which solar-derived information could be important in animal orientation. We distinguish between the known use of the sun's azimuth to provide absolute geographical direction (compass mechanism) and its possible use to detect changes in heading (heading indicator mechanism). Just as in an aircraft, these two kinds of information may be provided by separate mechanisms and used for different functions, for example for navigation versus steering. We also argue that although a solar compass must be time-referenced to account for the sun's apparent diurnal movement, this need not entail full time compensation. This is because animals might also use time-dependent solar information in an associatively acquired, and hence time-limited, way. Furthermore, we show that a solar heading indicator, when used on a sufficiently short timescale, need not require time compensation at all. Finally, we suggest that solar-derived cues, such as shadows, could also be involved in navigation in ways that depend explicitly upon position, and are therefore not strictly compass-related. This could include giving directionality to landmarks, or acting as time-dependent landmarks involved in place recognition. We conclude that clock shift experiments alone are neither necessary nor sufficient to identify the occurrence of all conceivable uses of solar information in animal orientation, so that a predictable response to clock shift should not be regarded as an acid test of the use of solar information in navigation. PMID:25389374

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 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.

Helicopter Display Improvement Study

DTIC Science & Technology

1975-05-01

PRESSURE INDICATOR 43 TURN A N D SLIP INDICATOR 21 ENGINE AND SDG OIL IN TEMPERATURE INDICATOR 44 COURSE INDICATOR 22 RADIO MAGNETIC COMPASS INDICATOR... compass seemed to present a problem to several H-l series pilots In that It was poorly located and should be moved. Possible locations Included...the UH-lNs standby compass . Both H/L and L/L pilots agreed that internal, white light was the best system currently in use. INDIVIDUAL DISPLAYS

Scalable autonomous operations of unmanned assets

NASA Astrophysics Data System (ADS)

Jung, Sunghun

Although there have been great theoretical advances in the region of Unmanned Aerial Vehicle (UAV) autonomy, applications of those theories into real world are still hesitated due to unexpected disturbances. Most of UAVs which are currently used are mainly, strictly speaking, Remotely Piloted Vehicles (RPA) since most works related with the flight control, sensor data analysis, and decision makings are done by human operators. To increase the degree of autonomy, many researches are focused on developing Unmanned Autonomous Aerial Vehicle (UAAV) which can takeoff, fly to the interested area by avoiding unexpected obstacles, perform various missions with decision makings, come back to the base station, and land on by itself without any human operators. To improve the performance of UAVs, the accuracies of position and orientation sensors are enhanced by integrating a Unmanned Ground Vehicle (UGV) or a solar compass to a UAV; Position sensor accuracy of a GPS sensor on a UAV is improved by referencing the position of a UGV which is calculated by using three GPS sensors and Weighted Centroid Localization (WCL) method; Orientation sensor accuracy is improved as well by using Three Pixel Theorem (TPT) and integrating a solar compass which composed of nine light sensors to a magnetic compass. Also, improved health management of a UAV is fulfilled by developing a wireless autonomous charging station which uses four pairs of transmitter and receiver magnetic loops with four robotic arms. For the software aspect, I also analyze the error propagation of the proposed mission planning hierarchy to achieve the safest size of the buffer zone. In addition, among seven future research areas regarding UAV, this paper mainly focuses on developing algorithms of path planning, trajectory generation, and cooperative tactics for the operations of multiple UAVs using GA based multiple Traveling Salesman Problem (mTSP) which is solved by dividing into m number of Traveling Salesman Problems (TSP) using two region division methods such as Uniform Region Division (URD) and K-means Voronoi Region Division (KVRD). The topic of the maximum fuel efficiency is also dealt to ensure the minimum amount fuel consumption to perform surveillance on a given region using multiple UAVs. Last but not least, I present an application example of cattle roundup with two UAVs and two animals using the feedback linearization controller.

Incorporating Orienteering in School Programs.

ERIC Educational Resources Information Center

Bradford, Douglas

Orienteering has been described as being "either a serious sport, or a relaxing recreation". Orienteering can be a family affair or an individual fight against the clock. In its simplest form, orienteering can be described as a cross-country run, jog, or walk on a predetermined course, using a map and a compass to find several control points on…

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.

Love and compassion meditation: a nondual perspective.

PubMed

Josipovic, Zoran

2016-06-01

This paper discusses meditation from the unique perspective of the nondual approach and explores the possible relevance of this approach to applications of love and compassion meditation in clinical settings. It contrasts the nondual approach with the better known gradual or goal-oriented, dualistic view of meditation. This paper also introduces one of the central ideas of the nondual approach-that love and compassion, like other positive qualities that are ordinarily considered as goals of meditation practice, can be found to be already present within oneself as innate dimensions of one's authentic being. © 2016 New York Academy of Sciences.

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)

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.

Factors reducing the expected deflection in initial orientation in clock-shifted homing pigeons.

PubMed

Gagliardo, Anna; Odetti, Francesca; Ioalè, Paolo

2005-02-01

To orient from familiar sites, homing pigeons can rely on both an olfactory map and visual familiar landmarks. The latter can in principle be used in two different ways: either within a topographical map exploited for piloting or in a so-called mosaic map associated with a compass bearing. One way to investigate the matter is to put the compass and the topographical information in conflict by releasing clock-shifted pigeons from familiar locations. Although the compass orientation is in general dominant over a piloting strategy, a stronger or weaker tendency to correct towards the home direction by clock-shifted pigeons released from very familiar sites has often been observed. To investigate which factors are involved in the reduction of the deviation due to clock-shift, we performed a series of releases with intact and anosmic pigeons from familiar sites in unshifted and clock-shifted conditions and a series of releases from the same sites with naive clock-shifted birds. Our data suggest that the following factors have a role in reducing deviation due to the clock-shift: familiarity with the release site, the lack of olfactory information and some unknown site-dependent features.

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.

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.

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

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

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,…

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.

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.

Airport geomagnetic surveys in the United States

USGS Publications Warehouse

Berarducci, A.

2006-01-01

The Federal Aviation Administration (FAA) and the United States military have requirements for design, location, and construction of compass calibration pads (compass roses), these having been developed through collaboration with US Geological Survey (USGS) personnel. These requirements are detailed in the FAA Advisory Circular AC 150/5300-13, Appendix 4, and in various military documents, such as Handbook 1021/1, but the major requirement is that the range of declination measured within 75 meters of the center of a compass rose be less than or equal to 30 minutes of arc. The USGS Geomagnetism Group has developed specific methods for conducting a magnetic survey so that existing compass roses can be judged in terms of the needed standards and also that new sites can be evaluated for their suitability as potentially new compass roses. First, a preliminary survey is performed with a total-field magnetometer, with differences over the site area of less than 75nT being sufficient to warrant additional, more detailed surveying. Next, a number of survey points are established over the compass rose area and nearby, where declination is to be measured with an instrument capable of measuring declination to within 1 minute of arc, such as a Gurley transit magnetometer, DI Flux theodolite magnetometer, or Wild T-0. The data are corrected for diurnal and irregular effects of the magnetic field and declination is determined for each survey point, as well as declination range and average of the entire compass rose site. Altogether, a typical survey takes about four days to complete. ?? 2006 Springer.

Body image satisfaction and self-esteem in Thai female adolescents: the moderating role of self-compassion.

PubMed

Pisitsungkagarn, Kullaya; Taephant, Nattasuda; Attasaranya, Ploychompoo

2014-01-01

Body image satisfaction significantly influences self-esteem in female adolescents. Increased reports of lowered satisfaction in this population have raised concerns regarding their compromised self-esteem. This research study, therefore, sought to identify a culturally significant moderator of the association between body image satisfaction and self-esteem in Thai female adolescents. Orientation toward self-compassion, found to be particularly high in Thailand, was examined. A total of 302 Thai female undergraduates from three large public and private universities in the Bangkok metropolitan area responded to a set of questionnaires, which measured demographic information, body image satisfaction, self-compassion, and self-esteem. Data were analyzed using correlation and multiple regression analyses. Self-compassion was tested as a moderator of the relationship between body image satisfaction and self-esteem. Although its effect was relatively small, self-compassion significantly moderated the positive relationship between body image satisfaction and self-esteem. The relationship became less stringent for those with high self-compassion. The cultivation of self-compassion was recommended in female adolescents. In addition to moderating the association between body image satisfaction and self-esteem, the benefits to health and well-being of generalizing this cultivation are discussed.

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.

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

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

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.

Science Can Be Attractive.

ERIC Educational Resources Information Center

Leyden, Michael B.

1994-01-01

Discusses the properties of neodymium magnets and magnets in general and how magnets can be used to teach students important scientific principles, such as attraction, repulsion, and polarity; the role of magnetic forces in electronic communications and computers; the magnetic properties of the earth and compasses; and the relationship between…

Relative azimuth inversion by way of damped maximum correlation estimates

USGS Publications Warehouse

Ringler, A.T.; Edwards, J.D.; Hutt, C.R.; Shelly, F.

2012-01-01

Horizontal seismic data are utilized in a large number of Earth studies. Such work depends on the published orientations of the sensitive axes of seismic sensors relative to true North. These orientations can be estimated using a number of different techniques: SensOrLoc (Sensitivity, Orientation and Location), comparison to synthetics (Ekstrom and Busby, 2008), or by way of magnetic compass. Current methods for finding relative station azimuths are unable to do so with arbitrary precision quickly because of limitations in the algorithms (e.g. grid search methods). Furthermore, in order to determine instrument orientations during station visits, it is critical that any analysis software be easily run on a large number of different computer platforms and the results be obtained quickly while on site. We developed a new technique for estimating relative sensor azimuths by inverting for the orientation with the maximum correlation to a reference instrument, using a non-linear parameter estimation routine. By making use of overlapping windows, we are able to make multiple azimuth estimates, which helps to identify the confidence of our azimuth estimate, even when the signal-to-noise ratio (SNR) is low. Finally, our algorithm has been written as a stand-alone, platform independent, Java software package with a graphical user interface for reading and selecting data segments to be analyzed.

Development of Specific Aspects of Spirituality during a 6-Month Intensive Yoga Practice

PubMed Central

Büssing, Arndt; Hedtstück, Anemone; Khalsa, Sat Bir S.; Ostermann, Thomas; Heusser, Peter

2012-01-01

The majority of research on yoga focuses on its psychophysiological and therapeutic benefits, while the spiritual aspects are rarely addressed. Changes of specific aspects of spirituality were thus investigated among 160 individuals (91% women, mean age 40.9 ± 8.3 years; 57% Christians) starting a 2-year yoga teacher training. We used standardized questionnaires to measure aspects of spirituality (ASP), mindfulness (FMI—Freiburg Mindfulness Inventory), life satisfaction (BMLSS—Brief Multidimensional Life Satisfaction Scale), and positive mood (lightheartedness/relief). At the start of the course, scores of the respective ASP subscales for search for insight/wisdom, transcendence conviction, and conscious interactions/compassion were high, while those for religious orientation were low. Within the 6 month observation period, both conscious interactions/compassion (effect size, Cohen's d = .33), Religious orientation (d = .21), Lightheartedness/Relief (d = .75) and mindfulness (d = .53) increased significantly. Particularly non-religious/non-spiritual individuals showed moderate effects for an increase of conscious interactions/compassion. The results from this study suggest that an intensive yoga practice (1) may significantly increase specific aspects of practitioners' spirituality, mindfulness, and mood, (2) that these changes are dependent in part on their original spiritual/religious self-perception, and (3) that there are strong correlations amongst these constructs (i.e., conscious interactions/compassion, and mindfulness). PMID:22852023

A Fast 4-D TEM System for UXO Characterization

DTIC Science & Technology

2003-07-30

responses for a small conductive and permeable sphere. Magnetic permeability is the curve parameter. Figure 2.10: Compass/ Tiltmeter package...each TCM2 record. The DOS clock on the HP200LX was manually set to UTC each day using the UTC time displayed on the Figure 2.10: Compass/ Tiltmeter

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.

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.

Magnetic field sensor

NASA Astrophysics Data System (ADS)

Silva, Nicolas

2012-09-01

Earlier papers1-3 in this journal have described experiments on measuring the magnetic fields of current-carrying wires and permanent magnets using magnetic field probes of various kinds. This paper explains how to use an iPad and the free app MagnetMeter-3D Vector Magnetometer and Accelerometer4 (compass HD) to measure the magnetic fields.

Structural Orientations Adjacent to Some Colorado Geothermal Systems

DOE Data Explorer

Richard

2012-02-01

Structural orientations (fractures, joints, faults, lineaments, bedding orientations, etc.) were collected with a standard Brunton compass during routine field examinations of geothermal phenomena in Colorado. Often multiple orientations were taken from one outcrop. Care was taken to ensure outcrops were "in place". Point data was collected with a hand-held GPS unit. The structural data is presented both as standard quadrant measurements and in format suitable for ESRI symbology

Web-Based Software for Managing Research

NASA Technical Reports Server (NTRS)

Hoadley, Sherwood T.; Ingraldi, Anthony M.; Gough, Kerry M.; Fox, Charles; Cronin, Catherine K.; Hagemann, Andrew G.; Kemmerly, Guy T.; Goodman, Wesley L.

2007-01-01

aeroCOMPASS is a software system, originally designed to aid in the management of wind tunnels at Langley Research Center, that could be adapted to provide similar aid to other enterprises in which research is performed in common laboratory facilities by users who may be geographically dispersed. Included in aeroCOMPASS is Web-interface software that provides a single, convenient portal to a set of project- and test-related software tools and other application programs. The heart of aeroCOMPASS is a user-oriented document-management software subsystem that enables geographically dispersed users to easily share and manage a variety of documents. A principle of "write once, read many" is implemented throughout aeroCOMPASS to eliminate the need for multiple entry of the same information. The Web framework of aeroCOMPASS provides links to client-side application programs that are fully integrated with databases and server-side application programs. Other subsystems of aeroCOMPASS include ones for reserving hardware, tracking of requests and feedback from users, generating interactive notes, administration of a customer-satisfaction questionnaire, managing execution of tests, managing archives of metadata about tests, planning tests, and providing online help and instruction for users.

Unraveling navigational strategies in migratory insects

PubMed Central

Merlin, Christine; Heinze, Stanley; Reppert, Steven M.

2011-01-01

Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied directional strategy relies on a time-compensated sun compass, used by diurnal insects, for which neural circuits have begun to be delineated. Yet, a growing body of evidence suggests that migratory insects may also rely on other compasses that use night sky cues or the Earth's magnetic field. Those mechanisms are ripe for exploration. PMID:22154565

Measuring Earth's Magnetic Field Simply.

ERIC Educational Resources Information Center

Stewart, Gay B.

2000-01-01

Describes a method for measuring the earth's magnetic field using an empty toilet paper tube, copper wire, clear tape, a battery, a linear variable resistor, a small compass, cardboard, a protractor, and an ammeter. (WRM)

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.

FY87 Evaluation of Shipboard Electro-Optical Apparatus for Use in Law Enforcement and Search.

DTIC Science & Technology

1987-12-01

track, toward B-5 Cuban waters. M/V Esjoci’s master requested course--may be having compass problems. Coast Guard Officer of the Deck told him to steer...Inspeced. NCICS: MACHINERYC111 0 N jiSu[MIhE DRL$ AN TAI Olw f nS it SDg ~. (’ATGUR O WAHROBEVTONAOOERTOA SUEkARsi ySE T L tl Ten,_ _ r. 1 , D( .I _j U ,_6...bridge six feet from our magnetic compass . The FLIR’s proximity to the compass caused approximately eight degrees deviation when energized. It also

Coherent triplet excitation suppresses the heading error of the avian compass

NASA Astrophysics Data System (ADS)

Katsoprinakis, G. E.; Dellis, A. T.; Kominis, I. K.

2010-08-01

Radical-ion pair reactions are currently understood to underlie the biochemical magnetic compass of migratory birds. It was recently shown that radical-ion pair reactions form a rich playground for the application of quantum-information-science concepts and effects. We will show here that the intricate interplay between the quantum Zeno effect and the coherent excitation of radical-ion pairs leads to an exquisite angular sensitivity of the reaction yields. This results in a significant and previously unanticipated suppression of the avian compass heading error, opening the way to quantum engineering precision biological sensors.

Unraveling navigational strategies in migratory insects.

PubMed

Merlin, Christine; Heinze, Stanley; Reppert, Steven M

2012-04-01

Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied directional strategy relies on a time-compensated sun compass, used by diurnal insects, for which neural circuits have begun to be delineated. Yet, a growing body of evidence suggests that migratory insects may also rely on other compasses that use night sky cues or the Earth's magnetic field. Those mechanisms are ripe for exploration. Copyright © 2011 Elsevier Ltd. All rights reserved.

Wealth, Poverty, and Happiness: Social Class Is Differentially Associated With Positive Emotions.

PubMed

Piff, Paul K; Moskowitz, Jake P

2017-12-18

Is higher social class associated with greater happiness? In a large nationally representative U.S. sample (N = 1,519), we examined the association between social class (household income) and self-reported tendencies to experience 7 distinct positive emotions that are core to happiness: amusement, awe, compassion, contentment, enthusiasm, love, and pride. Consistent with past research indicating that social class underlies differential patterns of attending to the self versus orienting to others, higher social class was associated with greater self-oriented feelings of contentment and pride, and with greater amusement. In contrast, lower social class was associated with more other-oriented feelings of compassion and love, and with greater awe. There were no class differences in enthusiasm. We discuss that individuals from different social class backgrounds may exhibit different patterns of emotional responding due to their distinct social concerns and priorities. Whereas self-oriented emotions may follow from, foster, and reinforce upper class individuals' desire for independence and self-sufficiency, greater other-oriented emotion may enable lower class individuals to form more interdependent bonds to cope with their more threatening environments. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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.

50 CFR 648.84 - Gear-marking requirements and gear restrictions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... magnetic south through west to, and including, north) of the gear displays a standard 12-inch (30.5-cm.... The easternmost end (meaning the half compass circle from magnetic north through east to, and...

Spin relaxation of radicals in cryptochrome and its role in avian magnetoreception

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

Worster, Susannah; Kattnig, Daniel R.; Hore, P. J., E-mail: peter.hore@chem.ox.ac.uk

2016-07-21

Long-lived spin coherence and rotationally ordered radical pairs have previously been identified as key requirements for the radical pair mechanism of the avian magnetic compass sense. Both criteria are hard to meet in a biological environment, where thermal motion of the radicals creates dynamic disorder and drives efficient spin relaxation. This has long been cited as a major stumbling block of the radical pair hypothesis. Here we combine Redfield relaxation theory with analytical solutions to a rotational diffusion equation to assess the impact of restricted rotational motion of the radicals on the operation of the compass. The effects of suchmore » motions are first investigated generally in small, model systems and are then critically examined in the magnetically sensitive flavin-tryptophan radical pair that is formed photochemically in the proposed magnetoreceptor protein, cryptochrome. We conclude that relaxation is slowest when rotational motion of the radicals within the protein is fast and highly constrained; that in a regime of slow relaxation, the motional averaging of hyperfine interactions has the potential to improve the sensitivity of the compass; and that consideration of motional effects can significantly alter the design criteria for an optimal compass. In addition, we demonstrate that motion of the flavin radical is likely to be compatible with its role as a component of a functioning radical-pair compass, whereas the motion of the tryptophan radical is less ideal, unless it is particularly fast.« less

A Simple Demonstration of a General Rule for the Variation of Magnetic Field with Distance

ERIC Educational Resources Information Center

Kodama, K.

2009-01-01

We describe a simple experiment demonstrating the variation in magnitude of a magnetic field with distance. The method described requires only an ordinary magnetic compass and a permanent magnet. The proposed graphical analysis illustrates a unique method for deducing a general rule of magnetostatics. (Contains 1 table and 6 figures.)

