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Sample records for cadherin-11 controls otolith

  1. Cadherin-11 localizes to focal adhesions and promotes cell–substrate adhesion

    Science.gov (United States)

    Langhe, Rahul P.; Gudzenko, Tetyana; Bachmann, Michael; Becker, Sarah F.; Gonnermann, Carina; Winter, Claudia; Abbruzzese, Genevieve; Alfandari, Dominique; Kratzer, Marie-Claire; Franz, Clemens M.; Kashef, Jubin

    2016-01-01

    Cadherin receptors have a well-established role in cell–cell adhesion, cell polarization and differentiation. However, some cadherins also promote cell and tissue movement during embryonic development and tumour progression. In particular, cadherin-11 is upregulated during tumour and inflammatory cell invasion, but the mechanisms underlying cadherin-11 stimulated cell migration are still incompletely understood. Here, we show that cadherin-11 localizes to focal adhesions and promotes adhesion to fibronectin in Xenopus neural crest, a highly migratory embryonic cell population. Transfected cadherin-11 also localizes to focal adhesions in different mammalian cell lines, while endogenous cadherin-11 shows focal adhesion localization in primary human fibroblasts. In focal adhesions, cadherin-11 co-localizes with β1-integrin and paxillin and physically interacts with the fibronectin-binding proteoglycan syndecan-4. Adhesion to fibronectin mediated by cadherin-11/syndecan-4 complexes requires both the extracellular domain of syndecan-4, and the transmembrane and cytoplasmic domains of cadherin-11. These results reveal an unexpected role of a classical cadherin in cell–matrix adhesion during cell migration. PMID:26952325

  2. ZAG-Otolith: Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control during Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, S. J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, <20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. One result of this study will be to characterize the variability (gain, asymmetry) in both otolithocular responses and motion perception during variable radius centrifugation, and measure the time course of postflight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual

  3. ZAG-Otolith: Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control during Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, S. J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. One result of this study will be to characterize the variability (gain, asymmetry) in both otolithocular responses and motion perception during variable radius centrifugation, and measure the time course of postflight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved with vibrotactile feedback of orientation.

  4. Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control During Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, Scott J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, less than 20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. One result of this study will be to characterize the variability (gain, asymmetry) in both otolith-ocular responses and motion perception during variable radius centrifugation, and measure the time course of post-flight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved

  5. Parabolic flight reveals independent binocular control of otolith-induced eye torsion

    Science.gov (United States)

    Markham, C. H.; Diamond, S. G.; Stoller, D. F.

    2000-01-01

    To examine otolith-governed ocular torsion in hyper- and hypogravity, eight subjects, including two astronauts, underwent parabolic flight while seated upright with head fixed. A mask fitted with two video cameras provided synchronized images of both eyes at a rate of 25/sec during 15 parabolas, the individual parabolas separated by a few minutes of level 1 G flight. Three main findings emerged: 1) After the first parabola, most subjects showed differential torsional offset of the two eyes in the 1 G portions between parabolas, compared to the conjugate baseline position of the eyes prior to the first parabola. 2) Changes in binocular torsion in the 0 G and 1.8 G portions of parabolic flight revealed in most subjects systematic reversal of direction. The reversal was consistent within, but not across subjects. 3) Disconjugacy defined as the moment-to-moment difference in the movements of the two eyes, and evaluated without the contribution of the differential offset, found two subjects with relatively high disconjugacy scores, and the remaining six with low scores. On the basis of prior studies (9, 20), we would predict the first two would be subject to SMS, the remainder not. The two astronauts, who did not have SMS on their space missions, fell into the low scoring group. We propose that the disconjugacies may be due to intrinsic asymmetries in the otolith receptors on the two sides of the head, which appear to be independently linked to the extraocular muscles of the two eyes, a phenomenon masked in normal 1 G states by adaptation. The apparently independent control of the two sides cannot be detected by the simpler and more common monocular studies.

  6. AP-1 Transcription Factors c-FOS and c-JUN Mediate GnRH-Induced Cadherin-11 Expression and Trophoblast Cell Invasion.

    Science.gov (United States)

    Peng, Bo; Zhu, Hua; Ma, Liyang; Wang, Yan-Ling; Klausen, Christian; Leung, Peter C K

    2015-06-01

    GnRH is expressed in first-trimester human placenta and increases cell invasion in extravillous cytotrophoblasts (EVTs). Invasive phenotypes have been reported to be regulated by transcription factor activator protein 1 (AP-1) and mesenchymal cadherin-11. The aim of our study was to investigate the roles of AP-1 components (c-FOS/c-JUN) and cadherin-11 in GnRH-induced cell invasion in human EVT cells. Phosphorylated c-FOS and phosphorylated c-JUN were detected in the cell column regions of human first-trimester placental villi by immunohistochemistry. GnRH treatment increased c-FOS, c-JUN, and cadherin-11 mRNA and protein levels in immortalized EVT (HTR-8/SVneo) cells. Moreover, GnRH treatment induced c-FOS and c-JUN protein phosphorylation and nuclear accumulation. Pretreatment with antide, a GnRH antagonist, attenuated GnRH-induced cadherin-11 expression. Importantly, basal and GnRH-induced cadherin-11 expression and cell invasion were reduced by small interfering RNA-mediated knockdown of c-FOS, c-JUN, and cadherin-11 in HTR-8/SVneo cells. Our results suggest that GnRH induces the expression and phosphorylation of the AP-1 transcription factors c-FOS and c-JUN in trophoblast cells, which contributes to GnRH-induced elevation of cadherin-11 expression and cell invasion. PMID:25794160

  7. Cadherin-11 contributes to pulmonary fibrosis: potential role in TGF-β production and epithelial to mesenchymal transition

    OpenAIRE

    Daniel J. Schneider; Wu, Minghua; Thuy T Le; Cho, Seo-Hee; Brenner, Michael B.; Blackburn, Michael R.; Agarwal, Sandeep K

    2012-01-01

    Pulmonary fibrosis, characterized by excess deposition of extracellular matrix by myofibroblasts, is a serious component of chronic lung diseases. Cadherin-11 (CDH11) is increased in wound healing and fibrotic skin. We hypothesized that CDH11 is increased in pulmonary fibrosis and contributes its development. CDH11 expression was assessed in lung tissue from idiopathic pulmonary fibrosis patients. The role of CDH11 in lung fibrosis was determined using the bleomycin model of pulmonary fibrosi...

  8. Different pH-dependencies of the two synaptic adhesion molecules N-cadherin and cadherin-11 and the possible functional implication for long-term potentiation

    DEFF Research Database (Denmark)

    Baumgartner, Werner; Osmanagic, Armin; Gebhard, Marita;

    2013-01-01

    Ca(2+) -dependent adhesion molecules, cadherins, localised at synaptic sites are critically involved in long-term potentiation (LTP). N-cadherin is thought to promote LTP whereas cadherin-11 seems to counteract LTP. Since high synaptic activity is accompanied by local transient changes of the p...

  9. Bottomfish Otolith Archive

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ryan Nichols (FBSAB LHP) collected this data set and it contains information on fish otoliths collected from previous research cruises and stored in Aiea Research...

  10. Umbilical Cord-Derived Mesenchymal Stem Cells Inhibit Cadherin-11 Expression by Fibroblast-Like Synoviocytes in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Cheng Zhao

    2015-01-01

    Full Text Available This study aimed to determine whether umbilical cord-derived mesenchymal stem cells (UCMSC regulate Cadherin-11 (CDH11 expression by fibroblast-like synoviocytes (FLS in rheumatoid arthritis (RA. FLS were isolated from the synovium of RA and osteoarthritis (OA patients. FLS from RA patients were cocultured with UCMSC in a transwell system. CDH11 mRNA levels in FLS were tested, and levels of soluble factors expressed by UCMSC, such as indoleamine 2,3-dioxygenase (IDO, hepatocyte growth factor (HGF, and interleukin- (IL- 10, were determined. IDO, HGF, and IL-10 were upregulated in cocultures, so that appropriate inhibitors were added before determination of CDH11 expression. The effects of UCMSC on arthritis were investigated in the collagen-induced arthritis (CIA model in Wistar rats. FLS from RA patients expressed higher CDH11 levels than those from OA patients, and this effect was suppressed by UCMSC. The inhibitory effect of UCMSC on CDH11 expression by FLS was abolished by suppression of IL-10 activity. CDH11 expression in synovial tissues was higher in the context of CIA than under basal conditions, and this effect was prevented by UCMSC administration. IL-10 mediates the inhibitory effect of UCMSC on CDH11 expression by FLS, and this mechanism might be targeted to ameliorate arthritis.

  11. OTOLITHS AND THEIR APPLICATIONS IN FISHERY SCIENCE

    Directory of Open Access Journals (Sweden)

    Paola Rodriguez Mendoza

    2006-07-01

    Full Text Available Otoliths are structures located in the inner ear cavity of all teleost fish and serve as a balance organ and also aid in hearing. They have been used traditionally to obtain information about the taxon, age and size of fishes. This is very important because age, growth rate, and mortality rate are three of the most influential life history characteristics controlling the productivity of fish populations. Besides age and growth determination, otoliths have been the object of study in many different fields, such as fish biology (hearing and balance in fishes, larval fish ecology, species identification, fish stock identification and environmental reconstruction of the fish habitat. Thus, the purpose of this paper is to provide an overview of the traditional and current applications of the otoliths. Also, a short description of the traditional methods for age determination is included.

  12. High‐resolution stock discrimination of Atlantic herring (Clupea harengus) based on otolith shape, microstructure, and genetic markers

    DEFF Research Database (Denmark)

    Mosegaard, Henrik; Worsøe Clausen, Lotte; Bekkevold, Dorte

    2012-01-01

    between populations, which suggest genetic control as well. Thus otolith shape serves as a population marker, suitable for individual assignment. Here we use otolith morphological characteristics (otolith shape and larval otolith microstructure) combined with genetic markers to discriminate between...... different populations of Atlantic herring (Clupea harengus) in the western Baltic and adjacent waters. We analyse a baseline (spawning individuals from several populations validated by genetic markers) for separation of adult herring (2+) based on otolith shape and juveniles using genetically validated...... otolith shape characteristics as separation parameters. Otolith shape was found to clearly discriminate between individuals at all ages from different spawning populations. The identified distances between populations based on otolith shape matched previously obtained genetic distances and were, when...

  13. A critical period for gravitational effects on otolith formation

    Science.gov (United States)

    Wiederhold, M.; Harrison, J.

    Gravity and linear acceleration are sensed in fish by the saccule, utricle (as in mammals) and lagena, each with a solid otolith. Previous experiments in which eggs or larvae of a marine mollusk ( plysia) or fish larvae were raised on aA centrifuge, demonstrated that the size of the otolith or statoconia (in Aplysia) were reduced, in a graded manner, as the gfield was increased, suggesting that some- control mechanism was acting to normalize the weight of the mass. Pre-mated adult female swordtail fish (Xiphophorus helleri) were flown in the CEBAS aquarium system on space shuttle missions STS 89 and STS-90 (Neurolab). Developing- larvae were removed from the adult ovaries after shuttle landing. Otolith sizes were compared between ground- and flight -reared larvae of similar sizes. For later-stage swordtail larvae, with spine lengths from 3 to 6 mm from STS-90 (16 days), the growth of the otolith with increasing spine length was significantly greater in the flight - reared fish for all three otoliths, from the saccule (saggita), utricle (lapillus) and lagena (astericus). However, juvenile fish, 1 cm long at launch, showed no significant difference in otolith size between flight - and ground-reared animals. In very early stage larvae from STS-89 (9 days), with spine length of 1.5 to 3.5 mm, the utricular and saccular otoliths were actually larger in the ground-reared larvae. Thus, it appears that late-stage fish embryos reared in space do produce larger-than - normal otoliths, apparently in an attempt to c mpensate for the reduced weight ofo the test mass in space. However, the results from very early-stage larvae and juvenile fish suggest that there is a fairly short critical period during which altered gravity can affect the size of the test mass. Recent studies on the development of the inner ear of the zebrafish (Danio raria) may explain the critical period for gravitational effects on otolith growth. By 16 hours after zebrafish fertilization (at 28.5 o

  14. Vestibular reflexes of otolith origin

    Science.gov (United States)

    Wilson, Victor J.

    1988-01-01

    The vestibular system and its role in the maintenance of posture and in motion sickness is investigated using cats as experimental subjects. The assumption is that better understanding of the physiology of vestibular pathways is not only of intrinsic value, but will help to explain and eventually alleviate the disturbances caused by vestibular malfunction, or by exposure to an unusual environment such as space. The first project deals with the influence on the spinal cord of stimulation of the vestibular labyrinth, particularly the otoliths. A second was concerned with the properties and neural basis of the tonic neck reflex. These two projects are related, because vestibulospinal and tonic neck reflexes interact in the maintenance of normal posture. The third project began with an interest in mechanisms of motion sickness, and eventually shifted to a study of central control of respiratory muscles involved in vomiting.

  15. North American sturgeon otolith morphology

    Science.gov (United States)

    Chalupnicki, Marc A.; Dittman, Dawn E.

    2016-01-01

    Accurate expedient species identification of deceased sturgeon (Acipenseridae) when external physical characteristic analysis is inconclusive has become a high priority due to the endangered or threatened status of sturgeon species around the world. Examination of otoliths has provided useful information to aid in population management, age and size-class analysis, understanding predator–prey interactions, and archeological research in other fish species. The relationship between otolith characteristics and sturgeon species has remained unknown. Therefore, we analyzed the shape of otoliths from the eight species of sturgeon found in North America to test the utility of otolith characteristic morphology in species identification. There were distinct differences in the size and shape of the otoliths between species of sturgeon with little shape variation among individuals of the same species. The relationship between otolith length axes was linear, and most of the variability was explained by a Log (axis + 1) transformation of the x and y axes (r2 = 0.8983) using the equation y = 0.73x + 0.0612. Images of otoliths from all eight North American species are presented to assist in the identification process.

  16. Plasticity of the human otolith-ocular reflex

    Science.gov (United States)

    Wall, C. 3rd; Smith, T. R.; Furman, J. M.

    1992-01-01

    The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

  17. Magnetic elements in otoliths of lagena and their function

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Yasuo [Hiroshima City Hospital Affairs Bureau, Hiroshima (Japan)

    2002-07-01

    The mystery of pigeons' homing abilities has been the subject of much interest, and it is widely believed that information from the earth's magnetic field may be involved. However, no specific magnetic sensory organ has yet been identified. The recent finding of magnetic materials in the lagenal otolith of fishes and birds raises the possibility that these structures might be key elements in the elusive magnetic sensor system. For the elemental analysis inside materials, x-ray fluorescence method (Synchrotron radiation) is one of the most powerful techniques. BL4A beam line of Photo factory of KEK at Tsukuba was used for analysis of the otolith. Comparing the compositions of the three different kinds of otolith among several species of sea fishes and birds, we found that the saccular and utricular otolith rarely contain detectable levels of Fe (iron), but that Fe is present in significant quantities in the lagenal otolith of the birds. The lagenal otolith is tiny crystal that contains magnetic elements and is sensitively displaced by imposed magnetic fields, providing the animal with geomagnetic sensory input, from which the brain would infer navigational information. Behavioral experiments of the homing abilities of the pigeons involving sectioning the lagenal nerves and the magnetic interfere to their lagena were done using 30 controlled birds and 21 treated birds from the same loft of the racing pigeons. The result of homing test of the control and treated pigeons clearly indicates the magnetic influence and lagenal function to pigeon's navigation ability, and the treated pigeons were either lost or significantly delayed, while the controls returned within 30 minutes after the release. Thus the birds' lagena is unique organ, and it may be concluded that the lagena is a key element to magnetic sensory system for birds. (author)

  18. Restricted fish feeding reduces cod otolith opacity

    DEFF Research Database (Denmark)

    Høie, H.; Folkvord, A.; Mosegaard, Henrik;

    2008-01-01

    The purpose of this work was to examine the effect of reduced feeding and constant temperature on cod otolith opacity. Three groups of juvenile cod were given restricted food rations at different times for 4 months, resulting in depressed somatic growth. Otolith opacity was measured on pictures...... in otolith opacity were found between individual fish both within groups and between groups. In two of the three groups significantly more translucent otolith material was deposited in response to reduced feeding. Our results show that variations in feeding and hence fish growth resulted in variation...

  19. Decreased otolith-mediated vestibular response in 25 astronauts induced by long-duration spaceflight.

    Science.gov (United States)

    Hallgren, Emma; Kornilova, Ludmila; Fransen, Erik; Glukhikh, Dmitrii; Moore, Steven T; Clément, Gilles; Van Ombergen, Angelique; MacDougall, Hamish; Naumov, Ivan; Wuyts, Floris L

    2016-06-01

    The information coming from the vestibular otolith organs is important for the brain when reflexively making appropriate visual and spinal corrections to maintain balance. Symptoms related to failed balance control and navigation are commonly observed in astronauts returning from space. To investigate the effect of microgravity exposure on the otoliths, we studied the otolith-mediated responses elicited by centrifugation in a group of 25 astronauts before and after 6 mo of spaceflight. Ocular counterrolling (OCR) is an otolith-driven reflex that is sensitive to head tilt with regard to gravity and tilts of the gravito-inertial acceleration vector during centrifugation. When comparing pre- and postflight OCR, we found a statistically significant decrease of the OCR response upon return. Nine days after return, the OCR was back at preflight level, indicating a full recovery. Our large study sample allows for more general physiological conclusions about the effect of prolonged microgravity on the otolith system. A deconditioned otolith system is thought to be the cause of several of the negative effects seen in returning astronauts, such as spatial disorientation and orthostatic intolerance. This knowledge should be taken into account for future long-term space missions. PMID:27009158

  20. Ultrastructural aspects of otoliths and sensory epithelia of fish inner ear exposed to hypergravity

    Science.gov (United States)

    Ibsch, M.; Nindl, G.; Anken, R. H.; Körtje, K. H.; Rahmann, H.

    The present electron microscopical investigations were directed to the question, whether alterations in the gravitational force might induce structural changes in the morphology of otoliths or/and inner ear sensory epithelia of developing and adult swordtail fish (Xiphophorus helleri) that had been kept either under long-term moderate hypergravity (8 days; 3g) or under short-time extreme hypergravity (10 minutes up to 9g). The otoliths of adult and neonate swordtail fish were investigated by means of scanning electron microscopy (SEM). Macular epithelia of adult fish were examined both by SEM and transmission electron microscopy (TEM). The saccular otoliths (sagittae) of normally hatched adult fish revealed an enormous inter- (and even intra-; i.e. left vs. right) individual diversity in shape and size, whereas the otoliths of utricles (lapilli) and lagenae (asterisci) seemed to be more constant regarding morphological parameters. The structural diversity of juvenile otoliths was found to be less prominent as compared to the adults, differing from the latter regarding their peculiar crystalline morphology. Qualitative differences in the fine structure (SEM) of otoliths taken from adult and larval animals kept under 3g in comparison to 1g controls could not be observed. The SEM and TEM investigations of sensory epithelia also did not reveal any effects due to 3g stimulation. Even extreme hypergravity (more than 7g) for 10 minutes did not result in distinct pathological changes.

  1. Otolithic information is required for homing in the mouse.

    Science.gov (United States)

    Yoder, Ryan M; Goebel, Elizabeth A; Köppen, Jenny R; Blankenship, Philip A; Blackwell, Ashley A; Wallace, Douglas G

    2015-08-01

    Navigation and the underlying brain signals are influenced by various allothetic and idiothetic cues, depending on environmental conditions and task demands. Visual landmarks typically control navigation in familiar environments but, in the absence of landmarks, self-movement cues are able to guide navigation relatively accurately. These self-movement cues include signals from the vestibular system, and may originate in the semicircular canals or otolith organs. Here, we tested the otolithic contribution to navigation on a food-hoarding task in darkness and in light. The dark test prevented the use of visual cues and thus favored the use of self-movement information, whereas the light test allowed the use of both visual and non-visual cues. In darkness, tilted mice made shorter-duration stops during the outward journey, and made more circuitous homeward journeys than control mice; heading error, trip duration, and peak error were greater for tilted mice than for controls. In light, tilted mice also showed more circuitous homeward trips, but appeared to correct for errors during the journey; heading error, trip duration, and peak error were similar between groups. These results suggest that signals from the otolith organs are necessary for accurate homing performance in mice, with the greatest contribution in non-visual environments. PMID:25565056

  2. Alternative method of removing otoliths from sturgeon

    Science.gov (United States)

    Chalupnicki, Marc A.; Dittman, Dawn E.

    2016-01-01

    Extracting the otoliths (ear bones) from fish that have very thick skulls can be difficult and very time consuming. The common practice of making a transverse vertical incision on the top of the skull with a hand or electrical saw may damage the otolith if not performed correctly. Sturgeons (Acipenseridae) are one family in particular that have a very large and thick skull. A new laboratory method entering the brain cavity from the ventral side of the fish to expose the otoliths was easier than other otolith extraction methods found in the literature. Methods reviewed in the literature are designed for the field and are more efficient at processing large quantities of fish quickly. However, this new technique was designed to be more suited for a laboratory setting when time is not pressing and successful extraction from each specimen is critical. The success of finding and removing otoliths using this technique is very high and does not compromise the structure in any manner. This alternative technique is applicable to other similar fish species for extracting the otoliths.

  3. Factors determining δ13C and δ18O fractionation in aragonitic otoliths of marine fish

    Science.gov (United States)

    Thorrold, Simon R.; Campana, Steven E.; Jones, Cynthia M.; Swart, Peter K.

    1997-07-01

    Fish otoliths are aragonitic accretions located within the inner ear of teleost fish. The acellular nature of otoliths, along with taxon-specific shapes, chronological growth increments, and abundance in the fossil record suggest that the stable isotope chemistry of these structures may be unique recorders of environmental conditions experienced by fish in both modern and ancient water masses. To assess the factors determining δ 13C and δ 18O fractionation in fish otoliths, we reared Atlantic croaker ( Micropogonias undulatus) larvae under controlled environmental conditions. Metabolic effects apparently generated large isotopic disequilibria in the δ 13C values of M. undulatus otoliths. We found evidence of a negative regression between δ 13C- carbonate-δ 13C water (δ 13C) and temperature: δ 13C = -1.78 - 0.18 T °C However, this relationship was aliased to a degree by a positive correlation between δ 13C and somatic growth and otolith precipitation rates. Oxygen isotopes were deposited close to equilibrium with the ambient water. The relationship between temperature and the 18O/ 16O fractionation factor (α) was determined empirically to be: 1000 ln α = 18.56(10 3T K -1) - 32.54 The fractionation factor was not affected by either otolith precipitation or fish growth rates. Reconstruction of water temperature histories should, therefore, be possible from the δ 18O values of M. undulatus otoliths with a precision of 1°C, providing the δ 18O of the ambient water can be estimated.

  4. Fish otolith growth in 1g and 3g depends on the gravity vector.

    Science.gov (United States)

    Anken, R H; Werner, K; Breuer, J; Rahmann, H

    2000-01-01

    Size and asymmetry (size difference between the left and the right side) as well as calcium (Ca) content of inner ear otoliths of larval cichlid fish Oreochromis mossambicus were determined after a long-term stay at hypergravity conditions (3g; centrifuge). Both utricular and saccular otoliths (lapilli and sagittae, respectively) were significantly smaller after hyper-g exposure as compared to parallely raised 1g-control specimens and the absolute amount of otolith-Ca was diminished. The asymmetry of sagittae was significantly increased in the experimental animals, whereas the respective asymmetry concerning lapilli was markedly decreased. In the course of another experiment larvae were raised in aquarium hatch baskets, from which one was placed directly above aeration equipment which resulted in random water circulation shifting the fish around ("shifted" specimens). The lapillar asymmetry of the "stationary" specimens showed a highly significant increase during early development when larvae were forced to lay on their sides due to their prominent yolk-sacs. In later developmental stages, when they began to swim freely, a dramatic decrease in lapillar asymmetry was apparent. Taken together with own previous findings according to which otolith growth stops after vestibular nerve transaction, the results presented here suggest that the growth and the development of bilateral asymmetry of otoliths is guided by the environmental gravity vector, obviously involving a feedback loop between the brain and the inner ear. PMID:11542852

  5. Inner Ear Otolith Growth in larval Fish after Development at simulated Microgravity

    Science.gov (United States)

    Baur, U.; Hilbig, R.; Anken, R.

    It has been shown earlier that hypergravity slows down inner ear otolith growth in developing fish via a down-regulation of carbonic anhydrase reactivity as an adaptation towards altered environmental gravity We were thus prompted to elucidate whether clinorotation would possibly yield opposite effects Therefore larval siblings of cichlid fish Oreochromis mossambicus were housed in a submersed two-dimensional clinostat Two tubes with different diameters were used 10 5 mm large tube LT and 3 5 mm small tube ST experimental time-span 10 and 7 days respectively After the experiments otoliths were dissected and their size area grown during the experiments was determined planimetrically In case of the LT-clinorotated fish both utricular and saccular otoliths lapilli and sagittae respectively were significantly smaller than those of the 1g-controls In contrast ST-maintenance resulted in significantly larger otoliths lapilli only no statistical significant difference regarding sagittae observed The results from LT-clinorotation therefore indicate that the animals had in fact received hypergravity whereas the ST-data are to be interpreted as being effected by simulated microgravity conditions In conclusion otolith growth is affected by the gravitational vector in a dose-dependent manner Acknowledgement This work was financially supported by the German Aerospace Center DLR FKZ 50 WB 9997

  6. Estimating population age structure using otolith morphometrics

    DEFF Research Database (Denmark)

    Doering-Arjes, P.; Cardinale, M.; Mosegaard, Henrik

    2008-01-01

    known-age fish individuals. Here we used known-age Atlantic cod (Gadus morhua) from the Faroe Bank and Faroe Plateau stocks. Cod populations usually show quite large variation in growth rates and otolith shape. We showed that including otolith morphometrics into ageing processes has the potential...... populations. The intercalibration method was successful but generalization from one stock to another remains problematic. The development of an otolith growth model is needed for generalization if an operational method for different populations is required in the future....... to make ageing objective, accurate, and fast. Calibration analysis indicated that a known-age sample from the same population and environment is needed to obtain robust calibration; using a sample from a different stock more than doubles the error rate, even in the case of genetically highly related...

  7. Development of the otolith organs and semicircular canals in the Japanese red-bellied newt, Cynops pyrrhogaster

    Science.gov (United States)

    Wiederhold, M. L.; Yamashita, M.; Larsen, K. A.; Batten, J. S.; Koike, H.; Asashima, M.

    1995-01-01

    The sequence in which the otoliths and semicircular canals and their associated sensory epithelia appear and develop in the newt are described. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos from stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. A single otolith is first seen in stage 33 embryos (approximately 9 days old); this splits into separate utricular and saccular otoliths at stage 40 (13 days). The lateral semicircular canal is the first to appear, at stage 41 (14 days). The anterior and posterior canals appear approximately one week later and the vestibular apparatus is essentially fully formed at stage 58 (approximately 5 weeks). The data reported here will serve as ground-based controls for fertilized newt eggs flown on the International Microgravity Laboratory-2 Space Shuttle flight, to investigate the influence of microgravity on the development of the gravity-sensing organs.

  8. Ontogenetic development of otoliths in Alligator Gar

    Science.gov (United States)

    Long, James M.; Snow, Richard A.

    2016-01-01

    The Alligator Gar Atractosteus spatula is a species of conservation concern throughout its range, and better definition of otoliths during early development would aid understanding its life history and ecology. We conducted X-ray computed tomography scans, scanning electron microscopy, and light microscopy to examine the three pairs of otoliths and how they developed over time in relation to fish size and age. The sagittae are the largest, possessing distinct dorsal and ventral lobes covered with small otoconia concentrated in the sulcul region. The sagittae exhibited allometric growth, increasing more rapidly in the ventral lobe than in the dorsal. The asterisci were smaller and also exhibited small otoconia on their surface, but much less than the sagittae. The lapilli were oriented laterally, in contrast to the sagittae and asterisci, which were oriented vertically, with a hump on the dorsum and very large otoconia on the lateral surface that appeared to fuse into the main otolith as the fish grew. Based on size measurements and ring counts in all three pairs of otoliths from 101 known-age Alligator Gar sampled weekly through 91 d after hatch, we developed regression models to examine otolith growth and predict age. All relationships were significant and highly explanatory, but the strongest relationships were between otolith and fish size (for measurements from sagittae) and for age predictions from the lapillus. Age prediction models all resulted in a slope near unity, indicating that ring deposition occurred approximately daily. The first ring in sagittae and lapilli corresponded to swim-up, whereas the first ring formed in asterisci approximately 8 d after swim-up. These results fill a gap in knowledge and can aid understanding of evolutionary processes as well as provide useful information for management and conservation.

  9. The OTOLITH Experiment - Assessment of Otolith Function During Postflight Re-adaption

    Science.gov (United States)

    Clarke, A. H.; Wood, S. J.; Schoenfeld, U.

    2010-01-01

    The ongoing "Otolith" experiment is designed to comprehensively assess the otolith function during the re-adaptation phase after spaceflight. The novel protocol includes unilateral testing of each of the two otolith organs the utricle and the saccule. To assess utricle function, the otolith-ocular response (OOR) and the subjective visual vertical (SVV) are measured during unilateral centrifugation, which permits independent stimulation of the right and left ear. Measurement of the unilateral otolith-ocular response (uOOR) yields information on the response behaviour of the right and left peripheral utricles, whereas the SVV reflects the behaviour of the entire pathway from the peripheral otolith receptors to the vestibular cortex. Thus, by comparative evaluation of the results from the two tests, the degree of peripheral versus central adaptation during the post-flight period can be determined. To assess unilateral saccule function, vestibular evoked myogenic potentials (VEMP) are recorded. Since the saccules are predominantly aligned to gravity, and interplay with the antigravity muscles, it is hypothesised that these potentials shall be altered after spaceflight. To date the study has been conducted with 5 of a planned 8 short-flight Shuttle astronauts. Preliminary results will be discussed together with those from clinical studies of dizziness patients, where the same test protocol is employed. ACKNOWLEDGEMENT This work is supported by the German Aerospace Center (Grant DLR W130729) and is conducted under the auspices of ESA, in cooperation with NASA.

  10. Can analysis of Platichthys flesus otoliths provide relevant data on historical metal pollution in estuaries? Experimental and in situ approaches.

    Science.gov (United States)

    Selleslagh, Jonathan; Echard, Aurélie; Pécheyran, Christophe; Baudrimont, Magalie; Lobry, Jérémy; Daverat, Françoise

    2016-07-01

    Despite recent efforts to manage them more efficiently, estuaries are natural sinks for a wide range of metal contaminants, many of which accumulate at potentially toxic concentrations for fish populations, posing a threat to recruitment and stocks. While analysis of metal concentrations in soft tissue and water samples calls for continuous and long-term sampling operations, the use of otoliths to study metal pollution may be one way of providing a historical record of pollutant exposure. In this study, we examine the potential use of otoliths as natural tracers of metal contamination. A "cocktail" of different metals (Cd, Pb and Ni) was used to test bio-accumulation in otoliths and tissue (liver, kidney, muscle and gills) extracted from juvenile flounder (Platichthys flesus). Assessment took place under controlled conditions over a three month period, with water exposure concentrations increasing every 3weeks. The concentrations used were natural (T1), X5 (T2), X10 (T3), and null (T4). Chemical analyses were carried out using an inductively coupled plasma optical emission spectrometer ICP-OES and atomic absorption spectrometer AAS for water and tissue, while otolith microchemistry analyses were performed using a femtosecond laser ablation-high resolution inductively coupled plasma mass spectrometer (fsLA-ICP-MS-HR). Significant differences between control and exposed individuals, as well as an increase in metal concentrations according to exposure level, were observed in all tissues except in muscle tissue. Significant increases in Pb were also detected in contaminated fish otoliths compared with control specimens, with the highest concentrations occurring in T3. Cartographies of Pb distribution in otoliths of both control and contaminated fish only showed high concentrations of Pb at the edge of contaminated fish otoliths, indicating an accumulation of metal during the experiment. Although the relationships between exposure level and Pb concentration in otoliths

  11. Otoliths in continental shelf and slope surficial sediments off Saurashtra, Arabian Sea, India and their significance

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; John; Rana, R.S.

    Otoliths are a viable and underutlized paleoceanographic tool. In India a considerable amount of work has been done on otoliths of the fresh water fishes, however no significant report is available for marine otoliths. In the present study, about 89...

  12. Otolith-Canal Convergence In Vestibular Nuclei Neurons

    Science.gov (United States)

    Dickman, J. David; Si, Xiao-Hong

    2002-01-01

    The current final report covers the period from June 1, 1999 to May 31, 2002. The primary objective of the investigation was to determine how information regarding head movements and head position relative to gravity is received and processed by central vestibular nuclei neurons in the brainstem. Specialized receptors in the vestibular labyrinths of the inner ear function to detect angular and linear accelerations of the head, with receptors located in the semicircular canals transducing rotational head movements and receptors located in the otolith organs transducing changes in head position relative to gravity or linear accelerations of the head. The information from these different receptors is then transmitted to central vestibular nuclei neurons which process the input signals, then project the appropriate output information to the eye, head, and body musculature motor neurons to control compensatory reflexes. Although a number of studies have reported on the responsiveness of vestibular nuclei neurons, it has not yet been possible to determine precisely how these cells combine the information from the different angular and linear acceleration receptors into a correct neural output signal. In the present project, rotational and linear motion stimuli were separately delivered while recording responses from vestibular nuclei neurons that were characterized according to direct input from the labyrinth and eye movement sensitivity. Responses from neurons receiving convergent input from the semicircular canals and otolith organs were quantified and compared to non-convergent neurons.

  13. Not All Inner Ears are the Same: Otolith Matrix Proteins in the Inner Ear of Sub-Adult Cichlid Fish, Oreochromis Mossambicus, Reveal Insights Into the Biomineralization Process.

    Science.gov (United States)

    Weigele, Jochen; Franz-Odendaal, Tamara A; Hilbig, Reinhard

    2016-02-01

    The fish ear stones (otoliths) consist mainly of calcium carbonate and have lower amounts of a proteinous matrix. This matrix consists of macromolecules, which directly control the biomineralization process. We analyzed the composition of this proteinous matrix by mass spectrometry in a shotgun approach. For this purpose, an enhanced protein purification technique was developed that excludes any potential contamination of proteins from body fluids. Using this method we identified eight proteins in the inner ear of Oreochromis mossambicus. These include the common otolith matrix proteins (OMP-1, otolin-1, neuroserpin, SPARC and otoconin), and three proteins (alpha tectorin, otogelin and transferrin) not previously localized to the otoliths. Moreover, we were able to exclude the occurrence of two matrix proteins (starmaker and pre-cerebellin-like protein) known from other fish species. In further analyses, we show that the absence of the OMP starmaker corresponds to calcitic otoliths and that pre-cerebellin-like protein is not present at any stage during the development of the otoliths of the inner ear. This study shows O. mossambicus does not have all of the known otolith proteins indicating that the matrix proteins in the inner ear of fish are not the same across species. Further functional studies of the novel proteins we identified during otolith development are required.

  14. Argon laser irradiation of the otolithic organ

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, T.; Nomura, Y.; Young, Y.H.; Hara, M. (Univ. of Tokyo (Japan))

    1990-12-01

    An argon laser was used to irradiate the otolithic organs of guinea pigs and cynomolgus monkeys. After stapedectomy, the argon laser (1.5 W x 0.5 sec/shot) irradiated the utricle or saccule without touching the sensory organs. The stapes was replaced over the oval window after irradiation. The animals used for acute observation were killed immediately for morphologic studies; those used for long-term observation were kept alive for 2, 4, or 10 weeks. Acute observation revealed that sensory and supporting cells were elevated from the basement membrane only in the irradiated area. No rupture of the membranous labyrinth was observed. Long-term observation revealed that the otolith of the macula utriculi had disappeared in 2-week specimens. The entire macula utricili had disappeared in 10-week specimens. No morphologic changes were observed in cochlea, semicircular canals, or membranous labyrinth. The saccule showed similar changes.

  15. Aberrant otoliths in juvenile flounder Platichthys flesus (L.

    Directory of Open Access Journals (Sweden)

    Vanessa Neves

    2015-11-01

    Full Text Available Anomalous otolith formation has been reported in freshwater and marine fish species. The prevailing anomaly is the deposition of vaterite instead of aragonite, resulting in different otolith shape and transparency. In this study we report high occurrence rates of anomalous otoliths in juvenile flounder collected in the river Minho estuary (NW Portugal. Several pairs of otoliths were randomly selected from juvenile fish collected between 2013 and 2015, in two estuarine areas, and visually inspected on both sides for the presence of anomalies. Most anomalies consisted of depressions, projections or holes in different parts of the otolith. Distribution of irregularities was examined in relation to site of collection and fish total length. At the site with higher salinity, most otolith pairs were normal. In contrast, at the tidal freshwater station, 43% of the pairs examined were abnormal. In general, both otoliths were affected but the left one presented more extreme changes. The occurrence of anomalies seems to be related to fish size since these were only found in fish smaller than 7.5 cm. Preliminary morphometric analyses indicate that abnormal otoliths have the same proportions as normal ones, but the former seem heavier, for the same sized fish. It is presently unclear how these anomalies affect fish growth or survival. Raman microspectroscopy was used to determine the mineral phases (i.e. type of CaCO3 polymorph in one normal and one abnormal otolith, revealing crystals of aragonitic-type in both cases. SEM-EDS analysis corroborated Raman results and did not reveal differences in chemical composition between abnormal and normal zones but further studies are needed.

  16. Evaluation of Response Patterns in Somatic and Otolith Features of Laboratory- Reared and Wild Clarias gariepinus Exposed to Industrial Effluent

    Directory of Open Access Journals (Sweden)

    Aina O. Adeogun

    2013-01-01

    Full Text Available This study was aimed at comparing the responses of somatic and otolith features in Clarias gariepinus under chronic exposure conditions to industrial effluents in the laboratory for 60 days and in the wild for 6 months. Fish were collected upstream and downstream bi-monthly from a river receiving composite mixtures of industrial effluent while laboratory-rearedC. gariepinus were exposed to the same effluent mixtures in 60 days static renewal/bioassay using concentrations of 6.11, 3.05 and 2.23%, respectively and control series. A total of 21 variables representing saggital otolith and somatic data from both wild and laboratory fish were subjected to factor analysis. For laboratory reared fish, PC 1 indexed as ‘otolith factor’, PC 2 indexed as ‘condition factor’ and PC 3 indexed as ‘paired fin factor’ accounted for 26.15, 19.01 and 12.55% of the total variance, respectively. For wild fish, otolith factor (PC 1 and condition factor (PC 2 accounted for 38.24 and 22.69% of the variance respectively. The first 3 components and the first 2 components for laboratory and wild fish accounted for more than 50% of total variance in data. Reliability index (Cronbach’s alpha (&alpha>0.70 showed that the ‘otolith factor’ had strong internal consistency and is reliable as a primary and viable index of stress for both laboratory and wild fish. The complementary role of condition factor in stress detection was also highlighted. The emergence of paired features (otolith, pectoral and pelvic fins as sensitive parameters in toxicity responses may be an indication of the onset of asymmetry in these structures.

  17. Shedding light on fish otolith biomineralization using a bioenergetic approach.

    Science.gov (United States)

    Fablet, Ronan; Pecquerie, Laure; de Pontual, Hélène; Høie, Hans; Millner, Richard; Mosegaard, Henrik; Kooijman, Sebastiaan A L M

    2011-01-01

    Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm-following formation provides individual records of the age, the individual history and the natural environment of extinct and living fish species. Such data are critical for ecosystem and fisheries monitoring. They however often lack validation and the poor understanding of biomineralization mechanisms has led to striking examples of misinterpretations and subsequent erroneous conclusions in fish ecology and fisheries management. Here we develop and validate a numerical model of otolith biomineralization. Based on a general bioenergetic theory, it disentangles the complex interplay between metabolic and temperature effects on biomineralization. This model resolves controversial issues and explains poorly understood observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves.

  18. Shedding Light on Fish Otolith Biomineralization Using a Bioenergetic Approach

    Science.gov (United States)

    Fablet, Ronan; Pecquerie, Laure; de Pontual, Hélène; Høie, Hans; Millner, Richard; Mosegaard, Henrik; Kooijman, Sebastiaan A. L. M.

    2011-01-01

    Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm-following formation provides individual records of the age, the individual history and the natural environment of extinct and living fish species. Such data are critical for ecosystem and fisheries monitoring. They however often lack validation and the poor understanding of biomineralization mechanisms has led to striking examples of misinterpretations and subsequent erroneous conclusions in fish ecology and fisheries management. Here we develop and validate a numerical model of otolith biomineralization. Based on a general bioenergetic theory, it disentangles the complex interplay between metabolic and temperature effects on biomineralization. This model resolves controversial issues and explains poorly understood observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves. PMID:22110601

  19. Shedding light on fish otolith biomineralization using a bioenergetic approach.

    Directory of Open Access Journals (Sweden)

    Ronan Fablet

    Full Text Available Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm-following formation provides individual records of the age, the individual history and the natural environment of extinct and living fish species. Such data are critical for ecosystem and fisheries monitoring. They however often lack validation and the poor understanding of biomineralization mechanisms has led to striking examples of misinterpretations and subsequent erroneous conclusions in fish ecology and fisheries management. Here we develop and validate a numerical model of otolith biomineralization. Based on a general bioenergetic theory, it disentangles the complex interplay between metabolic and temperature effects on biomineralization. This model resolves controversial issues and explains poorly understood observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves.

  20. Trace metals and otolith defects in mocha mice.

    Science.gov (United States)

    Rolfsen, R M; Erway, L C

    1984-01-01

    Mocha mice with pigment anomalies of the coat, eyes, and inner ears also have congenital otolith defects, and they exhibit progressive cochlear degeneration. Mocha mice were first reported to exhibit otolith defects comparable to those of pallid mice. Since manganese supplementation is effective in preventing the otolith defects in pallid mice and in pastel mink, we sought to establish whether or not manganese also might be effective in mocha mice. The otolith defects of mocha mice were prevented or reduced by supplementing the pregnant dams with manganese and/or zinc. The mocha mice also exhibited high perinatal mortality that was not reduced by the supplementary metals. Surviving mocha mice have behavioral anomalies associated with their inner ear defects. Preliminary observations of auditory-evoked brainstem responses and of cochlear degeneration in the mocha mice are discussed. PMID:6736600

  1. Lead-Radium Activity Ratios From Otoliths of Regional Bottomfishes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains lead-radium dating of opakapaka (Pristipomoides filamentosus) otoliths from recent and archival collections (1987-2009).

  2. Bio-PIXE marine science. Otoliths and plankton

    Energy Technology Data Exchange (ETDEWEB)

    Malmqvist, K.G.; Buelow, K.; Elfman, M.; Kristiansson, P; Pallon, J.; Shariff, S. [Department of Nuclear Physics, Lund University, Lund (Sweden); Limburg, K.E. [Dept. of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, NY (United States); Karlsson, C. [Department of Marine Sciences, University of Kalmar, Kalmar (Sweden)

    1999-07-01

    Otoliths and phytoplanktons have been investigated using a nuclear microprobe. A brief description of sample preparation and irradiation conditions is given. The results indicate a great potential of the technique in marine sciences. (author)

  3. Shedding light on fish otolith biomineralization using a bioenergetic approach

    DEFF Research Database (Denmark)

    Fablet, R.; Pecquerie, L.; de Pontual, H.;

    2011-01-01

    Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm-following formation provides individual records of the age, the individual history and the natural environment of extinct and living fish species. Such data are critical for ecosys...... simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves...

  4. Pleistocene fish otoliths from the Mediterranean Basin: a synthesis

    OpenAIRE

    Girone, A.; Nolf, D.; Cappetta, H

    2006-01-01

    An overview of upper pPliocene and Pleistocene otolith assemblages is compiled on the basis of both literature data and newly collected material from several sections located mainly in southern Italy. One hundred and five taxa are listed. Additional comments are provided for taxa subject to discussion. The composition and affinities of the Mediterranean Pleistocene otolith associations (consisting mainly of deep sea fishes) is checked against the available data for Pre-Messinian, Pliocene, an...

  5. The role of otolith size in hearing – Insights from cichlid fishes

    Directory of Open Access Journals (Sweden)

    Tanja Schulz-Mirbach

    2015-10-01

    Full Text Available Otolithic end organs in fishes function as accelerometers and are involved in the senses of balance and hearing (e.g. Popper et al. 2005. Otolith mass and shape are likely decisive factors influencing otolith motion, but while it is largely unknown how different shapes affect otolith movement relative to the sensory epithelium (Popper et al. 2005, greater otolith mass is predicted to result in enhanced stimulation of sensory hair cells and improved hearing (Lychakov and Rebane 2005. What few studies exist on this topic, however, yielded contradicting results in that they did or did not find a correlation between increased otolith mass and enhanced hearing (see Kéver et al. 2014. We investigated the relationship between otolith morphology (including 3D-models of otoliths based on high-resolution microCT imaging and otolith weight and hearing abilities in cichlids while comparing three species (Etroplus maculatus, Hemichromis guttatus, Steatocranus tinanti with different swimbladder morphology and hearing abilities (Schulz-Mirbach et al. 2014. We predicted Etroplus maculatus—the species that displays the best hearing sensitivities—to possess larger/heavier otoliths. As swimbladder extensions in this species are connected to the lagena, we further predicted to find heavier lagenar otoliths. Compared to H. guttatus and S. tinanti, E. maculatus showed the heaviest saccular otoliths, while lagenar otoliths were significantly thinner and lighter than in the former two species, apparently contradicting the hypothesis that the lagena and its otolith are primarily involved in improved hearing abilities. Our results support the idea that there is no ‘simple’ relationship between otolith weight, ancilliary auditory structures and hearing abilities. 3D-models of inner ears and otoliths may be ideally suited for future studies modeling complex otolith motion and thus, may provide a better understanding of how otolith morphology contributes to inner

  6. Validation of daily increment formation in otoliths for Gymnocypris selincuoensis in the Tibetan Plateau, China.

    Science.gov (United States)

    Ding, Chengzhi; Chen, Yifeng; He, Dekui; Tao, Juan

    2015-08-01

    Daily increment validation in fish otolith is fundamental to studies on fish otolith microstructure, age determination and life history traits, and thus is critical for species conservation and fishery management. However, it has never been done for Schizothoracine fish, which is the dominant component of fish fauna in the Tibetan Plateau. This study validated the daily increment formation of Gymnocypris selincuoensis, as a representative of Schizothoracine fish, by monitoring the growth of hatchery-reared larvae group and wild-caught post-yolk-sac larvae group under controlled experiments. The results from monitoring the hatchery-reared larvae group showed that sagittae and lapilli were found in yolk-sac larvae, and formed 5-7 days before hatching, but asterisci were not found until 11 days post-hatching. The first increment in sagittae and lapilli was formed in the first day after hatching. The daily periodicity of increment formation was examined and confirmed in sagittae and lapilli of both larvae groups. However, sagittae were better for age determination than lapilli for larvae at earlier days. For larval G. selincuoensis older than 50 days, lapilli were the only otolith pair suitable for larvae daily age determination. This study validated the daily increment formation in Schizothoracine fish for the first time has primary implications to other fishes from this subfamily. PMID:26380660

  7. Development of utricular otoliths, but not saccular otoliths, is necessary for vestibular function and survival in zebrafish

    Science.gov (United States)

    Riley, B. B.; Moorman, S. J.

    2000-01-01

    We have been studying the consequences of embryonic vestibular dysfunction caused by the monolith (mnl) mutation in zebrafish. mnl is a dominant mutation that specifically inhibits formation of utricular otoliths. However, briefly immobilizing mnl/mnl embryos in agarose with the otic vesicle orientated at certain angles selectively induces or prevents formation of utricular and/or saccular otoliths. With this noninvasive technique, we generated six phenotypic classes of mnl/mnl mutants, designated S-S, U-U, U-S, S-US, U-US, and US-US, depending on which otoliths are present on each side (U, utricular otolith; S, saccular otolith). All mnl/mnl larvae survived through day 10 of development. Thereafter, S-S larvae showed a rapid decline, probably because of starvation, and none survived to adulthood. Survival rates in all other classes of mnl/mnl larvae (those having at least one utricular otolith) were close to normal. The presence or absence of utricular otoliths also correlated with vestibular function during early larval development, as measured by three criteria: First, unlike wild-type larvae, S-S mutant larvae showed almost no detectable counter-rotation of the eyes when tilted tail up or tail down. Second, 95% of S-S mutant larvae never acquired the ability to maintain a balanced dorsal-up posture. Third, although most wild-type larvae responded to gentle prodding by swimming in a straight line, S-S larvae responded by swimming in rapid circles, showing sudden and frequent changes in direction ("zigzagging"), and/or rolling and spiraling. All other phenotypic classes of mnl/mnl larvae behaved normally in these assays. These data demonstrate that bilateral loss of utricular otoliths disrupts the ability to sense gravity, severely impairs balance and motor coordination, and is invariably lethal. The presence of a utricular otolith in at least one inner ear is necessary and sufficient for vestibular function and survival. In contrast, saccular otoliths are

  8. Otolithic organ function in patients with profound sensorineural hearing loss

    Institute of Scientific and Technical Information of China (English)

    Yujuan Zhou; Yongzhen Wu; Jing Wang

    2016-01-01

    Profound sensorineural hearing loss (PSHL) is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous membranous structure and similar receptor cell ultrastructures, the cochlea and vestibule may be susceptible to the same harmful factors. Disorders of the inner ear may result in a variety of manifestations, including vertigo, spatial disorientation, blurred vision, impaired articulation, and hearing impairment. Considering the diversity of clinical symptoms associated with PSHL with otolithic dysfunction, it may be frequently misdiagnosed, and objective means of testing the function of otolithic organs should be recommended for hearing-impaired patients. Vestibular-evoked myogenic potentials (VEMPs) via air-conducted sound are of great importance for the diagnosis of otolithic function. Hearing devices such as cochlear implants are commonly accepted treatments for PSHL, and early identification and treatment of vestibular disorders may increase the success rate of cochlear implantation. Therefore, it is necessary to increase awareness of otolithic functional states in patients with PSHL.

  9. Optical manipulation for optogenetics: otoliths manipulation in zebrafish (Conference Presentation)

    Science.gov (United States)

    Favre-Bulle, Itia A.; Scott, Ethan; Rubinsztein-Dunlop, Halina

    2016-03-01

    Otoliths play an important role in Zebrafish in terms of hearing and sense of balance. Many studies have been conducted to understand its structure and function, however the encoding of its movement in the brain remains unknown. Here we developed a noninvasive system capable of manipulating the otolith using optical trapping while we image its behavioral response and brain activity. We'll also present our tools for behavioral response detection and brain activity mapping. Acceleration is sensed through movements of the otoliths in the inner ear. Because experimental manipulations involve movements, electrophysiology and fluorescence microscopy are difficult. As a result, the neural codes underlying acceleration sensation are poorly understood. We have developed a technique for optically trapping otoliths, allowing us to simulate acceleration in stationary larval zebrafish. By applying forces to the otoliths, we can elicit behavioral responses consistent with compensation for perceived acceleration. Since the animal is stationary, we can use calcium imaging in these animals' brains to identify the functional circuits responsible for mediating responses to acceleration in natural settings.

  10. Metal contents in tench otoliths: relationships to the aquatic environment.

    Science.gov (United States)

    Adami, G; Miletić, M; Siviero, P; Barbieri, P; Reisenhofer, E

    2001-01-01

    A monitoring of the quality of waters was attempted determining metal accumulation in target organs as otoliths of freshwater fish. Tenchs of age ranging between 2 and 10 years were sampled in three different canals receiving wastewater from industrial, agricultural and urban activities. Metal contents were determined in both lapilli and asterisci otoliths, using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Analytical data are reported for minor metals and for some trace metals. Al, Fe and Zn have contents depending on the environment where the fish has lived, while Na, K, Ca and Sr contents are insensitive to the different aquatic habitat. Considering the two types of otolith separately, lapilli display a different affinity for trace metals (Al, Fe and Zn), while in asterisci this affinity is matched only for zinc. The high affinity of zinc for both types of otoliths suggests using this metal for discriminating the fresh waters by checking its accumulation in otoliths, as well as correlating this accumulation with age of the fish: a negative power curve equation is proposed. Since highest concentrations are found in individuals of 2-3 yr., it is advisable to use this fish for such environmental studies. PMID:11554178

  11. Bisphenol A induces otolith malformations during vertebrate embryogenesis

    Directory of Open Access Journals (Sweden)

    Demeneix Barbara

    2011-01-01

    Full Text Available Abstract Background The plastic monomer and plasticizer bisphenol A (BPA, used for manufacturing polycarbonate plastic and epoxy resins, is produced at over 2.5 million metric tons per year. Concerns have been raised that BPA acts as an endocrine disruptor on both developmental and reproductive processes and a large body of evidence suggests that BPA interferes with estrogen and thyroid hormone signaling. Here, we investigated BPA effects during embryonic development using the zebrafish and Xenopus models. Results We report that BPA exposure leads to severe malformations of the otic vesicle. In zebrafish and in Xenopus embryos, exposure to BPA during the first developmental day resulted in dose-dependent defects in otolith formation. Defects included aggregation, multiplication and occasionally failure to form otoliths. As no effects on otolith development were seen with exposure to micromolar concentrations of thyroid hormone, 17-ß-estradiol or of the estrogen receptor antagonist ICI 182,780 we conclude that the effects of BPA are independent of estrogen receptors or thyroid-hormone receptors. Na+/K+ ATPases are crucial for otolith formation in zebrafish. Pharmacological inhibition of the major Na+/K+ ATPase with ouabain can rescue the BPA-induced otolith phenotype. Conclusions The data suggest that the spectrum of BPA action is wider than previously expected and argue for a systematic survey of the developmental effects of this endocrine disruptor.

  12. Adaptive plasticity in the otolith-ocular reflex.

    Science.gov (United States)

    Koizuka, Izumi

    2003-02-01

    This review focuses on the plasticity in the vestibulo-ocular reflex (VOR), especially in the otolith-ocular reflex (OOR). The VOR is a mechanism for the production of rapid compensatory eye movements during head movements. The VOR is under adaptive control which corrects VOR performance when visual-vestibular mismatch arises during head movements. It has been demonstrated that chronic exposure to certain visual environments, those generated by magnifying lenses and reversing prisms, alter the gain and phase of VOR in the dark in numerous species. Most experiments concerning such modification of the VOR have used semicircular canal stimulation. The VOR consists of the semicircular-ocular reflex (ScOR) and the OOR. There are few results regarding the relationship between the gain of the ScOR and the OOR. This review summarizes the studies on plasticity in the OOR. In addition, the difficulty in evaluating the OOR using current conventional methods including earth horizontal axis (EHA) rotation, off-vertical axis rotation (OVAR) and linear sled, is discussed. We believe that the ScOR and the OOR share common neural pathways in such a way that a change in the synaptic efficacy of one pathway is accompanied by a change in the other.

  13. The cerebellar nodulus/uvula integrates otolith signals for the translational vestibulo-ocular reflex.

    Directory of Open Access Journals (Sweden)

    Mark F Walker

    Full Text Available BACKGROUND: The otolith-driven translational vestibulo-ocular reflex (tVOR generates compensatory eye movements to linear head accelerations. Studies in humans indicate that the cerebellum plays a critical role in the neural control of the tVOR, but little is known about mechanisms of this control or the functions of specific cerebellar structures. Here, we chose to investigate the contribution of the nodulus and uvula, which have been shown by prior studies to be involved in the processing of otolith signals in other contexts. METHODOLOGY/PRINCIPAL FINDINGS: We recorded eye movements in two rhesus monkeys during steps of linear motion along the interaural axis before and after surgical lesions of the cerebellar uvula and nodulus. The lesions strikingly reduced eye velocity during constant-velocity motion but had only a small effect on the response to initial head acceleration. We fit eye velocity to a linear combination of head acceleration and velocity and to a dynamic mathematical model of the tVOR that incorporated a specific integrator of head acceleration. Based on parameter optimization, the lesion decreased the gain of the pathway containing this new integrator by 62%. The component of eye velocity that depended directly on head acceleration changed little (gain decrease of 13%. In a final set of simulations, we compared our data to the predictions of previous models of the tVOR, none of which could account for our experimental findings. CONCLUSIONS/ SIGNIFICANCE: Our results provide new and important information regarding the neural control of the tVOR. Specifically, they point to a key role for the cerebellar nodulus and uvula in the mathematical integration of afferent linear head acceleration signals. This function is likely to be critical not only for the tVOR but also for the otolith-mediated reflexes that control posture and balance.

  14. Otoliths as an integral part in fossil fish taxonomy

    Directory of Open Access Journals (Sweden)

    Christoph Gierl

    2015-11-01

    Full Text Available Otoliths are small structures in the skull of fishes. They are responsible for hearing and orientation in the 3-dimensional space. They also hold valuable information regarding the taxonomy. Their outline, the shape of the sulcus and other features allow the determination of a fish even to the species level. A lot of fossil species are solely based on otoliths because of their good chance of preservation. Gobies are in this case no different. An additional challenge in gobies is their high similarity between species concerning the preservable parts. Fossil skeletons that are 20 Million years old can show only few differences compared to recent gobies. These features are often hardly recognizable due to their preservation. As a consequence many fossil gobies have been assigned to the genus Gobius sensu lato. Examples are two gobies from the Miocene of Southern Germany. They have a unique combination of characters (six branchiostegals, palatine resembling a “T”, no entopterygoid that allows the rectification of a new fossil genus but the two species are hardly distinguishable based only on the skeleton. The key hints in having two species are the otoliths. They show slight but consistent differences in their outline. This shows that otoliths can be a key feature in species identification. They should also be taken into consideration by recent fish species. Not to mention their possible phylogenetic potential that remains to be explored.

  15. Suitability of otolith microchemistry for stock separation of Baltic cod

    DEFF Research Database (Denmark)

    Heidemann, F; Marohn, L; Hinrichsen, HH;

    2012-01-01

    the Baltic Sea was examined using laser ablation-ICPMS. The capacity to distinguish individuals from different Baltic Sea stocks and from the adjacent North Sea stock based on incoporation of stock-specific elemental fingerprints along otolith growth axes was investigated. It was further tested if different...

  16. A review on otolith models in human perception.

    Science.gov (United States)

    Asadi, Houshyar; Mohamed, Shady; Lim, Chee Peng; Nahavandi, Saeid

    2016-08-01

    The vestibular system, which consists of semicircular canals and otolith, are the main sensors mammals use to perceive rotational and linear motions. Identifying the most suitable and consistent mathematical model of the vestibular system is important for research related to driving perception. An appropriate vestibular model is essential for implementation of the Motion Cueing Algorithm (MCA) for motion simulation purposes, because the quality of the MCA is directly dependent on the vestibular model used. In this review, the history and development process of otolith models are presented and analyzed. The otolith organs can detect linear acceleration and transmit information about sensed applied specific forces on the human body. The main purpose of this review is to determine the appropriate otolith models that agree with theoretical analyses and experimental results as well as provide reliable estimation for the vestibular system functions. Formulating and selecting the most appropriate mathematical model of the vestibular system is important to ensure successful human perception modelling and simulation when implementing the model into the MCA for motion analysis.

  17. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

    Science.gov (United States)

    Smith, William E.; Kwak, Thomas J.

    2014-01-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  18. Magnetic resonance imaging of the saccular otolithic mass.

    OpenAIRE

    Sbarbati, A; Leclercq, F; Antonakis, K; Osculati, F.

    1992-01-01

    The frog's inner ear was studied in vivo by high spatial resolution magnetic resonance imaging at 7 Tesla. The vestibule, the internal acoustic meatus, and the auditory tube have been identified. The large otolithic mass contained in the vestibule showed a virtual absence of magnetic resonance signal probably due to its composition of closely packed otoconia.

  19. Otolith geochemistry does not reflect dispersal history of clownfish larvae

    KAUST Repository

    Berumen, Michael L.

    2010-07-01

    Natural geochemical signatures in calcified structures are commonly employed to retrospectively estimate dispersal pathways of larval fish and invertebrates. However, the accuracy of the approach is generally untested due to the absence of individuals with known dispersal histories. We used genetic parentage analysis (genotyping) to divide 110 new recruits of the orange clownfish, Amphiprion percula, from Kimbe Island, Papua New Guinea, into two groups: "self-recruiters" spawned by parents on Kimbe Island and "immigrants" that had dispersed from distant reefs (>10 km away). Analysis of daily increments in sagittal otoliths found no significant difference in PLDs or otolith growth rates between self-recruiting and immigrant larvae. We also quantified otolith Sr/Ca and Ba/Ca ratios during the larval phase using laser ablation inductively coupled plasma mass spectrometry. Again, we found no significant differences in larval profiles of either element between self-recruits and immigrants. Our results highlight the need for caution when interpreting otolith dispersal histories based on natural geochemical tags in the absence of water chemistry data or known-origin larvae with which to test the discriminatory ability of natural tags. © 2010 Springer-Verlag.

  20. A review on otolith models in human perception.

    Science.gov (United States)

    Asadi, Houshyar; Mohamed, Shady; Lim, Chee Peng; Nahavandi, Saeid

    2016-08-01

    The vestibular system, which consists of semicircular canals and otolith, are the main sensors mammals use to perceive rotational and linear motions. Identifying the most suitable and consistent mathematical model of the vestibular system is important for research related to driving perception. An appropriate vestibular model is essential for implementation of the Motion Cueing Algorithm (MCA) for motion simulation purposes, because the quality of the MCA is directly dependent on the vestibular model used. In this review, the history and development process of otolith models are presented and analyzed. The otolith organs can detect linear acceleration and transmit information about sensed applied specific forces on the human body. The main purpose of this review is to determine the appropriate otolith models that agree with theoretical analyses and experimental results as well as provide reliable estimation for the vestibular system functions. Formulating and selecting the most appropriate mathematical model of the vestibular system is important to ensure successful human perception modelling and simulation when implementing the model into the MCA for motion analysis. PMID:27091675

  1. Otolith geochemistry does not reflect dispersal history of clownfish larvae

    Science.gov (United States)

    Berumen, M. L.; Walsh, H. J.; Raventos, N.; Planes, S.; Jones, G. P.; Starczak, V.; Thorrold, S. R.

    2010-12-01

    Natural geochemical signatures in calcified structures are commonly employed to retrospectively estimate dispersal pathways of larval fish and invertebrates. However, the accuracy of the approach is generally untested due to the absence of individuals with known dispersal histories. We used genetic parentage analysis (genotyping) to divide 110 new recruits of the orange clownfish, Amphiprion percula, from Kimbe Island, Papua New Guinea, into two groups: “self-recruiters” spawned by parents on Kimbe Island and “immigrants” that had dispersed from distant reefs (>10 km away). Analysis of daily increments in sagittal otoliths found no significant difference in PLDs or otolith growth rates between self-recruiting and immigrant larvae. We also quantified otolith Sr/Ca and Ba/Ca ratios during the larval phase using laser ablation inductively coupled plasma mass spectrometry. Again, we found no significant differences in larval profiles of either element between self-recruits and immigrants. Our results highlight the need for caution when interpreting otolith dispersal histories based on natural geochemical tags in the absence of water chemistry data or known-origin larvae with which to test the discriminatory ability of natural tags.

  2. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics.

    Science.gov (United States)

    Smith, W E; Kwak, T J

    2014-04-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  3. Variations in otolith patterns, sizes and body morphometrics of jack mackerel Trachurus japonicus juveniles.

    Science.gov (United States)

    Kanaji, Y; Kishida, M; Watanabe, Y; Kawamura, T; Xie, S; Yamashita, Y; Sassa, C; Tsukamoto, Y

    2010-10-01

    Variations in otolith patterns, sizes and body morphometrics of jack mackerel Trachurus japonicus juveniles were investigated. Under transmitted light, translucent (W(t)) and opaque otoliths (W(o)) were detected in juveniles collected from Wakasa Bay between July 2005 and April 2006, whereas only opaque otoliths (G(o)) were detected in Goto-nada Sea individuals between May and June 2006. Three groups of juveniles were distinguished based on differences in hatch season, otolith size and growth history, and body morphometrics. As T. japonicus has different spawning seasons according to spawning grounds, each group was estimated to hatch in different waters. Juveniles with W(t) otoliths were considered to have stayed in coastal habitat longer, as the hatch area was estimated to be near Wakasa Bay. Juveniles with W(o) and G(o) otoliths appear to recruit to coastal waters at larger size, since their hatch areas were estimated to be far from each collection area. Larger otoliths of W(t) were attributed to otolith accretion after the second growth flexion, which was observed only for W(t) . Standard length of W(t) fish at the second otolith growth flexion was estimated to correspond to recruitment size to coastal rocky reefs in Wakasa Bay. Body morphometrics were correlated with otolith size after removing body size effect, suggesting that morphological variations of T. japonicus juveniles were also associated with the timing of recruitment to coastal habitat. PMID:21039508

  4. Variations in otolith patterns, sizes and body morphometrics of jack mackerel Trachurus japonicus juveniles.

    Science.gov (United States)

    Kanaji, Y; Kishida, M; Watanabe, Y; Kawamura, T; Xie, S; Yamashita, Y; Sassa, C; Tsukamoto, Y

    2010-10-01

    Variations in otolith patterns, sizes and body morphometrics of jack mackerel Trachurus japonicus juveniles were investigated. Under transmitted light, translucent (W(t)) and opaque otoliths (W(o)) were detected in juveniles collected from Wakasa Bay between July 2005 and April 2006, whereas only opaque otoliths (G(o)) were detected in Goto-nada Sea individuals between May and June 2006. Three groups of juveniles were distinguished based on differences in hatch season, otolith size and growth history, and body morphometrics. As T. japonicus has different spawning seasons according to spawning grounds, each group was estimated to hatch in different waters. Juveniles with W(t) otoliths were considered to have stayed in coastal habitat longer, as the hatch area was estimated to be near Wakasa Bay. Juveniles with W(o) and G(o) otoliths appear to recruit to coastal waters at larger size, since their hatch areas were estimated to be far from each collection area. Larger otoliths of W(t) were attributed to otolith accretion after the second growth flexion, which was observed only for W(t) . Standard length of W(t) fish at the second otolith growth flexion was estimated to correspond to recruitment size to coastal rocky reefs in Wakasa Bay. Body morphometrics were correlated with otolith size after removing body size effect, suggesting that morphological variations of T. japonicus juveniles were also associated with the timing of recruitment to coastal habitat.

  5. Evaluation of the otolith function using sinusoidal off-vertical axis rotation in patients with benign paroxysmal positional vertigo.

    Science.gov (United States)

    Sugita-Kitajima, Akemi; Azuma, Miki; Hattori, Kosuke; Koizuka, Izumi

    2007-07-01

    The vestibulo-ocular reflex (VOR) was studied via sinusoidal off-vertical axis rotation (OVAR) to evaluate the otolith function in patients with benign paroxysmal positional vertigo (BPPV). Subjects were sinusoidally rotated with eyes open in complete darkness at frequencies of 0.4 and 0.8 Hz with a maximum angular velocity of 60 degrees s(-1) in earth-vertical axis rotation (EVAR) and OVAR. Twenty-three controls and 24 BPPV patients were investigated. Results showed that VOR gain during OVAR at 0.8 Hz in a 30 degrees nose-up position in BPPV patients was significantly less than the gain during EVAR, whereas the gain was not significantly different between EVAR and OVAR in the controls in each condition. In addition, to examine each type of BPPV, we also investigated whether there were any differences between the patients who suffered from dizziness and those who did not. VOR gain in OVAR of BPPV patients who were suffering from dizziness was significantly less than that of BPPV patients without dizziness. Not only cupulolithiasis or canalolithiasis, but also otolith dysfunction was considered to be the possible origin of BPPV. Because sinusoidal OVAR produced minimal nausea compared to constant velocity OVAR, the stimulation of 0.8 Hz nose-up in sinusoidal OVAR may be used to evaluate otolith function without discomfort for patients. PMID:17597299

  6. Otoliths as recorders of palaeoenvironments: comparison of radiocarbon age and isoleucine epimerization in Pleistocene golden perch 'Macquaria ambigua' otoliths from Willandra Lakes

    International Nuclear Information System (INIS)

    Fish otoliths form by the accretion of layers of calcium carbonate and organic-rich material that often form distinctive layers over time scales ranging from days to years. These layers are not resorbed during the life of the fish and have potential to provide data relevant to both the biology of the fish and the environment to which the fish has been exposed. Environmental variability based on otoliths can be estimated through measures of stable oxygen isotopes, trace elements, and the widths of both daily and annual increments. Although otoliths can be dated based on measurement of radiocarbon by accelerator mass spectrometry this method is relatively expensive. An alternative method for dating golden perch otoliths is based on measurements of isoleucine D/L ratios. Miller and Rosewater (1995) demonstrated that golden perch otoliths are near a perfect closed system for racemization and that otoliths have potential of dating surrounding sediments older than 100 ka. Despite the suitability of these structures for racemization measurements, many of collections of Pleistocene otoliths from Willandra Lakes are not appropriate for determination of sample age. Most otoliths sampled in the region have been derived from surface collections, while it is recommended that samples should have been buried at least 1 m during most of their history. Therefore, the majority of existing otolith collections are not appropriate for geochronology or palaeothermometry. Nevertheless, when used in conjunction with radiocarbon dates, racemization data may be of value in assessing the relationship among otoliths in an assemblage. Radiocarbon ages and isoleucine D/L ratios were determined for 30 otoliths collected from Willandra Lakes. The rostrum of each otolith was analysed for D/L ratios and a portion of the posterior of the same otolith was analysed for radiocarbon by accelerator mass spectrometry. Sample weights for both analyses ranged from 14.0 to 25.6 mg. The central portion of the

  7. Does DNA extraction affect the physical and chemical composition of historical cod (Gadus morhua) otoliths?

    DEFF Research Database (Denmark)

    Therkildsen, Nina Overgaard; Eg Nielsen, Einar; Hüssy, Karin;

    2010-01-01

    conflicting interests regarding how the limited and irreplaceable otolith collections should be used. To resolve this, it is important to find out whether DNA extraction damages otoliths such that they can no longer be used for other research purposes or whether individual otoliths can be used in multiple...... applications. We examined the effects of three different DNA extraction methods on the elemental composition, the morphology, and the clarity of annual growth increments for successful age estimation of Atlantic cod (Gadus morhua) otoliths that had been archived for 0–31 years. The three extraction methods...... yielded DNA of comparable quality, and none of the methods caused major damage to the otoliths. Of the element concentrations measured, only Mg and Rb showed considerable changes resulting from DNA extraction. The physical properties of the otolith (morphology and clarity of annual growth increments) were...

  8. Temporal stability of otolith elemental fingerprints discriminates among lagoon nursery habitats

    OpenAIRE

    Tournois, J.; Ferraton, Franck; Velez, Laure; D.J. McKenzie; Aliaume, C.; L. Mercier; Darnaude, A. M.

    2013-01-01

    The chemical composition of fish otoliths reflects that of the water masses that they inhabit. Otolith elemental compositions can, therefore, be used as natural tags to discriminate among habitats. However, for retrospective habitat identification to be valid and reliable for any adult, irrespective of its age, significant differences in environmental conditions, and therefore otolith signatures, must be temporally stable within each habitat, otherwise connectivity studies have to be carried ...

  9. Three-dimensional rendering of otolith growth using phase contrast synchrotron tomography.

    Science.gov (United States)

    Mapp, J J I; Fisher, M H; Atwood, R C; Bell, G D; Greco, M K; Songer, S; Hunter, E

    2016-05-01

    A three-dimensional computer reconstruction of a plaice Pleuronectes platessa otolith is presented from data acquired by the Diamond Light synchrotron, beamline I12, X-ray source, a high energy (53-150 keV) source particularly well suited to the study of dense objects. The data allowed non-destructive rendering of otolith structure, and for the first time allows otolith annuli (internal ring structures) to be analysed in X-ray tomographic images. PMID:27071346

  10. Within-otolith variability in chemical fingerprints: implications for sampling designs and possible environmental interpretation.

    Directory of Open Access Journals (Sweden)

    Antonio Di Franco

    Full Text Available Largely used as a natural biological tag in studies of dispersal/connectivity of fish, otolith elemental fingerprinting is usually analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS. LA-ICP-MS produces an elemental fingerprint at a discrete time-point in the life of a fish and can generate data on within-otolith variability of that fingerprint. The presence of within-otolith variability has been previously acknowledged but not incorporated into experimental designs on the presumed, but untested, grounds of both its negligibility compared to among-otolith variability and of spatial autocorrelation among multiple ablations within an otolith. Here, using a hierarchical sampling design of spatial variation at multiple scales in otolith chemical fingerprints for two Mediterranean coastal fishes, we explore: 1 whether multiple ablations within an otolith can be used as independent replicates for significance tests among otoliths, and 2 the implications of incorporating within-otolith variability when assessing spatial variability in otolith chemistry at a hierarchy of spatial scales (different fish, from different sites, at different locations on the Apulian Adriatic coast. We find that multiple ablations along the same daily rings do not necessarily exhibit spatial dependency within the otolith and can be used to estimate residual variability in a hierarchical sampling design. Inclusion of within-otolith measurements reveals that individuals at the same site can show significant variability in elemental uptake. Within-otolith variability examined across the spatial hierarchy identifies differences between the two fish species investigated, and this finding leads to discussion of the potential for within-otolith variability to be used as a marker for fish exposure to stressful conditions. We also demonstrate that a 'cost'-optimal allocation of sampling effort should typically include some level of within-otolith

  11. Provenancing fish in freshwaters of the Alpine Foreland using Sr/Ca and 87Sr/86Sr ratios in otoliths and otolith shape parameters

    Directory of Open Access Journals (Sweden)

    Johannes Oehm

    2015-12-01

    Although the studied freshwaters were located only in a 50 km range around lake Chiemsee on a similar geological background, differences in water chemistry, fish otolith chemistry and shape were identified. Species specific differences in reflection of the Sr/Ca ratio of a specific water body were detected. Microchemical and morphological otoliths analyses complemented each other and allowed assigning fish to specific groups of waters of origin. This information provides an important basis for the further application of otolith chemistry and shape analysis in the Alpine foreland for a diverse range of ecological questions.

  12. Spatial and ontogenetic variability in the chemical composition of juvenile common sole ( Solea solea) otoliths

    Science.gov (United States)

    Tanner, S. E.; Vasconcelos, R. P.; Reis-Santos, P.; Cabral, H. N.; Thorrold, S. R.

    2011-01-01

    A description of variations in the chemical composition of fish otoliths at different spatial scales and life history stages is a prerequisite for their use as natural tags in fish population connectivity and migration studies. Otolith geochemistry of juvenile common sole ( Solea solea), a marine migrant species collected in six Portuguese estuaries was examined. Elemental ratios (Mg:Ca, Mn:Ca, Cu:Ca, Sr:Ca, Ba:Ca, Pb:Ca) were analysed in two zones of the right otolith (corresponding to late larval and juvenile stages) using laser ablation inductively coupled plasma mass spectrometry (ICP-MS). Stable carbon and oxygen isotopes (δ 13C and δ 18O) were determined in left otoliths using isotopic ratio monitoring mass spectrometry (irm-MS). Significant differences in otolith geochemical signatures were found among estuaries, among sites within estuaries and between otolith zones. Several elemental ratios (Mg:Ca, Mn:Ca, Cu:Ca and Sr:Ca) showed consistent patterns between otolith zones and were likely influenced by environmental factors and ontogenetic effects associated with physiological changes during metamorphosis. Assignment of individuals to their collection estuary based on the otolith geochemical signatures was more accurate at the site level (81%) than among estuaries (69%). Site temperature was not correlated with any of the elemental or isotope ratios, but salinity was significantly correlated with Ba:Ca, δ 13C and δ 18O. Observed spatial variations among estuaries and sites within estuaries indicate that geochemical signatures in otoliths are accurate natural tags of estuarine habitat in common sole. Nevertheless, the significant variations observed between otolith zones should be taken into account in the design of population connectivity studies.

  13. Using otolith microchemistry and shape to assess the habitat value of oil structures for reef fish.

    Science.gov (United States)

    Fowler, Ashley M; Macreadie, Peter I; Bishop, David P; Booth, David J

    2015-05-01

    Over 7500 oil and gas structures (e.g. oil platforms) are installed in offshore waters worldwide and many will require decommissioning within the next two decades. The decision to remove such structures or turn them into reefs (i.e. 'rigs-to-reefs') hinges on the habitat value they provide, yet this can rarely be determined because the residency of mobile species is difficult to establish. Here, we test a novel solution to this problem for reef fishes; the use of otolith (earstone) properties to identify oil structures of residence. We compare the otolith microchemistry and otolith shape of a site-attached coral reef fish (Pseudanthias rubrizonatus) among four oil structures (depth 82-135 m, separated by 9.7-84.2 km) on Australia's North West Shelf to determine if populations developed distinct otolith properties during their residency. Microchemical signatures obtained from the otolith edge using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) differed among oil structures, driven by elements Sr, Ba and Mn, and to a lesser extent Mg and Fe. A combination of microchemical data from the otolith edge and elliptical Fourier (shape) descriptors allowed allocation of individuals to their 'home' structure with moderate accuracy (overall allocation accuracy: 63.3%, range: 45.5-78.1%), despite lower allocation accuracies for each otolith property in isolation (microchemistry: 47.5%, otolith shape: 45%). Site-specific microchemical signatures were also stable enough through time to distinguish populations during 3 separate time periods, suggesting that residence histories could be recreated by targeting previous growth zones in the otolith. Our results indicate that reef fish can develop unique otolith properties during their residency on oil structures which may be useful for assessing the habitat value of individual structures. The approach outlined here may also be useful for determining the residency of reef fish on artificial reefs, which would

  14. Reproductive biology of Otolithes cuvieri (Trewavas, 1974) from Mumbai waters

    OpenAIRE

    Telvekar, P.A.; Chakraborty, S. K.; Jaiswar, A.K.

    2005-01-01

    The reproductive biology of Otolithes cuvieri (Trewavas, 1974) is reported in the present communication. The size at first maturity for the females was estimated to be 275 mm. The spawning activity was observed throughout the year with two peaks occurring in April and June. Two prominent peaks of gonadosomatic index (April and June) also support the view of two major spawning. Relative fecundity ranged from 71,574 to 79,680 eggs per 100g of body weight. Relationship of fecundity with fish len...

  15. Otolith shape analysis of the austral sardine (Sprattus fuegensis in the Patagonian inner sea of Chile.

    Directory of Open Access Journals (Sweden)

    Luis A Cubillos

    2015-11-01

    Full Text Available The austral sardine has an extensive distribution within inner and outer waters along fiords, channels, and the continental shelf of the Chilean Patagonia, from Puerto Montt to Tierra del Fuego and extending to southern Argentina. With the aim of determining differences in morphology and shape of sagittal otoliths of the austral sardine, samples were obtained from inner waters of Chiloé (42ºS-43ºS, Aysén (44ºS-46ºS, Punta Arenas (54ºS, and from Argentinian waters. Traditional morphometry analysis considered length, width, area, perimeter, and size-based shape descriptors of otoliths. Instead, geometric morphometry was an outline otolith analysis on the basis of elliptic Fourier descriptors through multivariate statistical methods. Both approached showed intraspecific variability in otolith shape of austral sardine, with otoliths from inner waters of Chiloé statistically differenced from the Aysén Region, but with an important degree of mix between zones. Otoliths from Punta Arenas were excluded from the study because they were smaller, without the outline characteristic of the adult specimens. The sagittal otolith from inner waters of Chiloé exhibited an elliptical shape, defined rostrum, and concave antirostrum, while otoliths from the Aysén Región showed rounded shape along the dorsal and ventral borders, without defined postrostrum and antirostrum. The otolith rostrum of specimens from inner waters of Chiloé was very well defined, being this the main morphological trait generating differences with the rest of the zones.

  16. An evaluation of agreement between pectoral spines and otoliths for estimating ages of catfishes

    Science.gov (United States)

    Olive, J.A.; Schramm, Harold; Gerard, Patrick D.; Irwin, E.

    2011-01-01

    Otoliths have been shown to provide more accurate ages than pectoral spine sections for several catfish populations; but sampling otoliths requires euthanizing the specimen, whereas spines can be sampled non-lethally. To evaluate whether, and under what conditions, spines provide the same or similar age estimates as otoliths, we examined data sets of individual fish aged from pectoral spines and otoliths for six blue catfish Ictalurus furcatus populations (n=420), 14 channel catfish Ictalurus punctatus populations (n=997), and 10 flathead catfish Pylodictus olivaris populations (n=947) from lotic and lentic waters throughout the central and eastern U.S. Logistic regression determined that agreement between ages estimated from otoliths and spines was consistently related to age, but inconsistently related to growth rate. When modeled at mean growth rate, we found at least 80% probability of no difference in spine- and otolith-assigned ages up to ages 4 and 5 for blue and channel catfish, respectively. For flathead catfish, an 80% probability of agreement between spine- and otolith-assigned ages did not occur at any age due to high incidence of differences in assigned ages even for age-1 fish. Logistic regression models predicted at least 80% probability that spine and otolith ages differed by ≤1 year up to ages 13, 16, and 9 for blue, channel, and flathead catfish, respectively. Age-bias assessment found mean spine-assigned age differed by less than 1 year from otolith-assigned age up to ages 19, 9, and 17 for blue catfish, channel catfish, and flathead catfish, respectively. These results can be used to help guide decisions about which structure is most appropriate for estimating catfish ages for particular populations and management objectives.

  17. A bioenergetic approach to model and reconstruct individual life traits from fish otoliths

    DEFF Research Database (Denmark)

    Fablet, Ronan; Pecquerie, Laure; Høie, Hans;

    2012-01-01

    Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm‐following formation provides individual records of the age, the individual history, and the natural environment of extinct and living fish species. Such data are critical for ecosy...... observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves...

  18. Otolith Sr concentration analyzed by PIXE in Ariake estuary-dependent sea bass juveniles

    International Nuclear Information System (INIS)

    Japanese sea bass (Lateolabrax japonicus) is a typical euryhaline marine fish and frequently migrates from salt to freshwater environments during early life stages. We hypothesized that strontium concentrations in the otolith could be a useful index to examine freshwater entry because of its lower concentration in freshwater. Otoliths of Japanese sea bass juveniles collected in the Chikugo river and estuary were analyzed by Particle Induced X-ray Emission (PIXE) to see relationship between strontium concentration and ambient salinity. Strontium concentrations in otoliths of sea bass juveniles are significantly lower in the river samples than in brackish water samples. (author)

  19. Epigenetic disruption of cadherin-11 in human cancer metastasis

    OpenAIRE

    Carmona, F.Javier; Villanueva, Alberto; Vidal, August; Muñoz, Clara; Puertas, Sara; Penin, Rosa M; Gomà, Montserrat; Lujambio, Amaia; Piulats, Josep M.; Mesía, Ricard; Sánchez-Céspedes, Montse; Manós, Manel; Condom, Enric; Eccles, Suzanne A; Esteller, Manel

    2012-01-01

    Little is known about the molecular events occurring in the metastases of human tumours. Epigenetic alterations are dynamic lesions that change over the natural course of the disease, and so they might play a role in the biology of cancer cells that have departed from the primary tumour. Herein, we have adopted an epigenomic approach to identify some of these changes. Using a DNA methylation microarray platform to compare paired primary tumour and lymph node metastatic cell lines from the sam...

  20. Strontium content in otoliths of common fish species in the northern Baltic Sea

    International Nuclear Information System (INIS)

    Full text: The salinity of water in the northern Baltic Sea forms a gradient as it receives fresh water from several large rivers in the north and salty water by infrequent inflows of North Sea water in the south. The salinity of brackish water in the north-south direction (700 km) changes from about 3 to 7%. In an attempt to use the salinity gradient to study migration patterns, sagittae otoliths were collected from common fish species caught at different locations along the Finnish west coast. Otoliths from fishes caught in fresh-water lakes in Finland and Estonia were also included in the study for comparison. Part of the otoliths was grind and the powder was pressed to pellets which were irradiated in air with an ion beam from the Abo Akademi cyclotron and the emitted X-rays were measured. Other otoliths were embedded in epoxy and polished to reveal the ring structure. These prepared otoliths were irradiated with the ion beam to determine elemental profiles. Furthermore, XRD was applied to study the crystal structure and to identify the minerals in the otoliths. The strontium level of water is usually related to its salinity, and as the strontium ions are able to replace calcium ions in fish otoliths [1], the strontium content in fish otoliths from the same locations is expected to be very similar. However, the PIXE analyses revealed large differences in the strontium content between otoliths from different species of fish caught at the same locations. The strontium concentration in otoliths of perch and pike from the Aland Islands was about 1600 μg/g and of common whitefish 3600 μg/g. The strontium concentration in perch otoliths from the Oravais archipelago, about 400 km north of the Aland Islands, was 1400 μg/g. Corresponding concentration in otoliths of perch and pike caught in fresh-water lakes was 200 μg/g and of common whitefish from Saadjarve 400 μg/g and from Lake Inari 1000 μg/g. Otoliths of perch contained no detectable amounts of zinc (Iower

  1. Off-vertical axis rotation: a test of the otolith-ocular reflex

    Science.gov (United States)

    Furman, J. M.; Schor, R. H.; Schumann, T. L.

    1992-01-01

    The vestibulo-ocular reflex was studied via off-vertical axis rotation (OVAR) in the dark. The axis of the turntable could be tilted from vertical by up to 30 degrees. Eye movements were measured with electro-oculography. Results from healthy asymptomatic subjects indicated that 1) a reliable otolith-induced response could be obtained during constant velocity OVAR using a velocity of 60 degrees/s with a tilt of 30 degrees; 2) constant velocity OVAR rotation was nausea-producing and, especially if subjects were rotated in the dark about an earth-vertical axis prior to being tilted, disorienting; and 3) sinusoidal OVAR produced minimal nausea; the eye movement response appeared to be the result of a combination of semicircular canal and otolith components. We conclude that OVAR has the potential of becoming a useful method for clinically assessing both the otolith-ocular reflex and semicircular canal-otolith interaction.

  2. Otolith Formation in A Mutant Medaka Fish with A Deficiency in Gravity- Sensing

    Science.gov (United States)

    Mizuno, R.; Ijiri, K.

    Formation of otoliths in Medaka fish (Oryzias latipes) were studied in the normal (wild-type) fish and in a mutant strain called ha. In the normal fish, two pairs of otoliths (Lapillus and Sagitta) are formed during embryonic development, and the most posterior otolith (Asteriscus) are formed later (about 30 days after hatching). In the mutant strain ha, though Sagittae are formed, Lapilli are absent at hatching. Asterisca are formed normally. Various abnormalities in the formation of Sagittae were detected in ha strain, however, they eventually took normal shapes and positions on the maculae. After hatching, in some ha fish, Lapilli are formed. On 30 days and 40 days after hatching, the appearance of Lapilli were examined by X-ray photography. The results showed that some fis h had a complete pair, some had only one otolith either at the right or left side, and the rest of fish lacked Lapilli completely.

  3. Comparative Transduction Mechanisms of Vestibular Otolith Hair Cells

    Science.gov (United States)

    Baird, Richard A.

    1994-01-01

    Hair cells in the bullfrog vestibular otolith organs regenerate following aminoglycoside ototoxicity. Hair cells in these organs are differentially sensitive to gentamicin, with saccular hair cells and hair cells in the utricular striola being damaged at lower gentamicin concentrations than hair cells in the utricular extrastriola. Regenerating hair cells in these organs have short hair bundles and can be classified into a number of phenotypes using the same morphological criteria used to identify their mature counterparts. Our studies suggest that some supporting cells can convert, or transdifferentiate,into hair cells without an intervening cell division. By stimulating these processes in humans, clinicians may be able to alleviate human deafness and peripheral vestibular disorders by regenerating and replacing lost hair cells. In vivo and in vitro studies were done on cell proliferation and hair cell regeneration.

  4. Validation of daily increment formation in otoliths for Gymnocypris selincuoensis in the Tibetan Plateau, China

    OpenAIRE

    Ding, Chengzhi; Chen, Yifeng; He, Dekui; Tao, Juan

    2015-01-01

    Daily increment validation in fish otolith is fundamental to studies on fish otolith microstructure, age determination and life history traits, and thus is critical for species conservation and fishery management. However, it has never been done for Schizothoracine fish, which is the dominant component of fish fauna in the Tibetan Plateau. This study validated the daily increment formation of Gymnocypris selincuoensis, as a representative of Schizothoracine fish, by monitoring the growth of h...

  5. Documenting utility of paddlefish otoliths for quantification of metals using inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Long, James M.; Schaffler, James J.

    2013-01-01

    RATIONALE The otoliths of the inner ear of fishes record the environment of their surrounding water throughout their life. For paddlefish (Polyodon spathula), otoliths have not been routinely used by scientists since their detriments were outlined in the early 1940s. We sought to determine if paddlefish otoliths were useful for resolving elemental information contained within. METHODS Adult paddlefish were collected from two wild, self-sustaining populations in Oklahoma reservoirs in the Arkansas River basin. Juveniles were obtained from a hatchery in the Red River basin of Oklahoma. Otoliths were removed and laser ablation, inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify eight elements (Li, Mg, Mn, Rb, Sr, Y, Ba, and Pb) along the core and edge portions, which were analyzed for differences between otolith regions and among paddlefish sources. RESULTS Differences were found among samples for six of the eight elements examined. Otoliths from Red River basin paddlefish born in a hatchery had significantly lower amounts of Mg and Mn, but higher levels of Rb than otoliths from wild paddlefish in the Arkansas River basin. Concentrations of Y, Sr, and Ba were reduced on the edges of adult paddlefish from both reservoirs compared with the cores. CONCLUSIONS This research shows the utility of using an ICP-MS analysis of paddlefish otoliths. Future research that seeks to determine sources of paddlefish production, such as which reservoir tributaries are most important for reproduction or what proportion of the population is composed of wild versus hatchery-produced individuals, appears promising. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

  6. An evaluation of the precision of fin ray, otolith, and scale age determinations for brook trout

    Science.gov (United States)

    Stolarski, J.T.; Hartman, K.J.

    2008-01-01

    The ages of brook trout Salvelinus fontinalis are typically estimated using scales despite a lack of research documenting the effectiveness of this technique. The use of scales is often preferred because it is nonlethal and is believed to require less effort than alternative methods. To evaluate the relative effectiveness of different age estimation methodologies for brook trout, we measured the precision and processing times of scale, sagittal otolith, and pectoral fin ray age estimation techniques. Three independent readers, age bias plots, coefficients of variation (CV = 100 x SD/mean), and percent agreement (PA) were used to measure within-reader, among-structure bias and within-structure, among-reader precision. Bias was generally minimal; however, the age estimates derived from scales tended to be lower than those derived from otoliths within older (age > 2) cohorts. Otolith, fin ray, and scale age estimates were within 1 year of each other for 95% of the comparisons. The measures of precision for scales (CV = 6.59; PA = 82.30) and otoliths (CV = 7.45; PA = 81.48) suggest higher agreement between these structures than with fin rays (CV = 11.30; PA = 65.84). The mean per-sample processing times were lower for scale (13.88 min) and otolith techniques (12.23 min) than for fin ray techniques (22.68 min). The comparable processing times of scales and otoliths contradict popular belief and are probably a result of the high proportion of regenerated scales within samples and the ability to infer age from whole (as opposed to sectioned) otoliths. This research suggests that while scales produce age estimates rivaling those of otoliths for younger (age > 3) cohorts, they may be biased within older cohorts and therefore should be used with caution. ?? Copyright by the American Fisheries Society 2008.

  7. Age, growth and distribution of the Antarctic fish Chaenocephalus aceratus based on otoliths

    OpenAIRE

    Ryszard Jacek Traczyk

    2015-01-01

    The Chaenocephalus aceratus were sampled in the summer between 1979 and 1990 at South Georgia Is. The problems of ageing Antarctic fish Channichthyidae are commonly known (Kock, 1989; Le_François, 2014; Campana, 2014) they have not scales and their bones undergo constant and large reduction (Żabrowski, 2000). It was found that the otoliths of C. aceratus show daily pattern of microincrements as otoliths of similar species Pseudochaenichthys georgianus, Champsocephalus gunnari and fishes both ...

  8. Strontium and zinc concentrations in otoliths of common fish species in the northern Baltic Sea

    Science.gov (United States)

    Lill, J.-O.; Himberg, M.; Harju, L.; Ek, P.; Lindroos, A.; Wiklund, T.; Gunnelius, K.; Smått, J.-H.; Heselius, S.-J.; Hägerstrand, H.

    2014-01-01

    Otoliths of perch (Perca fluviatilis), pike (Esox lucius) and European whitefish (Coregonus lavaretus) caught at different locations in the northern Baltic Sea along the Finnish west coast and at some rivers and lakes were subjected to elemental analyses with particle induced X-ray emission and laser ablation inductively coupled plasma mass spectrometry. The strontium concentration in otoliths from whitefish (˜3300 μg/g) was 2-3 times higher than that of perch and pike (˜1400 μg/g), while within species the strontium concentration of otoliths from fish caught at different locations was in the same range. The strontium concentrations were lowest in fish from the lakes (˜450 μg/g). Whitefish otoliths contained more zinc (˜60 μg/g) than those of pike (˜30 μg/g), while the zinc concentration in perch otoliths were below the detection limit. No spatial intraspecies variations in zinc concentrations were observed. X-ray diffraction showed that the otoliths consisted of aragonite solely.

  9. Integrating microsatellite DNA markers and otolith geochemistry to assess population structure of European hake (Merluccius merluccius)

    Science.gov (United States)

    Tanner, Susanne E.; Pérez, Montse; Presa, Pablo; Thorrold, Simon R.; Cabral, Henrique N.

    2014-04-01

    Population structure and natal origins of European hake were investigated using microsatellite DNA markers and otolith geochemistry data. Five microsatellites were sequenced and otolith core geochemical composition was determined from age-1 hake collected in the northeast Atlantic Ocean and the Mediterranean Sea. Microsatellites provided evidence of a major genetic split in the vicinity of the Strait of Gibraltar, separating the Atlantic and the Mediterranean populations, with the exception of the Gulf of Cádiz. Based on classification models using otolith core geochemical values, individual natal origins were identified, although with an increased error rate. Coupling genotype and otolith data increased the classification accuracy of individuals to their potential natal origins while providing evidence of movement between the northern and southern stock units in the Atlantic Ocean. Information obtained by the two natural markers on population structure of European hake was complementary as the two markers act at different spatio-temporal scales. Otolith geochemistry provides information over an ecological time frame and on a fine spatial scale, while microsatellite DNA markers report on gene flow over evolutionary time scales and therefore act on a broader spatio-temporal resolution. Thus, this study confirmed the value of otolith geochemistry to complement the assessment of early life stage dispersal in populations with high gene flow and low genetic divergence.

  10. Strontium and zinc concentrations in otoliths of common fish species in the northern Baltic Sea

    International Nuclear Information System (INIS)

    Otoliths of perch (Perca fluviatilis), pike (Esox lucius) and European whitefish (Coregonus lavaretus) caught at different locations in the northern Baltic Sea along the Finnish west coast and at some rivers and lakes were subjected to elemental analyses with particle induced X-ray emission and laser ablation inductively coupled plasma mass spectrometry. The strontium concentration in otoliths from whitefish (∼3300 μg/g) was 2–3 times higher than that of perch and pike (∼1400 μg/g), while within species the strontium concentration of otoliths from fish caught at different locations was in the same range. The strontium concentrations were lowest in fish from the lakes (∼450 μg/g). Whitefish otoliths contained more zinc (∼60 μg/g) than those of pike (∼30 μg/g), while the zinc concentration in perch otoliths were below the detection limit. No spatial intraspecies variations in zinc concentrations were observed. X-ray diffraction showed that the otoliths consisted of aragonite solely

  11. Near-reef elemental signals in the otoliths of settling Pomacentrus amboinensis (Pomacentridae)

    Science.gov (United States)

    Sih, Tiffany L.; Kingsford, Michael J.

    2016-03-01

    Settlement is a key life history transition for coral reef fishes, and how long a fish spends close to a reef prior to settlement is poorly understood. We used laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and otolith microstructure analysis (daily increments and settlement marks) to determine the length of time larval fish spend near a reef prior to settlement. The otoliths of Pomacentrus amboinensis collected from four neighbouring reefs in the southern Great Barrier Reef showed clear and consistent differences in their elemental signatures prior to and following settlement. Elevated Ba:Ca near settlement and post-settlement was found in fish from all four reefs. However, there was individual variation in elemental profiles, with an increased otolith Ba-to-Ca ratio (near-reef signature) at settlement in 33 % of fish, and up to 8 d prior to settlement in others. Increment widths, often used as a proxy for growth, decreased approaching the settlement mark for all fish, providing further evidence for a "search phase" in larvae. We demonstrated experimentally that otoliths of fish kept in reefal or inter-reefal waters had different elemental chemistry. There were differences in the elemental composition of water samples within the study area, but no consistent trends with distance from reefs. There was poor discrimination of multi-element signatures among fish from different reefs during their pre-settlement phases. However, discrimination improved in the settlement and post-settlement phases of otoliths, indicating that reef waters and perhaps stage of ontogeny affected otolith chemistry. This study demonstrated clear near-reef elemental signatures in fish around settlement. We suggest these differences are due to a combination of water chemistry and physiological influences (e.g., growth). Combining LA-ICP-MS with otolith microstructure analysis can provide high-resolution information on the early life history of reef fishes. Further, a

  12. Carbon isotopes in otolith amino acids identify residency of juvenile snapper (Family: Lutjanidae) in coastal nurseries

    Science.gov (United States)

    McMahon, K. W.; Berumen, M. L.; Mateo, I.; Elsdon, T. S.; Thorrold, S. R.

    2011-12-01

    This study explored the potential for otolith geochemistry in snapper (Family: Lutjanidae) to identify residency in juvenile nursery habitats with distinctive carbon isotope values. Conventional bulk otolith and muscle stable isotope analyses (SIA) and essential amino acid (AA) SIA were conducted on snapper collected from seagrass beds, mangroves, and coral reefs in the Red Sea, Caribbean Sea, and Pacific coast of Panama. While bulk stable isotope values in otoliths showed regional differences, they failed to distinguish nursery residence on local scales. Essential AA δ13C values in otoliths, on the other hand, varied as a function of habitat type and provided a better tracer of residence in different juvenile nursery habitats than conventional bulk otolith SIA alone. A strong linear relationship was found between paired otolith and muscle essential AA δ13C values regardless of species, geographic region, or habitat type, indicating that otolith AAs recorded the same dietary information as muscle AAs. Juvenile snapper in the Red Sea sheltered in mangroves but fed in seagrass beds, while snapper from the Caribbean Sea and Pacific coast of Panama showed greater reliance on mangrove-derived carbon. Furthermore, compound-specific SIA revealed that microbially recycled detrital carbon, not water-column-based new phytoplankton carbon, was the primary carbon source supporting snapper production on coastal reefs of the Red Sea. This study presented robust tracers of juvenile nursery residence that will be crucial for reconstructing ontogenetic migration patterns of fishes among coastal wetlands and coral reefs. This information is key to determining the importance of nursery habitats to coral reef fish populations and will provide valuable scientific support for the design of networked marine-protected areas.

  13. Carbon isotopes in otolith amino acids identify residency of juvenile snapper (Family: Lutjanidae) in coastal nurseries

    KAUST Repository

    McMahon, Kelton

    2011-08-26

    This study explored the potential for otolith geochemistry in snapper (Family: Lutjanidae) to identify residency in juvenile nursery habitats with distinctive carbon isotope values. Conventional bulk otolith and muscle stable isotope analyses (SIA) and essential amino acid (AA) SIA were conducted on snapper collected from seagrass beds, mangroves, and coral reefs in the Red Sea, Caribbean Sea, and Pacific coast of Panama. While bulk stable isotope values in otoliths showed regional differences, they failed to distinguish nursery residence on local scales. Essential AA δ13C values in otoliths, on the other hand, varied as a function of habitat type and provided a better tracer of residence in different juvenile nursery habitats than conventional bulk otolith SIA alone. A strong linear relationship was found between paired otolith and muscle essential AA δ13C values regardless of species, geographic region, or habitat type, indicating that otolith AAs recorded the same dietary information as muscle AAs. Juvenile snapper in the Red Sea sheltered in mangroves but fed in seagrass beds, while snapper from the Caribbean Sea and Pacific coast of Panama showed greater reliance on mangrove-derived carbon. Furthermore, compound-specific SIA revealed that microbially recycled detrital carbon, not water-column-based new phytoplankton carbon, was the primary carbon source supporting snapper production on coastal reefs of the Red Sea. This study presented robust tracers of juvenile nursery residence that will be crucial for reconstructing ontogenetic migration patterns of fishes among coastal wetlands and coral reefs. This information is key to determining the importance of nursery habitats to coral reef fish populations and will provide valuable scientific support for the design of networked marine-protected areas. © 2011 Springer-Verlag.

  14. Comparison of rainbow smelt age estimates from fin rays and otoliths

    Science.gov (United States)

    Walsh, M.G.; Maloy, A.P.; O'Brien, T. P.

    2008-01-01

    Rainbow smelt Osmerus mordax, although nonnative, are an important component of the offshore food web in the Laurentian Great Lakes. In Lake Ontario, we estimate ages of rainbow smelt annually to study population dynamics such as year-class strength and age-specific growth and mortality. Since the early 1980s, we have used pectoral fin rays to estimate rainbow smelt ages, but the sectioning and mounting of fin rays are time and labor intensive. Our objective was to assess the feasibility of using otoliths rather than fin rays to estimate rainbow smelt ages. Three readers interpreted the ages of 172 rainbow smelt (60-198 mm total length) based on thin sections of pectoral fin rays, whole otoliths with no preparation, and whole otoliths that had been cleared for 1 month in a 70:30 ethanol : glycerin solution. Bias was lower and precision was greater for fin rays than for otoliths; these results were consistent for comparisons within readers (first and second readings by one individual; three readers were used) and between readers (one reading for each reader within a pair). Both otolith methods appeared to misclassify age-1 rainbow smelt. Fin ray ages had the highest precision and provided the best approximation of age estimates inferred from the Lake Ontario population's length frequency distribution and from our understanding of this population. ?? American Fisheries Society 2008.

  15. Origins of invasive piscivores determined from the strontium isotope ratio (87Sr/86Sr) of otoliths

    Science.gov (United States)

    Wolff, Brian A.; Johnson, Brett M.; Breton, Andre R.; Martinez, Patrick J.; Winkelman, Dana L.; Gillanders, Bronwyn

    2012-01-01

    We examined strontium isotope ratios (87Sr/86Sr) in fish otoliths to determine the origins of invasive piscivores in the Upper Colorado River Basin (UCRB, western USA). We examined 87Sr/86Sr from fishes in different reservoirs, as well as the temporal stability and interspecies variability of 87Sr/86Sr of fishes within reservoirs, determined if 87Sr/86Sr would be useful for "fingerprinting" reservoirs where invasive piscivores may have been escaping into riverine habitat of endangered fishes in the UCRB, and looked for evidence that such movement was occurring. Our results showed that in most cases 87Sr/86Sr was unique among reservoirs, overlapped among species in a given reservoir, and was temporally stable across years. We identified the likely reservoir of origin of river-caught fish in some cases, and we were also able to determine the year of possible escapement. The approach allowed us to precisely describe the 87Sr/86Sr fingerprint of reservoir fishes, trace likely origins of immigrant river fish, and exclude potential sources, enabling managers to focus control efforts more efficiently. Our results demonstrate the potential utility of 87Sr/86Sr as a site-specific and temporally stable marker for reservoir fish and its promise for tracking fish movements of invasive fishes in river-reservoir systems.

  16. A new method to reconstruct fish diet and movement patterns from δ 13 C values in otolith amino acids

    KAUST Repository

    McMahon, Kelton W.

    2011-08-01

    Fish ecologists have used geochemical values in otoliths to examine habitat use, migration, and population connectivity for decades. However, it remains difficult to determine an unambiguous dietary δ 13C signature from bulk analysis of otolith. Studies to date have focused on the aragonite component of otoliths with less attention paid to the organic fraction. We describe the application of compound-specific stable isotope analysis (SIA) to analyze amino acid (AA) δ 13C values from small amounts (<1 mg) of otolith powder. We examined δ 13C values of otolith and muscle AAs from a reef-associated snapper (Lutjanus ehrenbergii (Peters, 1869)) collected along a carbon isotope gradient (isoscape) from seagrass beds to coral reefs. Carbon isotope values in otolith and muscle samples were highly correlated within and among coastal habitats. Moreover, δ 13C values of otolith AAs provided a purely dietary record that avoided dilution from dissolved inorganic carbon. Otolith AAs served as a robust tracer of δ 13C values at the base of the food web, making compound-specific SIA a powerful tool for dietary reconstructions and tracking the movement of fishes across isoscapes.

  17. Validating the use of embryonic fish otoliths as recorders of sublethal exposure to copper in estuarine sediments.

    Science.gov (United States)

    Barbee, Nicole C; Greig, Alan; Swearer, Stephen E

    2013-07-01

    In this study we explore the use of fish otoliths ('earbones') as a tool for detecting exposure to heavy metals in sediments. Because otoliths are metabolically inert and incorporate chemical impurities during growth, they can potentially provide a more permanent record of pollutant exposure history in aquatic environments than soft tissues. To validate this technique we cultured embryos of a native Australian fish, the common Galaxias (Galaxias maculatus), in the laboratory on sediments spiked with copper in a concentration gradient. Our aims were to test whether exposure to copper contaminated sediments is recorded in the otoliths of embryos and determine over what range in concentrations we can detect differences in exposure. We found elevated copper levels in otoliths of embryos exposed to high copper concentrations in sediments, suggesting that otoliths can be used as a tool to track a history of exposure to elevated copper levels in the environment. PMID:23628888

  18. Spatial variation in elemental composition of otoliths of three species of fish (family Sparidae)

    Science.gov (United States)

    Gillanders, B. M.; Kingsford, M. J.

    2003-08-01

    Determining the nursery habitat of fishes that have moved from estuarine nursery habitats is difficult. The elemental fingerprints of otoliths of three species of sparids were determined to investigate their utility as a natural tag of the nursery habitat. Juvenile Pagrus auratus (snapper), Rhabdosargus sarba (tarwhine) and Acanthopagrus australis (bream) were collected from two sites in each of 15, six and three estuaries, respectively, and their otoliths analysed by solution-based inductively coupled plasma-mass spectrometry. Significant differences in otolith chemistry were found for all three species of juveniles collected from different estuaries. The same patterns among estuaries were not seen for all species, although it was not possible to sample the same sites within an estuary for all species. For bream, significant differences in otolith chemistry were found among all three estuaries, whereas for tarwhine the six estuaries were separated into three groups. For snapper, a number of estuaries could be separated, but there was some overlap for other estuaries. All three species were collected from the same site within one estuary and their otoliths analysed. Significant differences were found among species, but the implication of this finding remains unclear as the three species show differences in microhabitat use and may also differ in age. Because the elemental fingerprints of juveniles vary among estuaries or groups of estuaries, the nursery or recruitment estuary of adult fish could now be determined by analysing the juvenile region of adult otoliths. Thus, connectivity between estuaries and open coastal populations could be determined. Such information will have major implications for fisheries management because it will provide information on the distance that fish have moved from their recruitment estuary and the number of estuaries that contribute to each adult population.