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

Inhomogeneous ensembles of radical pairs in chemical compasses

PubMed Central

Procopio, Maria; Ritz, Thorsten

2016-01-01

The biophysical basis for the ability of animals to detect the geomagnetic field and to use it for finding directions remains a mystery of sensory biology. One much debated hypothesis suggests that an ensemble of specialized light-induced radical pair reactions can provide the primary signal for a magnetic compass sensor. The question arises what features of such a radical pair ensemble could be optimized by evolution so as to improve the detection of the direction of weak magnetic fields. Here, we focus on the overlooked aspect of the noise arising from inhomogeneity of copies of biomolecules in a realistic biological environment. Such inhomogeneity leads to variations of the radical pair parameters, thereby deteriorating the signal arising from an ensemble and providing a source of noise. We investigate the effect of variations in hyperfine interactions between different copies of simple radical pairs on the directional response of a compass system. We find that the choice of radical pair parameters greatly influences how strongly the directional response of an ensemble is affected by inhomogeneity. PMID:27804956

Inhomogeneous ensembles of radical pairs in chemical compasses

NASA Astrophysics Data System (ADS)

Procopio, Maria; Ritz, Thorsten

2016-11-01

The biophysical basis for the ability of animals to detect the geomagnetic field and to use it for finding directions remains a mystery of sensory biology. One much debated hypothesis suggests that an ensemble of specialized light-induced radical pair reactions can provide the primary signal for a magnetic compass sensor. The question arises what features of such a radical pair ensemble could be optimized by evolution so as to improve the detection of the direction of weak magnetic fields. Here, we focus on the overlooked aspect of the noise arising from inhomogeneity of copies of biomolecules in a realistic biological environment. Such inhomogeneity leads to variations of the radical pair parameters, thereby deteriorating the signal arising from an ensemble and providing a source of noise. We investigate the effect of variations in hyperfine interactions between different copies of simple radical pairs on the directional response of a compass system. We find that the choice of radical pair parameters greatly influences how strongly the directional response of an ensemble is affected by inhomogeneity.

Sky Luminaries in the Space Orienting Activity of Homo Sapiens in the Middle Palaeolithic

NASA Astrophysics Data System (ADS)

Kaurov, E. N.

Data describing the beginnings of the space orienting activity of Homo sapiens is analysed and systematized: observation of the Pole and the recognition of Ursa Major were used as the basis of the determination of the points of the compass. Data and results from astronomy, history of astronomy, archaeology and palaeoanthropology were used for the reconstruction of the evolution of the space orienting activity of Homo sapiens.

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.

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.

Can invertebrates see the e-vector of polarization as a separate modality of light?

PubMed

Labhart, Thomas

2016-12-15

The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, 'color-blind' humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert 'water below!' to water-seeking bugs. © 2016. Published by The Company of Biologists Ltd.

Can invertebrates see the e-vector of polarization as a separate modality of light?

PubMed Central

2016-01-01

ABSTRACT The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, ‘color-blind’ humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert ‘water below!’ to water-seeking bugs. PMID:27974532

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.

A high accuracy magnetic heading system composed of fluxgate magnetometers and a microcomputer

NASA Astrophysics Data System (ADS)

Liu, Sheng-Wu; Zhang, Zhao-Nian; Hung, James C.

The authors present a magnetic heading system consisting of two fluxgate magnetometers and a single-chip microcomputer. The system, when compared to gyro compasses, is smaller in size, lighter in weight, simpler in construction, quicker in reaction time, free from drift, and more reliable. Using a microcomputer in the system, heading error due to compass deviation, sensor offsets, scale factor uncertainty, and sensor tilts can be compensated with the help of an error model. The laboratory test of a typical system showed that the accuracy of the system was improved from more than 8 deg error without error compensation to less than 0.3 deg error with compensation.

Orienteering with Adventure Education: New Games for the 21st Century

ERIC Educational Resources Information Center

Hammes, Ryan

2007-01-01

Orienteering is an outdoor pursuit in which participants try to locate a series of different control points, using only a map and compass (Laubach, 1998). It is a life-long skill that can be taught to all ages in both a natural and urban setting. Adventure education is an approach to teaching where an individual is placed in an unfamiliar…

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

Electromagnetic Induction with Neodymium Magnets

ERIC Educational Resources Information Center

Wood, Deborah; Sebranek, John

2013-01-01

In April 1820, Hans Christian Ørsted noticed that the needle of a nearby compass deflected briefly from magnetic north each time the electric current of the battery he was using for an unrelated experiment was turned on or off. Upon further investigation, he showed that an electric current flowing through a wire produces a magnetic field. In 1831…

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...

Chemical magnetoreception in birds: The radical pair mechanism

PubMed Central

Rodgers, Christopher T.; Hore, P. J.

2009-01-01

Migratory birds travel vast distances each year, finding their way by various means, including a remarkable ability to perceive the Earth's magnetic field. Although it has been known for 40 years that birds possess a magnetic compass, avian magnetoreception is poorly understood at all levels from the primary biophysical detection events, signal transduction pathways and neurophysiology, to the processing of information in the brain. It has been proposed that the primary detector is a specialized ocular photoreceptor that plays host to magnetically sensitive photochemical reactions having radical pairs as fleeting intermediates. Here, we present a physical chemist's perspective on the “radical pair mechanism” of compass magnetoreception in birds. We outline the essential chemical requirements for detecting the direction of an Earth-strength ≈50 μT magnetic field and comment on the likelihood that these might be satisfied in a biologically plausible receptor. Our survey concludes with a discussion of cryptochrome, the photoactive protein that has been put forward as the magnetoreceptor molecule. PMID:19129499

Emlen funnel experiments revisited: methods update for studying compass orientation in songbirds.

PubMed

Bianco, Giuseppe; Ilieva, Mihaela; Veibäck, Clas; Öfjäll, Kristoffer; Gadomska, Alicja; Hendeby, Gustaf; Felsberg, Michael; Gustafsson, Fredrik; Åkesson, Susanne

2016-10-01

Migratory songbirds carry an inherited capacity to migrate several thousand kilometers each year crossing continental landmasses and barriers between distant breeding sites and wintering areas. How individual songbirds manage with extreme precision to find their way is still largely unknown. The functional characteristics of biological compasses used by songbird migrants has mainly been investigated by recording the birds directed migratory activity in circular cages, so-called Emlen funnels. This method is 50 years old and has not received major updates over the past decades. The aim of this work was to compare the results from newly developed digital methods with the established manual methods to evaluate songbird migratory activity and orientation in circular cages.We performed orientation experiments using the European robin ( Erithacus rubecula ) using modified Emlen funnels equipped with thermal paper and simultaneously recorded the songbird movements from above. We evaluated and compared the results obtained with five different methods. Two methods have been commonly used in songbirds' orientation experiments; the other three methods were developed for this study and were based either on evaluation of the thermal paper using automated image analysis, or on the analysis of videos recorded during the experiment.The methods used to evaluate scratches produced by the claws of birds on the thermal papers presented some differences compared with the video analyses. These differences were caused mainly by differences in scatter, as any movement of the bird along the sloping walls of the funnel was recorded on the thermal paper, whereas video evaluations allowed us to detect single takeoff attempts by the birds and to consider only this behavior in the orientation analyses. Using computer vision, we were also able to identify and separately evaluate different behaviors that were impossible to record by the thermal paper.The traditional Emlen funnel is still the most used method to investigate compass orientation in songbirds under controlled conditions. However, new numerical image analysis techniques provide a much higher level of detail of songbirds' migratory behavior and will provide an increasing number of possibilities to evaluate and quantify specific behaviors as new algorithms will be developed.

Detection of Magnetic Field Intensity Gradient by Homing Pigeons (Columba livia) in a Novel “Virtual Magnetic Map” Conditioning Paradigm

PubMed Central

Mora, Cordula V.; Bingman, Verner P.

2013-01-01

It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a “virtual magnetic map” during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain. PMID:24039812

Detection of magnetic field intensity gradient by homing pigeons (Columba livia) in a novel "virtual magnetic map" conditioning paradigm.

PubMed

Mora, Cordula V; Bingman, Verner P

2013-01-01

It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a "virtual magnetic map" during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain.

Navigational Mechanisms of Migrating Monarch Butterflies

PubMed Central

Reppert, Steven M.; Gegear, Robert J.; Merlin, Christine

2010-01-01

Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind the navigation south, using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and likely integrated in the brain’s central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs may also use a magnetic compass, because they possess two cryptochromes that have the molecular capability for light-dependent magnetoreception. Multiple genomic approaches are being utilized to ultimately identify navigation genes. Monarch butterflies are thus emerging as an excellent model organism to study the molecular and neural basis of long-distance migration. PMID:20627420

(abstract) Realization of a Faster, Cheaper, Better Mission and Its New Paradigm Star Tracker, the Advanced Stellar Compass

NASA Technical Reports Server (NTRS)

Eisenman, Allan Read; Liebe, Carl Christian; Joergensen, John Lief; Jensen, Gunnar Bent

1997-01-01

The first Danish satellite, rsted, will be launched in August of 1997. The scientific objective of sted is to perform a precision mapping of the Earth's magnetic field. Attitude data for the payload and the satellite are provided by the Advanced Stellar Compass (ASC) star tracker. The ASC consists of a CCD star camera and a capable microprocessor which operates by comparing the star image frames taken by the camera to its internal star catalogs.

Generation of noninductive current by electron-Bernstein waves on the COMPASS-D Tokamak.

PubMed

Shevchenko, V; Baranov, Y; O'Brien, M; Saveliev, A

2002-12-23

Electron-Bernstein waves (EBW) were excited in the plasma by mode converted extraordinary (X) waves launched from the high field side of the COMPASS-D tokamak at different toroidal angles. It has been found experimentally that X-mode injection perpendicular to the magnetic field provides maximum heating efficiency. Noninductive currents of up to 100 kA were found to be driven by the EBW mode with countercurrent drive. These results are consistent with ray tracing and quasilinear Fokker-Planck simulations.

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.

Anchor Node Localization for Wireless Sensor Networks Using Video and Compass Information Fusion

PubMed Central

Pescaru, Dan; Curiac, Daniel-Ioan

2014-01-01

Distributed sensing, computing and communication capabilities of wireless sensor networks require, in most situations, an efficient node localization procedure. In the case of random deployments in harsh or hostile environments, a general localization process within global coordinates is based on a set of anchor nodes able to determine their own position using GPS receivers. In this paper we propose another anchor node localization technique that can be used when GPS devices cannot accomplish their mission or are considered to be too expensive. This novel technique is based on the fusion of video and compass data acquired by the anchor nodes and is especially suitable for video- or multimedia-based wireless sensor networks. For these types of wireless networks the presence of video cameras is intrinsic, while the presence of digital compasses is also required for identifying the cameras' orientations. PMID:24594614

Experimental Protein Structure Verification by Scoring with a Single, Unassigned NMR Spectrum.

PubMed

Courtney, Joseph M; Ye, Qing; Nesbitt, Anna E; Tang, Ming; Tuttle, Marcus D; Watt, Eric D; Nuzzio, Kristin M; Sperling, Lindsay J; Comellas, Gemma; Peterson, Joseph R; Morrissey, James H; Rienstra, Chad M

2015-10-06

Standard methods for de novo protein structure determination by nuclear magnetic resonance (NMR) require time-consuming data collection and interpretation efforts. Here we present a qualitatively distinct and novel approach, called Comparative, Objective Measurement of Protein Architectures by Scoring Shifts (COMPASS), which identifies the best structures from a set of structural models by numerical comparison with a single, unassigned 2D (13)C-(13)C NMR spectrum containing backbone and side-chain aliphatic signals. COMPASS does not require resonance assignments. It is particularly well suited for interpretation of magic-angle spinning solid-state NMR spectra, but also applicable to solution NMR spectra. We demonstrate COMPASS with experimental data from four proteins--GB1, ubiquitin, DsbA, and the extracellular domain of human tissue factor--and with reconstructed spectra from 11 additional proteins. For all these proteins, with molecular mass up to 25 kDa, COMPASS distinguished the correct fold, most often within 1.5 Å root-mean-square deviation of the reference structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental Protein Structure Verification by Scoring with a Single, Unassigned NMR Spectrum

PubMed Central

Courtney, Joseph M.; Ye, Qing; Nesbitt, Anna E.; Tang, Ming; Tuttle, Marcus D.; Watt, Eric D.; Nuzzio, Kristin M.; Sperling, Lindsay J.; Comellas, Gemma; Peterson, Joseph R.; Morrissey, James H.; Rienstra, Chad M.

2016-01-01

Standard methods for de novo protein structure determination by nuclear magnetic resonance (NMR) require time-consuming data collection and interpretation efforts. Here we present a qualitatively distinct and novel approach, called Comparative, Objective Measurement of Protein Architectures by Scoring Shifts (COMPASS), which identifies the best structures from a set of structural models by numerical comparison with a single, unassigned 2D 13C-13C NMR spectrum containing backbone and side-chain aliphatic signals. COMPASS does not require resonance assignments. It is particularly well suited for interpretation of magic-angle spinning solid-state NMR spectra, but also applicable to solution NMR spectra. We demonstrate COMPASS with experimental data from four proteins—GB1, ubiquitin, DsbA, and the extracellular domain of human tissue factor—and with reconstructed spectra from 11 additional proteins. For all these proteins, with molecular mass up to 25 kDa, COMPASS distinguished the correct fold, most often within 1.5 Å root-mean-square deviation of the reference structure. PMID:26365800

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.

Sensory augmentation: integration of an auditory compass signal into human perception of space

PubMed Central

Schumann, Frank; O’Regan, J. Kevin

2017-01-01

Bio-mimetic approaches to restoring sensory function show great promise in that they rapidly produce perceptual experience, but have the disadvantage of being invasive. In contrast, sensory substitution approaches are non-invasive, but may lead to cognitive rather than perceptual experience. Here we introduce a new non-invasive approach that leads to fast and truly perceptual experience like bio-mimetic techniques. Instead of building on existing circuits at the neural level as done in bio-mimetics, we piggy-back on sensorimotor contingencies at the stimulus level. We convey head orientation to geomagnetic North, a reliable spatial relation not normally sensed by humans, by mimicking sensorimotor contingencies of distal sounds via head-related transfer functions. We demonstrate rapid and long-lasting integration into the perception of self-rotation. Short training with amplified or reduced rotation gain in the magnetic signal can expand or compress the perceived extent of vestibular self-rotation, even with the magnetic signal absent in the test. We argue that it is the reliability of the magnetic signal that allows vestibular spatial recalibration, and the coding scheme mimicking sensorimotor contingencies of distal sounds that permits fast integration. Hence we propose that contingency-mimetic feedback has great potential for creating sensory augmentation devices that achieve fast and genuinely perceptual experiences. PMID:28195187

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.

75 FR 67639 - Airworthiness Directives; Piaggio Aero Industries S.p.A Model PIAGGIO P-180 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-03

...: Compass mismatch (up to loss of heading information) were reported by operators, due to ferro-magnetic... invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed..., due to ferro-magnetic masses (like the telescopic Tow-Bar) stowed in the baggage compartment. A...

From Compass to Hard Drive--Integrated Activities for Studying Magnets

ERIC Educational Resources Information Center

Dean, J.; Allwood, D. A.

2014-01-01

We describe a range of practical activities that allows students to investigate the properties and applications of magnets. The activities can be used in isolation or used together to build a rounded understanding of the subject area. The activities include simple demonstrations using common or inexpensive equipment, hands-on experiments for small…

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.

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.

Secure attachment and eudaimonic well-being in late adulthood: The mediating role of self-compassion.

PubMed

Homan, Kristin J

2018-03-01

Attachment style refers to a systematic pattern of emotions, behaviors, and expectations that people have for how others will respond in relationships. Extensive evidence has documented the importance of attachment security in infants, children, adolescents, and adults, but the effects of attachment among exclusively older adult populations have received less attention. The present study explored the relationships between attachment style in late adulthood and eudaimonic well-being, which refers to a life replete with meaning, productive activity, and striving to reach one's potential. It also explored the mediating role of self-compassion, which can be described as a kind and forgiving attitude toward the self. A sample of 126 community-dwelling older adults (mean age = 70.40 years) completed measures tapping adult attachment, self-compassion, and six theoretically derived markers of eudaimonic well-being. Attachment anxiety and avoidance were inversely related to self-acceptance, personal growth, interpersonal relationship quality, purpose in life, and environmental mastery. Mediation analyses showed that self-compassion mediated each of these relationships. Results support the importance of attachment orientation for psychological well-being in late life and indicate that secure attachment facilitates an attitude of kindness and acceptance toward the self.

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...

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.

Navigational mechanisms of migrating monarch butterflies.

PubMed

Reppert, Steven M; Gegear, Robert J; Merlin, Christine

2010-09-01

Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind their southward navigation while using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and are probably integrated in the brain's central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs might also use a magnetic compass because they possess two cryptochromes that have the molecular capability for light-dependent magnetoreception. Multiple genomic approaches are now being used with the aim of identifying navigation genes. Monarch butterflies are thus emerging as an excellent model organism in which to study the molecular and neural basis of long-distance migration. Copyright 2010 Elsevier Ltd. All rights reserved.

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.

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

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.

Extending Learning beyond the Classroom.

ERIC Educational Resources Information Center

Gray, Gary

1994-01-01

Sixth graders at Kamehameha Elementary School ascended a high mountain peak, successfully orienting themselves for over 5 miles using topographical maps and compasses and the knowledge, skills, and attitudes acquired at school. The article describes the program, noting the knowledge and tools students used to accomplish their goal. (SM)

Improving LADCP Velocity Profiles with External Attitude Sensors

NASA Astrophysics Data System (ADS)

Thurnherr, A. M.; Goszczko, I.

2016-12-01

Data collected with Acoustic Doppler Current Profilers installed on CTD rosettes and lowered through the water column (LADCP systems) are routinely used to derive full-depth profiles of ocean velocity. In addition to the uncertainties arising from random noise in the along-beam velocity measurements, LADCP derived velocities are commonly contaminated by bias errors due to imperfectly measured instrument attitude (pitch, roll and heading). Of particular concern are the heading measurements because it is not usually feasible to calibrate the internal ADCP compasses with the instruments installed on a CTD rosette, away from the magnetic disturbances of the ship as well as the current-carrying winch wire. Heading data from dual-headed LADCP systems, which consist of upward and downward-pointing ADCPs installed on the same rosette, commonly indicate heading-dependent compass errors with amplitudes exceeding 10 degrees. In an attempt to reduce LADCP velocity errors, over 200 full-depth profiles were collected during several recent projects, including GO-SHIP, DIMES and ECOGIG, with an inexpensive (<$200) external magnetometer/accelerometer package. The resulting data permit full compass calibrations (for both hard- and soft-iron effects) from in-situ profile data and yields improved pitch and roll measurements. Results indicate greatly reduced inconsistencies between the data from the two ADCPs (horizontal-velocity processing residuals), as well as smaller biases in vertical -velocity (w) measurements. In addition, the external magnetometer package allows processing of some LADCP data collected in regions where the horizontal magnitude of the earth's magnetic field is insufficient for the ADCPs internal compasses to work at all.

A moral profession.

PubMed

Newham, Roger; Terry, Louise; Atherley, Siobhan; Hahessy, Sinead; Babenko-Mould, Yolanda; Evans, Marilyn; Ferguson, Karen; Carr, Graham; Cedar, S H

2017-01-01

Lack of compassion is claimed to result in poor and sometimes harmful nursing care. Developing strategies to encourage compassionate caring behaviours are important because there is evidence to suggest a connection between having a moral orientation such as compassion and resulting caring behaviour in practice. This study aimed to articulate a clearer understanding of compassionate caring via nurse educators' selection and use of published texts and film. This study employed discourse analysis. Participants and research context: A total of 41 nurse educators working in universities in the United Kingdom (n = 3), Ireland (n = 1) and Canada (n = 1) completed questionnaires on the narratives that shaped their understanding of care and compassion. The desire to understand others and how to care compassionately characterised educators' choices. Most narratives were examples of kindness and compassion. A total of 17 emphasised the importance of connecting with others as a central component of compassionate caring, 10 identified the burden of caring, 24 identified themes of abandonment and of failure to see the suffering person and 15 narratives showed a discourse of only showing compassion to those 'deserving' often understood as the suffering person doing enough to help themselves. These findings are mostly consistent with work in moral philosophy emphasising the particular or context and perception or vision as well as the necessity of emotions. The narratives themselves are used by nurse educators to help explicate examples of caring and compassion (or its lack). To feel cared about people need to feel 'visible' as though they matter. Nurses need to be alert to problems that may arise if their 'moral vision' is influenced by ideas of desert and how much the patient is doing to help himself or herself.