  19. Investigating bomb radiocarbon transport in the southern Pacific Ocean with otolith radiocarbon

    Science.gov (United States)

    Grammer, G. L.; Fallon, S. J.; Izzo, C.; Wood, R.; Gillanders, B. M.

    2015-08-01

    To explore the transport of carbon into water masses from the surface ocean to depths of ∼ 1000 m in the southwest Pacific Ocean, we generated time series of radiocarbon (Δ14C) from fish otoliths. Otoliths (carbonate earstones) from long-lived fish provide an indirect method to examine the "bomb pulse" of radiocarbon that originated in the 1950s and 1960s, allowing identification of changes to distributions of 14C that has entered and mixed within the ocean. We micro-sampled ocean perch (Helicolenus barathri) otoliths, collected at ∼ 400- 500 m in the Tasman Sea, to obtain measurements of Δ14C for those depths. We compared our ocean perch Δ14C series to published otolith-based marine surface water Δ14C values (Australasian snapper (Chrysophrys auratus) and nannygai (Centroberyx affinis)) and to published deep-water values (800-1000 m; orange roughy (Hoplostethus atlanticus)) from the southwest Pacific to establish a mid-water Δ14C series. The otolith bomb 14C results from these different depths were consistent with previous water mass results in the upper 1500 m of the southwest Pacific Ocean (e.g. World Ocean Circulation Experiment and Geochemical Ocean Sections Study). A comparison between the initial Δ14C bomb pulse rise at 400-500 m suggested a ventilation lag of 5 to 10 yr, whereas a comparison of the surface and depths of 800-1000 m detailed a 10 to 20 yr lag in the time history of radiocarbon invasion at this depth. Pre-bomb reservoir ages derived from otolith 14C located in Tasman Sea thermocline waters were ∼ 530 yr, while reservoir ages estimated for Tasman Antarctic intermediate water were ∼ 730 yr.

  20. Validation of otolith increment formation and the growth rate of fat greenling larvae

    OpenAIRE

    JOH, Mikimasa; Joh, Takashi; Matsu-ura, Teppei; Takatsu, Tetsuya

    2008-01-01

    We validated the daily formation 0f otolith increments of reared fat greenling Hexagrammos otakii larvae and examined the growth patterns of wild lavae. The mean notochord Length and otolith radius of newly hatched larvae were 8.31 mm and 273μm, respectively. Newly hatched larvae had some increments on their lapilli and a check was formed at hatching (hatch check). The relattonship between age and the number of increments formed outside the hatch chcck (NI)was linear regression (Nl=0.99Age-0....

  1. Barium variation in Pagrus auratus (Sparidae) otoliths: A potential indicator of migration between an embayment and ocean waters in south-eastern Australia

    Science.gov (United States)

    Hamer, Paul A.; Jenkins, Gregory P.; Coutin, Patrick

    2006-07-01

    Chronological variation in otolith chemistry can be used to reconstruct migration histories of fish. The use of otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into otoliths, and how water chemistry varies in space and time. We explored the potential for otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L -1 versus 6 μg L -1). Ba levels in otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba ( DBa) were similar for juvenile (0.43) and adult (0.46) otoliths, suggesting that otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence otolith Ba variation. We concluded that chronological Ba variation in snapper otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across otoliths of ocean resident snapper to estimate otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g -1) or coastal waters (confident interpretation of migration history from otolith Ba chronologies will most likely require matching time series of ambient Ba in the water bodies of interest.

  2. Otolith morphology and hearing abilities in cave- and surface-dwelling ecotypes of the Atlantic molly, Poecilia mexicana (Teleostei: Poeciliidae).

    Science.gov (United States)

    Schulz-Mirbach, Tanja; Ladich, Friedrich; Riesch, Rüdiger; Plath, Martin

    2010-08-01

    Cave fish have rarely been investigated with regard to their inner ear morphology, hearing abilities, and acoustic communication. Based on a previous study that revealed morphological differences in the saccular otolith between a cave and two surface populations of Poecilia mexicana, we checked for additional differences in utricular and lagenar otoliths and tested whether different populations have similar hearing sensitivities. We found pronounced differences in the shape of all three otoliths. Otoliths of the saccule and lagena from cave fish differed from those of surface fish in the features of the face oriented towards the sensory epithelium. In addition, otoliths of the utricle and lagena were significantly heavier in cave fish. Auditory sensitivities were measured between 100 and 1500Hz, utilizing the auditory evoked potential recording technique. We found similar hearing abilities in cave and surface fish, with greatest sensitivity between 200 and 300Hz. An acoustic survey revealed that neither ecotype produced species-specific sounds. Our data indicate that cave dwelling altered the otolith morphology in Atlantic mollies, probably due to metabolic differences. Different otolith morphology, however, did not affect general auditory sensitivity or acoustic behavior.

  3. Identifying blue whiting (Micromesistius poutassou) stock structure in the Northeast Atlantic by otolith shape analysis

    DEFF Research Database (Denmark)

    Mahe, Kélig; Oudard, Clémence; Mille, Tiphaine;

    2016-01-01

    Information on stock identification and spatial stock structure provide a basis for understanding fish population dynamics and improving fisheries management. In this study, otolith shape analysis was used to study the stock structure of blue whiting (Micromesistius poutassou) in the northeast At...

  4. Marking pike fry otoliths with alizarin complexone and strontium : an evaluation of methods

    DEFF Research Database (Denmark)

    Skov, Christian; Grønkjær, P.; Nielsen, C.

    2001-01-01

    Laboratory experiments demonstrated that both alizarin complexone and strontium are useful in mass marking of pike Esox lucius fry otoliths. Visual detection of alizarin complexone marks was considered more reliable than the quantitative analysis of strontium for differentiating marked and unmarked...

  5. Otoliths in situ from Sarmatian (Middle Miocene) fishes of the Paratethys. Part II

    DEFF Research Database (Denmark)

    Schwarzhans, Werner; Carnevale, Giorgio; Bratishko, Andriy;

    2016-01-01

    previously described by Fedotov (1976). The new data allow further synonymization of otolith-based species, such as P. insectus (Weiler 1943) and possibly also P. irregularis (Gaemers 1973). Moreover, Properca sabbai Pauca 1929 is removed from the faunal list of Sarmatian fishes in the Paratethys. Kner...

  6. Use of an otolith-deficient mutant in studies of fish behavior under microgravity

    Science.gov (United States)

    Ijiri, K.; Mizuno, R.; Eguchi, H.

    In Medaka (Oryzias latipes ), fish of a mutant strain (ha strain) had a malfunction in otolith-vestibular system. The phenotype is expressed when the fish have this recessive gene h a) in a homozygous fashion, and the gene is autosomal. Their( difference from the normal fish was first recognizable in their embryonic stages, with abnormally larger ear vesicles and absence of otoliths called Lapillus inside the vesicles. The time-course study was carried out for the subsequent development of their otoliths. X ray phot ographs of the fish revealed that some adult fish of ha- strain still lack a pair of Lapillus, which mainly serve in sensing the direction of gravity, while others have formed the otoliths partially or completely. Changing the light direction within each day, the ha mutant fish were reared from hatching to young fish. The fish treated showed less dependence on gravity even at the age of 50 days or more. Parabolic flight experiments were carried out to observe the fish behavior under microgravity for ha strain.

  7. Experimental Evaluation of Stable Isotope Fractionation in Fish Muscle and Otoliths

    Science.gov (United States)

    We investigated an unresolved question in the use of stable isotopes to determine diet and trophic position of fish using both muscle and otoliths. We determined: i) the degree of fractionation of δ13C and δ15N between diet and muscle, and assessed if fractionation was consistent...

  8. Ocean acidification alters the otoliths of a pantropical fish species with implications for sensory function.

    Science.gov (United States)

    Bignami, Sean; Enochs, Ian C; Manzello, Derek P; Sponaugle, Su; Cowen, Robert K

    2013-04-30

    Ocean acidification affects a wide diversity of marine organisms and is of particular concern for vulnerable larval stages critical to population replenishment and connectivity. Whereas it is well known that ocean acidification will negatively affect a range of calcareous taxa, the study of fishes is more limited in both depth of understanding and diversity of study species. We used new 3D microcomputed tomography to conduct in situ analysis of the impact of ocean acidification on otolith (ear stone) size and density of larval cobia (Rachycentron canadum), a large, economically important, pantropical fish species that shares many life history traits with a diversity of high-value, tropical pelagic fishes. We show that 2,100 μatm partial pressure of carbon dioxide (pCO2) significantly increased not only otolith size (up to 49% greater volume and 58% greater relative mass) but also otolith density (6% higher). Estimated relative mass in 800 μatm pCO2 treatments was 14% greater, and there was a similar but nonsignificant trend for otolith size. Using a modeling approach, we demonstrate that these changes could affect auditory sensitivity including a ∼50% increase in hearing range at 2,100 μatm pCO2, which may alter the perception of auditory information by larval cobia in a high-CO2 ocean. Our results indicate that ocean acidification has a graded effect on cobia otoliths, with the potential to substantially influence the dispersal, survival, and recruitment of a pelagic fish species. These results have important implications for population maintenance/replenishment, connectivity, and conservation efforts for other valuable fish stocks that are already being deleteriously impacted by overfishing.

  9. Life history of the Small Sandeel, Ammodytes tobianus, inferred from otolith microchemistry. A methodological approach

    Science.gov (United States)

    Laugier, F.; Feunteun, E.; Pecheyran, C.; Carpentier, A.

    2015-11-01

    Knowledge of life history and connectivity between essential ecological habitats are relevant for conservation and management of species and some natural tracers could be used to study the lifecycles of small or short-lived marine fishes. Although sandeels are central in marine food webs and are key species, there is incomplete knowledge about population mixing and migration patterns. For the first time the use of the otolith microchemistry on sandeel species is evaluated in the case of the Small Sandeel. Variations in microchemical fingerprints of 13 trace elements are performed with a Femtosecond LA-ICPM from the core to the margin of sagittal otolith and are compared within and between otoliths extracted from 34 fishes sampled in three different sites along the coast of the south-western English Channel in France. Firstly, preliminary investigations on the validity of the method revealed that Mg/Ca was the only ratio significantly dependant on fish ontogeny and sampling season. Secondly, the Mn/Ca, Zn/Ca, and Cu/Ca ratios enabled us to significantly discriminate among sampling sites. Thirdly, microchemical fingerprints of each life stage varied significantly among sampling sites but not within them, suggesting high site fidelity over relatively short distances. Finally, the fingerprints of all life stages were significantly different from those of the larval and metamorphosis stages. The otolith microchemistry could detect change of signature relative to the shift from a pelagic behaviour to a resident bentho-pelagic behaviour during the middle of the juvenile stage in Small Sandeels. Hence, analysis of trace element fingerprints in otoliths appears to be a valuable method to further studies on ontogenic habitat change, population mixing and variation of life history and be helpful for the management at local or regional scales of short-lived species such as those belonging to other Ammodytidae.

  10. Using otolith chemical and structural analysis to investigate reservoir habitat use by juvenile Chinook salmon Oncorhynchus tshawytscha.

    Science.gov (United States)

    Bourret, S L; Kennedy, B P; Caudill, C C; Chittaro, P M

    2014-11-01

    Isotopic composition of (87) Sr:(86) Sr and natural elemental tracers (Sr, Ba, Mg, Mn and Ca) were quantified from otoliths in juvenile and adult Chinook salmon Oncorhynchus tshawytscha to assess the ability of otolith microchemistry and microstructure to reconstruct juvenile O. tshawytscha rearing habitat and growth. Daily increments were measured to assess relative growth between natal rearing habitats. Otolith microchemistry was able to resolve juvenile habitat use between reservoir and natal tributary rearing habitats (within headwater basins), but not among catchments. Results suggest that 90% (n = 18) of sampled non-hatchery adults returning to the Middle Fork Willamette River were reared in a reservoir and 10% (n = 2) in natal tributary habitat upstream from the reservoir. Juveniles collected in reservoirs had higher growth rates than juveniles reared in natal streams. The results demonstrate the utility of otolith microchemistry and microstructure to distinguish among rearing habitats, including habitats in highly altered systems. PMID:25229130

  11. Torsional vestibulo-ocular reflex measurements for identifying otolith asymmetries possibly related to space motion sickness susceptibility

    Science.gov (United States)

    Peterka, Robert J.

    Recent studies by Diamond and Markham 1,2 have identified significant correlations between space motion sickness susceptibility and measures of disconjugate torsional eye movements recorded during parabolic flights. These results support an earlier proposal by von Baumgarten and Thümler 3 which hypothesized that an asymmetry of otolith function between the two ears is the cause of space motion sickness. It may be possible to devise experiments that can be performed in the 1 g environment on earth that could identify and quantify the presence of asymmetric otolith function. This paper summarizes the known physiological and anatomical properties of the otolith organs and the properties of the torsional vestibulo-ocular reflex which are relevant to the design of a stimulus to identify otolith asymmetries. A specific stimulus which takes advantage of these properties is proposed.

  12. Testing the vestibular-ocular reflexes: abnormalities of the otolith contribution in patients with neuro-otological disease.

    OpenAIRE

    Barratt, H; Bronstein, A. M.; Gresty, M A

    1987-01-01

    Conventional vestibular rotation testing with the head centered on the axis stimulates the semicircular canals evoking compensatory eye movements. If the head is placed forwards of the axis in an eccentric position the otoliths are also stimulated by a tangential linear acceleration acting laterally to the skull. In normal subjects the additional otolithic stimulus evokes compensatory eye movements with a higher gain than with head centred, particularly for high frequency (greater than 0.1 Hz...

  13. Temporal stability of otolith elemental fingerprints discriminates among lagoon nursery habitats

    Science.gov (United States)

    Tournois, Jennifer; Ferraton, Franck; Velez, Laure; McKenzie, David J.; Aliaume, Catherine; Mercier, Lény; Darnaude, Audrey M.

    2013-10-01

    The chemical composition of fish otoliths reflects that of the water masses that they inhabit. Otolith elemental compositions can, therefore, be used as natural tags to discriminate among habitats. However, for retrospective habitat identification to be valid and reliable for any adult, irrespective of its age, significant differences in environmental conditions, and therefore otolith signatures, must be temporally stable within each habitat, otherwise connectivity studies have to be carried out by matching year-classes to the corresponding annual fingerprints. This study investigated how various different combinations of chemical elements in otoliths could distinguish, over three separate years, between four coastal lagoon habitats used annually as nurseries by gilthead sea bream (Sparus aurata L.) in the Gulf of Lions (NW Mediterranean). A series of nine elements were measured in otoliths of 301 S. aurata juveniles collected in the four lagoons in 2008, 2010 and 2011. Percentages of correct re-assignment of juveniles to their lagoon of origin were calculated with the Random Forest classification method, considering every possible combination of elements. This revealed both spatial and temporal variations in accuracy of habitat identification, with correct re-assignment to each lagoon ranging from 44 to 99% depending on the year and the lagoon. There were also annual differences in the combination of elements that provided the best discrimination among the lagoons. Despite this, when the data from the three years were pooled, a combination of eight elements (B, Ba, Cu, Li, Mg, Rb, Sr and Y) provided greater than 70% correct re-assignment to each single lagoon, with a multi-annual global accuracy of 79%. When considering the years separately, discrimination accuracy with these elemental fingerprints was above 90% for 2008 and 2010. It decreased to 61% in 2011, when unusually heavy rainfall occurred, which presumably reduced chemical differences among several of the

  14. Effects of extreme habitat conditions on otolith morphology: a case study on extremophile live bearing fishes (Poecilia mexicana, P. sulphuraria).

    Science.gov (United States)

    Schulz-Mirbach, Tanja; Riesch, Rüdiger; García de León, Francisco J; Plath, Martin

    2011-12-01

    Our study was designed to evaluate if, and to what extent, restrictive environmental conditions affect otolith morphology. As a model, we chose two extremophile livebearing fishes: (i) Poecilia mexicana, a widespread species in various Mexican freshwater habitats, with locally adapted populations thriving in habitats characterized by the presence of one (or both) of the natural stressors hydrogen sulphide and darkness, and (ii) the closely related Poecilia sulphuraria living in a highly sulphidic habitat (Baños del Azufre). All three otolith types (lapilli, sagittae, and asterisci) of P. mexicana showed a decrease in size ranging from the non-sulphidic cave habitat (Cueva Luna Azufre), to non-sulphidic surface habitats, to the sulphidic cave (Cueva del Azufre), to sulphidic surface habitats (El Azufre), to P. sulphuraria. Although we found a distinct differentiation between ecotypes with respect to their otolith morphology, no clear-cut pattern of trait evolution along the two ecological gradients was discernible. Otoliths from extremophiles captured in the wild revealed only slight similarities to aberrant otoliths found in captive-bred fish. We therefore hypothesize that extremophile fishes have developed coping mechanisms enabling them to avoid aberrant otolith growth - an otherwise common phenomenon in fishes reared under stressful conditions.

  15. Texture and nano-scale internal microstructure of otoliths in the Atlantic molly, Poecilia mexicana: a high-resolution EBSD study.

    Science.gov (United States)

    Schulz-Mirbach, T; Götz, A; Griesshaber, E; Plath, M; Schmahl, W W

    2013-08-01

    Otoliths of modern bony fishes are massive polycrystalline structures consisting mainly of calcium carbonate (primarily aragonite), and 1-10% organic residuals. Unlike other biomineralisates like shells, teeth and bones, they are not optimized for mechanical loads but serve the senses of hearing and balance in the inner ear. We examined internal structural variation of otoliths through microstructural and texture analyses. Our study applied the electron backscattered diffraction technique (EBSD) to whole sections of saccular otoliths on cave- and surface-dwelling fish. Application of high spatial resolution EBSD on otoliths of the livebearing fish Poecilia mexicana allowed for an investigation of crystal orientation despite the small size (<150 nm) of aragonite crystallites. Crystallites at the rims of otoliths had a higher structural organization than those situated near the center, where no dominant orientation pattern was discernible. Moreover, the medial (sulcal) face of otoliths, which makes contact with the sensory epithelium, was more structured than the lateral (antisulcal) face.

  16. Bone conducted vibration selectively activates irregular primary otolithic vestibular neurons in the guinea pig.

    Science.gov (United States)

    Curthoys, Ian S; Kim, Juno; McPhedran, Samara K; Camp, Aaron J

    2006-11-01

    The main objective of this study was to determine whether bone-conducted vibration (BCV) is equally effective in activating both semicircular canal and otolith afferents in the guinea pig or whether there is preferential activation of one of these classes of vestibular afferents. To answer this question a large number (346) of single primary vestibular neurons were recorded extracellularly in anesthetized guinea pigs and were identified by their location in the vestibular nerve and classed as regular or irregular on the basis of the variability of their spontaneous discharge. If a neuron responded to angular acceleration it was classed as a semicircular canal neuron, if it responded to maintained roll or pitch tilts it was classified as an otolith neuron. Each neuron was then tested by BCV stimuli-either clicks, continuous pure tones (200-1,500 Hz) or short tone bursts (500 Hz lasting 7 ms)-delivered by a B-71 clinical bone-conduction oscillator cemented to the guinea pig's skull. All stimulus intensities were referred to that animal's own auditory brainstem response (ABR) threshold to BCV clicks, and the maximum intensity used was within the animal's physiological range and was usually around 70 dB above BCV threshold. In addition two sensitive single axis linear accelerometers cemented to the skull gave absolute values of the stimulus acceleration in the rostro-caudal direction. The criterion for a neuron being classed as activated was an audible, stimulus-locked increase in firing rate (a 10% change was easily detectable) in response to the BCV stimulus. At the stimulus levels used in this study, semicircular canal neurons, both regular and irregular, were insensitive to BCV stimuli and very few responded: only nine of 189 semicircular canal neurons tested (4.7%) showed a detectable increase in firing in response to BCV stimuli up to the maximum 2 V peak-to-peak level we delivered to the B-71 oscillator (which produced a peak-to-peak skull acceleration of around

  17. Modelling the mixing of herring stocks between the Baltic and the North Sea from otolith data

    DEFF Research Database (Denmark)

    Ulrich, Clara; Post, Søren Lorentzen; Worsøe Clausen, Lotte;

    2012-01-01

    Herring catches in the western Baltic, Kattegat and Skagerrak consist of a mixture of stocks, mainly North Sea autumn spawners (NSAS) and western Baltic spring spawners (WBSS), which is managed through a single TAC. Catches of these two stocks are split using otolith microstructures from Danish and...... Swedish commercial landings and surveys samples for the purpose of stock assessment. But the split estimates from sampling data are highly variable and noisy. Better understanding of the migration and exploitation patterns involved could therefore potentially improve the stock assessment as well as...... provide solutions to the complex management of this mix. The stock‐specific seasonal trends in distribution of the two main stocks from otolith data were analysed using a generalized linear mixed model (GLMM) of stock composition. The results show a clear seasonal and age‐related pattern and are...

  18. Factors determining variations in otolith microincrement width of demersal juvenile Baltic cod Gadus morhua

    DEFF Research Database (Denmark)

    Hüssy, Karin; Mosegaard, Henrik; Hinrichsen, H.H.;

    2003-01-01

    Pelagic and demersal juvenile Baltic cod Gadus morhua L. were collected on the slope and the top of Rønne bank in the Baltic Sea during 2 cruises in November and December 1998. The objective of this study was to evaluate distinct changes in otolith increment width observed in demersal juveniles b......, performed vertical migrations during the second interval, and stayed in association with the seafloor in the subsequent interval, corresponding to the time after the breakdown of the thermocline....

  19. Analysis of matrix proteins of otolith in upside-down catfish

    Science.gov (United States)

    Ohnishi, K.; Okamoto, N.; Takahashi, A.; Ohnishi, T.

    We have previously suggested that the calcium density of the otolith in upside-down swimming Synodontis nigriventris is lower than that in upside-up swimming Synodontis multipunctatus Biol Space Sci 2002 In this study we examined EDTA-soluble matrix proteins of otolith in the utricle of the catfish S nigriventris S multipunctatus and upside-up swimming Synodontis brichadi and goldfish Carassius auratus We detected two main bands about 55 kD and 80 kD with SDS-PAGE in the 3 species of the catfish In cntrast goldfish had the about 55 kD band alone The band of about 80 kD was consisted of two sub-bands a lighter and a heavier band A lighter band was observed in S brichadi and a heavier band was observed in S nigriventris S multipunctatus had the both bands Furthermore mass spectrometric analysis showed there were some proteins of molecular weight under 14 kD The molecular weights of the proteins were different among the fishes These results suggest that many different kinds of matrix protein may cause different degree of calcification in otolith formation

  20. Temporal variability in estuarine fish otolith elemental fingerprints: Implications for connectivity assessments

    Science.gov (United States)

    Reis-Santos, Patrick; Gillanders, Bronwyn M.; Tanner, Susanne E.; Vasconcelos, Rita P.; Elsdon, Travis S.; Cabral, Henrique N.

    2012-10-01

    The chemical composition of fish otoliths can provide valuable information for determining the nursery value of estuaries to adult populations of coastal fishes. However, understanding temporal variation in elemental fingerprints at different scales is important as it can potentially confound spatial discrimination among estuaries. Otolith elemental ratios (Li:Ca, Mg:Ca, Mn:Ca, Cu:Ca, Sr:Ca, Ba:Ca and Pb:Ca) of Platichthys flesus and Dicentrarchus labrax, from several estuaries along the Portuguese coast in two years and three seasons (spring, summer and autumn) within a year, were determined via Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Elemental fingerprints varied significantly among years and seasons within a year but we achieved accurate classifications of juvenile fish to estuarine nursery of origin (77-96% overall cross-validated accuracy). Although elemental fingerprints were year-specific, variation among seasons did not hinder spatial discrimination. Estuarine fingerprints of pooled seasonal data were representative of the entire juvenile year class and attained high discrimination (77% and 80% overall cross-validated accuracy for flounder and sea bass, respectively). Incorporating seasonal variation resulted in up to an 11% increase in correct classification of individual estuaries, in comparison to seasons where accuracies were lowest. Overall, understanding the implications of temporal variations in otolith chemistry for spatial discrimination is key to establish baseline data for connectivity studies.

  1. Lake trout otolith chronologies as multidecadal indicators of high-latitude freshwater ecosystems

    Science.gov (United States)

    Black, B.A.; Von Biela, V.R.; Zimmerman, C.E.; Brown, Randy J.

    2013-01-01

    High-latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments. To address this issue, dendrochronology (tree-ring analysis) techniques were applied to growth-increment widths in otoliths from lake trout (Salvelinus namaycush) from the Chandler Lake system, Alaska (68.23°N, 152.70°W). All otoliths were collected in 1987 and exhibited highly synchronous patterns in growth-increment width. Increments were dated, the widths were measured, and age-related growth declines were removed using standard dendrochronology techniques. The detrended time series were averaged to generate an annually resolved chronology, which continuously spanned 1964–1984. The chronology positively and linearly correlated with August air temperature over the 22-year interval (p < 0.01), indicating that warmer summers were beneficial for growth, perhaps by increasing fish metabolic rate or lake productivity. Given the broad distribution of lake trout within North America, this study suggests that otolith chronologies could be used to examine responses between freshwater ecosystems and environmental variability across a range of temporal and spatial scales.

  2. Juvenile life history of NE Atlantic orange roughy from otolith stable isotopes

    Science.gov (United States)

    Shephard, Samuel; Trueman, Clive; Rickaby, Rosalind; Rogan, Emer

    2007-08-01

    Otoliths of pre-recruit orange roughy ( Hoplostethus atlanticus) were sampled from different deep-water habitats ('flat' and 'hill') and areas (north and south) on the Porcupine Bank. Age-based profiles for stable isotopes of carbon (δ 13C) and oxygen (δ 18O) in these otoliths were developed, which provide a fish life-history record of water depth and metabolic activity. These profiles were consistent among all individuals implying endogenous (ontogenic) influences on the pattern. The data indicate that post-larval orange roughy are mesopelagic active foragers, early juvenile fish move into a low energy deep-demersal phase, and older pre-recruit orange roughy assume the habitat depth and metabolic rate typical of adults. Comparison of otolith stable isotope profiles among areas and habitats on the Porcupine Bank suggest that juvenile orange roughy from South 'hill' and 'flat' habitats experience differing temperature and metabolic status at certain life stages. This may reflect oceanographic and ecological divergence between the two environments and suggests fine-scale population structure that may reduce resilience to exploitation.

  3. UREA/ammonium ion removal system for the orbiting frog otolith experiment. [ion exchange resins for water treatment during space missions

    Science.gov (United States)

    Schulz, J. R.; Anselmi, R. T.

    1976-01-01

    The feasibility of using free urease enzyme and ANGC-101 ion exchange resin to remove urea and ammonium ion for space system waste water applications was studied. Specifically examined is the prevention of urea and ammonia toxicity in a 30-day Orbiting Frog Otolith (OFO) flight experiment. It is shown that free urease enzyme used in conjunction with ANGC-101 ion-exchange resin and pH control can control urea and amonium ion concentration in unbuffered recirculating water. In addition, the resin does not adversely effect the bullfrogs by lowering the concentration of cations below critical minimum levels. Further investigations on bioburden control, frog waste excretion on an OFO diet, a trade-off analysis of methods of automating the urea/ammonium ion removal system and fabrication and test of a semiautomated breadboard were recommended as continuing efforts. Photographs of test equipment and test animals are shown.

  4. Three-dimensional organization of otolith-ocular reflexes in rhesus monkeys. II. Inertial detection of angular velocity

    Science.gov (United States)

    Angelaki, D. E.; Hess, B. J.

    1996-01-01

    1. The dynamic contribution of otolith signals to three-dimensional angular vestibuloocular reflex (VOR) was studied during off-vertical axis rotations in rhesus monkeys. In an attempt to separate response components to head velocity from those to head position relative to gravity during low-frequency sinusoidal oscillations, large oscillation amplitudes were chosen such that peak-to-peak head displacements exceeded 360 degrees. Because the waveforms of head position and velocity differed in shape and frequency content, the particular head position and angular velocity sensitivity of otolith-ocular responses could be independently assessed. 2. During both constant velocity rotation and low-frequency sinusoidal oscillations, the otolith system generated two different types of oculomotor responses: 1) modulation of three-dimensional eye position and/or eye velocity as a function of head position relative to gravity, as presented in the preceding paper, and 2) slow-phase eye velocity as a function of head angular velocity. These two types of otolith-ocular responses have been analyzed separately. In this paper we focus on the angular velocity responses of the otolith system. 3. During constant velocity off-vertical axis rotations, a steady-state nystagmus was elicited that was maintained throughout rotation. During low-frequency sinusoidal off-vertical axis oscillations, dynamic otolith stimulation resulted primarily in a reduction of phase leads that characterize low-frequency VOR during earth-vertical axis rotations. Both of these effects are the result of an internally generated head angular velocity signal of otolithic origin that is coupled through a low-pass filter to the VOR. No change in either VOR gain or phase was observed at stimulus frequencies larger than 0.1 Hz. 4. The dynamic otolith contribution to low-frequency angular VOR exhibited three-dimensional response characteristics with some quantitative differences in the different response components. For

  5. Using otolith weight to predict the age of Pennahia macrocephalus in the mouth of the Beibu Gulf

    Institute of Scientific and Technical Information of China (English)

    YAN Yunrong; WU Yanfang; LU Huosheng; LI Zhonglu; JIN Xianshi

    2009-01-01

    The relation between otolith weight (OW) and the age of marine fish is studied. A total of 222 individuals of bighead white croaker, Pennahia macrocephalus were sampled seasonally in the mouth of the Beibu Gulf, the South China Sea, in 2007. Since there are no significant differences in sagittal OW between otolith in pairs (P≧>0.05), the undamaged left sagittal otolith is used for age determination. The highest correlations among standard length, OW and fish ages are confirmned by linear, exponential and multinomial regression. Results show that sagittal OW overlaps only occasionally among age groups, and to individuals with similar standard length, the older and slower-growing fish has a heavier otolith because of the continued otolith material deposition. There are differences in sagittal OW among different age groups and significant positive linear relationship with age (P<0.05). The age readings can be verified by plotting the sagittal OW versus the standard length for age groups, and the individuals with similar standard length but in different ages can be separated by sagittal OW frequency analysis. Mostly, the predicted ages using the regression between sagittai OW and ages are closed to the observed ages by counting annulus on scale. It indicates that the sagittal OW analysis is a useful technique for validating the accuracy of age determination by annuli counts, especially for individuals of similar size. Furthermore,the technique is applied for Pennahia macrocephalus with discussion in this paper.

  6. Up-Down Chair: A novel mechatronic device to assess otolith function in patients with vestibular disorders.

    Science.gov (United States)

    Luciani, Lorenzo Bassi; Martelli, Dario; Monaco, Vito; Genovese, Vincenzo; Micera, Silvestro

    2016-03-01

    This paper describes a novel mechatronic platform, named "Up-Down Chair" (UDC), aimed at investigating otolith function in patients with vestibular disorders. The UDC was designed to provide a wide range of repeatable and controllable vertical oscillations of the head whose kinematic features match those encountered during daily activities. The following parameters were assessed to characterize the performance of the UDC: accordance between expected and measured kinematics in both loaded and unloaded conditions; Dynamic Visual Acuity (DVA) of a group of 15 healthy subjects who were asked to identify a set of Snellen optotypes while being repeatedly moved at different perturbation intensities. Results revealed a good agreement between expected and measured kinematic patterns, and excellent reliability of DVA assessed across enrolled participants. In addition, we observed that the proposed paradigm was effective in inducing oscillopsia in enrolled subjects and that the frequency of the oscillation significantly induced blurred vision during the experimental tests. The UDC appears to be usable as a complementary vestibular clinical test to investigate the effects of therapeutic treatments while applying a wide range of physiological stimuli compatible with those encountered during daily activities. PMID:26806396

  7. Ecological study of the migration of eel by synchrotron radiation induced X-ray fluorescence imaging of otoliths

    International Nuclear Information System (INIS)

    Synchrotron radiation-induced X-ray fluorescence imaging is suitable for determining the distribution of trace elements in fish otoliths. The Sr/Ca ratio in an otolith is an indicator of salinity changes and can be used to clarify the migration history of the eel, a catadromous fish. The otoliths of eel collected from the Tone and Elbe rivers exhibited a typical catadromous pattern, i.e. birth and breeding occurred in the ocean, but the remainder of their lives was spent in fresh water. In contrast, eels from the East China Sea and North Sea exhibited an unusual sea-locking phenomenon, as they appear to have remained in marine habitats throughout their lives. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  8. Ecological study of the migration of eel by synchrotron radiation induced X ray fluorescence imaging of otoliths

    Science.gov (United States)

    Nakai, Izumi; Iwata, Raita; Tsukamoto, Katsumi

    1999-01-01

    Synchrotron radiation-induced X-ray fluorescence imaging is suitable for determining the distribution of trace elements in fish otoliths. The Sr/Ca ratio in an otolith is an indicator of salinity changes and can be used to clarify the migration history of the eel, a catadromous fish. The otoliths of eel collected from the Tone and Elbe rivers exhibited a typical catadromous pattern, i.e. birth and breeding occurred in the ocean, but the remainder of their lives was spent in fresh water. In contrast, eels from the East China Sea and North Sea exhibited an unusual sea-locking phenomenon, as they appear to have remained in marine habitats throughout their lives.

  9. Non-invasive assessment of otolith formation during development of the Japanese red-bellied newt, Cynops pyrrhogaster

    Science.gov (United States)

    Koike, H.; Nakamura, K.; Nishimura, K.; Kashima, I.; Wiederhold, M. L.; Asashima, M.

    1995-01-01

    Pre-mated adult female newts and embryos have been flown on the International Microgravity Laboratory-2 (IML-2) Space Shuttle flight in 1994 (Wiederhold et al., 1992b). With the specimens available from this flight, the calcification of otoliths, ulna, radius and backbone of the flown larvae and adult newts were analyzed. The experiments presented here studied the development of the otoliths on the ground. Otoliths of living newts, from embryo to adult, were observed in situ with the application of a new X-ray and bio-imaging analyzer system. For the establishment of this method, newts at different developmental stages were used. An imaging plate temporarily stores the X-ray energy pattern at the bio-imaging analyzer. A latent image on the imaging plate was transformed into a digital time series signal with an image reader. Acquired digital information was computed with the image processor. The processed information was recorded on film with an image recorder, in order to visualize it on an enlargement computed radiograph. To analyze development of the otoliths, photo-stimulated luminescence level was detected by an image analyzer, using transmitted X-ray photons. A single clump of otoconia could first be seen at stage 33. Stage-36 embryos first have distinguishable otoliths, with the utricle in front and saccule behind. Our results show that this X-ray method detects the otoliths equally as well as sectioning. In the newt, the mandibular/maxillary bone formed before the spine. It is suspected that for the newt embryo, living in water, feeding becomes necessary prior to support of the body.

  10. The great melting pot. Common sole population connectivity assessed by otolith and water fingerprints.

    Science.gov (United States)

    Morat, Fabien; Letourneur, Yves; Dierking, Jan; Pécheyran, Christophe; Bareille, Gilles; Blamart, Dominique; Harmelin-Vivien, Mireille

    2014-01-01

    Quantifying the scale and importance of individual dispersion between populations and life stages is a key challenge in marine ecology. The common sole (Solea solea), an important commercial flatfish in the North Sea, Atlantic Ocean and the Mediterranean Sea, has a marine pelagic larval stage, a benthic juvenile stage in coastal nurseries (lagoons, estuaries or shallow marine areas) and a benthic adult stage in deeper marine waters on the continental shelf. To date, the ecological connectivity among these life stages has been little assessed in the Mediterranean. Here, such an assessment is provided for the first time for the Gulf of Lions, NW Mediterranean, based on a dataset on otolith microchemistry and stable isotopic composition as indicators of the water masses inhabited by individual fish. Specifically, otolith Ba/Ca and Sr/Ca profiles, and δ(13)C and δ(18)O values of adults collected in four areas of the Gulf of Lions were compared with those of young-of-the-year collected in different coastal nurseries. Results showed that a high proportion of adults (>46%) were influenced by river inputs during their larval stage. Furthermore Sr/Ca ratios and the otolith length at one year of age revealed that most adults (∼70%) spent their juvenile stage in nurseries with high salinity, whereas the remainder used brackish environments. In total, data were consistent with the use of six nursery types, three with high salinity (marine areas and two types of highly saline lagoons) and three brackish (coastal areas near river mouths, and two types of brackish environments), all of which contributed to the replenishment of adult populations. These finding implicated panmixia in sole population in the Gulf of Lions and claimed for a habitat integrated management of fisheries.

  11. Fish otolith geochemistry, environmental conditions and human occupation at Lake Mungo, Australia

    Science.gov (United States)

    Long, Kelsie; Stern, Nicola; Williams, Ian S.; Kinsley, Les; Wood, Rachel; Sporcic, Katarina; Smith, Tegan; Fallon, Stewart; Kokkonen, Harri; Moffat, Ian; Grün, Rainer

    2014-03-01

    Fish otoliths from the Willandra Lakes Region World Heritage Area (south-western New South Wales, Australia) have been analysed for oxygen isotopes and trace elements using in situ techniques, and dated by radiocarbon. The study focused on the lunettes of Lake Mungo, an overflow lake that only filled during flooding events and emptied by evaporation, and Lake Mulurulu, which was part of the running Willandra Creek system. Samples were collected from two different contexts: from hearths directly associated with human activity, and isolated surface finds. AMS radiocarbon dating constrains the human activity documented by five different hearths to a time span of less than 240 years around 19,350 cal. BP. These hearths were constructed in aeolian sediments with alternating clay and sand layers, indicative of fluctuating lake levels and occasional drying out. The geochemistry of the otoliths confirms this scenario, with shifts in Sr/Ca and Ba/Ca marking the entry of the fish into Lake Mungo several years before their death, and a subsequent increase in the δ18O by ˜4‰ indicating increasing evaporation of the lake. During sustained lake-full conditions there are considerably fewer traces of human presence. It seems that the evaporating Lake Mungo attracted people to harvest fish that might have become sluggish through oxygen starvation in an increasingly saline water body (easy prey hypothesis). In contrast, surface finds have a much wider range in radiocarbon age as a result of reworking, and do not necessarily indicate evaporative conditions, as shown by comparison with otoliths from upstream Lake Mulurulu.

  12. Otolith shape analysis as a tool for stock identification of the southern blue whiting, Micromesistius australis

    Directory of Open Access Journals (Sweden)

    Javier Leguá

    2013-07-01

    Full Text Available The southern blue whiting, Micromesistius australis (Norman, 1937, is an important demersal resource associated with the slope and continental shelf of southern Chile, Argentina and the Malvinas/Falkland Islands. Recent studies have reported schools of adult fish from Atlantic waters migrating along the southern Chilean coast in mid-winter, moving northwards to spawn in August (47°-51°S, and then returning to Atlantic waters, presumably to feed. The migratory pattern suggests the presence of one or more stock units associated with the South American coast. In the present study, "otolith morphometry" is used to determine the stock structure of M. australis based on applications of basic size descriptors (SDs (area, perimeter and otolith size, shape indices (SIs (circularity, squareness, shape factor, roundness, ellipticity, and normalised elliptical Fourier descriptors (NEFDs. Samples were collected during the winter and spring of 2010, during the reproductive period, in the economic zone of southern Chile (36°-57°S, in the Pacific Ocean and around the Falkland Islands economic zone (50°-52°S in the Atlantic Ocean. Analyses were conducted to include the effects of size, sex and age. A stepwise canonical discriminant analysis showed that fish were successfully discriminated with SDs, SIs and NEFDs. In this analysis, 86.4% and 70.1% of the fish were correctly classified as belonging to the Atlantic and Pacific stocks, respectively. A multivariate analysis of variance showed that the mean values of the NEFDs, SDs, and SIs did not vary significantly between sexes within areas (P > 0.05, but varied significantly between the Pacific and Atlantic oceans (P < 0.05. These results highlighted that otolith shape analysis can be a useful tool to evaluate the potential level of mixing in feeding areas where both stocks, the Pacific and Atlantic units, are expected to co-occur.

  13. Natural growth, otolith shape and diet analyses of Odontesthes nigricans Richardson (Atherinopsidae) from southern Patagonia

    Science.gov (United States)

    Lattuca, M. E.; Lozano, I. E.; Brown, D. R.; Renzi, M.; Luizon, C. A.

    2015-12-01

    Age and growth, otolith shape and diet of Odontesthes nigricans were analysed in order to provide an insight into the life history of the species and furthermore, to assess their possible use as a tool for discriminating silverside populations from the South Atlantic Ocean (Punta María) and Beagle Channel waters (Varela Bay). The age and growth analysis was performed by counting daily increments and annual marks in sagittae otoliths. Length-at-age data of individuals Gompertz model (SLt = 6.22 exp 2.45 [1-exp (-0.02t)]), which provided an excellent description of the pattern of daily growth for O. nigricans juveniles from Varela Bay. The spawning period was also assessed through back-calculation of hatching dates and it extended from November to February. The count of annual marks in larger individuals identified 7 year classes (0+ to 6+) in Varela Bay and 6 year classes (0+ to 5+) in Punta María. The von Bertalanffy growth model explained more than 95% of the growth patterns observed in O. nigricans from Varela Bay (SLt = 245.49 [1 - exp -0.24(t+0.46)]) and Punta María (SLt = 345.09 [1 - exp -0.15(t+0.31)]). Particularly, k and SL∞ varied significantly between sampling sites; reaching Punta María a larger SL∞ value with a lower k. Otolith shape variation was also explored using elliptical Fourier analysis and it showed significant differences between Varela Bay and Punta María populations. Furthermore, gut content analysis characterized O. nigricans as an invertebrate predator, being benthic organisms the most important components of its diet, which also showed significant site dependence. The use of all these analyses contributed to a holistic approach which maximized the likelihood of correctly identifying both O. nigricans populations in the southernmost limit of the species distribution.

  14. The use of otolith microstructure to estimate age in adult Atlantic cod Gadus morhua

    DEFF Research Database (Denmark)

    Hüssy, Karin; Hinrichsen, H.H.; Fey, D.P.;

    2010-01-01

    be tightly coupled to the annual cycle in environmental temperature at a depth of 30–60 m, where G. morhua predominantly reside. Between 135 and 200 increments occurred within the different zones, with a non-significant trend towards lower increment numbers and widths with distance from the primary...... primordium of the otolith. Increment formation apparently ceased at temperatures <5–6° C, but growth during the cold months corresponded closely with estimated growth rates. The increment patterns seemed to reflect annual cycles in environmental temperature, and the count of the increment cycles may thus be...... a promising tool for the determination of the true age of Baltic G. morhua....

  15. Partial migration of grey mullet (Mugil cephalus) on Australia's east coast revealed by otolith chemistry.

    Science.gov (United States)

    Fowler, Ashley M; Smith, Shannen M; Booth, David J; Stewart, John

    2016-08-01

    Partial migration affects the ecology and evolution of animal populations, and is an important consideration for the management of harvested species, yet the phenomenon is understudied in fish. We provide the first insights into partially diadromous migration of grey mullet (Mugil cephalus) in Australia by examining the otolith chemistry of old individuals (aged 7-10 years) from two regions on the east coast. Strontium and Barium concentrations were measured across the otolith using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and indicated considerable diversity in migratory histories among individuals. Only 15% of individuals made repeated movements from estuaries to the marine environment, consistent with the annual spawning run in the region. The remainder either made irregular movements between salinity environments (70%), or resided in estuaries or fresh water for their entire life following the early juvenile stage (15%). The patterns are consistent with 'skipped spawning' partial migration, where a proportion of the mature population forgoes spawning each year. If confirmed, the behavior may afford the east coast population of M. cephalus some resilience to fishing pressure on the annual spawning run. PMID:27344396

  16. Listening in on the past: what can otolith δ18O values really tell us about the environmental history of fishes?

    Science.gov (United States)

    Darnaude, Audrey M; Sturrock, Anna; Trueman, Clive N; Mouillot, David; Campana, Steven E; Hunter, Ewan

    2014-01-01

    Oxygen isotope ratios from fish otoliths are used to discriminate marine stocks and reconstruct past climate, assuming that variations in otolith δ18O values closely reflect differences in temperature history of fish when accounting for salinity induced variability in water δ18O. To investigate this, we exploited the environmental and migratory data gathered from a decade using archival tags to study the behaviour of adult plaice (Pleuronectes platessa L.) in the North Sea. Based on the tag-derived monthly distributions of the fish and corresponding temperature and salinity estimates modelled across three consecutive years, we first predicted annual otolith δ18O values for three geographically discrete offshore sub-stocks, using three alternative plausible scenarios for otolith growth. Comparison of predicted vs. measured annual δ18O values demonstrated >96% correct prediction of sub-stock membership, irrespective of the otolith growth scenario. Pronounced inter-stock differences in δ18O values, notably in summer, provide a robust marker for reconstructing broad-scale plaice distribution in the North Sea. However, although largely congruent, measured and predicted annual δ18O values did not fully match [ corrected]. Small, but consistent, offsets were also observed between individual high-resolution otolith δ18O values measured during tag recording time and corresponding δ18O predictions using concomitant tag-recorded temperatures and location-specific salinity estimates. The nature of the shifts differed among sub-stocks, suggesting specific vital effects linked to variation in physiological response to temperature. Therefore, although otolith δ18O in free-ranging fish largely reflects environmental temperature and salinity, we counsel prudence when interpreting otolith δ18O data for stock discrimination or temperature reconstruction until the mechanisms underpinning otolith δ18O signature acquisition, and associated variation, are clarified.

  17. Listening in on the past: what can otolith δ18O values really tell us about the environmental history of fishes?

    Directory of Open Access Journals (Sweden)

    Audrey M Darnaude

    Full Text Available Oxygen isotope ratios from fish otoliths are used to discriminate marine stocks and reconstruct past climate, assuming that variations in otolith δ18O values closely reflect differences in temperature history of fish when accounting for salinity induced variability in water δ18O. To investigate this, we exploited the environmental and migratory data gathered from a decade using archival tags to study the behaviour of adult plaice (Pleuronectes platessa L. in the North Sea. Based on the tag-derived monthly distributions of the fish and corresponding temperature and salinity estimates modelled across three consecutive years, we first predicted annual otolith δ18O values for three geographically discrete offshore sub-stocks, using three alternative plausible scenarios for otolith growth. Comparison of predicted vs. measured annual δ18O values demonstrated >96% correct prediction of sub-stock membership, irrespective of the otolith growth scenario. Pronounced inter-stock differences in δ18O values, notably in summer, provide a robust marker for reconstructing broad-scale plaice distribution in the North Sea. However, although largely congruent, measured and predicted annual δ18O values did not fully match [ corrected]. Small, but consistent, offsets were also observed between individual high-resolution otolith δ18O values measured during tag recording time and corresponding δ18O predictions using concomitant tag-recorded temperatures and location-specific salinity estimates. The nature of the shifts differed among sub-stocks, suggesting specific vital effects linked to variation in physiological response to temperature. Therefore, although otolith δ18O in free-ranging fish largely reflects environmental temperature and salinity, we counsel prudence when interpreting otolith δ18O data for stock discrimination or temperature reconstruction until the mechanisms underpinning otolith δ18O signature acquisition, and associated variation, are

  18. Spatial and temporal variability in the otolith chemistry of the Brazilian snapper Lutjanus alexandrei from estuarine and coastal environments.

    Science.gov (United States)

    Aschenbrenner, A; Ferreira, B P; Rooker, J R

    2016-07-01

    Otolith chemistry of juvenile and adult individuals of the Brazilian snapper Lutjanus alexandrei was measured to assess the utility of natural markers for investigating individual movements. Individuals were collected over a 3-year period (2010-2012) along the north-eastern coast of Brazil from both estuarine (juvenile to sub-adult stages) and coastal (sub-adult to adult stages) areas. Six elements ((7) Li, (24) Mg, (55) Mn, (59) Co, (88) Sr and (137) Ba) were measured in sectioned otoliths of L. alexandrei using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Edge composition analysis indicated that element:Ca ratios in the otoliths of juvenile and sub-adult L. alexandrei from estuaries were not significantly different among the three consecutive years (2010, 2011 and 2012), suggesting that physicochemical conditions within the nursery area investigated were temporally stable. Similarly, apart from two elements (Ba and Co), element:Ca ratios for larger L. alexandrei inhabiting coastal waters were also similar. In contrast, otolith chemistry of similar sized L. alexandrei from estuarine and coastal areas was significantly different (based on recently accreted material). Otolith Mn:Ca and Ba:Ca were both significantly higher for L. alexandrei collected in estuaries compared to fish from adjacent coastal reefs, while the opposite trend was observed for Sr:Ca. Given the pronounced differences in otolith chemistry between estuarine and coastal areas, element:Ca transects were constructed from the core to margin of the otoliths for adults (age 7+ years) collected on reefs to determine the timing of movement (ontogenetic migration) from estuarine to coastal areas. Based on observed patterns of decline for both Mn:Ca and Ba:Ca, it appears that L. alexandrei begin the move to more coastal habitats (i.e. lower element:Ca ratios) after age 2 years. The patterns observed for this species highlight the importance of conserving connectivity between

  19. Spatial and temporal variability in the otolith chemistry of the Brazilian snapper Lutjanus alexandrei from estuarine and coastal environments.

    Science.gov (United States)

    Aschenbrenner, A; Ferreira, B P; Rooker, J R

    2016-07-01

    Otolith chemistry of juvenile and adult individuals of the Brazilian snapper Lutjanus alexandrei was measured to assess the utility of natural markers for investigating individual movements. Individuals were collected over a 3-year period (2010-2012) along the north-eastern coast of Brazil from both estuarine (juvenile to sub-adult stages) and coastal (sub-adult to adult stages) areas. Six elements ((7) Li, (24) Mg, (55) Mn, (59) Co, (88) Sr and (137) Ba) were measured in sectioned otoliths of L. alexandrei using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Edge composition analysis indicated that element:Ca ratios in the otoliths of juvenile and sub-adult L. alexandrei from estuaries were not significantly different among the three consecutive years (2010, 2011 and 2012), suggesting that physicochemical conditions within the nursery area investigated were temporally stable. Similarly, apart from two elements (Ba and Co), element:Ca ratios for larger L. alexandrei inhabiting coastal waters were also similar. In contrast, otolith chemistry of similar sized L. alexandrei from estuarine and coastal areas was significantly different (based on recently accreted material). Otolith Mn:Ca and Ba:Ca were both significantly higher for L. alexandrei collected in estuaries compared to fish from adjacent coastal reefs, while the opposite trend was observed for Sr:Ca. Given the pronounced differences in otolith chemistry between estuarine and coastal areas, element:Ca transects were constructed from the core to margin of the otoliths for adults (age 7+ years) collected on reefs to determine the timing of movement (ontogenetic migration) from estuarine to coastal areas. Based on observed patterns of decline for both Mn:Ca and Ba:Ca, it appears that L. alexandrei begin the move to more coastal habitats (i.e. lower element:Ca ratios) after age 2 years. The patterns observed for this species highlight the importance of conserving connectivity between

  20. Otolith microstructure analysis to resolve seasonal patterns of hatching and settlement in western Baltic cod

    DEFF Research Database (Denmark)

    Rehberg-Haas, Sabine; Hammer, Cornelius; Hillgruber, Nicola;

    2012-01-01

    differentiate between true annuli and secondary structures such as settlement checks. Otoliths were collected from fish off Fehmarn Island in 2008 and 2009, and were examined for macrostructural and microstructural patterns using light and scanning electron microscopy. All fish examined were age-0. Back......-calculation of hatch dates indicated hatching from April to June and from February to August in 2008 and 2009, respectively. Juveniles formed either one or two translucent rings. The first translucent ring started to form ∼3 months post-hatch and was interpreted as a settlement check, since it appeared to be a...... February and May, but were merged in those fish where settlement coincided with the seasonally formed second ring...

  1. Fine-scale oscillatory banding in otoliths from arctic charr (Salveninus alpinus) and pike (Esox lucius)

    Energy Technology Data Exchange (ETDEWEB)

    Meldrum, A. [Oak Ridge National Lab., TN (United States); Halden, N.M. [Univ. of Manitoba, Winnipeg (Canada). Dept. of Geological Sciences

    1997-12-31

    Transmission electron microscopy of otoliths from the inner ear of arctic charr and pike has revealed the presence of fine banding on the scale of several nanometers. The thickness of the bands was observed to vary in different portions of the sample, and some areas were not banded. EDS analysis could not detect chemical differences within the bands, but electron diffraction showed that the crystallographic orientation of the bands is related by a lattice mismatch. Previously, banding on the scale of 50 to 100 microns was observed by SEM in otoliths from arctic charr and was attributed to seasonal variations in growth. The fine-scale banding observed in this study, however, is unlikely to represent a daily variation. Electron diffraction from the pike samples shows that the material is composed of CaCO{sub 3} having the both the vaterite and aragonite structure, and hydrous CaCO{sub 3} was also observed. The large-scale banding previously identified by SEM was not observed in the TEM despite attempts to intersect the boundaries of the micron-sized layers. The interaction of the electron beam with the sample material was investigated by conducting several electron-irradiation experiments. The electron beam was observed to interact strongly with the sample and caused the precipitation of cubic CaO from the calcium carbonate matrix. Bright-field imaging showed the development of fine grained ({approximately} 5 nm) randomly oriented crystallites which accumulated with increasing electron dose. These initial results suggest that the precipitation of CaO is not driven by electron-beam beating. Previously, a similar phase-change phenomenon has been observed in hydroxyapatite from dental enamel. Other Ca-bearing biominerals may therefore also be expected to be sensitive to electron irradiation.

  2. Fingerprints of lagoonal life: Migration of the marine flatfish Solea solea assessed by stable isotopes and otolith microchemistry

    Science.gov (United States)

    Dierking, Jan; Morat, Fabien; Letourneur, Yves; Harmelin-Vivien, Mireille

    2012-06-01

    The commercially important marine flatfish common sole (Solea solea) facultatively uses NW Mediterranean lagoons as nurseries. To assess the imprint left by the lagoonal passage, muscle carbon (C) and nitrogen (N) isotope values of S. solea juveniles caught in Mauguio lagoon in spring (shortly after arrival from the sea) and in autumn (before the return to the sea) were compared with values of juveniles from adjacent coastal marine nurseries. In addition, in the lagoon, sole otolith stable isotope (C and oxygen (O)) and elemental (11 elements) composition in spring and autumn, and the stable isotope composition (C and N) of organic matter sources in autumn, were determined. Overall, our data indicate that a distinct lagoonal signature existed. Specifically, lagoon soles showed a strong enrichment in muscle tissue 15N (>6‰) compared to their coastal relatives, likely linked to sewage inputs (see below), and a depletion in 13C (1-2‰), indicative of higher importance of 13C depleted terrestrial POM in the lagoon compared to coastal nurseries. In addition, over the time spent in the lagoon, sole otolith δ13C and δ18O values and otolith elemental composition changed significantly. Analysis of the lagoon sole foodweb based on C and N isotopes placed sediment particulate organic matter (POM) at the base. Seagrasses, formerly common but in decline in Mauguio lagoon, played a minor role in the detritus cycle. The very strong 15N enrichment of the entire foodweb (+7 to +11‰) compared to little impacted lagoons and coastal areas testified of important human sewage inputs. Regarding the S. solea migration, the analysis of higher turnover and fast growth muscle tissue and metabolically inert and slower growth otoliths indicated that soles arrived at least several weeks prior to capture in spring, and that no migrations took place in summer. In the autumn, the high muscle δ15N value acquired in Mauguio lagoon would be a good marker of recent return to the sea, whereas

  3. Slave to the rhythm: seasonal signals in otolith microchemistry reveal age of eastern Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Hüssy, Karin; Gröger, J.; Heidemann, F.;

    2016-01-01

    Annual growth zones in cod otoliths from the eastern Baltic stock are less discrete than in other cod stocks leading to biased age reading, which recently led to a failure of age-based assessment in the eastern Baltic cod stock. In this study, we explored the applicability of minor and trace...... element patterns in cod otoliths for age determination. By first identifying elements of interest in a stock without ageing problems, western Baltic cod, we then tested their applicability on another stock without ageing problems, North Sea cod, and finally applied this knowledge to estimate age of......, the same patterns in Cu, Zn, Rb, Mg, and Mn signals occurred. All eastern Baltic cod with low visual contrast between growth zones exhibited clearly defined synchronous cycles in Cu, Zn, Rb and Pb. Using a combined finite differencing method and structural break models approach, the statistical...

  4. Sagittal otolith size and shape variability to identify geographical intraspecific differences in three species of the genus Merluccius

    OpenAIRE

    Torres, G. J.; Lombarte, Antoni; Morales-nin, Beatriz

    2000-01-01

    A study was carried out on the morphology (size and shape) of the saccular otolith (sagitta) by means of image analysis on three species of the genus Merluccius (M. gayi, M. hubbsi and M. merluccius). By digitization of the sagittae, morphometry and outline (Fourier harmonic) as form descriptor measurements were obtained, that were subsequently analysed by means of multivariant methods, allowing the intraspecific variability to be quantified. The differences in the intraspecific sagittal otol...

  5. Of travertine and time: otolith chemistry and microstructure detect provenance and demography of endangered humpback chub in Grand Canyon, USA

    Science.gov (United States)

    Limburg, Karin E.; Hayden, Todd A.; Pine, William E.; Yard, Michael D.; Kozdon, Reinhard; Valley, John W.

    2013-01-01

    We developed a geochemical atlas of the Colorado River in Grand Canyon and in its tributary, the Little Colorado River, and used it to identify provenance and habitat use by Federally Endangered humpback chub, Gila cypha. Carbon stable isotope ratios (δ13C) discriminate best between the two rivers, but fine scale analysis in otoliths requires rare, expensive instrumentation. We therefore correlated other tracers (SrSr, Ba, and Se in ratio to Ca) to δ13C that are easier to quantify in otoliths with other microchemical techniques. Although the Little Colorado River’s water chemistry varies with major storm events, at base flow or near base flow (conditions occurring 84% of the time in our study) its chemistry differs sufficiently from the mainstem to discriminate one from the other. Additionally, when fish egress from the natal Little Colorado River to the mainstem, they encounter cold water which causes the otolith daily growth increments to decrease in size markedly. Combining otolith growth increment analysis and microchemistry permitted estimation of size and age at first egress; size at first birthday was also estimated. Emigrants < 1 year old averaged 51.2 ± 4.4 (SE) days and 35.5 ± 3.6 mm at egress; older fish that had recruited to the population averaged 100 ± 7.8 days old and 51.0 ± 2.2 mm at egress, suggesting that larger, older emigrants recruit better. Back-calculated size at age 1 was unimodal and large (78.2 ± 3.3 mm) in Little Colorado caught fish but was bimodally distributed in Colorado mainstem caught fish (49.9 ± 3.6 and 79 ± 4.9 mm) suggesting that humpback chub can also rear in the mainstem. The study demonstrates the coupled usage of the two rivers by this fish and highlights the need to consider both rivers when making management decisions for humpback chub recovery.

  6. Of travertine and time: otolith chemistry and microstructure detect provenance and demography of endangered humpback chub in Grand Canyon, USA.

    Directory of Open Access Journals (Sweden)

    Karin E Limburg

    Full Text Available We developed a geochemical atlas of the Colorado River in Grand Canyon and in its tributary, the Little Colorado River, and used it to identify provenance and habitat use by Federally Endangered humpback chub, Gila cypha. Carbon stable isotope ratios (δ(13C discriminate best between the two rivers, but fine scale analysis in otoliths requires rare, expensive instrumentation. We therefore correlated other tracers (SrSr, Ba, and Se in ratio to Ca to δ(13C that are easier to quantify in otoliths with other microchemical techniques. Although the Little Colorado River's water chemistry varies with major storm events, at base flow or near base flow (conditions occurring 84% of the time in our study its chemistry differs sufficiently from the mainstem to discriminate one from the other. Additionally, when fish egress from the natal Little Colorado River to the mainstem, they encounter cold water which causes the otolith daily growth increments to decrease in size markedly. Combining otolith growth increment analysis and microchemistry permitted estimation of size and age at first egress; size at first birthday was also estimated. Emigrants < 1 year old averaged 51.2 ± 4.4 (SE days and 35.5 ± 3.6 mm at egress; older fish that had recruited to the population averaged 100 ± 7.8 days old and 51.0 ± 2.2 mm at egress, suggesting that larger, older emigrants recruit better. Back-calculated size at age 1 was unimodal and large (78.2 ± 3.3 mm in Little Colorado caught fish but was bimodally distributed in Colorado mainstem caught fish (49.9 ± 3.6 and 79 ± 4.9 mm suggesting that humpback chub can also rear in the mainstem. The study demonstrates the coupled usage of the two rivers by this fish and highlights the need to consider both rivers when making management decisions for humpback chub recovery.

  7. Of travertine and time: otolith chemistry and microstructure detect provenance and demography of endangered humpback chub in Grand Canyon, USA.

    Science.gov (United States)

    Limburg, Karin E; Hayden, Todd A; Pine, William E; Yard, Michael D; Kozdon, Reinhard; Valley, John W

    2013-01-01

    We developed a geochemical atlas of the Colorado River in Grand Canyon and in its tributary, the Little Colorado River, and used it to identify provenance and habitat use by Federally Endangered humpback chub, Gila cypha. Carbon stable isotope ratios (δ(13)C) discriminate best between the two rivers, but fine scale analysis in otoliths requires rare, expensive instrumentation. We therefore correlated other tracers (SrSr, Ba, and Se in ratio to Ca) to δ(13)C that are easier to quantify in otoliths with other microchemical techniques. Although the Little Colorado River's water chemistry varies with major storm events, at base flow or near base flow (conditions occurring 84% of the time in our study) its chemistry differs sufficiently from the mainstem to discriminate one from the other. Additionally, when fish egress from the natal Little Colorado River to the mainstem, they encounter cold water which causes the otolith daily growth increments to decrease in size markedly. Combining otolith growth increment analysis and microchemistry permitted estimation of size and age at first egress; size at first birthday was also estimated. Emigrants < 1 year old averaged 51.2 ± 4.4 (SE) days and 35.5 ± 3.6 mm at egress; older fish that had recruited to the population averaged 100 ± 7.8 days old and 51.0 ± 2.2 mm at egress, suggesting that larger, older emigrants recruit better. Back-calculated size at age 1 was unimodal and large (78.2 ± 3.3 mm) in Little Colorado caught fish but was bimodally distributed in Colorado mainstem caught fish (49.9 ± 3.6 and 79 ± 4.9 mm) suggesting that humpback chub can also rear in the mainstem. The study demonstrates the coupled usage of the two rivers by this fish and highlights the need to consider both rivers when making management decisions for humpback chub recovery. PMID:24358346

  8. Elemental patterns in red hind (Epinephelus guttatus) otoliths from Bermuda and Puerto Rico reflect growth rate, not temperature

    OpenAIRE

    Sadovy, Y; Severin, KP

    1994-01-01

    Sodium, sulfur, calcium, and strontium concentrations were measured (with an electron microprobe across sectioned wild red hind (Epinephelus guttatus) otoliths from Puerto Rico and Bermuda. A single inverse relationship between strontium/calcium (Sr/Ca) ratios and log body growth rate describes the data from both localities. Patterns in Sr/Ca ratios have been used to infer temperature histories of individual fish; our data indicate that there is not a single Sr/Ca-temperature relationship cap...

  9. Otolith chemistry of fishes from Kosi Bay, South Africa: A preliminary multiple analytical methods approach to reconstruct fish migrations

    Science.gov (United States)

    Holbach, Andreas; Cowley, Paul D.; Kramar, Utz; Neumann, Thomas

    2012-08-01

    Over exploitation of fish stocks in coastal areas is a subject of global concern. Increasing numbers of traditional fish traps, recreational fishing effort and unknown extents of illegal gillnetting are blamed for the declining abundance of estuarine-dependent fish species in the Kosi Bay estuarine lake system in KwaZulu-Natal, South Africa. Otoliths from four important fishery species (Lutjanus argentimaculatus, Pomadasys commersonnii, Acanthopagrus vagus, and Rhabdosargus sarba) and water samples collected from throughout the Kosi Bay system were analyzed for trace element constituents and δ18O values, in an attempt to reconstruct fish movements. The applied microscopic X-ray fluorescence analysis proved valuable in detecting μm-scale spatially resolved Sr/Ca ratio distributions across otolith thin sections. Sr/Ca ratios and δ18O in otoliths correlated well with ambient water conditions and, thus, enabled us to reconstruct migratory histories of individual fish in the estuarine lake system. The findings are representative of the known biology of these species, although exact spatial and temporal ranges of migrations remain unclear. Interestingly, samples of two species (L. argentimaculatus and R. sarba) did not show any clue of migrations back to sea, which would be necessary for successful spawning. Further laboratory and field investigations with larger sample sizes are necessary to detect fishery impacts on migratory behavior at a population level.

  10. Estimating contemporary early life-history dispersal in an estuarine fish: integrating molecular and otolith elemental approaches.

    Science.gov (United States)

    Bradbury, I R; Campana, S E; Bentzen, P

    2008-03-01

    Dispersal during the early life history of the anadromous rainbow smelt, Osmerus mordax, was examined using assignment testing and mixture analysis of multilocus genotypes and otolith elemental composition. Six spawning areas and associated estuarine nurseries were sampled throughout southeastern Newfoundland. Samples of adults and juveniles isolated by > 25 km displayed moderate genetic differentiation (F(ST) ~ 0.05), whereas nearby (nursery samples displayed low differentiation (F(ST) 80% self-assignment) with nearby runs self-assigning at rates between 50 % and 70%. Assignment and mixture analysis of juveniles using adult baselines indicated high local recruitment at several locations (70-90%). Nearby (estuaries at the head of St Mary's Bay showed mixtures of individuals (i.e. 20-40% assignment to adjacent spawning location). Laser ablation inductively coupled mass spectrometry transects across otoliths of spawning adults of unknown dispersal history were used to estimate dispersal among estuaries across the first year of life. Single-element trends and multivariate discriminant function analysis (Sr:Ca and Ba:Ca) classified the majority of samples as estuarine suggesting limited movement between estuaries (juveniles evident in the genetic data at nearby sites and a lack of evidence of straying in the otolith data support a hypothesis of selective mortality of immigrants. If indeed selective mortality of immigrants reduces the survivorship of dispersers, estimates of dispersal in marine environments that neglect survival may significantly overestimate gene flow.

  11. Electronmicroscopic Investigations on the Role of Vesicle-like Bodies in Inner Ear Maculae for Fish Otolith Growth

    Science.gov (United States)

    Ibsch, M.; Vöhringer, P.; Anken, R. H.; Rahmann, H.

    The presence, morphology and possible origin of vesicle-like bodies (VBs) within the inner ear otolithic membrane of developmental stages of cichlid fish Oreochromis mossambicus and adult swordtail fish Xiphophorus helleri was analysed by means of transmission and scanning electron microscopy (TEM and SEM, respectively) employing various fixation procedures. The VBs are believed to be involved in the formation of the otolith (or statolith in birds and mammals) regarding the supply of the otolith's organic material. Increasing the osmolarity of the fixation medium decreased the number of VBs seen. Decalcification ended up in a complete disappearance of the VBs. Whilst a fixation with glutaraldehyde followed by OS04 fixation yielded numerous VBs, only few of them were observed when the tissue was fixed with glutaraldehyde and OSO4 simultaneously. Therefore, the results strongly suggest that the VBs are fixative (i.e., glutaraldehyde) induced artifacts, so-called blisters. With this, the supply of an oto- or statolith's organic material remains obscure. Possibly, it is provided by secretion from the supporting cells as has been hypothesized earlier

  12. Role of irregular otolith afferents in the steady-state nystagmus during off-vertical axis rotation

    Science.gov (United States)

    Angelaki, D. E.; Perachio, A. A.; Mustari, M. J.; Strunk, C. L.

    1992-01-01

    1. During constant velocity off-vertical axis rotations (OVAR) in the dark a compensatory ocular nystagmus is present throughout rotation despite the lack of a maintained signal from the semicircular canals. Lesion experiments and canal plugging have attributed the steady-state ocular nystagmus during OVAR to inputs from the otolith organs and have demonstrated that it depends on an intact velocity storage mechanism. 2. To test whether irregularly discharging otolith afferents play a crucial role in the generation of the steady-state eye nystagmus during OVAR, we have used anodal (inhibitory) currents bilaterally to selectively and reversibly block irregular vestibular afferent discharge. During delivery of DC anodal currents (100 microA) bilaterally to both ears, the slow phase eye velocity of the steady-state nystagmus during OVAR was reduced or completely abolished. The disruption of the steady-state nystagmus was transient and lasted only during the period of galvanic stimulation. 3. To distinguish a possible effect of ablation of the background discharge rates of irregular vestibular afferents on the velocity storage mechanism from specific contributions of the dynamic responses from irregular otolith afferents to the circuit responsible for the generation of the steady-state nystagmus, bilateral DC anodal galvanic stimulation was applied during optokinetic nystagmus (OKN) and optokinetic afternystagmus (OKAN). No change in OKN and OKAN was observed.(ABSTRACT TRUNCATED AT 250 WORDS).

  13. Age Determination of Microlepidotus brevipinnis (Steindachner, 1869 (Pisces: Haemulidae in the Coast of Jalisco, Mexico, by Reading Otoliths and Scales

    Directory of Open Access Journals (Sweden)

    E.G. Cabral-Solis

    2010-01-01

    Full Text Available This study deals with age determination of the brassy grunt Microlepidotus brevipinnis by reading otoliths (sagittae and scales which allowed the identification of 13 age groups. Growth of otoliths and scales is proportional to the growth of the fish. The time of formation of fast and slow growth bands in sagittae, as well as the time of ring formation in the scales is one year. The highest growth in length of this species takes place during the first year of life, in which the organism reaches 125.0 mm, this reduces natural mortality of the individuals by decreasing depredation. Growth in weight of this species is isometric. Sexual differentiation of the organisms is apparent after the age of two years and there were differences in the average length for each age in scales and otoliths for males and females. The age of other members of the Haemulidae family were compared with those obtained in the present study and M. brevipinnis reaches its oldest age in 13 years. It occupies a middle point (442.4 mm in relation to the total lengths of other haemulids in the Mexican Pacific coast.

  14. Life history inhomogeneity in Baltic Sea whitefish populations revealed by otolith strontium signatures – identification of stocked fish

    Directory of Open Access Journals (Sweden)

    Henry Hägerstrand

    2015-11-01

    The strontium concentrations in the otolith cores of whitefish from River Tornionjoki were higher than that of the four otoliths with low core strontium from fishes caught at sea (Table 1. Supposing that this latter group represent stocked fish raised in freshwater ponds, the vast majority of River Tornionjoki whitefish is naturally reproduced fish. This is plausible because in River Tornionjoki, the major whitefish spawning river in Finland, no larger stocking have been made since 1990s (Jokikokko and Huhmarniemi 2014. In conclusion, the concentration of otolith core strontium differs in whitefish hatched in fresh-water and in whitefish hatched in river water or in brackish Baltic Sea water. This difference can be used to reveal stocked whitefish. Barium concentration may be an even better indicator in this respect than strontium, as previous results indicate (Hägerstrand et al., 2015. Stocked river spawning whitefish appear in large amount at the southern feeding grounds around the Åland Islands, as already indicated by e.g. Leskelä et al. (2009.

  15. Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, A H; Kerr, L A; Cailliet, G M; Brown, T A; Lundstrom, C C; Stanley, R D

    2007-11-04

    Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

  16. Growth conditions of 0-group plaice Pleuronectes platessa in the western Wadden Sea as revealed by otolith microstructure analysis

    Science.gov (United States)

    Cardoso, Joana F. M. F.; Freitas, Vânia; de Paoli, Hélène; Witte, Johannes IJ.; van der Veer, Henk W.

    2016-05-01

    Growth studies based on population-based growth estimates are limited by the fact that they do not take into account differences in age/size structure within the population. To overcome these problems, otolith microstructure analysis is often used to estimate individual growth. Here, we analyse growth of 0-group plaice in the western Wadden Sea in two years: a year preceded by a mild winter (1995) and a year preceded by a severe winter (1996). Growth was analysed by combining information on individual growth based on otolith analysis with predictions of maximum growth (= under optimal food conditions) based on a Dynamic Energy Budget model. Otolith analysis revealed that settlement occurred earlier in 1995 than in 1996. In both years, one main cohort was found, followed by a group of late settlers. No differences in mean length-at-age were found between these groups. DEB modelling suggested that growth was not maximal during the whole growing season: realized growth (the fraction of maximum growth realized by 0-group plaice) declined in the summer, although this decline was relatively small. In addition, late settling individuals exhibited lower realized growth than individuals from the main cohort. This study confirms that growth conditions for 0-group plaice are not optimal and that a growth reduction occurs in summer, as suggested in previous studies.

  17. Oldest isotopically characterized fish otoliths provide insight to Jurassic continental climate of Europe

    Science.gov (United States)

    Patterson, William P.

    1999-03-01

    Large, shallow, epeiric seas and adjacent lagoons such as those described herein likely played a significant role in moderating Jurassic coastal and continental climate. Jurassic (Bathonian) ocean surface temperatures in Scotland have been calculated from δ18O(CaCO3) values of a suite of the oldest well-preserved fish otoliths analyzed to date. Otolith δ18O values range from -4.7‰ to -1.9‰ (Vienna Peedee belemnite, VPDB), while δ13C(CaCO3) values vary from -5.4‰ to +1.5‰ (VPDB), representing the oldest stable isotopic record of paleodiet, paleoecology, and fish migration to date. Using a global ocean δ18O(H2O) value of -1.0‰ (Vienna standard mean ocean water, VSMOW) for an ice-free Jurassic, fish species that migrated from estuarine to open marine water record time-averaged temperatures of 23 °C. Estuarine fish, assuming a similar temperature, record variation in δ18O(H2O) values from -3.7‰ to -2.0‰ (VSMOW). That significant mixing of fresh water and seawater occurred in the Jurassic in Scotland is in general agreement with data presented by others (molluscan fauna, lithostratigraphy, paleogeography, and paleocirculation models). The δ18O values and temperatures derived in this study correspond to the meteorologic and hydrologic parameters of a mid-latitude maritime climate with low seasonality, a mean temperature of 23 °C, and abundant precipitation and humidity. The δ18O(H2O) values calculated from estuarine fish indicate that rainfall must have a δ18O(H2O) value lower than -3.7‰ (VSMOW). Values of δ18O and δ13C suggest an environment hydrologically similar to that observed in the Everglades of south Florida or the estuaries of south Texas, both notable fish nurseries today. However, sea-surface temperatures were lower than those of modern Florida or Texas as evidenced by reduced evaporative enrichment of δ18O(H2O) values.

  18. Age estimation of juvenile European hake Merluccius merluccius based on otolith microstructure analysis: a slow or fast growth pattern?

    Science.gov (United States)

    Pattoura, P; Lefkaditou, E; Megalofonou, P

    2015-03-01

    The main goal of this study was to examine otolith microstructure and to estimate the age and growth of European hake Merluccius merluccius from the eastern Mediterranean Sea. One hundred and twenty-nine specimens ranging from 102 to 438 mm in total length (LT ) were used. Age estimations were based on the study of the otolith microstructure, which was revealed after grinding both frontal sides of otoliths. The enumerations of the daily growth increments (DGI) as well as their width (WDGI ) measurements were made on calibrated digital images. The number of DGI in otoliths ranged between 163 and 717. Four phases in the WDGI evolution were distinguished: (1) larval-juvenile pelagic phase, with an increasing trend in WDGI up to the 60th DGI, (2) settlement phase, with a short-term deceleration in WDGI between the 61st and 150th DGI, (3) juvenile demersal phase, characterized by a stabilization of WDGI from 151st to 400th DGI and (4) adult phase, with a decreasing trend in WDGI after the 400th DGI. Age, sex and month of formation were found to affect the WDGI in all phases, with the exception of age at the juvenile demersal phase. The power curve with intercept model described best the relationship of M. merluccius LT with age (TDGI ), according to Akaike criteria, revealing differences in growth between females [LT = 65 · 36(TDGI )(0 · 40) - 388 · 55] and males [LT = 69 · 32(TDGI )(0 · 37) - 352 · 88] for the sizes examined. The mean daily growth rates were 0·61 mm day(-1) for females and 0·52 mm day(-1) for males, resulting in an LT of 283 and 265 mm at the end of their first year of life. In comparison with previous studies on the Mediterranean Sea, the results of this study showed a greater growth rate, similar to results from tagging experiments and otolith microstructure analyses for M. merluccius in other geographic areas. PMID:25545134

  19. Convergence of limb, visceral, and vertical semicircular canal or otolith inputs onto vestibular nucleus neurons

    Science.gov (United States)

    Jian, B. J.; Shintani, T.; Emanuel, B. A.; Yates, B. J.

    2002-01-01

    The major goal of this study was to determine the patterns of convergence of non-labyrinthine inputs from the limbs and viscera onto vestibular nucleus neurons receiving signals from vertical semicircular canals or otolith organs. A secondary aim was to ascertain whether the effects of non-labyrinthine inputs on the activity of vestibular nucleus neurons is affected by bilateral peripheral vestibular lesions. The majority (72%) of vestibular nucleus neurons in labyrinth-intact animals whose firing was modulated by vertical rotations responded to electrical stimulation of limb and/or visceral nerves. The activity of even more vestibular nucleus neurons (93%) was affected by limb or visceral nerve stimulation in chronically labyrinthectomized preparations. Some neurons received non-labyrinthine inputs from a variety of peripheral sources, including antagonist muscles acting at the same joint, whereas others received inputs from more limited sources. There was no apparent relationship between the spatial and dynamic properties of a neuron's responses to tilts in vertical planes and the non-labyrinthine inputs that it received. These data suggest that non-labyrinthine inputs elicited during movement will modulate the processing of information by the central vestibular system, and may contribute to the recovery of spontaneous activity of vestibular nucleus neurons following peripheral vestibular lesions. Furthermore, some vestibular nucleus neurons with non-labyrinthine inputs may be activated only during particular behaviors that elicit a specific combination of limb and visceral inputs.

  20. On Strongly Coupled Linear Elliptic Systems with Application to Otolith Membrane Distortion

    Directory of Open Access Journals (Sweden)

    I. K. Youssef

    2008-01-01

    Full Text Available Problem Statement: In this research, the author discussed the problems associated with the approximation of the mixed derivative terms appearing in strongly coupled linear elliptic systems by the finite difference method over irregular domains. To avoid the appearance of mixed derivative terms the author introduced a reformulation for the system through introducing a new dependent variable which adds one supplementary (simple differential equation to the system but does not change its elliptic character. Approach: The basic idea in the reformulation is the direct generation of the Laplacian operator which has an efficient finite difference treatment. Results: Two finite difference formulae with symmetric appearance approximating the first order derivatives on curved boundaries up to O(h2 are established, that can be considered as a generalization to the well known central formula. Applications to the otolith membrane model have proved the reliability and efficiency of the present treatment in comparison with other methods. Conclusions/Recommendations: Although, this treatment has increased the number of algebraic equations approximating the system linearly 3n instead of 2n, the overall accuracy is increased quadratically. The band width of matrix of coefficients of the algebraic system is decreased and there is no need to interpolate along the diagonals due to the absence of mixed derivatives. The treatment is promising and other extensions are mentioned.

  1. Preliminary results of Sr:Ca ratios of Coilia nasus in otoliths by micro-PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, L. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China); Guo, H. [Institute of Life Science, Shanghai Fisheries University, Shanghai 200090 (China); Shen, H. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China)]. E-mail: haoshen@fudan.edu.cn; Li, X. [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China); Tang, W. [Institute of Life Science, Shanghai Fisheries University, Shanghai 200090 (China); Liu, J. [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China); Jin, J. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China); Mi, Y. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China)

    2007-07-15

    Coilia nasus, distributed in Changjiang River as well as northwest Pacific, has a high economic value owing to its delicacy and nutritional value. Recently, the fishing yields in Changjiang River have decreased dramatically due to excessive fishing and changes in the aquatic ecology. In order to prevent excessive fishing effectively, the life history pattern of C. nasus should be known in detail. Ootoliths contain much information about a fish's life history, because elemental concentrations remain unaltered after deposition, and can be analysed. C. nasus collected from Jing Jiang (lower reaches of the Changjiang River) and Jiu Duan Sha (the estuary of the Changjiang River) were studied by measuring Sr:Ca ratios in their otoliths using micro-PIXE. On average, the Sr:Ca ratios of estuarine C. nasus were found to be higher. The Sr:Ca ratios were higher in the core regions and lower in the outermost marginal regions, and shows fluctuations in certain regions. Possible corresponding life history patterns are discussed.

  2. Distinguishing wild vs. stocked lake trout (Salvelinus namaycush) in Lake Ontario: Evidence from carbon and oxygen stable isotope values of otoliths

    Science.gov (United States)

    Schaner, T.; Patterson, W.P.; Lantry, B.F.; O'Gorman, R.

    2007-01-01

    We investigated the potential for using carbon and oxygen isotope values of otolith carbonate as a method to distinguish naturally produced (wild) lake trout (Salvelinus namaycush) from hatchery-reared lake trout in Lake Ontario. We determined δ 13C(CaCO3) and δ 18O(CaCO3) values of otoliths from juvenile fish taken from two hatcheries, and of otoliths from wild yearlings. Clear differences in isotope values were observed between the three groups. Subsequently we examined otoliths from large marked and unmarked fish captured in the lake, determining isotope values for regions of the otolith corresponding to the first year of life. Marked (i.e., stocked) fish showed isotope ratios similar to one of the hatchery groups, whereas unmarked fish, (wild fish or stocked fish that lost the mark) showed isotope ratios similar either to one of the hatchery groups or to the wild group. We interpret these data to suggest that carbon and oxygen isotope values can be used to determine the origin of lake trout in Lake Ontario, if a catalogue of characteristic isotope values from all candidate years and hatcheries is compiled.

  3. Species and life-history affects the utility of otolith chemical composition to determine natal stream-of-origin in Pacific salmon

    Science.gov (United States)

    Zimmerman, Christian E.; Swanson, Heidi K.; Volk, Eric C.; Kent, Adam J.R.

    2013-01-01

    To test the utility of otolith chemical composition as a tool for determining the natal stream of origin for salmon, we examined water chemistry and otoliths of juvenile and adult Chum Salmon Oncorhynchus keta and Coho Salmon O. kisutch from three watersheds (five rivers) in the Norton Sound region of Alaska. The two species are characterized by different life histories: Coho Salmon rear in freshwater for up to 3 years, whereas Chum Salmon emigrate from freshwater shortly after emergence. We used laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) to quantify element: Ca ratios for Mg, Mn, Zn, Sr, and Ba, and we used multicollector LA-ICP-MS to determine 87Sr:86Sr ratios in otolith regions corresponding to the period of freshwater residence. Significant differences existed in both water and otolith elemental composition, suggesting that otolith composition could be used to discriminate the natal origin of Coho Salmon and Chum Salmon but only when 87Sr:86Sr ratios were included in the discriminant function analyses. The best discriminant model included 87Sr:86Sr ratios, and without 87Sr:86Sr ratios it was difficult to discriminate among watersheds and rivers. Classification accuracy was 80% for Coho Salmon and 68% for Chum Salmon, indicating that this method does not provide sufficient sensitivity to estimate straying rates of Pacific salmon at the scale we studied.

  4. Atlas of marine bony fish otoliths (Sagittae of Southeastern - Southern Brazil Part I: Gadiformes (Macrouridae, Moridae, Bregmacerotidae, Phycidae and Merlucciidae; Part II: Perciformes (Carangidae, Sciaenidae, Scombridae and Serranidae

    Directory of Open Access Journals (Sweden)

    Carmen Lucia Del Bianco Rossi-Wongtschowski

    2014-01-01

    Full Text Available The drawings, detailed pictures, precise descriptions and measurements that characterize otoliths must be made available for studies in various areas, including taxonomy, phylogeny, ecology, fisheries, paleontology, diversity, predator-prey relationships and modeling. The Collection of Teleostei Fish Otoliths of Southeastern-Southern Brazil (COSS-Brasil of IOUSP contains 45,000 pairs of otoliths from 210 species. This publication is the first in a series that will constitute an atlas of Teleostei otoliths for southeastern-southern Brazil and presents the results of the morphologic and morphometric analyses of 11 Gadiformes and 36 Perciformes species by means of the most commonly used features, measurements and indices. Three otoliths of each species were illustrated and photographed whenever possible. The frequency of occurrence was calculated for each characteristic by total length classes (TL, and the ontogenetic differences were analyzed (multiple χ2 test; significance 0.05. Morphometric analyses were conducted for each characteristic per total length (TL class and for the whole sample, and the ontogenetic differences were analyzed.

  5. An otolith microchemistry study of possible relationships between the origins of leptocephali of European eels in the Sargasso Sea and the continental destinations and relative migration success of glass eels

    DEFF Research Database (Denmark)

    Martin, J.; Daverat, F.; Pécheyran, C.;

    2010-01-01

    Little is known about the extent to which Atlantic eels coming from different European rivers converge on the same spawning site. Our aim was to evaluate the spatial homogeneity of eel spawning area(s) with an otolith microchemistry approach. This work compared the elemental signatures of otolith...

  6. The mangrove nursery paradigm revisited: otolith stable isotopes support nursery-to-reef movements by Indo-Pacific fishes.

    Directory of Open Access Journals (Sweden)

    Ismael A Kimirei

    Full Text Available Mangroves and seagrass beds have long been perceived as important nurseries for many fish species. While there is growing evidence from the Western Atlantic that mangrove habitats are intricately connected to coral reefs through ontogenetic fish migrations, there is an ongoing debate of the value of these coastal ecosystems in the Indo-Pacific. The present study used natural tags, viz. otolith stable carbon and oxygen isotopes, to investigate for the first time the degree to which multiple tropical juvenile habitats subsidize coral reef fish populations in the Indo Pacific (Tanzania. Otoliths of three reef fish species (Lethrinus harak, L. lentjan and Lutjanus fulviflamma were collected in mangrove, seagrass and coral reef habitats and analyzed for stable isotope ratios in the juvenile and adult otolith zones. δ(13C signatures were significantly depleted in the juvenile compared to the adult zones, indicative of different habitat use through ontogeny. Maximum likelihood analysis identified that 82% of adult reef L. harak had resided in either mangrove (29% or seagrass (53% or reef (18% habitats as juveniles. Of adult L. fulviflamma caught from offshore reefs, 99% had passed through mangroves habitats as juveniles. In contrast, L. lentjan adults originated predominantly from coral reefs (65-72% as opposed to inshore vegetated habitats (28-35%. This study presents conclusive evidence for a nursery role of Indo-Pacific mangrove habitats for reef fish populations. It shows that intertidal habitats that are only temporarily available can form an important juvenile habitat for some species, and that reef fish populations are often replenished by multiple coastal habitats. Maintaining connectivity between inshore vegetated habitats and coral reefs, and conserving habitat mosaics rather than single nursery habitats, is a major priority for the sustainability of various Indo Pacific fish populations.

  7. Radiocarbon in otoliths of yelloweye rockfish (Sebastes ruberrimus): a reference time series for the coastal waters of southeast Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Kerr-Ferrey, L A; Andrews, A H; Frantz, B R; Coale, K H; Brown, T A; Cailliet, G M

    2003-10-14

    Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the environment that has provided a useful tracer and chronological marker in oceanic systems and organisms. The bomb-generated {sup 14}C signal retained in fish otoliths can be used as a permanent, time-specific recorder of the 14C present in ambient seawater, making it a useful tool in age validation of fishes. The goal of this study was to determine {sup 14}C levels in otoliths of the age-validated yelloweye rockfish (Sebastes ruberrimus) to establish a reference time series for the coastal waters of southeast Alaska. Radiocarbon values from the first year's growth of 43 yelloweye rockfish otoliths were plotted against estimated birth year to produce a 14C time series for these waters spanning 1940 to 1990. The time series shows the initial rise of bomb 14C occurred in 1958 in coastal southeast Alaskan waters and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values (60-70%) between 1966 and 1971, with a subsequent declining trend through the end of the record in 1990 (-3.2%). In addition, the radiocarbon data, independent of the radiometric study, confirms the longevity of the yelloweye rockfish up to a minimum of 44 years and strongly supports higher age estimates. The yelloweye rockfish record provides a {sup 14}C chronology that will be useful for the interpretation of {sup 14}C accreted in biological samples from these waters and in future rockfish age validation studies.

  8. Water temperature and fish growth: otoliths predict growth patterns of a marine fish in a changing climate.

    Science.gov (United States)

    Rountrey, Adam N; Coulson, Peter G; Meeuwig, Jessica J; Meekan, Mark

    2014-08-01

    Ecological modeling shows that even small, gradual changes in body size in a fish population can have large effects on natural mortality, biomass, and catch. However, efforts to model the impact of climate change on fish growth have been hampered by a lack of long-term (multidecadal) data needed to understand the effects of temperature on growth rates in natural environments. We used a combination of dendrochronology techniques and additive mixed-effects modeling to examine the sensitivity of growth in a long-lived (up to 70 years), endemic marine fish, the western blue groper (Achoerodus gouldii), to changes in water temperature. A multi-decadal biochronology (1952-2003) of growth was constructed from the otoliths of 56 fish collected off the southwestern coast of Western Australia, and we tested for correlations between the mean index chronology and a range of potential environmental drivers. The chronology was significantly correlated with sea surface temperature in the region, but common variance among individuals was low. This suggests that this species has been relatively insensitive to past variations in climate. Growth increment and age data were also used in an additive mixed model to predict otolith growth and body size later this century. Although growth was relatively insensitive to changes in temperature, the model results suggested that a fish aged 20 in 2099 would have an otolith about 10% larger and a body size about 5% larger than a fish aged 20 in 1977. Our study shows that species or populations regarded as relatively insensitive to climate change could still undergo significant changes in growth rate and body size that are likely to have important effects on the productivity and yield of fisheries.

  9. Regional and seasonal differences in growth of larval North Sea herring (clupea harengus L.) estimated by otolith microstructure analysis

    DEFF Research Database (Denmark)

    Munk, Peter; Heath, Mike; Skaarup, Bo

    1991-01-01

    The ecology processes of the larval life of autumn-spawned North Sea herring have been studied in a multidisciplinary and internationally coordinated research programme (ACE). The programme focused on larval advection and the importance of the autumn/winter circulation in determining larval...... between larval length and otolith ring structure within defined geographical regions and restricted periods of time. The analysis indicates a 45% decrease in growth rates through the autumn/winter period along with a substantial difference between southern and northern areas, the growth rates in the south...

  10. Life history traits of the fish community in Lake Annecy: evidence from the stable isotope composition of otoliths

    Directory of Open Access Journals (Sweden)

    Gerdeaux D.

    2015-01-01

    Full Text Available Stable isotope analysis (SIA of fish otoliths shows great potential for exploring the ecology of fish, but this method has not been applied to the study of lacustrine fish communities. Both sequential and whole-otolith SIAs were performed on six fish species of Lake Annecy and their results compared to muscle SIA. The first purpose of these investigations was to test the use of δ18Ooto values for reconstructing fish thermal history and delimiting spatial distribution in a stratified lake. Comparison of species-specific fractionation equations and the general equation developed for freshwater fishes showed that the general one was the best suited for thermal estimation of Lake Annecy fishes and suggested that inter-specific differences or specific “vital effects” are not the only reason for apparent difference in fractionation. Thermal estimations based on SIA were consistent with descriptions of thermal habitats in the literature, except in the case of roach (Rutilus rutilus. Based on the current results, roach appears to live in a colder habitat than do perch (Perca fluviatilis. The high water transparency and thermal stratification of Lake Annecy could explain this distribution. Moreover, perch juveniles were found to live in two different thermal niches. This finding highlights the great plasticity of the species. Second, the potential use of δ13Coto values to reconstruct variation in diet and metabolism was assessed. The proportion of metabolic carbon (M contributing to otolith carbon varies markedly among species. Comparison with δ13Cmuscle values shows no direct relationship between δ13Coto and diet at either the intra-individual or the inter-specific level. A strong linear relationship between either M or the isotopic offset between otolith and muscle (Δδ13Coto - muscle and δ18Ooto values was found; this relationship reveals the dependence of M on the ambient temperature at which the species occurs. This relationship might be

  11. Evaluation of Response Patterns in Somatic and Otolith Features of Laboratory- Reared and Wild Clarias gariepinus Exposed to Industrial Effluent

    OpenAIRE

    Adeogun, Aina O.; Taofeek A. Babatunde; Azubuike V. Chukwuka

    2013-01-01

    This study was aimed at comparing the responses of somatic and otolith features in Clarias gariepinus under chronic exposure conditions to industrial effluents in the laboratory for 60 days and in the wild for 6 months. Fish were collected upstream and downstream bi-monthly from a river receiving composite mixtures of industrial effluent while laboratory-rearedC. gariepinus were exposed to the same effluent mixtures in 60 days static renewal/bioassay using concentrations of 6.11, 3.05 and 2.2...

  12. The Otolith Group’s “Monuments to Dead Television.” Independent Cinema and the Migrant Experience in Europe between Television and the Museum

    Directory of Open Access Journals (Sweden)

    Beatrice Ferrara

    2014-04-01

    Full Text Available “Monument to dead television” is the expression the British collective The Otolith Group uses to define its activity of recuperating long-lost quality films, and re-screening them in contemporary art museums and gallery spaces. What these films share is a cinematic vocation and a complex approach to the question of memory and migration in Europe, and to the role of images as testimonies or documents. This essay explores The Otolith Group’s interest in such forgotten archives of modern television in order to unearth their significance for contemporary museums today.

  13. Head movements suggest canal and otolith projections are activated during galvanic vestibular stimulation.

    Science.gov (United States)

    Kim, J

    2013-12-01

    Three-dimensional changes in the angular orientation of the head were monitored during galvanic vestibular stimulation (GVS) delivered through electrodes implanted bilaterally in the tensor tympani muscle of the guinea-pig middle ear. Bilateral GVS was delivered by passing current between both ears with the anode situated in one ear and the cathode in the other ear. Unilateral GVS was also delivered between one ear and an indifferent electrode on the skull. Constant-current stimulation caused the head to tilt predominantly within the roll and yaw planes toward an ear stimulated with anodal current and away from an ear stimulated with cathodal current. No significant head tilt in the pitch plane was observed with either bilateral or unilateral GVS. Bilateral GVS was found to induce significantly greater roll head tilt (RHT) and yaw head tilt (YHT) than the same intensity of unilateral anodal or cathodal GVS, but not the sum of responses induced by the two polarities of unilateral GVS. Significant asymmetries were observed in the responses of YHT and RHT for unilateral anodal and cathodal GVS; unilateral cathodal stimulation generated greater head deviation compared with the same intensity of unilateral anodal stimulation. These asymmetric responses are consistent with activation of irregularly discharging afferents, which have been shown previously to exhibit asymmetric responses for anodal and cathodal GVS (Kim and Curthoys, 2004). Together with the observations of previous guinea-pig studies, the results suggest that head movements induced by GVS may be mediated by irregularly discharging afferents innervating the otoliths, and possibly the horizontal semicircular canals. PMID:24021920

  14. Use of otoliths to estimate size at sexual maturity in fish

    Directory of Open Access Journals (Sweden)

    Carlos Sérgio Agostinho

    2000-01-01

    Full Text Available The viability of an alternative method for estimating the size at sexual maturity of females of Plagioscion squamosissimus (Perciformes, Sciaenidae was analyzed. This methodology was used to evaluate the size at sexual maturity in crabs, but has not yet been used for this purpose in fishes. Separation of young and adult fishes by this method is accomplished by iterative adjustment of straight-line segments to the data for length of the otolith and length of the fish. The agreement with the estimate previously obtained by another technique and the possibility of calculating the variance indicates that in some cases, the method analyzed can be used successfully to estimate size at sexual maturity in fish. However, additional studies are necessary to detect possible biases in the method.A viabilidade de uma metologia alternativa para a estimativa do tamanho de maturação sexual de fêmeas de Plagioscion squamosissimus (Perciformes, Sciaenidae foi analisada. Esta metodologia tem sido utilizada para avaliar o tamanho da maturação sexual em caranguejos mas ainda não havia sido utilizada em peixes com este objetivo. A separação dos peixes jovens e adultos por este método é feita pelo ajuste iterativo de segmentos de reta aos dados de comprimento do otólito e comprimento do peixe. A concordância com a estimativa obtida previamente utilizando outra técnica e a possibilidade do cálculo da variância indica que em alguns casos o método analisado pode ser utilizado com sucesso para estimar o tamanho de maturação sexual em peixes, mas outros estudos são necessários para se detectar possíveis bias do método.

  15. The impact of individual and combined abiotic factors on daily otolith growth in a coral reef fish.

    Science.gov (United States)

    Wenger, Amelia S; Whinney, James; Taylor, Brett; Kroon, Frederieke

    2016-01-01

    Coral reefs are increasingly subjected to both local and global stressors, however, there is limited information on how reef organisms respond to their combined effects under natural conditions. This field study examined the growth response of the damselfish Neopomacentrus bankieri to the individual and combined effects of multiple abiotic factors. Turbidity, temperature, tidal movement, and wave action were recorded every 10 minutes for four months, after which the daily otolith growth of N. bankieri was aligned with corresponding abiotic conditions. Temperature was the only significant driver of daily otolith increment width, with increasing temperatures resulting in decreasing width. Although tidal movement was not a significant driver of increment width by itself, the combined effect of tidal movement and temperature had a greater negative effect on growth than temperature alone. Our results indicate that temperature can drive changes in growth even at very fine scales, and demonstrate that the cumulative impact of abiotic factors can be substantially greater than individual effects. As abiotic factors continue to change in intensity and duration, the combined impacts of them will become increasingly important drivers of physiological and ecological change. PMID:27350589

  16. Evidence of estuarine nursery origin of five coastal fish species along the Portuguese coast through otolith elemental fingerprints

    Science.gov (United States)

    Vasconcelos, Rita P.; Reis-Santos, Patrick; Tanner, Susanne; Maia, Anabela; Latkoczy, Christopher; Günther, Detlef; Costa, Maria José; Cabral, Henrique

    2008-08-01

    Connectivity is a critical property of marine populations, particularly for species with segregated juvenile and adult habitats. Knowledge of this link is fundamental in understanding population structure and dynamics. Young adults of commercially important fish species Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax were sampled off the Portuguese coast in order to establish preliminary evidence of estuarine nursery origins through otolith elemental fingerprints. Concentrations of Li, Na, Mg, K, Mn, Cu, Zn, Sr, Ba and Pb in the otolith section corresponding to juvenile's nursery life period were determined through laser ablation inductively coupled plasma mass spectrometry. Element: Ca ratios in coastal fish differed significantly amongst collection areas, except for Platichthys flesus, and were compared with the elemental fingerprints previously defined for age 0 juveniles in the main estuarine nurseries of the Portuguese coast. Identification of nursery estuaries was achieved for four of the species. Assigned nursery origins varied amongst species and differences in the spatial scale of fish dispersal were also found. Diplodus vulgaris was not reliably assigned to any of the defined nurseries. Overall, results give evidence of the applicability of estuarine habitat tags in future assessments of estuarine nursery role. Research developments on the links between juvenile and adult habitats should contribute for the integrated management and conservation of nurseries and coastal stocks.

  17. Vestibulo-Ocular Responses to Vertical Translation using a Hand-Operated Chair as a Field Measure of Otolith Function

    Science.gov (United States)

    Wood, S. J.; Campbell, D. J.; Reschke, M. F.; Prather, L.; Clement, G.

    2016-01-01

    The translational Vestibulo-Ocular Reflex (tVOR) is an important otolith-mediated response to stabilize gaze during natural locomotion. One goal of this study was to develop a measure of the tVOR using a simple hand-operated chair that provided passive vertical motion. Binocular eye movements were recorded with a tight-fitting video mask in ten healthy subjects. Vertical motion was provided by a modified spring-powered chair (swopper.com) at approximately 2 Hz (+/- 2 cm displacement) to approximate the head motion during walking. Linear acceleration was measured with wireless inertial sensors (Xsens) mounted on the head and torso. Eye movements were recorded while subjects viewed near (0.5m) and far (approximately 4m) targets, and then imagined these targets in darkness. Subjects also provided perceptual estimates of target distances. Consistent with the kinematic properties shown in previous studies, the tVOR gain was greater with near targets, and greater with vision than in darkness. We conclude that this portable chair system can provide a field measure of otolith-ocular function at frequencies sufficient to elicit a robust tVOR.

  18. Geographical origin of Amazonian freshwater fishes fingerprinted by ⁸⁷Sr/⁸⁶Sr ratios on fish otoliths and scales.

    Science.gov (United States)

    Pouilly, Marc; Point, David; Sondag, Francis; Henry, Manuel; Santos, Roberto V

    2014-08-19

    Calcified structures such as otoliths and scales grow continuously throughout the lifetime of fishes. The geochemical variations present in these biogenic structures are particularly relevant for studying fish migration and origin. In order to investigate the potential of the (87)Sr/(86)Sr ratio as a precise biogeochemical tag in Amazonian fishes, we compared this ratio between the water and fish otoliths and scales of two commercial fish species, Hoplias malabaricus and Schizodon fasciatus, from three major drainage basins of the Amazon: the Madeira, Solimões, and Tapajós rivers, displaying contrasted (87)Sr/(86)Sr ratios. A comparison of the (87)Sr/(86)Sr ratios between the otoliths and scales of the same individuals revealed similar values and were very close to the Sr isotopic composition of the local river where they were captured. This indicates, first, the absence of Sr isotopic fractionation during biological uptake and incorporation into calcified structures and, second, that scales may represent an interesting nonlethal alternative for (87)Sr/(86)Sr ratio measurements in comparison to otoliths. Considering the wide range of (87)Sr/(86)Sr variations that exist across Amazonian rivers, we used variations of (87)Sr/(86)Sr to discriminate fish origin at the basin level, as well as at the sub-basin level between the river and savannah lakes of the Beni River (Madeira basin).

  19. Multi-element otolith chemistry of juvenile sole ( Solea solea), whiting ( Merlangius merlangus) and European seabass ( Dicentrarchus labrax) in the Thames Estuary and adjacent coastal regions

    Science.gov (United States)

    Leakey, Chris D. B.; Attrill, Martin J.; Fitzsimons, Mark F.

    2009-04-01

    Estuaries are regarded as valuable nursery habitats for many commercially important marine fishes, potentially providing a thermal resource, refuge from predators and a source of abundant prey. To assess the extent of estuarine use by juvenile (0+) common sole ( Solea solea), whiting ( Merlangius merlangus) and European seabass ( Dicentrarchus labrax) we: (1) developed techniques to distinguish between estuarine and coastally-caught juveniles using otolith chemistry; and (2) examined the accuracy with which multi-elemental signatures could re-classify juveniles to their region of collection. High-resolution solution-based inductively coupled plasma mass spectrometry (HB-SB-ICPMS) was used to quantify 32 elements within the juvenile otoliths; 14 elements occurred above detection limits for all samples. Some elemental distributions demonstrated clear differences between estuarine and coastally-caught fish. Multivariate analysis of the otolith chemistry data resulted in 95-100% re-classification accuracy to the region of collection. Estuarine and coastal signatures were most clearly defined for sole which, compared to bass and whiting, have low mobility and are less likely to move from estuarine to coastal habitats between larval settlement and later migration to adult stocks. Sole were the only species to reveal an energetic benefit associated with an estuarine juvenile phase. The physiological ability of bass to access upper estuarine regions was consistent with some elemental data, while the high mobility and restricted range of whiting resulted in less distinct otolith chemistries.

  20. Linking growth to environmental histories in central Baltic young-of-the-year sprat, Sprattus sprattus : an approach based on otolith microstructure analysis and hydrodynamic modelling

    DEFF Research Database (Denmark)

    Baumann, H.; Hinrichsen, H.H.; Voss, R.;

    2006-01-01

    Otolith microstructure analysis and hydrodynamic modelling were combined to study growth patterns in young-of-the-year (YoY) sprat, Sprattus sprattus, which were sampled in October 2002 in the central Baltic Sea. The observed 'window of survival', approximated by the distribution of back-calculat...

  1. Is otolith microchemistry (Sr: Ca and Ba:Ca ratios) useful to identify Mugil curema populations in the southeastern Caribbean Sea?

    Science.gov (United States)

    Avigliano, E; Callicó-Fortunato, R; Buitrago, J; Volpedo, A V

    2015-11-01

    The aim of the present study was to evaluate the potential use of otolith microchemistry (Sr:Ca and Ba:Ca ratios) to identify silver mullet, Mugil curema, populations in Southeastern Caribbean Sea. Fish samples were collected in 7 areas of Nueva Esparta State (Venezuela). The otolith Sr:Ca and Ba:Ca ratios and water Sr:Ca were determined (by ICP-OES and EDTA volumetric method). Otoliths Sr:Ca and Ba:Ca ratios and Sr:Ca partition coefficient of mullets in Cubagua island (south of the State) were significantly different from ratios in La Guardia (north of the State). A discriminant analysis of otolith Sr:Ca and Ba:Ca ratios separated Cubagua Island from La Guardia values. These results suggest the existence of different mullet groups in the Southeastern Caribbean Sea. For this, the simultaneous use of Sr:Ca and Ba:Ca ratios could be a potential tool to identify populations in the study area. PMID:26628220

  2. A novel length back-calculation approach accounting for ontogenetic changes in the fish length - otolith size relationship during the early life of sprat (Sprattus sprattus)

    DEFF Research Database (Denmark)

    Guenther, Claudia C.; Temming, Axel; Baumann, Hannes;

    2012-01-01

    An individual-based length back-calculation method was developed for juvenile Baltic sprat (Sprattus sprattus), accounting for ontogenetic changes in the relationship between fish length and otolith length. In sprat, metamorphosis from larvae to juveniles is characterized by the coincidence of low...

  3. Potential effects of hydroelectric dam development in the Mekong River basin on the migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus elucidated by otolith microchemistry.