New directional results and determination of absolute archaeointensity using both the classical Thellier and the multi-specimen procedures for two kilns excavated at Osterietta, Italy

NASA Astrophysics Data System (ADS)

Tema, Evdokia; Camps, Pierre; Ferrara, Enzo

2014-05-01

A detailed rock-magnetic and archaeomagnetic study has been carried out on two rescue excavation kilns discovered during the works to expand a highway at the location of Osterietta, in Northen Italy. Systematic archaeomagnetic sampling was carried out collecting 15 samples from the first kiln (OSA) and 8 samples from the second kiln (OSB), all of them oriented in situ with a magnetic compass and an inclinometer. Magnetic mineralogy measurements have been carried out in order to determine the main magnetic carrier of the samples and to check their thermal stability. Standard thermal demagnetization procedures have been used to determine the archaeomagnetic direction registered by the bricks during their last firing. Demagnetization results show a very stable characteristic remanent magnetization (ChRM). We averaged the directions for each kiln separately and calculated the statistical parameters assuming a Fisherian distribution. The archaeointensity of both kilns has also been recovered with both the classical Thellier-Thellier method and the multi-specimen procedure (MSP-DSC). During the Thellier experiments, regular partial thermoremanent magnetization checks have been performed and the effect of the anisotropy of the thermoremanent magnetization (TRM) and cooling rate upon TRM intensity acquisition have been investigated in all samples. The multi-specimen procedure was performed with a very fast-heating oven developed at Montpellier (France). The intensity results obtained from both methods have been compared and the full geomagnetic field vector determined for each kiln has been used for archaeomagnetic dating. The obtained results show that the kilns were almost contemporaneous and their last use occurred in the 1750-1850 AD time interval.

Personality traits associated with genetic counselor compassion fatigue: the roles of dispositional optimism and locus of control.

PubMed

Injeyan, Marie C; Shuman, Cheryl; Shugar, Andrea; Chitayat, David; Atenafu, Eshetu G; Kaiser, Amy

2011-10-01

Compassion fatigue (CMF) arises as a consequence of secondary exposure to distress and can be elevated in some health practitioners. Locus of control and dispositional optimism are aspects of personality known to influence coping style. To investigate whether these personality traits influence CMF risk, we surveyed 355 genetic counselors about their CMF, locus of control orientation, and degree of dispositional optimism. Approximately half of respondents reported they experience CMF; 26.6% had considered leaving their job due to CMF symptoms. Mixed-method analyses revealed that genetic counselors having an external locus of control and low optimism were at highest risk for CMF. Those at highest risk experienced moderate-to-high burnout, low-to-moderate compassion satisfaction, and tended to rely on religion/spirituality when coping with stress. CMF risk was not influenced by years in practice, number of genetic counselor colleagues in the workplace, or completion of graduate training in this area. Recommendations for practice and education are outlined.

The calm before the storm? Burnout and compassion fatigue among undergraduate nursing students.

PubMed

Michalec, Barret; Diefenbeck, Cynthia; Mahoney, Margaret

2013-04-01

Studies have consistently highlighted the deleterious impact of burnout and compassion fatigue on professional nurses' well-being and willingness to remain in the profession. Yet, as to what extent these noxious conditions are suffered among nursing students is still unclear. In this study 436 undergraduate nursing students completed surveys assessing their experiences of emotional exhaustion, depersonalization, lack of personal accomplishment, burnout, secondary traumatic stress, and compassion satisfaction (factors of burnout and compassion fatigue). There were no significant differences found between 3rd and 4th year students' reports of detrimental conditions and those of the 1st or 2nd year students. Furthermore, 4th year students reported significantly higher levels of personal accomplishment compared to 1st and 2nd year students. Semi-structured in-depth interviews with 3rd and 4th year students revealed that their clinical exposure during these years (especially during the 4th year) may enhance their other-orientation as well as promote role actualization, which may serve as protective features. Students did, however, express concern regarding an inevitable onset of burnout at some point during their professional careers. It is suggested that a key to understanding the onset and experience of burnout and compassion fatigue among nurses is to continue to examine the transition from student to professional nurse and the cultural atmosphere of nursing education compared to professional practice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sampling methods in archaeomagnetic dating: A comparison using case studies from Wörterberg, Eisenerz and Gams Valley (Austria)

NASA Astrophysics Data System (ADS)

Trapanese, A.; Batt, C. M.; Schnepp, E.

The aim of this research was to review the relative merits of different methods of taking samples for archaeomagnetic dating. To allow different methods to be investigated, two archaeological structures and one modern fireplace were sampled in Austria. On each structure a variety of sampling methods were used: the tube and disc techniques of Clark et al. (Clark, A.J., Tarling, D.H., Noel, M., 1988. Developments in archaeomagnetic dating in Great Britain. Journal of Archaeological Science 15, 645-667), the drill core technique, the mould plastered hand block method of Thellier, and a modification of it. All samples were oriented with a magnetic compass and sun compass, where weather conditions allowed. Approximately 12 discs, tubes, drill cores or plaster hand blocks were collected from each structure, with one mould plaster hand block being collected and cut into specimens. The natural remanent magnetisation (NRM) of the samples was measured and stepwise alternating field (AF) or thermal demagnetisation was applied. Samples were measured either in the UK or in Austria, which allowed the comparison of results between magnetometers with different sensitivity. The tubes and plastered hand block specimens showed good agreement in directional results, and the samples obtained showed good stability. The discs proved to be unreliable as both NRM and the characteristic remanent magnetisation (ChRM) distribution were very scattered. The failure of some methods may be related to the suitability of the material sampled, for example if it was disturbed before sampling, had been insufficiently heated or did not contain appropriate magnetic minerals to retain a remanent magnetisation. Caution is also recommended for laboratory procedures as the cutting of poorly consolidated specimens may disturb the material and therefore the remanent magnetisation. Criteria and guidelines were established to aid researchers in selecting the most appropriate method for a particular archaeological structure.

Terrain Models in Field Geology Courses.

ERIC Educational Resources Information Center

Whittecar, G. Richard

1984-01-01

Describes a terrain model for geologic mapping which, when combined with exercises in rock description, Brunton compass manipulation, orienteering, and geologic report writing, allows students to refine skills needed for summer field camp. Advantages and limitations of the model and its use in a field course are also discussed. (BC)

Get Your Bearings

ERIC Educational Resources Information Center

Teaching Pre K-8, 2004

2004-01-01

This article describes an outdoor activity known as orienteering, the practice of using a map and a compass to find points in a landscape. Downloadable materials, courtesy of The Roger Tory Peterson Institute, can be found on www.TeachingK-8.com. These materials include instructions for the activity and reproducible illustrations of seven basic…

A Matter of Course.

ERIC Educational Resources Information Center

Livingston, Becca

This paper argues for an educational orientation to American studies in high school that contributes toward individual growth and a sense of compassion toward humanity. According to the author, conventional schooling is a process of training youth to fit into out society by internalizing the accepted behavior and attitudinal norms. The student…

To Excel at "O," Study the Map and Run Like Hell.

ERIC Educational Resources Information Center

Conniff, Richard

1992-01-01

Explains the sport of orienteering in which participants use detailed topographic maps and compasses to reach control points along a course. Describes the history of the sport and its minimal success in the United States. Presents several versions of the sport and identifies the demographics of participants. (KS)

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.

Declinazione magnetica: storia delle prime misure e misura con l'azimut del Sole

NASA Astrophysics Data System (ADS)

Sigismondi, Costantino

2016-05-01

The magnetic declination is the compass deviation from astronomical North. Georg Hartmann in 1510 in Rome firstly measured it as 6° East. Using accurate solar ephemerides and a UTC synchronized watch, the shadow of a vertical pole is astronomically referenced. The angles of a 10m size triangle including the direction of this shadow, the solar azimuth, and the magnetic North give the magnetic declination with an accuracy of 2 arcmin.

Introducing minimum Fisher regularisation tomography to AXUV and soft x-ray diagnostic systems of the COMPASS tokamak

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

Mlynar, J.; Weinzettl, V.; Imrisek, M.

2012-10-15

The contribution focuses on plasma tomography via the minimum Fisher regularisation (MFR) algorithm applied on data from the recently commissioned tomographic diagnostics on the COMPASS tokamak. The MFR expertise is based on previous applications at Joint European Torus (JET), as exemplified in a new case study of the plasma position analyses based on JET soft x-ray (SXR) tomographic reconstruction. Subsequent application of the MFR algorithm on COMPASS data from cameras with absolute extreme ultraviolet (AXUV) photodiodes disclosed a peaked radiating region near the limiter. Moreover, its time evolution indicates transient plasma edge cooling following a radial plasma shift. In themore » SXR data, MFR demonstrated that a high resolution plasma positioning independent of the magnetic diagnostics would be possible provided that a proper calibration of the cameras on an x-ray source is undertaken.« less

78 FR 72061 - Notice of Petitions by Firms for Determination of Eligibility To Apply for Trade Adjustment...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

.... magnetic compass sensors and micro switches. Senior Aerospace Connecticut 4 Peerless Way, Enfield, 11/22/2013 The firm manufactures CT 99991. machined and assembled aerospace components. Western Electronics...

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.

Radical-pair based avian magnetoreception

NASA Astrophysics Data System (ADS)

Procopio, Maria; Ritz, Thorsten

2014-03-01

Behavioural experiments suggest that migratory birds possess a magnetic compass sensor able to detect the direction of the geomagnetic. One hypothesis for the basis of this remarkable sensory ability is that the coherent quantum spin dynamics of photoinduced radical pair reactions transduces directional magnetic information from the geomagnetic field into changes of reaction yields, possibly involving the photoreceptor cryptochrome in the birds retina. The suggested radical-pair based avian magnetoreception has attracted attention in the field of quantum biology as an example of a biological sensor which might exploit quantum coherences for its biological function. Investigations on such a spin-based sensor have focussed on uncovering the design features for the design of a biomimetic magnetic field sensor. We study the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

Genes and proteins involved in bacterial magnetic particle formation.

PubMed

Matsunaga, Tadashi; Okamura, Yoshiko

2003-11-01

Magnetic bacteria synthesize intracellular magnetosomes that impart a cellular swimming behaviour referred to as magnetotaxis. The magnetic structures aligned in chains are postulated to function as biological compass needles allowing the bacterium to migrate along redox gradients through the Earth's geomagnetic field lines. Despite the discovery of this unique group of microorganisms 28 years ago, the mechanisms of magnetic crystal biomineralization have yet to be fully elucidated. This review describes the current knowledge of the genes and proteins involved in magnetite formation in magnetic bacteria and the biotechnological applications of biomagnetites in the interdisciplinary fields of nanobiotechnology, medicine and environmental management.

Artifacts in the Wake: Leadership via an Oriented Compass Model

ERIC Educational Resources Information Center

Fallon, Paul D.

2013-01-01

Although inextricable, the act of leading, the leader, and outcome of leadership are unique entities. Lack of such differentiation may ensnare novice leaders in broad suppositions. This conceptual article introduces a tool for analyzing leadership. Leaders can leverage the model to evaluate the act of leading, in route, via a measurable trajectory…

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

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).

Loving-Kindness and Compassion Meditation: Potential for Psychological Interventions

PubMed Central

Hofmann, Stefan G.; Grossman, Paul; Hinton, Devon E.

2011-01-01

Mindfulness-based meditation interventions have become increasingly popular in contemporary psychology. Other closely related meditation practices include loving-kindness meditation (LKM) and compassion meditation (CM), exercises oriented toward enhancing unconditional, positive emotional states of kindness and compassion. This article provides a review of the background, the techniques, and the empirical contemporary literature of LKM and CM. The literature suggests that LKM and CM are associated with an increase in positive affect and a decrease in negative affect. Preliminary findings from neuroendocrine studies indicate that CM may reduce stress-induced subjective distress and immune response. Neuroimaging studies suggest that LKM and CM may enhance activation of brain areas that are involved in emotional processing and empathy. Finally, preliminary intervention studies support application of these strategies in clinical populations. It is concluded that, when combined with empirically supported treatments, such as cognitive behavioral therapy, LKM and CM may provide potentially useful strategies for targeting a variety of different psychological problems that involve interpersonal processes, such as social anxiety, marital conflict, anger, and coping with the strains of long-term caregiving. PMID:21840289

How could the Viking Sun compass be used with sunstones before and after sunset? Twilight board as a new interpretation of the Uunartoq artefact fragment

PubMed Central

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

2014-01-01

Vikings routinely crossed the North Atlantic without a magnetic compass and left their mark on lands as far away as Greenland, Newfoundland and Baffin Island. Based on an eleventh-century dial fragment artefact, found at Uunartoq in Greenland, it is widely accepted that they sailed along chosen latitudes using primitive Sun compasses. Such instruments were tested on sea and proved to be efficient hand-held navigation tools, but the dimensions and incisions of the Uunartoq find are far from optimal in this role. On the basis of the sagas mentioning sunstones, incompatible hypotheses were formed for Viking solar navigation procedures and primitive skylight polarimetry with dichroic or birefringent crystals. We describe here a previously unconceived method of navigation based on the Uunartoq artefact functioning as a ‘twilight board’, which is a combination of a horizon board and a Sun compass optimized for use when the Sun is close to the horizon. We deduced an appropriate solar navigation procedure using a twilight board, a shadow-stick and birefringent crystals, which bring together earlier suggested methods in harmony and provide a true skylight compass function. This could have allowed Vikings to navigate around the clock, to use the artefact dial as a Sun compass during long parts of the day and to use skylight polarization patterns in the twilight period. In field tests, we found that true north could be appointed with such a medieval skylight compass with an error of about ±4° when the artificially occluded Sun had elevation angles between +10° and −8° relative to the horizon. Our interpretation allows us to assign exact dates to the gnomonic lines on the artefact and outlines the schedule of the merchant ships that sustained the Viking colony in Greenland a millennium ago. PMID:24910520

How could the Viking Sun compass be used with sunstones before and after sunset? Twilight board as a new interpretation of the Uunartoq artefact fragment.

PubMed

Bernáth, Balázs; Farkas, Alexandra; Száz, Dénes; Blahó, Miklós; Egri, Adám; Barta, András; Akesson, Susanne; Horváth, Gábor

2014-06-08

Vikings routinely crossed the North Atlantic without a magnetic compass and left their mark on lands as far away as Greenland, Newfoundland and Baffin Island. Based on an eleventh-century dial fragment artefact, found at Uunartoq in Greenland, it is widely accepted that they sailed along chosen latitudes using primitive Sun compasses. Such instruments were tested on sea and proved to be efficient hand-held navigation tools, but the dimensions and incisions of the Uunartoq find are far from optimal in this role. On the basis of the sagas mentioning sunstones, incompatible hypotheses were formed for Viking solar navigation procedures and primitive skylight polarimetry with dichroic or birefringent crystals. We describe here a previously unconceived method of navigation based on the Uunartoq artefact functioning as a 'twilight board', which is a combination of a horizon board and a Sun compass optimized for use when the Sun is close to the horizon. We deduced an appropriate solar navigation procedure using a twilight board, a shadow-stick and birefringent crystals, which bring together earlier suggested methods in harmony and provide a true skylight compass function. This could have allowed Vikings to navigate around the clock, to use the artefact dial as a Sun compass during long parts of the day and to use skylight polarization patterns in the twilight period. In field tests, we found that true north could be appointed with such a medieval skylight compass with an error of about ±4° when the artificially occluded Sun had elevation angles between +10° and -8° relative to the horizon. Our interpretation allows us to assign exact dates to the gnomonic lines on the artefact and outlines the schedule of the merchant ships that sustained the Viking colony in Greenland a millennium ago.

The Combating Obesity in Māori and Pasifika Adolescent School-Children Study: COMPASS Methodology and Study Protocol

PubMed Central

Stoner, Lee; Shultz, Sarah P.; Lambrick, Danielle M.; Krebs, Jeremy; Weatherall, Mark; Palmer, Barry R.; Lane, Andrew M.; Kira, Geoff; Witter, Trevor; Williams, Michelle A.

2013-01-01

Background: Lifestyle modifications including, physical activity can reduce obesity-related morbidity and subsequent cardiovascular disease in youth. This study will investigate the efficacy of a culturally-sensitive, non-contact, boxing-orientated training program on obesity and related cardio-metabolic conditions in Māori and Pasifika adolescents. Details of the methodological aspects of recruitment, inclusion criteria, randomization, cultural sensitivity, intervention program, assessments, process evaluation, and statistical analyses are described. Methods: This study will be a community based, New Zealand, randomized control trial (RCT). Male and female obese (body mass index >95th percentile) Māori and Pasifika adolescents aged 14-16 years will be recruited and the sample size will be confirmed through a feasibility study. Combating Obesity in Māori and Pasifika Adolescent School-children Study (COMPASS) is a 6-month, theory-based program, conducted 3-times/week in a culturally appropriate setting. Each session includes 40 min boxing-orientated training and 30 min resistance training. Assessments will be made at baseline, 3-months, 6-months, 12-months, and 24-months. Main outcomes include abdominal obesity, endothelial function, and insulin resistance. Other outcomes include arterial stiffness, lipid profile, inflammatory biomarkers, well-being, and aerobic fitness. Control measures include physical activity, sleep behavior, and dietary intake. Results: As a protocol paper there are no specific results to present, our purpose is to share our RCT design with the scientific community. Conclusions: COMPASS will be used to provide direction for exercise prescription policy in at-risk Māori and Pasifika adolescents. PMID:23930168

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.

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…

Anatomical organization of the brain of a diurnal and a nocturnal dung beetle.

PubMed

Immonen, Esa-Ville; Dacke, Marie; Heinze, Stanley; El Jundi, Basil

2017-06-01

To avoid the fierce competition for food, South African ball-rolling dung beetles carve a piece of dung off a dung-pile, shape it into a ball and roll it away along a straight line path. For this unidirectional exit from the busy dung pile, at night and day, the beetles use a wide repertoire of celestial compass cues. This robust and relatively easily measurable orientation behavior has made ball-rolling dung beetles an attractive model organism for the study of the neuroethology behind insect orientation and sensory ecology. Although there is already some knowledge emerging concerning how celestial cues are processed in the dung beetle brain, little is known about its general neural layout. Mapping the neuropils of the dung beetle brain is thus a prerequisite to understand the neuronal network that underlies celestial compass orientation. Here, we describe and compare the brains of a day-active and a night-active dung beetle species based on immunostainings against synapsin and serotonin. We also provide 3D reconstructions for all brain areas and many of the fiber bundles in the brain of the day-active dung beetle. Comparison of neuropil structures between the two dung beetle species revealed differences that reflect adaptations to different light conditions. Altogether, our results provide a reference framework for future studies on the neuroethology of insects in general and dung beetles in particular. © 2017 Wiley Periodicals, Inc.

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...

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...

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.97 Section 61.97 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... using pilotage with the aid of a magnetic compass; (5) Recognition of critical weather situations from...

Acuity of a Cryptochrome and Vision-Based Magnetoreception System in Birds

PubMed Central

Solov'yov, Ilia A.; Mouritsen, Henrik; Schulten, Klaus

2010-01-01

Abstract The magnetic compass of birds is embedded in the visual system and it has been hypothesized that the primary sensory mechanism is based on a radical pair reaction. Previous models of magnetoreception have assumed that the radical pair-forming molecules are rigidly fixed in space, and this assumption has been a major objection to the suggested hypothesis. In this article, we investigate theoretically how much disorder is permitted for the radical pair-forming, protein-based magnetic compass in the eye to remain functional. Our study shows that only one rotational degree of freedom of the radical pair-forming protein needs to be partially constrained, while the other two rotational degrees of freedom do not impact the magnetoreceptive properties of the protein. The result implies that any membrane-associated protein is sufficiently restricted in its motion to function as a radical pair-based magnetoreceptor. We relate our theoretical findings to the cryptochromes, currently considered the likeliest candidate to furnish radical pair-based magnetoreception. PMID:20655831

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.

Physical Attraction: The Mysteries of Magnetism

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

Stohr, Joachim

2004-12-14

Most people have intuitive associations with the word 'magnetism' based on everyday life: refrigerator magnets, the compass, north and south poles, or someone's 'magnetic personality'. Few people, however, realize how complicated the phenomenon really is, how much research still deals with the topic today, and how much it penetrates our modern industrialized world - from electricity, wireless communication at the speed of light to magnetic sensors in cars and data storage in computers. Stohr's lecture will provide a glimpse at the magic and science behind magnetism: its long history, scientific breakthroughs in its understanding, and its use in our modernmore » society. In the process Stohr will show how research at SSRL/SLAC is addressing some of the forefront issues in magnetism research and technology today.« less

Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods

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

Imrisek, M.; Faculty of Mathematics and Physics, Charles University in Prague, Prague; Weinzettl, V.

2014-11-15

The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side.

Fitting of the Thomson scattering density and temperature profiles on the COMPASS tokamak

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

Stefanikova, E.; Division of Fusion Plasma Physics, KTH Royal Institute of Technology, SE-10691 Stockholm; Peterka, M.

2016-11-15

A new technique for fitting the full radial profiles of electron density and temperature obtained by the Thomson scattering diagnostic in H-mode discharges on the COMPASS tokamak is described. The technique combines the conventionally used modified hyperbolic tangent function for the edge transport barrier (pedestal) fitting and a modification of a Gaussian function for fitting the core plasma. Low number of parameters of this combined function and their straightforward interpretability and controllability provide a robust method for obtaining physically reasonable profile fits. Deconvolution with the diagnostic instrument function is applied on the profile fit, taking into account the dependence onmore » the actual magnetic configuration.« less

Magnetic monitoring of earth and space

USGS Publications Warehouse

Love, Jeffrey J.

2008-01-01

For centuries, navigators of the world’s oceans have been familiar with an effect of Earth’s magnetic field: It imparts a directional preference to the needle of a compass. Although in some settings magnetic orientation remains important, the modern science of geomagnetism has emerged from its romantic nautical origins and developed into a subject of great depth and diversity. The geomagnetic field is used to explore the dynamics of Earth’s interior and its surrounding space environment, and geomagnetic data are used for geophysical mapping, mineral exploration, risk mitigation, and other practical applications. A global distribution of ground-based magnetic observatories supports those pursuits by providing accurate records of the magnetic-field direction and intensity at fixed locations and over long periods of time.Magnetic observatories were first established in the early 19th century in response to the influence of Alexander von Humboldt and Carl Friedrich Gauss. Since then, magnetic measurement has advanced significantly, progressing from simple visual readings of magnetic survey instruments to include automatic photographic measurement and modern electronic acquisition. To satisfy the needs of the scientific community, observatories are being upgraded to collect data that meet ever more stringent standards, to achieve higher acquisition frequencies, and to disseminate data in real time.To appreciate why data from magnetic observatories can be used for so many purposes, one needs only to recall that the geomagnetic field is a continuum, connecting the different parts of Earth to each other and to nearby space. Beneath our feet and above our heads, electric currents generate magnetic fields that contribute to the totality of the geomagnetic field measured at an observatory on Earth’s surface. The many physical processes that operate in each geophysical domain give rise to a complicated field that exhibits a wide variety of time-dependent behavior.1 In this article I review the status of the global community of magnetic observatories, show how Earth and space can be monitored for purposes of scientific understanding and practical application, and highlight the role played by magnetic observatories in the history of geomagnetism research.

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...

Progress in diagnostics of the COMPASS tokamak

NASA Astrophysics Data System (ADS)

Weinzettl, V.; Adamek, J.; Berta, M.; Bilkova, P.; Bogar, O.; Bohm, P.; Cavalier, J.; Dejarnac, R.; Dimitrova, M.; Ficker, O.; Fridrich, D.; Grover, O.; Hacek, P.; Havlicek, J.; Havranek, A.; Horacek, J.; Hron, M.; Imrisek, M.; Komm, M.; Kovarik, K.; Krbec, J.; Markovic, T.; Matveeva, E.; Mitosinkova, K.; Mlynar, J.; Naydenkova, D.; Panek, R.; Paprok, R.; Peterka, M.; Podolnik, A.; Seidl, J.; Sos, M.; Stockel, J.; Tomes, M.; Varavin, M.; Varju, J.; Vlainic, M.; Vondracek, P.; Zajac, J.; Zacek, F.; Stano, M.; Anda, G.; Dunai, D.; Krizsanoczi, T.; Refy, D.; Zoletnik, S.; Silva, A.; Gomes, R.; Pereira, T.; Popov, Tsv.; Sarychev, D.; Ermak, G. P.; Zebrowski, J.; Jakubowski, M.; Rabinski, M.; Malinowski, K.; Nanobashvili, S.; Spolaore, M.; Vianello, N.; Gauthier, E.; Gunn, J. P.; Devitre, A.

2017-12-01

The COMPASS tokamak at IPP Prague is a small-size device with an ITER-relevant plasma geometry and operating in both the Ohmic as well as neutral beam assisted H-modes since 2012. A basic set of diagnostics installed at the beginning of the COMPASS operation has been gradually broadened in type of diagnostics, extended in number of detectors and collected channels and improved by an increased data acquisition speed. In recent years, a significant progress in diagnostic development has been motivated by the improved COMPASS plasma performance and broadening of its scientific programme (L-H transition and pedestal scaling studies, magnetic perturbations, runaway electron control and mitigation, plasma-surface interaction and corresponding heat fluxes, Alfvenic and edge localized mode observations, disruptions, etc.). In this contribution, we describe major upgrades of a broad spectrum of the COMPASS diagnostics and discuss their potential for physical studies. In particular, scrape-off layer plasma diagnostics will be represented by a new concept for microsecond electron temperature and heat flux measurements - we introduce a new set of divertor Langmuir and ball-pen probe arrays, newly constructed probe heads for reciprocating manipulators as well as several types of standalone probes. Among optical tools, an upgraded high-resolution edge Thomson scattering diagnostic for pedestal studies and a set of new visible light and infrared (plasma-surface interaction investigations) cameras will be described. Particle and beam diagnostics will be covered by a neutral particle analyzer, diagnostics on a lithium beam, Cherenkov detectors (for a direct detection of runaway electrons) and neutron detectors. We also present new modifications of the microwave reflectometer for fast edge density profile measurements.

Summoning compassion to address the challenges of conservation.

PubMed

Wallach, Arian D; Bekoff, Marc; Batavia, Chelsea; Nelson, Michael P; Ramp, Daniel

2018-04-27

Conservation practice is informed by science, but also reflects ethical beliefs about how we ought to value and interact with the Earth's biota. As human activities continue to drive extinctions and diminish critical life-sustaining ecosystem processes, achieving conservation goals becomes increasingly urgent. In our determination to react decisively, conservation challenges can be handled without due deliberation, particularly when wildlife individuals are sacrificed "for the greater good" of wildlife collectives (populations, species, ecosystems). With growing recognition of the widespread sentience and sapience of many nonhuman animals, standard conservation practices that categorically prioritize collectives without due consideration for the wellbeing of individuals are ethically untenable. Here we highlight three overarching ethical orientations characterizing current and historical practices in conservation that suppress compassion: instrumentalism, collectivism, and nativism. We illustrate how establishing a commitment to compassion could re-orient conservation in more ethically expansive directions, which incorporate recognition of the intrinsic value of wildlife, the sentience of nonhuman animals, and the values of novel ecosystems, introduced species and their members. A compassionate conservation approach allays practices that intentionally and unnecessarily harm wildlife individuals, while aligning with critical conservation goals. Although the urgency of achieving effective outcomes for solving major conservation problems may enhance the appeal of quick and harsh measures, the costs are too high. Continuing to justify moral indifference when causing the suffering of wildlife individuals, particularly those who possess sophisticated capacities for emotion, consciousness, and sociality, risks estranging conservation practice from prevailing, and appropriate, social values. As conservationists and compassionate beings, we must demonstrate concern for both the long-term persistence of collectives and the wellbeing of individuals, prioritizing strategies that do both. This article is protected by copyright. All rights reserved.

Quartermaster 1 and C, Rate Training Manual.

ERIC Educational Resources Information Center

Naval Personnel Program Support Activity, Washington, DC.

The technical subject matter of the Quartermaster rating is presented in this training manual written to prepare men of the Navy and Naval Reserve for advancement examinations. The manual includes eleven chapters. Discussed are commonly used methods and procedures of operating magnetic compasses and gyrocompasses, determining a ship's position,…

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...

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

How do honeybees use their magnetic compass? Can they see the North?

PubMed

Válková, T; Vácha, M

2012-08-01

While seeking food sources and routes back to their hive, bees make use of their advanced nervous and sensory capacities, which underlie a diverse behavioral repertoire. One of several honeybee senses that is both exceptional and intriguing is magnetoreception - the ability to perceive the omnipresent magnetic field (MF) of the Earth. The mechanism by which animals sense MFs has remained fascinating as well as elusive because of the intricacies involved, which makes it one of the grand challenges for neural and sensory biology. However, investigations in recent years have brought substantial progress to our understanding of how such magneto-receptor(s) may work. Some terrestrial animals (birds) are reported to be equipped even with a dual perception system: one based on diminutive magnetic particles - in line with the original model which has also always been hypothesized for bees - and the other one, as the more recent model describes, based on a sensitivity of some photochemical reactions to MF (radical-pair or chemical mechanism). The latter model postulates a close link to vision and supposes that the animals can see the position of the geomagnetic North as a visible pattern superimposed on the picture of the environment. In recent years, a growing body of evidence has shown that radical-pair magnetoreception might also be used by insects. It is realistic to expect that such evidence will inspire a re-examination and extension or confirmation of established views on the honeybee magnetic-compass mechanism. However, the problem of bee magnetoreception will not be solved at the moment that a receptor is discovered. On the contrary, the meaning of magnetoreception in insect life and its involvement in the orchestration of other senses is yet to be fully understood. The crucial question to be addressed in the near future is whether the compass abilities of the honeybee could suffer from radio frequency (RF) smog accompanying modern civilization and whether the fitness of this dominant pollinator might be affected by RF fields. The goal of this review is to provide an overview of the path that the behavioral research on honeybee magnetoreception has taken and to discuss it in the context of contemporary data obtained on other insects.

Electromagnetic characteristics of geodesic acoustic mode in the COMPASS tokamak

NASA Astrophysics Data System (ADS)

Seidl, J.; Krbec, J.; Hron, M.; Adamek, J.; Hidalgo, C.; Markovic, T.; Melnikov, A. V.; Stockel, J.; Weinzettl, V.; Aftanas, M.; Bilkova, P.; Bogar, O.; Bohm, P.; Eliseev, L. G.; Hacek, P.; Havlicek, J.; Horacek, J.; Imrisek, M.; Kovarik, K.; Mitosinkova, K.; Panek, R.; Tomes, M.; Vondracek, P.

2017-12-01

Axisymmetric geodesic acoustic mode (GAM) oscillations of the magnetic field, plasma potential and electron temperature have been identified on the COMPASS tokamak. This work brings an overview of their electromagnetic properties studied by multi-pin reciprocating probes and magnetic diagnostics. The n  =  0 fluctuations form a continuous spectrum in limited plasmas but change to a single dominant peak in diverted configuration. At the edge of diverted plasmas the mode exhibits a non-local structure with a constant frequency over a radial extent of at least several centimeters. Nevertheless, the frequency still reacts on temporal changes of plasma temperature caused by an auxiliary NBI heating as well as those induced by periodic sawtooth crashes. Radial wavelength of the mode is found to be about 1-4 cm, with values larger for the plasma potential than for the electron temperature. The mode propagates radially outward and its radial structure induces oscillations of a poloidal E  ×  B velocity, that can locally reach the level of the mean poloidal flow. Bicoherence analysis confirms a non-linear interaction of GAM with a broadband ambient turbulence. The mode exhibits strong axisymmetric magnetic oscillations that are studied both in the poloidal and radial components of the magnetic field. Their poloidal standing-wave structure was confirmed and described for the first time in diverted plasmas. In limited plasmas their amplitude scales with safety factor. Strong suppression of the magnetic GAM component, and possibly of GAM itself, is observed during co-current but not counter-current NBI.

Emerging adulthood and the perception of parental depression.

PubMed

Kaimal, Girija; Beardslee, William R

2010-09-01

Few studies have examined children's perceptions of parental depression. This study was a qualitative analysis of the changes in the perception of parental depression between the ages of 17 and 19 years. Archived interview narratives of 16 respondents from a longitudinal, preventive intervention study of depression in families were analyzed. The respondents were purposefully selected to represent both genders as well as higher and lower levels of family adversity. The perceptions of parental depression were found to fall into three categories: self-oriented perspectives (resistance and negativity), ambivalent perspectives, and, other-oriented perspectives (acceptance and compassion). Over time, respondents from the high-adversity families showed shifts from self-orientation to other-orientation, whereas the perspectives of respondents from low-adversity families remained unchanged. Some respondents with depression in both parents and/or siblings revealed changes in perception toward one parent but no change toward other family members with depression.

When the beachhopper looks at the moon: The moon compass hypothesis

NASA Technical Reports Server (NTRS)

Enright, J. T.

1972-01-01

The function of moon position for shoreline orientation by talitrids is investigated. Three major results were found: (1) Observed cases of compensation for changes in the direction of the moon are based on physiological rhythm with a period of about 25 hours which can persist for at least several days under constant conditions. (2) The zeitgeber for physiological rhythm may be either moonlight or some other factor associated with the tides. (3) If talitrids are long removed from environmental entrainment, either artifically or naturally, the internal rhythm no longer exerts an appreciable influence on the angle of lunar orientation; in such cases the system deteriorates into constant angle orientation, with an angle which is determined by the beach orgin, but may be modified by lighting conditions.

Recent Development of an Earth Science App - FieldMove Clino

NASA Astrophysics Data System (ADS)

Vaughan, Alan; Collins, Nathan; Krus, Mike; Rourke, Peter

2014-05-01

As geological modelling and analysis move into 3D digital space, it becomes increasingly important to be able to rapidly integrate new data with existing databases, without the potential degradation caused by repeated manual transcription of numeric, graphical and meta-data. Digital field mapping offers significant benefits when compared with traditional paper mapping techniques, in that it can directly and interactively feed and be guided by downstream geological modelling and analysis. One of the most important pieces of equipment used by the field geologists is the compass clinometer. Midland Valley's development team have recently release their highly anticipated FieldMove Clino App. FieldMove Clino is a digital compass-clinometer for data capture on a smartphone. The app allows the user to use their phone as a traditional hand-held bearing compass, as well as a digital compass-clinometer for rapidly measuring and capturing the georeferenced location and orientation of planar and linear features in the field. The user can also capture and store digital photographs and text notes. FieldMove Clino supports online Google Maps as well as offline maps, so that the user can import their own georeferenced basemaps. Data can be exported as comma-separated values (.csv) or Move™ (.mve) files and then imported directly into FieldMove™, Move™ or other applications. Midland Valley is currently pioneering tablet-based mapping and, along with its industrial and academic partners, will be using the application in field based projects throughout this year and will be integrating feedback in further developments of this technology.

Seismic Motion Stability, Measurement and Precision Control.

DTIC Science & Technology

1979-12-01

tiltmeter . Tilt was corrected by changing air pressure in one bank of isolators to maintain the reference tiltmeter at null well within the 0.1 arcsecond...frequency rotations (0-0.1 Hz), a high quality, two-axis tiltmeter is used. The azimuth orientation angle could be measured with a four-position gyro...compassing system with considerably less accuracy than the tiltmeters . However, it would provide a continuous automatic azimuth determination update every

Planetary rover robotics experiment in education: carbonate rock collecting experiment of the Husar-5 rover

NASA Astrophysics Data System (ADS)

Szalay, Kristóf; Lang, Ágota; Horváth, Tamás; Prajczer, Péter; Bérczi, Szaniszló

2013-04-01

Introduction: The new experiment for the Husar-5 educational space probe rover consists of steps of the technology of procedure of finding carbonate speci-mens among the rocks on the field. 3 main steps were robotized: 1) identification of carbonate by acid test, 2) measuring the gases liberated by acid, and 3) magnetic test. Construction of the experiment: The basis of the robotic realization of the experiment is a romote-controlled rover which can move on the field. Onto this rover the mechanism of the experiments were built from Technics LEGO elements and we used LEGO-motors for making move these experiments. The operation was coordinated by an NXT-brick which was suitable to programming. Fort he acetic-test the drops should be passed to the selected area. Passing a drop to a locality: From the small holder of the acid using densified gas we pump some drop onto the selected rock. We promote this process by pumpig the atmospheric gas into another small gas-container, so we have another higher pressure gas there. This is pumped into the acid-holder. The effect of the reaction is observed by a wireless onboard camera In the next step we can identify the the liberated gas by the gas sensor. Using it we can confirm the liberation of the CO2 gas without outer observer. The third step is the controll of the paramagnetic properties.. In measuring this feature a LEGO-compass is our instrumentation. We use a electric current gener-ated magnet. During the measurements both the coil and the gas-sensor should be positioned to be near to the surface. This means, that a lowering and an uplifting machinery should be constructed. Summary: The sequence of the measurement is the following. 1) the camera - after giving panorama images - turns toward the soil surface, 2) the dropping onto the rock surface 3) at the same time the gas-sensor starts to move down above the rock 4) the compass sensor also moves down on the arm which holds both the gas-sensor and the compass-sensor 5) evaluation of the gas-sensor data 6) if CO2 is present the magnet-test begins, therefore the rovers moves forward into a good position for the coil lowering 7) after magnetization the rover moves backward in order to be in the position that the compass-sesnsor can measure the angle. 8) the last 2 operations are repeated in a small turned position of the rover 9) final calculation of the paramagnetic measurement 10) summary of the 3 tests

Orientation behaviour of leatherback sea turtles within the North Atlantic subtropical gyre

PubMed Central

Dodge, Kara L.; Galuardi, Benjamin; Lutcavage, Molly E.

2015-01-01

Leatherback sea turtles (Dermochelys coriacea) travel thousands of kilometres between temperate feeding and tropical breeding/over-wintering grounds, with adult turtles able to pinpoint specific nesting beaches after multi-year absences. Their extensive migrations often occur in oceanic habitat where limited known sensory information is available to aid in orientation. Here, we examined the migratory orientation of adult male, adult female and subadult leatherbacks during their open-ocean movements within the North Atlantic subtropical gyre by analysing satellite-derived tracks from fifteen individuals over a 2-year period. To determine the turtles' true headings, we corrected the reconstructed tracks for current drift and found negligible differences between current-corrected and observed tracks within the gyre. Individual leatherback headings were remarkably consistent throughout the subtropical gyre, with turtles significantly oriented to the south-southeast. Adult leatherbacks of both sexes maintained similar mean headings and showed greater orientation precision overall. The consistent headings maintained by adult and subadult leatherbacks within the gyre suggest use of a common compass sense. PMID:25761714

Deflection of the Interstellar Neutral Hydrogen Flow Across the Heliospheric Interface: an Interstellar Magnetic Compass

NASA Astrophysics Data System (ADS)

Lallement, R.; Eric, Q.; Jean-Loup, B.; Dimitra, K.; Risto, P.

2005-05-01

Analyses of SOHO-SWAN observations show that the interstellar neutral H flow direction differs by about 4 degrees from the neutral He flow direction recently derived with an unprecedented accuracy using combined data sets (Mobius et al, 2004). The most likely explanation is a distortion of the heliospheric interface under the action of an inclined interstellar magnetic field, with imprints of the distorsion on the neutral H flow due to charge-transfer reactions between H atoms and ions. The direction of the ambient interstellar magnetic field and the heliospheric shape can be derived from the observed deviation. Implications for Voyager trajectories are discussed.

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.

Environmental Data Collection Using Autonomous Wave Gliders

DTIC Science & Technology

2014-12-01

Observing System IMU Inertial Measurement Unit LRI Liquid Robotics, Inc. MASFlux Marine-Air-Sea-Flux METOC meteorological and oceanographic...position, velocity, heading, pitch, roll , and six-axis acceleration rates (Figure 11). A separate temperature probe also provides sea surface...Position, Velocity, and Magnetic declination True North Revolution Technologies GS Gyro Stabilized Electronic Compass Heading, Pitch, and Roll

The COMPASS Tokamak Plasma Control Software Performance

NASA Astrophysics Data System (ADS)

Valcarcel, Daniel F.; Neto, André; Carvalho, Ivo S.; Carvalho, Bernardo B.; Fernandes, Horácio; Sousa, Jorge; Janky, Filip; Havlicek, Josef; Beno, Radek; Horacek, Jan; Hron, Martin; Panek, Radomir

2011-08-01

The COMPASS tokamak has began operation at the IPP Prague in December 2008. A new control system has been built using an ATCA-based real-time system developed at IST Lisbon. The control software is implemented on top of the MARTe real-time framework attaining control cycles as short as 50 μs, with a jitter of less than 1 μs. The controlled parameters, important for the plasma performance, are the plasma current, position of the plasma current center, boundary shape and horizontal and vertical velocities. These are divided in two control cycles: slow at 500 μs and fast at 50 μs. The project has two phases. First, the software implements a digital controller, similar to the analog one used during the COMPASS-D operation in Culham. In the slow cycle, the plasma current and position are measured and controlled with PID and feedforward controllers, respectively, the shaping magnetic field is preprogrammed. The vertical instability and horizontal equilibrium are controlled with the faster 50-μs cycle PID controllers. The second phase will implement a plasma-shape reconstruction algorithm and controller, aiming at optimized plasma performance. The system was designed to be as modular as possible by breaking the functional requirements of the control system into several independent and specialized modules. This splitting enabled tuning the execution of each system part and to use the modules in a variety of applications with different time constraints. This paper presents the design and overall performance of the COMPASS control software.

Freely oriented portable superconducting magnet

DOEpatents

Schmierer, Eric N [Los Alamos, NM; Prenger, F Coyne [Los Alamos, NM; Hill, Dallas D [Los Alamos, NM

2010-01-12

A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

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.