    Directory of Open Access Journals (Sweden)

    Michio Fukushima

    Full Text Available The migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus, two of the most economically important fish species in the Mekong River, was studied using an otolith microchemistry technique. Fish and river water samples were collected in seven regions throughout the whole basin in Thailand, Laos and Cambodia over a 4 year study period. There was coherence between the elements in the ambient water and on the surface of the otoliths, with strontium (Sr and barium (Ba showing the strongest correlation. The partition coefficients were 0.409-0.496 for Sr and 0.055 for Ba. Otolith Sr-Ba profiles indicated extensive synchronized migrations with similar natal origins among individuals within the same region. H. siamensis movement has been severely suppressed in a tributary system where a series of irrigation dams has blocked their migration. H. lobatus collected both below and above the Khone Falls in the mainstream Mekong exhibited statistically different otolith surface elemental signatures but similar core elemental signatures. This result suggests a population originating from a single natal origin but bypassing the waterfalls through a passable side channel where a major hydroelectric dam is planned. The potential effects of damming in the Mekong River are discussed.

  4. Beyond the transect: An alternative microchemical imaging method for fine scale analysis of trace elements in fish otoliths during early life

    International Nuclear Information System (INIS)

    Microchemical analysis of otolith (calcified ‘ear stones’ used for balance and orientation) of fishes is an important tool for studying their environmental history and management. However, the spatial resolution achieved is often too coarse to examine short-term events occurring in early life. Current methods rely on single points or transects across the otolith surface, which may provide a limited view of elemental distributions, a matter that has not previously been investigated. Imaging by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) permits microchemical analyses of short-term events in early life with high (< 10 μm) resolution, two-dimensional (2D) visualization of elemental distributions. To demonstrate the potential of this method, we mapped the concentrations of Sr and Ba, two key trace elements, in a small number of juvenile otoliths of neon damselfish (Pomacentrus coelestis) using an 8 μm beam diameter (laser fluence of 13.8 ± 3.5 J cm−2). Quantification was performed using the established method by Longerich et al. (1996), which is applied to 2D imaging of a biological matrix here for the first time. Accuracy of > 97% was achieved using a multi-point non matrix-matched calibration of National Institute of Standards and Technology (NIST) 610 and 612 (trace elements in glass) using Longerich's calculation method against the matrix-matched standard FEBS-1 (powdered red snapper [Lutjanus campechanus] otolith). The spatial resolution achieved in the otolith corresponded to a time period of 2 ± 1 days during the larval phase, and 4 ± 1 days during the post-settlement juvenile phase. This method has the potential to improve interpretations of early life-history events at scales corresponding to specific events. While the images showed gradients in Sr and Ba across the larval settlement zone more clearly than single transects, the method proved sample homogeneity throughout the structure; demonstrating that 2D scanning

  5. Beyond the transect: An alternative microchemical imaging method for fine scale analysis of trace elements in fish otoliths during early life

    Energy Technology Data Exchange (ETDEWEB)

    McGowan, Nicole [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); CCFS ARC Centre of Excellence, Department of Earth and Planetary Sciences, Macquarie University, Sydney (Australia); Fowler, Ashley M.; Parkinson, Kerryn [Fish Ecology Laboratory, School of the Environment, University of Technology, Sydney, New South Wales (Australia); Bishop, David P. [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); Ganio, Katherine [Florey Department of Neuroscience and Mental Health, University of Melbourne, Victoria (Australia); Doble, Philip A. [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); Booth, David J. [Fish Ecology Laboratory, School of the Environment, University of Technology, Sydney, New South Wales (Australia); Hare, Dominic J., E-mail: dominic.hare@uts.edu.au [Elemental Bio-imaging Facility, University of Technology, Sydney, New South Wales (Australia); Florey Department of Neuroscience and Mental Health, University of Melbourne, Victoria (Australia)

    2014-10-01

    Microchemical analysis of otolith (calcified ‘ear stones’ used for balance and orientation) of fishes is an important tool for studying their environmental history and management. However, the spatial resolution achieved is often too coarse to examine short-term events occurring in early life. Current methods rely on single points or transects across the otolith surface, which may provide a limited view of elemental distributions, a matter that has not previously been investigated. Imaging by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) permits microchemical analyses of short-term events in early life with high (< 10 μm) resolution, two-dimensional (2D) visualization of elemental distributions. To demonstrate the potential of this method, we mapped the concentrations of Sr and Ba, two key trace elements, in a small number of juvenile otoliths of neon damselfish (Pomacentrus coelestis) using an 8 μm beam diameter (laser fluence of 13.8 ± 3.5 J cm{sup −2}). Quantification was performed using the established method by Longerich et al. (1996), which is applied to 2D imaging of a biological matrix here for the first time. Accuracy of > 97% was achieved using a multi-point non matrix-matched calibration of National Institute of Standards and Technology (NIST) 610 and 612 (trace elements in glass) using Longerich's calculation method against the matrix-matched standard FEBS-1 (powdered red snapper [Lutjanus campechanus] otolith). The spatial resolution achieved in the otolith corresponded to a time period of 2 ± 1 days during the larval phase, and 4 ± 1 days during the post-settlement juvenile phase. This method has the potential to improve interpretations of early life-history events at scales corresponding to specific events. While the images showed gradients in Sr and Ba across the larval settlement zone more clearly than single transects, the method proved sample homogeneity throughout the structure; demonstrating that 2D

  6. Daily otolith growth and ontogenetic geochemical signatures of age-0 anchovy (Engraulis encrasicolus in the Gulf of Cádiz (SW Spain.

    Directory of Open Access Journals (Sweden)

    I. A. CATALÁN

    2015-01-01

    Full Text Available The European anchovy fishery in the Gulf of Cádiz (ICES Division IXa South is largely influenced by age-0 individuals. Knowledge of young of the year growth dynamics is crucial for management, yet data on daily growth are lacking in the area. Linking growth patterns to the environment requires information on habitat occupancy through ontogeny of the fish that reach the fishery, as anchovy use different areas of the Gulf and the Guadalquivir Estuary through development. We describe the growth dynamics of age-0 anchovy through otolith microstructure analysis, and couple these data with data on microchemical signals in the otoliths to shed light into habitat use and growth dynamics in the area. Age-0 anchovy captured in September, 2011 in the Gulf ranged from 3 to 6 months old for similar sizes, with average growth rates varying twofold. Individual non-linear growth curves showed that maximum otolith growth was positively correlated with the date of spawning, which in turn was negatively correlated with the time to reach maximum growth. There was no correlation between growth parameters and body length or condition (Fulton K at capture. The strontium:calcium (Sr/Ca and magnesium:calcium (Mg/Ca ratios were significantly lower at the edge of the otolith (approximately the age of capture than at ages corresponding to larval and early juveniles (<60 days old, but values fell within typical estuarine-dwelling species. The barium:calcium ratio (Ba/Ca increased significantly in the edge of the otolith, which possibly resulted from residency in highly productive coastal waters or from ontogenetic effects. The variance in otolith elemental ratios was larger at otolith back-calculated ages around 50 days old, age which coincides with the presumed closer dependence of estuarine waters. Our data are a first step towards understanding the contribution of the estuarine system to the fishery of anchovy in the Gulf. The limitations of the approach and future

  7. Effects of ocean acidification on growth and otolith condition of juvenile scup, Stenotomus chrysops from laboratory experiment studies from 2011-08-24 to 2011-10-19 (NODC Accession 0117506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains laboratory experiment data that were collected to examine the effects of elevated levels of CO2 on the growth, survival, otolith (ear...

  8. Otolith growth of Springer's demoiselle, Chrysiptera springeri (Pomacentridae, Allen & Lubbock), on a protected and non-protected coral reef

    DEFF Research Database (Denmark)

    Retzel, A.; Hansen, A.D.; Grønkjær, P.

    2007-01-01

    The structural complexity of coral reefs is important for their function as shelter and feeding habitats for coral reef fishes, but physical disturbance by human activities often reduce complexity of the reefs by selectively destroying fragile and more complex coral species. The damselfish Springer......'s demoiselle Chrysiptera springeri primarily utilize complex coral heads for shelter and are hence vulnerable to human disturbance. In order to evaluate the potential effect of habitat degradation on juvenile fish growth, coral reef cover, fish age at settling and otolith growth, juvenile Springer's demoiselle...... was investigated on a protected and non-protected coral reef in Darvel Bay, Borneo. The protected reef had higher coverage of complex branching corals and exhibited a more complex 3-dimensional structure than the non-protected reef. Springer's demoiselle settled at the same age on non-protected and protected reefs...

  9. OTOLITH MICROCHEMISTRY INDICATES UNEXPECTED PATTERNS OF RESIDENCY AND ANADROMY IN BLUEBACK HERRING, ALOSA AESTIVALIS, IN THE HUDSON AND MOHAWK RIVERS.

    Directory of Open Access Journals (Sweden)

    LIMBURG K. E.

    2001-07-01

    PIXE, providing a detailed time series of data on the Sr:Ca, and thus habitat use history, of the fish. We also analyzed otoliths of Mohawk and Hudson River young-of-year (YOY. The Sr:Ca ratios of Mohawk YOY are slightly but significantly higher than those of Hudson YOY. Life history transects for 51 adults show complex patterns of Sr:Ca, indicating that many of the fish move into salt water at least for brief periods. However, many fish appear to spend extended parts of their post-YOY lives in fresh water, and at least two adults (caught in the Mohawk near Rome, NY appear never to have changed habitats at all. This is thus the first demonstration of residency in Mohawk River herring.

  10. Otolith analysis of pre-restoration habitat use by Chinook salmon in the delta-flats and nearshore regions of the Nisqually River Estuary

    Science.gov (United States)

    Lind-Null, Angie; Larsen, Kim

    2010-01-01

    The Nisqually Fall Chinook population is one of 27 salmon stocks in the Puget Sound (Washington) evolutionarily significant unit listed as threatened under the federal Endangered Species Act (ESA). Extensive restoration of the Nisqually River delta ecosystem is currently taking place to assist in recovery of the stock as juvenile Fall Chinook salmon are dependent on the estuary. A pre-restoration baseline that includes the characterization of life history strategies, estuary residence times, growth rates, and habitat use is needed to evaluate the potential response of hatchery and natural origin Chinook salmon to restoration efforts and to determine restoration success. Otolith analysis was selected as a tool to examine Chinook salmon life history, growth, and residence in the Nisqually River estuary. Previously funded work on samples collected in 2004 (marked and unmarked) and 2005 (unmarked only) partially established a juvenile baseline on growth rates and length of residence associated with various habitats (freshwater, forested riverine tidal, emergent forested transition, estuarine emergent marsh, delta-flats and nearshore). However, residence times and growth rates for the delta-flats (DF) and nearshore (NS) habitats have been minimally documented due to small sample sizes. The purpose of the current study is to incorporate otolith microstructural analysis using otoliths from fish collected within the DF and NS habitats during sampling years 2004-08 to increase sample size and further evaluate between-year variation in otolith microstructure. Our results from this analysis indicated the delta-flats check (DFCK) on unmarked and marked Chinook samples in 2005-08 varied slightly in appearance from that seen on samples previously analyzed only from 2004. A fry migrant life history was observed on otoliths of unmarked Chinook collected in 2005, 2007, and 2008. Generally, freshwater mean increment width of unmarked fish, on average, was smaller compared to marked

  11. Evaluation of otolith shape as a tool for stock discrimination in marine fishes using Baltic Sea cod as a case study

    DEFF Research Database (Denmark)

    Hüssy, Karin; Mosegaard, Henrik; Albertsen, Christoffer Moesgaard;

    2016-01-01

    SNP (singlenucleotide polymorphism) based genetic assignment of otolith shape baselines. We further developeda management aimed approach for mixed stock assignment by robust stochastic baseline selection andposterior bias correction by individual reassignment of the least likely classifications......In the Western Baltic Sea two genetically distinct cod stocks “Eastern Baltic cod” and “Western Balticcod” occur with considerable mixing of stocks. In this study we evaluated the applicability of otolithshape analysis for classification of individuals caught in the mixed stock cod fishery, using...... into the alternatestock. Classification criteria selected by Monte Carlo runs of Linear Discriminant Analysis were capturedby otolith area and 20 Elliptic Fourier Descriptors of primarily low frequency harmonics. Classificationsuccess was considerably lower when using a baseline of spawning individuals only, compared...

  12. Vestibular Stimulation for ADHD: Randomized Controlled Trial of Comprehensive Motion Apparatus

    Science.gov (United States)

    Clark, David L.; Arnold, L. Eugene; Crowl, Lindsay; Bozzolo, Hernan; Peruggia, Mario; Ramadan, Yaser; Bornstein, Robert; Hollway, Jill A.; Thompson, Susan; Malone, Krista; Hall, Kristy L.; Shelton, Sara B.; Bozzolo, Dawn R.; Cook, Amy

    2008-01-01

    Objective: This research evaluates effects of vestibular stimulation by Comprehensive Motion Apparatus (CMA) in ADHD. Method: Children ages 6 to 12 (48 boys, 5 girls) with ADHD were randomized to thrice-weekly 30-min treatments for 12 weeks with CMA, stimulating otoliths and semicircular canals, or a single-blind control of equal duration and…

  13. 金枪鱼类耳石微化学研究进展%Otolith microchemistry of tuna species: Research progress.

    Institute of Scientific and Technical Information of China (English)

    朱国平

    2011-01-01

    Microchemistry analysis of trace elements and isotopes in fishes' calcified substances is an emerging approach to analyze the population structure, life history, and migration environmental history of fishes. With the increasing improvement of the researches and applications of otolith microchemistry , this approach has been a good tool for studying the ecology of tuna species. Currently , the research contents of tuna species' otolith microchemistry mainly include trace elements and isotopes, and the former is the emphasis and hotspot in applied research, playing a vital role in the researches of population partitioning, natal origin, migration environmental history, and life history of tuna species, especially bluefin tuna. However, most of the researches are focusing on the variation of otolith' s Sr/Ca ratio, and there is no final conclusion on the relationships between the frac-tionation of isotopes C and 0 in otolith and the temperature. For the sake of exploiting the huge value of otolith microchemistry, it would be necessary to strengthen the researches on the deposition mechanisms of trace elements in otolith, and to analyze the spatio-temporal variations of various trace elements in otolith by comprehensive research methods.%近年来,基于鱼类钙化物质中微量元素和同位素等微化学成分分析已成为分析鱼类种群结构、生活史及洄游环境史等的一种新兴手段.随着鱼类耳石微化学研究及应用的日渐成熟与完善,该手段也日益成为金枪鱼类生态学研究的良好工具.目前金枪鱼类耳石微化学的研究内容主要包括微量元素和同位素等,其中微量元素是应用研究的重点和热点,其在金枪鱼类,尤其是蓝鳍金枪鱼种群划分、出生源、洄游环境史和生活史分析等方面发挥了重要的作用.但多数研究集中在耳石锶钙比率(Sr/Ca)的变化上,且关于耳石碳氧同位素分馏与温度之间的关系尚无定论.为了开

  14. Age and Growth of Chub Mackerel (Scomber japonicus) in the East China and Yellow Seas Using Sectioned Otolith Samples

    Institute of Scientific and Technical Information of China (English)

    LI Gang; CHEN Xinjun; FENG Bo

    2008-01-01

    Although chub mackerel (Scomberjaponicus) is a primary pelagic fish species,we have only limited knowledge on itskey life history processes.The present work studied the age and growth of chub mackerel in the East China and Yellow Seas.Agewas determined by interpreting and counting growth rings on the sagitta otoliths of 252 adult fish caught by the Chinese commercialpurse seine fleet during the period from November 2006 to January 2007 and 150 juveniles from bottom trawl surveys on the spawn-ing ground in May 2006.The difference between the assumed birth date of 1 st April and date of capture was used to adjust the agedetermined from counting the number of complete translucent rings.The parameters of three commonly used growth models,the vonBertalanffy,Logistic and Gompertz models,were estimated using the maximum likelihood method.Based on the Akaike InformationCriterion (AIC),the von Bertalanffy growth model was found to be the most appropriate model.The size-at-age and size-at-maturityvalues were also found to decrease greatly compared with the results achieved in the 1950s,which was caused by heavy exploitationover the last few decades.

  15. Age and growth of chub mackerel ( Xcomber japonicus) in the East China and Yellow Seas using sectioned otolith samples

    Science.gov (United States)

    Li, Gang; Chen, Xinjun; Feng, Bo

    2008-11-01

    Although chub mackerel ( Scomber japonicus) is a primary pelagic fish species, we have only limited knowledge on its key life history processes. The present work studied the age and growth of chub mackerel in the East China and Yellow Seas. Age was determined by interpreting and counting growth rings on the sagitta otoliths of 252 adult fish caught by the Chinese commercial purse seine fleet during the period from November 2006 to January 2007 and 150 juveniles from bottom trawl surveys on the spawning ground in May 2006. The difference between the assumed birth date of 1st April and date of capture was used to adjust the age determined from counting the number of complete translucent rings. The parameters of three commonly used growth models, the von Bertalanffy, Logistic and Gompertz models, were estimated using the maximum likelihood method. Based on the Akaike Information Criterion ( AIC), the von Bertalanffy growth model was found to be the most appropriate model. The size-at-age and size-at-maturity values were also found to decrease greatly compared with the results achieved in the 1950s, which was caused by heavy exploitation over the last few decades.

  16. Solid phase extraction for analysis of biogenic carbonates by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS): an investigation of rare earth element signatures in otolith microchemistry

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Zikri; Paulson, Anthony J

    2003-01-10

    Uptake of trace elements into fish otoliths is governed by several factors such as life histories and environment in addition to stock and species differences. In an attempt to elucidate the elemental signatures of rare earth elements (REEs) in otoliths, a solid phase extraction (SPE) protocol was used in combination with electrothermal vaporization (ETV) as a sample introduction procedure for the determinations by inductively coupled plasma quadrupole mass spectrometry (ICP-MS). Effects of various parameters, such as carrier gas flow rate, atomization temperature and chemical modification, were examined for optimization of the conditions by ETV-ICP-MS. Atomization was achieved at 2800 deg. C. Lower temperatures (i.e. 2600 deg. C) resulted in severe memory problems due to incomplete atomization. Palladium was used as a chemical modifier. It was found that an increase in Pd concentration up to 0.5 {mu}g in the injection volume (70 {mu}l) led up to four-fold enhancement in the integrated signals. This phenomenon is attributed to the carrier effect of Pd rather than the stabilization since no significant losses were observed for high temperature drying around 700 deg. C even in the absence of Pd. Preconcentration was performed on-line at pH 5 by using a mini-column of Toyopearl AF-Chelate 650M chelating resin, which also eliminated the calcium matrix of otolith solutions. After preconcentration of 6.4 ml of solution, the concentrate was collected in 0.65 ml of 0.5% (v/v) HNO{sub 3} in autosampler cups, and then analyzed by ETV-ICP-MS. The method was validated with the analysis of a fish otolith certified reference material (CRM) of emperor snapper, and then applied to samples. Results obtained from otoliths of fish captured in the same habitat indicated that otolith rare earth element concentrations are more dependent on environmental conditions of the habitat than on species differences.

  17. Growth changes in plaice, cod, haddock and saithe in the North Sea: a comparison of (post-)medieval and present-day growth rates based on otolith measurements

    Science.gov (United States)

    Bolle, Loes J.; Rijnsdorp, Adriaan D.; van Neer, Wim; Millner, Richard S.; van Leeuwen, Piet I.; Ervynck, Anton; Ayers, Richard; Ongenae, Ellen

    2004-05-01

    Fishing effort has strongly increased in the North Sea since the mid-19th century, causing a substantial reduction in the population size of exploited fish stocks. As fisheries research has developed simultaneously with the industrialisation of the fisheries, our knowledge of population dynamics at low levels of exploitations is limited. Otoliths retrieved from archaeological excavations offer a unique opportunity to study growth rates in the past. This study compares historical and present-day growth rates for four commercially important demersal fish species. A total of 2532 modern otoliths (AD 1984-1999) and 1286 historical otoliths (AD 1200-1925) obtained from archaeological excavations in Belgium and Scotland were analysed. Comparison of the growth patterns between eras revealed a major increase in growth rate of haddock, whereas growth changes were not observed in saithe and only in the smaller size classes of plaice and cod. Comparison of our results with literature data indicates that the observed growth rate changes in plaice and cod occurred within the 20th century. Apparently the onset of industrialised fisheries has not greatly affected the growth of plaice, cod and saithe populations in the North Sea. This result contradicts the expectation of density-dependent limitation of growth during the era of pre-industrialised fishing, but is in agreement with the concentration hypothesis of Beverton (Neth. J. Sea Res. 34 (1995) 1) stating that species which concentrate spatially into nursery grounds during their early life-history may 'saturate' the carrying capacity of the juvenile habitat even though the adult part of the population is not limited by the adult habitat.

  18. Morphology of bigeye tuna otolith in waters near Marshall Islands%马绍尔群岛海域大眼金枪鱼耳石形态

    Institute of Scientific and Technical Information of China (English)

    宋利明; 吕凯凯; 杨嘉樑; 胡振新

    2012-01-01

    耳石是鱼类生态的重要信息载体。根据2009年11月-2010年1月马绍尔群岛海域采集的大眼金枪鱼(Thunnus obesus)样本中获得的222对矢耳石,对其形态特征进行观察和测量。观察发现,矢耳石上有3条凹沟,可将矢耳石分为背区、翼区、吻区和侧区4个区。t检验表明,左右矢耳石形态参数无显著性差异(P=0.999)。对矢耳石12个形态参数作主成分分析,结果显示,背区长(DL)、翼区前长(WFL)、翼区长(WL)和最大厚度(MST)可以代表矢耳石尺度特征,背区夹角(DA)和翼区夹角(WA)代表矢耳石角度特征。DL与MST的关系可用指数表达,叉长(FL)与DL间可用多项式表达、叉长与WFL和矢耳石重量(OW)间可用逻辑斯蒂克模型表达。随叉长增加,矢耳石核心向背区、侧区和吻区方向移动。对不同DL组的DA进行多重比较分析,发现DA在DL为500~700μm间出现生长波动,结合FL与DL之间关系,认为大眼金枪鱼初次性成熟时DL为600μm左右,叉长在80~130 cm之间。%The otolith of fish is an important source of ecological information.It is a popular and successful tool in discriminating between and within fish stocks to study the morphologic characteristics of the otolith.A total of 222 pairs of sagittal otolith were collected randomly from Nov.2009 through Jan.2010 in waters near Marshall Islands.The morphologic characteristics of them were observed and measured.There were three channels on them which divide the sagittal otolith four areas(dorsum,wing,rostrum,and lateral).There was no significant difference between the morphological parameters of the left sagitta and the right sagitta(P=0.999).The result of principal component analysis on 12 morphologic parameters showed the dorsal length(DL),wing front length(WFL),wing length(WL) and maximum statolith thickness(MST) can be used to represent the size features of the sagittal otolith;the dorsal angle

  19. Length-weight relationships and relative conditions of two sciaenids Otolithes cuvieri Trewavas and Johnius elongatus Mohan from the Karachi coast

    OpenAIRE

    Shamsul Hoda, S.M.; Ajazuddin, S.

    1993-01-01

    Estimates of length-weight relationship in Otolithes cuvieri justify separate equations for males (log W =-5.0100+3.1365 log L) and females (log W =-5.2000+3.1006 log L). Relative condition factor "Kn" was found to be 0.877-1.946 in males and 0.879-1.328 in females. High "Kn" values during March to September at 180-220 mm TL in either sexes are indicative of the maturation of gonads. Separate equations for length-weight relationship are also justified for males (log W = -5.1126 + 3.0690 log L...

  20. Some aspects of reproductive biology of two sciaenids, Otolithes cuvieri Trewavas and Johnius elongatus Mohan: maturation, spawning, sex ratio and fecundity

    OpenAIRE

    Shamsul Hoda, S.M.; Ajazuddin, S.

    1992-01-01

    The gonads of Otolithes cuvieri and Johnius elongatus are described in seven maturity stages. O. Cuvieri spawns once a year from April to September as evidence by ova diameter frequency distribution and GSI values. 50% maturity is attained at 210mm TL in males and 200mm TL in females. Fecundity ranged from 2387 to 104379 with a mean value of 33502. Log-Log relationship between fecundity and total lenght, body weight and ovary weight were determined. An overall sex ratio of 1.54:1.00 was unequ...

  1. Stable isotope compositions (O-C) of reef fish otoliths from the Taiaro lagoon (Tuamotu, French Polynesia): isotopic and biologic implications

    International Nuclear Information System (INIS)

    Nuclei (larval stage) and outer parts (adult stage) of fish otoliths from the Taiaro closed lagoon (French Polynesia) and adjacent ocean have been analysed for the C-O isotopic compositions. δ18O values of the nuclei of both populations indicate that isotopic equilibrium is reached. This implies that the lagoonal fish population has done its complete biological cycle in the lagoon and represents an adaptation in a closed system. δ18O values of the outer parts show a slight isotopic disequilibrium (13C values exhibit a strong isotopic disequilibrium related to metabolic activity. (authors)

  2. 西北印度洋丝尾红钻鱼耳石生长形态学的初步研究%Otolith morphology of ruby snapper Etelis coruscans in the northwestern Indian Ocean

    Institute of Scientific and Technical Information of China (English)

    林东明; 许柳雄; 叶旭昌; 王学昉; 朱国平

    2015-01-01

    根据2005年10月至2006年1月在印度洋公海撒雅德玛哈浅滩(Saya de Malha Bank)进行底层渔业资源调查期间, 随机采集的208尾丝尾红钻鱼Etelis coruscans(叉长383~866 mm)样本, 进行了耳石质量(WO)及其耳石长(长轴, OTL)、 耳石宽(短轴, OW)、 背长(ODL)、 背高(DH)、 背喙长(DRL)和腹喙长(VRL)等形态指标参数的测定, 初步研究了该种群耳石形态指标的生长特征.结果表明: 丝尾红钻鱼左右矢耳石的长度和质量均无显著性差异或一致性偏差(P>0.05), 耳石呈缺刻卵圆形, 凸面有沟裂, 凹面核心区表面平坦; 背部和腹部边缘有不规则的齿轮缺刻; 腹喙比背喙长且粗壮; 耳石长轴(OTL)为9.85~20.76 mm, 短轴(OW)为5.03~10.88 mm; 叉长540 mm时, 耳石形态长度指标(OTL、 ODL)相对尺寸变化趋势不稳定, 而宽度指标相对尺寸变化趋势平缓; 整个生长过程中, 耳石短轴生长比其长轴生长稳定, 短轴与耳石质量的回归关系最高, 并且与鱼体叉长的关系基本符合正相关关系.因此, 丝尾红钻鱼的耳石短轴更适合用于耳石形态生长与耳石质量及鱼体生长关系的研究.%The weight and morphological characters of sagittal otoliths including otolith length(OTL), otolith width(OW), otolith dorsal length(ODL), otolith dorsal width(DH), ventral length(VRL), and dorsal length(DRL)were measured in the 208 specimens of ruby snapper Etelis coruscans(fork length 383-866 mm)collected from Saya de Malha bank in the northwestern Indian Ocean by bottom fisheries resources survey from October 2005 to January 2006.The left sagittal otolith was used in this study because there was no significant difference in otolith weight and morphology in pairs by t-test.The sagittal otolith is ovate in shape with a notch in the anterior, sulcus over the convexity, flat in the concave mesial surface, irregular dorsal margin and ventral margin, rostrum broad and antirostrum small, and had length of

  3. North Atlantic ecosystem shifts revealed by cod otolith δ15N and δ13C chronologies

    DEFF Research Database (Denmark)

    Pedersen, Jens Brøgger; Nielsen, Jens Munk; Steingrund, Petur;

    Changes in climate and exploitation have caused large fluctuations in the productivity of many North Atlantic cod populations and the collapse of many cod fisheries. These fluctuations are most likely due to a combined effect of physical processes and changes in ecosystem trophic structure. To...... study the link between environmental changes and ecosystem trophic structure we developed δ15N and δ13C chronologies by analyzing the organic matrix of cod otoliths from the Faroe Shelf cod population (1950-2010) and the Nuuk Fjord cod population (1927-2009). Significant correlations between δ15N & δ13C...... annual mean values over time were seen in both ecosystems, suggesting δ15N & δ13C values were affected by the same overall processes. There were significant effects of climate variables (temperature, Atlantic Multi-decadal Oscillation (AMO) and Sub Polar Gyre index) on δ15N and δ13C chronologies in both...

  4. Whitemouth croaker, Micropogonias furnieri, trapped in a freshwater coastal lagoon: a natural comparison of freshwater and marine influences on otolith chemistry

    Directory of Open Access Journals (Sweden)

    Cristiano Q. de Albuquerque

    2010-01-01

    Full Text Available Strontium and barium incorporation into otoliths was compared between whitemouth croaker, Micropogonias furnieri, collected from an entrapped freshwater population (Mirim Lagoon and a normal marine/estuarine population in southern Brazil. Chemical analysis was performed using LA-ICPMS with the objective of validating the effects of marine and freshwater environments on Sr and Ba incorporation as a basis for further investigation of marine and freshwater connectivity of M. furnieri. The freshwater population was dominated by older fish with mean ±SD age of 34±1 y, whereas the coastal samples were dominated by younger fish of 14±7 y. Comparison of strontium and barium incorporation among otolith life-history profiles indicated significantly higher barium and lower strontium for the freshwater population compared to the marine population. Furthermore, comparison of otolith material deposited in the freshwater, estuarine and marine life-history phases demonstrated clear differences among these environments. Mean concentrations of strontium and barium in otoliths of M. furnieri were respectively 710 and 112 µg g-1 for freshwater, 2069 and 16.7 µg g-1 for estuarine, and 2990 and 2.7 µg g-1 for marine life-history phases. Barium concentrations in otoliths from the freshwater population of M. furnieri appeared high relative to other freshwater species. Strontium levels across life-history profiles of marine fish increased with age from 2000 to 2900 µg g-1, possibly indicating more time spent in marine than estuarine waters with age. In contrast, for the freshwater population, strontium levels decreased during the first year of life approximately to 700 µg g-1, and remained low and stable thereafter, consistent with the early life-history occurring in an estuarine environment prior to entrapment in Mirim Lagoon. The results confirm the strong and opposite effects of marine and freshwater environments on incorporation of barium and strontium into

  5. Sagittal otolith morphology and daily increment analysis of Setipinna taty from L(u)si Fishing Ground%吕四渔场黄鲫耳石形态及日龄分析

    Institute of Scientific and Technical Information of China (English)

    张健; 刘必林; 陈小康; 彭永章

    2011-01-01

    根据2009年5月在吕四渔场单桩张网采集的231尾黄鲫幼鱼,对其耳石形态和储存信息进行分析.结果显示,耳石全长范围为1.88~4.91 mm,平均3.75mm;耳石重量范围为0.8~13.7 mg,平均6.4 mg.黄鲫耳石全长和叉长拟合生长方程为LOA=2.6322 ln(L)-8.2612.耳石全长与耳石重量关系式为WO=0.196×LOA-2.6186.黄鲫年龄范围为60~258 d,优势年龄组为90~150 d,占总体的69.5%;叉长与年龄拟合线性生长方程为L=0.2034 ×A+69.12.孵化日期为1月至3月,主要集中在2月份,占总体的83.6%.%231 Setipinna taty individuals were sampled by single-stake stownet fishery from Ltsi Fishing Ground in the south of the Yellow Sea to analyze sagittal otolith morphology and information contained. The results indicated that the otolith length ranged from 1.88 to 4.91 mm with mean of 3.75 mm and otolith weight ranged from 0.8 to 13.7 mg with mean of 6.4mg. Observation of the otoliths of Setipinna taty showed that the growth equation was fitted by the all otolith length (LoA, mm) and fork length as follows, LOA =2.6322 In(L) -8. 2612. The relationship between LoA and otolith weight (Wo, mg) was Wo =0. 196 ×OAL-2.6186. It is induced that the age range of the Setipinna taty individuals measured was 60 -258 days, in which 90 ~ 150 days dominated the age range, accounting for 69.5%. The linear growth equation between fork length and age (day) was L =0. 2034 ×A + 69.12. The estimated hatch dates of Setipinna taty in the south of the Yellow Sea were distributed between January and March and 83.6% concentrated in February.

  6. Estimating the proportion of river and sea spawning whitefish in catches from the brackish Gulf of Bothnia (Baltic Sea by gill raker counting, genotyping and otolith chemistry analysis

    Directory of Open Access Journals (Sweden)

    Henry Hägerstrand

    2015-11-01

    Full Text Available European whitefish (Coregonus lavaretus is a commercially and recreationally important species in the Gulf of Bothnia (Figure 1, where the salinity of the surface water increases from ~2 ‰ to ~6 ‰ in the north-south (~725 km direction. Two sympatric ecotypes with similar outer features occur: stationary sea spawning whitefish and migrating anadromous river spawning whitefish (Lehtonen 1981. The two types mix in sea away from breeding locations and off breeding time. River spawning whitefish can undertake long feeding and spawning migrations, e.g. between the north and the south of the gulf. The river spawning whitefish abundantly occur at feeding grounds in the south where they stay for years, until maturing. Mainly due to anthropogenic destruction of the spawning rivers, the river spawning whitefish has diminished during last decades and is presently listed among endangered species (Helcom 2013. A reliable assessment of the two ecotypes and their subpopulations is a prerequisite for taking effective actions for stock preservation. In order to compare methods for whitefish ecotype identification we undertook genotyping, otolith chemistry analysis and gill raker counting on river and sea spawning whitefish populations. Materials and methods. Whitefish to undergo spawning was sampled from rivers along the Finnish west coast (river spawners and at sea from known spawning sites close to the southern feeding grounds at the Åland Islands and the Archipelago Sea (sea spawners (Himberg et al. 2015, Figure 1. Gill rakers were counted on the left outer arch. Data on gill raker number was also collected from literature. Genetic diversity was assessed by nine microsatellite markers (Ozerov et al. 2015. Two methods were used for otolith (sagittae chemistry analysis. Otoliths were dissolved and analyzed for elemental concentrations with ICP-OES (Hägerstrand et al. 2015, or polished to the core and analyzed for core strontium concentration by PIXE

  7. Analysis of biogenic carbonates by inductively coupled plasma-mass spectrometry (ICP-MS). Flow injection on-line solid-phase preconcentration for trace element determination in fish otoliths.

    Science.gov (United States)

    Arslan, Z; Paulson, A J

    2002-04-01

    The aragonite deposits within the ear bones (otoliths) of teleost fish retain a chemical signal reflecting the life history of fish (similar to rings of trees) and the nature of fish habitats. Otoliths dissolved in acid solutions contain high concentrations of calcium and a variety of proteins. Elimination of matrix salts and organic interferences during preconcentration is essential for accurate determination of trace elements in otolith solutions by inductively coupled plasma-quadrupole mass spectrometry. An iminodiacetate-based chelating resin (Toyopearl AF-Chelate 650 M) has been used for on-line preconcentration and matrix separation for the determination of 31 transition and rare elements. Successful preconcentration of the elements was achieved at pH 5 by on-line buffering, except Mn which required pH 8.8. Sample solutions were loaded on to the column for 1 min at 3.2 mL min(-1), and then eluted directly into the mass spectrometer with 4% v/v nitric acid. This procedure enabled up to 25-fold preconcentration with successful removal of the calcium matrix. The effect of heat-assisted oxidation with concentrated nitric acid was investigated to eliminate the organic matrix. It was found that heating to dryness after dissolution and further mineralization with the acid significantly improved the retention of the transition elements. The method was validated by analysis of a certified reference material produced from saggittal otoliths of emperor snapper ( Lutjanus sebae), and then applied to the determination of trace metal concentrations in juvenile bluefin tuna ( Thunnus thynnus) from the Western Pacific Ocean.

  8. Analysis of biogenic carbonates by inductively coupled plasma-mass spectrometry (ICP-MS). Flow injection on-line solid-phase preconcentration for trace element determination in fish otoliths

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Z.; Paulson, A.J. [National Oceanic and Atmospheric Administration (NOAA), Northeast Fisheries Science Center (NFSC), James J. Howard Marine Sciences Laboratory, Highlands, NJ (United States)

    2002-04-01

    The aragonite deposits within the ear bones (otoliths) of teleost fish retain a chemical signal reflecting the life history of fish (similar to rings of trees) and the nature of fish habitats. Otoliths dissolved in acid solutions contain high concentrations of calcium and a variety of proteins. Elimination of matrix salts and organic interferences during preconcentration is essential for accurate determination of trace elements in otolith solutions by inductively coupled plasma-quadrupole mass spectrometry. An iminodiacetate-based chelating resin (Toyopearl AF-Chelate 650 M) has been used for on-line preconcentration and matrix separation for the determination of 31 transition and rare elements. Successful preconcentration of the elements was achieved at pH 5 by on-line buffering, except Mn which required pH 8.8. Sample solutions were loaded on to the column for 1 min at 3.2 mL min{sup -1}, and then eluted directly into the mass spectrometer with 4% v/v nitric acid. This procedure enabled up to 25-fold preconcentration with successful removal of the calcium matrix. The effect of heat-assisted oxidation with concentrated nitric acid was investigated to eliminate the organic matrix. It was found that heating to dryness after dissolution and further mineralization with the acid significantly improved the retention of the transition elements. The method was validated by analysis of a certified reference material produced from saggittal otoliths of emperor snapper (Lutjanus sebae), and then applied to the determination of trace metal concentrations in juvenile bluefin tuna (Thunnus thynnus) from the Western Pacific Ocean. (orig.)

  9. Age estimations of wild pallid sturgeon (Scaphirhynchus albus, Forbes & Richardson 1905) based on pectoral fin spines, otoliths and bomb radiocarbon: inferences on recruitment in the dam-fragmented Missouri River

    Science.gov (United States)

    Braaten, P. J.; Campana, S. E.; Fuller, D. B.; Lott, R. D.; Bruch, R. M.; Jordan, G. R.

    2015-01-01

    An extant stock of wild pallid sturgeon Scaphirhynchus albus persists in the fragmented upper Missouri River basin of Montana and North Dakota. Although successful spawning and hatch of embryos has been verified, long-term catch records suggest that recruitment has not occurred for several decades as the extant stock lacks juvenile size classes and is comprised exclusively of large, presumably old individuals. Ages of 11 deceased (death years 1997–2007) wild S. albus (136–166 cm fork length) were estimated based on pectoral fin spines, sagittal otoliths and bomb radiocarbon (14C) assays of otoliths to test the hypothesis that members of this stock are old and to provide inferences on recruitment years that produced the extant stock. Age estimations based on counts of presumed annuli were about 2 years greater for otoliths (mean = 51 years, range = 43–57 years) than spines (mean = 49 years, range = 37–59 years). Based on 14C assays, confirmed birth years for all individuals occurred prior to 1957, thus establishing known longevity of at least 50 years. Estimated age based on presumed otolith annuli for one S. albus was validated to at least age 49. Although 14C assays confirmed pre-1957 birth years for all S. albus, only 56% of estimated ages from spines and 91% of estimated ages from otoliths depicted pre-1957 birth years. Both ageing structures were subject to under-ageing error (up to 15 years). Lack of or severe curtailment of S. albus recruitment in the upper Missouri River basin since the mid-1950s closely parallels the 1953–1957 timeframe when a mainstem reservoir was constructed and started to fill. This reservoir may function as a system-wide stressor to diminish recruitment success of S. albus in the upper Missouri River basin.

  10. Residence time and drift patterns of larval June sucker Chasmistes liorus in the lower Provo River as determined by otolith microstructure.

    Science.gov (United States)

    Ellsworth, C M; Belk, M C; Keleher, C J

    2010-08-01

    Estimates of age derived from daily ring counts from otoliths and capture rates of larval June sucker Chasmistes liorus were used to determine the relationship between discharge rates of the Provo River and residence time and patterns of larval drift. During 1997, larval drift occurred over a 22 day period when discharge rates were low (mean +/-s.d. 3.2 +/- 0.0 m(3) s(-1)). In 1998, larval drift occurred in two separate events over a 40 day period. Discharge was higher during the first larval drift period (19 days; 24.8 +/- 1.3 m(3) s(-1)) and lower during the second larval drift period (17 days; 7.0 +/- 0.9 m(3) s(-1)). In 1997, no larval fish were collected at the lowermost transect on the Provo River (nearest Utah Lake), and few larvae >21 days of age were found. During the first drift period of 1998, larval C. liorus were collected at all transects, and mean age of larvae collected between upstream and downstream transects increased by c. 7 days. During the second drift period of 1998, only a few were collected in the lowermost transects, and age did not increase with proximity to the lake. Patterns in catch and age distribution of larval C. liorus in the lower Provo River suggest that recruitment failure occurs during the larval drift period in years with insufficient discharge to transport larvae into the lake. PMID:20701638

  11. Patterns of primary growth increments in otoliths of Sparus aurata larvae in relation to water temperature and food consumption

    OpenAIRE

    Morales-nin, B; Gutiérrez Merino, Emilia; Massutí, Sofia

    1995-01-01

    Sparus aurata larvae reared under controlled water-temperature conditions during the first 24 days after hatching displayed a linear relationship between age (t) and standard length (SL): SL = 2.68 + 0.19 t (r2 = 0.91l). Increments were laid down in the sagittae with daily periodicity starting on day of hatching. Standard length (SL) and sagittae radius (OR) were correlated: SL(mm) = 2.65 + 0.012 OR(mm). The series of measurements of daily growth increment widths (DWI), food density and water...

  12. Ion microprobe Sr isotope analysis of carbonates with about 5 {mu}m spatial resolution: An example from an ayu otolith

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Yuji [Center for Advanced Marine Research, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639 (Japan)], E-mail: ysano@ori.u-tokyo.ac.jp; Shirai, Kotaro [International Coastal Research Center, Ocean Research Institute, University of Tokyo, Otsuchi, Iwate 028-1102 (Japan); Takahata, Naoto; Amakawa, Hiroshi [Center for Advanced Marine Research, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639 (Japan); Otake, Tsuguo [International Coastal Research Center, Ocean Research Institute, University of Tokyo, Otsuchi, Iwate 028-1102 (Japan)

    2008-08-15

    A high lateral resolution secondary ion mass spectrometer (NanoSIMS NS50 ion microprobe) has been used to measure {sup 87}Sr/{sup 86}Sr ratios in natural CaCO{sub 3} samples. A {approx}2 nA O{sup -} primary beam was used to sputter a 5-7-{mu}m diameter crater on the sample surface and secondary positive ions were extracted for mass analysis using an accelerating voltage of 8 kV and a Mattauch-Herzog geometry. The multi-collector system was adjusted to detect {sup 43}Ca{sup +} (by a detector EM2), {sup 80}Ca{sub 2}{sup +} (EM3), {sup 86}Sr{sup +} (EM4), and {sup 87}Sr{sup +} (EM4b) ions at the same time. Then the magnetic field was scanned for the EM4 to detect {sup 85}Rb{sup +}, {sup 86}Sr{sup +} and {sup 87}Sr{sup +}, while the EM4b can measure {sup 86}Sr{sup +}, {sup 87}Sr{sup +} and {sup 88}Sr{sup +}, respectively. A mass resolution of 3600 at 10% peak height was attained with a flat peak top, while the sensitivity of Sr was about 10 cps/nA/ppm. An aragonite sample (coral skeleton standard; JCp-1) was used as a reference for Sr isotope ratio calibration. Repeated analyses of the JCp-1 show that the {sup 87}Sr/{sup 86}Sr ratio agrees well with the seawater signature within a precision of 0.3 per mille at 2{sigma}, after the series of corrections such as the Ca dimer, {sup 87}Rb, and a mass bias estimated by the {sup 88}Sr/{sup 86}Sr ratio. The method was applied to an otolith (ear-stone) from ayu (Plecoglossus altivelis altivelis) collected from the Yodo river, Japan. Although experimental errors are relatively large, up to 3 per mille at 2{sigma}, the ratios of the core region are higher than the seawater signature while more distal values agree well with seawater. The very outermost part again shows the relatively higher {sup 87}Sr/{sup 86}Sr ratios. The spatial variation of {sup 87}Sr/{sup 86}Sr ratios was consistent with amphidromous migration of the fish, namely, born in the lake and grown in the coastal sea and finally collected in a river.

  13. Comparison of growth rates estimated by otolith reading of Scorpaena porcus and Scorpaena notata caught on artificial and natural reefs of the northern Adriatic sea

    Directory of Open Access Journals (Sweden)

    Giuseppe Scarcella

    2011-01-01

    Full Text Available Despite the high number of studies on fish assemblages associated with artificial reefs and offshore platforms, little information exists on the growth rates of fish living on artificial and natural substrates. Age and growth was determined throughout otolith reading on two commercial scorpionfishes (Scorpaena porcus and Scorpaena notata caught in the surroundings of artificial structures (artificial reefs and gas platforms and natural habitats. Von Bertalanffy growth parameters were calculated for each species separately for each site. Age of S. porcus and S. notata ranged from 0 to 8 years and from 0 to 16 years, respectively. Kimura test applied to Von Bertalanffy growth curves indicated that the individuals of both species inhabiting the artificial structures had higher growth parameters than those caught in the natural habitat. The presence of artificial habitats in the northern Adriatic Sea positively affects growth rates and growth performance of both species, likely for the greater prey availability in respect to the natural open sea.Apesar do elevado número de estudos sobre as assembléias de peixes associadas a recifes artificiais e plataformas offshore, existe pouca informação sobre as taxas de crescimento dos peixes que vivem em substratos artificiais e naturais. A idade e crescimento foram determinados pela leitura de otólitos em dois peixes escorpião comerciais (Scorpaena porcus e Scorpaena notata capturados nas imediações de estruturas artificiais (recifes artificiais e plataformas de gás e habitats naturais. Parâmetros de crescimento de von Bertalanffy foram calculadoss separadamente para cada espécie e cada local. A idade de Scorpaena porcus e Scorpaena notata variou entre 0 e 8 anos e 0 e 16 anos, respectivamente. O teste Kimura aplicado às curvas de crescimento de Bertalanffy indicaram que os indivíduos das duas espécies que habitam as estruturas artificiais tinham parâmetros de crescimento mais elevados do que

  14. Characteristics of C and O stable isotope in otolith of juvenile Coilia nasus from the Changjiang River Estuary%长江口刀鲚幼鱼耳石碳、氧同位素特征初报

    Institute of Scientific and Technical Information of China (English)

    姜涛; 刘洪波; 杨健

    2015-01-01

    为了解长江口刀鲚(Coilia nasus)耳石中碳、氧稳定同位素的特征及其可能反映出的生态学意义,作者利用稳定同位素质谱分析技术,首次对长江口刀鲚幼鱼的耳石进行碳、氧稳定同位素的初步研究。结果显示,δ13C和δ18O分别为–12.1±1.8(‰VPDB)和–7.9±1.2(‰VPDB),总体上δ13C波动较大,而δ18O波动较小。基于个体的δ13C和δ18O散点分布可将本研究中的刀鲚归为两个组,可能起源于长江中两个不同孵化场水域的群体,其中δ18O显示出两组刀鲚所经历环境积温上的差异,反映出两者起源水域温度环境的不同;而δ13C的差异说明两组刀鲚在饵料组成上的有所差异。%For better understanding of the characteristics of stable carbon (δ13C) and oxygen (δ18O) isotopes in the otolith ofCoilia nasusand the possible ecological significances, the analysis of otolith stable isotope ratios ofδ13C andδ18O was conducted using an isotope ratio mass spectrometry onC. nasus juveniles collected from the Chang-jiang River Estuary. The otolith revealedδ13C andδ18O values of –12.1±1.8(‰VPDB) and –7.9±1.2 (‰VPDB), respectively. Unlikeδ18O,δ13C generally varied in a relatively wide range. Two groups of the fish could be sepa-rated based on scattered distribution by otolithδ13C andδ18O values of allC. nasus individuals in the present study, suggesting possible different natal origins (i.e. spawning/nursery areas) in the Changjiang River. The different en-vironments with different water temperature and food organism composition might be experienced by the two groups ofC. nasus fish.

  15. 湘江鳡仔稚鱼个体和耳石生长发育研究%SOMATIC AND LAPILLUS OTOLITH ONTOGENETIC GROWTH AND DEVELOPMENT IN LARVAL AND JUVENILE ELOPICHTHYS BAMBUSA RICHARDSON IN THE XIANG RIVER

    Institute of Scientific and Technical Information of China (English)

    向建国; 向劲; 王星璐; 李钟杰; 谢松光

    2011-01-01

    E. Bambusa was collected in the Xiang River from June to July, 2008. Otolith analysis revealed that age of the specimens ranged from 4-25 days, and the back-calculated hatching dates were during May 27th to June 22nd. The mid-age of stage transition from preflexion to flexion was at the 6th day; from flexion to postflexion was at the 10th day; from postflexion to juvenile was at the 15.5th day. Piecewise regression revealed a knot in the growth functions of either body length or otolith radius, were both at the early postflexion stage (the 12nd-13rd day): the growth rate after the knot was 5 times and twice of that before the knot for body length and otolith radius respectively. The shape of lapillus was round in the preflexion stage; in the flexion stage, the anterior-posterior axis growth significantly exceeded along the dorsal-ventral axis, and the shape became oval; the otolith further elongated in the postflexion stage, and the peak of the posterior emerged to shape the whole lapillus pear; in the juvenile stage, the peak smoothed and the shape was mussel. Otolith shape and microstructural analyses can provide essential information revealing the critical events in the early life history of £. Bambusa.

  16. Otolith micro-structure analysis of rainbow trout alevins (Oncorhynchus mykiss under rearing conditions Análisis de la micro-estructura de otolitos en alevines de trucha arcoiris (Oncorhynchus mykiss en cautiverio

    Directory of Open Access Journals (Sweden)

    Guillermo Moyano

    2012-09-01

    Full Text Available Otolith microstructure (MO analysis was used to back-calculate growth patterns from hatching to the yolk-sac absorption in Rainbow trout alevins (Oncorhynchus mykiss, under experimental conditions, from winter to spring in Central-Chile. MO showed the following main features: (i occurrences of multiple primordia in the central region of otolith (MP; (ii several increments (22 ± 3 rings before a prominent hatch check surrounding MP and (iii existence of a very distinctive check associated to yolk-sac absorption. Further findings were the validation of daily periodicity of micro-increments and a significant linear relationship (P La micro-estructura de otolitos (MO fue utilizada para retro-calcular los patrones de crecimiento, desde la eclosión hasta la absorción del saco vitelino, en alevines de trucha arcoiris (Oncorhynchus mykiss, en la zona central de Chile. La MO mostró tres características principales: (i ocurrencia de múltiples primordios en la región central de los otolitos (MP, (ii formación de varios micro-incrementos antes de la eclosión (22 ± 3 micro-incrementos (iii y existencia de una marca distintiva correspondiente a la absorción del saco vitelino. Otros resultados fueron la validación de la periodicidad diaria de micro-incrementos y la existencia de una relación lineal significativa (P < 0,001; r2 = 0,91 entre la longitud máxima del otolito (LMO y la longitud total de los alevines (L T. La relación lineal L MO-L T validó el uso del método de intercepto biológico, para retro-calcular las tasas diarias de crecimiento (TDC. Las TDC mostraron una tendencia decreciente desde la eclosión hasta 6 días después de la absorción del saco vitelino (16 ± 1 días, las TDC variaron desde los 0,22 mm d-1 a los 0,34 mm d-1 (0,30 ± 0,037. La MO demostró ser una herramienta efectiva para el análisis retrospectivo de los patrones de crecimiento en alevins una vez absorbido su saco vitelino.

  17. Existence of anadromous Coilia nasus in Xinjiang River of Jiangxi Province as determined by otolith microchemistry%信江发现溯河洄游型刀鲚的实证研究

    Institute of Scientific and Technical Information of China (English)

    卢明杰; 姜涛; 刘洪波; 陈婷婷; 杨健

    2015-01-01

    利用电子探针微区分析技术,对2014年8月1日采自江西省余干县瑞洪镇信江(鄱阳湖水系五大河流之一)江段的刀鲚(Coilia nasus)的矢耳石进行了锶和钙的微化学分析研究。元素定量线分析表明,样品的锶钙比值(Sr/Ca×103)波动显著,不仅具有对应淡水生活的低值(Sr/Ca×103<3),而且出现了对应于海水生活的高值(3otoliths of C. nasus collected from the Ruihong section of the Xinjiang River (the most distant branch of Poyang Lake, ~1000 km from the Yangtze River estuary) near Yugan County in Jiangxi Province. Line transect results clearly showed a complex Sr/Ca ratio (i.e., Sr/Ca×103) pattern, including low-ratio freshwater habitat (Sr/Ca×103<3) and high-ratio seawater habitat (3

  18. The Treatment Effect of Otolith Particle Repositioning and Vestibular Rehabilitation Training on BPPV in Patients Over 65 Years%耳石颗粒复位和前庭康复训练对65岁以上良性阵发性位置性眩晕患者的疗效研究

    Institute of Scientific and Technical Information of China (English)

    李改丽; 汪丙昂; 徐贤华; 秦杨; 戎健; 白淑蓉; 邓涛; 李烨瑾

    2014-01-01

    目的:比较单独药物和耳石颗粒复位联合前庭康复训练联合药物对65岁以上良性阵发性位置性眩晕(BPPV)患者的临床疗效。方法136例患者随机分为药物组和联合治疗组。两组均给予药物治疗:敏使朗(12mg/d,3次/d)和金纳多(80mg/d,2次/d),口服,连续4周。联合组还给予耳石复位治疗和前庭康复训练(颈部保健操和手眼协调训练)。开始治疗后1个月和3个月门诊随访,每次随访评估其疗效。结果联合治疗组治疗周期明显缩短,临床缓解更早出现。治疗后两个随访时间点,联合治疗组的临床治愈率高于单纯药物治疗组。结论药物联合耳石手法复位和前庭康复训练治疗老年人BPPV见效快,疗效显著,复发少。%Objective To compare the clinical efficacy of drugs alone with otolith particle repositioning and vestibular re-habilitation training and drugs on BPPV patients over 65 years. Methods 136 patients were randomly divided into drugs group and combined treatment group. The two groups all were given drug( Betahistine,12 mg/d,tid and Ginaton,80 mg/d,bid) orally, consecutive 4W. The combined treatment group were also given canalith repositioning therapy and vestibular rehabilitation training (neck exercises and hand eye coordination training). All patients were followed up at 1m and 3m after the start of treatment and clinical efficacy was evaluated. Results The period was shortened obviously and clinical symptoms began to ease earlier in com-bined treatment group. In combined treatment group clinical cure rate was significantly higher than that of single drug treatment group at two follow-up time point. Conclusion The combination treatment for elderly BPPV patients of otolith particle reposition-ing and vestibular rehabilitation training and drugs takes effect more quickly,relieves more obviously,and relapses less.