Geomagnetic Investigation of Sandstone Dikes of the Colorado Front Range, for Determination of Age and Mode of Emplacement

NASA Astrophysics Data System (ADS)

Freedman, D.; Petronis, M. S.; Siddoway, C. S.

2012-12-01

In the Colorado Front Range, an array of sandstone dikes has intrigued geologists for over a century (Cross 1894,GSAB, 5, 525). Within their crystalline host, the dikes reach widths >7m and have a lateral extent of 70km along the Ute Pass Fault (UPF). The essential questions of sediment source, emplacement mode, and age of the dikes are unanswered. We present new paleomagnetic, rock magnetic, and anisotropy of magnetic susceptibility (AMS) results used to determine the age and emplacement behavior of the dikes. The eleven dikes selected for magnetic studies have sharp, planar margins, and share the systematic geometry of the NW striking subvertical dike array. They exhibit little or no overprint by brittle fracturing/shear associated with the UPF. Our approach involved the use of paleomagnetic techniques to isolate the characteristic remanent magnetization (ChRM), which we used to limit the age of the dikes' magnetization. Anisotropy of magnetic susceptibility (AMS),arising from alignment of detrital magnetite, serves as a proxy for the orientation of flow during dike emplacement. U-Pb detrital zircon ages, obtained previously, did not provide a useful constraint on emplacement age because the dominant age matches that of the prevalent host,1.03Ga Pikes Peak Granite. IRM acquisition experiments were performed to identify the principal magnetic phases as a mixture of Fe-Ti oxide phases, likely to be low-Ti magnetite and hematite. The sandstone consists of sub-rounded to rounded sand-sized quartz, angular feldspar (<5%), and detrital magnetite; selected samples have uniform grain size and uniform color arising from hematite cement. Although direct cover relationships are not preserved, a portion of the study sites are proximal to in situ near-horizontal sedimentary cover rocks that offer evidence against large tectonic rotation. Cores were collected using a gas-powered drill with a diamond bit and oriented using a sun compass. Where possible, cores were obtained on paired margins to test for directionality of flow using AMS. Paleomagnetic results reveal a magnetization carried by both magnetite and hematite. Laboratory unblocking temperatures for most samples are >600°C. Some samples carry a characteristic remanent magnetization (ChRM) of NW declination with shallow positive inclination, while others yield a characteristic remanent magnetization of SE declination with shallow inclination. By correlation with paleomagnetic results from the region, our findings indicate an age Permian or older. The NW directed ChRM may signify a magnetization of Neoproterozoic age, while the SE directed ChRM is more consistent with a Permo-Carboniferous magnetization. Our investigation of these possibilities is ongoing. Analysis of AMS for nine dike sites yielded subhorizontal strongly prolate magnetic ellipsoids. The magnetic lineation (K1) has moderate plunge and trends NW, parallel to the dike margins. Average bulk susceptibilities (Km) are low (6.39E-5 SI). The AMS characteristics, together with primary sedimentary structures point to instantaneous lateral injection due to elevated pore fluid pressures arising from high lithostatic or tectonic loads. We hypothesize that sediment production and fluid overpressure led to emplacement in a glacial or seismically active setting.

Scaling Up the Pulse-Remagnetization Experiment for Large Animals

NASA Astrophysics Data System (ADS)

Kirschvink, J. L.; Hilburn, I. A.; Golash, H. N.; Wang, C. X.; Wu, D. A.; Mizuhara, Y.; Shimojo, S.; Matani, A.

2016-12-01

Pulse-remagnetization has been a commonly-used technique in rock magnetic studies for producing IRM curves for the past 33 years. Typical circuits involve charging a bank of capacitors to a desired voltage, and then discharging it on command through a silicon-controlled rectifier into a solenoid magnet coil. Back-oscillations are prevented by dissipating the energy with a suitably-configured diode, and the intensity of the single magnetic peak resulting from this procedure is proportional to the charging voltage. However, this technique also has been applied many times in biology to measure the coercivity spectrum of various populations of magnetoctactic bacteria, as well as in successful tests of the hypothesis that biological magnetite is the biophysical transducer for magnetic field sensitivity (magnetoreception) in animals. We have recently discovered earth-strength magnetic effects on the brainwave patterns of a large mammal. Experimental results indicate that the effects are not a result of either electrical induction or an axially-symmetric biophysical compass; therefore, the most likely explanation is a polar compass provided by specialized sensory cells containing chains of single-domain biological magnetite. If so, we should be able to invert the magnetic polarity of this response via a properly-configured pulse-remagnetization experiment, and thereby place constraints on the microscopic coercivity of the magnetite crystals in the hypothesized receptor cells. To achieve this end, we have constructed a large-volume IRM coil capable of producing a uniform magnetic field pulse of up to 70 mT over the volume of the target animal's head, while also applying a co-axial 1 mT static DC biasing field. Applying a DC-biased IRM pulse to our animal subjects has proven to be surprisingly difficult, both due to the complexity of engineering a coaxial pulse and biasing coil system of this volume, and also due to the care and safety protocols necessary to ensure the well-being of our subjects.

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.

A sky polarization compass in lizards: the central role of the parietal eye.

PubMed

Beltrami, G; Bertolucci, C; Parretta, A; Petrucci, F; Foà, A

2010-06-15

The present study first examined whether ruin lizards Podarcis sicula are able to orientate using the e-vector direction of polarized light. Ruin lizards were trained and tested indoors, inside a hexagonal Morris water maze, positioned under an artificial light source producing plane polarized light with a single e-vector, which provided an axial cue. Lizards were subjected to axial training by positioning two identical goals in contact with the centre of two opposite side walls of the Morris water maze. Goals were invisible because they were placed just beneath the water surface, and water was rendered opaque. The results showed that the directional choices of lizards meeting learning criteria were bimodally distributed along the training axis, and that after 90 deg rotation of the e-vector direction of polarized light the lizards directional choices rotated correspondingly, producing a bimodal distribution which was perpendicular to the training axis. The present results confirm in ruin lizards results previously obtained in other lizard species showing that these reptiles can use the e-vector direction of polarized light in the form of a sky polarization compass. The second step of the study aimed at answering the still open question of whether functioning of a sky polarization compass would be mediated by the lizard parietal eye. To test this, ruin lizards meeting learning criteria were tested inside the Morris water maze under polarized light after their parietal eyes were painted black. Lizards with black-painted parietal eyes were completely disoriented. Thus, the present data show for the first time that the parietal eye plays a central role in mediating the functioning of a putative sky polarization compass of lizards.

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.

Observations on the method of determining the velocity of airships

NASA Technical Reports Server (NTRS)

Volterra, Vito

1921-01-01

To obtain the absolute velocity of an airship by knowing the speed at which two routes are covered, we have only to determine the geographical direction of the routes which we locate from a map, and the angles of routes as given by the compass, after correcting for the variation (the algebraical sum of the local magnetic declination and the deviation).

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

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...

Hans Christian Ørsted, Narratives, Oeuvres and Physics Education

ERIC Educational Resources Information Center

Michelsen, Claus

2017-01-01

In 1820 the Danish scientist Hans Christian Ørsted discovered the relationship between electricity and magnetism by his famous wire-compass experiment. Ørsted was one of the foremost scientists of the nineteenth century, and he was also one of the leading figures in Denmark in the 19th century with a vital influence in the fields of aesthetics,…

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.

High resolution t-LiDAR scanning of an active bedrock fault scarp for palaeostress analysis

NASA Astrophysics Data System (ADS)

Reicherter, Klaus; Wiatr, Thomas; Papanikolaou, Ioannis; Fernández-Steeger, Tomas

2013-04-01

Palaeostress analysis of an active bedrock normal fault scarp based on kinematic indicators is carried applying terrestrial laser scanning (t-LiDAR or TLS). For this purpose three key elements are necessary for a defined region on the fault plane: (i) the orientation of the fault plane, (ii) the orientation of the slickenside lineation or other kinematic indicators and (iii) the sense of motion of the hanging wall. We present a workflow to obtain palaeostress data from point cloud data using terrestrial laser scanning. The entire case-study was performed on a continuous limestone bedrock normal fault scarp on the island of Crete, Greece, at four different locations along the WNW-ESE striking Spili fault. At each location we collected data with a mobile terrestrial light detection and ranging system and validated the calculated three-dimensional palaeostress results by comparison with the conventional palaeostress method with compass at three of the locations. Numerous kinematics indicators for normal faulting were discovered on the fault plane surface using t-LiDAR data and traditional methods, like Riedel shears, extensional break-outs, polished corrugations and many more. However, the kinematic indicators are more or less unidirectional and almost pure dip-slip. No oblique reactivations have been observed. But, towards the tips of the fault, inclination of the striation tends to point towards the centre of the fault. When comparing all reconstructed palaeostress data obtained from t-LiDAR to that obtained through manual compass measurements, the degree of fault plane orientation divergence is around ±005/03 for dip direction and dip. The degree of slickenside lineation variation is around ±003/03 for dip direction and dip. Therefore, the percentage threshold error of the individual vector angle at the different investigation site is lower than 3 % for the dip direction and dip for planes, and lower than 6 % for strike. The maximum mean variation of the complete calculated palaeostress tensors is ±005/03. So, technically t-LiDAR measurements are in the error range of conventional compass measurements. The advantages is that remote palaeostress analysis is possible. Further steps in our research will be studying reactivated faults planes with multiple kinematic indicators or striations with t-LiDAR.

Millitesla magnetic field effects on the photocycle of an animal cryptochrome

NASA Astrophysics Data System (ADS)

Sheppard, Dean M. W.; Li, Jing; Henbest, Kevin B.; Neil, Simon R. T.; Maeda, Kiminori; Storey, Jonathan; Schleicher, Erik; Biskup, Till; Rodriguez, Ryan; Weber, Stefan; Hore, P. J.; Timmel, Christiane R.; MacKenzie, Stuart R.

2017-02-01

Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and the possibility that weak, low-frequency anthropogenic electromagnetic fields may have biological consequences. In both cases, the presumed receptor is cryptochrome, a protein thought to be responsible for magnetic compass sensing in migratory birds and a variety of magnetic behavioural responses in insects. Here, we demonstrate that photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome are indeed influenced by magnetic fields of a few millitesla. The form of the protein containing flavin and tryptophan radicals shows kinetics that differ markedly from those of closely related members of the cryptochrome-photolyase family. These differences and the magnetic sensitivity of Drosophila cryptochrome are interpreted in terms of the radical pair mechanism and a photocycle involving the recently discovered fourth tryptophan electron donor.

Electromagnetic Induction with Neodymium Magnets

NASA Astrophysics Data System (ADS)

Wood, Deborah; Sebranek, John

2013-09-01

In April 1820, Hans Christian Ørsted noticed that the needle of a nearby compass deflected briefly from magnetic north each time the electric current of the battery he was using for an unrelated experiment was turned on or off. Upon further investigation, he showed that an electric current flowing through a wire produces a magnetic field. In 1831 Michael Faraday and Joseph Henry separately expanded on Ørsted's discovery by showing that a changing magnetic field produces an electric current. Heinrich Lenz found in 1833 that an induced current has the opposite direction from the electromagnetic force that produced it. This paper describes an experiment that can help students to develop an understanding of Faraday's law and Lenz's law by studying the emf generated as a magnet drops through a set of coils having increasing numbers of turns.

Detection of alterations in human sperm using magnetic orientation techniques

NASA Astrophysics Data System (ADS)

Sakhnini, Lama; Dairi, Maheen; Manaa, Hacene

2007-09-01

In this study we report on magnetic orientation of human sperms. Samples were taken from 17 donors. Normal human sperms became oriented with their long axis perpendicular to the magnetic field ( 1 Tesla maximum). Total orientation was achieved with magnetic field at about one Tesla, while for abnormal sperms the magnetic behavior was different. The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result for a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of normal sperm was found to be ▵ χ= 8×10 -20 J/T2. The degree of orientation was influenced by the alterations in the shape of the head, body or the tail. It has been suggested that the DNA in the sperm head retain the strong magnetic anisotropy to counter balance the magnetic anisotropy retained by flagellum microtubules. Recent studies demonstrated a well-defined nuclear architecture in human sperm nucleus, where the head morphology has significant correlation with sperm chromatin structure assay SCSA. Then as the methods to evaluate SCSA can be difficult and expensive our simple magnetic orientation technique can be an alternative to diagnose alteration in DNA.

[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.

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.

Training Requirements and Job Language Performance Requirements for MOS 11B, Infantryman.

DTIC Science & Technology

1982-10-01

I-.* - : Combat Tech : Ma recding Orient a map using a compass apparent rotate alternate refer.nce ability angle shown suitable block to the ground...one through ee:.. These appcndices co.-taiii the formr for’ the information gathcrinig. They also contain all, the information used to deternine the .b...Apendix two is the Task Inventory/Compiled Data Form. it was used to record the point values of the variables nceded in the task prioritizitior, proccss

A Drift Chamber to Measure Charged Particles at COMPASS-II

NASA Astrophysics Data System (ADS)

Heitz, Robert; Compass Collaboration

2013-10-01

A new drift chamber (DC05) will be constructed to replace two tracking detector stations based on straw tubes, ST02 and ST03 in the COMPASS spectrometer. DC05 uses the designs from DC04, a previous drift chamber designed at CEA-Saclay, France, but adds the addition of more wires for improved acceptance. In addition to more wires DC05 will also change its front end electronics using a new pre-amplifier-discriminator chip (CMAD). DC05 consists of 8 layers of anode planes and 21 layers of G-10 material frames carrying cathode planes and gas windows. The wires are orientated with two layers in the vertical x-direction, two layers in the horizontal y-direction, two layers offset +10 deg of the vertical x-direction, and two layers offset -10 deg of the vertical x-direction. The wires in parallel directions are offset half a pitch to resolve left-right ambiguities. The purpose for different wire orientations is to reconstruct the 3D space particle trajectory to fit a particle track. Each layer of wires is covered on the top and bottom by a cathode plane of carbon coated mylar. All these layers are sandwiched between two steel stiffening frames for support and noise reduction. A future drift chamber, DC06, is also being designed based off of DC05. Research funded by NSF-PHY-12-05-671 Medium Energy Nuclear Physics.

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

Multi-sensor Array for High Altitude Balloon Missions to the Stratosphere

NASA Astrophysics Data System (ADS)

Davis, Tim; McClurg, Bryce; Sohl, John

2008-10-01

We have designed and built a microprocessor controlled and expandable multi-sensor array for data collection on near space missions. Weber State University has started a high altitude research balloon program called HARBOR. This array has been designed to data log a base set of measurements for every flight and has room for six guest instruments. The base measurements are absolute pressure, on-board temperature, 3-axis accelerometer for attitude measurement, and 2-axis compensated magnetic compass. The system also contains a real time clock and circuitry for logging data directly to a USB memory stick. In typical operation the measurements will be cycled through in sequence and saved to the memory stick along with the clock's time stamp. The microprocessor can be reprogrammed to adapt to guest experiments with either analog or digital interfacing. This system will fly with every mission and will provide backup data collection for other instrumentation for which the primary task is measuring atmospheric pressure and temperature. The attitude data will be used to determine the orientation of the onboard camera systems to aid in identifying features in the images. This will make these images easier to use for any future GIS (geographic information system) remote sensing missions.

TUTORIAL: Beyond sensory substitution—learning the sixth sense

NASA Astrophysics Data System (ADS)

Nagel, Saskia K.; Carl, Christine; Kringe, Tobias; Märtin, Robert; König, Peter

2005-12-01

Rapid advances in neuroscience have sparked numerous efforts to study the neural correlate of consciousness. Prominent subjects include higher sensory area, distributed assemblies bound by synchronization of neuronal activity and neurons in specific cortical laminae. In contrast, it has been suggested that the quality of sensory awareness is determined by systematic change of afferent signals resulting from behaviour and knowledge thereof. Support for such skill-based theories of perception is provided by experiments on sensory substitution. Here, we pursue this line of thought and create new sensorimotor contingencies and, hence, a new quality of perception. Adult subjects received orientation information, obtained by a magnetic compass, via vibrotactile stimulation around the waist. After six weeks of training we evaluated integration of the new input by a battery of tests. The results indicate that the sensory information provided by the belt (1) is processed and boosts performance, (2) if inconsistent with other sensory signals leads to variable performance, (3) does interact with the vestibular nystagmus and (4) in half of the experimental subjects leads to qualitative changes of sensory experience. These data support the hypothesis that new sensorimotor contingencies can be learned and integrated into behaviour and affect perceptual experience.

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.

Effects of orientation on the time decay of magnetization for cobalt-alloy thin film media

NASA Astrophysics Data System (ADS)

Wang, J. P.; Alex, Michael; Tan, L. P.; Yan, M. L.

1999-04-01

The dependence of the time decay of magnetization on orientation ratio was investigated for longitudinal Co-alloy thin film media. The coercivity orientation ratio was controlled by the degree of mechanical texture. For oriented samples, it was found that the remanent magnetization along the circumferential direction decayed faster with time than that along the radial direction when the applied reverse magnetic field was near the remanent coercivity. However, the remanent magnetization along the circumferential direction decayed more slowly with time than that along the radial direction when the applied reverse magnetic field was less than roughly half the remanent coercivity. Anisotropic interactions and magnetic anisotropy distributions appear to be the cause for the different time decay of magnetization along the circumferential and radial directions for oriented media.

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.

Magnetic orientation in C. elegans relies on the integrity of the villi of the AFD magnetosensory neurons.

PubMed

Bainbridge, Chance; Rodriguez, Anjelica; Schuler, Andrew; Cisneros, Michael; Vidal-Gadea, Andrés G

2016-10-01

The magnetic field of the earth provides many organisms with sufficient information to successfully navigate through their environments. While evidence suggests the widespread use of this sensory modality across many taxa, it remains an understudied sensory modality. We have recently showed that the nematode C. elegans orients to earth-strength magnetic fields using the first pair of described magnetosensory neurons, AFDs. The AFD cells are a pair of ciliated sensory neurons crowned by fifty villi known to be implicated in temperature sensation. We investigated the potential importance of these subcellular structures for the performance of magnetic orientation. We show that ciliary integrity and villi number are essential for magnetic orientation. Mutants with impairments AFD cilia or villi structure failed to orient to magnetic fields. Similarly, C. elegans larvae possessing immature AFD neurons with fewer villi were also unable to orient to magnetic fields. Larvae of every stage however retained the ability to orient to thermal gradients. To our knowledge, this is the first behavioral separation of magnetic and thermal orientation in C. elegans. We conclude that magnetic orientation relies on the function of both cilia and villi in the AFD neurons. The role of villi in multiple sensory transduction pathways involved in the sensory transduction of vectorial stimuli further supports the likely role of the villi of the AFD neurons as the site for magnetic field transduction. The genetic and behavioral tractability of C. elegans make it a promising system for uncovering potentially conserved molecular mechanisms by which animals across taxa detect and orient to magnetic fields. 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.

The navigation of homing pigeons: Do they use sun Navigation?

NASA Technical Reports Server (NTRS)

Walcott, C.

1972-01-01

Experiments to determine the dependence of homing pigeons on the sun as a navigational cue are discussed. Various methods were employed to interrupt the circadian rhythms of the pigeons prior to release. It was determined that the sun may serve as a compass, but that topographic features are more important for navigation. The effects of a magnetic field produced by electric equipment carried by the bird were also investigated. It was concluded that magnetic fields may have a small effect on the homing ability. The exact nature of the homing pigeon's navigational ability is still unknown after years of elaborate experimentation.

X-ray compass for determining device orientation

DOEpatents

Da Silva, Luiz B.; Matthews, Dennis L.; Fitch, Joseph P.; Everett, Matthew J.; Colston, Billy W.; Stone, Gary F.

1999-01-01

An apparatus and method for determining the orientation of a device with respect to an x-ray source. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source.

X-ray compass for determining device orientation

DOEpatents

Da Silva, L.B.; Matthews, D.L.; Fitch, J.P.; Everett, M.J.; Colston, B.W.; Stone, G.F.

1999-06-15

An apparatus and method for determining the orientation of a device with respect to an x-ray source are disclosed. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source. 25 figs.

Orientation behaviour of leatherback sea turtles within the North Atlantic subtropical gyre.