  19. Otolith output - Project to study alternative life history types of fall Chinook based on otoliths

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The life-history complexity of Snake River fall Chinook salmon has hindered efforts to manage the ESU. In particular, the existence of an overwintering behavior in...

  20. 基于地标点几何形态测量法识别北部湾4种白姑鱼矢耳石形态%Using landmark-based geometric morphometrics analysis to identify sagittal otolith of four Pennahia fish species

    Institute of Scientific and Technical Information of China (English)

    侯刚; 刘丹丹; 冯波; 卢伙胜

    2013-01-01

    We investigated the identification in sagittal otoliths using landmark-based geometric morphometrics method among four sympatric species of the genus Pennahia: truncatetail white croaker P.anea (n=49), bighead white croaker P.macrocephalus (n=50), pawak croaker P. pawak (n=49) and white croaker P.argentata (n=29).The specimens were collected off Beibu Gulf from April 2010 to October 2010. Landmark coordinate values were extracted after otolith digitized by image processing and processed by relative warp principal component (RW), thin plate spline analysis and grad distortion. The 12 RW were then identified using discrimination analysis to differentiate the otoliths of four Pennahia species. The result indicated that, the 1st, 2nd and 3rd RW accounted for 46.57%, 25.39% and 10.02% of the total variation respectively, of which TypeⅠlandmarks 6 and 7, TypeⅡlandmarks 5 and 8 had important contributions, and could explain the most variation. The most morphological variation were displayed in neck, head width pole, and tail of tadpole-shaped sulcus. The gradual discrimination analysis and cross validation indicated that P.anea, P.macrocephalus and P. pawak got average exactitude distinguish ratios of 81.6%~100%, while P.argentata 58.6%, indicating that it contained a potential risk by using the morphology of tadpole-shaped impression owned by Sciaenidae to discriminate the four congeneric Pennahia species. It is necessary to notice this problem in the related otolith morphology research and application in feeding ecology.%利用2010年4月至2010年10月采自北部湾海域的49尾截尾白姑鱼(Pennahia anea)、50尾大头白姑鱼(P. macrocephalus)、49尾斑鳍白姑鱼(P. pawak )和29尾白姑鱼(P.argentata)矢耳石样本,运用基于地标点法的几何形态测量学方法研究了4种鱼类矢耳石形态识别问题。耳石经图像处理后提取地标点坐标值,进行相对扭曲主成分分析,通过判别分析来区分4种白姑鱼的耳石,

  1. Cardiovascular and Postural Control Interactions during Hypergravity: Effects on Cerebral Autoregulation in Males and Females

    Science.gov (United States)

    Goswami, Nandu; Blaber, Andrew; Bareille, Marie-Pierre; Beck, Arnaud; Avan, Paul; Bruner, Michelle; Hinghofer-Szalkay, Helmut

    2012-07-01

    Orthostatic intolerance remains a problem upon return to Earth from the microgravity environment of spaceflight. A variety of conditions including hypovolemia, cerebral vasoconstriction, cerebral or peripheral vascular disease, or cardiac arrhythmias may result in syncope if the person remains upright. Current research indicates that there is a greater dependence on visual and somatosensory information at the beginning of space flight with a decreased otolith gain during prolonged space flight (Herault et al., 2002). The goal of the research is to further our understanding of the fundamental adaptive homeostatic mechanisms involved in gravity related changes in cardiovascular and postural function. Cardiovascular, cerebrovascular, and postural sensory motor control systems in male and female participants before, during, and after exposure to graded levels of hyper-G were investigated. Hypotheses: 1) Activation of skeletal muscle pump will be directly related to the degree of orthostatic stress. 2) Simultaneous measurement of heart rate, blood pressure and postural sway will predict cardio-postural stability. Blood pressure and heart rate (means and variability), postural sway, center of pressure (COP), baroreflex function, calf blood flow, middle cerebral artery blood flow, non-invasive intracranial pressure measurements, and two-breath CO2 were measured. Results from the study will be used to provide an integrated insight into mechanisms of cardio-postural control and cerebral autoregulation, which are important aspects of human health in flights to Moon, Mars and distant planets.

  2. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  3. Clinical study of reducing the recurrence of Otolith disease by oral Betahistine and changing sleeping position%口服敏使朗及改变睡姿减少耳石症复发的临床研究

    Institute of Scientific and Technical Information of China (English)

    杨钱红; 姜玉龙; 陈林; 陆丽霞; 刘亮贤; 赵君

    2015-01-01

    Objective To study the value of oral Betahistine combined with changing sleeping position in re-ducing the recurrence of a single-ear canal benign paroxysmal positional vertigo (BPPV) with successful Epley reposi-tion.Methods The sleep situation was retrospectively studied in 117 elderly patients with BPPV of single-ear posterior semicircular canal,aged (62.1±8.2) in mean.The patients were required to determine the dominant side of sleeping posi-tion.All the patients received detailed medical history enquiry and physical examination of the nervous system,includ-ing posture and gait,eye movements,Dix-Hallpike test,and supine roll test.The patients were randomly divided into three groups:the control group (35 patients,treated by improved Epley reposition),treatment group A (40 patients,im-proved Epley reposition and changing sleeping position),treatment group B (42 patients,improved Epley reposition com-bined with Betahistine and changing sleeping position).Then,the recurrence rates of the three groups were analyzed.Results Among the 117 patients,the right side of the Dix-Hallpike test was positive for 74 patients,and the left Dix-Hallpike test was positive for 43 patients.When they sleep,61 patients used to right lateral position,and 32 patients used to left lateral position,with 21 patients of customary supine position.In the 117 patients with unilateral Dix-Hall-pike test positive,the affected ear and sleeping position were on the same side in 80 patients,including 54 on the right side and 26 on the left side.The affected ear and sleeping position were in the different sides in 16 patients,in which 10 of right lateral position showed positive results in left Dix-Hallpike test,and 6 of left lateral position showed positive re-sults in right Dix-Hallpike test.Among 21 patients of supine position,14 were positive in Dix-Hallpike test of the right side,and 7 were positive in Dix-Hallpike test of the left side.The affected ear showed a positive correlation with the

  4. Sensory Interactions for Head and Trunk Control in Space in Young and Older Adults During Normal and Narrow-Base Walking.

    Science.gov (United States)

    Zhang, Fang; Deshpande, Nandini

    2016-01-01

    Fifteen young (20-30 years old) and 15 older (>65 years old) healthy participants were recruited to investigate age-related differences in head and trunk control under suboptimal vestibular conditions (galvanic vestibular stimulation, or GVS) and vision conditions during normal and narrow-based walking. Head-roll velocity decreased in the blurred-vision condition and marginally increased with GVS in older but not in young participants. Head pitch increased, whereas head-roll velocity decreased in narrow-base walking. Trunk pitch, trunk-pitch velocity, and gait speed increased with GVS, whereas trunk-pitch velocity and gait speed decreased in narrow-base walking. Marginally increased head-roll velocity in the older participants possibly suggests decreased integrative ability of the central nervous system in elderly people. The changes in head control during narrow-base walking may be an attempt to simplify the interpretation of the vestibular signal and increase otolith sensitivity. The complexity of controlling the trunk in the mediolateral direction was suggested by different strategies used for trunk control in different conditions. PMID:25675141

  5. Antagonistic otolith-visual units in cat vestibular nuclei

    Science.gov (United States)

    Daunton, Nancy G.; Christensen, Carol A.

    1992-01-01

    The nature of neural coding of visual (Vis) and vestibular (Vst) information on translational motion in the region of the vestibular nuclei was investigated using extracellular single-unit recordings in alert adult cats. Responses were recorded and averaged over 60 cycles of stimulation in the vertical and horizontal planes, which included the Vst (movement of the animal in the dark), Vis (movement within lighted visual surround), and combined Vis and Vst (movement of the animal within the lighted stationary visual surround). Data are reported on responses to stimulations along the axis showing maximal sensitivity. A small number of units were identified that showed an antagonistic relationship between their Vis and Vst responses (since they were maximally excited by Vis and by Vst stimulations in the same direction). Results suggest that antagonistic units may belong to an infrequently encountered, but functionally distinct, class of neurons.

  6. Comparison of vertebrae and otoliths measured directly and from radiographs

    DEFF Research Database (Denmark)

    Pedersen, Jens

    1997-01-01

    from macerated fish. The present study shows that measurement of vertebrae from radiographs of intact fish is a reliable and quick method for estimating the relationship between vertebral length and fish length from a number of reference fish. The relationship between vertebrae size and fish length...... was established at least 10 times faster using radiographs than when direct measurements were used. (C) 1997 Elsevier Science B.V....

  7. Boom in boarfish abundance: insight from otolith analysis

    DEFF Research Database (Denmark)

    Coad, Julie Olivia; Hüssy, Karin

    2012-01-01

    The boarfish Capros aper is a pelagic shoaling species widely distributed along the Northeast Atlantic continental shelf. In recent years, this species has experienced a dramatic boom in abundance in the Bay of Biscay and Celtic Sea. This study aims at resolving the mechanisms responsible for thi...

  8. Bonefish-otoliths from the Anversian (Middle Miocene) of Antwerp

    NARCIS (Netherlands)

    Gaemers, P.A.M.

    1971-01-01

    31 species are listed from the Anversian in the neighbourhood of Antwerp (Belgium). Nine were previously known and one recorded species could not be found again. The relative abundances of the species are discussed, especially with reference to Trisopterus friedbergi and small species. The faunas fr

  9. Juvenile Salmonid Otolith Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  10. Controllable dose; Dosis controlable

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T.; Anaya M, R.A. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: jtar@nuclear.inin.mx

    2004-07-01

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  11. Birth Control

    Science.gov (United States)

    Birth control, also known as contraception, is designed to prevent pregnancy. Birth control methods may work in a number of different ... eggs that could be fertilized. Types include birth control pills, patches, shots, vaginal rings, and emergency contraceptive ...

  12. Neurofuzzy Control

    DEFF Research Database (Denmark)

    Jantzen, Jan

    1997-01-01

    These notes are for a course in fuzzy control and neural networks. By neural networks we more precisely mean neurofuzzy systems rather than pure neural network theory. The notes are an extension to the existing notes on fuzzy control (Jantzen, Fuzzy Control, 1994).......These notes are for a course in fuzzy control and neural networks. By neural networks we more precisely mean neurofuzzy systems rather than pure neural network theory. The notes are an extension to the existing notes on fuzzy control (Jantzen, Fuzzy Control, 1994)....

  13. Weight Control

    Science.gov (United States)

    ... obese. Achieving a healthy weight can help you control your cholesterol, blood pressure and blood sugar. It ... use more calories than you eat. A weight-control strategy might include Choosing low-fat, low-calorie ...

  14. Gaining control

    NARCIS (Netherlands)

    Enden, van der E.; Laan, van der R.

    2008-01-01

    The article reports on the efforts of companies to find a solution for tax risk management, tax accounting and being in control. In trying to find a solution, companies work towards an integrated tax control framework (TCF), a tax risk management and control environment embedded in the internal cont

  15. Controlling friction

    OpenAIRE

    Elmer, Franz-Josef

    1997-01-01

    Two different controlling methods are proposed to stabilize unstable continuous-sliding states of a dry-friction oscillator. Both methods are based on a delayed-feedback mechanism well-known for stabilizing periodic orbits in deterministic chaos. The feedback variable is the elastic deformation. The control parameter is either the sliding velocity or the normal force. We calculate analytically stability boundaries in the space of control parameter and delay time. Furthermore, we show that our...

  16. Nuclear control

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Wan Kee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    International cooperation in nuclear industries requires nuclear control as prerequisites. The concept of nuclear control is based on the Treaty on the Non-proliferation of Nuclear Weapon (NPT). The International Atomic Energy Agency (IAEA) plays central role in implementing nuclear control. Nuclear control consists of nuclear safeguards, physical protection, and export/import control. Each member state of NPT is subject to the IAEA`s safeguards by concluding safeguards agreements with the IAEA. IAEA recommends member states to implement physical protection on nuclear materials by `The Physical Protection of Nuclear Material` and `The Convention on the Physical Protection of Nuclear Material` of IAEA. Export/Import Control is to deter development of nuclear weapons by controlling international trade on nuclear materials, nuclear equipments and technology. Current status of domestic and foreign nuclear control implementation including recent induction of national inspection system in Korea is described and functions of recently set-up Technology Center for Nuclear Control (TCNC) under the Korea Atomic Energy Research Institute (KAERI) are also explained. 6 tabs., 11 refs. (Author).

  17. Associational control

    DEFF Research Database (Denmark)

    Hvid, Helge Søndergaard; Lund, Henrik Lambrecht; Grosen, Sidsel Lond;

    2010-01-01

    significance in the modern workplace which is simultaneously characterized by self-management and standardization. It is concluded that the concept of control remains important, but needs to evolve from its focus on the work of individuals to a focus on the associational aspects of work if it is to retain its......Over the last 30 years, the concept of control has had a central position in research into the psychological working environment. Control has been understood as individual autonomy and individual opportunities for development. This article examines whether the concept of control has the same key...

  18. Effects of fluctuating flows and a controlled flood on incubation success and early survival rates and growth of age-0 rainbow trout in a large regulated river

    Science.gov (United States)

    Korman, Josh; Kaplinski, Matthew; Melis, Theodore S.

    2011-01-01

    Hourly fluctuations in flow from Glen Canyon Dam were increased in an attempt to limit the population of nonnative rainbow trout Oncorhynchus mykiss in the Colorado River, Arizona, due to concerns about negative effects of nonnative trout on endangered native fishes. Controlled floods have also been conducted to enhance native fish habitat. We estimated that rainbow trout incubation mortality rates resulting from greater fluctuations in flow were 23-49% (2003 and 2004) compared with 5-11% under normal flow fluctuations (2006-2010). Effects of this mortality were apparent in redd excavations but were not seen in hatch date distributions or in the abundance of the age-0 population. Multiple lines of evidence indicated that a controlled flood in March 2008, which was intended to enhance native fish habitat, resulted in a large increase in early survival rates of age-0 rainbow trout. Age-0 abundance in July 2008 was over fourfold higher than expected given the number of viable eggs that produced these fish. A hatch date analysis indicated that early survival rates were much higher for cohorts that hatched about 1 month after the controlled flood (~April 15) relative to those that hatched before this date. The cohorts that were fertilized after the flood were not exposed to high flows and emerged into better-quality habitat with elevated food availability. Interannual differences in age-0 rainbow trout growth based on otolith microstructure supported this hypothesis. It is likely that strong compensation in survival rates shortly after emergence mitigated the impact of incubation losses caused by increases in flow fluctuations. Control of nonnative fish populations will be most effective when additional mortality is applied to older life stages after the majority of density-dependent mortality has occurred. Our study highlights the need to rigorously assess instream flow decisions through the evaluation of population-level responses.

  19. Effects of Artificial Gravity and Bed Rest on Spatial Orientation and Balance Control

    Science.gov (United States)

    Paloski, William H.; Moore, S. T.; Feiveson, A. H.; Taylor, L. C.

    2007-01-01

    While the vestibular system should be well-adapted to bed rest (a condition it experiences approximately 8/24 hrs each day), questions remain regarding the degree to which repeated exposures to the unusual gravito-inertial force environment of a short-radius centrifuge might affect central processing of vestibular information used in spatial orientation and balance control. Should these functions be impaired by intermittent AG, its feasibility as a counter-measure would be diminished. We, therefore, examined the effects of AG on spatial orientation and balance control in 15 male volunteers before and after 21 days of 6 HDT bed rest (BR). Eight of the subjects were treated with daily 1hr AG exposures (2.5g at the feet; 1.0g at the heart) aboard a short radius (3m) centrifuge, while the other seven served as controls (C). Spatial orientation was assessed by measures of ocular counter-rolling (OCR; rotation of the eye about the line of sight, an otolith-mediated reflex) and subjective visual vertical (SVV; perception of the spatial upright). Both OCR and SVV measurements were made with the subject upright, lying on their left sides, and lying on their right sides. OCR was measured from binocular eye orientation recordings made while the subjects fixated for 10s on a point target directly in front of the face at a distance of 1 m. SVV was assessed by asking subjects (in the dark) to adjust to upright (using a handheld controller) the orientation of a luminous bar randomly perturbed (15) to either side of the vertical meridian. Balance control performance was assessed using a computerized dynamic posturography (CDP) protocol similar to that currently required for all returning crew members. During each session, the subjects completed a combination of trials of sensory organization test (SOT) 2 (eyes closed, fixed platform) and SOT 5 (eyes closed, sway-referenced platform) with and without static and dynamic pitch plane head movements (plus or minus 20 deg., dynamic

  20. Taking Control

    Centers for Disease Control (CDC) Podcasts

    2007-11-01

    This podcast gives action steps and reasons to control diabetes.  Created: 11/1/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health.   Date Released: 11/2/2007.

  1. optimal control

    Directory of Open Access Journals (Sweden)

    L. I. Rozonoer

    1999-01-01

    Full Text Available Necessary and sufficient conditions for existence of optimal control for all initial data are proved for LQ-optimization problem. If these conditions are fulfilled, necessary and sufficient conditions of optimality are formulated. Basing on the results, some general hypotheses on optimal control in terms of Pontryagin's maximum condition and Bellman's equation are proposed.

  2. Detonation control

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Jonathan L.; Seitz, Gerald J.; Bronisz, Lawrence E.

    2016-10-25

    Detonation control modules and detonation control circuits are provided herein. A trigger input signal can cause a detonation control module to trigger a detonator. A detonation control module can include a timing circuit, a light-producing diode such as a laser diode, an optically triggered diode, and a high-voltage capacitor. The trigger input signal can activate the timing circuit. The timing circuit can control activation of the light-producing diode. Activation of the light-producing diode illuminates and activates the optically triggered diode. The optically triggered diode can be coupled between the high-voltage capacitor and the detonator. Activation of the optically triggered diode causes a power pulse to be released from the high-voltage capacitor that triggers the detonator.

  3. Controlling chimeras

    Science.gov (United States)

    Bick, Christian; Martens, Erik A.

    2015-03-01

    Coupled phase oscillators model a variety of dynamical phenomena in nature and technological applications. Non-local coupling gives rise to chimera states which are characterized by a distinct part of phase-synchronized oscillators while the remaining ones move incoherently. Here, we apply the idea of control to chimera states: using gradient dynamics to exploit drift of a chimera, it will attain any desired target position. Through control, chimera states become functionally relevant; for example, the controlled position of localized synchrony may encode information and perform computations. Since functional aspects are crucial in (neuro-)biology and technology, the localized synchronization of a chimera state becomes accessible to develop novel applications. Based on gradient dynamics, our control strategy applies to any suitable observable and can be generalized to arbitrary dimensions. Thus, the applicability of chimera control goes beyond chimera states in non-locally coupled systems.

  4. Controller for thermostatically controlled loads

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Ning; Zhang, Yu; Du, Pengwei; Makarov, Yuri V.

    2016-06-07

    A system and method of controlling aggregated thermostatically controlled appliances (TCAs) for demand response is disclosed. A targeted load profile is formulated and a forecasted load profile is generated. The TCAs within an "on" or "off" control group are prioritized based on their operating temperatures. The "on" or "off" status of the TCAs is determined. Command signals are sent to turn on or turn off the TCAs.

  5. Losing control

    DEFF Research Database (Denmark)

    Leppink, Eric; Odlaug, Brian Lawrence; Lust, Katherine;

    2014-01-01

    OBJECTIVE: Assaultive behaviors are common among young people and have been associated with a range of other unhealthy, impulsive behaviors such as substance use and problem gambling. This study sought to determine the predictive ability of single assaultive incidents for impulse control disorders...... with respondents without lifetime assaultive behavior, those with a history of assaultive or destructive behavior reported more depressive symptoms, more stress, and higher rates of a range of impulse control disorders (intermittent explosive disorder, compulsive sexual behavior, compulsive buying, and skin...... picking disorder). CONCLUSIONS: Assaultive behavior appears fairly common among college students and is associated with symptoms of depression and impulse control disorders. Significant distress and diminished behavioral control suggest that assaultive behaviors may often be associated with significant...

  6. CONTROL ROD

    Science.gov (United States)

    Zinn, W.H.; Ross, H.V.

    1958-11-18

    A control rod is described for a nuclear reactor. In certaln reactor designs it becomes desirable to use a control rod having great width but relatively llttle thickness. This patent is addressed to such a need. The neutron absorbing material is inserted in a triangular tube, leaving volds between the circular insert and the corners of the triangular tube. The material is positioned within the tube by the use of dummy spacers to achleve the desired absorption pattern, then the ends of the tubes are sealed with suitable plugs. The tubes may be welded or soldered together to form two flat surfaces of any desired width, and covered with sheetmetal to protect the tubes from damage. This design provides a control member that will not distort under the action of outside forces or be ruptured by gases generated within the jacketed control member.

  7. Controlling chimeras

    OpenAIRE

    Bick, Christian; Martens, Erik Andreas

    2015-01-01

    Coupled phase oscillators model a variety of dynamical phenomena in nature and technological applications. Non-local coupling gives rise to chimera states which are characterized by a distinct part of phase-synchronized oscillators while the remaining ones move incoherently. Here, we apply the idea of control to chimera states: using gradient dynamics to exploit drift of a chimera, it will attain any desired target position. Through control, chimera states become functionally relevant; for ex...

  8. IT controlling

    OpenAIRE

    Stehlík, Libor

    2010-01-01

    The main aim of this thesis is to acquaint the reader with the possibilities of economic management of enterprise information technology field by using tools provided by financial controlling and to propose an appropriate metrics for performance measurement of this area. The thesis is logically divided into three comprehensive parts. Firstly, the reader is acquainted with the historical evolution and general principles of controlling management approach, which is then applied to IT field. Alo...

  9. Spatial Cognition, Body Representation and Affective Processes: The Role of Vestibular Information beyond Ocular Reflexes and Control of Posture

    Directory of Open Access Journals (Sweden)

    Fred W Mast

    2014-05-01

    Full Text Available A growing number of studies in humans demonstrate the involvement of vestibular information in tasks that are seemingly remote from well-known functions such as space constancy or postural control. In this review article we point out three emerging streams of research highlighting the importance of vestibular input: 1 Spatial Cognition: Modulation of vestibular signals can induce specific changes in spatial cognitive tasks like mental imagery and the processing of numbers. This has been shown in studies manipulating body orientation (changing the input from the otoliths, body rotation (changing the input from the semicircular canals, in clinical findings with vestibular patients, and in studies carried out in microgravity. There is also an effect in the reverse direction; top-down processes can affect perception of vestibular stimuli. 2 Body Representation: Numerous studies demonstrate that vestibular stimulation changes the representation of body parts, and sensitivity to tactile input or pain. Thus, the vestibular system plays an integral role in multisensory coordination of body representation. 3 Affective Processes and Disorders: Studies in psychiatric patients and patients with a vestibular disorder report a high comorbidity of vestibular dysfunctions and psychiatric symptoms. Recent studies investigated the beneficial effect of vestibular stimulation on psychiatric disorders, and how vestibular input can change mood and affect. These three emerging streams of research in vestibular science are – at least in part – associated with different neuronal core mechanisms. Spatial transformations draw on parietal areas, body representation is associated with somatosensory areas, and affective processes involve insular and cingulate cortices, all of which receive vestibular input. Even though a wide range of different vestibular cortical projection areas has been ascertained, their functionality still is scarcely understood.

  10. Management control or control management?

    Directory of Open Access Journals (Sweden)

    José Carlos Dextre Flores

    2012-12-01

    Full Text Available The attempt to answer the title of this article frames the analysis of the concept of control as a key role of the management, which any entity applies in pursuit of its institutional fulfillment. The control intervention in the development of the activities carried out by organizations to achieve the planned objectives of economic, social or political order constitutes its core business, as it seeks to ensure that those activities—operations and processes—are conducted safely, continuous and reliable. This applies both to those who constitute the organization and those who have expectations of management efficiency and the effectiveness of the expected results. In this paper, on the one hand, we propose to revise the control concept and its application in the exercise of monitoring the management performance; on the other hand, we seek to show how control should be managed to achieve efficient and effective results.

  11. Controlling pollution by controlling combustion

    Energy Technology Data Exchange (ETDEWEB)

    Orrin, John (South Bank Univ., London (United Kingdom))

    1994-05-04

    Modern control theory is now being used to reduce pollution from fossil fuel combustion. Powerful microprocessors using digital control algorithms are now used to make combustion systems, such as industrial furnaces and car engines, operate with optimal performance. These systems operate to achieve a balance between lean fuel burning with the reduced pollution produced, but more engine noise and vibration, and an air/fuel mixture that produces good engine performance but worse pollution. (UK)

  12. Controlled teleportation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this article,we review the recent development of controlled teleportation which can be used for sharing quantum information and has important applications in remote quantum computation.We introduce the principles of a couple of controlled teleportation schemes with maximally entangled quantum channels and those with pure entangled quantum channels (non-maximally entangled states).The schemes based on maximally entangled states have the advantage of having maximal efficiency although there are differences in their implementations in experiment.In the controlled teleportation schemes using non-maximally entangled states as the quantum channels,the receiver can reconstruct the originally unknown state by adding an auxiliary particle and performing a unitary evolution.No matter what the unknown state is (a single qubit state or an m-qudit state),the auxiliary particle required is only a two-level quantum system.

  13. Optimal Control

    CERN Document Server

    Vinter, Richard

    2010-01-01

    "Each chapter contains a well-written introduction and notes. They include the author's deep insights on the subject matter and provide historical comments and guidance to related literature. This book may well become an important milestone in the literature of optimal control." --Mathematical Reviews "Thanks to a great effort to be self-contained, [this book] renders accessibly the subject to a wide audience. Therefore, it is recommended to all researchers and professionals interested in Optimal Control and its engineering and economic applications. It can serve as an excellent

  14. Controlling turbulence

    Science.gov (United States)

    Kühnen, Jakob; Hof, Björn

    2015-11-01

    We show that a simple modification of the velocity profile in a pipe can lead to a complete collapse of turbulence and the flow fully relaminarises. The annihilation of turbulence is achieved by a steady manipulation of the streamwise velocity component alone, greatly reducing control efforts. Several different control techniques are presented: one with a local modification of the flow profile by means of a stationary obstacle, one employing a nozzle injecting fluid through a small gap at the pipe wall and one with a moving wall, where a part of the pipe is shifted in the streamwise direction. All control techniques act on the flow such that the streamwise velocity profile becomes more flat and turbulence gradually grows faint and disappears. In a smooth straight pipe the flow remains laminar downstream of the control. Hence a reduction in skin friction by a factor of 8 and more can be accomplished. Stereoscopic PIV-measurements and movies of the development of the flow during relaminarisation are presented.

  15. CONTROLLING DIFFUSION

    NARCIS (Netherlands)

    WESSELINGH, JA

    1993-01-01

    In this paper I first briefly look at diffusion in several controlled release devices. I have found that these exploit complicated diffusional mechanisms. These cannot be understood using the conventional description of diffusion. So, a general theory of multicomponent diffusion which can describe t

  16. Internal Controls

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Managing risk is essential for positioning a company for growth in the current business environment.Yet as companies around the world clamber to inplement integrated risk controls in light of corlporate meltdowns and terrorist concems,many firms fail to pull the weeds out of their own backyard in China before trying to harvest the profitable crops!

  17. Controllable dose

    International Nuclear Information System (INIS)

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  18. Control presupuestario

    OpenAIRE

    Pérez-Bonaventura, Marc

    2015-01-01

    Los presupuestos son una herramienta de control muy útil en las empresas. Este recurso didáctico se ha creado con la intención de explicar el presupuesto previsto, el presupuesto real, el presupuesto flexible, el presupuesto revisado y sus desviaciones de una forma simple y didáctica. Este documento muestra a nivel teórico, esquemático y con ejemplos numéricos la formación de los diferentes presupuestos y las desviaciones existentes entre ellos.

  19. Heliostat control

    Science.gov (United States)

    Kaehler, James A.

    1984-01-01

    An improvement in a system and method of controlling heliostat in which the heliostat is operable in azimuth and elevation by respective stepper motors and including the respective steps or means for calculating the position for the heliostat to be at a commanded position, determining the number of steps in azimuth and elevation for each respective motor to get to the commanded position and energizing both the azimuth and elevation stepper motors to run in parallel until predetermined number of steps away from the closest commanded position in azimuth and elevation so that the closest position has been achieved, and thereafter energizing only the remaining motor to bring it to its commanded position. In this way, the heliostat can be started from a stowed position in the morning and operated by a computer means to its commanded position and kept correctly oriented throughout the day using only the time of the day without requiring the usual sensors and feedback apparatus. A computer, or microprocessor, can then control a plurality of many heliostats easily and efficiently throughout the day.

  20. Control Cognitivo

    Directory of Open Access Journals (Sweden)

    María Pavón

    2013-12-01

    Full Text Available Las respuestas obtenidas permitieron dilucidar tanto las diversas situaciones en que las personas intentan controlar cognitivamente sus emociones, así como las estrategias que utilizan para lograr dicho fin. A partir de un análisis de contenido centrado en las respuestas, surgieron dos sistemas clasificatorios: el primero hace referencia a los motivos que hacen que una persona controle cognitivamente sus emociones y contiene las siguientes dimensiones: según valencia de emoción, intensidad de la emoción, según tipo de relación, según situación o contexto y según grado de simetría. El segundo sistema clasificatorio mencionado, refiere a los mecanismos de control que las personas entrevistadas utilizan. Esta clasificación consta de 4 dimensiones: distracción, evitación reflexión y supresión emocional. Los resultados indican tanto similitudes como diferencias entre los grupos. Respecto a estas últimas, las más relevantes se encontraron entre el grupo de personas de 20 a 30 años y las de 80 a 90. Se ha encontrado que con el correr de los años, las personas empiezan a poner énfasis en el valor de la experiencia para afrontar y controlar las diferentes situaciones.

  1. Control rod

    International Nuclear Information System (INIS)

    Purpose: To enable semi-permanent and safety use of a control rod in a water cooled type reactor operated under high temperature and high pressure conditions by using a blade in which hafnium materials at a nuclear reactor quality are covered with stainless steels or zirconium alloys. Constitution: A plate-like hafnium material is surrounded with a thin plate of stainless steels or zirconium alloys under vacuum and the joint portions of the thin plate is subjected to seam welding. Then a blade is prepared by welding the remaining joining portions at both ends in a conventional manner. The welding method usable herein includes electron beam welding, laser welding and the like. If it is required to increase the close bondability between the halfnium plate and the thin plate, the blade thus obtained is subjected as it is to extrusion fabrication thereby obtain a desired increased bondability. (Kawakami, Y.)

  2. Roof control

    Energy Technology Data Exchange (ETDEWEB)

    Woof, M.

    1999-10-01

    Joy has produced a roof support with a new shape and which offers both high productivity and good operator safety. It features high levels of ambient lighting, low working noise levels, a simple control layout, a wide operating platform, and good all-round visibility. The first underground tests with the trial machine at Capcoal's Central Colliery in Australia set production records, with 304 of the 1.8 m bolts in 3 hours 45 minutes. This was broken by Arch Coal's Sufco mine in Utah, USA when a unit installed 304 of 1.8 m fully encapsulated bolts in 3 hr 20 mins. The article gives detail on design features. 1 photo.

  3. COPD - control drugs

    Science.gov (United States)

    Chronic obstructive pulmonary disease - control drugs; Bronchodilators - COPD - control drugs; Beta agonist inhaler - COPD - control drugs; Anticholinergic inhaler - COPD - control drugs; Long-acting inhaler - COPD - ...

  4. Custom controls

    Science.gov (United States)

    Butell, Bart

    1996-02-01

    Microsoft's Visual Basic (VB) and Borland's Delphi provide an extremely robust programming environment for delivering multimedia solutions for interactive kiosks, games and titles. Their object oriented use of standard and custom controls enable a user to build extremely powerful applications. A multipurpose, database enabled programming environment that can provide an event driven interface functions as a multimedia kernel. This kernel can provide a variety of authoring solutions (e.g. a timeline based model similar to Macromedia Director or a node authoring model similar to Icon Author). At the heart of the kernel is a set of low level multimedia components providing object oriented interfaces for graphics, audio, video and imaging. Data preparation tools (e.g., layout, palette and Sprite Editors) could be built to manage the media database. The flexible interface for VB allows the construction of an infinite number of user models. The proliferation of these models within a popular, easy to use environment will allow the vast developer segment of 'producer' types to bring their ideas to the market. This is the key to building exciting, content rich multimedia solutions. Microsoft's VB and Borland's Delphi environments combined with multimedia components enable these possibilities.

  5. Power Controller

    Science.gov (United States)

    1982-01-01

    The device called the Power Factor Controller (PFC) offers exceptional energy conservation potential by virtue of its ability to sense shifts in the relationship between voltage and current flow, and to match them with the motor's need. Originating from the solar heating/cooling program, the PFC senses a light load, it cuts the voltage level to the minimum needed which in turn reduces current flow and heat loss. Laboratory tests showed that the PFC could reduce power used by six to eight percent under normal motor loads, and as much as 65 percent when the motor was idling. Over 150 companies have been granted NASA licenses for commercial use of this technology. One system that utilizes this technology is the Vectrol Energy System, (VES) produced by Vectrol, Inc. a subsidiary of Westinghouse. The VES is being used at Woodward & Lothrop, on their escalators. Energy use is regulated according to how many people are on the escalator at any time. It is estimated that the energy savings are between 30 to 40 percent.

  6. Relationship between fuzzy controllers and PID controllers

    Institute of Scientific and Technical Information of China (English)

    李洪兴

    1999-01-01

    The internal relations between fuzzy controllers and PID controllers are revealed. First, it is pointed out that a fuzzy controller with one input and one output is just a piecewise P controller. Then it is proved that a fuzzy controller with two inputs and one output is just a piecewise PD (or I) controller with interaction between P and D (or PI). At last, the conclusion that a fuzzy controller with three inputs and one output is just a piecewise PID controller with interaction among P, I and D is given. Moreover, a kind of difference scheme of fuzzy controllers is designed.

  7. Intelligent Controller for Networked DC Motor Control

    OpenAIRE

    B. Sharmila; N. Devarajan

    2010-01-01

    This paper focuses on the feasibility of Neural Network controller for Networked Control Systems. The Intelligent Controllers has been developed for controlling the speed of the Networked DC Motor by exploiting the features of Neural Networks and Fuzzy Logic Controllers. The major challenges in Networked Control Systems are the network induced delays and data packet losses in the closed loop. These challenges degrade the performance and destabilize the systems. The aim of the proposed Neural ...

  8. 1999 American control conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The technical program reflects the rapid growth and strong interest in the field of control systems engineering. Leaders in the field provide a good balance between control theory and a broad spectrum of practical applications. Topics covered include: nonlinear control using backstepping; adaptive control; vibration control via command shaping; observer based fault detection; control applications; advances in passivity-based control methods; stability and time-delay systems; identification; intelligent systems; robust control; advances in control education.

  9. Incoherent control of locally controllable quantum systems

    International Nuclear Information System (INIS)

    An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective measurement of the amplified state, and (3) final optimization by a unitary controlled transformation. The first step increases the amplitudes of some desired eigenstates and the corresponding probability of observing these eigenstates, the second step projects, with high probability, the amplified state into a desired eigenstate, and the last step steers this eigenstate into the target state. Within this scheme, two control algorithms are presented for two classes of quantum systems. As an example, the incoherent control scheme is applied to the control of a hydrogen atom by an external field. The results support the suggestion that projective measurements can serve as an effective control and local controllability information can be used to design control laws for quantum systems. Thus, this scheme establishes a subtle connection between control design and controllability analysis of quantum systems and provides an effective engineering approach in controlling quantum systems with partial controllability information.

  10. Contact Control, Version 1

    Energy Technology Data Exchange (ETDEWEB)

    2016-07-21

    The contact control code is a generalized force control scheme meant to interface with a robotic arm being controlled using the Robot Operating System (ROS). The code allows the user to specify a control scheme for each control dimension in a way that many different control task controllers could be built from the same generalized controller. The input to the code includes maximum velocity, maximum force, maximum displacement, and a control law assigned to each direction and the output is a 6 degree of freedom velocity command that is sent to the robot controller.

  11. Are estimated control charts in control?

    NARCIS (Netherlands)

    Albers, W.; Kallenberg, W.C.M.

    2001-01-01

    Standard control chart practice assumes normality and uses estimated parameters. Because of the extreme quantiles involved, large relative errors result. Here simple corrections are derived to bring such estimated charts under control. As a criterion, suitable exceedance probabilities are used.

  12. Cognitive Control in the Controllable Connectome

    OpenAIRE

    Medaglia, John D.; Gu, Shi; Pasqualetti, Fabio; Ashare, Rebecca L.; Lerman, Caryn; Kable, Joseph; Bassett, Danielle S

    2016-01-01

    Cognition is supported by neurophysiological processes that occur both in local anatomical neighborhoods and in distributed large-scale circuits. Recent evidence from network control theory suggests that white matter pathways linking large-scale brain regions provide a critical substrate constraining the ability of single areas to affect control on those processes. Yet, no direct evidence exists for a relationship between brain network controllability and cognitive control performance. Here, ...

  13. Development of the gravity-sensing organs in the Japanese red-bellied newt, Cynops pyrrhogaster

    Science.gov (United States)

    Wiederhold, Michael L.; Yamashita, Masamichi; Asashima, Makoto

    1992-01-01

    Pre-mated adult female newts and fertilized eggs will be flown on the International Microgravity Laboratory-2 flight, schedule for 1994. One objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. These organs contain sensory hair cells covered by a layer of dense stones (otoliths). Gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. If the production of the otoliths is regulated to reach an optimal weight, their development would be abnormal in microgravity. Ground-based control experiments are reported describing the developmental sequence in which the otoliths and their associated sensory epithelium appear and increase in size. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos at stages 31 through 40 demonstrate the first appearance, relative position and growth of the otoliths. In adult newts, the otoconia in the utricle appear similar to mammalian otoconia, which are composed of calcite. The newt saccular otoconia are at least 99% aragonite, as is found in most aquatic species. Reports of experiments in which fertilized frog eggs were flown on a Russian Cosmos mission conclude that the utricular otolith is increased in volume, whereas the saccular otolith maintains normal size, suggesting that at least the utricular weight might be regulated.

  14. Formation of otoconia in the Japanese red-bellied newt, Cynops pyrrhogaster

    Science.gov (United States)

    Wiederhold, M. L.; Yamashita, M.; Larsen, K.; Asashima, M.

    1994-08-01

    Pre-mated adult female newts and fertilized eggs will be flown on the International Microgravity Laboratory-2 flight, in 1994. One objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. These organs contain sensory hair cells covered by a layer of dense stones (otoconia). Gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. If the production of the otoliths is regulated to reach an optimal weight, their development might be abnormal in microgravity. Ground-based control experiments are reported describing the developmental sequence in which both the otoliths and their associated sensory epithelium and the semicircular canals appear and develop. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos at stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. Reports of experiments in which fertilized frog eggs were flown on a Russian Cosmos mission conclude that the utricular otolith is increased in volume, whereas the saccular otolith maintains normal size, suggesting that at least in the utricle, the weight of the otolith might be regulated.

  15. PID control with robust disturbance feedback control

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Vinther, Kasper; Andersen, Palle;

    2015-01-01

    Disturbance Feedback Control (DFC) is a technique, originally proposed by Fuji Electric, for augmenting existing control systems with an extra feedback for attenuation of disturbances and model errors. In this work, we analyze the robustness and performance of a PID-based control system with DFC...... and performance (if such gains exist). Finally, two different simulation case studies are evaluated and compared. Our numerical studies indicate that better performance can be achieved with the proposed method compared with a conservatively tuned PID controller and comparable performance can be achieved when...... compared with an H-infinity controller....

  16. A Digital Controller for Active Aeroelastic Controls

    OpenAIRE

    Ueda, Tetsuhiko; MUROTA, Katsuichi; 上田, 哲彦; 室田, 勝一

    1989-01-01

    A high-speed digital controller for aeroelastic controls was designed and made. The purpose was to minimize adverse phase lag which is inevitably produced by the CPU time of digital processing. The delay deteriorates control performances on rather rapid phenomena like aircraft flutter. With fix-point operation the controller realized 417 microseconds of throughput time including the A/D and D/A conversion. This corresponds to a high sampling rate of 2.4kHz. The controller furnishes two channe...

  17. INTELLIGENT CONTROL USING ADAPTIVE PID CONTROLLER

    Directory of Open Access Journals (Sweden)

    DR. P VIJAYAKUMAR

    2014-02-01

    Full Text Available In this paper an adaptive stable PID controller is briefly explained and validated by simulations and experimentation. The adaptive PID controller employs almost strict positive realness (ASPR to ensure stability of the system. The design involves a parallel feedforward compensator (PFC which guarantees the ASPRness of the controlled system. After a disturbance the dynamical system is assumed to be in one of a finite number of configurations, corresponding to each of which exist a stabilizing controller. The effectiveness of the method is tested and compared using simulations and experiments on a level control experimental setup.

  18. GCFR plant control system

    International Nuclear Information System (INIS)

    A plant control system is being designed for a gas-cooled fast breeder reactor (GCFR) demonstration plant. Control analysis is being performed as an integral part of the plant design process to ensure that control requirements are satisfied as the plant design evolves. The load control portion of the plant control system provides stable automatic (closed-loop) control of the plant over the 25% to 100% load range. Simulation results are presented to demonstrate load control system performance. The results show that the plant is controllable at full load with the control system structure selected, but gain scheduling is required to achieve desired performance over the load range

  19. Substructural controller synthesis

    Science.gov (United States)

    Su, Tzu-Jeng; Craig, Roy R., Jr.

    1989-01-01

    A decentralized design procedure which combines substructural synthesis, model reduction, decentralized controller design, subcontroller synthesis, and controller reduction is proposed for the control design of flexible structures. The structure to be controlled is decomposed into several substructures, which are modeled by component mode synthesis methods. For each substructure, a subcontroller is designed by using the linear quadratic optimal control theory. Then, a controller synthesis scheme called Substructural Controller Synthesis (SCS) is used to assemble the subcontrollers into a system controller, which is to be used to control the whole structure.

  20. Motion control report

    CERN Document Server

    2013-01-01

    Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List

  1. Structural Pest Control.

    Science.gov (United States)

    Kahn, M. S.; Hoffman, W. M.

    This manual is designed for those who seek certification as pesticide applicators for industrial, institutional, structural, and health-related pest control. It is divided into six sections covering general pest control, wood-destroying organisms, bird control, fumigation, rodent control, and industrial weed control. The manual gives information…

  2. Fuzzy Supervisory Control

    DEFF Research Database (Denmark)

    Jantzen, Jan

    1998-01-01

    Control problems in the process industry are dominated by non-linear and time-varying behaviour, many inner loops, and much interaction between the control loops. Fuzzy controllers have in some cases nevertheless mimicked the control actions of a human operator. For high level control and...

  3. Adaptive Extremum Control and Wind Turbine Control

    DEFF Research Database (Denmark)

    Ma, Xin

    1997-01-01

    This thesis is divided into two parts, i.e., adaptive extremum control and modelling and control of a wind turbine. The rst part of the thesis deals with the design of adaptive extremum controllers for some processes which have the behaviour that process should have as high e ciency as possible...... in parameters, and thus directly lends itself to parameter estimation and adaptive control. The extremum control law is derived based on static optimization of a performance function. For a process with nonlinearity at output the intermediate signal between the linear part and nonlinear part plays an important...... role. If it can be emphasis on control design. The models have beenvalidated by experimental data obtained from an existing wind turbine. The e ective wind speed experienced by the rotor of a wind turbine, which is often required by some control methods, is estimated by using a wind turbine as a wind...

  4. Modular thyristor controlled series capacitor control system

    Energy Technology Data Exchange (ETDEWEB)

    Clark, K.; Larsen, E.V.; Wegner, C.A.; Piwko, R.J.

    1995-06-13

    A modular thyristor controlled series capacitor (TCSC) system, including a method and apparatus, uses phase controlled firing based on monitored capacitor voltage and line current. For vernier operation, the TCSC system predicts an upcoming firing angle for switching a thyristor controlled commutating circuit to bypass line current around a series capacitor. Each bypass current pulse changes the capacitor voltage proportionally to the integrated value of the current pulse. The TCSC system promptly responds to an offset command from a higher-level controller to control bypass thyristor duty to minimize thyristor damage, and to prevent capacitor voltage drift during line current disturbances. In a multi-module TCSC system, the higher level controller accommodates competing objectives of various system demands, including minimizing losses in scheduling control, stabilizing transients, damping subsynchronous resonance (SSR) oscillations, damping direct current (DC) offset, and damping power-swings. 67 figs.

  5. Controlling chaos using an exponential control

    CERN Document Server

    Gadre, S D; Gadre, Sangeeta D; Varma, V S

    1995-01-01

    We demonstrate that chaos can be controlled using a multiplicative exponential feedback control. All three types of unstable orbits - unstable fixed points, limit cycles and chaotic trajectories can be stabilized using this control. The control is effective both for maps and flows. The control is significant, particularly for systems with several degrees of freedom, as knowledge of only one variable on the desired unstable orbit is sufficient to settle the system on to that orbit. We find, that in all the cases studied, the transient time is a decreasing function of the stiffness of control. But increasing the stiffness beyond an optimum value can increase the transient time. The control can also be used to create suitable new stable attractors in a map, which did not exist in the original system.

  6. Robust H∞ control for networked control systems

    Institute of Scientific and Technical Information of China (English)

    Ma Weiguo; Shao Cheng

    2008-01-01

    The robust H∞ control for networked control systems with both stochastic network-induced delay and data packet dropout is studied.When data are transmitted over network,the stochastic data packet dropout process can be described by a two-state Markov chain.The networked control systems with stochastic network-induced delay and data packet dropout are modeled as a discrete time Markov jump linear system with two operation modes.The sufficient condition of robust H∞ control for networked control systems stabilized by state feedback controller is presented in terms of linear matrix inequality.The state feedback controller can be constructed via the solution of a set of linear matrix inequalities.An example is given to verify the effectiveness of the method proposed.

  7. Control Measure Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EPA Control Measure Dataset is a collection of documents describing air pollution control available to regulated facilities for the control and abatement of air...

  8. Nominal model predictive control

    OpenAIRE

    Grüne, Lars

    2013-01-01

    5 p., to appear in Encyclopedia of Systems and Control, Tariq Samad, John Baillieul (eds.); International audience; Model Predictive Control is a controller design method which synthesizes a sampled data feedback controller from the iterative solution of open loop optimal control problems.We describe the basic functionality of MPC controllers, their properties regarding feasibility, stability and performance and the assumptions needed in order to rigorously ensure these properties in a nomina...

  9. Test Control Center (TCC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Test Control Center (TCC) provides a consolidated facility for planning, coordinating, controlling, monitoring, and analyzing distributed test events. ,The TCC...

  10. Unfalsified control based on the ? controller parameterisation

    Science.gov (United States)

    Sánchez-Peña, R. S.; Colmegna, P.; Bianchi, F.

    2015-11-01

    This paper presents an implementation of the unfalsified control (UC) method using the Riccati-based parameterisation of ? controllers. The method provides an infinite controller set to (un)falsify the real-time data streams seeking for the best performance. Different sets may be designed to increase the degrees of freedom of the set of controller candidates to perform UC. In general, a set of m central controllers could be designed, each one seeking different objectives and all with their own parameterisation as a function of a stable and bounded transfer matrix. For example, one controller parameterisation could be designed to solve the robust stability of a model set which covers the physical system, therefore guaranteeing feasibility. The implementation requires the online optimisation of either quadratic fractional or quadratic problems, depending on the selection of the cost function. A multi-input, multi-output (MIMO) time-varying model of a permanent magnet synchronous generator illustrates the use of this technique.

  11. INTELLIGENT CONTROL USING ADAPTIVE PID CONTROLLER

    OpenAIRE

    Dr. P. Vijayakumar; UNNIKRISHNAN P C

    2014-01-01

    In this paper an adaptive stable PID controller is briefly explained and validated by simulations and experimentation. The adaptive PID controller employs almost strict positive realness (ASPR) to ensure stability of the system. The design involves a parallel feedforward compensator (PFC) which guarantees the ASPRness of the controlled system. After a disturbance the dynamical system is assumed to be in one of a finite number of configurations, corresponding to each of which exist a stabilizi...

  12. Minimal control power of the controlled teleportation

    Science.gov (United States)

    Jeong, Kabgyun; Kim, Jaewan; Lee, Soojoon

    2016-03-01

    We generalize the control power of a perfect controlled teleportation of an entangled three-qubit pure state, suggested by Li and Ghose [Phys. Rev. A 90, 052305 (2014), 10.1103/PhysRevA.90.052305], to the control power of a general controlled teleportation of a multiqubit pure state. Thus, we define the minimal control power, and calculate the values of the minimal control power for a class of general three-qubit Greenberger-Horne-Zeilinger (GHZ) states and the three-qubit W class whose states have zero three-tangles. Moreover, we show that the standard three-qubit GHZ state and the standard three-qubit W state have the maximal values of the minimal control power for the two classes, respectively. This means that the minimal control power can be interpreted as not only an operational quantity of a three-qubit quantum communication but also a degree of three-qubit entanglement. In addition, we calculate the values of the minimal control power for general n -qubit GHZ states and the n -qubit W -type states.

  13. Bifurcation Control, Manufacturing Planning and Formation Control

    Institute of Scientific and Technical Information of China (English)

    Wei Kang; Mumin Song; Ning Xi

    2005-01-01

    The paper consists of three topics on control theory and engineering applications, namely bifurcation control, manufacturing planning, and formation control. For each topic, we summarize the control problem to be addressed and some key ideas used in our recent research. Interested readers are referred to related publications for more details. Each of the three topics in this paper is technically independent from the other ones. However, all three parts together reflect the recent research activities of the first author, jointly with other researchers in different fields.

  14. Control and optimal control theories with applications

    CERN Document Server

    Burghes, D N

    2004-01-01

    This sound introduction to classical and modern control theory concentrates on fundamental concepts. Employing the minimum of mathematical elaboration, it investigates the many applications of control theory to varied and important present-day problems, e.g. economic growth, resource depletion, disease epidemics, exploited population, and rocket trajectories. An original feature is the amount of space devoted to the important and fascinating subject of optimal control. The work is divided into two parts. Part one deals with the control of linear time-continuous systems, using both transfer fun

  15. Process and apparatus for controlling control rods

    International Nuclear Information System (INIS)

    This process and apparatus is characterized by 2 methods, for examination of cluster of nuclear control rods. Foucault current analyzer which examines fraction by fraction all the control rods. This examination is made by rotation of the cluster. Doubtful rods are then analysed by ultrasonic probe

  16. Controllers' protoscripts and the shaping of control

    NARCIS (Netherlands)

    De Loo, I.G.M.; Nederhof, P.; Verstegen, B.

    2004-01-01

    The control mechanisms and instruments that eventually emerge in an organization are the result of a number of interrelated factors and processes. The design and construction of control instruments, the communication about them, the way in which the instruments are actually used, the processes of in

  17. Using data storage tags to link otolith macrostructure in Baltic cod Gadus morhua with environmental conditions

    DEFF Research Database (Denmark)

    Hüssy, Karin; Nielsen, Birgitte; Mosegaard, Henrik;

    2009-01-01

    in relation to these environmental drivers. Temperature was the only environmental variable with a significant effect, overlaying a strong size-related effect. The temperature effect was not uniform across behavioural types and spawning periods. Opacity showed a negative correlation with temperature...

  18. Development of Vestibular Stochastic Resonance as a Sensorimotor Countermeasure: Improving Otolith Ocular and Motor Task Responses

    Science.gov (United States)

    Mulavara, Ajitkumar; Fiedler, Matthew; DeDios,Yiri E.; Galvan, Raquel; Bloomberg, Jacob; Wood, Scott

    2011-01-01

    Astronauts experience disturbances in sensorimotor function after spaceflight during the initial introduction to a gravitational environment, especially after long-duration missions. Stochastic resonance (SR) is a mechanism by which noise can assist and enhance the response of neural systems to relevant, imperceptible sensory signals. We have previously shown that imperceptible electrical stimulation of the vestibular system enhances balance performance while standing on an unstable surface. The goal of our present study is to develop a countermeasure based on vestibular SR that could improve central interpretation of vestibular input and improve motor task responses to mitigate associated risks.

  19. Migration of diadromous and landlocked smelt populations studies by otolith geochemistry

    NARCIS (Netherlands)

    Phung, A.T.; Tulp, I.Y.M.; Baeyens, W.; Elskens, M.; Leermakers, M.; Gao, Y.