PubMed

Dodge, Kara L; Galuardi, Benjamin; Lutcavage, Molly E

2015-04-07

Leatherback sea turtles (Dermochelys coriacea) travel thousands of kilometres between temperate feeding and tropical breeding/over-wintering grounds, with adult turtles able to pinpoint specific nesting beaches after multi-year absences. Their extensive migrations often occur in oceanic habitat where limited known sensory information is available to aid in orientation. Here, we examined the migratory orientation of adult male, adult female and subadult leatherbacks during their open-ocean movements within the North Atlantic subtropical gyre by analysing satellite-derived tracks from fifteen individuals over a 2-year period. To determine the turtles' true headings, we corrected the reconstructed tracks for current drift and found negligible differences between current-corrected and observed tracks within the gyre. Individual leatherback headings were remarkably consistent throughout the subtropical gyre, with turtles significantly oriented to the south-southeast. Adult leatherbacks of both sexes maintained similar mean headings and showed greater orientation precision overall. The consistent headings maintained by adult and subadult leatherbacks within the gyre suggest use of a common compass sense. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Magnetism: Principles and Applications

NASA Astrophysics Data System (ADS)

Craik, Derek J.

2003-09-01

If you are studying physics, chemistry, materials science, electrical engineering, information technology or medicine, then you'll know that understanding magnetism is fundamental to success in your studies and here is the key to unlocking the mysteries of magnetism....... You can: obtain a simple overview of magnetism, including the roles of B and H, resonances and special techniques take full advantage of modern magnets with a wealth of expressions for fields and forces develop realistic general design programmes using isoparametric finite elements study the subtleties of the general theory of magnetic moments and their dynamics follow the development of outstanding materials appreciate how magnetism encompasses topics as diverse as rock magnetism, chemical reaction rates, biological compasses, medical therapies, superconductivity and levitation understand the basis and remarkable achievements of magnetic resonance imaging In his new book, Magnetism, Derek Craik throws light on the principles and applications of this fascinating subject. From formulae for calculating fields to quantum theory, the secrets of magnetism are exposed, ensuring that whether you are a chemist or engineer, physicist, medic or materials scientist Magnetism is the book for our course.

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.

Pedagogy of stereographic projection

NASA Astrophysics Data System (ADS)

Blenkinsop, Tom

1999-05-01

Three sorts of problem are encountered by students learning stereographic projection. Lack of familiarity with compass directions and with the specification of planar and linear orientations is the most fundamental problem. The second problem is one of poor visualisation which prohibits the correct understanding of the principles and practice of projection, although students can sometimes perform remarkably well on certain exercises without this understanding. A third problem is a lack of interest or appreciation of the usefulness of the technique. A solution to the first problem is to provide a thorough grounding in compass directions, and concepts of strike, dip, dip direction, plunge and plunge bearing immediately before teaching stereographic projection. Visual aids, such as a transparent hemisphere to represent half of the projection sphere, and a large stereonet, are helpful for visualisation. Estimation and sketching exercises help to develop an understanding of the geometry of projection. Computer-aided teaching and plotting is recommended after an introduction to manual techniques. Interest can be stimulated through the use of exercises based on real geological maps.

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.

Sexual-Orientation Differences in Positive Youth Development: The Mediational Role of Bullying Victimization.

PubMed

Coulter, Robert W S; Herrick, A L; Friedman, M Reuel; Stall, Ron D

2016-04-01

To examine sexual-orientation differences in positive youth development, and how bullying victimization mediated these differences in a sample of adolescents. In 2007 to 2008, positive youth development was measured in 1870 adolescents from US schools and after-school programs in 45 states by using the validated Five Cs model of competence, confidence, connection, character, and caring/compassion. Sexual-minority youths (6.8%) reported having same- or both-gender sexual attractions. Nonattracted youths (4.2%) reported having no sexual attractions. Compared with sexual-minority youths, heterosexual and nonattracted youths had lower odds of being a victim of bullying. Heterosexual and nonattracted youths also had higher average scores in competence, confidence, and connection, but these associations between sexual orientation and positive youth development scores were partly attributable to lack of bullying victimization. Designing, implementing, and evaluating interventions that reduce bullying can give sexual-minority youths access to several building blocks of health and well-being.

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.

Orientation Control of Interfacial Magnetism at La 0.67Sr 0.33MnO 3/SrTiO 3 Interfaces

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

Guo, Er-Jia; Charlton, Timothy; Ambaye, Haile

Understanding the magnetism at the interface between a ferromagnet and an insulator is essential because the commonly posited magnetic “dead” layer close to an interface can be problematic in magnetic tunnel junctions. Previously, degradation of the magnetic interface was attributed to charge discontinuity across the interface. In this paper, the interfacial magnetism was investigated using three identically prepared La 0.67Sr 0.33MnO 3 (LSMO) thin films grown on different oriented SrTiO 3 (STO) substrates by polarized neutron reflectometry. In all cases the magnetization at the LSMO/STO interface is larger than the film bulk. We show that the interfacial magnetization is largestmore » across the LSMO/STO interfaces with (001) and (111) orientations, which have the largest net charge discontinuities across the interfaces. In contrast, the magnetization of LSMO/STO across the (110) interface, the orientation with no net charge discontinuity, is the smallest of the three orientations. We show that a magnetically degraded interface is not intrinsic to LSMO/STO heterostructures. Finally, the approach to use different crystallographic orientations provides a means to investigate the influence of charge discontinuity on the interfacial magnetization.« less

Orientation Control of Interfacial Magnetism at La 0.67Sr 0.33MnO 3/SrTiO 3 Interfaces

DOE PAGES

Guo, Er-Jia; Charlton, Timothy; Ambaye, Haile; ...

2017-05-16

Understanding the magnetism at the interface between a ferromagnet and an insulator is essential because the commonly posited magnetic “dead” layer close to an interface can be problematic in magnetic tunnel junctions. Previously, degradation of the magnetic interface was attributed to charge discontinuity across the interface. In this paper, the interfacial magnetism was investigated using three identically prepared La 0.67Sr 0.33MnO 3 (LSMO) thin films grown on different oriented SrTiO 3 (STO) substrates by polarized neutron reflectometry. In all cases the magnetization at the LSMO/STO interface is larger than the film bulk. We show that the interfacial magnetization is largestmore » across the LSMO/STO interfaces with (001) and (111) orientations, which have the largest net charge discontinuities across the interfaces. In contrast, the magnetization of LSMO/STO across the (110) interface, the orientation with no net charge discontinuity, is the smallest of the three orientations. We show that a magnetically degraded interface is not intrinsic to LSMO/STO heterostructures. Finally, the approach to use different crystallographic orientations provides a means to investigate the influence of charge discontinuity on the interfacial magnetization.« less

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.

Ali, Cunich: Halley's Churches: Halley and the London Queen Anne Churches

NASA Astrophysics Data System (ADS)

Ali, Jason R.; Cunich, Peter

2005-04-01

Edmond Halley's enormous contribution to science has received much attention. New research adds an intriguing chapter to his story and concerns his hitherto unexplored association with the baroque architectural visionary Nicholas Hawksmoor, and some important Temple-inspired churches that were built in London in the early 1700s. We argue that Christchurch Spitalfields and St Anne's Limehouse, which were both started in the summer of 1714, were aligned exactly eastwards using ``corrected'' magnetic-compass bearings and that Halley influenced or aided Hawksmoor. By this time the men had probably known each other for 30 years and had recently worked together on the Clarendon Building in Oxford. Despite there being more than 1500 years of Chinese and about 500 years of Western compass technology at the time, these probably represent the first constructions planned using a modern-day ``scientific'' technique. The research also throws light on Halley's contended religious position.

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.

Finding the right rocks on Mars

NASA Astrophysics Data System (ADS)

Hargraves, R. B.; Knudsen, J. M.; Madsen, M. B.; Bertelsen, P.

Locating a rock on the surface of Mars that bears unambiguous evidence of the existence—prior or present—of life on that planet is, understandably, the “Holy Grail” of NASAs sample return missions. Remote recognition of such a rock on Mars will not be easy. We do know, however, that present in the Martian crust—especially in the “Southern highlands”—is rock carrying strong natural remanent magnetization (NRM). Characterization of such magnetized rock has profound implications for adding to our knowledge about the origin and early evolution of the Martian interior, lithosphere, atmosphere, and possibly even Martian life forms [Ward and Brownlee, 2000]. Moreover, it should be possible to recognize such rocks by use of a simple magnetic compass mounted on a Rover.

Development of a microcomputer-based magnetic heading sensor

NASA Technical Reports Server (NTRS)

Garner, H. D.

1987-01-01

This paper explores the development of a flux-gate magnetic heading reference using a single-chip microcomputer to process heading information and to present it to the pilot in appropriate form. This instrument is intended to replace the conventional combination of mechanical compass and directional gyroscope currently in use in general aviation aircraft, at appreciable savings in cost and reduction in maintenance. Design of the sensing element, the signal processing electronics, and the computer algorithms which calculate the magnetic heading of the aircraft from the magnetometer data have been integrated in such a way as to minimize hardware requirements and simplify calibration procedures. Damping and deviation errors are avoided by the inherent design of the device, and a technique for compensating for northerly-turning-error is described.

Backscattering of decametric waves on magnetically oriented ionosphere inhomogeneities

NASA Astrophysics Data System (ADS)

Sivokon', V. P.

2017-05-01

The method of study of magnetically oriented ionosphere inhomogeneities based on the analysis of radar decametric emission backscattering on inhomogeneities is proposed. It is shown that certain conditions, including the orientation of the propagation route relative to the Earth's magnetic field lines and the polarization and frequency of the emitted wave, make possible resonant backscattering of radiolocation system emission on magnetically oriented ionosphere inhomogeneities. The paper presents the results of experimental observation of scattering in Kamchatka Peninsula. They demonstrated the opportunity to evaluate the extension of the scattering region, the vertical and horizontal components of the velocities of magnetically oriented inhomogeneities, and the frequency dependence of these parameters.

Orientation of Steel Fibers in Magnetically Driven Concrete and Mortar.

PubMed

Xue, Wen; Chen, Ju; Xie, Fang; Feng, Bing

2018-01-22

The orientation of steel fibers in magnetically driven concrete and magnetically driven mortar was experimentally studied in this paper using a magnetic method. In the magnetically driven concrete, a steel slag was used to replace the coarse aggregate. In the magnetically driven mortar, steel slag and iron sand were used to replace the fine aggregate. A device was established to provide the magnetic force. The magnetic force was used to rotate the steel fibers. In addition, the magnetic force was also used to vibrate the concrete and mortar. The effect of magnetic force on the orientation of steel fibers was examined by comparing the direction of fibers before and after vibration. The effect of magnetically driven concrete and mortar on the orientation of steel fibers was also examined by comparing specimens to normal concrete and mortar. It is shown that the fibers could rotate about 90° in magnetically driven concrete. It is also shown that the number of fibers rotated in magnetically driven mortar was much more than in mortar vibrated using a shaking table. A splitting test was performed on concrete specimens to investigate the effect of fiber orientation. In addition, a flexural test was also performed on mortar test specimens. It is shown that the orientation of the steel fibers in magnetically driven concrete and mortar affects the strength of the concrete and mortar specimens.

Orientation of Steel Fibers in Magnetically Driven Concrete and Mortar

PubMed Central

Xue, Wen; Chen, Ju; Xie, Fang; Feng, Bing

2018-01-01

The orientation of steel fibers in magnetically driven concrete and magnetically driven mortar was experimentally studied in this paper using a magnetic method. In the magnetically driven concrete, a steel slag was used to replace the coarse aggregate. In the magnetically driven mortar, steel slag and iron sand were used to replace the fine aggregate. A device was established to provide the magnetic force. The magnetic force was used to rotate the steel fibers. In addition, the magnetic force was also used to vibrate the concrete and mortar. The effect of magnetic force on the orientation of steel fibers was examined by comparing the direction of fibers before and after vibration. The effect of magnetically driven concrete and mortar on the orientation of steel fibers was also examined by comparing specimens to normal concrete and mortar. It is shown that the fibers could rotate about 90° in magnetically driven concrete. It is also shown that the number of fibers rotated in magnetically driven mortar was much more than in mortar vibrated using a shaking table. A splitting test was performed on concrete specimens to investigate the effect of fiber orientation. In addition, a flexural test was also performed on mortar test specimens. It is shown that the orientation of the steel fibers in magnetically driven concrete and mortar affects the strength of the concrete and mortar specimens. PMID:29361798

Modeling of magnetic particle orientation in magnetic powder injection molding

NASA Astrophysics Data System (ADS)

Doo Jung, Im; Kang, Tae Gon; Seul Shin, Da; Park, Seong Jin

2018-03-01

The magnetic micro powder orientation under viscous shear flow has been analytically understood and characterized into a new analytical orientation model for a powder injection molding process. The effects of hydrodynamic force from the viscous flow, external magnetic force and internal dipole-dipole interaction were considered to predict the orientation under given process conditions. Comparative studies with a finite element method proved the calculation validity with a partial differential form of the model. The angular motion, agglomeration and magnetic chain formation have been simulated, which shows that the effect of dipole-dipole interaction among powders on the orientation state becomes negligible at a high Mason number condition and at a low λ condition (the ratio of external magnetic field strength and internal magnetic moment of powder). Our developed model can be very usefully employed in the process analysis and design of magnetic powder injection molding.

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.

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.

Magnetosensitive neurons mediate geomagnetic orientation in Caenorhabditis elegans

PubMed Central

Vidal-Gadea, Andrés; Ward, Kristi; Beron, Celia; Ghorashian, Navid; Gokce, Sertan; Russell, Joshua; Truong, Nicholas; Parikh, Adhishri; Gadea, Otilia; Ben-Yakar, Adela; Pierce-Shimomura, Jonathan

2015-01-01

Many organisms spanning from bacteria to mammals orient to the earth's magnetic field. For a few animals, central neurons responsive to earth-strength magnetic fields have been identified; however, magnetosensory neurons have yet to be identified in any animal. We show that the nematode Caenorhabditis elegans orients to the earth's magnetic field during vertical burrowing migrations. Well-fed worms migrated up, while starved worms migrated down. Populations isolated from around the world, migrated at angles to the magnetic vector that would optimize vertical translation in their native soil, with northern- and southern-hemisphere worms displaying opposite migratory preferences. Magnetic orientation and vertical migrations required the TAX-4 cyclic nucleotide-gated ion channel in the AFD sensory neuron pair. Calcium imaging showed that these neurons respond to magnetic fields even without synaptic input. C. elegans may have adapted magnetic orientation to simplify their vertical burrowing migration by reducing the orientation task from three dimensions to one. DOI: http://dx.doi.org/10.7554/eLife.07493.001 PMID:26083711

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.

The geomagnetic environment in which sea turtle eggs incubate affects subsequent magnetic navigation behaviour of hatchlings.

PubMed

Fuxjager, Matthew J; Davidoff, Kyla R; Mangiamele, Lisa A; Lohmann, Kenneth J

2014-09-22

Loggerhead sea turtle hatchlings (Caretta caretta) use regional magnetic fields as open-ocean navigational markers during trans-oceanic migrations. Little is known, however, about the ontogeny of this behaviour. As a first step towards investigating whether the magnetic environment in which hatchlings develop affects subsequent magnetic orientation behaviour, eggs deposited by nesting female loggerheads were permitted to develop in situ either in the natural ambient magnetic field or in a magnetic field distorted by magnets placed around the nest. In orientation experiments, hatchlings that developed in the normal ambient field oriented approximately south when exposed to a field that exists near the northern coast of Portugal, a direction consistent with their migratory route in the northeastern Atlantic. By contrast, hatchlings that developed in a distorted magnetic field had orientation indistinguishable from random when tested in the same north Portugal field. No differences existed between the two groups in orientation assays involving responses to orbital movements of waves or sea-finding, neither of which involves magnetic field perception. These findings, to our knowledge, demonstrate for the first time that the magnetic environment present during early development can influence the magnetic orientation behaviour of a neonatal migratory animal. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

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.

The Chinese People’s Liberation Army and Information Warfare

DTIC Science & Technology

2014-03-01

information confrontation operations across the elec- tromagnetic spectrum. In doing so, as Dr. Wortzel’s monograph explains, the PLA used innovative means...and in- formation confrontation operations across the electro- magnetic spectrum. As this monograph explains, the PLA used innovative means to...depend on information technology. Naviga- tion and positioning is no longer done with compasses or sextants, maps , or charts; it is done with satellite

Insight into the Chemical Compass Mechanism of Cryptochromes by Computational Investigation

NASA Astrophysics Data System (ADS)

Pachter, Ruth; Hong, Gongyi

2014-03-01

In this work we investigated aspects of the light-dependent inclination compass, largely assumed in avian magnetic perception, e.g. of European robins. It is postulated that radical pairs (RPs) are formed in cryptochrome (Cry) photoreceptors that contain a redox-active flavin adenine dinucleotide (FAD) in proximity to a Trp triad. The hypothesis was previously rationalized theoretically for the Cry from Arabidopsis thaliana (AtCry1), and the pKa of the proximate residue (PR) to the FAD we derived from QM/MM MD simulations is consistent with this assumption. However, attempts to extrapolate the results to other species are complicated. In the Cry from Drosophila melanogaster (DmCry1), which demonstrated a magnetic response, the FAD anionic radical ground state differs from an oxidized form in AtCry1, and the PR to the FAD is Cys rather than Asp in AtCry1. Investigation for DmCry1 model compounds, showing potential feasibility of a RP mechanism, will be described, where the calculated excitation energy is in agreement with experiment. Involvement of a Tyr instead of Trp in the triad was also considered. Because Crys from the garden warbler form RPs, a RP mechanism was examined, based on a 3D structure derived by homology modeling and MD simulations.

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.

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.

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.

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

A new therapeutic community: development of a compassion-focussed and contextual behavioural environment.

PubMed

Veale, David; Gilbert, Paul; Wheatley, Jon; Naismith, Iona

2015-01-01

Social relationships and communities provide the context and impetus for a range of psychological developments, from genetic expression to the development of core self-identities. This suggests a need to think about the therapeutic changes and processes that occur within a community context and how communities can enable therapeutic change. However, the 'therapeutic communities' that have developed since the Second World War have been under-researched. We suggest that the concept of community, as a change process, should be revisited within mainstream scientific research. This paper briefly reviews the historical development of therapeutic communities and critically evaluates their current theory, practice and outcomes in a systematic review. Attention is drawn to recent research on the nature of evolved emotion regulation systems, the way these are entrained by social relationships, the importance of affiliative emotions in the regulation of threat and the role of fear of affiliative emotions in psychopathology. We draw on concepts from compassion-focussed therapy, social learning theory and functional analytical psychotherapy to consider how members of a therapeutic community can be aware of each other's acts of courage and respond using compassion. Living in structured and affiliative-orientated communities that are guided by scientific models of affect and self-regulation offers potential therapeutic advantages over individual outpatient therapy for certain client groups. This conclusion should be investigated further. Key Practitioner Message Current therapeutic community practice is not sufficiently evidence based and may not be maximizing the potential therapeutic value of a community. Compassion-focussed therapy and social learning theory offer new approaches for a therapeutic environment, involving an understanding of the role, nature and complexities of compassionate and affiliative relationships from staff and members, behavioural change guided by learning theory, a clear formulation based on threat-derived safety strategies, goal setting and positive reinforcement. Copyright © 2014 John Wiley & Sons, Ltd.

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.

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.

Spectral information as an orientation cue in dung beetles.

PubMed

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

2015-11-01

During the day, a non-uniform distribution of long and short wavelength light generates a colour gradient across the sky. This gradient could be used as a compass cue, particularly by animals such as dung beetles that rely primarily on celestial cues for orientation. Here, we tested if dung beetles can use spectral cues for orientation by presenting them with monochromatic (green and UV) light spots in an indoor arena. Beetles kept their original bearing when presented with a single light cue, green or UV, or when presented with both light cues set 180° apart. When either the UV or the green light was turned off after the beetles had set their bearing in the presence of both cues, they were still able to maintain their original bearing to the remaining light. However, if the beetles were presented with two identical green light spots set 180° apart, their ability to maintain their original bearing was impaired. In summary, our data show that ball-rolling beetles could potentially use the celestial chromatic gradient as a reference for orientation. © 2015 The Author(s).

Smart Optical Composite Materials: Dispersions of Metal-Organic Framework@Superparamagnetic Microrods for Switchable Isotropic-Anisotropic Optical Properties.