    2015-01-01

    Laser ablation inductively coupled mass spectrometry (LA-ICPMS) was used to determine Sr and Ba profiles along the growth axis of otholiths of European smelt caught in the Wadden Sea, the IJsselmeer and the Markermeer and to investigate the migration behaviour of the fish between the freshwater lake

  20. Chemical profiles in otoliths from 3 fish species along the Moroccan coast: accumulation and migration patterns

    Directory of Open Access Journals (Sweden)

    Maylis Labonne

    2015-11-01

    First results indicate that the concentrations are highly variable in hake transects, and on the other hand, transects in seabreams seem very stable regardless of location. Transects in sardines indicate different patterns depending on the locations and, some of them, clearly show the upwelling signature.

  1. [Characteristics of motion sickness during prolonged otolith stimulation in anti-orthostatic position].

    Science.gov (United States)

    Matsnev, E I; Iakovleva, I Ia; Serebrennikov, M I; Gavrilin, B K; Zakharova, L N; Nichiporuk, I A; Isupov, V G; Markin, A S

    1990-01-01

    Thirty healthy volunteers were tested for an extended period of time (up to 4 hours) on modified parallel swings during a head-down tilt (-8 degrees) study. The pattern of motion sickness that developed in this situation was evaluated in terms of physiological parameters (electrocardiography, rheoencephalography, arterial pressure, respiration rate electrooculography, etc.), hormonal status, fluid-electrolyte balance, sensory function. The test subjects developed a vestibulo-hemodynamic syndrome that included vestibular disorders, spatial illusions, fluid displacement in the cranial direction, excitation of the hypothalamic-pituitary-adrenal system, changes in fluid-electrolyte balance. The resulting data may help better understand mechanisms underlying motion sickness.

  2. Otoliths analysis of Mugil curema (Pisces: Mugilidae in Cuyutlan Lagoon, Mexico

    Directory of Open Access Journals (Sweden)

    E. Espino-Barr

    2013-01-01

    Full Text Available Se analizaron la morfología, la morfometría y los anillos de crecimiento de los otolitos: sagitta, asteriscus y lapillus de la lebrancha o liseta Mugil curema de la Laguna de Cuyutlán, Colima, México; asimismo, se analizaron las diferencias entre derecho e izquierdo y entre sexos. Los ejemplares fueron obtenidos de la captura comercial en los meses de agosto a octubre de 2007, agosto de 2008 y julio de 2011. En todos los casos se observó que el crecimiento de los otolitos es excéntrico con respecto al núcleo. Las relaciones entre la longitud total del pez y la longitud y ancho de los otolitos demostraron que esta estructura puede usarse para describir el crecimiento del pez. Se identificaron seis anillos de crecimiento en las sagittae y asterisci: especímenes con dos anillos midieron 21.80 cm de longitud total (TL (± 1.41 desviación estándar, los de tres anillos 22.90 (± 0.91, con cuatro anillos midieron 25.30 (± 0.39, con cinco anillos 28.30 (± 0.78 y con seis anillos 31.10 cm (± 2.22. En los lapilli, debido a su gran grosor, no fue posible observar marcas de crecimiento. Durante la etapa inmadura, los otolitos de las hembras son de mayor tamaño, pero una vez que alcanzan la madurez sexual, los otolitos de los machos alcanzan longitudes mayores.

  3. Matching Watershed and Otolith Chemistry to Establish Natal Origin of an Endangered Desert Lake Sucker

    OpenAIRE

    Strohm, Deanna

    2015-01-01

    Like many native endemic desert freshwater fish species, the June Sucker (Chasmistes liorus) is currently listed as endangered. Managers have increasingly turned to habitat restoration as a key component to recovery plans. For endangered species, one of the primary outcomes of habitat restoration is that it should result in successful reproduction and recruitment of individuals into the adult population. Confirmation of natural recruitment as a function of habitat restoration can only be achi...

  4. AFSC/ABL: Young of the year sablefish (Anoplopoma fimbria) voucher otoliths 1995-2004.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We studied young of the year sablefish Anoplopoma fimbria to collect basic life history information on their abundance, growth, and diet and to determine whether...

  5. Chaotic neural control

    Science.gov (United States)

    Potapov, A.; Ali, M. K.

    2001-04-01

    We consider the problem of stabilizing unstable equilibria by discrete controls (the controls take discrete values at discrete moments of time). We prove that discrete control typically creates a chaotic attractor in the vicinity of an equilibrium. Artificial neural networks with reinforcement learning are known to be able to learn such a control scheme. We consider examples of such systems, discuss some details of implementing the reinforcement learning to controlling unstable equilibria, and show that the arising dynamics is characterized by positive Lyapunov exponents, and hence is chaotic. This chaos can be observed both in the controlled system and in the activity patterns of the controller.

  6. HYDRAULIC SERVO CONTROL MECHANISM

    Science.gov (United States)

    Hussey, R.B.; Gottsche, M.J. Jr.

    1963-09-17

    A hydraulic servo control mechanism of compact construction and low fluid requirements is described. The mechanism consists of a main hydraulic piston, comprising the drive output, which is connected mechanically for feedback purposes to a servo control piston. A control sleeve having control slots for the system encloses the servo piston, which acts to cover or uncover the slots as a means of controlling the operation of the system. This operation permits only a small amount of fluid to regulate the operation of the mechanism, which, as a result, is compact and relatively light. This mechanism is particuiarly adaptable to the drive and control of control rods in nuclear reactors. (auth)

  7. Controlling neuronal noise using chaos control

    CERN Document Server

    Christini, D J; Christini, David J; Collins, James J

    1995-01-01

    Chaos control techniques have been applied to a wide variety of experimental systems, including magneto-elastic ribbons, lasers, chemical reactions, arrhythmic cardiac tissue, and spontaneously bursting neuronal networks. An underlying assumption in all of these studies is that the system being controlled is chaotic. However, the identification of chaos in experimental systems, particularly physiological systems, is a difficult and often misleading task. Here we demonstrate that the chaos criteria used in a recent study can falsely classify a noise-driven, non-chaotic neuronal model as being chaotic. We apply chaos control, periodic pacing, and anticontrol to the non-chaotic model and obtain results which are similar to those reported for apparently chaotic, {\\em in vitro} neuronal networks. We also obtain similar results when we apply chaos control to a simple stochastic system. These novel findings challenge the claim that the aforementioned neuronal networks were chaotic and suggest that chaos control tech...

  8. Undergraduate reactor control experiment

    International Nuclear Information System (INIS)

    A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise

  9. Foundations Of Fuzzy Control

    DEFF Research Database (Denmark)

    Jantzen, Jan

    The objective of this textbook is to acquire an understanding of the behaviour of fuzzy logic controllers. Under certain conditions a fuzzy controller is equivalent to a proportional-integral-derivative (PID) controller. Using that equivalence as a link, the book applies analysis methods from...... linear and nonlinear control theory. In the linear domain, PID tuning methods and stability analyses are transferred to linear fuzzy controllers. The Nyquist plot shows the robustness of different settings of the fuzzy gain parameters. As a result, a fuzzy controller is guaranteed to perform as well...... as any PID controller. In the nonlinear domain, the stability of four standard control surfaces is analysed by means of describing functions and Nyquist plots. The self-organizing controller (SOC) is shown to be a model reference adaptive controller. There is a possibility that a nonlinear fuzzy PID...

  10. CONTROLLING AND BUSINESS EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Tina Vuko

    2013-02-01

    Full Text Available Managing business successfully in dynamic environment requires effective controlling system. Controlling is the process of defining objectives, planning and management control so that every decision maker can act in accordance with agreed objectives. Controlling function as a separate department contributes business efficiency trough ensuring transparency of business result and business processes. Controlling takes place when manager and controller cooperate. The aim of this paper is to investigate the effectiveness of controlling function (i.e. controlling department in Croatian companies and to address the specific features of the function that contribute significantly to overall business performance. The research is conducted on the sample of companies listed on the Regulated market of the Zagreb Stock Exchange. Survey is used as a method to collect the data regarding the controlling function, while financial data necessary for the research are extracted from the published financial statements. Results of the research indicate that controlling department has positive effects on the business performance.

  11. Controller Architectures for Switching

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2009-01-01

    This paper investigate different controller architectures in connection with controller switching. The controller switching is derived by using the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization. A number of different architectures for the implementation of the YJBK parameterization are...... described and applied in connection with controller switching. An architecture that does not include inversion of the coprime factors is introduced. This architecture will make controller switching particular simple....

  12. Controlling chaos in Internet congestion control model

    International Nuclear Information System (INIS)

    The TCP end-to-end congestion control plus RED router queue management can be modeled as a discrete-time dynamical system, which may create complex bifurcating and chaotic behavior. Based on the basic features of the TCP-RED model, we propose a time-dependent delayed feedback control algorithm to control chaos in the system by perturbing the accessible RED parameter pmax. This method is able to stabilized a router queue occupancy at a level without knowing the exact knowledge of the network. Further, we study the situation of the presence of the UDP traffic

  13. Vehicle Dynamics and Control

    CERN Document Server

    Rajamani, Rajesh

    2012-01-01

    Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system applications covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire-road friction coefficient estimation, rollover prevention, and hybrid electric vehicle. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics. A special effort has been made to explain the several different tire models commonly used in literature and to interpret them physically. In the second edition of the book, chapters on roll dynamics, rollover prevention and hybrid electric vehicles have been added, and the chapter on electronic stability co...

  14. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Søren

    This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust...... and control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves...... an ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control...

  15. Control system design method

    Science.gov (United States)

    Wilson, David G.; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  16. Step Motor Control System

    Institute of Scientific and Technical Information of China (English)

    ZhangShuochengt; WangDan; QiaoWeimin; JingLan

    2003-01-01

    All kinds of step motors and servomotors are widely used in CSR control system, such as many vacuum valves control that set on the HIRFL-CSR; all kinds of electric switches and knobs of ECR Ion Source; equipment of CSR Beam Diagnostics and a lot of large equipment like Inside Gun Toroid and Collector Toroid of HIRFL. A typical control system include up to 32 16-I/O Control boards, and each 16-I/O Control board can control 4 motors at the same time (including 8 Limit Switches).

  17. Controllable Elastohydrodynamics With Examples

    DEFF Research Database (Denmark)

    Santos, Ilmar; Haugaard, Martin Asger

    sleeves and active lubricated bearings belongs to a special category of tribological devices where “controllable” elastohydrodynamics plays an crucial role. In such devices the bearing surface profile is intentionally modified and/or adjusted in order to control rotor vibrations and improve bearing......-pad journal bearing under hybrid elastohydrodynamics (open loop control) as well as controllable radial oil injection (closed loop control). The bearing dynamic coefficients are heavily influenced by the control parameters and pad compliance. Strong synergy between elastohydrodynamics and active control...

  18. Control integral systems; Sistemas integrales de control

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Estrella [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    Almost two third of the electric power generation in Mexico are obtained from hydrocarbons, for that reasons Comision Federal de Electricidad (CFE) dedicated special commitment in modernizing the operation of fossil fuel central stations. In attaining this objective the control systems play a fundamental roll, from them depend a good share of the reliability and the efficiency of the electric power generation process, as well as the extension of the equipment useful life. Since 1984 the Instituto de Investigaciones Electricas (IIE) has been working, upon the request of CFE, on the development of digital control systems. To date it has designed and implemented a logic control system for gas burners, which controls 32 burners of the Unit 4 boiler of the Generation Central of Valle de Mexico and two systems for distributed control for two combined cycle central stations, which are: Dos Bocas, Veracruz Combined cycle central, and Gomez Palacio, Durango combined cycle central. With these two developments the IIE enters the World tendency of implementing distributed control systems for the fossil fuel power central update [Espanol] Casi las dos terceras partes de la generacion electrica en Mexico se obtienen a partir de hidrocarburos, es por eso que la Comision Federal de Electricidad (CFE) puso especial empeno en modernizar la operacion de las centrales termoelectricas de combustibles fosiles. En el logro de este objetivo los sistemas de control desempenan un papel fundamental, de ellos depende una buena parte la confiabilidad y la eficiencia en el proceso de generacion de energia electrica, asi como la prolongacion de la vida util de los equipos. Desde 1984 el Instituto de Investigaciones Electricas (IIE) ha trabajado, a solicitud de la CFE, en el desarrollo de sistemas digitales de control. A la fecha se han disenado e implantado un sistema de control logico de quemadores de gas, el cual controla 32 quemadores de la caldera de la unidad 4 de la central de generacion

  19. Guaranteed cost control for networked control systems

    Institute of Scientific and Technical Information of China (English)

    Linbo XIE; Huajing FANG; Ying ZHENG

    2004-01-01

    The guaranteed cost control problem for networked control systems (NCSs) is addressed under communication constraints and varying sampling rate. First of all, a simple information-scheduling scheme is presented to describe the scheduling approach of system signals in NCSs. Then, based on such a scheme and given sampling method, the design procedure in dynamic output feedback manner is also derived which renders the closed loop system to be asymptotically stable and guarantees an upper bound of the LQ performance cost function.

  20. Modeling and control of thermostatically controlled loads

    OpenAIRE

    Kundu, Soumya; Sinitsyn, Nikolai; Backhaus, Scott; Hiskens, Ian

    2011-01-01

    As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for...

  1. Advanced Emissions Control Development Program: Mercury Control

    International Nuclear Information System (INIS)

    McDermott Technology, Inc. (a subsidiary of Babcock ampersand Wilcox) is conducting the Advanced Emissions Control Development Project (AECDP) which is aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (HAPS) from coal-fired electric utility plants. The need for such controls may arise as the US Environmental Protection Agency (EPA) proceeds with implementation of requirements set forth in the Clean Air Act Amendments (CAAA's) of 1990. Promulgation of air toxics emissions regulations for electric utility plants could dramatically impact utilities burning coal, their industrial and residential customers, and the coal industry. AECDP project work will supply the information needed by utilities to respond to potential HAPs regulations in a timely, cost-effective, enviromnentally-sound manner which supports the continued use of the Nation's abundant reserves of coal, such as those in the State of Ohio. The development work is being carried out using the 10 MW Clean Environment Development Facility wherein air toxics emissions control strategies can be developed under controlled conditions. The specific objectives of the project are to (1) measure and understand production and partitioning of air toxics species for a variety of coals, (2) optimize the air toxics removal performance of conventional flue gas cleanup systems, (3) develop advanced air toxics emissions control concepts, (4) develop and validate air toxics emissions measurement and monitoring techniques, and (5) establish a comprehensive, self-consistent air toxics data library. This project is supported by the Department of Energy, the Ohio Coal Development Office within the Ohio Department of Development and Babcock ampersand Wilcox. A comprehensive assessment of HAP emissions from coal-fired electric utility boilers sponsored by the Department of Energy and the Electric Power Research Institute concluded that with the exception of

  2. A modular control system

    International Nuclear Information System (INIS)

    The main objective of the modular control system is to provide the requirements to most of the processes supervision and control applications within the industrial automatization area. The design is based on distribution, modulation and expansion concepts. (Author)

  3. TIPONLINE Control Table

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The tiponline application is quite complex.It contains code, control,use local lists and control data. Those whou care about the inter workings of the application...

  4. Nutrient Control Seminars

    Science.gov (United States)

    These Nutrient Control Seminars will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). These seminars will present ...

  5. Poison Control Centers

    Science.gov (United States)

    ... 1222 immediately. Name State American Association of Poison Control Centers Address AAPCC Central Office NOT A POISON ... not for emergency use. Arkansas ASPCA Animal Poison Control Center Address 1717 S. Philo Road, Suite 36 Urbana, ...

  6. Birth Control Explorer

    Science.gov (United States)

    ... Relationships STIs Media Facebook Twitter Tumblr Shares · 5 Birth Control Explorer Sort by all methods most effective methods ... 100% effective method of birth control. LEARN MORE IUD An IUD is a T-shaped device that ...

  7. NGS Survey Control Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Survey Control Map provides a map of the US which allows you to find and display geodetic survey control points stored in the database of the National...

  8. Making up Corruption Control

    DEFF Research Database (Denmark)

    Krause Hansen, Hans; Tang-Jensen, Morten Hove

    2015-01-01

    Contemporary scholarship on corruption control lacks an analytical focus on anti-corruption in practice. We examine corruption control at the micro-level as exemplified by the use of anti-corruption due diligence in a Danish law firm. Building on concepts from studies of the cultural economy, anti...... control work. By providing also an extended view on the operations of due diligence in the wider corruption control regime the paper problematizes clear-cut distinctions and categories used in established literatures....

  9. Design of Fuzzy Controllers

    DEFF Research Database (Denmark)

    Jantzen, Jan

    1998-01-01

    Design of a fuzzy controller requires more design decisions than usual, for example regarding rule base, inference engine, defuzzification, and data pre- and post processing. This tutorial paper identifies and describes the design choices related to single-loop fuzzy control, based on an...... international standard which is underway. The paper contains also a design approach, which uses a PID controller as a starting point. A design engineer can view the paper as an introduction to fuzzy controller design....

  10. DSP controlled power converter

    OpenAIRE

    Chan, CH; Pong, MH

    1995-01-01

    A digital controller is designed and implemented by a Digital Signal Processor (DSP) to replace the Pulse Width Modulator (PWM) and error amplifier compensation network in a two wheeler forward converter. The DSP controller is designed in three approaches: a) Discretization of analog controller - the design is based on the transfer function of the error amplifier compensation network. b) Digital PID controller design - the design is based on the general form of the pulse transfer function of ...

  11. Fuzzy Control Tutorial

    DEFF Research Database (Denmark)

    Dotoli, M.; Jantzen, Jan

    1999-01-01

    The tutorial concerns automatic control of an inverted pendulum, especially rule based control by means of fuzzy logic. A ball balancer, implemented in a software simulator in Matlab, is used as a practical case study. The objectives of the tutorial are to teach the basics of fuzzy control......, and to show how to apply fuzzy logic in automatic control. The tutorial is distance learning, where students interact one-to-one with the teacher using e-mail....

  12. PC Controlled Home Appliances

    Directory of Open Access Journals (Sweden)

    Laxmi Soni

    2014-05-01

    Full Text Available With advancement of technology things are becoming simpler and easier for us. Automated systems are being preferred over manual system. PC based control systems are highly reliable, accurate and time saving systems. They provide number of features like quick data storage, transfer data and data securities which helps in industries to work in sufficient manner. A microcontroller based controller is designed to control a number of electrical equipment. To control and monitor connected equipment through the PC.

  13. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

    Hansen, M. R.; Andersen, T. O.; Nielsen, B.;

    2003-01-01

    This paper present and discusses R&D results on electro hydraulic hitch control for off-road vehicle, in particular active damping of oscillation occuring on tractors. The research deals with analysis and control of the oscillations occuring on tractors which are design without any susspection...... for a parameter research study with emphasis on the requirements to the hitch control by use of hydraulic pressure compensated proportional control valve....

  14. Robust Self Tuning Controllers

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad

    1985-01-01

    The present thesis concerns robustness properties of adaptive controllers. It is addressed to methods for robustifying self tuning controllers with respect to abrupt changes in the plant parameters. In the thesis an algorithm for estimating abruptly changing parameters is presented. The estimator...... has several operation modes and a detector for controlling the mode. A special self tuning controller has been developed to regulate plant with changing time delay....

  15. Defining Quantum Control Flow

    OpenAIRE

    Ying, Mingsheng; Yu, Nengkun; Feng, Yuan

    2012-01-01

    A remarkable difference between quantum and classical programs is that the control flow of the former can be either classical or quantum. One of the key issues in the theory of quantum programming languages is defining and understanding quantum control flow. A functional language with quantum control flow was defined by Altenkirch and Grattage [\\textit{Proc. LICS'05}, pp. 249-258]. This paper extends their work, and we introduce a general quantum control structure by defining three new quantu...

  16. Unbundling Ownership and Control

    OpenAIRE

    Ferreira, Daniel; Ornelas, Emanuel; Turner, John L.

    2007-01-01

    Treating control as an asset that can be bought and sold, we introduce a model of the simultaneous and separable trading of ownership and control in a private information setting. The model provides a novel explanation for the prevalence and persistence of the separation of ownership from control in modern corporations: efficiency in the market for corporate control is more easily achieved when ownership is not concentrated in the hands of the manager. The central reason is that low manageria...

  17. Integrated Control and Scheduling

    OpenAIRE

    Årzén, Karl-Erik; Bernhardsson, Bo; Eker, Johan; Cervin, Anton; Nilsson, Klas; Persson, Patrik; Sha, Lui

    1999-01-01

    The report gives a state-of-the-art survey of the field of integrated control and scheduling. Subtopics discussed are implementation and scheduling of periodic control loops, scheduling under overload, control and scheduling co-design, dynamic task adaptation, feedback scheduling, and scheduling of imprecise calculations. The report also presents the background, motivation, and research topics in the ARTES project Integrated Control and Scheduling.

  18. On Controlled P Systems

    OpenAIRE

    Krithivasan, Kamala; Paun, Gheorghe; Ramanujan, Ajeesh; Research Group on Natural Computing (Universidad de Sevilla) (Coordinador)

    2013-01-01

    We introduce and brie y investigate P systems with controlled computations. First, P systems with label restricted transitions are considered (in each step, all rules used have either the same label, or, possibly, the empty label, ), then P systems with the computations controlled by languages (as in context-free controlled grammars). The relationships between the families of sets of numbers computed by the various classes of controlled P systems are investigated, also comp...

  19. Cooperative Control Method of Active and Semiactive Control: New Framework for Vibration Control

    OpenAIRE

    Kazuhiko Hiramoto

    2014-01-01

    A new control design framework for vibration control, the cooperative control of active and semiactive control, is proposed in the paper. In the cooperative control, a structural system having both of an actuator and a semiactive control device, for example, MR damper and so forth, is defined as the control object. In the proposed control approach, the higher control performance is aimed by the cooperative control between the active control with the actuator and the semiactive control with th...

  20. Adaptive, predictive controller for optimal process control

    Energy Technology Data Exchange (ETDEWEB)

    Brown, S.K.; Baum, C.C.; Bowling, P.S.; Buescher, K.L.; Hanagandi, V.M.; Hinde, R.F. Jr.; Jones, R.D.; Parkinson, W.J.

    1995-12-01

    One can derive a model for use in a Model Predictive Controller (MPC) from first principles or from experimental data. Until recently, both methods failed for all but the simplest processes. First principles are almost always incomplete and fitting to experimental data fails for dimensions greater than one as well as for non-linear cases. Several authors have suggested the use of a neural network to fit the experimental data to a multi-dimensional and/or non-linear model. Most networks, however, use simple sigmoid functions and backpropagation for fitting. Training of these networks generally requires large amounts of data and, consequently, very long training times. In 1993 we reported on the tuning and optimization of a negative ion source using a special neural network[2]. One of the properties of this network (CNLSnet), a modified radial basis function network, is that it is able to fit data with few basis functions. Another is that its training is linear resulting in guaranteed convergence and rapid training. We found the training to be rapid enough to support real-time control. This work has been extended to incorporate this network into an MPC using the model built by the network for predictive control. This controller has shown some remarkable capabilities in such non-linear applications as continuous stirred exothermic tank reactors and high-purity fractional distillation columns[3]. The controller is able not only to build an appropriate model from operating data but also to thin the network continuously so that the model adapts to changing plant conditions. The controller is discussed as well as its possible use in various of the difficult control problems that face this community.

  1. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...

  2. Control in Complex Organizations

    DEFF Research Database (Denmark)

    Rennstam, Jens; Kärreman, Dan

    The extant research on organizational control builds on the assumption of vertical control – managers are thought to develop orders, rules and norms to control the operating core. Yet it is claimed that work becomes increasingly “knowledge intensive” and that organizations rely heavily for their ...

  3. Riot Control Agents

    Science.gov (United States)

    ... a person has been exposed to riot control agents. Long-term health effects of exposure to riot control agents Prolonged ... person is removed from exposure to riot control agents, long-term health effects are unlikely to occur. How you can ...

  4. Optimisation of load control

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P. [VTT Energy, Espoo (Finland)

    1998-08-01

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  5. Methods for structural control

    OpenAIRE

    Baratta, A.; Bourquin, F.; CORBI, O; HOCHRAINER, M; Luo, N; MAGONETTE, G; Marazzi, F; Rodellar, J.

    2004-01-01

    In the last decades significant advances have been produced in the field of structural control. This paper focuses on some issues related with the problem of controlling (reducing) undesired vibrations, summarizing the experiences of the authors in some specific issues on specific classes of structural control systems.

  6. Robust Adaptive Structural Control

    OpenAIRE

    Yang, Chi-Ming; Beck, James L.

    1995-01-01

    A new robust adaptive structural control design methodology is developed and presented which treats modeling uncertainties and limitations of control devices. Furthermore, no restriction is imposed on the structural models and the nature of the control devices so that the proposed method is very general. A simple linear single degree-of-freedom numerical example is presented to illustrate this approach.

  7. Airship formation control

    OpenAIRE

    Bicho, E.; Moreira, André; Diegues, Sérgio; Carvalheira, Manuel Pereira; Monteiro, Sérgio

    2006-01-01

    This paper addresses the problem underlying the control and coordination of multiple autonomous airships that must travel maintaining a desired geometric formation and simultaneously avoid collisions with moving or stationary obstacles. The control architecture is based on the attractor dynamics approach to behaviour generation. The airship physical model is presented and the mathematical background for the control architecture is explained. Simulations (with perturbations) ...

  8. Robust control of accelerators

    Science.gov (United States)

    Joel, W.; Johnson, D.; Chaouki, Abdallah T.

    1991-07-01

    The problem of controlling the variations in the rf power system can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. Because of the modelling uncertainty, one has to design either a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and, therefore, shall not be pursued in this research. In contrast, the robust control method leads to simpler hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) has led to the development and implementation of a new robust rf power feedback system. In this article, we report on our research progress. In section 1, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section 2, the results of our proof-of-principle experiments are presented. In section 3, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf. without demodulating, compensating, and then remodulating.

  9. Informal control code logic

    OpenAIRE

    Bergstra, J. A.

    2010-01-01

    General definitions as well as rules of reasoning regarding control code production, distribution, deployment, and usage are described. The role of testing, trust, confidence and risk analysis is considered. A rationale for control code testing is sought and found for the case of safety critical embedded control code.

  10. Robot Visual Control

    OpenAIRE

    Chaumette, François

    2015-01-01

    International audience; This article describes the basic concepts of vision-based control, that is, the use of visual data to control the motions of a robotics system. It describes the modeling steps allowing the design of kinematics control schemes. Applications are also described.

  11. Informal Control code logic

    CERN Document Server

    Bergstra, Jan A

    2010-01-01

    General definitions as well as rules of reasoning regarding control code production, distribution, deployment, and usage are described. The role of testing, trust, confidence and risk analysis is considered. A rationale for control code testing is sought and found for the case of safety critical embedded control code.

  12. SPS : the control system

    CERN Multimedia

    CERN Neyrac Films

    1975-01-01

    English version. Part of the series of films produced by CERN about the SPS. "More than 10.000 things to control, 7,00 things to measure and 30,000 ? to survey, distributed over more than 10 square km. That was the problem which faced the controls group." Comments: images of control room, computer screens, and computer centre rather dark

  13. Survivability via Control Objectives

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL,PHILIP L.

    2000-08-11

    Control objectives open an additional front in the survivability battle. A given set of control objectives is valuable if it represents good practices, it is complete (it covers all the necessary areas), and it is auditable. CobiT and BS 7799 are two examples of control objective sets.

  14. Customs control of goods

    Directory of Open Access Journals (Sweden)

    Mentor Gashi

    2015-11-01

    Full Text Available Customs control, is regulated by law in different countries. Different countries define through the law, the control of goods.. Main purpose of this paper is to analyze two types of customs controls, and their effect in reducing avoidance of duty or tax evasion which may be caused by the import of goods of certain companies. For this reason we researched which model is implemented in developing countries and what results were reached through questionnaires. In this sense the next research question, consists in defining the moment of customs control pre or post-clearance control of goods.

  15. Magnetically Controlled Variable Transformer

    Science.gov (United States)

    Kleiner, Charles T.

    1994-01-01

    Improved variable-transformer circuit, output voltage and current of which controlled by use of relatively small current supplied at relatively low power to control windings on its magnetic cores. Transformer circuits of this type called "magnetic amplifiers" because ratio between controlled output power and power driving control current of such circuit large. This ratio - power gain - can be as large as 100 in present circuit. Variable-transformer circuit offers advantages of efficiency, safety, and controllability over some prior variable-transformer circuits.

  16. Controlling the intelligent building

    Energy Technology Data Exchange (ETDEWEB)

    LeBlanc, R.J.

    1985-08-01

    Companies will be able to locate in intelligent buildings that offer access to a variety of sophisticated communications equipment, at the heart of which are building controls that ensure a comfortable and safe working environment for the occupants. Future buildings will include advanced telephones or workstations with built-in building control sensors for temperature, light level, and security. Advanced telecommunication systems may have telephone cabinets with built-in control functions which eliminate the need for discrete control systems. The owners and tenants will both enjoy benefits if the controls are carefully selected and designed so that they integrate into a single building package.

  17. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....

  18. Optimal magnetic attitude control

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Markley, F.L.

    1999-01-01

    Magnetic torquing is attractive as means of control for small satellites. The actuation principle is to use the interaction between the earth's magnetic field and a magnetic field generated by a coil set in the satellite. This control principle is inherently time-varying, and difficult to use...... because control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis stabilization of a low earth orbit satellite. The problem of controlling the spacecraft attitude using only magnetic...

  19. Induction motor control design

    CERN Document Server

    Marino, Riccardo; Verrelli, Cristiano M

    2010-01-01

    ""Nonlinear and Adaptive Control Design for Induction Motors"" is a unified exposition of the most important steps and concerns in the design of estimation and control algorithms for induction motors. A single notation and modern nonlinear control terminology is used to make the book accessible to readers who are not experts in electric motors at the same time as giving a more theoretical control viewpoint to those who are. In order to increase readability, the book concentrates on the induction motor, eschewing the much more complex and less-well-understood control of asynchronous motors. The

  20. Modeling and control of thermostatically controlled loads

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, Scott N [Los Alamos National Laboratory; Sinitsyn, Nikolai [Los Alamos National Laboratory; Kundu, S. [UNIV OF MICHIGAN; Hiskens, I. [UNIV OF MICHIGAN

    2011-01-04

    As the penetration of intermittent energy sources grows substantially, loads will be required to play an increasingly important role in compensating the fast time-scale fluctuations in generated power. Recent numerical modeling of thermostatically controlled loads (TCLs) has demonstrated that such load following is feasible, but analytical models that satisfactorily quantify the aggregate power consumption of a group of TCLs are desired to enable controller design. We develop such a model for the aggregate power response of a homogeneous population of TCLs to uniform variation of all TCL setpoints. A linearized model of the response is derived, and a linear quadratic regulator (LQR) has been designed. Using the TCL setpoint as the control input, the LQR enables aggregate power to track reference signals that exhibit step, ramp and sinusoidal variations. Although much of the work assumes a homogeneous population of TCLs with deterministic dynamics, we also propose a method for probing the dynamics of systems where load characteristics are not well known.

  1. Integrated Biological Control

    International Nuclear Information System (INIS)

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response

  2. Control, salud y bienestar

    Directory of Open Access Journals (Sweden)

    Salas-Auvert, Jesús A.

    2008-09-01

    Full Text Available En resumen, a pesar de que en algunas circunstancias, la exagerada percepción o necesidad de control es contraproducente para la adaptación y crecimiento psicológico, la aceptación general es que, al menos en grado moderado, el control percibido y control real son beneficios para las personas y un recurso valioso para enfrentar las dificultades en la vida. Por ello, las personas, grupos y naciones buscan sentirse dueñas de sus destinos y no víctimas de las circunstancias. Las personas y los pueblos con control son las que moldean y transforman las circunstacias, los que construyen un futuro mejor. Por ello, con objetivos preventivos y remediativos, los profesionales de la salud mental debemos promover el desarrollo y optimizacion de un control moderado y flexible como nutriente del crecimiento psicológico y bienestar biopsicosocial individual y colectivo. El trabajo aborda el significado del control, el desarrollo del control real y percibido, la relación entre control, salud y enfermedad, control, bienestar y psicopatología, la renuncia a los intentos de control, y control y terapia cognitivo-conductual.

  3. Motion control systems

    CERN Document Server

    Sabanovic, Asif

    2011-01-01

    "Presents a unified approach to the fundamental issues in motion control, starting from the basics and moving through single degree of freedom and multi-degree of freedom systems In Motion Control Systems, Šabanovic and Ohnishi present a unified approach to very diverse issues covered in motion control systems, offering know-how accumulated through work on very diverse problems into a comprehensive, integrated approach suitable for application in high demanding high-tech products. It covers material from single degree of freedom systems to complex multi-body non-redundant and redundant systems. The discussion of the main subject is based on original research results and will give treatment of the issues in motion control in the framework of the acceleration control method with disturbance rejection technique. This allows consistent unification of different issues in motion control ranging from simple trajectory tracking to topics related to haptics and bilateral control without and with delay in the measure...

  4. Advanced AC Motor Control

    Energy Technology Data Exchange (ETDEWEB)

    Kazmierkowski, M.P. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warszawa (Poland)

    1997-12-31

    In this paper a review of control methods for high performance PWM inverter-fed induction motor drives is presented. Starting from the description of an induction motor by the help of the space vectors, three basic control strategic are discussed. As first, the most popular Field Oriented Control (FOC) is described. Secondly, the Direct Torque and Flux vector Control (DTFC) method, which - in contrast to FOC - depart from idea of coordinate transformation and analogy with DC motor, is briefly characterized. The last group is based on Feedback Linearization Control (FLC) and can be easy combined with sliding mode control. The simulation and experimental oscillograms that illustrate the performance of the discussed control strategies are shown. (orig.) 35 refs.

  5. The Parrot UAV Controlled by PID Controllers

    Directory of Open Access Journals (Sweden)

    Koszewnik Andrzej

    2014-08-01

    Full Text Available The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered directions.

  6. Research on Dual Control

    Institute of Scientific and Technical Information of China (English)

    Duan Li; Fucai Qian; Peilin Fu

    2005-01-01

    This paper summarizes recent progress by the authors in developing two solution frameworks for dual control. The first solution framework considers a class of dual control problems where there exists a parameter uncertainty in the observation equation of the LQG problem. An analytical active dual control law is derived by a variance minimization approach. The issue of how to determine an optimal degree of active learning is then addressed, thus achieving an optimality for this class of dual control problems. The second solution framework considers a general class of discrete-time LQG problems with unknown parameters in both state and observation equations. The best possible (partial) closed-loop feedback control law is derived by exploring the future nominal posterior probabilities, thus taking into account the effect of future learning when constructing the optimal nominal dual control.

  7. Quality Control Applications

    CERN Document Server

    Chorafas, Dimitris N

    2013-01-01

    Quality control is a constant priority in electrical, mechanical, aeronautical, and nuclear engineering – as well as in the vast domain of electronics, from home appliances to computers and telecommunications. Quality Control Applications provides guidance and valuable insight into quality control policies; their methods, their implementation, constant observation and associated technical audits. What has previously been a mostly mathematical topic is translated here for engineers concerned with the practical implementation of quality control. Once the fundamentals of quality control are established, Quality Control Applications goes on to develop this knowledge and explain how to apply it in the most effective way. Techniques are described and supported using relevant, real-life, case studies to provide detail and clarity for those without a mathematical background. Among the many practical examples, two case studies dramatize the importance of quality assurance: A shot-by-shot analysis of the errors made ...

  8. Debt Out of Control

    DEFF Research Database (Denmark)

    Achtziger, Anja; Hubert, Marco; Kenning, Peter;

    2015-01-01

    In a representative sample of the German population (n = 946), we explored the links between self-control, compulsive buying, and debts. Participants completed the self-control scale (Tangney, Boone, & Baumeister, 2004) and the German Addictive Buying Scale (Raab, Neuner, Reisch, & Scherhorn, 2005......). Additionally, they gave information about their real debts. It was observed that self-control was negatively related to debts while compulsive buying was positively related to debts. Detailed analyses revealed that the link between self-control and debts was fully mediated by compulsive buying. Finally......, there was a gender effect on compulsive buying: women were more prone to compulsive buying than men. Age also was significantly negatively related to compulsive buying and positively linked to self-control. Household income was not linked to self-control, compulsive buying, and debts. Implications for practice...

  9. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

    Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

  10. Reset Control Systems

    CERN Document Server

    Baños, Alfonso

    2012-01-01

    Reset Control Systems addresses the analysis for reset control treating both its basic form which requires only that the state of the controller be reinitialized to zero (the reset action) each time the tracking error crosses zero (the reset condition), and some useful variations of the reset action (partial reset with fixed or variable reset percentage) and of the reset condition (fixed or variable reset band and anticipative reset). The issues regarding reset control – concepts and motivation; analysis tools; and the application of design methodologies to real-world examples – are given comprehensive coverage. The text opens with an historical perspective which moves from the seminal work of the Clegg integrator and Horowitz FORE to more recent approaches based on impulsive/hybrid control systems and explains the motivation for reset compensation. Preliminary material dealing with notation, basic definitions and results, and with the definition of the control problem under study is also included. The fo...

  11. Reactor control rod

    International Nuclear Information System (INIS)

    Object: To enable quick descent of a control rod body even when some relative phase deviation between upper drive means and wrapper tube is produced, while permitting a coolant to effectively flow into a protective tube irrespective of the position of the control rod body. Structure: In a control rod used for a nuclear reactor such as a fast breeder, an orifice which dispenses with a cylindrical guide tube and has a greater inner diameter than the outer diameter of the protective tube of the control rod body is provided on the inner side of a wrapper tube, thus permitting smooth operation of the control rod body and also permitting the coolant to effectively flow into the protective tube irrespective of the control rod body. (Horiuchi, T.)

  12. Trends in furnace control

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.J.; Keefe, M.D. (Italimpianti of America, Inc., Coraopolis, PA (United States). Instrumentation and Controls Dept.)

    1993-07-01

    This paper relates Italimpianti's experiences over the past few years in the area of control of reheat furnaces for the steel industry. The focus is on the level 1 area; specifically on the use of PLC-based systems to perform both combustion control and mechanical/hydraulic control. Some topics to be discussed are: overview of reheat furnace control system requirements; PLC only control vs separate PLC and DCS systems; PLC hardware requirements; man machine interface (MMI) requirements; purge, light-on and safety logic; implementation of more sophisticated level 1 control algorithms; furnace temperature optimization: look up tables vs full thermal modeling; and recent trends including integrated PLC/DCS system.

  13. Unpacking Self-Control

    Science.gov (United States)

    Duckworth, Angela; Steinberg, Laurence

    2014-01-01

    Self-controlled behavior refers to actions aligned with valued, longer-term goals in the face of conflicting impulses to seek immediate gratification. In this article, we argue that the psychological processes that contribute to self-controlled behavior can be grouped into two functionally distinct categories: Volitional processes facilitate self-controlled behavior and include executive functions as well as learned metacognitive strategies like planning, attention deployment, and psychological distancing. In contrast, impulsigenic processes undermine self-controlled behavior and include reward sensitivity, sensation seeking, and domain-specific cravings. A disproportionate amount of research has addressed the former at the expense of understanding individual and developmental differences in the latter. This imbalance is now being rectified. Distinguishing between self-controlled behavior and its antecedent psychological processes helps illuminate normative developmental changes in self-control and points to directions for measurement and intervention. PMID:25821515

  14. Discrete Control Systems

    CERN Document Server

    Lee, Taeyoung; McClamroch, N Harris

    2007-01-01

    Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of geometric integration. Geometric integrators are numerical integration methods that preserve geometric properties of continuous systems, such as conservation of the symplectic form, momentum, and energy. They also guarantee that the discrete flow remains on the manifold on which the continuous system evolves, an important property in the case of rigid-body dynamics. In nonlinear control, one typically relies on differential geometric and dynamical systems techniques to prove properties such as stability, controllability, and optimality. More generally, the geometric structure of such systems plays a critical role in the nonlinear analysis of the corresponding control problems. Despite the critical role of geometry and mechanics in the analysis of nonlinear control systems, non...

  15. Spacecraft momentum control systems

    CERN Document Server

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  16. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Søren

    2010-01-01

    The purpose of this paper is to show that conceptualizing trust and control as interactively related processes, as opposed to more static conceptualizations of the two concepts and the relations between them, adds importantly towards understanding the challenges involved in balancing of trust...... and control in organizations. The paper examines recent literature on the conceptualization of the relation between trust and control in and between organizations. The literature review shows that trust and control has been conceptualized as either substituting or complementing each other. Further......, it is found that the complementary/substitution debate calls for an explicit conceptualization of the relation between trust and control as an interactive process, in contrast to earlier conceptualizations of trust and control as two relatively static and isolated concepts. While the static perspective...

  17. Tautological control systems

    CERN Document Server

    Lewis, Andrew D

    2014-01-01

    This brief presents a description of a new modelling framework for nonlinear/geometric control theory. The framework is intended to be—and shown to be—feedback-invariant. As such, Tautological Control Systems provides a platform for understanding fundamental structural problems in geometric control theory. Part of the novelty of the text stems from the variety of regularity classes, e.g., Lipschitz, finitely differentiable, smooth, real analytic, with which it deals in a comprehensive and unified manner. The treatment of the important real analytic class especially reflects recent work on real analytic topologies by the author. Applied mathematicians interested in nonlinear and geometric control theory will find this brief of interest as a starting point for work in which feedback invariance is important. Graduate students working in control theory may also find Tautological Control Systems to be a stimulating starting point for their research.

  18. Statistical Engine Knock Control

    DEFF Research Database (Denmark)

    Stotsky, Alexander A.

    2008-01-01

    A new statistical concept of the knock control of a spark ignition automotive engine is proposed . The control aim is associated with the statistical hy pothesis test which compares the threshold value to the average value of the max imal amplitud e of the knock sensor signal at a given freq uency...... which includ es generation of the amplitud e signals, a threshold value d etermination and a knock sound mod el is d eveloped for evaluation of the control concept....

  19. Towards "Propagation = Logic + Control"

    OpenAIRE

    Brand, Sebastian; Yap, Roland H. C.

    2006-01-01

    Constraint propagation algorithms implement logical inference. For efficiency, it is essential to control whether and in what order basic inference steps are taken. We provide a high-level framework that clearly differentiates between information needed for controlling propagation versus that needed for the logical semantics of complex constraints composed from primitive ones. We argue for the appropriateness of our controlled propagation framework by showing that it c...

  20. Molluscicides in schistosomiasis control

    OpenAIRE

    McCullough, F. S.; Gayral, Ph.; Duncan, J.; Christie, J. D.

    1980-01-01

    Although mollusciciding can be a cost-effective method of controlling schistosomiasis transmission, only one organic molluscicide, niclosamide, is now being produced commercially, and only a few compounds are at present being tested in the laboratory. In future, improved cost-effective use of molluscicides will require more precise knowledge of schistosomiasis transmission patterns in each endemic area and improved application techniques. In snail control studies using controlled-release form...

  1. Enabling Versus Controlling

    OpenAIRE

    Hagiu, Andrei; Wright, Julian

    2015-01-01

    In an increasing number of industries, firms choose how much control to give professionals over the provision of their services to clients. We study the tradeoffs that arise in choosing between a traditional mode (where the firm takes control of service provision) and a platform mode (where professionals retain control over service provision). The choice of mode is determined by the need to balance two-sided moral hazard problems arising from investments that only professionals can make and i...

  2. Temperature measurement and control

    CERN Document Server

    Leigh, JR

    1988-01-01

    This book treats the theory and practice of temperature measurement and control and important related topics such as energy management and air pollution. There are no specific prerequisites for the book although a knowledge of elementary control theory could be useful. The first half of the book is an application oriented survey of temperature measurement techniques and devices. The second half is concerned mainly with temperature control in both simple and complex situations.

  3. Efficiency in Controlling Activities

    OpenAIRE

    Van Nguyen, Tuyen

    2015-01-01

    Controlling is essential for financial success of corporations. An efficient controlling system should be implemented in order to manage financial performance from income, expense to profitability. The purpose of the thesis is to provide insight knowledge towards corporate accounting management as well as to propose potential improvement for the existing controlling system of the case company, which is Bosch Rexroth Japan. The theoretical framework creates the knowledge foundation for re...

  4. Structural control interaction

    Science.gov (United States)

    Ryan, R. S.; Mowery, D. K.; Winder, S. W.; Worley, H. E.

    1973-01-01

    The basic guidance and control concepts that lead to structural control interaction and structural dynamic loads are identified. Space vehicle ascent flight load sources and the load relieving mechanism are discussed, along with the the characteristics and special problems of both present and future space vehicles including launch vehicles, orbiting vehicles, and the Space Shuttle flyback vehicle. The special dynamics and control analyses and test problems apparent at this time are summarized.

  5. Mead photovoltaic system controller

    Energy Technology Data Exchange (ETDEWEB)

    Millner, A.R.

    1979-01-31

    A system controller has been designed, built, tested, and in operation for one year at MIT/Lincoln Laboratory's 25-kW-peak Solar Photovoltaic Power System located at Mead, Nebraska. The controller allows the site to operate without human intervention, and has brought to light some of the problems of charge-control algorithms in a deep-discharge environment.

  6. Quantum wavefunction controllability

    Science.gov (United States)

    Turinici, Gabriel; Rabitz, Herschel

    2001-06-01

    Theoretical results are presented on the ability to arbitrarily steer about a wavefunction for a quantum system under time-dependent external field control. Criteria on the field free Hamiltonian and the field coupling term in the Hamiltonian are presented that assure full wavefunction controllability. Numerical simulations are given to illustrate the criteria. A discussion on the theoretical and practical relationship between dynamical conservation laws and controllability is also included.

  7. Intelligent PID controllers

    OpenAIRE

    Fliess, Michel; Join, Cédric

    2008-01-01

    International audience; Intelligent PID controllers, or i-PID controllers, are PID controllers where the unknown parts of the plant, which might be highly nonlinear and/or time-varying, are taken into account without any modeling procedure. Our main tool is an online numerical differentiator, which is based on easily implementable fast estimation and identification techniques. Several numerical experiments demonstrate the efficiency of our method when compared to more classic PID regulators.

  8. Model-free control

    OpenAIRE

    Fliess, Michel; Join, Cédric

    2013-01-01

    International audience; ''Model-free control'' and the corresponding ''intelligent'' PID controllers (iPIDs), which already had many successful concrete applications, are presented here for the first time in an unified manner, where the new advances are taken into account. The basics of model-free control is now employing some old functional analysis and some elementary differential algebra. The estimation techniques become quite straightforward via a recent online parameter identification ap...

  9. Controls for unstable structures

    Science.gov (United States)

    Guenther, Oliver; Hogg, Tad; Huberman, Bernardo A.

    1997-06-01

    We study the behavior of several organizations for a market based distributed control of unstable physical systems and show how a hierarchical organization is a reasonable compromise between rapid local responses with simple communication and the use of global knowledge. We also introduce a new control organization, the multihierarchy, and show that is uses less power than a hierarchy in achieving stability. The multihierarchy also has a position invariant response that can control disturbances at the appropriate scale and location.

  10. Optimal Control for Dummies

    Directory of Open Access Journals (Sweden)

    Marcus Davidsson

    2012-06-01

    Full Text Available The aim of this study is to facilitate the teaching of optimal control in economics. Understanding optimal control can be challenging to say the least. This study discusses optimal control and its applications in economics. More specifically the famous Keynesian-Ramsey rule will be explored and discussed in detail. The same rule is also extensively used in resource economics to calculate the optimal extraction from for example a gold mine.

  11. The energy control

    International Nuclear Information System (INIS)

    Because of strong constraints, the energy control has not been a priority of the public choices. With the market liberalization, the framework of the energy control is modified. But the new program became not sufficient. This study aims to present the necessary new policy of the energy control, which must be integrated in the attitudes and must imply the local government. (A.L.B.)

  12. Control component retainer

    International Nuclear Information System (INIS)

    An apparatus is described for retaining an undriven control component assembly disposed in a fuel assembly in a nuclear reactor of the type having a core grid plate. The first part of the mechanism involves a housing for the control component and the second part is a brace with a number of arms that reach under the grid plate. The brace and the housing are coupled together to firmly hold the control components in place even under strong flows of th coolant

  13. Tagging vs. Controlled Vocabulary

    DEFF Research Database (Denmark)

    Bogers, Toine; Petras, Vivien

    2015-01-01

    elements like core bibliographic data, controlled vocabulary terms, reviews, and tags to the retrieval performance. Our comparison is done using a test collection of over 2 million book records with information elements from Amazon, the British Library, the Library of Congress, and LibraryThing. We find...... that tags and controlled vocabulary terms do not actually outperform each other consistently, but seem to provide complementary contributions: some information needs are best addressed using controlled vocabulary terms whereas other are best addressed using tags....

  14. ISTTOK control system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

    2013-10-15

    Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 μs control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 μs during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel{sup ®} Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators.

  15. Unpacking Self-Control

    OpenAIRE

    Duckworth, Angela; Steinberg, Laurence

    2015-01-01

    Self-controlled behavior refers to actions aligned with valued, longer-term goals in the face of conflicting impulses to seek immediate gratification. In this article, we argue that the psychological processes that contribute to self-controlled behavior can be grouped into two functionally distinct categories: Volitional processes facilitate self-controlled behavior and include executive functions as well as learned metacognitive strategies like planning, attention deployment, and psychologic...

  16. Controlled Fuzzy Parallel Rewriting

    OpenAIRE

    Asveld, Peter R.J.

    1996-01-01

    We study a Lindenmayer-like parallel rewriting system to model the growth of filaments (arrays of cells) in which developmental errors may occur. In essence this model is the fuzzy analogue of the derivation-controlled iteration grammar. Under minor assumptions on the family of control languages and on the family of fuzzy languages in the underlying iteration grammar, we show that (i) regular control does not provide additional generating power to the model, (ii) the number of fuzzy substitut...

  17. Controlled Fuzzy Parallel Rewriting

    OpenAIRE

    Asveld, Peter R.J.; Paun, G.; Salomaa, A

    1997-01-01

    We study a Lindenmayer-like parallel rewriting system to model the growth of filaments (arrays of cells) in which developmental errors may occur. In essence this model is the fuzzy analogue of the derivation-controlled iteration grammar. Under minor assumptions on the family of control languages and on the family of fuzzy languages in the underlying iteration grammar, we show (i) regular control does not provide additional generating power to the model, (ii) the number of fuzzy substitutions ...

  18. Lithography process control

    CERN Document Server

    Levinson, Harry J

    1999-01-01

    This text covers lithography process control at several levels, from fundamental through advanced topics. The book is a self-contained tutorial that works both as an introduction to the technology and as a reference for the experienced lithographer. It reviews the foundations of statistical process control as background for advanced topics such as complex processes and feedback. In addition, it presents control methodologies that may be applied to process development pilot lines.

  19. The ISOLDE control system

    Science.gov (United States)

    Deloose, I.; Pace, A.

    1994-12-01

    The two CERN isotope separators named ISOLDE have been running on the new Personal Computer (PC) based control system since April 1992. The new architecture that makes heavy use of the commercial software and hardware of the PC market has been implemented on the 1700 geographically distributed control channels of the two separators and their experimental area. Eleven MSDOS Intel-based PCs with approximately 80 acquisition and control boards are used to access the equipment and are controlled from three PCs running Microsoft Windows used as consoles through a Novell Local Area Network. This paper describes the interesting solutions found and discusses the reduced programming workload and costs that have been obtained.

  20. Control functions in MFM

    DEFF Research Database (Denmark)

    Lind, Morten

    2011-01-01

    Multilevel Flow Modeling (MFM) has been proposed as a tool for representing goals and functions of complex industrial plants and suggested as a basis for reasoning about control situations. Lind presents an introduction to MFM but do not describe how control functions are used in the modeling....... The purpose of the present paper is to serve as a companion paper to this introduction by explaining the basic principles used in MFM for representation of control functions. A theoretical foundation for modeling control functions is presented and modeling examples are given for illustration....

  1. Chemical crowd control agents.

    Science.gov (United States)

    Menezes, Ritesh G; Hussain, Syed Ather; Rameez, Mansoor Ali Merchant; Kharoshah, Magdy A; Madadin, Mohammed; Anwar, Naureen; Senthilkumaran, Subramanian

    2016-03-01

    Chemical crowd control agents are also referred to as riot control agents and are mainly used by civil authorities and government agencies to curtail civil disobedience gatherings or processions by large crowds. Common riot control agents used to disperse large numbers of individuals into smaller, less destructive, and more easily controllable numbers include chloroacetophenone, chlorobenzylidenemalononitrile, dibenzoxazepine, diphenylaminearsine, and oleoresin capsicum. In this paper, we discuss the emergency medical care needed by sufferers of acute chemical agent contamination and raise important issues concerning toxicology, safety and health. PMID:26658556

  2. Tokamak burn control

    International Nuclear Information System (INIS)

    Research of the fusion plasma thermal instability and its control is reviewed. General models of the thermonuclear plasma are developed. Techniques of stability analysis commonly employed in burn control research are discussed. Methods for controlling the plasma against the thermal instability are reviewed. Emphasis is placed on applications to tokamak confinement concepts. Additional research which extends the results of previous research is suggested. Issues specific to the development of control strategies for mid-term engineering test reactors are identified and addressed. 100 refs., 24 figs., 10 tabs

  3. Detonation command and control

    Science.gov (United States)

    Mace, Jonathan L.; Seitz, Gerald J.; Echave, John A.; Le Bas, Pierre-Yves

    2015-11-10

    The detonation of one or more explosive charges and propellant charges by a detonator in response to a fire control signal from a command and control system comprised of a command center and instrumentation center with a communications link therebetween. The fire control signal is selectively provided to the detonator from the instrumentation center if plural detonation control switches at the command center are in a fire authorization status, and instruments, and one or more interlocks, if included, are in a ready for firing status. The instrumentation and command centers are desirably mobile, such as being respective vehicles.

  4. Intelligent networked teleoperation control

    CERN Document Server

    Li, Zhijun; Su, Chun-Yi

    2015-01-01

    This book describes a unified framework for networked teleoperation systems involving multiple research fields: networked control systems for linear and nonlinear forms, bilateral teleoperation, trilateral teleoperation, multilateral teleoperation and cooperative teleoperation. It closely examines networked control as a field at the intersection of systems & control and robotics and presents a number of experimental case studies on testbeds for robotic systems, including networked haptic devices, robotic network systems and sensor network systems. The concepts and results outlined are easy to understand, even for readers fairly new to the subject. As such, the book offers a valuable reference work for researchers and engineers in the fields of systems & control and robotics.

  5. Fuzzy control and identification

    CERN Document Server

    Lilly, John H

    2010-01-01

    This book gives an introduction to basic fuzzy logic and Mamdani and Takagi-Sugeno fuzzy systems. The text shows how these can be used to control complex nonlinear engineering systems, while also also suggesting several approaches to modeling of complex engineering systems with unknown models. Finally, fuzzy modeling and control methods are combined in the book, to create adaptive fuzzy controllers, ending with an example of an obstacle-avoidance controller for an autonomous vehicle using modus ponendo tollens logic.

  6. COMPUTER BASED ENVIRONMENT CONTROLS

    OpenAIRE

    Macoveiciuc Pastorel

    2011-01-01

    The aim of these notes is to give an overview of the main activities of computer based activities controls. The basic principles of computer controls should be common to all sectors and to most types of hardware and software. The absence of a common definition of computer control may, in part, be due to the relative newness of computer controls. A key feature of many organisations today is change. Although not necessarily the driver of change, IT is invariably an intrinsec component and much ...

  7. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  8. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  9. The arms race control

    International Nuclear Information System (INIS)

    Written in 1961, this paper presents the content of a book entitled 'The arms race control' where the author outlined the difference between disarmament and arms control, described the economic and moral role of arms race, the importance of force balance for international security. He wandered whether arms control could ensure this balance and whether nuclear balance meant force balance. Force balance then appears to be a precarious and unsteady component of international security. He commented the challenges of disarmament, recalled some arguments for a nuclear disarmament. Then he discussed what would be an arms control with or without disarmament (either nuclear or conventional)

  10. Mechatronics control technology

    International Nuclear Information System (INIS)

    This book consists six chapters, which are an assembler grammar and practical use on Z801 8041/8048 and kind of assemblers and how to use, control of a microprocessor and mechatro with application of 8255, interface circuit and direction of DA converter, control of stepping motor such as introduction of it, sequence switch, drive program of stepping motor, control for DC motor such as normal rotation and abnormal rotation operation of DC motor by personal computer, control AC motor like PWM inverter and data communication among systems such as RS-232C and INTEL-HEXA format program.

  11. Resisting religious coercive control.

    Science.gov (United States)

    Sharp, Shane

    2014-12-01

    Religious coercive control refers to the use of religious beliefs and doctrine as means to coercively control intimate partners. Scholars have shown that some abusive partners use the Christian doctrine of submission as a means of religious coercive control. I explore how victims who experience the doctrine of submission qua religious coercive control actively resist it. I argue that victims' successful resistance of the doctrine is contingent on their religious capital-that is, the knowledge and mastery that people have of a particular religious culture-and interpretive confidence-that is, people's subjective confidence in their interpretations of religious culture-related to the doctrine. PMID:25398370

  12. An integrated gyrotron controller

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Georg, E-mail: michel@ipp.mpg.de; Sachtleben, Juergen

    2011-10-15

    The ECRH system of W7-X is composed of 10 independent gyrotron modules. Each module consists of one gyrotron and its peripherals such as power supplies, cooling plants and distributed PLC systems. The fast real-time control functions such as the timing of the two high voltage supplies, trigger pulses, protection, modulation and communication with the central control of W7-X, is implemented in an integrated controller which is described in this paper. As long-term maintainability and sustainability are important for nuclear fusion experiments, the choice fell on an FPGA-based design which is exclusively based on free (as in 'freedom') software and configuration code. The core of the controller consists of a real-time Java virtual machine (JVM) that provides the TCP-IP connectivity as well as more complicated control functions, and which interacts with the gyrotron-specific hardware. Both the gyrotron-specific hardware and the JVM are implemented on the same FPGA, which is the main component of the controller. All 10 controllers are currently completed and operational. All parameters and functions are accessible via Ethernet. Due to the open, FPGA-based design, most hardware modifications can be made via the network as well. This paper discusses the capabilities of the controllers and their integration into the central W7-X control.

  13. Control system design guide

    Energy Technology Data Exchange (ETDEWEB)

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  14. Detonation command and control

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Jonathan L.; Seitz, Gerald J.; Echave, John A.; Le Bas, Pierre-Yves

    2016-05-31

    The detonation of one or more explosive charges and propellant charges by a detonator in response to a fire control signal from a command and control system comprised of a command center and instrumentation center with a communications link there between. The fire control signal is selectively provided to the detonator from the instrumentation center if plural detonation control switches at the command center are in a fire authorization status, and instruments, and one or more interlocks, if included, are in a ready for firing status. The instrumentation and command centers are desirably mobile, such as being respective vehicles.

  15. Device Oriented Project Controller

    Energy Technology Data Exchange (ETDEWEB)

    Dalesio, Leo; Kraimer, Martin

    2013-11-20

    This proposal is directed at the issue of developing control systems for very large HEP projects. A de-facto standard in accelerator control is the Experimental Physics and Industrial Control System (EPICS), which has been applied successfully to many physics projects. EPICS is a channel based system that requires that each channel of each device be configured and controlled. In Phase I, the feasibility of a device oriented extension to the distributed channel database was demonstrated by prototyping a device aware version of an EPICS I/O controller that functions with the current version of the channel access communication protocol. Extensions have been made to the grammar to define the database. Only a multi-stage position controller with limit switches was developed in the demonstration, but the grammar should support a full range of functional record types. In phase II, a full set of record types will be developed to support all existing record types, a set of process control functions for closed loop control, and support for experimental beam line control. A tool to configure these records will be developed. A communication protocol will be developed or extensions will be made to Channel Access to support introspection of components of a device. Performance bench marks will be made on both communication protocol and the database. After these records and performance tests are under way, a second of the grammar will be undertaken.

  16. MOSFET Power Controller

    Science.gov (United States)

    Mitchell, J.; Jones, K.

    1986-01-01

    High current and voltage controlled remotely. Remote Power Conroller includes two series-connected banks of parallel-connected MOSFET's to withstand high current and voltage. Voltage sharing between switch banks, low-impedance, gate-drive circuits used. Provided controlled range for turn on. Individually trimmable to insure simultaneous switching within few nanoseconds during both turn on and turn off. Control circuit for each switch bank and over-current trip circuit float independently and supplied power via transformer T1 from inverter. Control of floating stages by optocouplers.

  17. Controls for space structures

    Science.gov (United States)

    Balas, Mark

    1991-01-01

    Assembly and operation of large space structures (LSS) in orbit will require robot-assisted docking and berthing of partially-assembled structures. These operations require new solutions to the problems of controls. This is true because of large transient and persistent disturbances, controller-structure interaction with unmodeled modes, poorly known structure parameters, slow actuator/sensor dynamical behavior, and excitation of nonlinear structure vibrations during control and assembly. For on-orbit assembly, controllers must start with finite element models of LSS and adapt on line to the best operating points, without compromising stability. This is not easy to do, since there are often unmodeled dynamic interactions between the controller and the structure. The indirect adaptive controllers are based on parameter estimation. Due to the large number of modes in LSS, this approach leads to very high-order control schemes with consequent poor stability and performance. In contrast, direct model reference adaptive controllers operate to force the LSS to track the desirable behavior of a chosen model. These schemes produce simple control algorithms which are easy to implement on line. One problem with their use for LSS has been that the model must be the same dimension as the LSS - i.e., quite large. A control theory based on the command generator tracker (CGT) ideas of Sobel, Mabins, Kaufman and Wen, Balas to obtain very low-order models based on adaptive algorithms was developed. Closed-loop stability for both finite element models and distributed parameter models of LSS was proved. In addition, successful numerical simulations on several LSS databases were obtained. An adaptive controller based on our theory was also implemented on a flexible robotic manipulator at Martin Marietta Astronautics. Computation schemes for controller-structure interaction with unmodeled modes, the residual mode filters or RMF, were developed. The RMF theory was modified to compensate

  18. Robust CUSUM control charting

    NARCIS (Netherlands)

    H.Z. Nazir; M. Riaz; R.J.M.M. Does; N. Abbas

    2013-01-01

    Cumulative sum (CUSUM) control charts are very effective in detecting special causes. In general, the underlying distribution is supposed to be normal. In designing a CUSUM chart, it is important to know how the chart will respond to disturbances of normality. The focus of this article is to control

  19. CONTROL OF REPRODUCTION

    Science.gov (United States)

    Control of reproduction is important for seed stock production, selective breeding, growth rate, feed efficiency, meat quality, and biosecurity. These needs to control reproduction differ among cultivars and even segments of the same industry. No matter the impetus for aquaculturists to want to alte...

  20. Control of schistosomiasis transmission

    Directory of Open Access Journals (Sweden)

    Luiz C. de S. Dias

    1995-04-01

    Full Text Available Despite the success of control programmes, schistosomiasis is still a serious public health problem in the world. More than 70 countries where 200 million individuals are evaluated to be infected of a total 600 million at risk. Though there have been important local success in the control of transmission, globally the infection has increased. Economic constrains in developing countries, environmental changes associated with migration and water resources development have been blocking the progress. The main objective of schistosomiasis control is to achieve reduction of disease due to schistosomiasis. We discussed the control measures like: health education, diagnosis and chemotherapy, safe water supplies, sanitation and snail control. We emphasized the need to give priority to school-age children and the importance of integrating the measures of control into locally available systems of health care. The control of schistosomiasis is directly related to the capacity of the preventive health services of an endemic country. The strategy of control requires long-term commitment from the international to the local level.

  1. Optimal obstacle control problem

    Institute of Scientific and Technical Information of China (English)

    ZHU Li; LI Xiu-hua; GUO Xing-ming

    2008-01-01

    In the paper we discuss some properties of the state operators of the optimal obstacle control problem for elliptic variational inequality. Existence, uniqueness and regularity of the optimal control problem are established. In addition, the approximation of the optimal obstacle problem is also studied.

  2. Resisting Mind Control.

    Science.gov (United States)

    Anderson, Susan M.; Zimbardo, Philip G.

    1980-01-01

    Provides conceptual analyses of mind control techniques along with practical advice on how to resist these techniques. The authors stress that effective mind control stems more from everyday social relations than from exotic technological gimmicks. Suggestions are given for resisting persuasion, resisting systems, and challenging the system.…

  3. Mustard meal weed control

    Science.gov (United States)

    Weed control in organic production systems can be a labor intensive and expensive process. Mustard meal (MM) is phytotoxic and a potential pre-emergent and preplant-incorporated organic herbicide for controlling germinating and emerging weed seedlings. Unfortunately, MM may also adversely impact s...

  4. Joystick controller for JIWY

    NARCIS (Netherlands)

    Lammertink, Tijs

    2003-01-01

    JIWY is a mechatronic device with two rotational degrees of freedom, with a camera as its `end effector¿. JIWY can be controlled with a joystick. Each joint is steered by a joystick axis. The x-axis and the y-axis control the horizontal joint respectively the vertical joint. A model of the total sys

  5. Ship Roll Motion Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    . This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

  6. Checking quality control?

    DEFF Research Database (Denmark)

    Brodersen, Lars

    2005-01-01

    How is quality control doing within the community of GIS, web-services based on geo-information, GI etc.?......How is quality control doing within the community of GIS, web-services based on geo-information, GI etc.?...

  7. PS Control Room

    CERN Multimedia

    1963-01-01

    The good old PS Control Room, all manual. For each parameter, a knob or a button to control it; for each, a light or meter or oscilloscope to monitor it; carefully written pages serve as the data bank; phones and intercom for communication. D.Dekkers is at the microphone, M.Valvini sits in front.

  8. Advanced Control Engineering

    DEFF Research Database (Denmark)

    Zhou, Jianjun

    1999-01-01

    This book is developed as a textbook for the course Advanced Control Engineering. The book is intended for students in mechanical engineering and its aim is to provide an understanding of modern control theory as well as methodologies and applications for state space modeling and design...

  9. Proxemic-aware controls

    DEFF Research Database (Denmark)

    Ledo, David; Greenberg, Saul; Marquardt, Nicolai;

    2015-01-01

    Remote controls facilitate interactions at-a-distance with appliances. However, the complexity, diversity, and in-creasing number of digital appliances in ubiquitous com-puting ecologies make it increasingly difficult to: (1) dis-cover which appliances are controllable; (2) select a par-ticular a......Remote controls facilitate interactions at-a-distance with appliances. However, the complexity, diversity, and in-creasing number of digital appliances in ubiquitous com-puting ecologies make it increasingly difficult to: (1) dis-cover which appliances are controllable; (2) select a par......-ticular appliance from the large number available; (3) view information about its status; and (4) control the ap-pliance in a pertinent manner. To mitigate these problems we contribute proxemic-aware controls, which exploit the spatial relationships between a person's handheld de-vice and all surrounding appliances...... to create a dynamic appliance control interface. Specifically, a person can discover and select an appliance by the way one orients a mobile device around the room, and then progressively view the appliance's status and control its features in in-creasing detail by simply moving towards it. We illus...

  10. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier;

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  11. Food irradiation control

    International Nuclear Information System (INIS)

    A brief review is given of the control and monitoring of food irradiation with particular emphasis on the UK situation. After describing legal aspects, various applications of food irradiation in different countries are listed. Other topics discussed include code of practice for general control for both gamma radiation and electron beam facilities, dose specification, depth dose distribution and dosimetry. (U.K.)

  12. Atomic Energy Control Board

    International Nuclear Information System (INIS)

    This paper has been prepared to provide an overview of the responsibilities and activities of the Atomic Energy Control Board. It is designed to address questions that are often asked concerning the establishment of the Atomic Energy Control Board, its enabling legislation, licensing and compliance activities, federal-provincial relationships, international obligations, and communications with the public

  13. Public Health Pest Control.

    Science.gov (United States)

    Arizona Univ., Tucson. Cooperative Extension Service.

    This manual supplies information helpful to individuals wishing to become certified in public health pest control. It is designed as a technical reference for vector control workers and as preparatory material for structural applicators of restricted use pesticides to meet the General Standards of Competency required of commercial applicators. The…

  14. Contamination Control Techniques

    Energy Technology Data Exchange (ETDEWEB)

    EBY, J.L.

    2000-05-16

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

  15. Contamination Control Techniques

    International Nuclear Information System (INIS)

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics

  16. Controlling Electronics Boards with PVS

    CERN Multimedia

    2005-01-01

    - Introduction - Control System Architecture - Device Description - FPGA Programming - Register Control - Data Subscription - Examples of Graphics User Interfaces - Parameter - Register Translation - Application on the LHCb Timing Fast Control System

  17. Uncertainty and Cognitive Control

    Directory of Open Access Journals (Sweden)

    Faisal eMushtaq

    2011-10-01

    Full Text Available A growing trend of neuroimaging, behavioural and computational research has investigated the topic of outcome uncertainty in decision-making. Although evidence to date indicates that humans are very effective in learning to adapt to uncertain situations, the nature of the specific cognitive processes involved in the adaptation to uncertainty are still a matter of debate. In this article, we reviewed evidence suggesting that cognitive control processes are at the heart of uncertainty in decision-making contexts. Available evidence suggests that: (1 There is a strong conceptual overlap between the constructs of uncertainty and cognitive control; (2 There is a remarkable overlap between the neural networks associated with uncertainty and the brain networks subserving cognitive control; (3 The perception and estimation of uncertainty might play a key role in monitoring processes and the evaluation of the need for control; (4 Potential interactions between uncertainty and cognitive control might play a significant role in several affective disorders.

  18. A TRNSYS microprocessor controller

    Science.gov (United States)

    Piessens, L. P.; Beckman, W. A.; Mitchell, J. W.

    A truth table approach is employed to model the operation of a microprocessor controller for a solar energy system. Using the simulation code TRNSYS, a parameter is added to stop iteration procedures which potentially could become endless as the program seeks a solution to a set of governing equations at the same time as a pump or switch is turned off, thus creating a stable mode of iteration. The simulation of control logic also includes comparisons between input signals in order to arrive at a choice of output control signals. Temperatures are the normal input signals, and additional input may be mass flow rate, insolation, and night setbacks. Techniques for identifying typographical errors in the control logic are explored, as are the effects of the time step size chosen. Results are presented of simulations of month-long operation of a solar system and primary loop control strategies.

  19. Cell Control Engineering

    DEFF Research Database (Denmark)

    Lynggaard, Hans Jørgen Birk; Alting, Leo

    1996-01-01

    The engineering process of creating cell control systems is described, and a Cell Control Engineering (CCE) concept is defined. The purpose is to assist people, representing different disciplines in the organisation, to implement cell controllers by addressing the complexity of having many systems...... in physically and logically different and changing manufacturing environments. The defined CCE concept combines state-of-the-art of commercially available enabling technologies for automation system software development, generic cell control models and guidelines for the complete engineering process....... It facilitates the understanding of the task and structure of cell controllers and uses this knowledge directly in the implementation of the system. By applying generic models CCE facilitates reuse of software components and maintenance of applications. In many enterprises, software makes up an increasing part...

  20. Fractional Dynamics and Control

    CERN Document Server

    Machado, José; Luo, Albert

    2012-01-01

    Fractional Dynamics and Control provides a comprehensive overview of recent advances in the areas of nonlinear dynamics, vibration and control with analytical, numerical, and experimental results. This book provides an overview of recent discoveries in fractional control, delves into fractional variational principles and differential equations, and applies advanced techniques in fractional calculus to solving complicated mathematical and physical problems.Finally, this book also discusses the role that fractional order modeling can play in complex systems for engineering and science. Discusses how fractional dynamics and control can be used to solve nonlinear science and complexity issues Shows how fractional differential equations and models can be used to solve turbulence and wave equations in mechanics and gravity theories and Schrodinger’s equation  Presents factional relaxation modeling of dielectric materials and wave equations for dielectrics  Develops new methods for control and synchronization of...

  1. Environmental control technology

    International Nuclear Information System (INIS)

    The objective of the overall Environmental Control Technology Program is to assure that the environmental control capability for each ERDA energy technology is complete, practical, cost effective, and available in a timely manner as the energy source is developed. Program activities are oriented to identifying control technology status and needs for emerging energy systems, then developing methods and equipment for meeting these needs. Progress is reported on studies in support of both nonnuclear and nuclear technologies, with programs in oil shale, coal, energy materials transport, and nuclear fuel cycle analysis. Results are reported from studies on the environmental control technology treatment of oil shale; the assessment of environmental control technologies for commercial coal gasification; transportation safety studies; transportation problems for 1976 to 2000; a safety and economic study of special trains; development of high-level waste shipping cask models; analysis of nuclear fuel cycles; toxic materials in the nuclear fuel cycle; and decontamination and decommissioning of retired contaminated ERDA facilities at Hanford

  2. Control of flexible structures

    Science.gov (United States)

    Russell, R. A.

    1985-01-01

    The requirements for future space missions indicate that many of these spacecraft will be large, flexible, and in some applications, require precision geometries. A technology program that addresses the issues associated with the structure/control interactions for these classes of spacecraft is discussed. The goal of the NASA control of flexible structures technology program is to generate a technology data base that will provide the designer with options and approaches to achieve spacecraft performance such as maintaining geometry and/or suppressing undesired spacecraft dynamics. This technology program will define the appropriate combination of analysis, ground testing, and flight testing required to validate the structural/controls analysis and design tools. This work was motivated by a recognition that large minimum weight space structures will be required for many future missions. The tools necessary to support such design included: (1) improved structural analysis; (2) modern control theory; (3) advanced modeling techniques; (4) system identification; and (5) the integration of structures and controls.

  3. Controlling Quantum Information

    CERN Document Server

    Landahl, A J

    2002-01-01

    Quantum information science explores ways in which quantum physical laws can be harnessed to control the acquisition, transmission, protection, and processing of information. This field has seen explosive growth in the past several years from progress on both theoretical and experimental fronts. Essential to this endeavor are methods for controlling quantum information. In this thesis, I present three new approaches for controlling quantum information. First, I present a new protocol for continuously protecting unknown quantum states from noise. This protocol combines and expands ideas from the theories of quantum error correction and quantum feedback control. The result can outperform either approach by itself. I generalize this protocol to all known quantum stabilizer codes, and study its application to the three-qubit repetition code in detail via Monte Carlo simulations. Next, I present several new protocols for controlling quantum information that are fault-tolerant. These protocols require only local qu...

  4. Discrete control systems

    CERN Document Server

    Okuyama, Yoshifumi

    2014-01-01

    Discrete Control Systems establishes a basis for the analysis and design of discretized/quantized control systemsfor continuous physical systems. Beginning with the necessary mathematical foundations and system-model descriptions, the text moves on to derive a robust stability condition. To keep a practical perspective on the uncertain physical systems considered, most of the methods treated are carried out in the frequency domain. As part of the design procedure, modified Nyquist–Hall and Nichols diagrams are presented and discretized proportional–integral–derivative control schemes are reconsidered. Schemes for model-reference feedback and discrete-type observers are proposed. Although single-loop feedback systems form the core of the text, some consideration is given to multiple loops and nonlinearities. The robust control performance and stability of interval systems (with multiple uncertainties) are outlined. Finally, the monograph describes the relationship between feedback-control and discrete ev...

  5. Control systems under attack?

    CERN Document Server

    Lüders, Stefan

    2005-01-01

    The enormous growth of the Internet during the last decade offers new means to share and distribute both information and data. In Industry, this results in a rapprochement of the production facilities, i.e. their Process Control and Automation Systems, and the data warehouses. At CERN, the Internet opens the possibility to monitor and even control (parts of) the LHC and its four experiments remotely from anywhere in the world. However, the adoption of standard IT technologies to Distributed Process Control and Automation Systems exposes inherent vulnerabilities to the world. The Teststand On Control System Security at CERN (TOCSSiC) is dedicated to explore the vulnerabilities of arbitrary Commercial-Of-The-Shelf hardware devices connected to standard Ethernet. As such, TOCSSiC should discover their vulnerabilities, point out areas of lack of security, and address areas of improvement which can then be confidentially communicated to manufacturers. This paper points out risks of accessing the Control and Automa...

  6. Discrete Variational Optimal Control

    CERN Document Server

    Jimenez, Fernando; de Diego, David Martin

    2012-01-01

    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher-dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical and a practical examples, e.g. the control of an underwater vehicle, will illustrate the application of the proposed approach.

  7. Control of Multilayer Networks

    CERN Document Server

    Menichetti, Giulia; Bianconi, Ginestra

    2015-01-01

    The controllability of a network is a theoretical problem of relevance in a variety of contexts ranging from financial markets to the brain. Until now, network controllability has been characterized only on isolated networks, while the vast majority of complex systems are formed by multilayer networks. Here we build a theoretical framework for the linear controllability of multilayer networks by mapping the problem into a combinatorial matching problem. We found that correlating the external signals in the different layers can significantly reduce the multiplex network robustness to node removal, as it can be seen in conjunction with a hybrid phase transition occurring in interacting Poisson networks. Moreover we observe that multilayer networks can stabilize the fully controllable multiplex network configuration that can be stable also when the full controllability of the single network is not stable.

  8. Effects of altered gravity on the expression of Calcium -binding and matrix proteins in the inner ear of developing fish following ∆g-expositions.

    Science.gov (United States)

    Hilbig, Reinhard; Hendrik Anken, Ralf; Weigele, Jochen

    The results of the Foton-M3 mission (OmegaHab) give evidence that the otoliths of the fish form OmegaHab were larger as compared to the ground control. Additionally the shape (raphe) and morphology especially the mode of crystallization of the otoliths were affected during growth in weightlessness. The reason for these changes is assumed to originate from changes in the composition of the otolith matrix and Ca-binding proteins (OMP). The OMPs play an important role in controlling the crystallization process and additionally the morphology of crystals, determining the crystallpolymorph and the strength of the crystals. The matrix of otoliths is a complex functional structure containing several calcium-binding proteins, structural proteins and protease inhibitors. Furthermore it is composed of otolith matrix protein-1, Otolin, Otoconin, SPARC and Neuroserpin, which is a specific expression in the otolth matrix for chichlid fish. During embryonic development of the fish inner ear, these proteins show a spacial and temporal expression pattern. The formation of the inner ear -including otoliths and sensory cells -starting from the otocyst-anlage -can be subdivided in several major developmental stages e.g. the forming of the otic cavity (stage 7/8), the tetha cell or seeding stage (stage 8, 9), the development of the semicircular channels (stage 12), the transition to further daily growth (post stage15) and the development of the third otolith, asteriscus (stage 23). These developmental phases contain different constitutions or involvements of matrix proteins. We investigated the matrixprotein composition of the chichlid fish Oreochromis mossambicus and found that the otolith matrix differentiate between other fishes. In this case some matrix proteins seem to be uniform in fishes, other known matrix proteins are lacking and we have also references to new candidates for matrix proteins chichlids. In this case we investigated the expression of the matrix proteins otolith

  9. CONCEPTUAL DELIMITATIONS OF CONTROLLING

    Directory of Open Access Journals (Sweden)

    Nedelcu Serban

    2011-12-01

    Full Text Available CONCEPTUAL DELIMITATIONS OF CONTROLLING Nedelcu Serban Universitatea ,,Babes-Bolyai`` Facultatea de Stiinte Economice si Gestiunea Afacerilor 'Controlling' represents a new concept in the Romanian economic environement, being implemented successfully in very few companies. Unlike the German space where controlling is very well represented both at a practical level and in the academia, in Romania controlling can only be found at a practical level, and the specialized literature is restraint, almost absent. Since the practicians of controlling in Romania only know the toolkit they use and not the theoretical elements as well, what is needed in this case is a conceptual delimitation so that controlling would be better implemented, and improved with various elements of the economic environment. In practice, inside various linguistic areas different problems of communication may occur very often in regards to the use of different concepts that may be missunderstood. Therefore in the Romanian research area it becomes imperative to try and clarify the existing issues and to intensify the reasearch in this field. Studying the evolution of the concept we observe that the need for its implementation is primarily experienced at the practical level of the companies, to be then followed by a debate in the specialized literature. The internationalization and the fierce competition that the Romanian companies are confronting on the ecenomic market represent the decissive factor in adopting the concept of controlling.This article is part of the research conducted for my doctoral thesis, 'Controlling in hetergenous economic envirnoments', under the coordination and supervision of Prof.Dr.Dumitru Matis. Keywords: Controlling, Management Accounting, Management Control, Accounting, Internal audit JEL Code: M49

  10. Neural Flight Control System

    Science.gov (United States)

    Gundy-Burlet, Karen

    2003-01-01

    The Neural Flight Control System (NFCS) was developed to address the need for control systems that can be produced and tested at lower cost, easily adapted to prototype vehicles and for flight systems that can accommodate damaged control surfaces or changes to aircraft stability and control characteristics resulting from failures or accidents. NFCS utilizes on a neural network-based flight control algorithm which automatically compensates for a broad spectrum of unanticipated damage or failures of an aircraft in flight. Pilot stick and rudder pedal inputs are fed into a reference model which produces pitch, roll and yaw rate commands. The reference model frequencies and gains can be set to provide handling quality characteristics suitable for the aircraft of interest. The rate commands are used in conjunction with estimates of the aircraft s stability and control (S&C) derivatives by a simplified Dynamic Inverse controller to produce virtual elevator, aileron and rudder commands. These virtual surface deflection commands are optimally distributed across the aircraft s available control surfaces using linear programming theory. Sensor data is compared with the reference model rate commands to produce an error signal. A Proportional/Integral (PI) error controller "winds up" on the error signal and adds an augmented command to the reference model output with the effect of zeroing the error signal. In order to provide more consistent handling qualities for the pilot, neural networks learn the behavior of the error controller and add in the augmented command before the integrator winds up. In the case of damage sufficient to affect the handling qualities of the aircraft, an Adaptive Critic is utilized to reduce the reference model frequencies and gains to stay within a flyable envelope of the aircraft.

  11. Common Control System Vulnerability

    Energy Technology Data Exchange (ETDEWEB)

    Trent Nelson

    2005-12-01

    The Control Systems Security Program and other programs within the Idaho National Laboratory have discovered a vulnerability common to control systems in all sectors that allows an attacker to penetrate most control systems, spoof the operator, and gain full control of targeted system elements. This vulnerability has been identified on several systems that have been evaluated at INL, and in each case a 100% success rate of completing the attack paths that lead to full system compromise was observed. Since these systems are employed in multiple critical infrastructure sectors, this vulnerability is deemed common to control systems in all sectors. Modern control systems architectures can be considered analogous to today's information networks, and as such are usually approached by attackers using a common attack methodology to penetrate deeper and deeper into the network. This approach often is composed of several phases, including gaining access to the control network, reconnaissance, profiling of vulnerabilities, launching attacks, escalating privilege, maintaining access, and obscuring or removing information that indicates that an intruder was on the system. With irrefutable proof that an external attack can lead to a compromise of a computing resource on the organization's business local area network (LAN), access to the control network is usually considered the first phase in the attack plan. Once the attacker gains access to the control network through direct connections and/or the business LAN, the second phase of reconnaissance begins with traffic analysis within the control domain. Thus, the communications between the workstations and the field device controllers can be monitored and evaluated, allowing an attacker to capture, analyze, and evaluate the commands sent among the control equipment. Through manipulation of the communication protocols of control systems (a process generally referred to as ''reverse engineering''), an

  12. Control power in perfect controlled teleportation via partially entangled channels

    OpenAIRE

    Li, Xi-Han; Ghose, Shohini

    2014-01-01

    We analyze and evaluate perfect controlled teleportation via three-qubit entangled channels from the point of view of the controller. The key idea in controlled teleportation is that the teleportation is performed only with the participation of the controller. We calculate a quantitative measure of the controller's power and establish a lower bound on the control power required for controlled teleportation. We show that the maximally entangled GHZ state is a suitable channel for controlled te...

  13. Study of the control-equilibrium of control systems

    Institute of Scientific and Technical Information of China (English)

    Liu Qiaoge; Fu Mengyin; Sun Changsheng

    2008-01-01

    Not so much had been talked about equilibrium in control area.On the basis of the phenomenon of balance,the concept of control-equilibrium and control-equilibrium of a control system is proposed.According to this theory,a perfect control method should not only guarantee stability of the system,but also ensure the control-equilibrium of the system.To achieve the control-equilibrium,feed-forward control is required.

  14. Event driven intelligent PID controllers with applications to motion control

    OpenAIRE

    Jing WANG; Mounier, Hugues; Cela, Arben; Niculescu, Silviu-Iulian

    2011-01-01

    International audience; A novel type of reduced complexity controller is proposed. It is the combination of model free control and event triggered control. The robustness of model free control, especially for badly known dynamics, is added to the event based scheme. The performances of the proposed method are illustrated in two motion controls, vehicular longitudinal control and quadrotor control. Comparisons with existing control schemes are also proposed.

  15. Load Control System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Trudnowski, Daniel [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  16. Advanced Wavefront Control Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, S S; Brase, J M; Avicola, K; Thompson, C A; Kartz, M W; Winters, S; Hartley, R; Wihelmsen, J; Dowla, F V; Carrano, C J; Bauman, B J; Pennington, D M; Lande, D; Sawvel, R M; Silva, D A; Cooke, J B; Brown, C G

    2001-02-21

    Programs at LLNL that involve large laser systems--ranging from the National Ignition Facility to new tactical laser weapons--depend on the maintenance of laser beam quality through precise control of the optical wavefront. This can be accomplished using adaptive optics, which compensate for time-varying aberrations that are often caused by heating in a high-power laser system. Over the past two decades, LLNL has developed a broad capability in adaptive optics technology for both laser beam control and high-resolution imaging. This adaptive optics capability has been based on thin deformable glass mirrors with individual ceramic actuators bonded to the back. In the case of high-power lasers, these adaptive optics systems have successfully improved beam quality. However, as we continue to extend our applications requirements, the existing technology base for wavefront control cannot satisfy them. To address this issue, this project studied improved modeling tools to increase our detailed understanding of the performance of these systems, and evaluated novel approaches to low-order wavefront control that offer the possibility of reduced cost and complexity. We also investigated improved beam control technology for high-resolution wavefront control. Many high-power laser systems suffer from high-spatial-frequency aberrations that require control of hundreds or thousands of phase points to provide adequate correction. However, the cost and size of current deformable mirrors can become prohibitive for applications requiring more than a few tens of phase control points. New phase control technologies are becoming available which offer control of many phase points with small low-cost devices. The goal of this project was to expand our wavefront control capabilities with improved modeling tools, new devices that reduce system cost and complexity, and extensions to high spatial and temporal frequencies using new adaptive optics technologies. In FY 99, the second year of

  17. Nonlinear optimal control theory

    CERN Document Server

    Berkovitz, Leonard David

    2012-01-01

    Nonlinear Optimal Control Theory presents a deep, wide-ranging introduction to the mathematical theory of the optimal control of processes governed by ordinary differential equations and certain types of differential equations with memory. Many examples illustrate the mathematical issues that need to be addressed when using optimal control techniques in diverse areas. Drawing on classroom-tested material from Purdue University and North Carolina State University, the book gives a unified account of bounded state problems governed by ordinary, integrodifferential, and delay systems. It also dis

  18. ROV Motion Control Systems

    OpenAIRE

    Dukan, Fredrik

    2014-01-01

    This thesis is about automatic motion control systems for remotely operated vehicles (ROV). The work has focused on topics within guidance and navigation. In addition, a motion control system has been developed, implemented, tested and used on two ROVs in sea trials.The main motivation for the work has been the need to automate ROV tasks in order to make the ROV a more efficient tool for exploring the ocean space. Many parts of a motion control system for a ROV is similar to that of surface v...

  19. Emerging Engine Control Technologies

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Chevalier, Alain

    1996-01-01

    In earlier work published by the author and co-authors, a dynamic model called a Mean Value Engine Model (MVEM) was developed. This model is physically based and is intended mainly for control applications. It is especially well suited to embedded model applications in engine controllers, susch...... as nonlinear observer based air/fuel ratio and advanced idle speed control. After a brief review of this model, it will be compared with other similar models which can be found in the literature. The attempt will be made to point out the differences between the new modified MVEM and those developed elsewhere...

  20. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2001-12-21

    Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandgaps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping, isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control.

  1. Telerik WPF controls tutorial

    CERN Document Server

    Spalding, Daniel

    2014-01-01

    Telerik Reporting is a lightweight reporting solution for all .NET cloud, web, and desktop platforms (Azure, Silverlight, WPF, ASP.NET, and Windows Forms) which targets developers and end users alike. Rich interactive and reusable reports can be created by developers in Visual Studio and by end users in the desktop-based Report Designer. This book will guide you through working with specific Telerik WPF controls as well as working with the database and other methods to load the controls. It will focus on four key technologies: the DataContext property of WPF, Telerik RadControls for WPF, XML s

  2. Radiological Control Manual

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records.

  3. Control system integration

    CERN Document Server

    Shea, T J

    2008-01-01

    This lecture begins with a definition of an accelerator control system, and then reviews the control system architectures that have been deployed at the larger accelerator facilities. This discussion naturally leads to identification of the major subsystems and their interfaces. We shall explore general strategies for integrating intelligent devices and signal processing subsystems based on gate arrays and programmable DSPs. The following topics will also be covered: physical packaging; timing and synchronization; local and global communication technologies; interfacing to machine protection systems; remote debugging; configuration management and source code control; and integration of commercial software tools. Several practical realizations will be presented.

  4. [Quality control in anesthesiology].

    Science.gov (United States)

    Muñoz-Ramón, J M

    1995-03-01

    The process of quality control and auditing of anesthesiology allows us to evaluate care given by a service and solve problems that are detected. Quality control is a basic element of care giving and is only secondarily an area of academic research; it is therefore a meaningless effort if the information does not serve to improve departmental procedures. Quality assurance procedures assume certain infrastructural requirements and an initial period of implementation and adjustment. The main objectives of quality control are the reduction of morbidity and mortality due to anesthesia, assurance of the availability and proper management of resources and, finally, the well-being and safety of the patient. PMID:7777688

  5. Radiological Control Manual

    International Nuclear Information System (INIS)

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records

  6. Mix/Cast Contamination Control

    Science.gov (United States)

    Wallentine, M.

    2005-01-01

    Presented is a training handbook for Mix/Cast Contamination Control; a part of a series of training courses to qualify access to Mix/Cast facilities. Contents: List Contamination Control Requirements; Identify foreign objects debris (FOD), Control Areas and their guidelines; Describe environmental monitoring; List Contamination Control Initiatives; Describe concern for Controlled Materials; Identify FOD Controlled Areas in Mix/Cast.

  7. Nonholonomic mechanics and control

    CERN Document Server

    Murray, RM

    2015-01-01

    This book explores some of the connections between control theory and geometric mechanics; that is, control theory is linked with a geometric view of classical mechanics in both its Lagrangian and Hamiltonian formulations and in particular with the theory of mechanical systems subject to motion constraints. The synthesis of the topic is appropriate as there is a particularly rich connection between mechanics and nonlinear control theory. The book provides a unified treatment of nonlinear control theory and constrained mechanical systems and illustrates the elegant mathematics behind many simple, interesting, and useful mechanical examples. It is intended for graduate students who wish to learn this subject and researchers in the area who want to enhance their techniques. The book contains sections focusing on physical examples and elementary terms, as well as theoretical sections that use sophisticated analysis and geometry. The first four chapters offer preliminaries and background information, while the...

  8. Satellite Control Laboratory

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Bak, Thomas

    2001-01-01

    The Satellite Laboratory at the Department of Control Engineering of Aalborg University (SatLab) is a dynamic motion facility designed for analysis and test of micro spacecraft. A unique feature of the laboratory is that it provides a completely gravity-free environment. A test spacecraft...... of the laboratory is to conduct dynamic tests of the control and attitude determination algorithms during nominal operation and in abnormal conditions. Further it is intended to use SatLab for validation of various algorithms for fault detection, accommodation and supervisory control. Different mission objectives...... can be implemented in the laboratory, e.g. three-axis attitude control, slew manoeuvres, spins stabilization using magnetic actuation and/or reaction wheels. The spacecraft attitude can be determined applying magnetometer measurements...

  9. Controllable tomography phase microscopy

    Science.gov (United States)

    Xiu, Peng; Zhou, Xin; Kuang, Cuifang; Xu, Yingke; Liu, Xu

    2015-03-01

    Tomography phase microscopy (TPM) is a new microscopic method that can quantitatively yield the volumetric 3D distribution of a sample's refractive index (RI), which is significant for cell biology research. In this paper, a controllable TPM system is introduced. In this system a circulatory phase-shifting method and piezoelectric ceramic are used which enable the TPM system to record the 3D RI distribution at a more controllable speed, from 1 to 40 fps, than in the other TPM systems reported. The resolution of the RI distribution obtained by this controllable TPM is much better than that in images recorded by phase contrast microscopy and interference tomography microscopy. The realization of controllable TPM not only allows for the application of TPM to the measurement of kinds of RI sample, but also contributes to academic and technological support for the practical use of TPM.

  10. Cardiovascular control during exercise

    DEFF Research Database (Denmark)

    Dela, Flemming; Mohr, Thomas; Jensen, Christina M R;

    2003-01-01

    We studied the role of the central nervous system, neural feedback from contracting skeletal muscles, and sympathetic activity to the heart in the control of heart rate and blood pressure during 2 levels of dynamic exercise....

  11. Wind Farm Control Survey

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas; Svenstrup, Mikael

    2013-01-01

    This document is a delivery in the project NORCOWE. It is part of work package WP3.2.2. The main goal is to establish the present state-of-the-art for wind farm control for both research and practice. The main approach will be to study the literature. This will of cause be much more efficient...... for the research part than for the practice part. It is however not the intention to do company interviews or similar. This report is structured into a section for each WF control objective. These sections then includes the important control project issues: choice of input and output, control method, and modelling...... turbine farm based on a dynamic programming type of method....

  12. Distributed Control Diffusion

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh

    2007-01-01

    . Programming a modular, self-reconfigurable robot is however a complicated task: the robot is essentially a real-time, distributed embedded system, where control and communication paths often are tightly coupled to the current physical configuration of the robot. To facilitate the task of programming modular......, self-reconfigurable robots, we present the concept of distributed control diffusion: distributed queries are used to identify modules that play a specific role in the robot, and behaviors that implement specific control strategies are diffused throughout the robot based on these role assignments....... This approach allows the programmer to dynamically distribute behaviors throughout a robot and moreover provides a partial abstraction over the concrete physical shape of the robot. We have implemented a prototype of a distributed control diffusion system for the ATRON modular, self-reconfigurable robot...

  13. Comfort control in buildings

    CERN Document Server

    Castilla, Maria del Mar; Rodriguez, Francisco de Asis

    2014-01-01

    This book describes both concepts and development of advanced comfort control systems in buildings, with significant energy saving, and attention to thermal, visual and indoor air quality. The concepts are proven through real tests in a bioclimatic building.

  14. Control of Pesticides 2006

    DEFF Research Database (Denmark)

    Krongaard, Teddy; Petersen, Kitty Kastalag; Christoffersen, Christel

    analytical chemical authority control: Herbicides containing metamitron, propaquizafop and haloxyfop-ethoxyethyl. Fungicides containing azoxystrobin, propiconazole, cyprodinil, picoxystrobin and fenpropidin. Insecticides containing pirimicarb. Plant growth regulators containing chlormequat chloride, mepiquat...

  15. Corporate Control and Underinvestment

    DEFF Research Database (Denmark)

    Poulsen, Thomas

    2013-01-01

    of the model developed by Myers and Majluf (J Financial Econ 13:187–221, 1984), I show that underinvestment is aggravated when there are benefits of being in control and these benefits are diluted if equity is issued to finance an investment project. Using a large panel of US data, I find that the concerns......This paper reports a study of how the benefits that large shareholders derive from their control of a firm affect the equity issue and investment decisions of the firm. I introduce an explicit agency cost structure based on the benefits of control of the largest shareholder. In a simple extension...... of large shareholders about the dilution of ownership and control cause firms to issue less equity and to invest less than would otherwise be the case. I also find that it makes no significant difference whether new shares are issued to old shareholders or new shareholders....

  16. Crowd Control Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Crowd Control Plan for Swan Lake National Wildlife Refuge outlines operational procedures in the event of a civil disorder on the Refuge. An inventory of...

  17. Tight Diabetes Control

    Science.gov (United States)

    ... Size: A A A Listen En Español Tight Diabetes Control Keeping your blood glucose levels as close ... and syringes, than before. What About Type 2 Diabetes? The DCCT studied only people with type 1 ...

  18. Health Center Controlled Network

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Health Center Controlled Network (HCCN) tool is a locator tool designed to make data and information concerning HCCN resources more easily available to our...

  19. Model-free control

    Science.gov (United States)

    Fliess, Michel; Join, Cédric

    2013-12-01

    'Model-free control'and the corresponding 'intelligent' PID controllers (iPIDs), which already had many successful concrete applications, are presented here for the first time in an unified manner, where the new advances are taken into account. The basics of model-free control is now employing some old functional analysis and some elementary differential algebra. The estimation techniques become quite straightforward via a recent online parameter identification approach. The importance of iPIs and especially of iPs is deduced from the presence of friction. The strange industrial ubiquity of classic PIDs and the great difficulty for tuning them in complex situations is deduced, via an elementary sampling, from their connections with iPIDs. Several numerical simulations are presented which include some infinite-dimensional systems. They demonstrate not only the power of our intelligent controllers but also the great simplicity for tuning them.

  20. Active control of convection

    Energy Technology Data Exchange (ETDEWEB)

    Bau, H.H. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-12-31

    Using stability theory, numerical simulations, and in some instances experiments, it is demonstrated that the critical Rayleigh number for the bifurcation (1) from the no-motion (conduction) state to the motion state and (2) from time-independent convection to time-dependent, oscillatory convection in the thermal convection loop and Rayleigh-Benard problems can be significantly increased or decreased. This is accomplished through the use of a feedback controller effectuating small perturbations in the boundary data. The controller consists of sensors which detect deviations in the fluid`s temperature from the motionless, conductive values and then direct actuators to respond to these deviations in such a way as to suppress the naturally occurring flow instabilities. Actuators which modify the boundary`s temperature/heat flux are considered. The feedback controller can also be used to control flow patterns and generate complex dynamic behavior at relatively low Rayleigh numbers.

  1. Birth control pills overdose

    Science.gov (United States)

    ... control pills and use other methods to prevent pregnancy, if desired. The overdose is NOT likely to be life-threatening. Before Calling Emergency Have this information ready: Person's age, weight, and ...

  2. Insecticides and Biological Control

    Science.gov (United States)

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  3. Engineering of metabolic control

    Science.gov (United States)

    Liao, James C.

    2006-10-17

    The invention features a method of producing heterologous molecules in cells under the regulatory control of a metabolite and metabolic flux. The method can enhance the synthesis of heterologous polypeptides and metabolites.

  4. Key to Network Controllability

    CERN Document Server

    Banerjee, Soumya Jyoti

    2012-01-01

    Liu et al recently proposed a minimum number of driver nodes needed to obtain full structural controllability over a directed network. Driver nodes are unmatched nodes, from which there are directed paths to all matched nodes. Their most important assertion is that a system's controllability is to a great extent encoded by the underlying network's degree distribution, $P(k_{in}, k_{out})$. Is the controllability of a network decided almost completely by the immediate neighbourhood of a node, while, even slightly distant nodes play no role at all? Motivated by the above question, in this communication, we argue that an effective understanding of controllability in directed networks can be reached using distance based measures of closeness centrality and betweenness centrality and may not require the knowledge of local connectivity measures like in-degree and out-degree.

  5. Satellite Control Laboratory

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Bak, Thomas

    2001-01-01

    The Satellite Laboratory at the Department of Control Engineering of Aalborg University (SatLab) is a dynamic motion facility designed for analysis and test of micro spacecraft. A unique feature of the laboratory is that it provides a completely gravity-free environment. A test spacecraft...... of the laboratory is to conduct dynamic tests of the control and attitude determination algorithms during nominal operation and in abnormal conditions. Further it is intended to use SatLab for validation of various algorithms for fault detection, accommodation and supervisory control. Different mission objectives...... can be implemented in the laboratory, e.g. three-axis attitude control, slew manoeuvres, spins stabilization using magnetic actuation and/or reaction wheels. The spacecraft attitude can be determined applying magnetometer measurements....

  6. Control and Information Systems

    Directory of Open Access Journals (Sweden)

    Jiri Zahradnik

    2003-01-01

    Full Text Available The article deals with main tends of scientific research activities of Department of Control and Information Systems at the Faculty of Electrical Engineering of University of Zilina and its perspectives in this area.

  7. Artificial locomotion control

    DEFF Research Database (Denmark)

    Azevedo, Christine; Poignet, Philippe; Espiau, Bernard

    2004-01-01

    walking from descriptive (biomechanics) as well as explicative (neuroscience and physiology) points of view, the objective being to stress the relevant elements for the approach of robot control. The adopted principles are then: no joint trajectory tracking; explicit distinction and integration...... of postural and walking control; use of evolutive optimization objectives; on-line event handling and environment adaptation and anticipation. This leads to the synthesis of an original control scheme based on non-linear model predictive control: Trajectory Free NMPC. The movement is specified implicitly...... through coherent physical inequality constraints. Dynamic model and internal limitations of the system are part of the problem constraints. This work is validated by simulation results obtained for the Bip and Rabbit biped robots in various walking and standing situations and compared to human data...

  8. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S.A.

    requirements for a dedicated software environment for fault tolerant control systems design. The second detailed study addressed the detection of a fault event and determination of the failed component. A variety of algorithms were compared, based on two fault scenarios in the speed governor actuator setup......This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component...... failures. It is often feasible to increase availability for these control loops by designing the control system to perform on-line detection and reconfiguration in case of faults before the safety system makes a close-down of the process. A general development methodology is given in the thesis...

  9. Fuzzy logic control

    Directory of Open Access Journals (Sweden)

    Zoltan Erdei

    2011-12-01

    Full Text Available In this paper the authors present the usefulness of fuzzy logic in controlling engineering processes or applications. Although fuzzy logic does not represent a novelty for the scientific and engineering field, it enjoys a great appreciation from those involved in the two domains. The fact that fuzzy logic uses sentences kindred with the natural language make it easier to comprehend that a complex mathematical model required by the classic control theory. In MatLab software there are dedicated toolboxes to this subject that make the design of a fuzzy controller a facile one. In the paper design methods of a fuzzy controller are being presented both in Simulink and MatLab.

  10. Fine motor control

    Science.gov (United States)

    ... figure out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To have fine motor control, children need: Awareness and planning Coordination ...

  11. Controlling refinery risk management

    OpenAIRE

    Lucy, Richard F.

    1991-01-01

    The purpose of this paper is to explore the determinants of internal control and propose techniques that can be utilized by the crude oil refiner in designing, implementing and controlling a pro-active risk management program. Since the introduction of volatility into the oil business in the mid-1970s, pro-active risk management the has become a popular tool for petroleum industry management to effectively reduce the firm1s exposure to price risk. In order to us...

  12. An intelligent CPIB controller

    International Nuclear Information System (INIS)

    An intelligent GPIB (General Purpose Interface Bus) controller is described. It employs an autonomous slave CPU together with a dedicated controller/talker/listener chip to handle the GPIB bus protocol, thus freeing the host computer from this time-consuming task. Distribution of a large part of the necessary software to the slave side, assures that the system can be implemented on virtually any computer with a minimum of effort

  13. Control and Syntagmatization

    DEFF Research Database (Denmark)

    Engerer, Volkmar Paul

    2016-01-01

    ., whereas thesaurus terms must be effective, current and relevant, searchable etc. The differences in vocabulary properties correlate with two other factors, the well-known dimension of Control (deliberate, social activities of building and maintaining vocabularies), and Syntagmatization, which is less...... known and describes vocabulary items’ varying formal preparedness to exit the thesaurus/lexicon, enter into linear syntactic constructions and, finally, acquire communicative functionality. It is proposed that there is an inverse relationship between Control and Syntagmatization....

  14. Control of schistosomiasis transmission

    OpenAIRE

    Luiz C. de S. Dias; Oswaldo Marçal Jr.; GLASSER Carmem M.

    1995-01-01

    Despite the success of control programmes, schistosomiasis is still a serious public health problem in the world. More than 70 countries where 200 million individuals are evaluated to be infected of a total 600 million at risk. Though there have been important local success in the control of transmission, globally the infection has increased. Economic constrains in developing countries, environmental changes associated with migration and water resources development have been blocking the prog...

  15. Drone Control System

    Science.gov (United States)

    1983-01-01

    Drones, subscale vehicles like the Firebees, and full scale retired military aircraft are used to test air defense missile systems. The DFCS (Drone Formation Control System) computer, developed by IBM (International Business Machines) Federal Systems Division, can track ten drones at once. A program called ORACLS is used to generate software to track and control Drones. It was originally developed by Langley and supplied by COSMIC (Computer Software Management and Information Center). The program saved the company both time and money.

  16. Elevator Control Strategies

    OpenAIRE

    Ceder, Frederick; Nordin, Alexandra

    2013-01-01

    This paper investigates the efficiency of known elevator control strategies by simulating these in an own made apartment simulator. Efficiency will be determined by the lowest product of the energy consumption (Watt/second), average waiting time, average transfer time and the maximum waiting time of a passenger, which is the output by the simulator. The apartment simulator will simulate the elevator behavior, according to a respective control strategy, and the passenger flow on each respectiv...

  17. Magnetic spectrometer control system

    International Nuclear Information System (INIS)

    The design and implementation of a new computerized control system for the several devices of the magnetic spectrometer at TANDAR Laboratory is described. This system, as a main difference from the preexisting one, is compatible with almost any operating systems of wide spread use available in PC. This allows on-line measurement and control of all signals from any terminal of a computer network. (author)

  18. Organic traffic control

    OpenAIRE

    Prothmann, Holger

    2011-01-01

    Modern cities cannot be imagined without traffic lights controlling the road network. To handle the network's changing demands efficiently, the signal plan specification needs to be shifted from the design time to the run-time of a signal system. The generic observer/controller architecture proposed for Organic Computing facilitates this shift. A two-levelled learning mechanism optimises signal plans on-line while a distributed coordination mechanism establishes green waves in the road network.

  19. Robust Adaptive Control

    Science.gov (United States)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  20. Cell control report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This extensive report provides an essential overview of cells and their use as factory automation building blocks. The following issues are discussed in depth: Cell integration Cell software and standards Future technologies applied to cells Plus Cell control applications including: - rotary parts manufacturing - diesel engine component development - general cell control development at the General Electric Corporation - a vendor list.