PubMed

Mandel, Karl; Granath, Tim; Wehner, Tobias; Rey, Marcel; Stracke, Werner; Vogel, Nicolas; Sextl, Gerhard; Müller-Buschbaum, Klaus

2017-01-24

A smart optical composite material with dynamic isotropic and anisotropic optical properties by combination of luminescence and high reflectivity was developed. This combination enables switching between luminescence and angle-dependent reflectivity by changing the applied wavelength of light. The composite is formed as anisotropic core/shell particles by coating superparamagnetic iron oxide-silica microrods with a layer of the luminescent metal-organic framework (MOF) 3 ∞ [Eu 2 (BDC) 3 ]·2DMF·2H 2 O (BDC 2- = 1,4-benzenedicarboxylate). The composite particles can be rotated by an external magnet. Their anisotropic shape causes changes in the reflectivity and diffraction of light depending on the orientation of the composite particle. These rotation-dependent optical properties are complemented by an isotropic luminescence resulting from the MOF shell. If illuminated by UV light, the particles exhibit isotropic luminescence while the same sample shows anisotropic optical properties when illuminated with visible light. In addition to direct switching, the optical properties can be tailored continuously between isotropic red emission and anisotropic reflection of light if the illuminating light is tuned through fractions of both UV and visible light. The integration and control of light emission modes within a homogeneous particle dispersion marks a smart optical material, addressing fundamental directions for research on switchable multifunctional materials. The material can function as an optic compass or could be used as an optic shutter that can be switched by a magnetic field, e.g., for an intensity control for waveguides in the visible range.

The Physics of Data: Can your degree in condensed matter theory get you a job at Google?

NASA Astrophysics Data System (ADS)

Byers, Jeff M.

2015-03-01

Migratory birds travel spectacular distances, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the sensing of such weak fields (25-65 microtesla) are scarce and in recent years just two proposals have emerged as frontrunners. One involves biogenic iron-containing nanoparticles; the other relies on the magnetic sensitivity of short-lived photochemical intermediates known as radical pairs. The latter began to attract attention following the proposal 15 years ago that the necessary physics and chemistry could take place in the bird's retina in specialised photoactive proteins called cryptochromes. The coherent dynamics of the electron-nuclear spin systems of pairs of photo-induced radicals is conjectured to form the basis of the sensing mechanism even though the interaction of an electron spin with the geomagnetic field is six orders of magnitude smaller than the thermal energy. The possibility that slowing decohering, entangled electron spins could form the basis of an important sensory mechanism has qualified radical pair magnetoreception for a place under the umbrella of ``Quantum Biology.'' In this talk, I will introduce the radical pair mechanism, comment on the roles of entanglement and quantum coherence, outline some of the experimental evidence for the cryptochrome hypothesis, and summarize what still needs to be done to determine whether birds (and maybe other animals) really do use a chemical compass to find their way around.

#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.

Subsurface Structure Determination of Geotermal Area in Siogung-ogung Samosir District by Using Magnetic Method

NASA Astrophysics Data System (ADS)

Tampubolon, Togi; Hutahaean, Juniar; Siregar, Suryani N. J.

2018-03-01

Underwater research often uses geomagnets. It is one of the geophysical methods for measuring magnetic field variations. This research was done to identify how the subsurface rock structure is and determine kinds of rock based on its susceptibility value in Siogung-ogung geothermal area, Pangururan, Samosir District. The tool measurement of total magnetic field called Proton Precission Magnetometer, positioning using Global Position System, and north axis determination using geological compass. Data collection was done randomly with total 51 measuring points obtained. Data analysis started with International geomagnetics Reference Field correction to obtain the total magnetic field anomaly. Then, the data analysis of total magnetic anomaly was done by using surfer program 12. To get a magnetic anomaly cross section used Magdc For Windows program. Magnetic measurement results indicated that the variation of magnetic field strength in each point with the lowest magnetic intensity value of 41785.67 nano tesla. The highest magnetic intensity value is 43140, 33. From the results of qualitative interpretation, the magnetic anomaly value is at -200.92 to 1154.45 whereas the quantitative interpretive results of model show the existence of degradation and andesitic rocks, with the value of susceptibility

Effect of cooling rate on magnetic domain structure and magnetic properties of Tb0.27Dy0.73Fe1.95 alloys solidified in high magnetic field

NASA Astrophysics Data System (ADS)

Liu, Tie; Dong, Meng; Gao, Pengfei; Xiao, Yubao; Yuan, Yi; Wang, Qiang

2018-05-01

In this work, Tb0.27Dy0.73Fe1.95 alloys were solidified in a high magnetic field of 4.4 T at various cooling rates. Changes in the magnetostriction, crystal orientation, magnetization, and magnetic domain of the solidified alloys were investigated. The application of the magnetic field can induce <111> orientation of (Tb, Dy)Fe2 phase. However, the effect of the magnetic field is strongly dependent on the cooling rate. The alloy solidified at 5 °C/min shows the highest magnetostriction, strongest <111> orientation, best contrast of light and dark in the domain image, and fastest magnetization, and followed in descending order by the alloys solidified at 1.5 °C/min and 60 °C/min. The change in the magnetostriction of the alloys can be attributed to the changes in crystal orientation and magnetic domain structure caused by both the magnetic field and cooling rate.

Magnetic Control of MOF Crystal Orientation and Alignment.

PubMed

Cheng, Fei; Marshall, Ellis S; Young, Adam J; Robinson, Peter J; Bouillard, Jean-Sebastien G; Adawi, Ali M; Vermeulen, Nicolaas A; Farha, Omar K; Reithofer, Michael R; Chin, Jia Min

2017-11-07

Most metal-organic frameworks (MOFs) possess anisotropic properties, the full exploitation of which necessitates a general strategy for the controllable orientation of such MOF crystals. Current methods largely rely upon layer-by-layer MOF epitaxy or tuning of MOF crystal growth on appropriate substrates, yielding MOFs with fixed crystal orientations. Here, the dynamic magnetic alignment of different MOF crystals (NH 2 -MIL-53(Al) and NU-1000) is shown. The MOFs were magnetized by electrostatic adsorption of iron oxide nanoparticles, dispersed in curable polymer resins (Formlabs 1+ clear resin/ Sylgard 184), magnetically oriented, and fixed by resin curing. The importance of crystal orientation on MOF functionality was demonstrated whereby magnetically aligned NU-1000/Sylgard 184 composite was excited with linearly polarized 405 nm light, affording an anisotropic fluorescence response dependent on the polarization angle of the excitation beam relative to NU-1000 crystal orientation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cooperative Localization on Computationally Constrained Devices

DTIC Science & Technology

2012-03-22

Fi hotspot capability. The HTC phone is equipped with the Qualcomm MSM7200A chipset which includes support for 802.11 b/g, digital compass and...Chipset Specifications Wi-Fi Qualcomm MSM7200A +802.11 b/g Bluetooth Qualcomm MSM7200A -Version 2.0 + EDR Accelerometer Bosh BMA 150 +25-1500Hz...Magnetic Field Compensation GPS Qualcomm MSM7200A +Enhanced filtering software to optimize accuracy +gpsOneXTRA for enhanced standalone

The Utilization of the Behavioral Sciences in Long Range Forecasting and Policy Planning

DTIC Science & Technology

1975-06-30

next. For purposes of analysis it is custcrrvary to place the observation and access interfaces together with either the inner or outer environment ...theorizing about governments the prinary object of analysis is the inner environment IE, IE £ Y x U (or some composition involving the inner...the compass, the environment is composed solely of magnetic lines of force. Environmental ^ changes which do not disturb these force lines are

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.

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

Magnetically guiding and orienting integrated chemical sensors

NASA Astrophysics Data System (ADS)

Anker, Jeffrey N.; Lee, Yong-Eun Koo; Kopelman, Raoul

2014-08-01

Fluorescent microsensors for detecting pH and oxygen were positioned and oriented using magnetic tweezers. These multifunctional integrated microsensors were fabricated by physically linking together nano-components including magnetic nanoparticles, fluorescent nanoparticles, and metal hemisphere-shells. Two such microsensors are magnetic roll-shaped polystyrene particles with 120 nm fluorescent oxygen-sensing ormosil nanospheres that are physically pressed ("breaded") into the roll surface, and 4-5 µm fluorescent microspheres that are capped with a 50 nm thick metal hemispherical shell. The magnetic tweezers consisted of an iron wire that was magnetized in an external magnetic field. Rotating this external field oriented and rotated the microsensors.

Evidence for instantaneous e-vector detection in the honeybee using an associative learning paradigm

PubMed Central

Sakura, Midori; Okada, Ryuichi; Aonuma, Hitoshi

2012-01-01

Many insects use the polarization pattern of the sky for obtaining compass information during orientation or navigation. E-vector information is collected by a specialized area in the dorsal-most part of the compound eye, the dorsal rim area (DRA). We tested honeybees' capability of learning certain e-vector orientations by using a classical conditioning paradigm with the proboscis extension reflex. When one e-vector orientation (CS+) was associated with sugar water, while another orientation (CS−) was not rewarded, the honeybees could discriminate CS+ from CS−. Bees whose DRA was inactivated by painting did not learn CS+. When ultraviolet (UV) polarized light (350 nm) was used for CS, the bees discriminated CS+ from CS−, but no discrimination was observed in blue (442 nm) or green light (546 nm). Our data indicate that honeybees can learn and discriminate between different e-vector orientations, sensed by the UV receptors of the DRA, suggesting that bees can determine their flight direction from polarized UV skylight during foraging. Fixing the bees' heads during the experiments did not prevent learning, indicating that they use an ‘instantaneous’ algorithm of e-vector detection; that is, the bees do not need to actively scan the sky with their DRAs (‘sequential’ method) to determine e-vector orientation. PMID:21733901

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.

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.

Microscopic observation of magnetic bacteria in the magnetic field of a rotating permanent magnet.

PubMed

Smid, Pieter; Shcherbakov, Valeriy; Petersen, Nikolai

2015-09-01

Magnetotactic bacteria are ubiquitous and can be found in both freshwater and marine environments. Due to intracellular chains of magnetic single domain particles, they behave like swimming compass needles. In external magnetic fields like the Earth's magnetic field, a torque is acting on the chain. This will cause the bacterium to be rotated and aligned with the external field. The swimming direction of magnetotactic bacteria can be controlled with external magnetic fields, which makes it convenient to study them under a light microscope. Usually, a special set of coils arranged around a light microscope is used to control the swimming magnetotactic bacteria. Here, we present a simple mechanical system with a permanent magnet, which produces a rotating magnetic field of nearly constant amplitude in the focal plane of a light microscope. The device is placed beside the light microscope and easily adaptable to almost any microscope and thus convenient for field experiments. To describe the trajectories qualitatively, a theoretical model of the trajectories is presented. This device can be used to control the swimming direction of magnetotactic bacteria and also for studying their magnetic and hydrodynamic properties.

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

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.

How Nemo finds home: the neuroecology of dispersal and of population connectivity in larvae of marine fishes.

PubMed

Leis, Jeffrey M; Siebeck, Ulrike; Dixson, Danielle L

2011-11-01

Nearly all demersal teleost marine fishes have pelagic larval stages lasting from several days to several weeks, during which time they are subject to dispersal. Fish larvae have considerable swimming abilities, and swim in an oriented manner in the sea. Thus, they can influence their dispersal and thereby, the connectivity of their populations. However, the sensory cues marine fish larvae use for orientation in the pelagic environment remain unclear. We review current understanding of these cues and how sensory abilities of larvae develop and are used to achieve orientation with particular emphasis on coral-reef fishes. The use of sound is best understood; it travels well underwater with little attenuation, and is current-independent but location-dependent, so species that primarily utilize sound for orientation will have location-dependent orientation. Larvae of many species and families can hear over a range of ~100-1000 Hz, and can distinguish among sounds. They can localize sources of sounds, but the means by which they do so is unclear. Larvae can hear during much of their pelagic larval phase, and ontogenetically, hearing sensitivity, and frequency range improve dramatically. Species differ in sensitivity to sound and in the rate of improvement in hearing during ontogeny. Due to large differences among-species within families, no significant differences in hearing sensitivity among families have been identified. Thus, distances over which larvae can detect a given sound vary among species and greatly increase ontogenetically. Olfactory cues are current-dependent and location-dependent, so species that primarily utilize olfactory cues will have location-dependent orientation, but must be able to swim upstream to locate sources of odor. Larvae can detect odors (e.g., predators, conspecifics), during most of their pelagic phase, and at least on small scales, can localize sources of odors in shallow water, although whether they can do this in pelagic environments is unknown. Little is known of the ontogeny of olfactory ability or the range over which larvae can localize sources of odors. Imprinting on an odor has been shown in one species of reef-fish. Celestial cues are current- and location-independent, so species that primarily utilize them will have location-independent orientation that can apply over broad scales. Use of sun compass or polarized light for orientation by fish larvae is implied by some behaviors, but has not been proven. Use of neither magnetic fields nor direction of waves for orientation has been shown in marine fish larvae. We highlight research priorities in this area. © The Author 2011. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.

Cholesteric-nematic transitions induced by a shear flow and a magnetic field

NASA Astrophysics Data System (ADS)

Zakhlevnykh, A. N.; Makarov, D. V.; Novikov, A. A.

2017-10-01

The untwisting of the helical structure of a cholesteric liquid crystal under the action of a magnetic field and a shear flow has been studied theoretically. Both factors can induce the cholesteric-nematic transition independently; however, the difference in the orienting actions of the magnetic field and the shear flow leads to competition between magnetic and hydrodynamic mechanisms of influence on the cholesteric liquid crystal. We have analyzed different orientations of the magnetic field relative to the direction of the flow in the shear plane. In a number of limiting cases, the analytic dependences are obtained for the pitch of the cholesteric helix deformed by the shear flow. The phase diagrams of the cholesteric-nematic transitions and the pitch of the cholesteric helix are calculated for different values of the magnetic field strength and the angle of orientation, the flow velocity gradient, and the reactive parameter. It is shown that the magnetic field stabilizes the orientation of the director in the shear flow and expands the boundaries of orientability of cholesterics. It has been established that the shear flow shifts the critical magnetic field strength of the transition. It is shown that a sequence of reentrant orientational cholesteric-nematic-cholesteric transitions can be induced by rotating the magnetic field in certain intervals of its strength and shear flow velocity gradients.

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.

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.

Highly controlled orientation of CaBi4Ti4O15 using a strong magnetic field

NASA Astrophysics Data System (ADS)

Suzuki, Tohru S.; Kimura, Masahiko; Shiratsuyu, Kosuke; Ando, Akira; Sakka, Yoshio; Sakabe, Yukio

2006-09-01

The texture of feeble magnetic ceramics can be controlled by a strong magnetic field. When the magnetic susceptibility of the c axis is smaller than that of the other axes, the c axis aligns perpendicular to the magnetic field; however, the direction is randomly oriented on the plane perpendicular to the magnetic field. The authors demonstrate in this letter that a highly controlled texture in bismuth titanate, which has a c-axis susceptibility smaller than the other axes, can be achieved using a two-step magnetic field procedure. This highly controlled orientation is effective for improving the electromechanical coupling coefficient.

Ambulatory position and orientation tracking fusing magnetic and inertial sensing.

PubMed

Roetenberg, Daniel; Slycke, Per J; Veltink, Peter H

2007-05-01

This paper presents the design and testing of a portable magnetic system combined with miniature inertial sensors for ambulatory 6 degrees of freedom (DOF) human motion tracking. The magnetic system consists of three orthogonal coils, the source, fixed to the body and 3-D magnetic sensors, fixed to remote body segments, which measure the fields generated by the source. Based on the measured signals, a processor calculates the relative positions and orientations between source and sensor. Magnetic actuation requires a substantial amount of energy which limits the update rate with a set of batteries. Moreover, the magnetic field can easily be disturbed by ferromagnetic materials or other sources. Inertial sensors can be sampled at high rates, require only little energy and do not suffer from magnetic interferences. However, accelerometers and gyroscopes can only measure changes in position and orientation and suffer from integration drift. By combing measurements from both systems in a complementary Kalman filter structure, an optimal solution for position and orientation estimates is obtained. The magnetic system provides 6 DOF measurements at a relatively low update rate while the inertial sensors track the changes position and orientation in between the magnetic updates. The implemented system is tested against a lab-bound camera tracking system for several functional body movements. The accuracy was about 5 mm for position and 3 degrees for orientation measurements. Errors were higher during movements with high velocities due to relative movement between source and sensor within one cycle of magnetic actuation.

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.

Cosmic Magnetic Fields - An Overview

NASA Astrophysics Data System (ADS)

Wielebinski, Richard; Beck, Rainer

Magnetic fields have been known in antiquity. Aristotle attributes the first of what could be called a scientific discussion on magnetism to Thales, who lived from about 625 BC. In China “magnetic carts” were in use to help the Emperor in his journeys of inspection. Plinius comments that in the Asia Minor province of Magnesia shepherds' staffs get at times “glued” to a stone, a alodestone. In Europe the magnetic compass came through the Arab sailors who met the Portuguese explorers. The first scientific treatise on magnetism, “De Magnete”, was published by William Gilbert who in 1600 described his experiments and suggested that the Earth was a huge magnet. Johannes Kepler was a correspondent of Gilbert and at times suggested that planetary motion was due to magnetic forces. Alas, this concept was demolished by Isaac Newton,who seeing the falling apple decided that gravity was enough. This concept of dealing with gravitational forces only remains en vogue even today. The explanations why magnetic effects must be neglected go from “magnetic energy is only 1% of gravitation” to “magnetic fields only complicate the beautiful computer solutions”. What is disregarded is the fact that magnetic effects are very directional(not omni-directional as gravity) and also the fact that magnetic fields are seen every where in our cosmic universe.

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.

Compassion fatigue, moral distress, and work engagement in surgical intensive care unit trauma nurses: a pilot study.

PubMed

Mason, Virginia M; Leslie, Gail; Clark, Kathleen; Lyons, Pat; Walke, Erica; Butler, Christina; Griffin, Martha

2014-01-01

Preparation for replacing the large proportion of staff nurses reaching retirement age in the next few decades in the United States is essential to continue delivering high-quality nursing care and improving patient outcomes. Retaining experienced critical care nurses is imperative to successfully implementing the orientation of new inexperienced critical care nurses. It is important to understand factors that affect work engagement to develop strategies that enhance nurse retention and improve the quality of patient care. Nurses' experience of moral distress has been measured in medical intensive care units but not in surgical trauma care units, where nurses are exposed to patients and families faced with sudden life-threatening, life-changing patient consequences.This pilot study is a nonexperimental, descriptive, correlational design to examine the effect of compassion satisfaction, compassion fatigue, moral distress, and level of nursing education on critical care nurses' work engagement. This is a partial replication of Lawrence's dissertation. The study also asked nurses to describe sources of moral distress and self-care strategies for coping with stress. This was used to identify qualitative themes about the nurse experiences. Jean Watson's theory of human caring serves as a framework to bring meaning and focus to the nursing-patient caring relationship.A convenience sample of 26 of 34 eligible experienced surgical intensive care unit trauma nurses responded to this survey, indicating a 77% response rate. Twenty-seven percent of the nurses scored high, and 73% scored average on compassion satisfaction. On compassion fatigue, 58% scored average on burnout and 42% scored low. On the secondary traumatic stress subscale, 38% scored average, and 62% scored low. The mean moral distress situations subscale score was 3.4, which is elevated. The mean 9-item Utrecht Work Engagement Scale total score, measuring work engagement, was 3.8, which is considered low.Content analysis was used to identify themes of Role Conflict With Management/Rules, Death and Suffering, Dealing With Violence in the Intensive Care Unit, Dealing With Family, Powerlessness, Physical Distress, and Medical Versus Nursing Values. Additional themes identified were caring, helping families, long-time interdependent relationships of colleagues, and satisfaction in trauma nursing.As work engagement increased, compassion satisfaction significantly increased, and burnout significantly decreased. Results of this study support moral distress as a clinically meaningful issue for surgical intensive care unit nurses. Moral distress scales were elevated, whereas work engagement scales were low. This finding was congruent with Lawrence's study and may reflect ongoing need for greater supports for experienced intensive care unit nurses, from both education and management. Future recommendations for research include examining the interaction of these variables in larger samples to examine additional explanatory factors as well as strategies for self-care, motivation, and behavior change.

[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.

An Adaptive Orientation Estimation Method for Magnetic and Inertial Sensors in the Presence of Magnetic Disturbances

PubMed Central

Fan, Bingfei; Li, Qingguo; Wang, Chao; Liu, Tao

2017-01-01

Magnetic and inertial sensors have been widely used to estimate the orientation of human segments due to their low cost, compact size and light weight. However, the accuracy of the estimated orientation is easily affected by external factors, especially when the sensor is used in an environment with magnetic disturbances. In this paper, we propose an adaptive method to improve the accuracy of orientation estimations in the presence of magnetic disturbances. The method is based on existing gradient descent algorithms, and it is performed prior to sensor fusion algorithms. The proposed method includes stationary state detection and magnetic disturbance severity determination. The stationary state detection makes this method immune to magnetic disturbances in stationary state, while the magnetic disturbance severity determination helps to determine the credibility of magnetometer data under dynamic conditions, so as to mitigate the negative effect of the magnetic disturbances. The proposed method was validated through experiments performed on a customized three-axis instrumented gimbal with known orientations. The error of the proposed method and the original gradient descent algorithms were calculated and compared. Experimental results demonstrate that in stationary state, the proposed method is completely immune to magnetic disturbances, and in dynamic conditions, the error caused by magnetic disturbance is reduced by 51.2% compared with original MIMU gradient descent algorithm. PMID:28534858

DOUBLE code simulations of emissivities of fast neutrals for different plasma observation view-lines of neutral particle analyzers on the COMPASS tokamak

NASA Astrophysics Data System (ADS)

Mitosinkova, K.; Tomes, M.; Stockel, J.; Varju, J.; Stano, M.

2018-03-01

Neutral particle analyzers (NPA) measure line-integrated energy spectra of fast neutral atoms escaping the tokamak plasma, which are a product of charge-exchange (CX) collisions of plasma ions with background neutrals. They can observe variations in the ion temperature T i of non-thermal fast ions created by additional plasma heating. However, the plasma column which a fast atom has to pass through must be sufficiently short in comparison with the fast atom’s mean-free-path. Tokamak COMPASS is currently equipped with one NPA installed at a tangential mid-plane port. This orientation is optimal for observing non-thermal fast ions. However, in this configuration the signal at energies useful for T i derivation is lost in noise due to the too long fast atoms’ trajectories. Thus, a second NPA is planned to be connected for the purpose of measuring T i. We analyzed different possible view-lines (perpendicular mid-plane, tangential mid-plane, and top view) for the second NPA using the DOUBLE Monte-Carlo code and compared the results with the performance of the present NPA with tangential orientation. The DOUBLE code provides fast-atoms’ emissivity functions along the NPA view-line. The position of the median of these emissivity functions is related to the location from where the measured signal originates. Further, we compared the difference between the real central T i used as a DOUBLE code input and the T iCX derived from the exponential decay of simulated energy spectra. The advantages and disadvantages of each NPA location are discussed.

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.

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.

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.

Magnetic Flux Circulation During Dawn-Dusk Oriented Interplanetary Magnetic Field

NASA Technical Reports Server (NTRS)

Mitchell, E. J.; Lopez, R. E.; Fok, M.-C.; Deng, Y.; Wiltberger, M.; Lyon, J.

2010-01-01

Magnetic flux circulation is a primary mode of energy transfer from the solar wind into the ionosphere and inner magnetosphere. For southward interplanetary magnetic field (IMF), magnetic flux circulation is described by the Dungey cycle (dayside merging, night side reconnection, and magnetospheric convection), and both the ionosphere and inner magnetosphere receive energy. For dawn-dusk oriented IMF, magnetic flux circulation is not well understood, and the inner magnetosphere does not receive energy. Several models have been suggested for possible reconnection patterns; the general pattern is: dayside merging; reconnection on the dayside or along the dawn/dusk regions; and, return flow on dayside only. These models are consistent with the lack of energy in the inner magnetosphere. We will present evidence that the Dungey cycle does not explain the energy transfer during dawn-dusk oriented IMF. We will also present evidence of how magnetic flux does circulate during dawn-dusk oriented IMF, specifically how the magnetic flux reconnects and circulates back.

How the 'warped' relationships between nurses' emotions, attitudes, social support and perceived organizational conditions impact customer orientation.

PubMed

Gountas, Sandra; Gountas, John

2016-02-01

Much research focuses on organizational culture and its impact on customer orientation or emotional states and their impact on job satisfaction and well-being. This study aims to combine the complex roles of nurses' emotion states and job satisfaction in a model that identifies the effects of standards for service delivery (organizational culture), supervisor and co-worker support and the development of customer orientation. A previous study examined the relationships between nurses' personal resources, job satisfaction and customer orientation. This study examines how these variables relate to organizational standards and social support. A cross-sectional survey using a self-completion questionnaire with validated, existing scales to measure standards for service delivery, supervisor and co-worker support, job satisfaction, empathic concern, emotional exhaustion and customer orientation. Nurses (159) completed the questionnaire in 2010. The data were analysed using WarpPLS, a structural equation modelling software package. The results indicate that the final model fits the data well and explains 84% of the variance in customer orientation. The findings show the importance of standard for service delivery (organizational culture), supervisor and co-worker support on customer orientation. Nurses' personal resources interact with these, particularly supervisor and co-worker support, to develop staff job satisfaction and empathy. The need for support mechanisms in stressful times is discussed. We propose that training in compassion and empathy would help leaders to model desirable attributes that contribute towards customer orientation. © 2015 John Wiley & Sons Ltd.

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.

Magnetically-assembled micro/mesopixels exhibiting light intensity enhancement in the (012) planes of fish guanine crystals

NASA Astrophysics Data System (ADS)

Chikashige, T.; Iwasaka, M.

2018-05-01

In this study, a new method was investigated to form light-reflecting dots at the micrometer scale using the magnetic orientations of biogenic guanine crystals obtained from fish skin and scales. The crystal platelets, possessing average dimensions of 5 μm×20 μm×100 nm, were dispersed in water and observed during exposure to vertical magnetic fields up to 5 T. The magnetic field direction was parallel to Earth's gravity, and allowed the narrowest edges of the crystals to be observed at the micrometer scale for the first time. The magnetic orientation process was initiated under conditions where the crystal platelets in water were laid on a glass substrate or where the platelets had random orientations. In the former case, the crystal platelets followed a two-stage magnetic orientation process where, in the first step, the platelet widths were aligned in the magnetic field direction. The second step required rotation of the ˜20-μm-long plates with respect to the Earth's gravity, where application of a 5 T magnetic field enabled their orientation. Real-time images of the magnetically aligning platelets provided new evidence that the crystal platelets also emitted reflected light from a very narrow window at two crystal planes (i.e., (0 1 ¯ 2 ¯ ) and (0 1 ¯ 2 )). In the latter case with random platelet orientation, spatially-condensed light-reflecting dots appeared while the guanine crystal platelets were floating and maintaining their orientation. The technique developed for controlling light-reflecting microscale objects in an aqueous medium can be applied to produce a type of microfluidic optical tool.

Effect of orientational ordering of magnetic nanoemulsions immobilized in agar gel on magnetic hyperthermia

NASA Astrophysics Data System (ADS)

Lahiri, B. B.; Ranoo, Surojit; Philip, John

2018-04-01

Magnetic nanoemulsions of droplet size ∼200 nm, loaded with single domain superparamagnetic nanoparticles (MNP), are potential candidates for multimodal hyperthermia due to availability of large loading volume and enhanced permeation and retention (EPR) in the cancerous tissues. In such nanoemulsions, radio frequency alternating magnetic field induced heating occur at two entirely different length scales, viz. Neel-Brown relaxation of the dispersed MNP and Brownian relaxation of emulsion droplets. Here we study the effects of orientation ordering or texturing of droplets, immobilized in a tissue mimicking agar matrix, on the field induced heating efficiency. A higher specific absorption rate (maximum ∼73 ± 2 W/gFe) is observed for droplets orientated parallel to the direction of the alternating magnetic field because of the enhancement of effective uniaxial anisotropy energy density and increased effective relaxation time. For identical and non-interacting MNP oriented parallel to the external DC magnetic field, a threefold increase in the effective uniaxial anisotropy energy density and ∼20-30% increased specific absorption rate are observed as compared to those oriented perpendicular to the magnetic field. Magnetic force microscopy images showed that the spherical morphology of the droplets remains intact even after orientational ordering and average topographic height of the droplets are found to be ∼220 (±17) nm, which is in good agreement with the most probable size obtained from dynamic light scattering. The residual volume magnetization of the emulsion droplets is found to be 1.1 × 10-6 emu/cc, indicating the superparamagnetic nature of the droplets in tissue equivalent environment. The observed increase in heating efficiency of the immobilized and oriented emulsion droplets shows promising applications in multimodal hyperthermia therapy because of the requirement of lower dose of MNP and shorter treatment time.

Two-stage magnetic orientation of uric acid crystals as gout initiators

NASA Astrophysics Data System (ADS)

Takeuchi, Y.; Miyashita, Y.; Mizukawa, Y.; Iwasaka, M.

2014-01-01

The present study focuses on the magnetic behavior of uric acid crystals, which are responsible for gout. Under a sub-Tesla (T)-level magnetic field, rotational motion of the crystals, which were caused by diamagnetic torque, was observed. We used horizontal magnetic fields with a maximum magnitude of 500 mT generated by an electromagnet to observe the magnetic orientation of the uric acid microcrystals by a microscope. The uric acid crystals showed a perpendicular magnetic field orientation with a minimum threshold of 130 mT. We speculate that the distinct diamagnetic anisotropy in the uric acid crystals resulted in their rotational responses.

Sun compass error model

NASA Technical Reports Server (NTRS)

Blucker, T. J.; Ferry, W. W.

1971-01-01

An error model is described for the Apollo 15 sun compass, a contingency navigational device. Field test data are presented along with significant results of the test. The errors reported include a random error resulting from tilt in leveling the sun compass, a random error because of observer sighting inaccuracies, a bias error because of mean tilt in compass leveling, a bias error in the sun compass itself, and a bias error because the device is leveled to the local terrain slope.

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.

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.

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.

Magnetic effect on dancing bees

NASA Technical Reports Server (NTRS)

Lindauer, M.; Martin, H.

1972-01-01

Bee sensitivity to the earth's magnetic field is studied. Data cover sensitivity range and the use of magnetoreception for orientation purposes. Experimental results indicate bee orientation is aided by gravity fields when the magnetic field is compensated.

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…

Noncontact orientation of objects in three-dimensional space using magnetic levitation

PubMed Central

Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K.; Soh, Siowling; Whitesides, George M.

2014-01-01

This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media. PMID:25157136

Noncontact orientation of objects in three-dimensional space using magnetic levitation.

PubMed

Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K; Soh, Siowling; Whitesides, George M

2014-09-09

This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media.

Rotating magnetizations in electrical machines: Measurements and modeling

NASA Astrophysics Data System (ADS)

Thul, Andreas; Steentjes, Simon; Schauerte, Benedikt; Klimczyk, Piotr; Denke, Patrick; Hameyer, Kay

2018-05-01

This paper studies the magnetization process in electrical steel sheets for rotational magnetizations as they occur in the magnetic circuit of electrical machines. A four-pole rotational single sheet tester is used to generate the rotating magnetic flux inside the sample. A field-oriented control scheme is implemented to improve the control performance. The magnetization process of different non-oriented materials is analyzed and compared.

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.

Magnetic field-directed hybrid anisotropic nanocomposites.

PubMed

Gong, Maogang; Zhang, Jingming; Ren, Shenqiang

2018-08-24

A facile bottom-up approach is developed to grow magnetic metallic Cu/FeCo (core/shell) nanowires, where their distribution and orientation can be controlled by magnetic field. The nanocomposites consisting of a ferroelectric polymer matrix and magnetic nanowire arrays exhibit the orientation-controlled anisotropy and interfacial magnetoelectric coupling effect.

Radial arm strike rail

DOEpatents

McKeown, Mark H.; Beason, Steven C.

1991-01-01

The radial arm strike rail assembly is a system for measurement of bearings, directions, and stereophotography for geologic mapping, particularly where magnetic compasses are not appropriate. The radial arm, pivoting around a shaft axis, provides a reference direction determination for geologic mapping and bearing or direction determination. The centerable and levelable pedestal provide a base for the radial arm strike rail and the telescoping camera pedestal. The telescoping feature of the radial arm strike rail allows positioning the end of the rail for strike direction or bearing measurement with a goniometer.

Cetacean beachings correlate with geomagnetic disturbances in Earth's magnetosphere: an example of how astronomical changes impact the future of life

NASA Astrophysics Data System (ADS)

Ferrari, Thomas E.

2017-04-01

The beaching and stranding of whales and dolphins around the world has been mystifying scientists for centuries. Although many theories have been proposed, few are substantiated by unequivocal statistical evidence. Advances in the field of animal magnetoreception have established that many organisms, including cetaceans, have an internal `compass,' which they use for orientation when traveling long distances. Astrobiology involves not only the origin and distribution of life in the universe, but also the scientific study of how extraterrestrial conditions affect evolution of life on planet Earth. The focus of this study is how cetacean life is influenced by disturbances in its environment that originate from an astrological phenomenon - in the present study that involves solar flares and cetacean beachings. Solar storms are caused by major coronal eruptions on the Sun. Upon reaching Earth, they cause disturbances in Earth's normally stable magnetosphere. Unable to follow an accurate magnetic bearing under such circumstances, cetaceans lose their compass reading while travelling and, depending on their juxtaposition and nearness to land, eventually beach themselves. (1) This hypothesis was supported by six separate, independent surveys of beachings: (A) in the Mediterranean Sea, (B) the northern Gulf of Mexico, (C) the east and (D) west coasts of the USA and two surveys (E and F) from around the world. When the six surveys were pooled (1614 strandings), a highly significant correlation (R 2 = 0.981) of when strandings occurred with when major geomagnetic disturbances in Earth's magnetosphere occurred was consistent with this hypothesis. (2) Whale and dolphin strandings in the northern Gulf of Mexico and the east coast of the USA were correlated (R 2 = 0.919, R 2 = 0.924) with the number of days before and after a geomagnetic storm. (3) Yearly strandings were correlated with annual geomagnetic storm days. (4) Annual beachings of cetaceans from 1998 to 2012 were linearly correlated (R 2 = 0.751) with frequency of annual sunspot numbers. Thus, consistently strong statistical correlation evidence indicates that an astronomical phenomenon - solar flares - can cause cetaceans to change their behaviour and become disoriented, which eventually causes them to swim onto a shore and beach themselves.

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.

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

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.

Removal of the Magnetic Dead Layer by Geometric Design

DOE PAGES

Guo, Er-jia; Roldan, Manuel; Charlton, Timothy R.; ...

2018-05-28

The proximity effect is used to engineer interface effects such as magnetoelectric coupling, exchange bias, and emergent interfacial magnetism. However, the presence of a magnetic “dead layer” adversely affects the functionality of a heterostructure. Here in this paper, it is shown that by utilizing (111) polar planes, the magnetization of a manganite ultrathin layer can be maintained throughout its thickness. Combining structural characterization, magnetometry measurements, and magnetization depth profiling with polarized neutron reflectometry, it is found that the magnetic dead layer is absent in the (111)-oriented manganite layers, however, it occurs in the films with other orientations. Quantitative analysis ofmore » local structural and elemental spatial evolutions using scanning transmission electron microscopy and electron energy loss spectroscopy reveals that atomically sharp interfaces with minimal chemical intermixing in the (111)-oriented superlattices. The polar discontinuity across the (111) interfaces inducing charge redistribution within the SrTiO 3 layers is suggested, which promotes ferromagnetism throughout the (111)-oriented ultrathin manganite layers. The approach of eliminating problematic magnetic dead layers by changing the crystallographic orientation suggests a conceptually useful recipe to engineer the intriguing physical properties of oxide interfaces, especially in low dimensionality.« less

Removal of the Magnetic Dead Layer by Geometric Design

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

Guo, Er-jia; Roldan, Manuel; Charlton, Timothy R.

The proximity effect is used to engineer interface effects such as magnetoelectric coupling, exchange bias, and emergent interfacial magnetism. However, the presence of a magnetic “dead layer” adversely affects the functionality of a heterostructure. Here in this paper, it is shown that by utilizing (111) polar planes, the magnetization of a manganite ultrathin layer can be maintained throughout its thickness. Combining structural characterization, magnetometry measurements, and magnetization depth profiling with polarized neutron reflectometry, it is found that the magnetic dead layer is absent in the (111)-oriented manganite layers, however, it occurs in the films with other orientations. Quantitative analysis ofmore » local structural and elemental spatial evolutions using scanning transmission electron microscopy and electron energy loss spectroscopy reveals that atomically sharp interfaces with minimal chemical intermixing in the (111)-oriented superlattices. The polar discontinuity across the (111) interfaces inducing charge redistribution within the SrTiO 3 layers is suggested, which promotes ferromagnetism throughout the (111)-oriented ultrathin manganite layers. The approach of eliminating problematic magnetic dead layers by changing the crystallographic orientation suggests a conceptually useful recipe to engineer the intriguing physical properties of oxide interfaces, especially in low dimensionality.« less

An orientation measurement method based on Hall-effect sensors for permanent magnet spherical actuators with 3D magnet array.

PubMed

Yan, Liang; Zhu, Bo; Jiao, Zongxia; Chen, Chin-Yin; Chen, I-Ming

2014-10-24

An orientation measurement method based on Hall-effect sensors is proposed for permanent magnet (PM) spherical actuators with three-dimensional (3D) magnet array. As there is no contact between the measurement system and the rotor, this method could effectively avoid friction torque and additional inertial moment existing in conventional approaches. Curved surface fitting method based on exponential approximation is proposed to formulate the magnetic field distribution in 3D space. The comparison with conventional modeling method shows that it helps to improve the model accuracy. The Hall-effect sensors are distributed around the rotor with PM poles to detect the flux density at different points, and thus the rotor orientation can be computed from the measured results and analytical models. Experiments have been conducted on the developed research prototype of the spherical actuator to validate the accuracy of the analytical equations relating the rotor orientation and the value of magnetic flux density. The experimental results show that the proposed method can measure the rotor orientation precisely, and the measurement accuracy could be improved by the novel 3D magnet array. The study result could be used for real-time motion control of PM spherical actuators.

Magnetically induced orientation of mesochannels in mesoporous silica films at 30 tesla.

PubMed

Yamauchi, Yusuke; Sawada, Makoto; Komatsu, Masaki; Sugiyama, Atsushi; Osaka, Tetsuya; Hirota, Noriyuki; Sakka, Yoshio; Kuroda, Kazuyuki

2007-12-03

We demonstrate the magnetically induced orientation of mesochannels in mesoporous silica films prepared with low-molecular-weight surfactants under an extremely high magnetic field of 30 T. This process is principally applicable to any type of surfactant that has magnetic anisotropy because such a high magnetic field provides sufficient magnetic energy for smooth magnetic orientation. Hexadecyltrimethylammonium bromide (CTAB) and polyoxyethylene-10-cetyl ether (Brij 56) were used as cationic and nonionic surfactants, respectively. According to XRD and cross-sectional TEM, mesochannels aligned perpendicular to the substrates were observed in films prepared with low-molecular-weight surfactants, although the effect was incomplete. The evolution of these types of films should lead to future applications such as highly sensitive chemical sensors and selective separation.

Pulse-driven magnetoimpedance sensor detection of cardiac magnetic activity.

PubMed

Nakayama, Shinsuke; Sawamura, Kenta; Mohri, Kaneo; Uchiyama, Tsuyoshi

2011-01-01

This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI) sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT) level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG). The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.

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…

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.

Finding joy in social work. II: Intrapersonal sources.

PubMed

Pooler, David Kenneth; Wolfer, Terry; Freeman, Miriam

2014-07-01

Despite the social work profession's strengths orientation, research on its workforce tends to focus on problems (for example, depression, problem drinking, compassion fatigue, burnout). In contrast, this study explored ways in which social workers find joy in their work. The authors used an appreciative inquiry approach, semistructured interviews (N = 26), and a collaborative grounded theory method of analysis. Participants identified interpersonal (making connections and making a difference) and intrapersonal (making meaning and making a life) sources of joy and reflected significant personal initiative in the process of finding joy. The authors present findings regarding these intrapersonal sources of joy.

Morphology and orientational behavior of silica-coated spindle-type hematite particles in a magnetic field probed by small-angle X-ray scattering.

PubMed

Reufer, Mathias; Dietsch, Hervé; Gasser, Urs; Hirt, Ann; Menzel, Andreas; Schurtenberger, Peter

2010-04-15

Form factor and magnetic properties of silica-coated spindle-type hematite nanoparticles are determined from SAXS measurements with applied magnetic field and magnetometry measurements. The particle size, polydispersity and porosity are determined using a core-shell model for the form factor. The particles are found to align with their long axis perpendicular to the applied field. The orientational order is determined from the SAXS data and compared to the orientational order obtained from magnetometry. The direct access to both, the orientational order of the particles, and the magnetic moments allow one to determine the magnetic properties of the individual spindle-type hematite particles. We study the influence of the silica coating on the magnetic properties and find a fundamentally different behavior of silica-coated particles. The silica coating reduces the effective magnetic moment of the particles. This effect is enhanced with field strength and can be explained by superparamagnetic relaxation in the highly porous particles.